An Investigation ofBartonellaspp.,Rickettsia typhi, and Seoul Hantavirus in Rats (Rattusspp.) from an Inner-City Neighborhood of Vancouver, Canada: Is Pathogen Presence a Reflection of Global and Local Rat Population Structure?

Abstract

Urban Norway and black rats (Rattus norvegicus and Rattus rattus) are reservoirs for variety of zoonotic pathogens. Many of these pathogens, including Rickettsia typhi, Bartonella spp., and Seoul hantavirus (SEOV), are thought to be endemic in rat populations worldwide; however, past field research has found these organisms to be absent in certain rat populations. Rats (Rattus spp.) from an inner city neighborhood of Vancouver, Canada, were tested for exposure to and/or infection with SEOV and R. typhi (using serology and PCR), as well as Bartonella spp. (using culture and sequencing). Approximately 25% of 404 rats tested were infected with Bartonella tribocorum, which demonstrated significant geographic clustering within the study area. Infection was associated with both season and sexual maturity. Seroreactivity against R. typhi and SEOV was observed in 0.36% and 1.45% of 553 rats tested, respectively, although PCR screening results for these pathogens were negative, suggesting that they are not endemic in the study population. Overall, these results suggest that the geographic distribution of rat-associated zoonoses, including R. typhi, SEOV, and Bartonella spp., is less ubiquitous than previously appreciated, and is likely dependent on patterns of dispersion and establishment of the rat reservoir host. Further study on global and local Rattus spp. population structures may help to elucidate the ecology of zoonotic organisms in these species.

Effects of Culling onLeptospira interrogansCarriage by Rats

“…Other vectorborne (e.g., fleaborne Rickettsia spp. [ 14 ]) or environmentally acquired (e.g., methicillin-resistant Staphylococcus aureus [ 15 ]) rat-associated pathogens might not be as easily influenced by culling. Future studies should determine the duration of effects induced by lethal control because effects on L. interrogans prevalence may wane with time.…”

The devil is in the details—Host disease and co‐infections are associated with zoonotic pathogen carriage in Norway rats (Rattus norvegicus)

“…We collected tissues and recorded the presence of macroscopic le- and in consultation with at least one other ACVP certified pathologist per lesion, we created a binary classification system to systematically and conservatively assess the presence/absence of the most frequent lesions (Rothenburger et al, 2019). To identify B. tribocorum, blood clots from 393 rats were cultured and then the species identity was confirmed with PCR by amplifying and sequencing the citrate synthase gene (gltA; Himsworth et al, 2015). Kidney tissues from 581 rats were tested by RT-PCR for the lipL32 gene for pathogenic Leptospira sp.…”

Beyond abundance: How microenvironmental features and weather influence Bartonella tribocorum infection in wild Norway rats (Rattus norvegicus)

“…Blood clot samples from 393 rats were cultured for Bartonella spp. and the species identity was confirmed as B. tribocorum by PCR (Himsworth et al., ). The University of British Columbia's Animal Care Committee (A11‐0087) approved this study.…”

“…This association has prompted researchers to investigate individual‐level factors associated with Bartonella spp. carriage in rodents that include age, body mass, sex, sexual maturity and flea abundance (Gutiérrez et al., ; Himsworth et al., ; Jardine, Waldner, Wobeser, & Leighton, ).…”

“…The prevalence of Bartonella spp. varies among geographical locations, even at small scales (Himsworth et al., ; Rothenburger, Himsworth, Nemeth, Pearl, & Jardine, ). The reason(s) for this variability is not understood, although it may be related to weather and features of the microenvironment (Ayral et al., ; Rothenburger et al., ).…”