Presence of pathogenic Borrelia burgdorferi sensu lato in ticks and rodents in Zhejiang, south-east China

Abstract

A molecular epidemiological survey was conducted to investigate the presence of pathogenic Borrelia burgdorferi sensu lato (s.l.) species in the forest areas of Zhejiang province, south-east China. A total of 182 ticks of 6 species and 200 rodents of 8 species were collected and individually examined for the presence of B. burgdorferi s.l. DNA by nested PCR targeting the 5S-23S rRNA intergenic spacer. Forty-one ticks of four species, Haemaphysalis concinna, Haemaphysalis longicornis, Rhipicephalus microplus and Haemaphysalis warburconi, were infected with B. burgdorferi s.l., with an overall infection rate of 23 %. Sixteen rodents of four species, Nivivener confucianus, Nivivener coxingi, Apodemus sylvaticus and Rattus losea, were positive for B. burgdorferi s.l., with an overall prevalence of 8 %. MseI RFLP analysis and sequence analysis of the positive PCR products showed that Borrelia spirochaetes in specimens consisted of Borrelia garinii, Borrelia afzelii and Borrelia valaisiana-related group. Forty (98 %) of the B. burgdorferi s.l.-positive ticks were infected with B. garinii and one (2 %) was infected with B. afzelii. Twelve (75 %) of the positive rodents were infected with B. garinii and four (25 %) were infected with the Borrelia spirochaete belonging to B. valaisiana-related group. INTRODUCTIONLyme disease (LD) is a multi-organ infection caused by certain spirochaetes in the Borrelia burgdorferi sensu lato (s.l.) species complex (Steere et al., 1983;Hengge et al., 2003). The complex is considered to comprise at least 12 different genospecies to date (Masuzawa et al., 2001;Richter et al., 2006;Wang et al., 1999). Among them, Borrelia burgdorferi sensu stricto (s.s.), Borrelia garinii and Borrelia afzelii are the major aetological agents of human LD (Baranton et al., 1992;Wang et al., 1999). In addition, Borrelia bissettii (Picken et al., 1996), Borrelia valaisiana (Rijpkema et al., 1997), Borrelia lusitaniae (Collares-Pereira et al., 2004) and Borrelia spielmanii (Foldvari et al., 2005) are considered to be potentially pathogenic to humans. B. burgdorferi s.l. is mainly maintained in natural foci through the transmission cycles of competent tick vectors and vertebrate reservoirs Burgdorfer et al., 1991;Hengge et al., 2003). Humans accidentally enter this cycle and represent dead-end hosts for the agent (Hengge et al., 2003).LD was first documented in north-east China in 1986 (Ai et al., 1987). One typical case of human lyme borreliosis was reported in Zhejiang province of south-east China (Cheng et al., 1992), where a good many of the popular tourist destinations and the well-known tea gardens are located. Antibody to B. burgdorferi s.l. was also detected in serum samples from some residents living in the forest areas of this province (Zhang et al., 1997(Zhang et al., , 2001). However, only Borrelia sincica and B. valaisiana-related strains, which are not known to be pathogenic to humans, have been isolated in this area to date (Masuzawa et al., 2001). Furthermore, no information is available concerni...

Prevalence of Anaplasma phagocytophilum in ruminants, rodents and ticks in Gansu, north-western China

“…These data suggest that Apodemus agrarius may contribute to the maintenance of a natural cycle of Anaplasma phagocytophilum in China. Apodemus agrarius is distributed over an extensive area in mainland China and is also known to be a major reservoir host for B. burgdorferi sensu lato (Chu et al, 2008). Our results further demonstrate the role of Apodemus agrarius as a reservoir of Anaplasma phagocytophilum in the Gannan Tibetan Autonomous Prefecture in north-western China.…”

Prevalence of Tick Borne Pathogens in Horses from Italy

“…and Leptospira spp., serum samples were also tested using the SNAP® 4Dx test kit (IDEXX Laboratories, Westbrook, ME, U.S.A.), a qualitative in-clinic rapid ELISA test that specifically detects antibodies against the invariable domain IR6 of the variable surface antigen VlsE of B.burgdorferi, commonly known as the "C6 antigen". DNA was extracted from the blood samples containing EDTA using the QIAamp DNA Mini Kit (QIAGEN S.p.A., Milan, Italy) in accordance with the manufacturer's guidelines and then subjected to PCR assays previously described in veterinary literature: A. phagocytophilum DNA was detected using a nested-PCR protocol that amplifies a specific 928 bp fragment of the 16S-rRNA gene as described by Barlough et al [2]; a specific nested PCR protocol [12] amplifying a 226-266 bp fragment (depending on the strains) encompassing the 5S-23S intergenic spacer region of the rRNA was used for B. burddorferi DNA detection; in order to identify the presence of babesial parasite DNA, PCR was performed using the CRYPTO F [22] and RLB-R2 [8] that amplifies a fragment of the 18S-rRNA approximately 800 bp in size.…”

The presence of Borrelia valaisiana-related genospecies in ticks and a rodent in Taiwan

“…In conclusion, Borrelia strains obtained in Taiwan appear to be genetically similar to the B. valaisiana-related group found in eastern Asia and southwestern and southeastern China (Masuzawa et al, 2004;Chu et al, 2008aChu et al, , 2008bChao et al, 2010). We provide the first evidence of B. valaisiana-related genospecies in vector ticks and a rodent host, suggesting that B. valaisiana-related strains circulate between rodent reservoir hosts and tick vectors in Taiwan.…”