Last data update: May 06, 2024. (Total: 46732 publications since 2009)
Records 1-26 (of 26 Records) |
Query Trace: McKee C[original query] |
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Evaluation of the US COVID-19 Scenario Modeling Hub for informing pandemic response under uncertainty
Howerton E , Contamin L , Mullany LC , Qin M , Reich NG , Bents S , Borchering RK , Jung SM , Loo SL , Smith CP , Levander J , Kerr J , Espino J , van Panhuis WG , Hochheiser H , Galanti M , Yamana T , Pei S , Shaman J , Rainwater-Lovett K , Kinsey M , Tallaksen K , Wilson S , Shin L , Lemaitre JC , Kaminsky J , Hulse JD , Lee EC , McKee CD , Hill A , Karlen D , Chinazzi M , Davis JT , Mu K , Xiong X , Pastore YPiontti A , Vespignani A , Rosenstrom ET , Ivy JS , Mayorga ME , Swann JL , España G , Cavany S , Moore S , Perkins A , Hladish T , Pillai A , Ben Toh K , Longini I Jr , Chen S , Paul R , Janies D , Thill JC , Bouchnita A , Bi K , Lachmann M , Fox SJ , Meyers LA , Srivastava A , Porebski P , Venkatramanan S , Adiga A , Lewis B , Klahn B , Outten J , Hurt B , Chen J , Mortveit H , Wilson A , Marathe M , Hoops S , Bhattacharya P , Machi D , Cadwell BL , Healy JM , Slayton RB , Johansson MA , Biggerstaff M , Truelove S , Runge MC , Shea K , Viboud C , Lessler J . Nat Commun 2023 14 (1) 7260 Our ability to forecast epidemics far into the future is constrained by the many complexities of disease systems. Realistic longer-term projections may, however, be possible under well-defined scenarios that specify the future state of critical epidemic drivers. Since December 2020, the U.S. COVID-19 Scenario Modeling Hub (SMH) has convened multiple modeling teams to make months ahead projections of SARS-CoV-2 burden, totaling nearly 1.8 million national and state-level projections. Here, we find SMH performance varied widely as a function of both scenario validity and model calibration. We show scenarios remained close to reality for 22 weeks on average before the arrival of unanticipated SARS-CoV-2 variants invalidated key assumptions. An ensemble of participating models that preserved variation between models (using the linear opinion pool method) was consistently more reliable than any single model in periods of valid scenario assumptions, while projection interval coverage was near target levels. SMH projections were used to guide pandemic response, illustrating the value of collaborative hubs for longer-term scenario projections. |
Bats are key hosts in the radiation of mammal-associated Bartonella bacteria (preprint)
McKee CD , Bai Y , Webb CT , Kosoy MY . bioRxiv 2020 2020.04.03.024521 Bats are notorious reservoirs of several zoonotic diseases and may be uniquely tolerant of infection among mammals. Broad sampling has revealed the importance of bats in the diversification and spread of viruses and eukaryotes to other animal hosts. Vector-borne bacteria of the genus Bartonella are prevalent and diverse in mammals globally and recent surveys have revealed numerous Bartonella lineages in bats. We assembled a sequence database of Bartonella strains, consisting of nine genetic loci from 209 previously characterized lineages and 121 new cultured strains from bats, and used these data to perform the most comprehensive phylogenetic analysis of Bartonella to date. This analysis included estimation of divergence dates using a molecular clock and ancestral reconstruction of host associations and geography. We estimate that Bartonella began infecting mammals 62 million years ago near the Cretaceous-Paleogene boundary. Additionally, the radiation of particular Bartonella clades correlate strongly to the timing of diversification and biogeography of mammalian hosts. Bats were inferred to be the ancestral hosts of all mammal-associated Bartonella and appear to be responsible for the early geographic expansion of the genus. We conclude that bats have had a deep influence on the evolutionary radiation of Bartonella bacteria and their spread to other mammalian orders. These results support a ‘bat seeding’ hypothesis that could explain similar evolutionary patterns in other mammalian parasite taxa. Application of such phylogenetic tools as we have used to other taxa may reveal the general importance of bats in the ancient diversification of mammalian parasites.Significance statement Discovering the evolutionary history of infectious agents in animals is important for understanding the process of host adaptation and the origins of human diseases. To clarify the evolution of the Bartonella genus, which contains important human pathogens, we performed phylogenetic analysis on a broad diversity of Bartonella strains, including novel strains from bats. Our results indicate that Bartonella clades diversified along with their mammal hosts over millions of years. Bats appear to be especially important in the early radiation and geographic dispersal of Bartonella lineages. These patterns are consistent with research indicating a chiropteran origin of important human viruses and eukaryotic parasites, suggesting that bats may play a unique role as historical sources of infections to other hosts. |
Adapterama II: Universal amplicon sequencing on Illumina platforms (TaggiMatrix) (preprint)
