Objective:To explore the hypothesis of "pathogen storage pool" by analyzing the local microbial community of adenoids. Methods:Under the guidance of a 70° nasal endoscope, sterile swabs were used to collect secretions from the adenoid crypts of the subjects. The samples were sent to the laboratory for DNA extraction and standard bacterial 16S full-length sequencing analysis. Results:At the species level, the top three microbial communities in adenoid crypts were Bacillus subtilis（18.78%）, Fusobacterium pyogenes（11.42%）, and Streptococcus pneumoniae（9.38%）. Conclusion:The local microbial community of adenoids exhibits a high degree of diversity, including microbial communities from the oral cavity and gastrointestinal tract. Our research results support the hypothesis that adenoids act as a " pathogen reservoir".
Humans ; Adenoids/microbiology* ; RNA, Ribosomal, 16S/genetics* ; Microbiota/genetics* ; Streptococcus pneumoniae/isolation & purification* ; Bacillus subtilis/genetics* ; DNA, Bacterial/analysis*

OBJECTIVES: To detect prfA and hly toxin genes of Listeria monocytogenes using polymerase chain reaction (PCR) and colloidal gold technology. METHODS: L. monocytogenes DNA was extracted by boiling method. With prfA and hly of L. monocytogenes as the target genes, the 5' ends of upstream and downstream primers of prfA gene were labeled with 6-FAM and biotin, and the 5' ends of upstream and downstream primers of hly gene were labeled with digoxin and biotin, respectively, to establish the toxin gene detection method. Using cloning transformation, sequencing analysis, cloning of positive control products, the detection kid was developed and its specificity, sensitivity, reproducibility and stability were tested, followed by verification with sample testing. RESULTS: The concentration of L. monocytogenes DNA extracted by boiling method was 148.81±0.97 ng/μL, and the A₂₆₀/A₂₈₀ ratio ranged from 1.8 to 2.0. The PCR products showed a 100% homology with the gene sequences in GenBank database after cloning, transformation and sequencing. The colloidal gold strip yielded positive results only for L. monocytogenes samples without cross-reactions with Staphylococcus aureus, Escherichia coli or Bacillus cereus, and its minimum detection limit was 10^-2 ng/μL, demonstrating a 10-fold greater sensitivity of the test than agarose gel electrophoresis. The test also showed good reproducibility of the results when performed by different operators with good stability of the test strips after storage for 6 to 12 months. The test results showed that this kit could accurately and quickly detect L.monocytogenes in the test samples. CONCLUSIONS The detection kit developed in this study can simultaneously detect prfA and hly toxin genes of L. monocytogenes with good specificity, sensitivity, reproducibility and stability for use in food safety inspection.
Listeria monocytogenes/isolation & purification* ; Gold Colloid ; Bacterial Toxins/genetics* ; Polymerase Chain Reaction/methods* ; Hemolysin Proteins/genetics* ; Bacterial Proteins/genetics* ; DNA, Bacterial/genetics* ; Food Microbiology ; Heat-Shock Proteins

Objective: To evaluate multidrug resistant loop-mediated isothermal amplification (MDR-LAMP) assay for the early diagnosis of multidrug-resistant tuberculosis and to compare the mutation patterns associated with the Methods: MDR-LAMP assay was evaluated using 100 Results: The sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of MDR-LAMP were 85.5%, 93.6%, 96.7%, and 74.4% for the detection of resistance to isoniazid and rifampicin, respectively, and 80.5%, 92.3%, 98.6%, and 41.4% for the detection of Conclusion MDR-LAMP is a rapid and accessible assay for the laboratory identification of rifampicin and isoniazid resistance of
Antitubercular Agents ; Bacterial Proteins/genetics* ; Catalase/genetics* ; DNA, Bacterial/analysis* ; DNA-Directed RNA Polymerases/genetics* ; Drug Resistance, Multiple, Bacterial/genetics* ; Isoniazid ; Molecular Diagnostic Techniques/methods* ; Mutation ; Mycobacterium tuberculosis/isolation & purification* ; Nucleic Acid Amplification Techniques/methods* ; Oxidoreductases/genetics* ; Phenotype ; Rifampin ; Whole Genome Sequencing

