Animals ; Ehrlichia/isolation & purification* ; Ehrlichiosis/veterinary* ; Prevalence ; Rodent Diseases/microbiology* ; Rodentia ; Species Specificity

Objective: To understand the genotype of the Yersinia (Y.) pestis strains isolated from Heqing county, Yunnan province in 2017 and provide evidence for the prevention and control of plague in this area. Methods: Ten Y. pestis strains isolated from Heqing were typed by the detections of different region (DFR) and clustered regularly interspaced short palindromic repeats (CRISPRs) as well as multiple-locus variable-number tandem repeat analysis (MLVA). And the results were compared with those of the 93 Y. pestis strains from the adjacent plague foci of Heqing obtained from the established database for clustering analysis. Results: The results showed that Heqing strains had the same type of DFR (Genomovar 05) and CRISPRs (Cluster Ca7, Type 22) with isolates from the plague focus in Lijiang. Heqing strains and Lijiang strains were in the same cluster in MST and only VNTR loci N2117 and M23 of Heqing strains were different from that of Lijiang strains. Conclusion: The Y. pestis strains isolated from Heqing in 2017 were highly homogenous with the strains isolated from wild rodents in plague focus in Lijiang, and Heqing plague might be the result of further southward spread of Lijiang plague.
Animals ; China/epidemiology* ; Epidemiological Monitoring ; Genotype ; Minisatellite Repeats ; Molecular Typing ; Plague/microbiology* ; Rodentia/microbiology* ; Yersinia pestis/pathogenicity*

OBJECTIVETo investigate the impact of impoundment and active public health interventions on rodent populations and rodent-borne diseases in the Three Gorges reservoir region from 1997 to 2012.

METHODSSurveillance data from 1997 to 2012 were extracted from the Public Health Surveillance System of The Three Gorges established in 1997. Temporal changes in the incidences of hemorrhagic fever with renal syndrome (HFRS) and leptospirosis, rodent density, pathogen-carrying rates, and their correlations were analyzed.

RESULTSThe average indoor and outdoor rodent densities decreased overall from 1997 to 2012. The average densities decreased by 47.72% (from 4.38% to 2.29%) and 39.68% (from 4.41% to 2.66%), respectively, after impoundment (2003-2012) compared with before impoundment (1997-2002). The average annual incidence rates of HFRS and leptospirosis were 0.29/100,000 and 0.52/100,000, respectively, and decreased by 85.74% (from 0.68/100,000 to 0.10/100,000) and 95.73% (from 1.47/100,000 to 0.065/100,000), respectively, after impoundment compared with before impoundment. Incidences of HFRS and leptospirosis appear to be positively correlated with rodent density in the reservoir area.

CONCLUSIONThis study demonstrated that rodent density and incidences of rodent-borne diseases decreased and were maintained at low levels during construction of the Three Gorges dam. Measures that reduce rodent population densities could be effective in controlling rodent-borne diseases during large-scale hydraulic engineering construction.

Animal Distribution ; Animals ; China ; epidemiology ; Disease Reservoirs ; Hantavirus Infections ; epidemiology ; veterinary ; Leptospirosis ; epidemiology ; virology ; Population Density ; Rodent Diseases ; epidemiology ; microbiology ; virology ; Rodentia ; Seasons ; Time Factors ; Water Supply ; Zoonoses

A total of 9,281 larval chigger mites were collected from small mammals captured at Hwaseong-gun, Gyeonggi-do (Province) (2,754 mites from 30 small mammals), Asan city, Chungcheongnam-do (3,358 mites from 48 mammals), and Jangseong-gun, Jeollanam-do (3,169 for 62 mammals) from April-November 2009 in the Republic of Korea (= Korea) and were identified to species. Leptotrombidium pallidum was the predominant species in Hwaseong (95.8%) and Asan (61.2%), while Leptotrombidium scutellare was the predominant species collected from Jangseong (80.1%). Overall, larval chigger mite indices decreased from April (27.3) to June (4.9), then increased in September (95.2) and to a high level in November (169.3). These data suggest that L. pallidum and L. scutellare are the primary vectors of scrub typhus throughout their range in Korea. While other species of larval chigger mites were also collected with some implications in the transmission of Orientia tsutsugamushi, they only accounted for 11.2% of all larval chigger mites collected from small mammals.
Animals ; Arachnid Vectors ; Larva/*microbiology ; Orientia tsutsugamushi/*isolation & purification ; Republic of Korea ; Rodentia ; Scrub Typhus/*microbiology ; Trombiculidae/*classification/*microbiology

