Investigation on Anaplasma phagocytophilum infection in rodents from forest areas in northeastern China / 中华流行病学杂志

<p><b>OBJECTIVE</b>To investigate the prevalence of Anaplasma phagocytophilum in rodents from forest areas in northeastern China.</p><p><b>METHODS</b>PCR 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.</p><p><b>RESULTS</b>A 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%.</p><p><b>CONCLUSION</b>A. phagocytophilum infection was presented in rodents from Jilin and Heilongjiang province.</p>

Study on the coinfection status of Borrelia burgdorferi sensu lato and spotted fever group Rickettsia in ticks from Hunchun, Jilin province / 中华流行病学杂志

<p><b>OBJECTIVE</b>To understand the coinfection status of Borrelia burgdorferi sensu lato (B.b.s.l) and spotted fever group Rickettsia (SFGR) in Hunchun of Jilin province, China.</p><p><b>METHODS</b>Polymerase chain reaction (PCR) was used to detect the 5S-23S rRNA intergenic spacer of B. b. s. l and ompA of SFGR in ticks was collected in Hunchun,Jilin province. The amplification products of positive ticks were sequenced, and phylogenetic analysis was conducted by PHYLIP software package.</p><p><b>RESULTS</b>The infection rate of B. b. s. l was 36.0% in Ixodes persulcatus ticks and the SFGR was discovered in I. persulcatus ticks,with an infection rate of 2.0%. The coinfection rate of both agents was 2.0%. In 327 Dermacentor siltarum ticks, the positive rates of B. b. s. l and SFGR were 30.9% and 29.1% respectively. 55 ticks (16.8%) were coinfected with the two pathogens. The sequence analysis of B. b. s. l showed that the B. b. s. l in Jilin area, which were highly homologous, all belonged to B. garinii genotypes. The sequence analysis of SFGR positive products showed that the DNA secquence of the newly detected agent (JL-95) was close to the two previously described rickettsiae which were detected in I. ricinus from Slovakia (called IRS3 and IRS4). Phylogenetic relationships inferred from the comparison of these sequences with those of other genus Rickettsiae indicated that JL-95, IRS3 and IRS4 constituted a new rickettsial genotype and formed a separate cluster among the spotted fever group Rickettsiae.</p><p><b>CONCLUSION</b>Coinfection of B. b. s. l and SFGR existed in Hunchun, Jilin province. The sequencing of specific fragment confirmed a new SFGR which was different from other rickettsiae known in China.</p>

Optimization of a Liquid Chip System for the Detection of Serum Biomarkers of Colorectal Cancer and Its Application / 中国生物工程杂志

Liquid chip technology have been licensed to be used in clinic because of its advantage of high-throughput, high-sensitivity, good signal to noise ratio, reaction in liquid phase, convenient operation and short time consuming, etc. The optimization of a liquid chip system for the detection of serum biomarkers of colorectal tumour and initial application in the detection of CEA were studied. The optimized reaction conditions of liquid chip were determined through orthogonal design after it was prepared. The results showed that the consuming reaction time of the coated antibody and the antigen was 1hour. The microspheres, biotinylated detecion antibody and the consuming complexes and avidin-PE time of the microspheres and the biotinylated tested antibody was 1hour, 1hour and 15minutes respectively.the consuming time of the complexes and avidin-PE was fifteen minutes, The optimized dilution of the biotinylated tested detection antibody was 1∶300 and the optimized concentration of avidin-PE was 12?g/ml. Totally 55 clinical samples were detected by the liquid chip and by Enzyme-Linked Immunosorbent Assay (ELISA) simultaneously and the results of the two methods were compared. The results of the two methods showed good correlation between positive and negative samples but the detection limits and the dynamic ranges of the liquid chip method were more sensitive and wider than those of the ELISA. The multiple tumour biomarkers may be detected simultaneously and the time of clinical test and manpower requirements were reduced by the liquid chip method.