Investigation of Borrelia burgdorferi carried in rodents in three cities/counties of Yunnan Province
Objective To investigate the carrier status of Borrelia burgdorferi in rodents in three counties of Yunnan and to identify influencing factors,to provide a scientific basis for effective control and prevention of human Lyme disease.Methods From July to August 2019,rodents were collected by night trapping method from 16 natural villages across Mile City,Mangshi City,and Lianghe County in Yunnan.Spleen tissue samples were collected,and DNA was extracted.The target fragment of Borrelia burgdorferi 5S-23S rRNA gene was amplified by nested PCR,and positive products were sequenced.The sequences were homologous compared and a phylogenetic tree was constructed.The Chi-square test or Fisher's exact probability method was applied in R software to analyze the presence of Borrelia burgdorferi in rodents in different regions,habitats,species,genders,ages,and flea statuses.Results A total of 491 spleen samples were tested,from which 11 amplified the target gene fragment of Borrelia burgdorferi,with a carriage rate of 2.24%.Among them,the carriage rates in Mangshi City and Lianghe County were 1.58%and 3.43%,respectively,while no B.burgdorferi was detected in Mile City.Positive cases of Borrelia burgdorferi were detected in 4 species of rodents from 3 orders,3 families,and 3 genera:Crocidura attenuata(9.09%,1/11),Rattus tanezumi(3.27%,8/245),Rattus nitidus(16.67%,1/6),and Tupaia belangeri(7.69%,1/13).There was a statistically significant difference in Borrelia burgdorferi carried among rodents from different habitats(P<0.05),with the highest carrying rate(7.29%)found in rodents from bushes.No significant differences were observed in carriage rates across different regions,species,genders,ages,or flea statuses(all P>0.05).Sequence alignment analysis revealed that the gene sequences of 11 positive samples showed 100%homology with some of the 5S-23S rRNA gene sequences of Borrelia burgdorferi included in GenBank.Evolutionary analysis showed that they clustered in the same branch as Borrelia valaisiana.Conclusions The carriage rate of Borrelia valaisiana in rodents from Mangshi City and Lianghe County in Yunnan Province is low,but there remains a potential risk to human health.No Borrelia burgdorferi was detected in rodents from Mile City.
Borrelia burgdorferiLyme diseasegenotyperodentsYunnan Province
万方数据
维普
