Last data update: Oct 28, 2024. (Total: 48004 publications since 2009)
Records 1-14 (of 14 Records) |
Query Trace: Roundtree A[original query] |
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Campylobacteriosis outbreak linked to municipal water, Nebraska, USA, 2021(1)
Jansen L , Birn R , Koirala S , Oppegard S , Loeck B , Hamik J , Wyckoff E , Spindola D , Dempsey S , Bartling A , Roundtree A , Kahler A , Lane C , Hogan N , Strockbine N , McKeel H , Yoder J , Mattioli M , Donahue M , Buss B . Emerg Infect Dis 2024 30 (10) 1998-2005 In September 2021, eight campylobacteriosis cases were identified in a town in Nebraska, USA. We assessed potential exposures for a case-control analysis. We conducted whole-genome sequencing on Campylobacter isolates from patients' stool specimens. We collected large-volume dead-end ultrafiltration water samples for Campylobacter and microbial source tracking testing at the Centers for Disease Control and Prevention. We identified 64 cases in 2 waves of illnesses. Untreated municipal tap water consumption was strongly associated with illness (wave 1 odds ratio 15.36; wave 2 odds ratio 16.11). Whole-genome sequencing of 12 isolates identified 2 distinct Campylobacter jejuni subtypes (1 subtype/wave). The town began water chlorination, after which water testing detected coliforms. One dead-end ultrafiltration sample yielded nonculturable Campylobacter and avian-specific fecal rRNA genomic material. Our investigation implicated contaminated, untreated, municipal water as the source. Results of microbial source tracking supported mitigation with continued water chlorination. No further campylobacteriosis cases attributable to water were reported. |
Shiga toxin-producing Escherichia coli o157:H7 illness outbreak associated with untreated, pressurized, municipal irrigation water - Utah, 2023
Osborn B , Hatfield J , Lanier W , Wagner J , Oakeson K , Casey R , Bullough J , Kache P , Miko S , Kunz J , Pederson G , Leeper M , Strockbine N , McKeel H , Hofstetter J , Roundtree A , Kahler A , Mattioli M . MMWR Morb Mortal Wkly Rep 2024 73 (18) 411-416 During July-September 2023, an outbreak of Shiga toxin-producing Escherichia coli O157:H7 illness among children in city A, Utah, caused 13 confirmed illnesses; seven patients were hospitalized, including two with hemolytic uremic syndrome. Local, state, and federal public health partners investigating the outbreak linked the illnesses to untreated, pressurized, municipal irrigation water (UPMIW) exposure in city A; 12 of 13 ill children reported playing in or drinking UPMIW. Clinical isolates were genetically highly related to one another and to environmental isolates from multiple locations within city A's UPMIW system. Microbial source tracking, a method to indicate possible contamination sources, identified birds and ruminants as potential sources of fecal contamination of UPMIW. Public health and city A officials issued multiple press releases regarding the outbreak reminding residents that UPMIW is not intended for drinking or recreation. Public education and UPMIW management and operations interventions, including assessing and mitigating potential contamination sources, covering UPMIW sources and reservoirs, indicating UPMIW lines and spigots with a designated color, and providing conspicuous signage to communicate risk and intended use might help prevent future UPMIW-associated illnesses. |
Notes from the field: Gastrointestinal illness among hikers on the Pacific Crest Trail - Washington, August-October 2022
Hamlet A , Begley K , Miko S , Stewart L , Tellier W , Gonzalez-De Leon J , Booth H , Lippman S , Kahler A , Roundtree A , Hatada A , Lindquist S , Melius B , Goldoft M , Mattioli M , Holshue M . MMWR Morb Mortal Wkly Rep 2023 72 (36) 997-998 On August 26, 2022, the Washington State Department of Health received informal reports of numerous Pacific Crest Trail hikers with acute gastroenteritis (AGE). The Pacific Crest Trail stretches 2,650 miles from California to Washington, attracting hikers from around the world (1). An investigation of social media postings on September 5 found 27 reports of AGE by Washington Pacific Crest Trail hikers during the previous month, 26 of whom provided information about symptom onset date (Figure). Numerous additional reports without a specific date were found, suggesting that that AGE was occurring during the 2022 hiking season |
Case of primary amebic meningoencephalitis associated with surfing at an artificial surf venue: Environmental investigation
Miko S , Cope JR , Hlavsa MC , Ali IKM , Brown TW , Collins JP , Greeley RD , Kahler AM , Moore KO , Roundtree AV , Roy S , Sanders LL , Shah V , Stuteville HD , Mattioli MC . ACS ES T Water 2022 Naegleria fowleri is a thermophilic ameba found in freshwater that causes primary amebic meningoencephalitis (PAM) when it enters the nose and migrates to the brain. In September 2018, a 29-year-old man died of PAM after traveling to Texas. We conducted an epidemiologic and environmental investigation to identify the water exposure associated with this PAM case. The patients most probable water exposure occurred while surfing in an artificial surf venue. The surf venue water was not filtered or recirculated; water disinfection and water quality testing were not documented. N. fowleri and thermophilic amebae were detected in recreational water and sediment samples throughout the facility. Codes and standards for treated recreational water venues open to the public could be developed to address these novel venues. Clinicians and public health officials should also consider novel recreational water venues as a potential exposure for this rare amebic infection. Not subject to U.S. Copyright. Published 2023 by American Chemical Society. |
Fecal indicators and antibiotic resistance genes exhibit diurnal trends in the Chattahoochee River: Implications for water quality monitoring.
