Detection and sequential analysis of Granulocytic ehrlichia 444-Epank gene / 中华流行病学杂志

<p><b>OBJECTIVE</b>To provide further pathogenic evidence of Granulocytic ehrlichia infection in China.</p><p><b>METHODS</b>Specific primers derived from 444-Epank gene were used to amplify Granulocytic ehrlichia DNA from specimens of ticks, animals and human blood. PCR products of ticks were cloned and sequenced.</p><p><b>RESULTS</b>444 bp specific DNA fragments were amplified from 2 of 62 pools of Ixodes persulcatus collected from Heilongjiang province and 1 of 129 blood specimens from forest workers in Inner Mongolia. Eight animal specimens were negative. PCR products from ticks were then cloned and sequenced. It differed at 23 positions in comparison to American strain (AF047897) with 94.9% homology. The homology of deduced ammonia was 88.44%.</p><p><b>CONCLUSION</b>Our findings further confirmed that Granulocytic ehrlichia infection did exist in China.</p>

Exploratory study on natural focus and its causative agent of genotype of Lyme disease by polymerase chain reaction in the forest areas of Beijing / 中华流行病学杂志

<p><b>OBJECTIVE</b>To learn the existence of natural focus of Lyme disease and its distribution.</p><p><b>METHODS</b>A semi-nested polymerase chain reaction (PCR) method was developed for detection and genotyping of Borrelia burgdorferi on basis of outer surface protein A (OspA) gene. Ticks and mice collected from 6 forest areas in Beijing were detected with above methods. The positive PCR products were cloned and sequenced. The sequences were compared with published sequences for homology. IFA as used to detect IgG antibody on Borrelia burgdorferi. Lyme disease spirochete were isolated from H. longicornis were also attempted.</p><p><b>RESULTS</b>B. Burgdorferi sensu lato were detected from 939 ticks and 250 mice specimens collected from above 6 study sites using primer pairs OA(1)/OA(4) and SL/OA(4). Only the specimens collected from Dongling mountain showed positive amplification. One in three adult Ixodes persulcatus with one of 57 nymph Ixodes persulcatus showed positive while 9 of 119 (7.56%) mice specimens showed positive, of which 8 were B. grinii and one B. afzelii. In this study, we attempted to isolate B. burgdorferi sensu lato strains from 160 H. longicornis ticks (20/group) but failed. Serological survey showed a 9.1% (5/55) infection rate with B. burgdorferi sensu lato in the mice of Dongling mountain forest areas.</p><p><b>CONCLUSIONS</b>The natural focus of Lyme disease including B. garinii and B. afzelii might have existed in Dongling mountain of Mentougou district, Beijing. Ixodes persulcatu and mice may serve as vectors and reservoirs, respectively.</p>