Loop-mediated isothermal amplification for detecting enterohemorrhagic Escherichia coli O157:H7: a comparison with PCR / 南方医科大学学报

<p><b>OBJECTIVE</b>To establish a rapid method of loop-mediated isothermal amplification (LAMP) for detecting enterohemorrhagic Escherichia coli (EHEC) O157:H7.</p><p><b>METHODS</b>Six primers that specifically recognized the rfbE gene of EHEC O157:H7 were designed. Under the optimized reaction conditions, LAMP and PCR were evaluated for the sensitivity and specificity in the detection of 39 laboratory samples of EHEC O157:H7 strains, and their detection results of contaminated fresh pork samples were compared.</p><p><b>RESULTS</b>LAMP assay correctly identified all the 7 EHEC O157:H7 strains and showed negative results for all the 32 non-EHEC O157:H7 strains. The detection limit of LAMP was much lower than that of rfbE-PCR (10 vs 100 cfu/ml). In the detection of the contaminated pork samples, both LAMP and PCR yielded results consistent with those by the conventional detection method.</p><p><b>CONCLUSION</b>The rfbE-based LAMP assay can serve as a rapid, sensitive, specific and low-cost means for detecting EHEC O157:H7 strain.</p>

Distribution and Drug Resistance of Pathogens in Respiratory Tract in Children / 中华医院感染学杂志

OBJECTIVE To investigate pathogenic bacteria isolated from children with respiratory tract infection(RTI) and bacterial resistance to commonly used antimicrobial agents in Guilin area,so as to instruct the rational use of antibiotics.METHODS Routine methods were used to isolate and identify bacteria species and samples of sputum or throat swabs were collected from children with respiratory infection in inpatient departments.The drug susceptibility tests were performed by Kirby-Bauer method.RESULTS Total 733 strains of bacteria were isolated.The Haemophilus influenzae(HI) was the most common(165 strains),followed by Escherichia coli(136 strains) and Streptococcus pyogenes(51 strains).The resistance of HI to trimetoprim-sulfa methoxazole and ampicillin was 59.39% and 36.36%,respectively.Cephalosporins and quinolones were more sensitive to HI.Imipenem,quinolones and amikacin were more sensitive to E.coli as yet.The resistant rate of Streptococcus to penicillin-G,erythromycin,clindamycin and trimetoprim-sulfa methoxazole was 56.79-69.63%.CONCLUSIONS Gram-negative bacilli are the main pathogenic bacteria in childrens respiratory tract infection.The drug resistance is conspicuous.Antibiotics for treating RTI should be selected based on pathogenic bacteria variance and the drug susceptibility test.