Nguyen KH , Smith S , Roundtree A , Feistel DJ , Kirby AE , Levy K , Mattioli MC . Front Microbiol 2022 13 1029176 Water bodies that serve as sources of drinking or recreational water are routinely monitored for fecal indicator bacteria (FIB) by state and local agencies. Exceedances of monitoring thresholds set by those agencies signal likely elevated human health risk from exposure, but FIB give little information about the potential source of contamination. To improve our understanding of how within-day variation could impact monitoring data interpretation, we conducted a study at two sites along the Chattahoochee River that varied in their recreational usage and adjacent land-use (natural versus urban), collecting samples every 30 min over one 24-h period. We assayed for three types of microbial indicators: FIB (total coliforms and Escherichia coli); human fecal-associated microbial source tracking (MST) markers (crAssphage and HF183/BacR287); and a suite of clinically relevant antibiotic resistance genes (ARGs; blaCTX-M, blaCMY, MCR, KPC, VIM, NDM) and a gene associated with antibiotic resistance (intl1). Mean levels of FIB and clinically relevant ARGs (blaCMY and KPC) were similar across sites, while MST markers and intI1 occurred at higher mean levels at the natural site. The human-associated MST markers positively correlated with antibiotic resistant-associated genes at both sites, but no consistent associations were detected between culturable FIB and any molecular markers. For all microbial indicators, generalized additive mixed models were used to examine diurnal variability and whether this variability was associated with environmental factors (water temperature, turbidity, pH, and sunlight). We found that FIB peaked during morning and early afternoon hours and were not associated with environmental factors. With the exception of HF183/BacR287 at the urban site, molecular MST markers and intI1 exhibited diurnal variability, and water temperature, pH, and turbidity were significantly associated with this variability. For blaCMY and KPC, diurnal variability was present but was not correlated with environmental factors. These results suggest that differences in land use (natural or urban) both adjacent and upstream may impact overall levels of microbial contamination. Monitoring agencies should consider matching sample collection times with peak levels of target microbial indicators, which would be in the morning or early afternoon for the fecal associated indicators. Measuring multiple microbial indicators can lead to clearer interpretations of human health risk associated with exposure to contaminated water. |
Interlaboratory performance and quantitative PCR data acceptance metrics for NIST SRM 2917
Sivaganesan M , Willis JR , Karim M , Babatola A , Catoe D , Boehm AB , Wilder M , Green H , Lobos A , Harwood VJ , Hertel S , Klepikow R , Howard MF , Laksanalamai P , Roundtree A , Mattioli M , Eytcheson S , Molina M , Lane M , Rediske R , Ronan A , D'Souza N , Rose JB , Shrestha A , Hoar C , Silverman AI , Faulkner W , Wickman K , Kralj JG , Servetas SL , Hunter ME , Jackson SA , Shanks OC . Water Res 2022 225 119162 Surface water quality quantitative polymerase chain reaction (qPCR) technologies are expanding from a subject of research to routine environmental and public health laboratory testing. Readily available, reliable reference material is needed to interpret qPCR measurements, particularly across laboratories. Standard Reference Material® 2917 (NIST SRM® 2917) is a DNA plasmid construct that functions with multiple water quality qPCR assays allowing for estimation of total fecal pollution and identification of key fecal sources. This study investigates SRM 2917 interlaboratory performance based on repeated measures of 12 qPCR assays by 14 laboratories (n = 1008 instrument runs). Using a Bayesian approach, single-instrument run data are combined to generate assay-specific global calibration models allowing for characterization of within- and between-lab variability. Comparable data sets generated by two additional laboratories are used to assess new SRM 2917 data acceptance metrics. SRM 2917 allows for reproducible single-instrument run calibration models across laboratories, regardless of qPCR assay. In addition, global models offer multiple data acceptance metric options that future users can employ to minimize variability, improve comparability of data across laboratories, and increase confidence in qPCR measurements. |
