Simultaneous detection of 7 important Rickettsiales pathogens by TaqMan-probe quantitative real-time PCR / 中华流行病学杂志

Objective: To establish and optimize a TaqMan-probe quantitative real-time PCR (qPCR) assay for the detection of 7 important Rickettsiales pathogens and simultaneous identification of the infection types. Methods: Based on the ompB gene of Rickettsia prowazekii, Rickettsia mooseri and spotted fever group rickettsiae, the groEL gene of Orientia tsutsugamushi, the 16S rRNA of Ehrlichia chaffeensis, the gltA gene of Anaplasma phagocytophilum and the com1 gene of Coxiella burnetii, we synthesized primers and TaqMan-probes and optimized the reaction system and reaction process to same solution. The sensitivity, specificity and reproducibility of this assay were evaluated and the assay was used for the detection of simulated and actual samples. Results: The Ct value of the standard curves of the 7 pathogens showed a good linear relationship with the number of DNA copies (all R2 >0.990 0), the minimum detection limit was 10 copies/μl, showing good specificity. In the 96 tick nucleic acid extracts, Coxiella burnetii was detected in 1 sampleand spotted fever group Rickettsiae was detected in 3 samples. In the 80 blood samples from patients with undefined febrile illness, Orientia tsutsugamushi was detected in 1 sample and spotted fever group rickettsiae was detected in 2 samples. Conclusions: In this study, based on the established TaqMan-probe qPCR assay, the reaction system and reaction condition of the 7 important pathogens of Rickettsiales were optimized to the same solution. This method overcomes the shortcomings of using different reaction systems and reaction conditions for different pathogens, which can precisely identify the species of 7 important pathogens of Rickettsiales in clinical sample detections and is important for the infection type identification and laboratory detection time reduction to facilitate precise treatment of the patients.

Molecular Detection of Tick-borne Pathogens in Ticks Collected from Hainan Island, China / 生物医学与环境科学（英文）

Pathogens like bacteria and protozoa, which affect human and animal health worldwide, can be transmitted by vectors like ticks. To investigate the epidemiology and genetic diversity of bacteria and protozoans carried by ticks in Chengmai county of Hainan province, China, 285 adult hard ticks belonging to two species [

Identification of Haemaphysalis longicomis and Rhipicephalus microplus / 中华流行病学杂志

Objective To establish a method combined morphology and molecular marker for identifying Haemaphysalis longicomis and Rhipicephalus microplus. Methods Ticks were collected from domestic animals and wild environment in epidemic area of Hubei and Henan provinces where cases of fever with thrombocytopenia syndrome were prevalent. We classified the ticks by morphology characteristics before 12S rDNA of ticks were amplified by PCR and subsequently sequenced. Phylogenetic tree was constructed by PAUP4.0. Results The ticks belonged to Haemaphysalis longicomis and Rhipicephalus microplus through observation and analysed by the morphological characteristics of the ticks. 12S rDNA was cloned and sequenced while data confirmed the morphological identification of the results. Conclusion The method based on morphology that combined with molecular marker seemed a good method for the identificaton of ticks.

An epidemiological investigation of the rabies between 1999-2008 in Yancheng city,Jiangsu province / 中华流行病学杂志

Objective To better understand the epidemiology of rabies during the past ten years in Yancheng city,Jiangsu province. Methods Data was collected and analyzed on rabies cases in Yancheng. Density and vaccination rate on Canine,Rate of injured people bit by dogs,and the information of post-exposure prophylaxis were studied. Rabies virus in the dog brains,collected around the epidemic areas of Yancheng,were detected and analyzed. Results A total of 135 human rabies cases occurred from 1999 through 2008,and formed the second epidemic peak since 1958. Of these victims,84% (114) were farmers. In general,the rate of people having dogs were 3%-6% per 100 people,and the injured person-times of 100 dogs were 6.37 per year. Notably,the vaccination rate of dogs was only 20%. Of those people injured by dogs and other animals,77% had received post-exposure treatment,and only 5%-10% had been administered anti-rabies serum. Rabies virus antigen was found in 4 (3.6%) of 111 brain specimens among dogs collected from epidemic areas. Genetic analysis of N and G genes,which were amplified from brain specimens,indicated that these viruses belong to genotype Ⅰ rabies and expressing a close relationship with the Chinese vaccine strain CTN. Conclusion The large number of dogs with low vaccination rate among them,together with the incorrect and low post-exposure treatment in rural areas seemed to be responsible for the outbreak of rabies in Yancheng city.