ABSTRACT
<p><b>OBJECTIVE</b>In this study, milk from a cow with mastitis was analyzed to determine the presence of mycobacterial infection. Milk quality and security problems pertaining to the safe consumption of dairy products were also discussed in this study.</p><p><b>METHODS</b>Milk was preprocessed with 4% NaOH. Then, mycobacteria were isolated from the milk sample on L-J medium. The isolate was identified using multiple loci Polymerase Chain Reaction (PCR) and multi-locus sequence analysis with 16S rRNA, sodA, hsp65, and ITS genes. The drug sensitivity of the isolate to 27 antibiotics was tested through alamar blue assay.</p><p><b>RESULTS</b>Smooth, moist, pale yellow colonies appeared on the L-J medium within a week after inoculation. Based on the results of multiple loci PCR analysis, the isolate was preliminarily identified as non-tuberculous mycobacteria. The 16S rRNA, SodA, hsp65, and ITS gene sequences of the isolate exhibited 99%, 99%, 99%, and 100% similarities, respectively, with those of the published reference strains of Mycobacterium elephantis (M. elephantis). The drug sensitivity results showed that the strain is resistant to isoniazid, p-aminosalicylic acid, and trimesulf but is sensitive to ofloxacin, rifampicin, amikacin, capreomycin, moxifloxacin, kanamycin, levofloxacin, cycloserine, ethambutol, streptomycin, tobramycin, rifabutin, ciprofloxacin, linezolid, cefoxitin, clarithromycin, and minocycline.</p><p><b>CONCLUSION</b>To the best of our knowledge, this study is initially to report the isolation of M. elephantis from the milk of a cow with mastitis in China.</p>
Subject(s)
Animals , Cattle , Female , Anti-Bacterial Agents , Pharmacology , China , Drug Resistance, Bacterial , Mastitis, Bovine , Epidemiology , Microbiology , Milk , Microbiology , Mycobacterium , Genetics , Mycobacterium Infections , Epidemiology , Microbiology , Phylogeny , Polymerase Chain ReactionABSTRACT
A set of universal loop-mediated isothermal amplification (LAMP) primers targeting the fla gene was designed to detect Borrelia burgdorferi sensu lato (B. burgdorferi s.l.) in human samples. The sensitivity of LAMP was 20 copies/reaction, and the assay did not detect false positives among 11 other related bacteria. A positive LAMP result was obtained for 9 of the 24 confirmed cases and for 12 of 94 suspected cases. The positive rate of LAMP was the same as that of nested PCR. The LAMP is a useful diagnostic method that can be developed for rapid detection of B. burgdorferi s.l. in human sera. Combination of the LAMP and nested PCR was more sensitive for detecting B. burgdorferi s.l. in human serum samples.
Subject(s)
Humans , Borrelia burgdorferi Group , Genetics , China , DNA, Bacterial , Genetics , Lyme Disease , Diagnosis , Nucleic Acid Amplification Techniques , Methods , Polymerase Chain Reaction , Methods , Sensitivity and SpecificityABSTRACT
<p><b>OBJECTIVE</b>To analyze the infection of human parvovirus B19, human bocavirus (HBoV) and human parvovirus 4 (PARV4) in blood samples among patients with liver disease in Nanjing by molecular detection.</p><p><b>METHODS</b>Nested PCR assays were designed and validated to detect B19, HBoV and PARV4, respectively. The assays were used to screen three parvoviruses in blood samples from 95 patients with different liver disease in Nanjing. The parvovirus infection was analyzed statistically.</p><p><b>RESULTS</b>The detection limits were 10 copies of genomic DNA equivalents per reaction for each assays and the good specificity were observed. The frequency of B19 and HBoV were 2/95 (2.1%) and 9/95 (9.5%) in blood samples respectively. No PARV4 was detected. HBoV was detected in 3/5 patients with drug-induced hepatitis.</p><p><b>CONCLUSION</b>Both B19 and HBoV infection were detected in blood from patients with liver disease.</p>
Subject(s)
Adolescent , Adult , Aged , Child , Female , Humans , Male , Middle Aged , Coinfection , Virology , Human bocavirus , Liver Diseases , Virology , Parvovirus , Parvovirus B19, Human , Polymerase Chain Reaction , Viremia , VirologyABSTRACT