Cholera is a secretory diarrhoeal disease caused by infection with Vibrio cholerae, primarily the V. cholerae O1 El Tor biotype. There are approximately 2.9 million cases in 69 endemic countries annually, resulting in 95 000 deaths. Cholera is associated with poor infrastructure and lack of access to sanitation and clean drinking water. The current cholera epidemic in Yemen, linked to spread of V. cholerae O1 (Ogawa serotype), is associated with the ongoing war. This has devastated infrastructure and health services. The World Health Organization had estimated that 172 286 suspected cases arose between 27th April and 19th June 2017, including 1170 deaths. While there are three oral cholera vaccines prequalified by the World Health Organization, there are issues surrounding vaccination campaigns in conflict situations, exacerbated by external factors such as a global vaccine shortage. Major movements of people complicates surveillance and administration of double doses of vaccines. Cholera therapy mainly depends on rehydration, with use of antibiotics in more severe infections. Concerns have arisen about the rise of antibiotic resistance in cholera, due to mobile genetic elements. In this review, we give an overview of cholera epidemiology, virulence, antibiotic resistance, therapy and vaccines, in the light of the ongoing epidemic in Yemen.
Anti-Bacterial Agents ; therapeutic use ; Cholera ; drug therapy ; prevention & control ; Cholera Vaccines ; therapeutic use ; DNA, Bacterial ; genetics ; Disease Outbreaks ; Drug Resistance, Multiple, Bacterial ; Humans ; Microbial Sensitivity Tests ; Polymerase Chain Reaction ; Vibrio cholerae ; drug effects ; isolation & purification ; Virulence Factors ; genetics ; Yemen

Objective: To analyze the effect of the identification and evaluation of Escherichia (E.) coli and Shigella, based on the upstream flanking sequences of CRISPR1. Methods: Both CRISPR and cas sequences were obtained through the BLAST with repeating sequences against the publicly complete genome in GenBank that related to E. coli and Shigella. Clustal X was used to perform multi-sequences alignment of the flanking sequences. PCR method was used to amplify the upstream flanking sequences of CRISPR1 in order to appraise the effect of identification and evaluation of upstream flanking sequences on E. coli and Shigella, which were based on the upstream flanking sequences of CRISPR1. Results: The results showed that 73.4% of the strains containing the I-E CRISPR/Cas that belonged to the phylogroups A, B1, D while 8.4% strains carried the I-F CRISPR/Cas. Another 17.2% of the strains owned CRISPR3-4 (non-CRISPR/Cas) only belonged to the phylogroups B2. All the Shigella strains carried I-E CRISPR/Cas. More than 99% of similarity the CRISPR1 upstream-flanking sequences was seen in E. coli (except B2) and Shigella and E. coli (B2). Both sensitivity and specificity were greater than 91% after PCR amplification in the region to identify the E.coli and Shigella. Conclusion: The upstream of CRISPR1 could achieve a preliminary identification effect on E.coli and Shigella.
Clustered Regularly Interspaced Short Palindromic Repeats/genetics* ; DNA, Bacterial/genetics* ; Escherichia coli/isolation & purification* ; Genotype ; Humans ; Molecular Sequence Data ; Sequence Analysis, DNA ; Shigella/isolation & purification*

OBJECTIVELower respiratory tract infections continue to pose a significant threat to human health. It is important to accurately and rapidly detect respiratory bacteria. To compensate for the limits of current respiratory bacteria detection methods, we developed a combination of multiplex polymerase chain reaction (PCR) and capillary electrophoresis (MPCE) assay to detect thirteen bacterial pathogens responsible for lower respiratory tract infections, including Streptococcus pneumoniae, Haemophilus influenzae, Moraxella catarrhalis, Pseudomonas aeruginosa, Klebsiella pneumoniae, Escherichia coli, Staphylococcus aureus, Mycoplasma pneumoniae, Legionella spp., Bordetella pertussis, Mycobacterium tuberculosis complex, Corynebacterium diphtheriae, and Streptococcus pyogenes.

METHODSThree multiplex PCR reactions were built, and the products were analyzed by capillary electrophoresis using the high-throughput DNA analyzer. The specificity of the MPCE assay was examined and the detection limit was evaluated using DNA samples from each bacterial strain and the simulative samples of each strain. This assay was further evaluated using 152 clinical specimens and compared with real-time PCR reactions. For this assay, three nested-multiplex-PCRs were used to detect these clinical specimens.

RESULTSThe detection limits of the MPCE assay for the 13 pathogens were very low and ranged from 10-7 to 10-2 ng/μL. Furthermore, analysis of the 152 clinical specimens yielded a specificity ranging from 96.5%-100.0%, and a sensitivity of 100.0% for the 13 pathogens.