Glenn TC , Pierson TW , Bayona-Vásquez NJ , Kieran TJ , Hoffberg SL , Thomas IV JC , Lefever DE , Finger JW , Gao B , Bian X , Louha S , Kolli RT , Bentley KE , Rushmore J , Wong K , Shaw TI , Rothrock MJ Jr , McKee AM , Guo TL , Mauricio R , Molina M , Cummings BS , Lash LH , Lu K , Gilbert GS , Hubbell SP , Faircloth BC . bioRxiv 2019 619544 Next-generation sequencing (NGS) of amplicons is used in a wide variety of contexts. Most NGS amplicon sequencing remains overly expensive and inflexible, with library preparation strategies relying upon the fusion of locus-specific primers to full-length adapter sequences with a single identifying sequence or ligating adapters onto PCR products. In Adapterama I, we presented universal stubs and primers to produce thousands of unique index combinations and a modifiable system for incorporating them into Illumina libraries. Here, we describe multiple ways to use the Adapterama system and other approaches for amplicon sequencing on Illumina instruments. In the variant we use most frequently for large-scale projects, we fuse partial adapter sequences (TruSeq or Nextera) onto the 5’ end of locus-specific PCR primers with variable-length tag sequences between the adapter and locus-specific sequences. These fusion primers can be used combinatorially to amplify samples within a 96-well plate (eight forward primers + 12 reverse primers yield 8 × 12 = 96 combinations), and the resulting amplicons can be pooled. The initial PCR products then serve as template for a second round of PCR with dual-indexed iTru or iNext primers (also used combinatorially) to make full-length libraries. The resulting quadruple-indexed amplicons have diversity at most base positions and can be pooled with any standard Illumina library for sequencing. The number of sequencing reads from the amplicon pools can be adjusted, facilitating deep sequencing when required or reducing sequencing costs per sample to an economically trivial amount when deep coverage is not needed. We demonstrate the utility and versatility of our approaches with results from six projects using different implementations of our protocols. Thus, we show that these methods facilitate amplicon library construction for Illumina instruments at reduced cost with increased flexibility. A simple web page to design fusion primers compatible with iTru primers is available at: http://baddna.uga.edu/tools-taggi.html. A fast and easy to use program to demultiplex amplicon pools with internal indexes is available at: https://github.com/lefeverde/Mr_Demuxy. |
Adapterama II: universal amplicon sequencing on Illumina platforms (TaggiMatrix).
Glenn TC , Pierson TW , Bayona-Vásquez NJ , Kieran TJ , Hoffberg SL , Thomas Iv JC , Lefever DE , Finger JW , Gao B , Bian X , Louha S , Kolli RT , Bentley KE , Rushmore J , Wong K , Shaw TI , Rothrock MJ Jr , McKee AM , Guo TL , Mauricio R , Molina M , Cummings BS , Lash LH , Lu K , Gilbert GS , Hubbell SP , Faircloth BC . PeerJ 2019 7 e7786 Next-generation sequencing (NGS) of amplicons is used in a wide variety of contexts. In many cases, NGS amplicon sequencing remains overly expensive and inflexible, with library preparation strategies relying upon the fusion of locus-specific primers to full-length adapter sequences with a single identifying sequence or ligating adapters onto PCR products. In Adapterama I, we presented universal stubs and primers to produce thousands of unique index combinations and a modifiable system for incorporating them into Illumina libraries. Here, we describe multiple ways to use the Adapterama system and other approaches for amplicon sequencing on Illumina instruments. In the variant we use most frequently for large-scale projects, we fuse partial adapter sequences (TruSeq or Nextera) onto the 5' end of locus-specific PCR primers with variable-length tag sequences between the adapter and locus-specific sequences. These fusion primers can be used combinatorially to amplify samples within a 96-well plate (8 forward primers + 12 reverse primers yield 8 × 12 = 96 combinations), and the resulting amplicons can be pooled. The initial PCR products then serve as template for a second round of PCR with dual-indexed iTru or iNext primers (also used combinatorially) to make full-length libraries. The resulting quadruple-indexed amplicons have diversity at most base positions and can be pooled with any standard Illumina library for sequencing. The number of sequencing reads from the amplicon pools can be adjusted, facilitating deep sequencing when required or reducing sequencing costs per sample to an economically trivial amount when deep coverage is not needed. We demonstrate the utility and versatility of our approaches with results from six projects using different implementations of our protocols. Thus, we show that these methods facilitate amplicon library construction for Illumina instruments at reduced cost with increased flexibility. A simple web page to design fusion primers compatible with iTru primers is available at: http://baddna.uga.edu/tools-taggi.html. A fast and easy to use program to demultiplex amplicon pools with internal indexes is available at: https://github.com/lefeverde/Mr_Demuxy. |
Molecular characterization of a novel relapsing fever Borrelia species from the desert cottontail (Sylvilagus audubonii) in New Mexico, USA.
Goodrich I , McKee C , Margos G , Kosoy M . J Wildl Dis 2022 58 (3) 646-651 The Borrelia genus comprises vector-borne, spirochete bacteria infecting vertebrates worldwide. We characterized a novel relapsing fever Borrelia species from a desert cottontail (Syvilagus audubonii) from New Mexico, United States, using an established multilocus sequence analysis approach. Phylogenetic analysis of the flagellin gene (flaB) and four other protein-coding loci (clpX, pepX, recG, rplB) grouped the novel Borrelia species with hard tick relapsing fever borreliae Borrelia lonestari, Borrelia theileri, and Borrelia miyamotoi. The identity of the vectors and other vertebrate hosts, geographic distribution, and zoonotic potential of this novel Borrelia species deserve further investigation. |
Bats are key hosts in the radiation of mammal-associated Bartonella bacteria.