Notes from the Field: An Outbreak of Escherichia coli O157:H7 Infections Linked to Romaine Lettuce Exposure - United States, 2019
Hoff C , Higa J , Patel K , Gee E , Wellman A , Vidanes J , Holland A , Kozyreva V , Zhu J , Mattioli M , Roundtree A , McFadden K , Whitlock L , Wise M , Gieraltowski L , Schwensohn C . MMWR Morb Mortal Wkly Rep 2021 70 (18) 689-690 On September 16, 2019, PulseNet, the national molecular subtyping network for foodborne disease surveillance, reported a multistate cluster of seven Escherichia coli O157:H7 infections from California (five), Oregon (one), and Pennsylvania (one). Isolates from cases of human illness were sequenced and then analyzed using core-genome multilocus sequence typing (cgMLST); the isolates were closely related within three allele differences (1). Federal, state, and local officials initiated a multistate outbreak investigation to identify the source and prevent additional illnesses. |
Non-pneumococcal mitis-group streptococci confound detection of pneumococcal capsular serotype-specific loci in upper respiratory tract
Carvalho Mda G , Pimenta FC , Moura I , Roundtree A , Gertz RE Jr , Li Z , Jagero G , Bigogo G , Junghae M , Conklin L , Feikin DR , Breiman RF , Whitney CG , Beall BW . PeerJ 2013 1 e97 We performed culture-based and PCR-based tests for pneumococcal identification and serotyping from carriage specimens collected in rural and urban Kenya. Nasopharyngeal specimens from 237 healthy children <5 years old (C-NPs) and combined nasopharyngeal/oropharyngeal specimens from 158 adults (A-NP/OPs, 118 HIV-positive) were assessed using pneumococcal isolation (following broth culture enrichment) with Quellung-based serotyping, real-time lytA-PCR, and conventional multiplexed PCR-serotyping (cmPCR). Culture-based testing from C-NPs, HIV-positive A-NP/OPs, and HIV-negative A-NP/OPs revealed 85.2%, 40.7%, and 12.5% pneumococcal carriage, respectively. In contrast, cmPCR serotypes were found in 93.2%, 98.3%, and 95.0% of these sets, respectively. Two of 16 lytA-negative C-NPs and 26 of 28 lytA-negative A-NP/OPs were cmPCR-positive for 1-10 serotypes (sts) or serogroups (sgs). A-NP/OPs averaged 5.5 cmPCR serotypes/serogroups (5.2 in HIV-positive, 7.1 in HIV-negative) and C-NPs averaged 1.5 cmPCR serotypes/serogroups. cmPCR serotypes/serogroups from lytA-negative A-NP/OPs included st2, st4, sg7F/7A, sg9N/9L, st10A, sg10F/10C/33C, st13, st17F, sg18C/18A/18B/18F, sg22F/22A, and st39. Nine strains of three non-pneumococcal species (S. oralis, S. mitis, and S. parasanguinis) (7 from A-OP, 1 from both A-NP and A-OP, and 1 from C-NP) were each cmPCR-positive for one of 7 serotypes/serogroups (st5, st13, sg15A/15F, sg10F/10C/33C, sg33F/33A/37, sg18C/18A/18B/18F, sg12F/12A/12B/ 44/46) with amplicons revealing 83.6-99.7% sequence identity to pneumococcal references. In total, 150 cmPCR amplicons from carriage specimens were sequenced, including 25 from lytA-negative specimens. Amplicon sequences derived from specimens yielding a pneumococcal isolate with the corresponding serotype were identical or highly conserved (>98.7%) with the reference cmPCR amplicon for the st, while cmPCR amplicons from lytA-negative specimens were generally more divergent. Separate testing of 56 A-OPs and 56 A-NPs revealed that approximately 94% of the positive cmPCR results from A-NP/OPs were from OP microbiota. In contrast, A-NPs yielded >2-fold more pneumococcal isolates than A-OPs. Verified and suspected non-pneumococcal cmPCR serotypes/serogroups appeared to be relatively rare in C-NPs and A-NPs compared to A-OPs. Our findings indicate that non-pneumococcal species can confound serotype-specific PCR and other sequence-based assays due to evolutionarily conserved genes most likely involved in biosynthesis of surface polysaccharide structures. |
Sequential triplex real-time PCR assay for detecting 21 pneumococcal capsular serotypes that account for a high global disease burden.
