NRU :: Browsing by Author "Gillespie, Thomas R."

Browsing by Author "Gillespie, Thomas R."

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Antibiotic-Resistant Escherichia coli and Class 1 Integrons in Humans, Domestic Animals, and Wild Primates in Rural Uganda
(Applied and environmental microbiology, 2018) Weiss, Debora; Wallace, Ryan M.; Rwego, Innocent B.; Gillespie, Thomas R.; Chapman, Colin A.; Singer, Randall S.; Goldberg, Tony L.
Antibiotic resistance is a global concern, although it has been studied most extensively in developed countries. We studied Escherichia coli and class 1 integrons in western Uganda by analyzing 1,685 isolates from people, domestic animals, and wild nonhuman primates near two national parks. Overall, 499 isolates (29.6%) were resistant to at least one of 11 antibiotics tested. The frequency of resistance reached 20.3% of isolates for trimethoprim-sulfamethoxazole but was nearly zero for the less commonly available antibiotics ciprofloxacin (0.4%), gentamicin (0.2%), and ceftiofur (0.1%). The frequency of resistance was 57.4% in isolates from people, 19.5% in isolates from domestic animals, and 16.3% in isolates from wild nonhuman primates. Isolates of livestock and primate origin displayed multidrug resistance patterns identical to those of human-origin isolates. The percentage of resistant isolates in people was higher near Kibale National Park (64.3%) than near Bwindi Impenetrable National Park (34.6%), perhaps reflecting local socioeconomic or ecological conditions. Across antibiotics, resistance correlated negatively with the local price of the antibiotic, with the most expensive antibiotics (nalidixic acid and ciprofloxacin) showing near-zero resistance. Among phenotypically resistant isolates, 33.2% harbored class 1 integrons containing 11 common resistance genes arranged into nine distinct gene cassettes, five of which were present in isolates from multiple host species. Overall, these results show that phenotypic resistance and class 1 integrons are distributed broadly among E. coli isolates from different host species in this region, where local socioeconomic and ecological conditions may facilitate widespread diffusion of bacteria or resistance-conferring genetic elements.
Best Practice Guidelines for Health Monitoring and Disease Control in Great Ape Populations
(Occasional Papers of the IUCN Species Survival Commission, 2015) Gilardi, Kirsten V.; Gillespie, Thomas R.; Kalema-Zikusoka, Gladys; Köndgen, Sophie; Mugisha, Lawrence; Rwego, Innocent
For everyone: compulsory 5-day* quarantine before going to the chimpanzee research camps. The quarantine period starts on Friday afternoon, when assistants come back to the park after their week off, and ends ve days later on Wednesday afternoon. In normal routines, no one should join the quarantine later than Friday, as it will interrupt the quarantine cycle, in which case quarantine needs to start all over again. Travellers arriving on days other than Friday (international travellers or coming from Abidjan) can start their quarantine in north camp so as not to interrupt the routine quarantine.
Effects of anthropogenic and demographic factors on patterns of parasitism in African small mammal communities
(Parasitology, 2015) Salzer, Johanna S.; Carroll, Darin S.; Newkirk, Amanda Jo Williams; Lang, Stefanie; Peterhans, Julian Kerbis; Rwego, Innocent B.; Ockers, Sandra; Gillespie, Thomas R.
Habitatdisturbance oftenresults in alterations in community structure of smallmammals.Additionally, the parasitesharboured by these small mammals may be impacted by environmental changes or indirectly affected by changes in available hosts. To improve our understanding of this interplay, we examined the patterns of parasitism in small mammal communities from a variety of habitats in forested Uganda. Small mammals were collected from areas experiencing variable habitat disturbance, host densityandspecies richness.The analysis focusedon3most abundant rodent species,Lophuromys aquilus,Praomys jacksoni and Hylomyscus stella, and a diverse group of parasites they harbour. The impact of various habitat and host community factors on parasite prevalence was examined using linear regression and Spearman’s rank-order correlation. We further investigated the parasite communities associated with each individual using correspondence analysis. We determined that, parasite prevalence and richness may be occasionally influenced by community and habitat factors, but taxonomy is a driving force in influencing the parasite community harboured by an individual host. Ultimately, applying general principles across a broad range of disturbance levels and diverse host communities needs to be approached with caution in complex communities.