McKee CD , Bai Y , Webb CT , Kosoy MY . Infect Genet Evol 2021 89 104719 Bats are notorious reservoirs of several zoonotic diseases and may be uniquely tolerant of infection among mammals. Broad sampling has revealed the importance of bats in the diversification and spread of viruses and eukaryotes to other animal hosts. Vector-borne bacteria of the genus Bartonella are prevalent and diverse in mammals globally and recent surveys have revealed numerous Bartonella lineages in bats. We assembled a sequence database of Bartonella strains, consisting of nine genetic loci from 209 previously characterized Bartonella lineages and 121 new cultured isolates from bats, and used these data to perform a comprehensive phylogenetic analysis of the Bartonella genus. This analysis included estimation of divergence dates using a molecular clock and ancestral reconstruction of host associations and geography. We estimate that Bartonella began infecting mammals 62 million years ago near the Cretaceous-Paleogene boundary. Additionally, the radiation of particular Bartonella clades correlate strongly to the timing of diversification and biogeography of mammalian hosts. Bats were inferred to be the ancestral hosts of all mammal-associated Bartonella and appear to be responsible for the early geographic expansion of the genus. We conclude that bats have had a deep influence on the evolutionary radiation of Bartonella bacteria and their spread to other mammalian orders. These results support a 'bat seeding' hypothesis that could explain similar evolutionary patterns in other mammalian parasite taxa. Application of such phylogenetic tools as we have used to other taxa may reveal the general importance of bats in the ancient diversification of mammalian parasites. |
Trypanosoma (Herpetosoma) diversity in rodents and lagomorphs of New Mexico with a focus on epizootological aspects of infection in Southern Plains woodrats (Neotoma micropus).
Goodrich I , McKee C , Kosoy M . PLoS One 2020 15 (12) e0244803 Protozoan parasites of the genus Trypanosoma infect a broad diversity of vertebrates and several species cause significant illness in humans. However, understanding of the phylogenetic diversity, host associations, and infection dynamics of Trypanosoma species in naturally infected animals is incomplete. This study investigated the presence of Trypanosoma spp. in wild rodents and lagomorphs in northern New Mexico, United States, as well as phylogenetic relationships among these parasites. A total of 458 samples from 13 rodent and one lagomorph species collected between November 2002 and July 2004 were tested by nested PCR targeting the 18S ribosomal RNA gene (18S rRNA). Trypanosoma DNA was detected in 25.1% of all samples, with the highest rates of 50% in Sylvilagus audubonii, 33.1% in Neotoma micropus, and 32% in Peromyscus leucopus. Phylogenetic analysis of Trypanosoma sequences revealed five haplotypes within the subgenus Herpetosoma (T. lewisi clade). Focused analysis on the large number of samples from N. micropus showed that Trypanosoma infection varied by age class and that the same Trypanosoma haplotype could be detected in recaptured individuals over multiple months. This is the first report of Trypanosoma infections in Dipodomys ordii and Otospermophilus variegatus, and the first detection of a haplotype phylogenetically related to T. nabiasi in North America in S. audubonii. This study lends important new insight into the diversity of Trypanosoma species, their geographic ranges and host associations, and the dynamics of infection in natural populations. |
Bartonella species in medically important mosquitoes, Central Europe.
Rudolf I , Blazejova H , Mendel J , Strakova P , Sebesta O , Rettich F , Cabanova V , Miterpakova M , Betasova L , Pesko J , Barbusinova E , McKee C , Osikowicz L , Sikutova S , Hubalek Z , Kosoy M . Parasitol Res 2020 119 (8) 2713-2717 Here, we provide the first mass molecular screening of medically important mosquitoes for Bartonella species using multiple genetic markers. We examined a total of 72,115 mosquito specimens, morphologically attributed to Aedes vexans (61,050 individuals), Culex pipiens (10,484 individuals) and species of the Anopheles maculipennis complex (581 individuals) for Bartonella spp. The initial screening yielded 63 Bartonella-positive A. vexans mosquitoes (mean prevalence 0.1%), 34 Bartonella-positive C. pipiens mosquitoes (mean prevalence 0.3%) and 158 Bartonella-positive A. maculipennis group mosquitoes (mean prevalence 27.2%). Several different Bartonella ITS sequences were recovered. This study highlights the need for molecular screening of mosquitoes, the most important vectors of arthropod-borne pathogens, for potential bacterial agents. |
Longitudinal study of bacterial infectious agents in a community of small mammals in New Mexico