<p><b>OBJECTIVE</b>To establish a TaqMan real-time fluorescent quantitative PCR to detect Vibrio vulnificus based on the hemolysin gene (vvhA) coding cytolysin.</p><p><b>METHODS</b>Primers and probes in the conserved region of the vvhA gene sequence were designed for the TaqMan real-time PCR to detect 100 bp amplicon from V. vulnificus DNA. Recombinant plasmid pMD19-vvhA100 was constructed and used as a positive control during the detection. Minimal amplification cycles (Ct value) and fluorescence intensity enhancement (DeltaRn value) were used as observing indexes to optimize the reaction conditions of TaqMan real-time PCR. The TaqMan assay for the detection of Vbirio vulnificus was evaluated in pure culture, mice tissue which artificially contaminated Vibrio vulnificus and clinical samples.</p><p><b>RESULTS</b>The established TaqMan real-time PCR showed positive results only for Vibrio vulnificus DNA and pMD19-vvhA100. The standard curve was plotted and the minimum level of the vvhA target from the recombinant plasmid DNA was 10(3) copies with a Ct value of 37.94+/-0.19, as the equivalent of 0.01 ng purified genomic DNA of Vibrio vulnificus. The results detected by TaqMan PCR were positive for the 16 clinical samples and all the specimens of peripheral blood and subcutaneous tissue of mice which were infected with Vibrio vulnificus.</p><p><b>CONCLUSION</b>TaqMan real-time PCR is a rapid, effective, and quantitative tool to detect Vibro vulnificus, and can be used in clinical laboratory diagnosis of septicemia and wound infection caused by Vibrio vulnificus.</p>
Subject(s)
Animals , Mice , Bacterial Proteins , Genetics , Base Sequence , DNA Primers , Mice, Inbred ICR , Polymerase Chain Reaction , Methods , Reproducibility of Results , Sensitivity and Specificity , Vibrio vulnificusABSTRACT
Objective To establish a TaqMan real-time fluorescent quantitative PCR to detect Vibrio vulnificus based on hemolysin gene(vvhA)that coding cytolysin.Method By using software Primer Express, the PCR primers and TaqMan probe,which located in the conserved region of vvhA gene sequence,were designed for establishment of a TaqMan real-time fluorescent quantitative PCR to detect 100 bp amplicon from V.vulnificus DNA.A recombinant plasmid pMD19-vvhA100 as a positive control during detection was constructed using gene cloning technique.Minimal amplification cycles(Ct value)and fluorescence intensity enhancement (△Rn value)were used as observing index to optimize the reaction conditions of the TaqMan real-time fluorescent quantitative PCR.The DNAs with different concentrations from V.vulnificus and other eight bacteria and pMD19- vvhA100 were applied as templates to determine the specificity,sensitivity and reappearance of the TaqMan real- time fluorescent quantitative PCR.ICR mice were intraperitoneally,subcutaneously and orally infected with V. vulnificus,respectively.The detection effect of the TaqMan real-time fluorescent quantitative PCR was measured using the specimens of peripheral blood,subcutaneous tissue and intestinal content collected from the infected mice.Results The established TaqMan real-time fluorescent quantitative PCR showed positive results only for V. vulnificus DNA and pMD19-vvhA100.The detection effectiveness of the TaqMan real-time fluorescent quantitative PCR was as high as 0.01 ng of V.vulnificus DNA or 103 copies of pMD19-vvhA100.The SD values of the detection results repeated for three times using pMD19-vvhA100 with different concentrations were lease than 0.79. The detection results of TaqMan real-time fluorescent quantitative PCR were positive for all the specimens of peripheral blood and subcutaneous tissue.Conclusions The TaqMan real-time fluorescent quantitative PCR established in this study for V.vulnificus vvhA gene detection has advantages such as quickness,stability, sensitivity and specificity,indicating this method can be used for clinical laboratory diagnosis of septicemia and wound infection caused by V.vulnificus.