ABSTRACT
<p><b>OBJECTIVE</b>To characterize the hepatitis A virus (HAV) wild type strains circulating in Hebei Shijiazhuang of China during 2005-2007, to provide the bases for further investigation of the sources of HAV infection.</p><p><b>METHODS</b>The VP1/P2A junction regions were detected by RT-PCR from HAV IgM positives serum samples during 2005 and 2007, the 34 RT-PCR positive samples were sequenced and subjected to phylogenetic analysis by Neighbor Joining (NJ) method.</p><p><b>RESULTS</b>All the detected HAV strains were identified as sub-genotype I A, the homology of nucleotide sequence in the VP1-2A imation region ranged from 95%-100%, the amino acid sequences of HAV strains almost had no difference.</p><p><b>CONCLUSION</b>There are different HAV strains existing in Hebei Shijiazhuang of China, same HAV strain may exist in different areas; or in one area, identical or different HAV strains may be detected. This work provides the bases for further investigation of the sources of HAV infection and also for effectively control measures to prevent the spread of the disease.</p>
Subject(s)
Adolescent , Child , Female , Humans , Male , Young Adult , Acute Disease , China , Hepatitis A , Virology , Hepatitis A Virus, Human , Classification , Genetics , Molecular Sequence Data , Phylogeny , Viral Structural Proteins , GeneticsABSTRACT
<p><b>OBJECTIVE</b>To develop an extraction and concentration method for the detection of hepatitis A virus (HAV) in shellfish, water, serum and saliva samples by nested RT-PCR.</p><p><b>METHODS</b>HAV were artificially inoculated into the above samples, calm sample was extracted using glycine buffer pH9.5, PEG precipitation; water sample was PEG precipitated directly; then all the samples including serum and saliva samples were extracted using Trizol regent, followed by nested RT-PCR detection using primers from HAV VP1-2A region.</p><p><b>RESULTS</b>The detection limit for HAV in cultured cell lysis was 0.1TCID50; in water, serum or salva sample was 1TCID50 respectively, in calm sample was 1-10 TCID50. HAV RNA was detected in water and sera samples collected from the HAV outbreak region, sequenced and analysis.</p><p><b>CONCLUSION</b>The method developed here is convenient, specific and capable of detecting low levels of HAV in different samples, would be useful for diagnostic laboratories in order to perform HAV analysis in cases of foodborne infections or for molecular epidemiology investigation of HAV outbreaks.</p>
Subject(s)
Animals , Humans , Chemical Fractionation , Methods , Fresh Water , Virology , Genetic Techniques , Hepatitis A , Diagnosis , Virology , Hepatitis A virus , Genetics , RNA, Viral , Chemistry , Genetics , Saliva , Virology , Serum , Virology , Shellfish , VirologyABSTRACT
<p><b>OBJECTIVE</b>To study the influence of Candida albicans on human immunodeficiency virus (HIV)-positive individuals susceptible to oral candidiasis.</p><p><b>METHODS</b>In vitro secreted aspartyl proteinase activities, adhesion to healthy buccal epithelial cells of Candida albicans isolates from oral cavities of subjects with and without HIV infection were measured.</p><p><b>RESULTS</b>The pathogenetic isolates of Candida albicans from HIV-positive patients were significantly lower than that from HIV-negative subjects (P < 0.01) in secreted aspartyl proteinase activities and adhesion to buccal epithelial cells. There was no difference in commensals between these two groups. In the HIV-positive group, no difference was found between the pathogenetics and the commensals. However, in the HIV-negative group, the virulence of the pathogen was significantly higher than the commensals (P < 0.01).</p><p><b>CONCLUSIONS</b>These results indicate that oral candidiasis was not correlated with some predominant strains of Candida albicans with higher virulence in HIV-positive subjects.</p>