Goodrich I , McKee C , Kosoy M . Vector Borne Zoonotic Dis 2020 20 (7) 496-508 Background and Objectives: Vector-borne bacterial diseases represent a substantial public health burden and rodents have been recognized as important reservoir hosts for many zoonotic pathogens. This study investigates bacterial pathogens in a small mammal community of the southwestern United States of America. Methods: A total of 473 samples from 13 wild rodent and 1 lagomorph species were tested for pathogens of public health significance: Bartonella, Brucella, Yersinia, Borrelia, Rickettsia spp., and Anaplasma phagocytophilum. Results: Three animals were positive for Yersinia pestis, and one Sylvilagus audubonii had a novel Borrelia sp. of the relapsing fever group. No Brucella, Rickettsia, or A. phagocytophilum infections were detected. Bartonella prevalence ranged between 0% and 87.5% by animal species, with 74.3% in the predominant Neotoma micropus and 78% in the second most abundant N. albigula. The mean duration of Bartonella bacteremia in mark-recaptured N. micropus and N. albigula was 4.4 months, ranging from <1 to 18 months, and differed among Bartonella genogroups. Phylogenetic analysis of the Bartonella citrate synthase gene (gltA) revealed 9 genogroups and 13 subgroups. Seven genogroups clustered with known or previously reported Bartonella species and strains while two were distant enough to represent new Bartonella species. We report, for the first time, the detection of Bartonella alsatica in North America in Sylvilagus audubonii and expand the known host range of Bartonella washoensis to include Otospermophilus variegatus. Interpretation and Conclusion: This work broadens our knowledge of the hosts and geographic range of bacterial pathogens that could guide future surveillance efforts and improves our understanding of the dynamics of Bartonella infection in wild small mammals. |
Host phylogeny, geographic overlap, and roost sharing shape parasite communities in European bats
McKee CD , Krawczyk AI , Sandor AD , Gorfol T , Foldvari M , Foldvari G , Dekeukeleire D , Haarsma AJ , Kosoy MY , Webb CT , Sprong H . Front Ecol Evol 2019 7 How multitrophic relationships between wildlife communities and their ectoparasitic vectors interact to shape the diversity of vector-borne microorganisms is poorly understood. Nested levels of dependence among microbes, vectors, and vertebrate hosts may have complicated effects on both microbial community assembly and evolution. We examined Bartonella sequences from European bats and their ectoparasites with a combination of network analysis, Bayesian phylogenetics, tip-association and cophylogeny tests, and linear regression to understand the ecological and evolutionary processes that shape parasite communities. We detected seven bat-ectoparasite-Bartonella communities that can be differentiated based on bat families and roosting patterns. Tips of the Bartonella tree were significantly clustered by host taxonomy and geography. We also found significant evidence of evolutionary congruence between bat host and Bartonella phylogenies, indicating that bacterial species have evolved to infect related bat species. Exploring these ecological and evolutionary associations further, we found that sharing of Bartonella species among bat hosts was strongly associated with host phylogenetic distance and roost sharing and less strongly with geographic range overlap. Ectoparasite sharing between hosts was strongly predicted by host phylogenetic distance, roost sharing, and geographic overlap but had no additive effect on Bartonella sharing. Finally, historical Bartonella host-switching was more frequent for closely related bats after accounting for sampling bias among bat species. This study helps to disentangle the complex ecology and evolution of Bartonella bacteria in bat species and their arthropod vectors. Our work provides insight into the important mechanisms that partition parasite communities among hosts, particularly the effect of host phylogeny and roost sharing, and could help to elucidate the evolutionary patterns of other diverse vector-borne microorganisms. |
Co-occurrence of chronic traumatic encephalopathy and prion disease
Nemani SK , Notari S , Cali I , Alvarez VE , Kofskey D , Cohen M , Stern RA , Appleby B , Abrams J , Schonberger L , McKee A , Gambetti P . Acta Neuropathol Commun 2018 6 (1) 140 Chronic traumatic encephalopathy (CTE) is a neurodegenerative disease associated with repetitive traumatic brain injury (TBI). CTE is generally found in athletes participating in contact sports and military personnel exposed to explosive blasts but can also affect civilians. Clinically and pathologically, CTE overlaps with post-traumatic stress disorder (PTSD), a term mostly used in a clinical context. The histopathology of CTE is defined by the deposition of hyperphosphorylated tau protein in neurons and astrocytes preferentially with perivascular distribution and at the depths of the cortical sulci. In addition to hyperphosphorylated tau, other pathologic proteins are deposited in CTE, including amyloid beta (Abeta), transactive response (TAR) DNA-binding protein 43 kDa (TDP-43) and alpha-synuclein. However, the coexistence of prion disease in CTE has not been observed. We report three cases of histopathologically validated CTE with co-existing sporadic prion disease. Two were identified in a cohort of 55 pathologically verified cases of CTE submitted to the CTE Center of Boston University. One was identified among brain tissues submitted to the National Prion Disease Pathology Surveillance Center of Case Western Reserve University. The histopathological phenotype and properties of the abnormal, disease-related prion protein (PrP(D)) of the three CTE cases were examined using lesion profile, immunohistochemistry, electrophoresis and conformational tests. Subjects with sporadic Creutzfeldt-Jakob disease (sCJD) matched for age, PrP genotype and PrP(D) type were used as controls. The histopathology phenotype and PrP(D) properties of the three CTE subjects showed no significant differences from their respective sCJD controls suggesting that recurring neurotrauma or coexisting CTE pathology did not detectably impact the prion disease phenotype and PrP(D) conformational characteristics. Based on the reported incidence of sporadic prion disease, the detection of two cases with sCJD in the CTE Center series of 55 CTE cases by chance alone would be highly unlikely (p = 8.93*10(- 6)). Nevertheless, examination of a larger cohort of CTE is required to conclusively determine whether the risk of CJD is significantly increased in patients with CTE. |
