Last data update: Apr 22, 2024. (Total: 46599 publications since 2009)
Records 1-30 (of 57 Records) |
Query Trace: Moura I [original query] |
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From cultivation to cancer: formation of N-nitrosamines and other carcinogens in smokeless tobacco and their mutagenic implications
Stanfill SB , Hecht SS , Joerger AC , González PJ , Maia LB , Rivas MG , Moura JJG , Gupta AK , Le Brun NE , Crack JC , Hainaut P , Sparacino-Watkins C , Tyx RE , Pillai SD , Zaatari GS , Henley SJ , Blount BC , Watson CH , Kaina B , Mehrotra R . Crit Rev Toxicol 2023 53 (10) 1-44 Tobacco use is a major cause of preventable morbidity and mortality globally. Tobacco products, including smokeless tobacco (ST), generally contain tobacco-specific N-nitrosamines (TSNAs), such as N′-nitrosonornicotine (NNN) and 4-(methylnitrosamino)-1-(3-pyridyl)-butanone (NNK), which are potent carcinogens that cause mutations in critical genes in human DNA. This review covers the series of biochemical and chemical transformations, related to TSNAs, leading from tobacco cultivation to cancer initiation. A key aim of this review is to provide a greater understanding of TSNAs: their precursors, the microbial and chemical mechanisms that contribute to their formation in ST, their mutagenicity leading to cancer due to ST use, and potential means of lowering TSNA levels in tobacco products. TSNAs are not present in harvested tobacco but can form due to nitrosating agents reacting with tobacco alkaloids present in tobacco during certain types of curing. TSNAs can also form during or following ST production when certain microorganisms perform nitrate metabolism, with dissimilatory nitrate reductases converting nitrate to nitrite that is then released into tobacco and reacts chemically with tobacco alkaloids. When ST usage occurs, TSNAs are absorbed and metabolized to reactive compounds that form DNA adducts leading to mutations in critical target genes, including the RAS oncogenes and the p53 tumor suppressor gene. DNA repair mechanisms remove most adducts induced by carcinogens, thus preventing many but not all mutations. Lastly, because TSNAs and other agents cause cancer, previously documented strategies for lowering their levels in ST products are discussed, including using tobacco with lower nornicotine levels, pasteurization and other means of eliminating microorganisms, omitting fermentation and fire-curing, refrigerating ST products, and including nitrite scavenging chemicals as ST ingredients. ©, This work was authored as part of the Contributor's official duties as an Employee of the United States Government and is therefore a work of the United States Government. In accordance with 17 U.S.C. 105, no copyright protection is available for such works under U.S. Law. |
Emergence and global spread of Listeria monocytogenes main clinical clonal complex (preprint)
Moura A , Lefrancq N , Leclercq A , Wirth T , Borges V , Gilpin B , Dallman TJ , Frey J , Franz E , Nielsen EM , Thomas J , Pightling A , Howden BP , Tarr CL , Gerner-Smidt P , Cauchemez S , Salje H , Brisse S , Lecuit M . bioRxiv 2020 2020.12.18.423387 Retracing microbial emergence and spread is essential to understanding the evolution and dynamics of pathogens. The bacterial foodborne pathogen Listeria monocytogenes clonal complex 1 (Lm-CC1) is the most prevalent clonal group associated with listeriosis, and is strongly associated with cattle and dairy products. Here we analysed 2,021 Lm-CC1 isolates collected from 40 countries, since the first Lm isolation to the present day, to define its evolutionary history and population dynamics. Our results suggest that Lm-CC1 spread worldwide from North America following the Industrial Revolution through two waves of expansion, coinciding with the transatlantic livestock trade in the second half of the 19th century and the rapid growth of cattle farming in the 20th century. Lm-CC1 then firmly established at a local level, with limited inter-country spread. This study provides an unprecedented insight into Lm-CC1 phylogeography and dynamics and can contribute to effective disease surveillance to reduce the burden of listeriosis.Competing Interest StatementThe authors have declared no competing interest. |
The importance of understanding neighborhood environments in neurology care
Kobau R , Moura LMVR . Neurology 2023 100 (23) 1079-1080 Compared with US adults without epilepsy, adults with epilepsy are more likely to report an inability to afford prescription medicine and specialty care and delayed care because of transportation barriers or were in families having problems paying medical bills.1 Although social needs (e.g., public transportation and medication assistance programs) are experienced at the individual level, they may reflect community-level resources that, when present, foster health and, when absent, thwart it. Social determinants of health (SDOH) include the social, economic, institutional, and environmental factors that affect health outcomes.2,3 Although substantial research has documented disparities in individual-level social needs in people with epilepsy, scant research exists examining associations between community-level SDOH and epilepsy outcomes.3-5 |
Drivers of US healthcare spending for persons with seizures and/or epilepsies, 2010-2018
Moura Lmvr , Karakis I , Zack MM , Tian N , Kobau R , Howard D . Epilepsia 2022 63 (8) 2144-2154 OBJECTIVE: To characterize spending for persons classified with seizure or epilepsy and determine if spending has increased over time. METHODS: In this cross-sectional study we pooled data from the Medical Expenditure Panel Survey (MEPS) household component files for 2010 to 2018. We matched cases to controls on age and sex of a population-based sample of MEPS respondents (community-dwelling persons of all ages) with records associated with a medical event (e.g., outpatient visit; hospital inpatient) for seizure, epilepsy, or both. Outcomes were weighted to be representative of the civilian, non-institutionalized population. We estimated the treated prevalence of epilepsy and seizure, healthcare spending overall and by site of care, and trends in spending growth. RESULTS: We identified 1,078 epilepsy cases, and 2,344 seizure cases. Treated prevalence was 0.38% (95% CI =0.34-0.41) for epilepsy, 0.76% (95% CI=0.71-0.81) for seizure, and 1.14% (95% CI: 1.08-1.20) for epilepsy or seizure. The difference in annual spending for cases compared to controls was $4,580 (95% CI: $3,362-$5,798) for epilepsy, $7,935 (95% CI: $6,237-$9,634) for seizure, and $6,853 (95% CI: $5,623-$8,084) for epilepsy or seizure, translating into aggregate costs of $5.4 billion, $19.0 billion, and $24.5 billion. From 2010 to 2018, the annual growth rate in total spending incurred for seizures and/or epilepsies was 7.6% compared to 3.6% among controls. SIGNIFICANCE: U.S. economic burden of seizures and/or epilepsies is substantial and warrants interventions focused on their unique and overlapping causes. |
Emergence and global spread of Listeria monocytogenes main clinical clonal complex.
