ABSTRACT
OBJECTIVE: To clarify the gene type of Orientia tsutsugamushi (Ot) from Shandong province. METHODS: Nested-polymerase chain reaction (nPCR) was used to identify the gene type of 23 isolated Ot strains, 2 pools of homogenized leptotrombidium (L.) scutellare, 10 blood specimens of scrub typhus patients, and at the same time to compare with the international reference strains Gilliam, Karp, Kato. Sequencing analysis of the Sta56 gene was also used to further identify the precise gene types. RESULTS: Of the 35 samples, 33 had the same products in the amplification of template Ot-DNA. They all belonged to Kawasaki strains endemic in Japan while 2 (FXS4 and LHGM2 strain) belonged to Karp strains. The Sta56 gene sequence homologies to Japan Kawasaki strain of the 2 representative strains (B-16 and FXS2 strain) of the 33 samples were 94.22%, 95.21% respectively, but they were less than 75.87% to other prototype strains; The homologies to Karp strain of FXS4 and LHGM2 strain were 83.03%, 96.45% respectively. B-16 and FXS2 strain were designated as of types strain Japan Kawasaki, FXS4 and LHGM2 as Karp strain. CONCLUSION: The results indicated that the dominant Ot strains in Shandong Province were similar to Kawasaki strains, but Karp strains also existed.
Subject(s)
DNA, Bacterial/genetics , Orientia tsutsugamushi/genetics , Polymorphism, Restriction Fragment Length , Scrub Typhus/microbiology , Animals , Genotype , Humans , Mice , Polymerase Chain Reaction , Scrub Typhus/epidemiology , Sequence Homology , SerotypingABSTRACT
OBJECTIVE: To investigate the epidemiological significance of hemorrhagic fever with renal syndrome virus (HFRSV) infection in domestic pigs in Shandong province, and study the role of domestic pigs in the prevalence of HFRS. METHODS: Epidemiological investigation was performed in 4 cities of Shandong province. Reversed passive hemagglutination assay (RPHA), reversed passive hemagglutination inhibition (RPHI), HPR-SPA, immunofluorescent antibody (IFA), and reverse transcriptional PCR (RT-PCR) were used to detect antigen and antibody of HFRSV. RESULTS: HFRSV antigen and antibody were detected in the heart, liver, lung, spleen, kidney, blood, urine, and stool of domestic pigs as well as in the sewage of the pigpen facilities. The positivity rate of HFRSV antigen ranged from 3.33% to 5.00% in the organ of pigs, and HFRSV positivity rate in the blood, urine, stool, and sewage was 3.67%, 7.04%, 2.51%, and 5.56%, respectively, with a total serum antibody positivity rate of 1.96%. The virus was isolated from the HFRSV antigen-positive samples, and could infect many organs after artificial infection of the pigs. HFRSV antigen can be detected in suckling rat brain and histopathological examination suggested transient pathological changes in such organs as the liver, lung and kidney. HFRSV may proliferate in pigs and was discharged through multiple routes. CONCLUSION: Domestic pigs can be the host of HFRSV for the viral transmission.