OBJECTIVE: To investigate the infection in spotted fever group Rickettsiae (SFGR) in wild rodents from Heilongjiang, China. METHODS: Polymerase chain reaction (PCR) was used to detect the OmpA gene of SFGR in rodents collected in Heilongjiang. The PCR products amplified from rodent specimens were sequenced and compared with the corresponding part of the sequences deposited in the GenBank. Phylogenetic trees were constructed with Mega 5.0 software. RESULTS: A total of 514 rodents were collected from Heilongjiang during 2009-2011 and 11 species were included. The infection rate of SFGR in the rodents was 9.3% (95% CI: 7.1%-12.2%). Statistical analysis showed a significant difference in different areas of Heilongjiang (P=0.023). The highest prevalence was observed in Mudanjing area (12.42%). There were significant differences in different species of rodents (P=0.002). The infection rate of SFGR determined in Clethrionomys rufocanus was the highest (22.1%). Sequence analysis revealed SFGR belonged to R.heilongjiangensis and a new unknown rickettsia genotype. CONCLUSION R.heilongjiangensis has been presented in rodents in Heilongjiang, and a new SFGR genotype different from other rickettsiae genotypes may exist in this area.
Animals ; China ; DNA, Bacterial ; genetics ; isolation & purification ; Forests ; Phylogeny ; Polymerase Chain Reaction ; Rats ; Rickettsia ; classification ; genetics ; isolation & purification ; Rickettsia Infections ; microbiology ; veterinary ; Rodentia ; microbiology ; Sequence Analysis

Animals ; Borrelia burgdorferi ; genetics ; China ; DNA, Bacterial ; genetics ; isolation & purification ; Rodentia ; microbiology ; Sequence Analysis, DNA

OBJECTIVETo analyze the genetic evolution and bacterial type changes of Yersinia enterocolitica in the Ningxia area between year 1984 and 2011.

METHODSA total of 296 strains of Yersinia enterocolitica was collected from diarrhea patients, pig, rodents, sheep and dogs between year 1984 and 2011. The serotype, biotype, ail, ystA, ystB, yadA, virF and other toxic genes were detected. The PFGE subtypes of serotype O:3 and O:9 strains and the cluster features were analyzed.

RESULTSOut of 296 Yersinia enterocolitica strains, pig was the main host, accounting for 65.20% (193/296), followed by rodents, accounting for 32.43% (96/296). Serotype and biotype had their own respective dominant types in different periods. During 1984 and 1985, 2 strains of serotype O:3 and 3 strains of serotype O:9 were isolated, all belonged to biotype 3. Because of lack of strains, there were no obvious dominant types found. Between 1997 and 1999, 177 strains of serotype O:9 Yersinia enterocolitica were isolated as the dominant strain; and there were 178 strains of biotype 2 Yersinia enterocolitica were found. During 2007 and 2011, 54 strains of serotype O:3 Yersinia enterocolitica were isolated as dominant strain; followed by 26 strains of serotype O:5. There were separately 44 and 59 strains of biotype 1A and biotype 3. The PCR test divided the 248 strains into 4 types, including pathogenic strains as type I (ail(+), ystA(+), ystB(-), yadA(+), virF(+)). The PFGE divided the serotype O:3 into 12 types, in which K6GN11C30021 and K6GN11C30012 were the dominant types, accounting for 63.64% (42/66). The serotype O:9 were divided into 14 types, in which K6GN11C90010, K6GN11C90008, K6GN11C30018 and K6GN11C90003 were the dominant types, accounting for 89.01% (162/182).

CONCLUSIONThe different serotypes of isolated strains in Ningxia district showed different dominant bacteria in different periods; while the biotypes also changed with serotypes. The Yersinia enterocolitica isolated from different years showed great variation.

Animals ; DNA, Bacterial ; genetics ; Dogs ; Electrophoresis, Gel, Pulsed-Field ; Genes, Bacterial ; Genetic Variation ; Humans ; Rodentia ; Sheep ; Swine ; Yersinia Infections ; microbiology ; Yersinia enterocolitica ; classification ; genetics ; isolation & purification

