Molecular Surveillance for Vector-Borne Bacteria in Rodents and Tree Shrews of Peninsular Malaysia Oil Palm Plantations

Many human clinical cases attributed to vector-borne pathogens are underreported in Malaysia, especially in rural localities where healthcare infrastructures are lacking. Here, 217 small mammals, consisting of rodents and tree shrews, were trapped in oil palm plantations in the Peninsular Malaysia states of Johor and Perak. Species identification was performed using morphological and DNA barcoding analyses, and 203 small mammals were included in the detection of selected vector-borne bacteria. The DNA extracted from the spleens was examined for Orientia tsutsugamushi, Borrelia spp., Bartonella spp. and Rickettsia spp. using established PCR assays. The small mammals collected in this study included Rattus tanezumi R3 mitotype (n = 113), Rattus argentiventer (n = 24), Rattus tiomanicus (n = 22), Rattus exulans (n = 17), Rattus tanezumi sensu stricto (n = 1) and Tupaia glis (n = 40). Orientia tsutsugamushi, Borrelia spp. and Bartonella phoceensis were detected in the small mammals with the respective detection rates of 12.3%, 5.9% and 4.9%. Rickettsia spp., however, was not detected. This study encountered the presence of both Lyme disease and relapsing fever-related borreliae in small mammals collected from the oil palm plantation study sites. All three microorganisms (Orientia tsutsugamushi, Borrelia spp. and Bartonella phoceensis) were detected in the R. tanezumi R3 mitotype, suggesting that the species is a competent host for multiple microorganisms. Further investigations are warranted to elucidate the relationships between the ectoparasites, the small mammals and the respective pathogens.

Detection of Borrelia burgdorferi Sensu Lato and Relapsing Fever Borrelia in Feeding Ixodes Ticks and Rodents in Sarawak, Malaysia: New Geographical Records of Borrelia yangtzensis and Borrelia miyamotoi

Members of the Borrelia burgdorferi sensu lato (Bbsl) complex are etiological agents of Lyme disease (LD), and Borrelia miyamotoi is one of the relapsing fever Borrelia (RFB). Despite the serological evidence of LD in Malaysia, there has been no report from Sarawak, Malaysian Borneo. Thus, this study aimed to detect and characterize Borrelia in rodents and Ixodes ticks from primary forests and an oil palm (OP) plantation in Sarawak. Borrelia yangtzensis (a member of the Bbsl complex) was detected in 43.8% (14/32) of Ixodes granulatus; most of the positive ticks were from the OP plantation (13/14). Out of 56 rodents, B. yangtzensis was detected in four Rattus spp. from the OP plantation and B. miyamotoi was detected in one rodent, Sundamys muelleri, from the primary forest. Further, the positive samples of B. yangtzensis were randomly selected for multilocus sequence analysis (MLSA). The MLSA results of successfully amplified tick samples revealed a clustering with the sequences isolated from Japan and China. This study is the first evidence of B. miyamotoi, a known human pathogen in Malaysia, and B. yangtzensis, which is circulating in ticks and rodents in Sarawak, Malaysian Borneo, and presenting a new geographical record of the Borrelia spp.

Reclassification of Borrelia spp. Isolated in South Korea Using Multilocus Sequence Typing

Here, we used multilocus sequence typing (MLST) to evaluate 3 intergenic genes (16S rRNA, ospA, and 5S-23S IGS) in Borrelia isolated from South Korea to analyze the relationships between host, vector, and molecular background. We identified B. afzelii, B. yangtzensis, B. garinii, and B. bavariensis. This study is the first report for the identification of B. yangtzensis using MLST in South Korea.

Borrelia yangtzensis sp. nov., a rodent-associated species in Asia, is related to Borrelia valaisiana

Twenty-nine isolates of Lyme borreliosis (LB) group spirochaetes collected from ticks and rodents in China and Japan were included in a multilocus sequence analysis (MLSA). Using a different typing system, three of these strains had previously been identified as being divergent from other LB spirochaete species and the name 'Borrelia yangtze' sp. nov. was proposed. The data presented here confirm that the genetic distance, calculated using sequences of MLSA housekeeping genes, to other known LB group spirochaete species was < 95 % and to Borrelia valaisiana was 96.67 % (which represents the most closely related species within the group of LB spirochaetes). This and the fact that these strains are ecologically distinct from B. valaisiana (rodent-transmitted vs bird-transmitted) provide strong support for the validation of the proposed species status. We suggest the name Borrelia yangtzensis sp. nov. The type strain is Okinawa-CW62T ( = DSM 24625T = JCM 17189T).

Prevalence of Borrelia burgdorferi sensu lato in ticks from eastern China

To explore the tick distribution and prevalence of Borrelia in Zhejiang Province, we performed a survey in nine sites. A total of 447 adult ticks of 11 species were captured and the dominant tick species were Haemaphysalis longicornis and Ixodes sinensis and the abundance of tick species in different areas varied significantly. Overall, 4.70% of the ticks were polymerase chain reaction (PCR) positive for Borrelia. The average PCR positive rates were 5.19% for H. longicornis, 3.45% for Amblyomma testudinarium, 1.06% for I. sinensis, 5.00% for Rhipicephalus (Boophilus) microplus, and 19.44% for Ixodes granulatus, respectively. No Borrelia DNA was detected in Rhiphicephalus haemaphysaloides, Haemaphysalis yeni, Dermacentor taiwanensis, Haemaphysalis hystricis, Hyalomna asiaticum, and Ixodes ovatus. The prevalence of Borrelia was significantly different among tick species and the prevalence in I. granulatus was significantly higher than that in other tick species. Of note, experimentally confirmed vectors for B. burgdorferi s.l. including I. sinensis and I. granulatus were found in Zhejiang Province. Two species of B. burgdorferi s.l. exist in Zhejiang Province of which 12 sequences were most similar to the sequence of Borrelia garinii and nine sequences were most similar to the sequence of Borrelia valaisiana or Borrelia yangtze sp. nov.