Forest Fragmentation as Cause of Bacterial Transmission among Nonhuman Primates, Humans, and Livestock, Uganda
(Emerging infectious diseases, 2008) Goldberg, Tony L.; Gillespie, Thomas R.; Rwego, Innocent B.; Estoff, Elizabeth L.; Chapman, Colin A.
We conducted a prospective study of bacterial transmission among humans, nonhuman primates (primates hereafter), and livestock in western Uganda. Humans living near forest fragments harbored Escherichia coli bacteria that were ≈75% more similar to bacteria from primates in those fragments than to bacteria from primates in nearby undisturbed forests. Genetic similarity between human/livestock and primate bacteria increased ≈3-fold as anthropogenic disturbance within forest fragments increased from moderate to high. Bacteria harbored by humans and livestock were approximately twice as similar to those of red-tailed guenons, which habitually enter human settlements to raid crops, than to bacteria of other primate species. Tending livestock, experiencing gastrointestinal symptoms, and residing near a disturbed forest fragment increased genetic similarity between a participant’s bacteria and those of nearby primates. Forest fragmentation, anthropogenic disturbance within fragments, primate ecology, and human behavior all influence bidirectional, interspecific bacterial transmission. Targeted interventions on any of these levels should reduce disease transmission and emergence.
Giardia sp. and Cryptosporidium sp. Infections in Primates in Fragmented and Undisturbed Forest in Western Uganda
(Journal of Parasitology, 2007) Salzer, Johanna S.; Rwego, Innocent B.; Goldberg, Tony L.; Kuhlenschmidt, Mark S.; Gillespie, Thomas R.
The molecular identification of species and genotypes of Giardia spp. infecting wild mammals represents the most reliable tool to understand the role played by these animals as reservoirs of cysts infectious for human and other animals. Of 139 fecal samples collected from fallow deer (Dama dama L.) hunted in a Natural Reserve of northern Italy, the prevalence of Giardia sp. was 11.5% (16 of 139 animals), and it was higher in fawns than in older animals. Fragments of the beta-giardin and triose phosphate isomerase (tpi) genes were successfully polymerase chain reaction amplified and sequenced from 8 isolates. No sequence variation was observed between isolates at the 2 genetic loci. Sequence and phylogenetic analyses identified a Giardia duodenalis subtype that clusters with assemblage A isolates and that shows homologies of 98 and 97% at the beta-giardin and tpi loci, respectively, compared with the A1 subtype. Because the G. duodenalis subtype found in fecal samples of fallow deer has never been detected previously, its role as a pathogen for humans and domestic animals is unknown, but, considering its genetic distinctiveness, it is likely to be low.
Health And Disease In The People, Primates, And Domestic Animals Of Kibale National Park: Implications For Conservation
(Cambridge University Press, 2008) Goldberg, Tony L .; Gillespie, Thomas R.; Rwego, Innocent B.