Pimenta FC , Roundtree A , Soysal A , Bakir M , du Plessis M , Wolter N , von Gottberg A , McGee L , Carvalho MG , Beall B . J Clin Microbiol 2012 51 (2) 647-52 We developed and validated a real-time PCR assay consisting of 7 triplexed reactions to identify 11 individual serotypes plus 10 small serogroups representing the majority of disease-causing isolates of Streptococcus pneumoniae. This assay targets the 13 serotypes included within the 13-valent conjugate vaccine and 8 additional key serotypes or serogroups. Advantages over other serotyping assays are described. The assay will be expanded to 40 serotypes/serogroups. We will provide periodic updates at our protocol web site. |
Potential non-pneumococcal confounding of PCR-based determination of serotype in carriage
Carvalho MD , Jagero G , Bigogo GM , Junghae M , Pimenta FC , Moura I , Roundtree A , Li Z , Conklin L , Feikin DR , Breiman RF , Whitney CG , Beall B . J Clin Microbiol 2012 50 (9) 3146-7 Monitoring pneumococcal carriage serotype distributions is increasingly used to study pneumococcal biology, disease epidemiology, and vaccine impact.... |
Molecular epidemiological investigation to determine the source of a fatal case of serotype 22F pneumococcal meningitis.
Lamaro-Cardoso J , de Lemos AP , Carvalho Mda G , Pimenta FC , Roundtree A , Motta L , Vieira MA , Sgambatti S , Thorn LK , Pessoa-Junior V , Minamisava R , Harrison LH , Beall BW , Brandileone MC , Andrade AL . J Med Microbiol 2012 61 686-92 A child's death due to pneumococcal meningitis after contracting the disease in an after-school programme prompted an investigation to assess nasopharyngeal (NP) carriage among her contacts. The serotype of the meningitis case isolate was determined, together with the serotypes of the NP specimens of contacts, comprising the case patient's brother, the case patient's after-school programme contacts and the brother's day-care centre (DCC) contacts. NP swabs from 155 children and 69 adults were obtained. Real-time PCR and conventional multiplex PCR (CM-PCR) assays were used to detect pneumococcal carriage and determine serotypes. Broth-enriched culture of NP specimens followed by pneumococcal isolation and Quellung-based serotyping were also performed. DNA extracts prepared from cerebrospinal fluid of the index case and from the NP strain isolated from the brother and from one attendee of the brother's DCC were subjected to genotyping. Pneumococcal carriage assessed by real-time PCR and culture was 49.6 and 36.6 %, respectively (P<0.05). Twenty-three serotypes were detected using CM-PCR, with serotypes 6A/6B, 14, 19F, 6C/6D, 22F/22A, 23F and 11A/11D being the most frequent. All eight serotype 22F/22A NP specimens recovered were from children attending the brother's DCC. The meningitis case isolate and the NP carriage isolate from the patient's brother were both serotype 22F and shared the same new multilocus sequence type (ST6403) with the attendee of the brother's DCC. CM-PCR proved to be useful for assessing carriage serotype distribution in a setting of high-risk pneumococcal transmission. The causal serotype appeared to be linked to the brother of the case patient and attendees of his DCC. |
Pre- and post-conjugate vaccine epidemiology of pneumococcal serotype 6C invasive disease and carriage within Navajo and White Mountain Apache communities
Millar EV , Pimenta FC , Roundtree A , Jackson D , Carvalho MD , Perilla MJ , Reid R , Santosham M , Whitney CG , Beall BW , O'Brien KL . Clin Infect Dis 2010 51 (11) 1258-65 BACKGROUND: A second-generation 13-valent pneumococcal conjugate vaccine, PCV13, was recently licensed. Although PCV13 includes serotype 6A, the usefulness of that antigen may be limited by the emergence of a new serotype, 6C, which was identified among isolates initially characterized (Quellung reaction) as serotype 6A. The epidemiology of serotype 6C prior to and after 7-valent PCV (PCV7) introduction is incompletely understood. METHODS: We analyzed conventionally serotyped 6A (CS6A) pneumococci from invasive disease case patients of all ages and carriage isolates from children and adults obtained in population-based studies among Navajo and White Mountain Apache communities during 1994-2009. Samples were tested by triplex polymerase chain reaction to resolve serotypes 6C and 6A. RESULTS: A total of 74 invasive CS6A episodes occurred. All were retyped by polymerase chain reaction; 40 (54.1%) were serotype 6C. The mean annual incidence of serotype 6C invasive disease was 0.3 (95% confidence interval, 0.03-0.9), 0.7 (95% confidence interval, 0.2-1.3), and 1.5 (95% confidence interval, 