Moura A , Lefrancq N , Wirth T , Leclercq A , Borges V , Gilpin B , Dallman TJ , Frey J , Franz E , Nielsen EM , Thomas J , Pightling A , Howden BP , Tarr CL , Gerner-Smidt P , Cauchemez S , Salje H , Brisse S , Lecuit M . Sci Adv 2021 7 (49) eabj9805 Retracing microbial emergence and spread is essential to understanding the evolution and 40 dynamics of pathogens. The bacterial foodborne pathogen Listeria monocytogenes clonal 41 complex 1 (Lm-CC1) is the most prevalent clonal group associated with listeriosis, and is 42 strongly associated with cattle and dairy products. Here we analysed 2,021 Lm-CC1 43 isolates collected from 40 countries, since the first Lm isolation to the present day, to 44 define its evolutionary history and population dynamics. Our results suggest that Lm-CC1 45 spread worldwide from North America following the Industrial Revolution through two 46 waves of expansion, coinciding with the transatlantic livestock trade in the second half of 47 the 19th century and the rapid growth of cattle farming in the 20th century. Lm-CC1 then 48 firmly established at a local level, with limited inter-country spread. This study provides 49 an unprecedented insight into Lm-CC1 phylogeography and dynamics and can contribute 50 to effective disease surveillance to reduce the burden of listeriosis. |
Linking the Paul Coverdell National Acute Stroke Program to commercial claims to establish a framework for real-world longitudinal stroke research
Patorno E , Schneeweiss S , George MG , Tong X , Franklin JM , Pawar A , Mogun H , Moura Lmvr , Schwamm LH . Stroke Vasc Neurol 2021 7 (2) 114-123 BACKGROUND: Non-interventional large-scale research on real-world patients who had a stroke requires the use of multiple data sources ensuring access to longitudinal data from large populations with clinically-detailed information. We sought to establish a framework for longitudinal research on patients hospitalised with stroke by linking information-rich, deidentified inpatient data from the Paul Coverdell National Acute Stroke Program (PCNASP) to commercial and Medicare Advantage longitudinal claims data. METHODS: All stroke admissions in PCNASP between 2008 and 2015 were evaluated for linkage to longitudinal claims from a commercial insurer using an algorithm based on six available common data fields (patient age, gender, admission date, discharge date, discharge diagnosis and state) and a hospital match. We evaluated the linkage quality (via the percentage of unique records in the linked dataset) and the representativeness of the linked population. We also described medical history, stroke severity and patterns of medication use among the PCNASP-claims linked cohort. RESULTS: The linkage produced uniqueness equal to 99.1%. We identified 5644 linked and 98 896 unlinked patients who had an ischaemic stroke hospitalisation in claims data. Linked patients were younger than unlinked (69.7 vs 72.5 years), but otherwise similar by medical history, prestroke medication use or lab values. Stroke severity was mild and most patients were discharged home. Prestroke and discharge use of antihypertensive and statins in the PCNASP were greater than their use as measured by filled prescriptions in claims. CONCLUSIONS: High-quality linkage between the PCNASP and commercial claims data is feasible. This linkage identified differences between reported or recommended versus actual out-of-hospital medication utilisation, highlighting the importance of longitudinal data availability for research aimed to improve the care of patients who had a stroke. |
Exoproteomic analysis of two MLST clade 2 strains of Clostridioides difficile from Latin America reveal close similarities.
de Melo Pacífico D , Costa CL , Moura H , Barr JR , Maia GA , Filho VB , Moreira RS , Wagner G , Domingues Rmcp , Quesada-Gómez C , de Oliveira Ferreira E , de Castro Brito GA . Sci Rep 2021 11 (1) 13273 Clostridioides difficile BI/NAP1/ribotype 027 is an epidemic hypervirulent strain found worldwide, including in Latin America. We examined the genomes and exoproteomes of two multilocus sequence type (MLST) clade 2 C. difficile strains considered hypervirulent: ICC-45 (ribotype SLO231/UK[CE]821), isolated in Brazil, and NAP1/027/ST01 (LIBA5756), isolated during a 2010 outbreak in Costa Rica. C. difficile isolates were cultured and extracellular proteins were analyzed using high-performance liquid chromatography-tandem mass spectrometry. Genomic analysis revealed that these isolates shared most of the gene composition. Only 83 and 290 NAP1/027 genes were considered singletons in ICC-45 and NAP1/027, respectively. Exoproteome analysis revealed 197 proteins, of which 192 were similar in both strains. Only five proteins were exclusive to the ICC-45 strain. These proteins were involved with catalytic and binding functions and indirectly interacted with proteins related to pathogenicity. Most proteins, including TcdA, TcdB, flagellin subunit, and cell surface protein, were overrepresented in the ICC-45 strain; 14 proteins, including mature S-layer protein, were present in higher proportions in LIBA5756. Data are available via ProteomeXchange with identifier PXD026218. These data show close similarity between the genome and proteins in the supernatant of two strains with hypervirulent features isolated in Latin America and underscore the importance of epidemiological surveillance of the transmission and emergence of new strains. |
MALDI-TOF MS: an alternative approach for ribotyping Clostridioides difficile isolates in Brazil.
