전남지역 내 설치류 매개 감염병 병원체 (아나플라즈마증, 쯔쯔가무시증, 렙토스피라증)의 분자 역학

Abstract

Background: High incidence rate of rodent-borne infectious diseases at the Jeollanam-do might be due to the high average temperature of the region with the provision of the proper conditions to inhabit rodents and ticks parasitized with the rodents. Therefore, this study was conducted to investigate the detection rate of various bacterial diseases of rodents.

Experimental method: The existence of genes relating to pathogens, such as Anaplasma phagocytophilum(AP), Orientia tsutusgamushi(OT), Leptospira interrogans(LI), which occur anaplasmosis, scrub typhus and leptospirosis, was examined with the nested PCR and real-time PCR in the blood, kidney and spleen of the rodents captured. The detection rate of the pathogens compared by the month and place of capture, and subsequently the effect of inhibition environment of the captured rodents on the existence of the pathogens was investigated. Additionally, the comparative analysis of nucleotide sequences in the pathogens was conducted to identify the phylogenetic characteristics of the genes.

Results: Twenty-one rodents were captured in traps installed for this study. All of the rodents were identified to Apodemus agrarius (AA). There were no significant differences between months and places of the AA captured. Through the analysis of the genes existed in the blood, kidney and spleen tissues, significant differences were found in the prevalence of each pathogen by clinical specimens. Detection of species specific genes [A. phagocytophilum (AP), O. tsutusgamushi (OT) and L. interrogans (LI)] indicated that human can be infected by the pathogens, resulting in having a pathogenic potential of anaplasmosis, scrub typhus and leptospirosis. The comparative analysis of nucleotide sequences obtained from the genes of the AA captured revealed that AP has groEL and ankA, which have a high homology with the conventional genotype identified until a recent date. The genotype of OT analyzed on the basis of 56 kDa gene was confirmed to Pajoo for 7 AA, Yeongwol for 1 and Boryong for 1. For the LI, serovars of Lai and Hardjo-prajitno were identified in the genes of IS1500 and rpoB, respectively. The total detection rate of LI showed higher than that of AP and OT, thus the prevalence of leptospirosis in the Jeollanam-do province is expected to increase in near future.

Conclusion: When the detection rates of AP, OT and LI were compared, the infection rate of LI was higher than that of AP and OT. Therefore, further researches on the prevalences of ticks, patients having a LI as a zoonotic pathogen, and AA are necessary to understand clearly the phylogenetic characteristics of genotype of the pathogens occurring rodent-borne infectious diseases.