1.0-2.1) cases per 100,000 population in the years prior to the PCV7 efficacy trial, during the time the PCV7 trial was conducted, and following PCV7 introduction and routine use, respectively ([Formula: see text]). In the routine vaccination era, 76% of invasive CS6As were serotype 6C; nearly all cases occurred in adults. The proportion of serotype 6C among CS6A carriage isolates increased from 42% to 61% to 94% in the prevaccine, early vaccine, and routine vaccination eras, respectively. CONCLUSION: In the PCV7 routine use era, virtually all serogroup 6 invasive pneumococcal disease and carriage strains among Navajo and White Mountain Apache communities are 6C. Monitoring and evaluation of this and other emerging serotypes among invasive disease and carriage isolates is warranted. |
Revisiting pneumococcal carriage using broth-enrichment and PCR techniques for enhanced detection of carriage and serotypes
Carvalho MD , Pimenta FC , Jackson D , Roundtree A , Ahmad Y , Millar EV , O'Brien KL , Whitney CG , Cohen AL , Beall BW . J Clin Microbiol 2010 48 (5) 1611-8 The measurement of pneumococcal carriage in the nasopharyngeal reservoir is subject to potential confounders that include low-density and multiple-strain colonization. To compare different methodologies, we picked a random sampling of 100 nasopharyngeal (NP) specimens recovered from infants less than 2 years of age that were previously assessed for pneumococcal carriage and serotypes using a conventional method employing direct plating from the transport/storage medium (50 pneumococcal culture-negative and 50 pneumococcal culture-positive). We used a broth enrichment approach and a conventional PCR approach (with and without broth-enrichment) for determining pneumococcal carriage and serotypes to compare to initial conventional culture-based results. Additionally we used lytA-targeted real time PCR for pneumococcal detection. Broth enrichment for both culture-based and PCR based methods enhanced the isolation of pneumococci and detection of serotype diversity, with the most effective serotype-deduction method employing broth enrichment prior to sequential multiplex PCR. Similarly, we also found that broth enrichment followed by lytA-specific real time PCR was most sensitive for detecting apparent pneumococcal carriage. The broth enrichment, conventional multiplex PCR, and real time PCR approaches used in this study were effective in detecting pneumococcal carriage within the 50 specimens that were negative using conventional direct plating from transport medium (ranging from 8/50 - 22/50 (16-44%) positives), and the 3 different serotyping approaches employing broth-enrichment increased the number of serotype identifications from the 100 specimens (12 - 29 additional identifications). A PCR-based approach that employed a broth enrichment step appeared to best enhance the detection of mixed serotypes and low density pneumococcal carriage. |
Rarely occurring 19A-like cps locus from a serotype 19F pneumococcal isolate indicates continued need of serology-based quality control for PCR-based serotype determinations
Pimenta FC , Gertz RE Jr , Roundtree A , Yu J , Nahm MH , McDonald RR , Carvalho Mda G , Beall BW . J Clin Microbiol 2009 47 (7) 2353-4 Determination of the DNA sequences corresponding to all 91 pneumococcal capsular biosynthetic (cps) loci (1, 3, 6, 9) has allowed serotype determinations from pneumococcal isolates and clinical specimens using conventional PCR assays (2, 4, 7, 8, 10). We developed sequential, multiplexed PCR schemes that resolve 33 serologic specificities, including 20 serotypes and 13 serotype subsets (4, 7, 8). We recently expanded the scheme to 40 specificities (www.cdc.gov/ncidod/biotech/strep/pcr.htm). | PCR primers targeted serotype-specific open reading frames within central portions of known cps loci (4, 7, 8). Subsequent information (1, 3, 6) revealed that we primarily targeted serotype-specific oligosaccharide repeat unit polymerases (wzy encoded), glycosyl transferases, and flippases (wzx encoded). Our serotype 19A primers, however, targeted the mnaA gene that encodes UDP-N-acetylglucosamine-2-epimerase (8). Although the mnaA sequence differs markedly among the 15 cps loci that harbor it (serotypes 19A, -B, -C, -F; 12A, -B, -F; 9A, -N, -L, -V; 4; 36; 44; 46), due to potential exchanges of heterologous mnaA genes, we recently changed the 19A PCR assay to target wzy (our unpublished data). The wzy19A and wzy19F genes putatively provide the basis of the structural difference between the related 19A and 19F capsules (1). |
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