Gouveia CL , Abreu PTC , Hercules M , John B , Cavalcanti Pilotto DRM , de Oliveira FE . Anaerobe 2021 69 102351 Clostridioides difficile is an important organism causing healthcare-associated infections. It has been documented that specific strains caused multiple outbreaks globally, and patients infected with those strains are more likely to develop severe C. difficile infection (CDI). With the appearance of a variant strain, BI/NAP1 ribotype 027, responsible for several outbreaks and high mortality rates worldwide, the epidemiology of the CDI changed drastically in the United States, Europe, and some Latin American countries. Although the epidemic strain 027 was not yet detected in Brazil, there are ribotypes exclusively found in the country, such as, 131, 132, 133, 135, 142 and 143, which are responsible for outbreaks in Brazilian hospitals and nursing homes. Although PCR-ribotyping is the most used method in epidemiology studies of C. difficile, it is not available in Brazil. This study aimed to develop and validate an in-house database for detecting C. difficile ribotypes, usually involved in CDI in Brazilian hospitals, by using MALDI-TOF MS. A database with 19 different ribotypes, 13 with worldwide circulation and 6 Brazilian-restricted, was created based on 27 spectra readings of each ribotype. After BioNumerics analysis, neighbor-joining trees revealed that spectra were distributed in clusters according to ribotypes, showing that MALDI-TOF MS could discriminate all 19 ribotypes. Moreover, each ribotype showed a different profile with 42 biomarkers detected in total. Based on their intensity and occurrence, 13 biomarkers were chosen to compose ribotype-specific profiles, and in silico analysis showed that most of these biomarkers were uncharacterized proteins or well-conserved peptides, such as ribosomal proteins. A double-blind assessment using the 13 biomarkers correctly assigned the ribotype in 73% of the spectra analyzed, with 94% to 100% of correct hits for 027 and for Brazilian ribotypes. Although further analyses are required, our results show that MALDI-TOF MS might be a reliable, fast and feasible alternative for epidemiological surveillance of C. difficile in Brazil. |
Dynamics of protein synthesis in the initial steps of strobilation in the model cestode parasite Mesocestoides corti (syn. vogae)
de Lima JC , Floriani MA , Debarba JA , Paludo GP , Monteiro KM , Moura H , Barr JR , Zaha A , Ferreira HB . J Proteomics 2020 228 103939 Mesocestoides corti (syn. vogae) is a useful model for developmental studies of platyhelminth parasites of the Cestoda class, such as Taenia spp. or Echinococcus spp. It has been used in studies to characterize cestode strobilation, i.e. the development of larvae into adult worms. So far, little is known about the initial molecular events involved in cestode strobilation and, therefore, we carried out a study to characterize newly synthesized (NS) proteins upon strobilation induction. An approach based on bioorthogonal noncanonical amino acid tagging and mass spectrometry was used to label, isolate, identify, and quantify NS proteins in the initial steps of M. corti strobilation. Overall, 121 NS proteins were detected exclusively after induction of strobilation, including proteins related to development pathways, such as insulin and notch signaling. Metabolic changes that take place in the transition from the larval stage to adult worm were noted in special NS protein subsets related to developmental processes, such as focal adhesion, cell leading edge, and maintenance of location. The data shed light on mechanisms underlying early steps of cestode strobilation and enabled identification of possible developmental markers. We also consider the use of developmental responsive proteins as potential drug targets for developing novel anthelmintics. BIOLOGICAL SIGNIFICANCE: Larval cestodiases are life-threatening parasitic diseases that affect both man and domestic animals worldwide. Cestode parasites present complex life cycles, in which they undergo major morphological and physiological changes in the transition from one life-stage to the next. One of these transitions occurs during cestode strobilation, when the mostly undifferentiated and non-segmented larval or pre-adult form develops into a fully segmented and sexually differentiated (strobilated) adult worm. Although the proteomes of bona fide larvae and strobialted adults have been previously characterized for a few cestode species, little is still known about the dynamic of protein synthesis during the early steps of cestode strobilation. Now, the assessment of newly synthesized (NS) proteins within the first 48 h of strobilation the model cestode M. corti allowed to shed light on molecular mechanisms that are triggered by strobilation induction. The functional analyses of this repertoire of over a hundred NS proteins pointed out to changes in metabolism and activation of classical developmental signaling pathways in early strobilation. Many of the identified NS proteins may become valuable cestode developmental markers and their involvement in vital processes make them also good candidate targets for novel anthelmintic drugs. |
Dried blood spots for Streptococcus pneumoniae and Haemophilus influenzae detection and serotyping among children < 5 years old in rural Mozambique.
Pimenta FC , Moiane B , Lessa FC , Venero AL , Moura I , Larson S , Massora S , Chauque A , Tembe N , Mucavele H , Verani JR , Whitney CG , Sigauque B , Carvalho MGS . BMC Pediatr 2020 20 (1) 326 BACKGROUND: Dried blood spots (DBS) have been proposed as potentially tool for detecting invasive bacterial diseases. METHODS: We evaluated the use of DBS for S. pneumoniae and H. influenzae detection among children in Mozambique. Blood for DBS and nasopharyngeal (NP) swabs were collected from children with pneumonia and healthy aged < 5 years. Bacterial detection and serotyping were performed by quantitative PCR (qPCR) (NP and DBS; lytA gene for pneumococcus and hpd for H. influenzae) and culture (NP). Combined detection rates were compared between children with pneumonia and healthy. RESULTS: Of 325 children enrolled, 205 had pneumonia and 120 were healthy. Pneumococci were detected in DBS from 20.5 and 64.2% of children with pneumonia and healthy, respectively; NP specimens were positive for pneumococcus in 80.0 and 80.8%, respectively. H. influenzae was detected in DBS from 22.9% of children with pneumonia and 59.2% of healthy; 81.4 and 81.5% of NP specimens were positive for H. influenzae, respectively. CONCLUSION: DBS detected pneumococcal and H. influenzae DNA in children with pneumonia and healthy. Healthy children were often DBS positive for both bacteria, suggesting that qPCR of DBS specimens does not differentiate disease from colonization and is therefore not a useful diagnostic tool for children. |
Meningococcal carriage in young adults six years after meningococcal C conjugate (MCC) vaccine catch-up campaign in Salvador, Brazil.
Ferreira VM , Ferreira IE , Chang HY , Nunes Ampb , Topaz N , Pimentel ER , Moura Arss , Ribeiro GS , Feitosa CA , Reis MG , Wang X , Campos LC . Vaccine 2020 38 (14) 2995-3002 Meningococcal carriage studies are important to improve the knowledge of disease epidemiology as well as to support appropriate vaccination strategies. We conducted a cross-sectional study to determine the prevalence and genotypic characteristics of meningococci collected from young adults in Salvador, Brazil six years after a meningococcal C conjugate vaccine catch-up campaign. From August through November 2016, oropharyngeal swabs were collected from 407 students aged 1824 years attending a private college in Salvador, Brazil. Neisseria meningitidis was identified by standard microbiology methods and real time PCR. Genetic characteristics of meningococci were assessed by rt-PCR and/or whole genome sequencing. We also investigated potential factors associated with carriage. N. meningitidis was detectable in 50 students, 39 by both culture and rt-PCR, 7 by culture alone and 4 by rt-PCR alone, resulting in an overall meningococcal carriage prevalence of 12.3% (50/407). Carriage was independently associated with male sex (adjusted PR: 1.97; 95% CI: 1.12-3.46; p = 0.018) and attending bars or parties at least once per month (aPR: 3.31; 95% CI: 1.49-7.38; p = 0.003). Molecular tests identified 92% (46/50) N. meningitidis as non-groupable, of which 63% (29/46) had the capsule null genotype; 14 NG isolates contained disrupted capsule backbones and belonged to the following genogroups: 7 B, 3 Z, 3 E and 1 W. One isolate belonged to genogroup C tested only by PCR; 3 isolates contained a complete B capsule backbones, 2 of which were determined to be NG by slide agglutination serogrouping. While most meningococcal carriage isolates were non-groupable, there was a high degree of genetic diversity present in the collection, as evidenced by 25 unique STs being detected. The carriage prevalence of meningococcal serogroup C was low among young adults. Continuous vaccination is important to maintain reduced meningococcal carriage and transmission, inducing herd protection. |
Unraveling oxidative stress response in the cestode parasite Echinococcus granulosus
Cancela M , Paes JA , Moura H , Barr JR , Zaha A , Ferreira HB . Sci Rep 2019 9 (1) 15876 Cystic hydatid disease (CHD) is a worldwide neglected zoonotic disease caused by Echinococcus granulosus. The parasite is well adapted to its host by producing protective molecules that modulate host immune response. An unexplored issue associated with the parasite's persistence in its host is how the organism can survive the oxidative stress resulting from parasite endogenous metabolism and host defenses. Here, we used hydrogen peroxide (H2O2) to induce oxidative stress in E. granulosus protoescoleces (PSCs) to identify molecular pathways and antioxidant responses during H2O2 exposure. Using proteomics, we identified 550 unique proteins; including 474 in H2O2-exposed PSCs (H-PSCs) samples and 515 in non-exposed PSCs (C-PSCs) samples. Larger amounts of antioxidant proteins, including GSTs and novel carbonyl detoxifying enzymes, such as aldo-keto reductase and carbonyl reductase, were detected after H2O2 exposure. Increased concentrations of caspase-3 and cathepsin-D proteases and components of the 26S proteasome were also detected in H-PSCs. Reduction of lamin-B and other caspase-substrate, such as filamin, in H-PSCs suggested that molecular events related to early apoptosis were also induced. We present data that describe proteins expressed in response to oxidative stress in a metazoan parasite, including novel antioxidant enzymes and targets with potential application to treatment and prevention of CHD. |
Intracellular changes of a swine tracheal cell line infected with a Mycoplasma hyopneumoniae pathogenic strain.
