Prevalence of Candidatus Rickettsia tarasevichiae-Like Bacteria in Ixodid Ticks at 13 Sites on the Chinese-Russian Border.

To investigate the likely source population and candidate vectors of Candidatus Rickettsia tarasevichiae, the prevalence of this bacteria was quantified in specimens of four tick species that mainly parasitize humans collected from 13 sites along the Chinese-Russian border. The presence of the bacteria was determined by detecting its specific citrate synthase (gltA) partial gene and outer membrane protein A (ompA) partial gene. Only Ixodes persulcatus Schulze was found to be naturally infected with C. R. tarasevichiae, which had an overall prevalence of 1.53% in both sexes. C. R. tarasevichiae is an emerging, tick-borne human pathogen and this finding may partially explain recent human cases of infection by this organism in China. Public health authorities should be aware of the potential risk posed by the transmission of this bacterium to humans by ticks.

[Development and evaluation of the kit for detection of SARS-associated Coronavirus RNA]. / Razrabotka i aprobtsiia test-sistemy dlia vyiavleniia RNK virusa vizyvaiushchego tiagezhelyi ostryi resperativnyi sindrom.

AIM: To develop a diagnostic kit for detection of SARS (severe acute respiratory syndrome)-related coronavirus RNA based on reverse transcription and polymerase chain reaction and to estimate its specificity and sensitivity. MATERIAL AND METHODS: 68 virus and bacterial cultures, 240 clinical samples from people without SARS symptoms and also 22 RNA samples from patients with SARS symptoms received during the epidemic in Beijing were used. RESULTS: The specificity of the kit was determined using animal coronaviruses and other bacterial and viral strains, causing acute respiratory and intestinal infections, and was shown to be 100%. The sensitivity of the kit in different clinical samples was 2.2 x 10(3) genome equivalents of recombinant SARS RNA in 1 ml of the specimen. The kit was evaluated in the Institute of Microbiology and Epidemiology of Beijing (China) using SARS-cov viral suspension and clinical samples from patients with suspected SARS. It was shown that kit was able to detect 10 TCID/50 ml of SARS-Cov virus. Testing of clinical samples from patients with suspected SARS showed that diagnostic sensitivity of the kit was 95%. Detection of the SARS-Cov RNA was more effective in feces compared to sputum 990 and 40%, respectively). CONCLUSION: The kit "AmpliSens SARS" for qualitative detection of SARS-related coronavirus RNA by reverse transcription and polymerase chain reaction (PCR) in nasopharyngeal wash/aspirates, naso/oropharyngeal swabs, plasma, and extract from feces has been developed in the Central Research Institute for Epidemiology of the RF Ministry of Health. The kit contains reagents for RNA isolation and purification, cDNA synthesis by reverse transcription of RNA, for PCR and for electrophoretic analysis of amplified products. The kit also contains recombinant positive and internal control samples allowing to control efficiency of analysis and showed good analytical and diagnostic characteristics.