Human exposure to novel Bartonella species from contact with fruit bats
Bai Y , Osinubi MOV , Osikowicz L , McKee C , Vora NM , Rizzo MR , Recuenco S , Davis L , Niezgoda M , Ehimiyein AM , Kia GSN , Oyemakinde A , Adeniyi OS , Gbadegesin YH , Saliman OA , Ogunniyi A , Ogunkoya AB , Kosoy MY . Emerg Infect Dis 2018 24 (12) 2317-2323 Twice a year in southwestern Nigeria, during a traditional bat festival, community participants enter designated caves to capture bats, which are then consumed for food or traded. We investigated the presence of Bartonella species in Egyptian fruit bats (Rousettus aegyptiacus) and bat flies (Eucampsipoda africana) from these caves and assessed whether Bartonella infections had occurred in persons from the surrounding communities. Our results indicate that these bats and flies harbor Bartonella strains, which multilocus sequence typing indicated probably represent a novel Bartonella species, proposed as Bartonella rousetti. In serum from 8 of 204 persons, we detected antibodies to B. rousetti without cross-reactivity to other Bartonella species. This work suggests that bat-associated Bartonella strains might be capable of infecting humans. |
Acquisition of Bartonella elizabethae by experimentally exposed oriental rat fleas (Xenopsylla cheopis; Siphonaptera, Pulicidae) and excretion of Bartonella DNA in flea feces
McKee CD , Osikowicz LM , Schwedhelm TR , Maes SE , Enscore RE , Gage KL , Kosoy MY . J Med Entomol 2018 55 (5) 1292-1298 Few studies have been able to provide experimental evidence of the ability of fleas to maintain rodent-associated Bartonella infections and excrete these bacteria. These data are important for understanding the transmission cycles and prevalence of these bacteria in hosts and vectors. We used an artificial feeding approach to expose groups of the oriental rat flea (Xenopsylla cheopis Rothschild; Siphonaptera, Pulicidae) to rat blood inoculated with varying concentrations of Bartonella elizabethae Daly (Bartonellaceae: Rhizobiales). Flea populations were maintained by membrane feeding on pathogen-free bloodmeals for up to 13 d post infection. Individual fleas and pools of flea feces were tested for the presence of Bartonella DNA using molecular methods (quantitative and conventional polymerase chain reaction [PCR]). The threshold number of Bartonellae required in the infectious bloodmeal for fleas to be detected as positive was 106 colony-forming units per milliliter (CFU/ml). Individual fleas were capable of harboring infections for at least 13 d post infection and continuously excreted Bartonella DNA in their feces over the same period. This experiment demonstrated that X. cheopis are capable of acquiring and excreting B. elizabethae over several days. These results will guide future work to model and understand the role of X. cheopis in the natural transmission cycle of rodent-borne Bartonella species. Future experiments using this artificial feeding approach will be useful for examining the horizontal transmission of B. elizabethae or other rodent-associated Bartonella species to naive hosts and for determining the viability of excreted bacteria. |
Survey of parasitic bacteria in bat bugs, Colorado
McKee CD , Osikowicz LM , Schwedhelm TR , Bai Y , Castle KT , Kosoy MY . J Med Entomol 2018 55 (1) 237-241 Bat bugs (Cimex adjunctus Barber) (Hemiptera: Cimicidae) collected from big brown bats (Eptesicus fuscus Palisot de Beauvoir) in Colorado, United States were assessed for the presence of Bartonella, Brucella, and Yersinia spp. using molecular techniques. No evidence of Brucella or Yersinia infection was found in the 55 specimens collected; however, 4/55 (7.3%) of the specimens were positive for Bartonella DNA. Multi-locus characterization of Bartonella DNA shows that sequences in bat bugs are phylogenetically related to other Bartonella isolates and sequences from European bats. |
Genotyping of Bartonella bacteria and their animal hosts: current status and perspectives.
Kosoy M , McKee C , Albayrak L , Fofanov Y . Parasitology 2018 145 (5) 543-562 Growing evidence demonstrates that bacterial species diversity is substantial, and many of these species are pathogenic in some contexts or hosts. At the same time, laboratories and museums have collected valuable animal tissue and ectoparasite samples that may contain substantial novel information on bacterial prevalence and diversity. However, the identification of bacterial species is challenging, partly due to the difficulty in culturing many microbes and the reliance on molecular data. Although the genomics revolution will surely add to our knowledge of bacterial systematics, these approaches are not accessible to all researchers and rely predominantly on cultured isolates. Thus, there is a need for comprehensive molecular analyses capable of accurately genotyping bacteria from animal tissues or ectoparasites using common methods that will facilitate large-scale comparisons of species diversity and prevalence. To illustrate the challenges of genotyping bacteria, we focus on the genus Bartonella, vector-borne bacteria common in mammals. We highlight the value and limitations of commonly used techniques for genotyping bartonellae and make recommendations for researchers interested in studying the diversity of these bacteria in various samples. Our recommendations could be applicable to many bacterial taxa (with some modifications) and could lead to a more complete understanding of bacterial species diversity. |
Diversity and phylogenetic relationships among Bartonella strains from Thai bats.