Leal Zimmer FMA , Moura H , Barr JR , Ferreira HB . Microb Pathog 2019 137 103717 Mycoplasma hyopneumoniae is the etiological agent of enzootic pneumonia (EP), a widespread disease that causes major economic losses to the pig industry. The swine host response plays an important role in the outcome of M. hyopneumoniae infections. The whole proteome of newborn pig trachea (NPTr) epithelial cells infected with the M. hyopneumoniae pathogenic strain 7448 was analyzed using an LC-MS/MS approach to shed light on intracellular processes triggered in response to the pathogen. Overall, 853 swine protein species were identified, 156 of which were differentially represented in response to M. hyopneumoniae 7448 infection in comparison with non-infected control cells. These differentially represented proteins were categorized by function. Fifty-seven of them were assigned to the immune system and/or response to stimulus functional subcategories. Comparative expression analysis of these immune-related proteins in NPTr cells infected with attenuated or non-pathogenic mycoplasmas (M. hyopneumoniae J strain and M. flocculare, respectively) revealed proteins whose abundance was altered only in response to the pathogenic M. hyopneumoniae 7448 strain. Among these proteins, calcium homeostasis and endoplasmic reticulum stress-related biomarkers were detected, providing evidence of molecular mechanisms that might lead to swine cell apoptosis. |
Messenger RNA levels of the Polo-like kinase gene (PLK) correlate with cytokinesis in the Trypanosoma rangeli cell cycle.
Prestes EB , Stoco PH , de Moraes MH , Moura H , Grisard EC . Exp Parasitol 2019 204 107727 BACKGROUND: Trypanosoma rangeli is a protozoan parasite that is non-virulent to the mammalian host and is morphologically and genomically related to Trypanosoma cruzi, whose proliferation within the mammalian host is controversially discussed. OBJECTIVES: We aimed to investigate the T. rangeli cell cycle in vitro and in vivo by characterizing the timespan of the parasite life cycle and by proposing a molecular marker to assess cytokinesis. METHODOLOGY: The morphological events and their timing during the cell cycle of T. rangeli epimastigotes were assessed using DNA staining, flagellum labelling and bromodeoxyuridine incorporation. Messenger RNA levels of four genes previously associated with the cell cycle of trypanosomatids (AUK1, PLK, MOB1 and TRACK) were evaluated in the different T. rangeli forms. FINDINGS: T. rangeli epimastigotes completed the cell cycle in vitro in 20.8h. PLK emerged as a potential molecular marker for cell division, as its mRNA levels were significantly increased in exponentially growing epimastigotes compared with growth-arrested parasites or in vitro-differentiated trypomastigotes. PLK expression in T. rangeli can be detected near the flagellum protrusion site, reinforcing its role in the cell cycle. Interestingly, T. rangeli bloodstream trypomastigotes exhibited very low mRNA levels of PLK and were almost entirely composed of parasites in G1 phase. MAIN CONCLUSIONS: Our work is the first to describe the T. rangeli cell cycle in vitro and proposes that PLK mRNA levels could be a useful tool to investigate the T. rangeli ability to proliferate within the mammalian host bloodstream. |
Lessons from the reestablishment of Public Health Laboratory activities in Puerto Rico after Hurricane Maria
Hardy MC , Stinnett RC , Kines KJ , Rivera-Nazario DM , Lowe DE , Mercante AM , Gonzalez Jimenez N , Cuevas Ruiz RI , Rivera Arbolay HI , Gonzalez Pena RL , Toro M , Trujillo AA , Pappas CL , Llewellyn AC , Candal F , Burgos Garay M , Gomez GA , Concepcion Acevedo J , Ansbro M , Moura H , Shaw MW , Muehlenbachs A , Romanoff LC , Sunshine BJ , Rose DA , Patel A , Shapiro CN , Luna-Pinto SC , Pillai SK , O'Neill E . Nat Commun 2019 10 (1) 2720 Public Health Laboratories (PHLs) in Puerto Rico did not escape the devastation caused by Hurricane Maria. We implemented a quality management system (QMS) approach to systematically reestablish laboratory testing, after evaluating structural and functional damage. PHLs were inoperable immediately after the storm. Our QMS-based approach began in October 2017, ended in May 2018, and resulted in the reestablishment of 92% of baseline laboratory testing capacity. Here, we share lessons learned from the historic recovery of the largest United States' jurisdiction to lose its PHL capacity, and provide broadly applicable tools for other jurisdictions to enhance preparedness for public health emergencies. |
Vagococcus bubulae sp. nov., isolated from ground beef, and Vagococcus vulneris sp. nov., isolated from a human foot wound.