Comprehensive quarterly serosurveillance on scrub typhus in small mammals collected from military training sites located near the Demilitarized Zone (DMZ), northern Gyeonggi-do (Province), ROK was conducted to determine the potential rodent-borne and associated ectoparasite disease risks to military personnel. A total of 1,196 rodents and insectivores representing 8 species, Apodemus agrarius (87.3%, n = 1,044), Mus musculus (5.4%, n = 65), Crocidura lasiura (3.3%, n = 40), Microtus fortis (2.6%, n = 31), Micromys minutus (0.3%, n = 4), Tscherskia triton (0.3%, n = 4), Rattus norvegicus (0.3%, n = 4), and Myodes regulus (0.3%, n = 4) were assayed for the presence of antibodies to Orientia tsutsugamushi. O. tsutsugamushi antibodies were detected in 6 of 8 species and seroprevalence determined; A. agrarius (45.6%), M. musculus (23.1%), M. fortis (48.4%), M. minutus (50.0%), T. triton (50.0%), and R. norvegicus (25.0%). A total of 31,184 chigger mites collected from 508 rodents and insectivores were slide-mounted and 10 species belonging to 4 genera were identified. Leptotrombidium pallidum (53.4%) was the most frequently collected, followed by L. palpale (15.7%), Neotrombicula tamiyai (14.3%), L. orientale (10.7%), L. zetum (3.1%), Walchia fragilis (2.1%), and L. gemiticulum (0.8%), while the remaining 3 species, L. subintermedium, N. gardellai, and Euschoengastia koreaensis were rarely observed (prevalence < 10%). In contrast to previous surveys, higher chigger indices of the primary scrub typhus vectors, L. pallidum (165.4), L. orientale (45.0), and L. palpale (21.4), were observed during the spring season.
Animals ; Antibodies, Bacterial/immunology ; Arachnid Vectors/classification/*microbiology ; Disease Reservoirs/classification/microbiology/*parasitology ; Humans ; Military Facilities ; Orientia tsutsugamushi/*immunology/isolation & purification ; Republic of Korea ; Rodentia/classification/*immunology/microbiology/*parasitology ; Scrub Typhus/microbiology/*transmission/*veterinary ; Seroepidemiologic Studies ; Trombiculidae/classification/*microbiology

OBJECTIVETo investigate the prevalence of Anaplasma phagocytophilum in rodents from forest areas in northeastern China.

METHODSPCR amplification, followed by sequence analysis was carried out. The sequences of 16S rRNA and gltA gene fragment amplified from rodent specimens were compared with corresponding part of the sequences deposited in GenBank.

RESULTSA total number of 276 rodents were tested, including 102 in Jilin province, 61 in Helongjiang province and 113 in Inner Mongolia autonomous region. The positive rates were 8.82%, 1.64% and 0.00%, respectively. The infection rate in rodents infected by ticks was 11.30 times higher than that in rodents without ticks (P = 0.002). The S. A. phagocytophilum 16S rRNA sequences from rodents in Jilin and Heilongjiang were identical and differed in 3-5 bases compared with the corresponding parts of A. phagocytophilum from America, Sweden and Japan. Compared with the sequences registered in GenBank, the nucleotide sequence of gltA varied from 87%-97% and its deduced amino acid sequence changed from 84%-99%.

CONCLUSIONA. phagocytophilum infection was presented in rodents from Jilin and Heilongjiang province.

Amino Acid Sequence ; Anaplasma phagocytophilum ; genetics ; isolation & purification ; Animals ; Bacterial Proteins ; analysis ; Base Sequence ; China ; Ehrlichiosis ; veterinary ; RNA, Ribosomal, 16S ; analysis ; Rodentia ; microbiology ; Ticks ; Trees

OBJECTIVETo investigate rodents' natural infection of Orientia tsutsugamushi (Ot) in some areas of Inner Mongolia and Xinjiang, China.

METHODSDNAs were extracted from spleens of the captured mice and nested-polymerase chain reaction (nPCR) technique was used to detect the Ot-Sta56 gene. Six positive samples were sequenced and analyzed by Clustal X (5.0) and DNA Club software.

RESULTSA total of 90 rodents were captured in Inner Mongolia, and the overall prevalence of Ot was 6.67%. There was no significant difference in infection rates among the positive rodents species. 20 rodents were captured in Xinjiang, and the prevalence of Ot was 5.00%. The geographical difference in infection rates was not statistically significant between Inner Mongolia and Xinjiang. 9 rodents were captured in farmlands of Inner Mongolia and Xinjiang but there was no positive samples found. 101 rodents were captured in grasslands, and the prevalence of Ot was 6.93%. The Sta56 gene nucleotide sequence homology to Karp strain of N59 (from Microtus maximowiczii), N69 (from Cricetulus barabensis) and X33(from Cricetus cricetus) was 99%. The sequence homology to Taitung-2 strain and TW461 strain of N65 (from C. barabensis) was 94%, and the sequence homology to Taitung-2 strain and TW461 strain of N88(from Apodemus agrarius) was also 94%. The sequence homology to Oishi strain of N90 (from A. agrarius) was 96.00%.

CONCLUSIONOur findings indicated that infections of Ot did exist in rodents captured from Inner Mongolia and Xinjiang. The genotypes of Ot in Inner Mongolia and Xinjiang were quite complex, with some of them belonged to Karp type, and the others belonged to Taitung-2, TW461 and Oishi types which providing evidence for further investigation on the scrub typhus fuci in the two areas.

Animals ; China ; Geography ; Orientia tsutsugamushi ; genetics ; isolation & purification ; Polymerase Chain Reaction ; Rodentia ; microbiology ; Scrub Typhus