In the not-too-distant past, infectious disease was viewed as akin to fire, earthquake, and tornado in its propensity to impact wild primates. Outbreaks were considered inherently unpredictable, “sweeping through” primate populations, wreaking havoc, and then subsiding. Primates were generally thought to rebound, such that the overall effect was a “blip on the radar,” a transient reduction in population numbers. The last approximately 10 years have demonstrated the “disease as natural disaster” paradigm to be woefully inaccurate. Infectious disease has emerged as a major threat to primate conservation. The case of Ebola virus and its devastating effects on chimpanzees (Pan troglodytes) and gorillas (Gorilla gorilla) in Gabon and Congo is perhaps the most dramatic example, with some estimates of local population declines above 80% (Leroy et al., 2004; Bermejo et al., 2006). Other pathogens such as Bacillus anthracis (the causative agent of anthrax), polio virus, and yellow fever virus have also caused epidemic mortality in apes and monkeys, to the extent that they are now seen as important drivers of primate population declines (Chapman et al., 2005; Leendertz et al., 2006; Nunn and Altizer, 2006). Despite these dramatic examples, the majority of primate pathogens probably exert chronic, sublethal effects on primates in the wild (most parasitic protozoa, helminths, and arthropods probably fall into this category). Although researchers are paying increasing attention to such agents, most studies to date have been either “prevalence surveys” or comparisons of prevalence across locations or habitat types.
High Rates of Escherichia coli Transmission between Livestock and Humans in Rural Uganda
(Journal of Clinical Microbiology, 2008) Rwego, Innocent B.; Gillespie, Thomas R.; Basuta, Gilbert Isabirye; Goldberg, Tony L.
Escherichia coli is a zoonotic bacterium that is important to both public health and livestock economics. To date, most studies of zoonotic E. coli transmission have been conducted in developed nations with industrialized agricultural economies. In this study, E. coli bacteria were collected from people and livestock in two communities in rural western Uganda in order to investigate patterns of interspecific bacterial transmission in a developing rural economy characterized by very close human-livestock associations. Six hundred seventy-two E. coli isolates were genotyped using repetitive element-PCR (Rep-PCR) fingerprinting, and genetic distances between populations of bacteria from different hosts and locations were calculated. Genetic distances between human and livestock bacteria were generally very low, indicating high rates of bacterial gene flow among host species. Bacteria from humans and livestock in the same communities were virtually indistinguishable genetically. Data from surveys administered at the time of sample collection showed that people who did not regularly wash their hands before eating harbored bacteria approximately twice as similar genetically to bacteria of their livestock as did people who regularly washed their hands before eating. These results suggest that both rates of human-livestock interactions and patterns of human hygiene affect human-livestock bacterial transmission in this setting. This conclusion has implications not only for human and livestock health in subsistence-based agricultural economies but also for the emergence of zoonotic diseases out of such areas as a result of increasing globalization.
Impact of Anthropogenic Disturbance on Native and Invasive Trypanosomes of Rodents in Forested Uganda
(EcoHealth, 2016) Salzer, Johanna S.; Pinto, C. Miguel; Grippi, Dylan C.; Newkirk, Amanda Jo Williams; Peterhans, Julian Kerbis; Rwego, Innocent B.; Carroll, Darin S.; Gillespie, Thomas R.
Habitat disturbance and anthropogenic change are globally associated with extinctions and invasive species introductions. Less understood is the impact of environmental change on the parasites harbored by endangered, extinct, and introduced species. To improve our understanding of the impacts of anthropogenic disturbance on such host–parasite interactions, we investigated an invasive trypanosome (Trypanosoma lewisi). We screened 348 individual small mammals, representing 26 species, from both forested and non-forested habitats in rural Uganda. Using microscopy and PCR, we identified 18% of individuals (order Rodentia) as positive for trypanosomes. Further phylogenetic analyses revealed two trypanosomes circulating—T. lewisi and T. varani. T. lewisi was found in seven species both native and invasive, while T. varani was identified in only three native forest species. The lack of T. varani in non-forested habitats suggests that it is a natural parasite of forest-dwelling rodents. Our findings suggest that anthropogenic disturbance may lead to spillover of an invasive parasite (T. lewisi) from non-native to native species, and lead to local co-extinction of a native parasite (T. varani) and native forest-dwelling hosts.