Shewmaker PL , Whitney AM , Gulvik CA , Humrighouse BW , Gartin J , Moura H , Barr JR , Moore ERB , Karlsson R , Pinto TCA , Teixeira LM . Int J Syst Evol Microbiol 2019 69 (8) 2268-2276 Two unusual catalase-negative, Gram-stain-positive, Vagococcus-like isolates that were referred to the CDC Streptococcus Laboratory for identification are described. Strain SS1994(T) was isolated from ground beef and strain SS1995(T) was isolated from a human foot wound. Comparative 16S rRNA gene sequence analysis of isolates SS1994(T) and SS1995(T) against Vagococcus type strain sequences supported their inclusion in the genus Vagococcus. Strain SS1994(T) showed high sequence similarity (>97.0 %) to the two most recently proposed species, Vagococcus martis (99.2 %) and Vagococcus teuberi (99.0 %) followed by Vagococcus penaei (98.8 %), strain SS1995(T) (98.6 %), Vagococcus carniphilus (98.0 %), Vagococcus acidifermentans (98.0 %) and Vagococcus fluvialis (97.9 %). The 16S rRNA gene sequence of strain SS1995(T) was most similar to V. penaei (99.1 %), followed by SS1994(T) (98.6 %), V. martis (98.4 %), V. teuberi (98.1 %), V. acidifermentans (97.8 %), and both V. carniphilus and V. fluvialis (97.5 %). A polyphasic taxonomic study using conventional biochemical and the rapid ID 32 STREP system, MALDI-TOF MS, cell fatty acid analysis, pairwise sequence comparisons of the 16S rRNA, rpoA, rpoB, pheS and groL genes, and comparative core and whole genome sequence analyses revealed that strains SS1994(T) and SS1995(T) were two novel Vagococcus species. The novel taxonomic status of the two isolates was confirmed with core genome phylogeny, average nucleotide identity <84 % and in silico DNA-DNA hybridization <28 % to any other Vagococcus species. The names Vagococcusbubulae SS1994(T)=(CCUG 70831(T)=LMG 30164(T)) and Vagococcusvulneris SS1995(T)=(CCUG 70832(T)=LMG 30165(T)) are proposed. |
Differential responses to stress of two Mycoplasma hyopneumoniae strains
Paes JA , Leal Zimmer FMA , Moura H , Barr JR , Ferreira HB . J Proteomics 2019 199 67-76 Mycoplasma hyopneumoniae is a respiratory pathogen, causing porcine enzootic pneumonia. To survive in the porcine respiratory tract, M. hyopneumoniae must cope with both oxidative and heat stress imposed by the host. To get insights into M. hyopneumoniae stress responses and pathogenicity mechanisms, the protein profiles of two M. hyopneumoniae strains, pathogenic 7448 strain and non-pathogenic strain J, were surveyed under oxidative (OS) or heat (HS) stress. M. hyopneumoniae strains were submitted to OS (0.5% hydrogen peroxide) or HS (temperature shifts to 42 degrees C) conditions and protein profiling was carried out by LC-MS/MS and label-free quantitative analyses. Data are available via ProteomeXchange with identifier PXD012742. Qualitative and quantitative differences involving 40-60M. hyopneumoniae proteins were observed for both strains when comparing bacteria exposed to OS or HS to non-treated controls. However, no differences in abundance were found in proteins classically related to stress responses, as peroxidases and chaperones, suggesting that these proteins would be constitutively present in both strains in the tested conditions. Interestingly, under stress conditions, more virulence-related proteins were detected in M. hyopneumoniae 7448 differentially represented proteins than in M. hyopneumoniae J, suggesting that stress may trigger a differential response of the corresponding genes, shared by both strains. |
Accurate and selective quantification of anthrax protective antigen in plasma by immunocapture and isotope dilution mass spectrometry
Solano MI , Woolfitt AR , Boyer AE , Lins RC , Isbell K , Gallegos-Candela M , Moura H , Pierce CL , Barr JR . Analyst 2019 144 (7) 2264-2274 Anthrax protective antigen (83 kDa, PA83) is an essential component of two major binary toxins produced by Bacillus anthracis, lethal toxin (LTx) and edema toxin (ETx). During infection, LTx and ETx contribute to immune collapse, endothelial dysfunction, hemorrhage and high mortality. Following protease cleavage on cell receptors or in circulation, the 20 kDa (PA20) N-terminus is released, activating the 63 kDa (PA63) form which binds lethal factor (LF) and edema factor (EF), facilitating their entry into their cellular targets. Several ELISA-based PA methods previously developed are primarily qualitative or semi-quantitative. Here, we combined protein immunocapture, tryptic digestion and isotope dilution liquid chromatography-mass spectrometry (LC-MS/MS), to develop a highly selective and sensitive method for detection and accurate quantification of total-PA (PA83 + PA63) and PA83. Two tryptic peptides in the 63 kDa region measure total-PA and three in the 20 kDa region measure PA83 alone. Detection limits range from 1.3-2.9 ng mL-1 PA in 100 muL of plasma. Spiked recovery experiments with combinations of PA83, PA63, LF and EF in plasma showed that PA63 and PA83 were quantified accurately against the PA83 standard and that LF and EF did not interfere with accuracy. Applied to a study of inhalation anthrax in rhesus macaques, total-PA suggested triphasic kinetics, similar to that previously observed for LF and EF. This study is the first to report circulating PA83 in inhalation anthrax, typically at less than 4% of the levels of PA63, providing the first evidence that activated PA63 is the primary form of PA throughout infection. |
Streptococcus infantis, Streptococcus mitis , and Streptococcus oralis Strains With Highly Similar cps5 Loci and Antigenic Relatedness to Serotype 5 Pneumococci.
