First investigation of pathogenic bacteria, protozoa and viruses in rodents and shrews in context of forest-savannah-urban areas interface in the city of Franceville (Gabon).

Joa Braïthe Mangombi,Mathieu Bourgarel,Jean-Bernard Lekana-Douki,Octavie Banga,Florence Fenollar,Nadine N’Dilimabaka,Eric Leroy,Oleg Mediannikov,Sydney Maghendji-Nzondo,Wanda Markotter

doi:10.1371/journal.pone.0248244

Abstract

Rodents are reservoirs of numerous zoonotic diseases caused by bacteria, protozoans, or viruses. In Gabon, the circulation and maintenance of rodent-borne zoonotic infectious agents are poorly studied and are often limited to one type of pathogen. Among the three existing studies on this topic, two are focused on a zoonotic virus, and the third is focused on rodent Plasmodium. In this study, we searched for a wide range of bacteria, protozoa and viruses in different organs of rodents from the town of Franceville in Gabon. Samples from one hundred and ninety-eight (198) small mammals captured, including two invasive rodent species, five native rodent species and 19 shrews belonging to the Soricidae family, were screened. The investigated pathogens were bacteria from the Rickettsiaceae and Anaplasmataceae families, Mycoplasma spp., Bartonella spp., Borrelia spp., Orientia spp., Occidentia spp., Leptospira spp., Streptobacillus moniliformis, Coxiella burnetii, and Yersinia pestis; parasites from class Kinetoplastida spp. (Leishmania spp., Trypanosoma spp.), Piroplasmidae spp., and Toxoplasma gondii; and viruses from Paramyxoviridae, Hantaviridae, Flaviviridae and Mammarenavirus spp. We identified the following pathogenic bacteria: Anaplasma spp. (8.1%; 16/198), Bartonella spp. (6.6%; 13/198), Coxiella spp. (5.1%; 10/198) and Leptospira spp. (3.5%; 7/198); and protozoans: Piroplasma sp. (1%; 2/198), Toxoplasma gondii (0.5%; 1/198), and Trypanosoma sp. (7%; 14/198). None of the targeted viral genes were detected. These pathogens were found in Gabonese rodents, mainly Lophuromys sp., Lemniscomys striatus and Praomys sp. We also identified new genotypes: Candidatus Bartonella gabonensis and Uncultured Anaplasma spp. This study shows that rodents in Gabon harbor some human pathogenic bacteria and protozoans. It is necessary to determine whether the identified microorganisms are capable of undergoing zoonotic transmission from rodents to humans and if they may be responsible for human cases of febrile disease of unknown etiology in Gabon.

Highlights

For several decades, rodents have been recognized as reservoirs or hosts carrying zoonotic pathogens [1,2,3,4] that can have very dramatic impacts on the economy and public health [2]
All rodents were found negative for all viral pathogens screened in the spleen by conventional PCR and qPCR, including Hantavirus spp., Mammarenavirus spp., Flavivirus, Paramyxovirus, Lymphocytic choriomeningitis mammarenavirus (LCMV) and Zika virus (ZIKV)
All rodents were found negative by qPCR on tissues for several bacteria and protozoa, Borrelia sp, Leishmania sp, Mycoplasma sp, Orientia sp, Occidentia sp, Streptobacillus moniliformis, Rickettsia sp and Yersinia pestis

Summary

Introduction

Rodents have been recognized as reservoirs or hosts carrying zoonotic pathogens [1,2,3,4] that can have very dramatic impacts on the economy and public health [2]. These zoonoses include the plague [5, 6], Lassa hemorrhagic fever (LHF) [7], and hemorrhagic fever with renal syndrome [8]. Leptospirosis cases can be misdiagnosed as dengue or malaria infection because of the similarity of the initial symptoms [12]. Such misdiagnosis is especially frequent in countries of sub-Saharan Africa, where access to the necessary diagnostic tools is limited [13, 14]

Methods

Results

Conclusion