Killing of a Pearl-Spotted Owlet (Glaucidium perlatum) by Male Red Colobus Monkeys (Procolobus tephrosceles) in a Forest Fragment Near Kibale National Park, Uganda
(Official Journal of the American Society of Primatologists, 2006) Goldberg, Tony L.; Gillespie, Thomas R.; Rwego, Innocent B.; Kaganzi, Clovis
Adult male red colobus (Procolobus tephrosceles) were observed capturing and killing an owl (Glaucidium perlatum) in the Rurama forest fragment near Kibale National Park in western Uganda. The owl was not subsequently eaten by the colobus, their conspecifics, or the other primates present during the attack. Because the incident was preceded by an agonistic encounter with a raptor, the event is best interpreted as a misdirected antipredator behavior. Although antipredator behaviors are not unknown in red colobus, this is the first such incident directed against a raptor to be documented. Am. J. Primatol. 68:1–5, 2006. © 2006 Wiley-Liss, Inc.
Molecular Epidemiology of Cross-Species Giardia duodenalis Transmission in Western Uganda
(PLoS neglected tropical diseases, 2010) Johnston, Amanda R.; Gillespie, Thomas R.; Rwego, Innocent B.; McLachlan, Traci L. Tranby; Kent, Angela D.; Goldberg, Tony L.
Giardia duodenalis is prevalent in tropical settings where diverse opportunities exist for transmission between people and animals. We conducted a cross-sectional study of G. duodenalis in people, livestock, and wild primates near Kibale National Park, Uganda, where human-livestock-wildlife interaction is high due to habitat disturbance. Our goal was to infer the cross-species transmission potential of G. duodenalis using molecular methods and to investigate clinical consequences of infection.Real-time PCR on DNA extracted from fecal samples revealed a combined prevalence of G. duodenalis in people from three villages of 44/108 (40.7%), with prevalence reaching 67.5% in one village. Prevalence rates in livestock and primates were 12.4% and 11.1%, respectively. Age was associated with G. duodenalis infection in people (higher prevalence in individuals ≤15 years) and livestock (higher prevalence in subadult versus adult animals), but other potential risk factors in people (gender, contact with domestic animals, working in fields, working in forests, source of drinking water, and medication use) were not. G. duodenalis infection was not associated with gastrointestinal symptoms in people, nor was clinical disease noted in livestock or primates. Sequence analysis of four G. duodenalis genes identified assemblage AII in humans, assemblage BIV in humans and endangered red colobus monkeys, and assemblage E in livestock and red colobus, representing the first documentation of assemblage E in a non-human primate. In addition, genetic relationships within the BIV assemblage revealed sub-clades of identical G. duodenalis sequences from humans and red colobus.Our finding of G. duodenalis in people and primates (assemblage BIV) and livestock and primates (assemblage E) underscores that cross-species transmission of multiple G. duodenalis assemblages may occur in locations such as western Uganda where people, livestock, and primates overlap in their use of habitat. Our data also demonstrate a high but locally variable prevalence of G. duodenalis in people from western Uganda, but little evidence of associated clinical disease. Reverse zoonotic G. duodenalis transmission may be particularly frequent in tropical settings where anthropogenic habitat disturbance forces people and livestock to interact at high rates with wildlife, and this could have negative consequences for wildlife conservation. .
Patterns Of Gastrointestinal Bacterial Exchange Between Chimpanzees And Humans Involved In Research And Tourism In Western Uganda
(Biological Conservation, 2007) Goldberg, Tony L.; Gillespie, Thomas R.; Rwego, Innocent B.; Wheeler, Emily; Estoff, Elizabeth L.; Chapman, Colin A.
Ecological overlap may increase the risks of microbial exchange between humans and wild non-human primates. Escherichia coli bacteria were collected from chimpanzees and humans in Kibale National Park, western Uganda, in May and June 2004, in order to examine whether interaction between humans and apes in the wild might affect gastrointestinal bacterial communities in the two species. Chimpanzees harbored bacteria genetically more similar to those of humans employed in chimpanzee-directed research and tourism than to those of humans from a local village. Most humans (81.6%) and 4.4% of chimpanzees harbored at least one isolate resistant to locally available antibiotics. In isolates from both humans and chimpanzees, resistance was higher to five of these antibiotics than to Ceftiofur, an antibiotic not available in the region. These data indicate that humans and apes interacting in the wild can share genetically and phenotypically similar gastrointestinal bacteria, presumably originating from common environmental sources. Strategies to limit transmission of pathogens between humans and primates, whether that transmission is direct or indirect, would benefit both human health and primate conservation.