Pimenta F , Gertz RE Jr , Park SH , Kim E , Moura I , Milucky J , Rouphael N , Farley MM , Harrison LH , Bennett NM , Bigogo G , Feikin DR , Breiman R , Lessa FC , Whitney CG , Rajam G , Schiffer J , da Gloria Carvalho M , Beall B . Front Microbiol 2018 9 3199 Streptococcus pneumoniae is a highly impactful bacterial pathogen on a global scale. The principal pneumococcal virulence factor and target of effective vaccines is its polysaccharide capsule, of which there are many structurally distinct forms. Here, we describe four distinct strains of three Mitis group commensal species (Streptococcus infantis, Streptococcus mitis, and Streptococcus oralis) recovered from upper respiratory tract specimens from adults in Kenya and the United States that were PCR-positive for the pneumococcal serotype 5 specific gene, wzy5. For each of the four strains, the 15 genes comprising the capsular polysaccharide biosynthetic gene cluster (cps5) shared the same order found in serotype 5 pneumococci, and each of the serotype 5-specific genes from the serotype 5 pneumococcal reference strain shared 76-99% sequence identity with the non-pneumococcal counterparts. Double-diffusion experiments demonstrated specific reactivity of the non-pneumococcal strains with pneumococcal serotype 5 typing sera. Antiserum raised against S. mitis strain KE67013 specifically reacted with serotype 5 pneumococci for a positive Quellung reaction and stimulated serotype 5 specific opsonophagocytic killing of pneumococci. Four additional commensal strains, identified using PCR serotyping assays on pharyngeal specimens, revealed loci highly homologous to those of pneumococci of serotypes 12F, 15A, 18C, and 33F. These data, in particular the species and strain diversity shown for serotype 5, highlight the existence of a broad non-pneumococcal species reservoir in the upper respiratory tract for the expression of capsular polysaccharides that are structurally related or identical to those corresponding to epidemiologically significant serotypes. Very little is known about the genetic and antigenic capsular diversity among the vast array of commensal streptococcal strains that represent multiple diverse species. The discovery of serotype 5 strains within three different commensal species suggests that extensive capsular serologic overlap exists between pneumococci and other members of the diverse Mitis group. These findings may have implications for our current understanding of naturally acquired immunity to S. pneumoniae and pneumococcal serotype distributions in different global regions. Further characterization of commensal strains carrying homologs of serotype-specific genes previously thought to be specific for pneumococci of known serotypes may shed light on the evolution of these important loci. |
Differential secretome profiling of a swine tracheal cell line infected with mycoplasmas of the swine respiratory tract
Leal Zimmer Fmda , Paludo GP , Moura H , Barr JR , Ferreira HB . J Proteomics 2018 192 147-159 Mycoplasma hyopneumoniae and Mycoplasma flocculare are genetically similar. However, M. hyopneumoniae causes porcine enzootic pneumonia, while M. flocculare is a commensal bacterium. M. hyopneumoniae and M. flocculare do not penetrate their host cells, and secreted proteins are important for bacterium-host interplay. Thus, the secretomes of a swine trachea cell line (NPTr) infected with M. hyopneumoniae 7448 (a pathogenic strain), M. hyopneumoniae J (a non-pathogenic strain) and M. flocculare were compared to shed light in bacterium-host interactions. Medium from the cultures was collected, and secreted proteins were identified by a LC-MS/MS. Overall numbers of identified host and bacterial proteins were, respectively, 488 and 58, for NPTr/M. hyopneumoniae 7448; 371 and 67, for NPTr/M. hyopneumoniae J; and 203 and 81, for NPTr/M. flocculare. The swine cells revealed different secretion profiles in response to the infection with each M. hyopneumoniae strain or with M. flocculare. DAMPs and extracellular proteasome proteins, secreted in response to cell injury and death, were secreted by NPTr cells infected with M. hyopneumoniae 7448. All three mycoplasmas secreted virulence factors during NPTr infection, but M. hyopneumoniae 7448 secreted higher number of adhesins and hypothetical proteins, that may be related with pathogenicity. SIGNIFICANCE: The enzootic pneumonia caused by mycoplasmas of swine respiratory tract has economic loss consequences in pig industry due to antibiotic costs and pig weight loss. However, some genetically similar mycoplasmas are pathogenic while others, such as Mycoplasma hyopneumoniae and Mycoplasma flocculare, are non-pathogenic. Here, we conducted an infection assay between swine cells and pathogenic and non-pathogenic mycoplasmas to decipher secreted proteins during host-pathogen interaction. Mycoplasma response to cell infection was also observed. Our study provided new insights on secretion profile of swine cells in response to the infection with pathogenic and non-pathogenic mycoplasmas. It was possible to observe that pathogenic M. hyopneumoniae 7448 secreted known virulence factors and swine cells responded by inducing cell death. Otherwise, M. hyopneumoniae J and M. flocculare, non-pathogenic mycoplasmas, secreted a different profile of virulence factors in response to swine cells. Consequently, swine cells altered their secretome profile, but the changes were not sufficient to cause disease. |
Comparative proteomics of two Mycoplasma hyopneumoniae strains and Mycoplasma flocculare identified potential porcine enzootic pneumonia determinants
Paes JA , Machado Ldpn , Dos Anjos Leal FM , de Moraes SN , Moura H , Barr JR , Ferreira HB . Virulence 2018 9 (1) 1230-1246 Mycoplasma hyopneumoniae and Mycoplasma flocculare are genetically similar bacteria, which coinhabit the porcine respiratory tract. These mycoplasmas share most of the known virulence factors, but, while M. hyopneumoniae causes porcine enzootic pneumonia (PEP), M. flocculare is a commensal species. To identify potential PEP determinants and provide novel insights on mycoplasma-host interactions, the whole cell proteomes of two M. hyopneumoniae strains, one pathogenic (7448) and other non-pathogenic (J), and M. flocculare were compared. A cell fractioning approach combined with LC-MS/MS proteomics was used to analyze cytoplasmic and surface-enriched protein fractions. Average detection of ~50% of the predicted proteomes of M. hyopneumoniae 7448 and J, and M. flocculare was achieved. Many of the identified proteins were differentially represented in M. hyopneumoniae 7448 in comparison to M. hyopneumoniae J and M. flocculare, including potential PEP determinants, such as adhesins, proteases, and redox-balancing proteins, among others. The LC-MS/MS data also provided experimental validation for several genes previously regarded as hypothetical for all analyzed mycoplasmas, including some coding for proteins bearing virulence-related functional domains. The comprehensive proteome profiling of two M. hyopneumoniae strains and M. flocculare provided tens of novel candidates to PEP determinants or virulence factors, beyond those classically described. |
Epidemiology and molecular characterization of Neisseria lactamica carried in 11-19 years old students in Salvador, Brazil.
Moura Arss , Kretz CB , Ferreira IE , Nunes Ampb , de Filippis I , de Moraes JC , Reis MG , McBride AJA , Wang X , Campos LC . Int J Med Microbiol 2018 308 (4) 454-458 Neisseria lactamica is a nonpathogenic commensal bacterium that is potentially associated with the development of natural immunity against N. meningitidis. However, the genetic variation present in natural populations of N. lactamica has not been fully investigated. To better understand its epidemiology and genetic variation, we studied N. lactamica carriage in 1200 students aged 11-19 years old in Salvador, Brazil. The carriage prevalence was 4.5% (54/1200), with no statistical difference among sex and age, although we observed a trend towards higher carriage prevalence among 11-year-old individuals. Whole genome sequence analysis revealed a high genetic diversity among the isolates, with the presence of 32 different STs, 28 (87.5%) of which were new. A total of 21/50 (42%) isolates belonged to three different clonal complexes. While none of the isolates contained nadA or fHpb alleles, we detected 21 FetA variants, 20 NhbA variants and two variants of PorB. The data provide detailed information on circulating N. lactamica isolates in adolescents in Brazil and are complementary to studies in other countries. |
Nasopharyngeal carriage of Streptococcus pneumoniae among HIV-infected and -uninfected children <5 years of age before introduction of pneumococcal conjugate vaccine in Mozambique
Verani JR , Massora S , Acacio S , Dos Santos RT , Vubil D , Pimenta F , Moura I , Whitney CG , Costa MH , Macete E , Matsinhe MB , Carvalho MDG , Sigauque B . PLoS One 2018 13 (2) e0191113 Nasopharyngeal carriage is a precursor for pneumococcal disease and can be useful for evaluating pneumococcal conjugate vaccine (PCV) impact. We studied pre-PCV pneumococcal carriage among HIV-infected and -uninfected children in Mozambique. Between October 2012 and March 2013, we enrolled HIV-infected children age <5 years presenting for routine care at seven HIV clinics in 3 sites, including Maputo (urban-south), Nampula (urban-north), and Manhica (rural-south). We also enrolled a random sample of HIV-uninfected children <5 years old from a demographic surveillance site in Manhica. A single nasopharyngeal swab was obtained and cultured following enrichment in Todd Hewitt broth with yeast extract and rabbit serum. Pneumococcal isolates were serotyped by Quellung reaction and multiplex polymerase chain reaction. Factors associated with pneumococcal carriage were examined using logistic regression. Overall pneumococcal carriage prevalence was 80.5% (585/727), with similar prevalences among HIV-infected (81.5%, 339/416) and HIV-uninfected (79.1%, 246/311) children, and across age strata. Among HIV-infected, after adjusting for recent antibiotic use and hospitalization, there was no significant association between study site and colonization: Maputo (74.8%, 92/123), Nampula (83.7%, 82/98), Manhica (84.6%, 165/195). Among HIV-uninfected, report of having been born to an HIV-infected mother was not associated with colonization. Among 601 pneumococcal isolates from 585 children, serotypes 19F (13.5%), 23F (13.1%), 6A (9.2%), 6B (6.2%) and 19A (5.2%) were most common. The proportion of serotypes included in the 10- and 13-valent vaccines was 44.9% and 61.7%, respectively, with no significant differences by HIV status or age group. Overall 36.9% (n = 268) of children were colonized with a PCV10 serotype and 49.7% (n = 361) with a PCV13 serotype. Pneumococcal carriage was common, with little variation by geographic region, age, or HIV status. PCV10 was introduced in April 2013; ongoing carriage studies will examine the benefits of PCV10 among HIV-infected and-uninfected children. |
Comparative proteomics of the larval and adult stages of the model cestode parasite Mesocestoides corti.
