ABSTRACT
Objective:To investigate the infection of spotted fever group Rickettsiae (SFGR) and Rickettsia mooseri ( R.mooseri) of wild rodents in the field of plague foci in Western Yunnan. Methods:The DNA of liver samples of 2 512 wild rodents captured from the plague foci in Lianghe County, Jianchuan County and Yulong County in Western Yunnan from 2015 to 2016 was extracted by magnetic bead method, and the heat shock protein groEL gene primers were used for nested PCR amplification. Gene sequence splicing and Blast homology comparison were performed using DNAStar 7.1 software and GenBank of the National Center for Biotechnology Information (NCBI) of the United States, respectively, and DNAStar 7.1 and MEGA 6.0 softwares were used to construct phylogenetic trees.Results:The wild rodents infected with SFGR were Mus pahari, Rattus steini, Crocidura attenuata and Suncus murinus (one for each), with a total infection rate of 0.16% (4/2 512); no R.mooseri infection was detected. The SFGR infection rates of wild rodents in the plague foci of Lianghe County and Jianchuan County were 0.49% (3/611) and 0.10% (1/1 029), respectively; no SFGR infection was detected in the wild rodents in the plague foci of Yulong County. The homology analysis showed that the homology between SFGR positive samples and reference sequences was 95.45%-100.00%; some of the groEL gene sequences were highly similar among the four positive samples, and the homology was 89.60%-97.40%. Sequence evolution analysis showed that the sequences of three SFGR positive samples from the plague focus in Lianghe County were clustered in the same branch, and the homology reached 94.40%-97.40%; one positive sample sequence from the plague focus in Jianchuan County was clustered in one branch. Conclusion:SFGR infection rate of wild rodents in the field of plague foci in Western Yunnan is low, and no R.mooseri infection is found.
ABSTRACT
Spotted fever caused by spotted fever group rickettsiae (SFGR) is found throughout China. During 2007—2008, 28 human SFGR isolates and 34 rat SFGR isolates including 15 isolates from <i>Rattus fulvescens</i>, 5 isolates from <i>R.edwardsi</i>, 7 isolates from <i>Callosciurus erythraeus roberti</i> and 7 isolates from <i>Dremomys rufigenis</i>) were obtained from L929 cell culture. Previous research indicated that the 62 strains of SFGR mentioned above shared not only the same serophenotype but also 100% of identity sequences of 16S rRNA, <i>gltA</i>, <i>ompA</i>, <i>groEL</i> and 17KD, which enabled us to apply multispacer typing (MST) to the 62 SFGR isolates in the study. Six primer pairs, which were used for typing of <i>Rickettsia rickettsii</i> and <i>Rickettsia conorii</i>, were chosen, and the results exhibited greater nucleotide polymorphisms among the 62 isolates tested. A total of 48 distinct genotypes were identified. The dominant genotype, represented by h3 isolates, accounted for 21.7% (13/60) of the isolates tested, and the remaining 47 genotypes were all unique. Phylogenetic analysis showed that all the 48 genotypes could be classified in the same clade, while the genetically related strain, <i>R.heilongjiangensis</i>, was close but not the same as the cluster. We concluded that the genetically diverse of spotted fever group rickettsiae strains are endemic in Chengmai County, Hainan Province, China.
ABSTRACT
Spotted fever caused by spotted fever group rickettsiae (SFGR) is found throughout China. During 2007–2008, 28 human SFGR isolates and 34 rat SFGR isolates including 15 isolates from <i>Rattus fulvescens</i>, 5 isolates from <i>R. edwardsi</i>, 7 isolates from <i>Callosciurus erythraeus roberti</i> and 7 isolates from <i>Dremomys rufigenis</i>) were obtained from L929 cell culture. Previous research indicated that the 62 strains of SFGR mentioned above shared not only the same serophenotype but also 100% of identity sequences of 16S rRNA, <i>gltA</i>, <i>ompA</i>, <i>groEL</i> and 17KD, which enabled us to apply multispacer typing (MST) to the 62 SFGR isolates in the study. Six primer pairs, which were used for typing of <i>Rickettsia rickettsii</i> and <i>Rickettsia conorii</i>, were chosen, and the results exhibited greater nucleotide polymorphisms among the 62 isolates tested. A total of 48 distinct genotypes were identified. The dominant genotype, represented by h3 isolates, accounted for 21.7% (13/60) of the isolates tested, and the remaining 47 genotypes were all unique. Phylogenetic analysis showed that all the 48 genotypes could be classified in the same clade, while the genetically related strain, <i>R. heilongjiangensis</i>, was close but not the same as the cluster. We concluded that the genetically diverse of spotted fever group rickettsiae strains are endemic in Chengmai County, Hainan Province, China.
