Prevalence and genetic diversity of Rhodococcus equi in wild boars (Sus scrofa), roe deer (Capreolus capreolus) and red deer (Cervus elaphus) in Poland.

Lucjan Witkowski,Michał Czopowicz,Jerzy Kita,Magdalena Rzewuska,Magdalena Kizerwetter-Świda,Dorota Chrobak-Chmiel,Mirosław Welz,Agata Anna Cisek

doi:10.1186/s12866-015-0445-1

Lucjan Witkowski, Michał Czopowicz + Show 6 more

Open Access

https://doi.org/10.1186/s12866-015-0445-1

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Abstract

BackgroundRhodococcus equi is now considered an emerging zoonotic pathogen. Sources and routes of human infection remain unclear but foodborne transmission seems to be the most probable way. Strains of pig or bovine type are most often isolated from human cases and moreover R. equi is present in submaxillary lymph nodes of apparently healthy pigs and wild boars intended for human consumption. The aim of this study was to estimate the prevalence of R. equi in submaxillary lymph nodes in wild boars, roe deer and red deer.ResultsSamples were collected from 936 animals and 27 R. equi strains were isolated, from 5.1 % of wild boars (23/452), 0.7 % of red deer (2/272) and 0.9 % of roe deer (2/212). Genetic diversity of all 27 isolates was studied using VspI-PFGE method, resulting in the detection of 25 PFGE patterns and four PFGE clusters. PFGE patterns of the isolates were compared with virulence plasmid types and no concordance was observed.ConclusionsR. equi was present in wild animal tissues and consumption of the game may be a potential source of R. equi infection for humans. To the authors’ best knowledge, this is the first epidemiological report of R. equi prevalence in tissues of roe deer and red deer. However, risk associated with wild ruminant consumption seems marginal.Investigation of R. equi transmission between animals and humans based exclusively on types of virulence plasmids seems to be insufficient to identify sources of R. equi infection for people.

Highlights

Rhodococcus equi is considered an emerging zoonotic pathogen
Afterwards, R. equi was isolated from 6.6 % mesenteric and submaxillary lymph nodes with lymphadenitis in wild boars in Brazil, but the bacteria were not detected in lymph nodes without lymphadenitis [12, 13]
The aim of this study was to estimate the prevalence of R. equi in wild boars, roe deer and red deer carcasses intended for human consumption in Poland and to determine the genetic diversity of the isolates

Summary

Introduction

Rhodococcus equi is considered an emerging zoonotic pathogen. Sources and routes of human infection remain unclear but foodborne transmission seems to be the most probable way. Strains of pig or bovine type are most often isolated from human cases and R. equi is present in submaxillary lymph nodes of apparently healthy pigs and wild boars intended for human consumption. Only foals up to six months of age have a unique susceptibility to clinical disease and it is a major concern to the equine breeding industry [6]. Clinical form of this disease known as rhodococcosis mostly manifesting itself with abscesses or lymphadenitis has been reported occasionally in other farm animals. Very high R. equi prevalence of 52 % was noticed in submaxillary lymph nodes of wild boars in Japan [20].

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