CONCLUSIONThis study revealed that the MPCE assay is a rapid, reliable, and high-throughput method with high specificity and sensitivity. This assay has great potential in the molecular epidemiological survey of respiratory pathogens.

Bacteria ; classification ; genetics ; isolation & purification ; Bacteriological Techniques ; DNA, Bacterial ; genetics ; Electrophoresis, Capillary ; methods ; Humans ; Multiplex Polymerase Chain Reaction ; methods ; Respiratory Tract Infections ; microbiology ; Sensitivity and Specificity

No abstract available.
Anti-Bacterial Agents/*pharmacology ; Azabicyclo Compounds/*pharmacology ; Bacterial Proteins/genetics ; Ceftazidime/*pharmacology ; Cephalosporins/*pharmacology ; DNA, Bacterial/genetics/metabolism ; Drug Resistance, Bacterial/*drug effects ; Gram-Negative Bacteria/drug effects/*isolation & purification ; Humans ; Microbial Sensitivity Tests ; Penicillanic Acid/*analogs & derivatives/pharmacology ; Pseudomonas aeruginosa/drug effects/isolation & purification ; Real-Time Polymerase Chain Reaction

No abstract available.
Aged ; Anti-Bacterial Agents/pharmacology/therapeutic use ; Cefotaxime/analogs & derivatives/therapeutic use ; Cholangiopancreatography, Endoscopic Retrograde ; Gallstones/surgery ; Gram-Negative Anaerobic Bacteria/drug effects/genetics/*isolation & purification ; Gram-Negative Bacterial Infections/*diagnosis/drug therapy/microbiology ; Humans ; Male ; Metronidazole/therapeutic use ; Microbial Sensitivity Tests ; RNA, Ribosomal, 16S/chemistry/genetics/metabolism ; Sequence Analysis, DNA ; Tomography, X-Ray Computed

In order to develop a rapid and reliable method for B. cereus genotyping, factors influencing PFGE results, including preparation of bacterial cells embedded in agarose, lysis of embedded cells, enzymatic digestion of intact genomic DNA, and electrophoresis parameters allowing for reproducible and meaningful DNA fragment separation, were controlled. Optimal cellular growth (Luria-Bertani agar plates for 12-18 h) and lysis conditions (4 h incubation with 500 µg/mL lysozyme) produced sharp bands on the gel. Restriction enzyme NotI was chosen as the most suitable. Twenty-two isolates were analyzed by NotI digestion, using three electrophoretic parameters (EPs). The EP-a was optimal for distinguishing between isolates. The optimized protocol could be completed within 40 h which is a significant improvement over the previous methods.
Bacillus cereus ; genetics ; isolation & purification ; Bacteriological Techniques ; DNA, Bacterial ; chemistry ; genetics ; Electrophoresis, Gel, Pulsed-Field ; methods

We evaluate the performance of Xpert MTB/RIF for the diagnosis of extrapulmonary tuberculosis (EPTB) in China. The performance of Xpert was evaluated compared to the composite reference standard (CRS), drug susceptibility testing (DST), and imaging examination. The overall sensitivity and specificity of Xpert were 64.1% (195/304) and 100% (24/24), respectively, using CRS as the gold standard. The sensitivity was significantly higher than that of culture for pus (P<0.05). The proportion of EPTB-positive cases diagnosed by imaging was two times more than that diagnosed using Xpert; however, 6 out of 19 cases may have been overdiagnosed by imaging. Compared to phenotypic DST, the sensitivity and specificity of Xpert were 80% (12/15) and 100% (75/75), respectively. Considering its high sensitivity and specificity, Xpert MTB/RIF may be used as a rapid initial test for EPTB diagnosis, and may also support a quicker decision on the treatment regimen. The combination of imaging and Xpert testing could provide high efficiency and accurate diagnosis of suspected EPTB.
Bacterial Proteins ; genetics ; metabolism ; China ; DNA-Directed RNA Polymerases ; genetics ; metabolism ; Diagnostic Tests, Routine ; instrumentation ; methods ; Drug Resistance, Bacterial ; Humans ; Microbial Sensitivity Tests ; Mycobacterium tuberculosis ; drug effects ; genetics ; isolation & purification ; metabolism ; Retrospective Studies ; Rifampin ; pharmacology ; Sensitivity and Specificity ; Sputum ; Tuberculosis ; Tuberculosis, Pulmonary ; diagnosis ; microbiology