Objective:To identify members of genera of rickettsia and O.tsutsugammhi simultaneously.Methods:Rapid and duplex and nested PCR methods have been established by designing primers based on the conserved regions of heat shock protein GroEL gene.345 mouse viscera samples including liver,spleen and kidney,96 Xenopsylla cheopis and 32 chiggers collected from Hongta areas of Yuxi city,Yunnan province were tested by the new PCR methods.Results:The result of the study showed that the new PCR methods could identify most members of genera -Rickettsia and Orientia simultaneously with 100%specificity and its sensitivity could test one copy per microliter.The results of detection prevalence of rickettsioses in mouse,flea and mites DNA samples showed that the total rickettsia infection rate in mouse was 34.78%(120/345).The total infection rates in R.typhi,O.t Karp and R.sibirica of mouse samples were 28.12%(97/345),19.71%(68/345) and O. 29%(1/345) respectively.Co-infection rates in R.typhi and 0.t Karp of mouse samples were 13.33%(46/ 345).O.t Karp type has been the main epidemic strain in these areas.Conclusion:We concluded that this PCR method could be used to detect multi-genera rickettsia simultaneously.Molecular evidences provided in this and previous studies strongly support that Hongta areas of Yuxi city are a natural focus for typhus and scrub typhus with the common occurrence of their confection.
Objective:To investigate the situation of anaplasmosis in Yiyuan county.Shandong Province. Methods:A total of 26 blood samples from febrile patients suspected of anaplasmosis,48 blood samples from healthy farmers,8 from dogs,and 10 from goats and 170 ticks were collected in the same area during 2005-2007,and detected by serological and molecular methods.Results: Eight confirmed cases and 6 probable cases were determined using serologic and molecular methods.The seroprevalence of Anaplasma phagocytophilum(A.phagocytophilum) was 26.7% in healthy cases.Nine out of 10 sheep samples and 7 out of 8 dog samples reacted positively to the A.phagocytophilum antigen.PCR amplification and sequencing of the 16SrRNA of,4. phagocytophilum gene showed that some samples from patients,goats and ticks were 100% identical.The seroprevalence of Rickettsia typhi was 22.9%,Orientia tsutsugamushi 6.3%, Rickettsia sibirica 27.1%,Coxiella burnetii 18.8%,Bartonella henselae 31.3%,and Borrelia burgdorferi 41.6%.Conclusions:It is important to make differential diagnosis of febrile patients and to apply treatment with specific antibiotics.It is needed to enforce essential prevention and control measures including tick control and to improve sanitation conditions.
Lijuan ZhangFeng CuiLingling WangLingling ZhangJingshan ZhangShiwen WangShuxia Yang
We isolated a novel strain of Alphaproteobacteria from a patient,who had medical history of chronic rhinitis for more than twenty years and recently experienced local skin abscess and ulcer. He eventually died of multiple organ failure due to multi-antibiotics resistance.We identified the microorganism by 16SrRNA sequencing and found that it belonged to the genus Rhodoplanes. It was named as Rhodoplanes sp.strain ZLJ-0.It is resumed that Rhodoplanes sp.strain ZLJ-0 might be an emerging human pathogen involving in unknown febrile conditions and could cause local infection of any tissues or organs.Differential diagnosis of febrile patients should be conducted in clinical practice and research on emerging pathogens of Alphaproteobacteria should be performed to determine the epidemiology,clinical symptoms and pathogenic features of these pathogens.
Objective:To report a training course on the laboratory diagnoses of rickettsioses that 10 provincial/city CDCs participated in laboratory external quality assurance(EQA) based on the serological specific antibodies detection and rapid PCR amplifying targeted genes of rickettsiae. Methods:An EQA program to evaluate the following laboratory procedures was developed to detect rickettsiae:(1) immunofluorescent assay(IFA) to detect specific antibodies of A. phagocytophilum,R.heilongjiangensis and 0.tsutsugamshi respectively.(2) Two sets of nested PCR were used amplifying groEL genes for most members of the family Rickettsiaceae and amplifying 16SrRNA genes for the most members of family anaplasmae,respectively.A scoring scheme based on the distribution of the median antibody titer values of the serologic assays was designed and a ranking list of the scores of the PCR results based on the detected minimal copy numbers of reference DNA was created.Results:Among nine laboratories who reported the results on time,eight laboratories gave acceptable serologic results,the other one provided an unacceptable antibody titer(1:2 vs median 1:64) results for 0.tsutsugamshi.The limits of detection(LOD) for the PCR amplifying for five references DNA ranged from 1copy/μL to 10~6 copy/μL.Conclusions:We successfully trained and popularized modern diagnostic methods of rickettsiae in 10 provincial CDCs in China and first conducted the EQA projects and evaluated the results.