McKee CD , Kosoy MY , Bai Y , Osikowicz LM , Franka R , Gilbert AT , Boonmar S , Rupprecht CE , Peruski LF . PLoS One 2017 12 (7) e0181696 Bartonellae are phylogenetically diverse, intracellular bacteria commonly found in mammals. Previous studies have demonstrated that bats have a high prevalence and diversity of Bartonella infections globally. Isolates (n = 42) were obtained from five bat species in four provinces of Thailand and analyzed using sequences of the citrate synthase gene (gltA). Sequences clustered into seven distinct genogroups; four of these genogroups displayed similarity with Bartonella spp. sequences from other bats in Southeast Asia, Africa, and Eastern Europe. Thirty of the isolates representing these seven genogroups were further characterized by sequencing four additional loci (ftsZ, nuoG, rpoB, and ITS) to clarify their evolutionary relationships with other Bartonella species and to assess patterns of diversity among strains. Among the seven genogroups, there were differences in the number of sequence variants, ranging from 1-5, and the amount of nucleotide divergence, ranging from 0.035-3.9%. Overall, these seven genogroups meet the criteria for distinction as novel Bartonella species, with sequence divergence among genogroups ranging from 6.4-15.8%. Evidence of intra- and intercontinental phylogenetic relationships and instances of homologous recombination among Bartonella genogroups in related bat species were found in Thai bats. |
Prevalence, diversity, and host associations of Bartonella strains in bats from Georgia (Caucasus).
Urushadze L , Bai Y , Osikowicz L , McKee C , Sidamonidze K , Putkaradze D , Imnadze P , Kandaurov A , Kuzmin I , Kosoy M . PLoS Negl Trop Dis 2017 11 (4) e0005428 Bartonella infections were investigated in seven species of bats from four regions of the Republic of Georgia. Of the 236 bats that were captured, 212 (90%) specimens were tested for Bartonella infection. Colonies identified as Bartonella were isolated from 105 (49.5%) of 212 bats Phylogenetic analysis based on sequence variation of the gltA gene differentiated 22 unique Bartonella genogroups. Genetic distances between these diverse genogroups were at the level of those observed between different Bartonella species described previously. Twenty-one reference strains from 19 representative genogroups were characterized using four additional genetic markers. Host specificity to bat genera or families was reported for several Bartonella genogroups. Some Bartonella genotypes found in bats clustered with those identified in dogs from Thailand and humans from Poland. |
Molecular Survey of Bacterial Zoonotic Agents in Bats from the Country of Georgia (Caucasus).
Bai Y , Urushadze L , Osikowicz L , McKee C , Kuzmin I , Kandaurov A , Babuadze G , Natradze I , Imnadze P , Kosoy M . PLoS One 2017 12 (1) e0171175 Bats are important reservoirs for many zoonotic pathogens. However, no surveys of bacterial pathogens in bats have been performed in the Caucasus region. To understand the occurrence and distribution of bacterial infections in these mammals, 218 bats belonging to eight species collected from four regions of Georgia were examined for Bartonella, Brucella, Leptospira, and Yersinia using molecular approaches. Bartonella DNA was detected in 77 (35%) bats from all eight species and was distributed in all four regions. The prevalence ranged 6-50% per bat species. The Bartonella DNA represented 25 unique genetic variants that clustered into 21 lineages. Brucella DNA was detected in two Miniopterus schreibersii bats and in two Myotis blythii bats, all of which were from Imereti (west-central region). Leptospira DNA was detected in 25 (13%) bats that included four M. schreibersii bats and 21 M. blythii bats collected from two regions. The Leptospira sequences represented five genetic variants with one of them being closely related to the zoonotic pathogen L. interrogans (98.6% genetic identity). No Yersinia DNA was detected in the bats. Mixed infections were observed in several cases. One M. blythii bat and one M. schreibersii bat were co-infected with Bartonella, Brucella, and Leptospira; one M. blythii bat and one M. schreibersii bat were co-infected with Bartonella and Brucella; 15 M. blythii bats and three M. schreibersii bats were co-infected with Bartonella and Leptospira. Our results suggest that bats in Georgia are exposed to multiple bacterial infections. Further studies are needed to evaluate pathogenicity of these agents to bats and their zoonotic potential. |
Phylogenetic and geographic patterns of bartonella host shifts among bat species.
McKee CD , Hayman DT , Kosoy MY , Webb CT . Infect Genet Evol 2016 44 382-394 The influence of factors contributing to parasite diversity in individual hosts and communities are increasingly studied, but there has been less focus on the dominant processes leading to parasite diversification. Using bartonella infections in bats as a model system, we explored the influence of three processes that can contribute to bartonella diversification and lineage formation: (1) spatial correlation in the invasion and transmission of bartonella among bats (phylogeography); (2) divergent adaptation of bartonellae to bat hosts and arthropod vectors; and (3) evolutionary codivergence between bats and bartonellae. Using a combination of global fit techniques and ancestral state reconstruction, we found that codivergence appears to be the dominant process leading to diversification of bartonella in bats, with lineages of bartonellae corresponding to separate bat suborders, superfamilies, and families. Furthermore, we estimated the rates at which bartonellae shift bat hosts across taxonomic scales (suborders, superfamilies, and families) and found that transition rates decrease with increasing taxonomic distance, providing support for a mechanism that can contribute to the observed evolutionary congruence between bats and their associated bartonellae. While bartonella diversification is associated with host sympatry, the influence of this factor is minor compared to the influence of codivergence and there is a clear indication that some bartonella lineages span multiple regions, particularly between Africa and Southeast Asia. Divergent adaptation of bartonellae to bat hosts and arthropod vectors is apparent and can dilute the overall pattern of codivergence, however its importance in the formation of Bartonella lineages in bats is small relative to codivergence. We argue that exploring all three of these processes yields a more complete understanding of bat-bartonella relationships and the evolution of the genus Bartonella, generally. Application of these methods to other infectious bacteria and viruses could uncover common processes that lead to parasite diversification and the formation of host-parasite relationships. |
Classification of Bartonella strains associated with straw-colored fruit bats (Eidolon helvum) across Africa using a multi-locus sequence typing platform.