de Lima JC , Monteiro KM , Cabrera TNB , Paludo GP , Moura H , Barr JR , Zaha A , Ferreira HB . J Proteomics 2018 175 127-135 Mesocestoides corti is a widely used model for the study of cestode biology, and its transition from the larval tetrathyridium (TT) stage to the strobilated, adult worm (ST) stage can be induced and followed in vitro. Here, a proteomic approach was used to describe and compare M. corti TT and ST protein repertories. Overall, 571 proteins were identified, 238 proteins in TT samples and 333 proteins in ST samples. Among the identified proteins, 207 proteins were shared by TTs and STs, while 157 were stage-specific, being 31 exclusive from TTs, and 126 from STs. Functional annotation revealed fundamental metabolic differences between the TT and the ST stages. TTs perform functions related mainly to basic metabolism, responsible for growth and vegetative development by asexual reproduction. STs, in contrast, perform a wider range of functions, including macromolecule biosynthetic processes, gene expression and control pathways, which may be associated to its proglottization/segmentation, sexual differentiation and more complex physiology. Furthermore, the generated results provided an extensive list of cestode proteins of interest for functional studies in M. corti. Many of these proteins are novel candidate diagnostic antigens, and/or potential targets for the development of new and more effective antihelminthic drugs. BIOLOGICAL SIGNIFICANCE: Cestodiases are parasitic diseases with serious impact on human and animal health. Efforts to develop more effective strategies for diagnosis, treatment or control of cestodiases are impaired by the still limited knowledge on many aspects of cestode biology, including the complex developmental processes that occur in the life cycles of these parasites. Mesocestoides corti is a good experimental model to study the transition from the larval to the adult stage, called strobilation, which occur in typical cestode life-cycles. The performed proteomics approach provided large-scale identification and quantification of M. corti proteins. Many stage-specific or differentially expressed proteins were detected in the larval tetrathyridium (TT) stage and in the strobilated, adult worm (ST) stage. Functional comparative analyses of the described protein repertoires shed light on function and processes associated to specific features of both stages, such as less differentiation and asexual reproduction in TTs, and proglottization/segmentation and sexual differentiation in ST. Moreover, many of the identified stage-specific proteins are useful as cestode developmental markers, and are potential targets for development of novel diagnostic methods and therapeutic drugs for cestodiases. |
Surfaceome Analysis Protocol for the Identification of Novel Bordetella pertussis Antigens.
Williamson YM , Whitmon J , West-Deadwyler R , Moura H , Woolfitt AR , Rees J , Schieltz DM , Barr JR . Methods Mol Biol 2018 1722 3-20 The bacterial surfaceome, comprising outer membrane-sorted and/or associated (i.e., cell transporters), cell surface-exposed (i.e., adhesins) and extracellularly secreted proteins (i.e., toxins), has been characterized in bacterial pathogens, such as Bordetella pertussis (Bp) to provide information for use in development of diagnostic and prevention strategies. This protein subset has clinical significance, as these bacterial proteins are often associated with attachment to host cells, microbial pathogenesis and antibody-mediated immunity. Here we describe classical surface membrane protein enrichment techniques, followed by proteomic methodologies, such as gel-free protein separation and antibody-affinity capture technologies in combination with nano-liquid chromatography mass spectrometry, for the identification and characterization of Bp surfaceome proteins. |
Production and characterization of monoclonal antibodies against Encephalitozoon intestinalis and Encephalitozoon sp. spores and their developmental stages
Izquierdo F , Moura H , Bornay-Llinares FJ , Sriram R , Hurtado C , Magnet A , Fenoy S , Visvesvara G , Del Aguila C . Parasit Vectors 2017 10 (1) 560 BACKGROUND: Microsporidia are intracellular obligate parasites traditionally associated with immunosuppressed patients; their detection in immunocompetent patients has increased, highlighting their possible importance as emerging pathogens. Detection of spores in stools, urine, body fluids and tissues is difficult and immunological techniques such as immunofluorescence have proved to be a useful and reliable tool in the diagnosis of human microsporidiosis. For this reason, we have produced and characterized monoclonal antibodies (MAbs) specific for Encephalitozoon intestinalis (the second most frequent microsporidian infecting humans), and other Encephalitozoon species, that can be used in different diagnostic techniques. RESULTS: Seven MAbs were selected in accordance with their optical density (OD). Four (4C4, 2C2, 2E5 and 2H2) were isotype IgG2a; two (3A5 and 3C9) isotype IgG3, and one Mab, 1D7, IgM isotype. The selected monoclonal antibody-secreting hybridomas were characterized by indirect immunofluorescence antibody test (IFAT), enzyme-linked immunosorbent assay (ELISA), Western blot, immunoelectron microscopy (Immunogold) and in vitro cultures. The study by IFAT showed different behavior depending on the MAbs studied. The MAbs 4C4, 2C2, 2E5 and 2H2 showed reactivity against epitopes in the wall of the spore (exospore and endospore) epitopes located in Encephalitozoon sp. spores, whereas the MAbs 3A5, 1D7 and 3C9 showed reactivity against internal epitopes (cytoplasmic contents or sporoplasm) of E. intestinalis spores. All MAbs recognized the developing parasites in the in vitro cultures of E. intestinalis. Additionally, 59 formalin-fixed stool samples that had been previously analyzed were screened, with 26 (44%) presenting microsporidian spores (18 samples with E. intestinalis and 8 samples with Enterocytozoon bieneusi). Detection of microsporidian spores by microscopy was performed using Calcofluor stain, Modified Trichrome, Quick-Hot Gram Chromotrope, as well as IFAT using MAbs 4C4, 2C2, 2E5 and 2H2. The 4 MAbs tested clearly recognized the larger spores corresponding to E. intestinalis, but showed no reactivity with Enterocytozoon bieneusi spores. The mass spectrometry and proteomic study revealed that the Mabs 4C4, 2C2, 2E5 and 2H2 recognized the Spore Wall Protein 1 (SWP1) as the antigenic target. CONCLUSIONS: The IFAT-positive MAbs exhibited excellent reactivity against spores and developmental stages, permitting their use in human and animal diagnosis. The epitopes recognized (exospore, endospore and cytoplasmic contents) by the different MAbs developed need further study, and may reveal potential targets for vaccine development, immunotherapy and chemotherapy. |
