Establishment of multiple locus variable-number tandem repeat analysis assay for genotyping of Borrelia burgdorferi sensu lato detected in China / 生物医学与环境科学（英文）

<p><b>OBJECTIVE</b>Human Lyme Borreliosis (LB), which is caused by Borrelia burgdorferi sensu lato (B. burgdorferi), has been identified as a major arthropod-borne infectious disease in China. We aimed to develop a multiple locus variable-number tandem repeat (VNTR) analysis (MLVA) assay for the genotyping of Borrelia burgdorferi strains detected in China.</p><p><b>METHODS</b>B. garinii PBi complete 904.246 kb chromosome and two plasmids (cp26 and lp54) were screened by using Tandem Repeats Finder program for getting potential VNTR loci, the potential VNTR loci were analyzed and identified with PCR and the VNTR loci data were analyzed and MLVA clustering tree were constrcted by using the categorical coefficient and the unweighted pair-group method with arithmetic means (UPGMA).</p><p><b>RESULTS</b>We identified 5 new VNTR loci through analyzing 47 potential VNTR loci. We used the MLVA protocol to analyse 101 B. burgdorferi strains detected in China and finally identified 51 unique genotypes in 4 major clusters including B. burgdorferi sensu stricto (B.b.s.s), B. garinii, B. afzelii, and B. valaisiana, consistent with the current MLSA phylogeny studies. The allele numbers of VNTR-1, VNTR-2, VNTR-3, VNTR-4, and VNTR-5 were 7, 3, 9, 7, and 6. The Hunter-Gaston index (HGI) of five VNTR loci were 0.79, 0.22, 0.77, 0.71, and 0.67, respectively. The combined HGI of five VNTR loci was 0.96. Clustering of the strains of Xinjiang, Inner Mongolia and Heilongjiang was confirmed, and this situation was consistent with the close geographical distribution of those provinces.</p><p><b>CONCLUSION</b>The MLVA protocol esytablished in this study is easy and can show strains' phylogenetic relationships to distinguish the strains of Borrelia species. It is useful for further phylogenetic and epidemiological analyses of Borrelia strains.</p>

First record of Borrelia burgdorferi B31 strain in Dermacentor nitens ticks in the northern region of Parana (Brazil)

The aim of this study was to investigate the presence of DNA of Borrelia burgdorferi sensu lato (s.l.) in ticks that feed on horses used for animal traction in rural Jataizinho, Parana, Brazil. Between February and June 2008, a total of 224 ticks was collected of which 75% were identified as Dermacentor nitens and 25% as Amblyomma cajenense. To amplify B. burgdorferi s.l. DNA, the intergenic space region (ISR) between the 5S (rrf) 23S (rrl) rRNA genes was used as targets for nested-PCR. Two ticks of the D. nitens species were positive for B. burgdorferi s.l. Both species showed a fragment of 184 bp, but the sequencing revealed 99.9% homology with the B. burgdorferi sensu stricto (s.s.) strain B31. These results showed, for the first time, the presence of spirochete DNA infecting ticks that parasitize horses used for animal traction, in the rural municipality mentioned. In conclusion, this study opens up promising prospects for determining the infection rate of B. burgdorferi s.s. genospecies or other species in the equine population, as well as the impact of the infection rate on Lyme disease in the state of Parana.

Dynamic investigation on the co-infection status of two pathogens in ticks from tourist point in Heilongjiang province / 中华流行病学杂志

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.

Isolation and identification of Borrelia burgdorferi sensu lato from ticks in six provinces in China / 中华流行病学杂志

Objective To understand the carrying status of Borrelia burgdorferi in ticks from the mountain areas from six representative provinces, including Jilin, Shanxi, Gansu, Qinghai,Guizhou and Hunan in China. Methods Flagging and trapping methods were used to collect ticks in forest area and culture medium was used to isolate the pathogen. Nested-PCR was used to detect the gem-carrying rate of ticks. Results More than 2200 ticks from six representative provinces were collected and 1000 ticks were used to isolate the pathogen. 13 Lyme disease spirochetes from ixodes persulcatus in Changbai, Jilin province and 9 Lyme disease spirochetes from ixodes granulatus in Daozhen, Guizhou province were identified. There were 1255 ticks used for PCR testing. Specific fragments of the Borrelia burgdorferi in ticks were found from the six representative provinces in China. The carrier rate was higher in Jilin (Changbai 27.08%, Tonghua 20.41% ), Qinghai (Huzhu 25.06%, Huangnan 21.11%)and Guizhou (Daozhen 25.63% ), than in Shanxi (Yuanqu 4.72%,Jiaocheng 3.64% ). Result from the sequence analysis showed that the genotype belong to Borrelia garinii in Jilin, Qinghai, Gansu, Shanxi provinces but Borrelia valaisiana in Guizhou and Hunan provinces. Conclusion Our data showed that there existed Lyme disease spirochetes in all the six representative provinces in China, but the carriying rates of ticks were different. Borrelia garinii was found in Shanxi province, and Borrelia valaisiana in Hunan province.