Bai Y , Hayman DT , McKee CD , Kosoy MY . PLoS Negl Trop Dis 2015 9 (1) e0003478 Bartonellae are facultative intracellular bacteria and are highly adapted to their mammalian host cell niches. Straw-colored fruit bats (Eidolon helvum) are commonly infected with several bartonella strains. To elucidate the genetic diversity of these bartonella strains, we analyzed 79 bartonella isolates from straw-colored fruit bats in seven countries across Africa (Cameroon, Annobon island of Equatorial Guinea, Ghana, Kenya, Nigeria, Tanzania, and Uganda) using a multi-locus sequencing typing (MLST) approach based on nucleotide sequences of eight loci (ftsZ, gltA, nuoG, ribC, rpoB, ssrA, ITS, and 16S rRNA). The analysis of each locus but ribC demonstrated clustering of the isolates into six genogroups (E1 - E5 and Ew), while ribC was absent in the isolates belonging to the genogroup Ew. In general, grouping of all isolates by each locus was mutually supportive; however, nuoG, gltA, and rpoB showed some incongruity with other loci in several strains, suggesting a possibility of recombination events, which were confirmed by network analyses and recombination/mutation rate ratio (r/m) estimations. The MLST scheme revealed 45 unique sequence types (ST1 - 45) among the analyzed bartonella isolates. Phylogenetic analysis of concatenated sequences supported the discrimination of six phylogenetic lineages (E1 - E5 and Ew) corresponding to separate and unique Bartonella species. One of the defined lineages, Ew, consisted of only two STs (ST1 and ST2), and comprised more than one-quarter of the analyzed isolates, while other lineages contained higher numbers of STs with a smaller number of isolates belonging to each lineage. The low number of allelic polymorphisms of isolates belonging to Ew suggests a more recent origin for this species. Our findings suggest that at least six Bartonella species are associated with straw-colored fruit bats, and that distinct STs can be found across the distribution of this bat species, including in populations of bats which are genetically distinct. |
Regulatory T cells modulate granulomatous inflammation in an HLA-DP2 transgenic murine model of beryllium-induced disease
Mack DG , Falta MT , McKee AS , Martin AK , Simonian PL , Crawford F , Gordon T , Mercer RR , Hoover MD , Marrack P , Kappler JW , Tuder RM , Fontenot AP . Proc Natl Acad Sci U S A 2014 111 (23) 8553-8 Susceptibility to chronic beryllium disease (CBD) is linked to certain HLA-DP molecules, including HLA-DP2. To elucidate the molecular basis of this association, we exposed mice transgenic (Tg) for HLA-DP2 to beryllium oxide (BeO) via oropharyngeal aspiration. As opposed to WT mice, BeO-exposed HLA-DP2 Tg mice developed mononuclear infiltrates in a peribronchovascular distribution that were composed of CD4(+) T cells and included regulatory T (Treg) cells. Beryllium-responsive, HLA-DP2-restricted CD4(+) T cells expressing IFN-gamma and IL-2 were present in BeO-exposed HLA-DP2 Tg mice and not in WT mice. Using Be-loaded HLA-DP2-peptide tetramers, we identified Be-specific CD4(+) T cells in the mouse lung that recognize identical ligands as CD4(+) T cells derived from the human lung. Importantly, a subset of HLA-DP2 tetramer-binding CD4(+) T cells expressed forkhead box P3, consistent with the expansion of antigen-specific Treg cells. Depletion of Treg cells in BeO-exposed HLA-DP2 Tg mice exacerbated lung inflammation and enhanced granuloma formation. These findings document, for the first time to our knowledge, the development of a Be-specific adaptive immune response in mice expressing HLA-DP2 and the ability of Treg cells to modulate the beryllium-induced granulomatous immune response. |
Physician nonadherence with a hepatitis C screening program
Southern WN , Drainoni ML , Smith BD , Koppelman E , McKee MD , Christiansen CL , Gifford AL , Weinbaum CM , Litwin AH . Qual Manag Health Care 2014 23 (1) 1-9 BACKGROUND: Testing for patients at risk for hepatitis C virus (HCV) infection is recommended, but it is unclear whether providers adhere to testing guidelines. We aimed to measure adherence to an HCV screening protocol during a multifaceted continuous intervention. SUBJECTS AND METHODS: Prospective cohort design to examine the associations between patient-level, physician-level, and visit-level characteristics and adherence to an HCV screening protocol. Study participants included all patients with a visit to 1 of the 3 study clinics and the physicians who cared for them. Adherence to the HCV screening protocol and patient-level, physician-level, and visit-level predictors of adherence were measured. RESULTS: A total of 8981 patients and 154 physicians were examined. Overall protocol adherence rate was 36.1%. In multivariate analysis, patient male sex (odds ratio [OR] = 1.18), new patient (OR = 1.23), morning visit (OR = 1.32), and patients' preferred language being non-English (OR = 0.87) were significantly associated with screening adherence. There was a wide variation in overall adherence among physicians (range, 0%-92.4%). Screening adherence continuously declined from 59.1% in week 1 of the study to 13.7% in week 15 (final week). When implementing complex clinical practice guidelines, planners should address physician attitudinal barriers as well as gaps in knowledge to maximize adherence. |
Effectiveness of a risk screener in identifying hepatitis C virus in a primary care setting