Challenges and opportunities to scale up cardiovascular disease secondary prevention in Latin America and the Caribbean
Avezum A , Perel P , Oliveira GBF , Lopez-Jaramillo P , Restrepo G , Loustalot F , Srur A , de La Noval R , Connell KI , Cruz-Flores S , de Moura L , Castellac G , Mattos AC , Ordunez P . Glob Heart 2017 13 (2) 83-91 Cardiovascular disease (CVD) is the leading cause of death throughout the world; however, a reduction of 21% (age-standardized cardiovascular mortality rates per 100,000 inhabitants) was observed between 1990 and 2010, with more substantial reductions in CVD mortality evident in high-income countries (~42% reduction in CVD deaths) (Table 1) [1,2]. |
Molecular characterization of Neisseria meningitidis isolates recovered from 11-19-year-old meningococcal carriers in Salvador, Brazil.
Moura Arss , Kretz CB , Ferreira IE , Nunes Ampb , de Moraes JC , Reis MG , McBride AJA , Wang X , Campos LC . PLoS One 2017 12 (9) e0185038 Characterization of meningococci isolated from the pharynx is essential towards understanding the dynamics of meningococcal carriage and disease. Meningococcal isolates, collected from adolescents resident in Salvador, Brazil during 2014, were characterized by multilocus sequence typing, genotyping or whole-genome sequencing. Most were nongroupable (61.0%), followed by genogroups B (11.9%) and Y (8.5%). We identified 34 different sequence types (STs), eight were new STs, distributed among 14 clonal complexes (cc), cc1136 represented 20.3% of the nongroupable isolates. The porA and fetA genotypes included P1.18,25-37 (11.9%), P1.18-1,3 (10.2%); F5-5 (23.7%), F4-66 (16.9%) and F1-7 (13.6%). The porB class 3 protein and the fHbp subfamily A (variants 2 and 3) genotypes were found in 93.0 and 71.0% of the isolates, respectively. NHBA was present in all isolates, and while most lacked NadA (94.9%), we detected the hyperinvasive lineages B:P1.19,15:F5-1:ST-639 (cc32); C:P1.22,14-6:F3-9:ST-3780 (cc103) and W:P1.5,2:F1-1:ST-11 (cc11). This is the first report on the genetic diversity and vaccine antigen prevalence among N. meningitidis carriage isolates in the Northeast of Brazil. This study highlights the need for ongoing characterization of meningococcal isolates following the introduction of vaccines and for determining public health intervention strategies. |
Application of MALDI-TOF MS Systems in the Rapid Identification of Campylobacter spp. of Public Health Importance.
Hsieh YH , Wang YF , Moura H , Miranda N , Simpson S , Gowrishankar R , Barr J , Kerdahi K , Sulaiman IM . J AOAC Int 2017 101 (3) 761-768 Campylobacteriosis is an infectious gastrointestinal disease caused by Campylobacter spp.In most cases, it is either underdiagnosed or underreported due to poor diagnostics and limited databases. Several DNA-based molecular diagnostic techniques, including 16S ribosomal RNA (rRNA) sequence typing, have been widely used in the species identification of Campylobacter. Nevertheless, these assays are time-consuming and require a high quality of bacterial DNA. Matrix-assisted laser desorption ionization (MALDI) time-of-flight (TOF) MS is an emerging diagnostic technology that can provide the rapid identification of microorganisms by using their intact cells without extraction or purification. In this study, we analyzed 24 American Type Culture Collection reference isolates of 16 Campylobacter spp. and five unknown clinical bacterial isolates for rapid identification utilizing two commercially available MADI-TOF MS platforms, namely the bioMérieux VITEK® MS and Bruker Biotyper systems. In addition, 16S rRNA sequencing was performed to confirm the species-level identification of the unknown clinical isolates. Both MALDI-TOF MS systems identified the isolates of C. jejuni, C. coli, C. lari, and C. fetus. The results of this study suggest that the MALDI-TOF MS technique can be used in the identification of Campylobacter spp. of public health importance. |
Ribotypes associated with Clostridium difficile outbreaks in Brazil display distinct surface protein profiles.
Ferreira TG , Moura H , Barr JR , Pilotto Domingues RMC , Ferreira EO . Anaerobe 2017 45 120-128 Clostridium difficile is a spore-forming anaerobic intestinal pathogen that causes Clostridium difficile infection (CDI). C. difficile is the leading cause of toxin-mediated nosocomial antibiotic-associated diarrhea. The pathogenesis of CDI is attributed to two major virulence factors, TcdA and TcdB toxins, that cause the symptomatic infection. C. difficile also expresses a number of key proteins, including cell wall proteins (CWPs). S-layer proteins (SLPs) are CWPs that form a paracrystalline surface array that coats the surface of the bacterium. SLPs have a role in C. difficile binding to the gastrointestinal tract, but their importance in virulence need to be better elucidated. Here, we describe bottom-up proteomics analysis of surface-enriched proteins fractions obtained through glycine extraction of five C. difficile clinical isolates from Brazil using gel-based and gel-free approaches. We were able to identify approximately 250 proteins for each strain, among them SlpA, Cwp2, Cwp6, CwpV and Cwp84. Identified CWPs presented different amino acid coverage, which might suggest differences in post-translational modifications. Proteomic analysis of SLPs from ribotype 133, agent of C. difficile outbreaks in Brazil, revealed unique proteins and provided additional information towards in depth characterization of the strains causing CDI in Brazil. |
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