ABSTRACT
Objective To monitor the co-infection status of Borrelia burgdorferi sensu lato (R.b.s.1) and spotted fever group Rickettsia (SFGR) in tourist areas of Heilongjiang province.Methods Polymerase chain reaction (PCR) was used to detect the 5S-23S rRNA intergenic spacer of B.b.s.1 and ompA of SFGR in ticks,dynamically collected from tourist areas of Heilongjiang province in 2010.Amplification products from positive ticks were sequenced,and phylogenetic analysis was conducted by Mega 5.0 software package.Results 849 ticks were collected from two tourist points,with the dominant ticks in Tiger Mountain and Jingpo Lake were Ixodes persulcatus and Haemaphysalis concinna.Regarding the Ixodes persulcatus from Tiger Mountain,the infection rates of B.b.s.1 and SFGR were 26.15％ and 10.05％.The infection rate of SFGR was 13.33％ in Haemaphysalis concinna and the B.b.s.1 was tndiscovered in the same ticks from Jingpo Lake.However,the co-infection could only be detected in Ixodes persulcatus of both tourist areas.Surveillance data showed that the major ticks were more likely to be appeared in July at Tiger Mountain and in June at Jingpo Lake.Data from the sequence analysis on B.b.s.1 showed that the B.b.s.1 in tourist areas could be classified into three different genotypes,other than B.garinii and B.afzelii.We first detected B.valaisiana-like group genotype in northeast of China.Results from the sequence analysis of SFGR positive products showed that the two DNA sequences of newly detected agents were completely the same as Rickettsia sp.HL-93 which was detected in Hulin and Rickettsia sp.H820 found in northeast,China.Conclusion The co-infection of B.b.s.1 and SFGR was detected in ticks from the tourist areas of Heilongjiang province,and data from the sequencing of specific fragment showed that various kinds of genotypes existed in this area.However; the rates of co-infectionitis-different according to environment,time and population that contributed to the kinds of and the index of ticks existed in the surveys points,also the infection rate of the ticks was studied.
ABSTRACT
Objective The present study was conducted to investigate the infection of Lyme disease, Spotted fever, Ehrlichiosis (anaplasmosisin) in wild animals and ticks in the mountain areas of Zhejiang province. Methods Nested polymerase chain reaction was used to amplify specific DNA sequences of Lyme spirochetes, Spotted fever group rickettsiae, Ehrlichia (anaplasma) from samples of mice and ticks. Results 14 positive samples were identified from 121 mice and 105 groups of ticks. Among mice samples, one positive 5S-23S rDNA intergenic spacer of Borreia burgdorferi and two 5' fragments of Ehrlichia (anaplasma) 16S rDNA were obtained. 11 positive results were detected from tick samples including three 5S-23S rDNA intergenic spacer regions of Borreia burgdorferi and eight 5' fragments of Spotted fever group rickettsiae outer member protein A gene. One group of adult ticks, Haemaphysalis longicornis, which had been collected from eastern mountain area were detected to have co-infected with Lyme spirochetes and Spotted fever group rickettsiae. The positive sequences of 5S-23S rDNA intergenic spacer and ompA gene were tested and analyzed as Lyme spirochetes while rickettsia which was closely related to Borrelia valaisiana and R. massilliae. Conclusion This was the first report about co-infection of Lyme spirochetes and Spotted fever group rickettsiae found in the same group of adult Haemaphysalis longicornis. It is very important to strengthen the surveillance program on tick-borne infectious disease and their pathogenic in vectors, wild animals and targeted high risk groups and to differentiate the clinical manifestation and diagnosis to extend the knowledge of tick-borne infectious diseases in Zhejiang.