Hantavirus RNA Prevalence in Myomorph Rodents on Bolshoy Ussuriysky Island at the Sino-Russian Border.

OBJECTIVE: To understand the distribution and infection status of hantavirus in Myomorph rodents on Bolshoy Ussuriysky Island (Heixiazi Island) at the Sino-Russian border, and to provide data for the safe development and utilization of Bolshoy Ussuriysky Island. METHODS: In 2013 and 2014, Myomorph rodents were trapped on Bolshoy Ussuriysky Island. Total RNA was extracted from rodent tissue, and it was screened for hantavirus RNA by using reverse transcription-polymerase chain reaction. Univariate and multivariate nonconditional logistic regression analysis was used to analyze the RNA prevalence rates in eight species of rodents, in relation to species, sex, age, habitat, and season. In addition, PCR amplicons were sequenced and phylogenetic analysis was performed by using Mega 5.1 software. RESULTS: Six hundred forty-four rodents belonging to three orders, five families, and eight genera were trapped. Fifty-two rodents were infected with hantavirus, and the rate of RNA detection was 8.07%. The infection rates of rodents in different habitats (χ2 = 14.853, p < 0.05) and different seasons (χ2 = 16.990, p < 0.05) showed significant differences. A logistic regression analysis showed that habitat and trapping season were risk factors of hantavirus infection (p < 0.05). Phylogenetic analysis showed that the gene sequences of positive samples were Hantaan virus and Khabarovsk virus. CONCLUSION: There are two types of hantaviruses, such as HTNV (in Apodemus agrarius, Clethrionomys rutilus, Microtus fortis, Rattus norvegicus) and KHAV (in C. rutilus), among the rodents on Bolshoy Ussuriysky Island, and season and habitat are risk factors of hantavirus infection.

Complete mitochondrial genome and phylogenetic analysis of Ixodes persulcatus (taiga tick).

Ixodes persulcatus is a species of hard tick which is a predominant tick species that spreads a wide array of serious human and animal pathogens. Here, we first assemble the complete mitogenome of I. persulcatus of China. The total length of the mitogenome was 14,539 bp included 36 genes and with a mitogenome structure similar to other ticks. Phylogenetic tree was constructed based on the complete mitogenome of I. persulcatus and closely related 19 species ticks to assess their phylogenic relationship and evolution. We also analyze the differences between the mitogenomes of I. persulcatus of Japan and China. The complete mitogenome data would be useful for further study of I. persulcatus.

High prevalence and genetic heterogeneity of rodent-borne Bartonella species on Heixiazi Island, China.

We performed genetic analysis of Bartonella isolates from rodent populations from Heixiazi Island in northeast China. Animals were captured at four sites representing grassland and brushwood habitats in 2011 and examined for the prevalence and genetic diversity of Bartonella species, their relationship to their hosts, and geographic distribution. A high prevalence (57.7%) and a high diversity (14 unique genotypes which belonged to 8 clades) of Bartonella spp. were detected from 71 rodents comprising 5 species and 4 genera from 3 rodent families. Forty-one Bartonella isolates were recovered and identified, including B. taylorii, B. japonica, B. coopersplainsensis, B. grahamii, B. washoensis subsp. cynomysii, B. doshiae, and two novel Bartonella species, by sequencing of four genes (gltA, the 16S rRNA gene, ftsZ, and rpoB). The isolates of B. taylorii and B. grahamii were the most prevalent and exhibited genetic difference from isolates identified elsewhere. Several isolates clustered with strains from Japan and far-eastern Russia; strains isolated from the same host typically were found within the same cluster. Species descriptions are provided for Bartonella heixiaziensis sp. nov. and B. fuyuanensis sp. nov.

[The infection status of Leptospira in rodents on the Heixiazi island of Heilongjiang province, China,in 2011].

OBJECTIVE: To study the infection status of Leptospira in rodents on Heixiazi island Heilongjiang province in 2011. METHODS: A total of 356 rodents were captured by night trap on the Heixiazi island from April to October 2011. The kidney tissue samples were collected by asepsis operation and the genomic DNA were extracted from them. Leptospira strains were confirmed by polymerase chain reaction(PCR) amplification of the 482 bp 23 S rDNA gene. Fifteen PCR products selected by the month were purified and sequenced by the methods of Sanger dideoxy, the sequences then compared with other Leptospira strains in Genebank, and phylogenetic analyses were drafted by software Mega 4.0. RESULTS: Among 356 rodents, the dominant species were Clethrionomys rutilus (39.3%, 140/356) and Apodemus agrarius (36.0%, 128/356). The infection rate of Leptospira was 11.0%, with 39 rodent samples detected positive. All the rodent species were infected except for Rattus norvegicus. The infection rate was 9.4% (12/128) in Apodemus agrarius, 12.9%(18/140) in Clethrionomys rutilus, 10.8%(7/65) in Microtus fortis Buchner. No significant difference was found between the infection rate and the species of rodents by chi square test(χ(2) = 1.92, P > 0.05). Among months, the infection rate was 5.6% (4/72) in May, 8.8% (5/57) in June, 12.8% (5/39) in July, 9.8% (5/51) in August, 33.3% (11/33) in September, 22.5% (9/40) in October,but no infection in April. There was significant difference in infection in different months (χ(2) = 32.92, P < 0.05). All the Leptospira in rodents on the Heixiazi island were in the same phylogenetic branch with a high similarity of 97.1%-99.6%, close with the Australia strain U90865 by the similarity above 96.3%. CONCLUSION: Leptospira is probably prevalent in rodents on the Heixiazi island, and the phylogene of the strains were similar. The infection rate in rodents was significantly different in months but not in hosts.