Serologic Evidence For Circulating Orthopoxviruses In Peridomestic Rodents From Rural Uganda
(Journal of wildlife diseases, 2013) Salzer, Johanna S.; Carroll, Darin S.; Rwego, Innocent B.; Li, Yu; Falendysz, Elizabeth A.; Shisler, Joanna L.; Karem, Kevin L.; Damon, Inger K.; Gillespie, Thomas R.
The prevalence of orthopoxviruses (OPXV) among wildlife, including monkeypox virus (MPXV), remains largely unknown. Outbreaks of human monkeypox in central Africa have been associated with hunting, butchering, and consuming infected forest animals, primarily rodents and primates. Monkeypox cases have not been reported in east Africa, where human contact with wildlife is more limited. Whether this lack of human disease is due to the absence of MPXV in rodents is unknown. However, testing of wildlife beyond the known geographic distribution of human cases of monkeypox has rarely been conducted, limiting our knowledge of the natural distribution of MPXV and other OPXV. To improve our understanding of the natural distribution of OPXV in Africa and related risks to public health, we conducted a serosurvey of peridomestic rodents (Rattus rattus) in and around traditional dwellings in Kabarole District, Uganda, from May 2008 to July 2008. We tested for OPXV antibody in areas free of human monkeypox. Sera from 41%of the R. rattus individuals sampled reacted to OPXV-specific proteins from multiple, purified OPXV samples, but did not react by enzyme-linked immunosorbent assay. The specific OPXV could not be identified because poxvirus DNA was undetectable in corresponding tissues. We conclude that an OPXV or a similar poxvirus is circulating among wild rodents in Uganda. With the known geographic range of OPXV in rodents now increased, factors that dictate OPXV prevalence and disease will be identified.
Wild Chimpanzees Infected with 5 Plasmodium Species
(Emerging infectious diseases, 2010) Kaiser, Marco; Löwa, Anna; Ulrich, Markus; Ellerbrok, Heinz; Goffe, Adeelia S.; Blasse, Anja; Zommers, Zinta; Couacy-Hymann, Emmanuel; Babweteera, Fred; Zuberbühler, Klaus; Metzger, Sonja; Geidel, Sebastian; Boesch, Christophe; Gillespie, Thomas R.; Leendertz, Fabian H.
Despite ongoing and, in some regions, escalating morbidity and mortality rates associated with malariacausing parasites, the evolutionary epidemiology of Plasmodium spp. is not well characterized. Classical studies of the blood pathogens of primates have found protozoa resembling human malaria parasites in chimpanzees and gorillas (1); however, these studies were limited to microscopy, negating conclusions regarding evolutionary relationships between human and ape parasites. Recent studies that used molecular approaches showed that captive and wild chimpanzees (Pan troglodytes) and lowland gorillas (Gorilla gorilla), as well as captive bonobos (Pan paniscus), harbor parasites broadly related to P. falciparum (2–5); wild and captive gorillas and captive bonobos and chimpanzees are sometimes infected with P. falciparum itself (4–6). Further, captive chimpanzees and bonobos have been shown to have malaria parasites related to human P. ovale and P. malariae (6–8); P. vivax has been identified in various monkeys and 1 semiwild chimpanzee (5,9). Recently, P. knowlesi, a simian malaria species, became the fifth human-infecting species (10), highlighting the possibility of transmission of new Plasmodium spp. from wild primates to humans.

Browsing by Author "Gillespie, Thomas R."

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