Drainoni ML , Litwin AN , Smith BD , Koppelman EA , McKee MD , Christiansen CL , Gifford AL , Weinbaum CM , Southern WN . Am J Public Health 2012 102 (11) e115-21 OBJECTIVES: We evaluated an intervention designed to identify patients at risk for hepatitis C virus (HCV) through a risk screener used by primary care providers. METHODS: A clinical reminder sticker prompted physicians at 3 urban clinics to screen patients for 12 risk factors and order HCV testing if any risks were present. Risk factor data were collected from the sticker; demographic and testing data were extracted from electronic medical records. We used the t test, chi(2) test, and rank-sum test to compare patients who had and had not been screened and developed an analytic model to identify the incremental value of each element of the screener. RESULTS: Among screened patients, 27.8% (n = 902) were identified as having at least 1 risk factor. Of screened patients with risk factors, 55.4% (n = 500) were tested for HCV. Our analysis showed that 7 elements (injection drug use, intranasal drug use, elevated alanine aminotransferase, transfusions before 1992, ≥ 20 lifetime sex partners, maternal HCV, existing liver disease) accounted for all HCV infections identified. CONCLUSIONS: A brief risk screener with a paper-based clinical reminder was effective in increasing HCV testing in a primary care setting. (Am J Public Health. Published online ahead of print September 20, 2012: e1-e7. doi:10.2105/AJPH.2012.300659). |
Primary care-based interventions are associated with increases in hepatitis C virus testing for patients at risk
Litwin AH , Smith BD , Drainoni ML , McKee D , Gifford AL , Koppelman E , Christiansen CL , Weinbaum CM , Southern WN . Dig Liver Dis 2012 44 (6) 497-503 BACKGROUND: An estimated 3.2 million persons are chronically infected with the hepatitis C virus (HCV) in the U.S. Effective treatment is available, but approximately 50% of patients are not aware that they are infected. Optimal testing strategies have not been described. METHODS: The Hepatitis C Assessment and Testing Project (HepCAT) was a serial cross-sectional evaluation of two community-based interventions designed to increase HCV testing in urban primary care clinics in comparison with a baseline period. The first intervention (risk-based screener) prompted physicians to order HCV tests based on the presence of HCV-related risks. The second intervention (birth cohort) prompted physicians to order HCV tests on all patients born within a high-prevalence birth cohort (1945-1964). The study was conducted at three primary care clinics in the Bronx, New York. RESULTS: Both interventions were associated with an increased proportion of patients tested for HCV from 6.0% at baseline to 13.1% during the risk-based screener period (P<0.001) and 9.9% during the birth cohort period (P<0.001). CONCLUSIONS: Two simple clinical reminder interventions were associated with significantly increased HCV testing rates. Our findings suggest that HCV screening programs, using either a risk-based or birth cohort strategy, should be adopted in primary care settings so that HCV-infected patients may benefit from antiviral treatment. |
Hepatitis C testing practices and prevalence in a high-risk urban ambulatory care setting
Southern WN , Drainoni ML , Smith BD , Christiansen CL , McKee D , Gifford AL , Weinbaum CM , Thompson D , Koppelman E , Maher S , Litwin AH . J Viral Hepat 2011 18 (7) 474-481 SUMMARY: Approximately 3.2 million persons are chronically infected with the hepatitis C virus (HCV) in the U.S.; most are not aware of their infection. Our objectives were to examine HCV testing practices to determine which patient characteristics are associated with HCV testing and positivity, and to estimate the prevalence of HCV infection in a high-risk urban population. The study subjects were all patients included in the baseline phase of the Hepatitis C Assessment and Testing Project (HepCAT), a serial cross-sectional study of HCV screening strategies. We examined all patients with a clinic visit to Montefiore Medical Center from 1/1/08 to 2/29/08. Demographic information, laboratory data and ICD-9 diagnostic codes from 3/1/97-2/29/08 were extracted from the electronic medical record. Risk factors for HCV were defined based on birth date, ICD-9 codes and laboratory data. The prevalence of HCV infection was estimated assuming that untested subjects would test positive at the same rate as tested subjects, based on risk-factors. Of 9579 subjects examined, 3803 (39.7%) had been tested for HCV and 438 (11.5%) were positive. The overall prevalence of HCV infection was estimated to be 7.7%. Risk factors associated with being tested and anti-HCV positivity included: born in the high-prevalence birth-cohort (1945-64), substance abuse, HIV infection, alcohol abuse, diagnosis of cirrhosis, end-stage renal disease, and alanine transaminase elevation. In a high-risk urban population, a significant proportion of patients were tested for HCV and the prevalence of HCV infection was high. Physicians appear to use a risk-based screening strategy to identify HCV infection. |
The case for developing consensus standards for research in microbial pathogenesis: bacillus anthracis toxins as an example
Hughes MA , Burns DL , Juris SJ , Tang WJ , Clement KH , Eaton LJ , Kelly-Cirino CD , McKee ML , Powell BS , Bishop BL , Rudge TL , Shine N , Verma A , Willis MS , Morse SA . Infect Immun 2009 77 (10) 4182-6 Communication between research laboratories within a given field is often an important key to rapid successes within that field. ... |
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