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Objective To determine the spectrum of conjunctival flora and the antibiotic susceptibility profiles of patients scheduled for penetrating intraocular surgeries.Methods A prospective case control study was performed.A total of 192 patients (192 eyes) scheduled for penetrating intraocular surgeries at the Fourth People's Hospital of Shenyang from February to August 2015 were enrolled.Samples from the conjunctival sac were collected before instillation of any ophthalmic solutions for both aerobic and anaerobic culture.The positive rate and bacterial spectrum were observed.Bacterial isolates were tested for antibiotic susceptibility to 7 commonly used ophthalmic antibiotics using automated drug resistance analyzing system.The research was approved by the Ethics Committee of the Fourth People's Hospital of Shenyang.Results Totally 91 strains were collected from 81 conjunctival samples during aerobic culture,the positive rate was 42.19％.Staphylococcus epidermidis was the most common microorganism (64.84％),followed by Staphylococcus lentus (7.69％) and Staphylococcus aureus (3.30％).Coagulatase negtive Staphylococcus (CNS) accounted for 80.22％ of the positively cultured aerobes.For anaerobic culture,a total of 28 strains were isolated from 28 conjunctival samples,the positive rate was 14.58％ Propionibacterium acnes was the predominant species (71.43％),followed by Finegoldia magna (10.71％).Majority of the CNS were sensitive to gentamycin and vancomycin,with resistance rates lower than 10％,but their resistance rate to erythromycin and ceftazidime was 87.67％ and 63.01％,respectively.Resistance rate of these CNS to levofloxacin,ciprofloxacin,and moxifloxacin was 42.47％,39.73％ and 17.81％,respectively.Multidrug resistance to at least 3 antibiotic classes was present in 38.36％ of the CNS.Conclusions Bacteria in the conjunctiva sac of preoperative patients are resistant to various ophthalmic antibiotics.To follow-up the bacterial distribution and antibiotic resistance is great meaningful in the prophylactic and treatment in ocular surgery-related infections.
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Objective To establish a rapid ,sensitive direct method for detecting Escherichia coli (E .coli) in the positive blood culture bottles by using the loop‐mediated isothermal amplification (LAMP) .Methods Based on the lacZ (accession number :M74750) gene sequence of E .coli in the gene sequence GenBank by the National Institutes of Health (NIH) ,4 specific primers (2 inner primers and outer primers) were designed ,the lacZ gene was amplified and the amplification reaction was optimized .The sen‐sitivity and specificity of this method were verified and its comparison with the traditional culture method was conducted .Results Sixty‐eight strains of E .coli were detected in 300 positive blood culture bottles by adopting the LAMP method .The designed prim‐ers had good sensitivity and good specificity for the amplification of E .coli .The sensitivity and specificity of LAMP all reached 100% compared with the traditional method ,but the traditional method needed 3 d to get the results ,while LAMP only needed 1 h . Conclusion LAMP is extremely rapid for detecting E .coli with low cost ,strong specificity and high sensitivity and is suitable for clinical application .
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Objective To apply a one-step loop-mediated isothermal amplification(LAMP) assay for rapid detection of Escherichiaco-li .Methods According to the Genbank of Escherichiacoli lacZ(accession number:M74750) ,a set of four specific primers were designed for the Escherichiacoli LAMP assay and optimized the reaction .The results were judged with naked eyes and electrophoretic analysis .Results Genomic DNAs from 13 bacterial strains including Escherichia coli strains were amplified using LAMP ,and no amplicon was observed in the other bacterial strains .The detection limits of LAMP assay was 15 cfu/mL .Conclusion LAMP assay is extremely rapid ,cost-effective , specific and highly sensitive and has potential usefulness for clinical application .
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Objective To investigate mutation and deletion of genes mecR1 and mecI in clinical methicillin-resistant staphylococci isolates and study the mutation and deletion have effect on gene mecA expression and drug resistance phenotype.Metheods PCR was used to detecte gene mecA and the regulatory genes mecR1 and mecI in staphylococci which were separated from clinical specimen in 2006,then the sequence of gene mecI was determined and compared with the sequence obtains from pre-MRSA strain N315(GI:BA000018).Results Gene mecA was detected in 60 strains of Staphylococcus aureus,58 strains of Staphylococcus epidermidis and 37 strains of Staphylococcus heamolyticus,but gene mecA in 6 strains of Staphylococcus epidermidis and 4 strains of Staphylococcus heamolyticus were only amplified by primer mecA2-F/R and not by primer mecA1-F/R.The percentage of gene mecR1 exist in Staphylococcus aureus was higher than Staphylococcus epidermidis and Staphylococcus heamolyticus,but the percentage of gene mecR1 exist in Staphylococcus epidermidis was not higher than Staphylococcus heamolyticus.The mutation and deletion of gene mecI were often seen,the wild type mecI was only detected in 14 strains,the point mutation of nucleotice 202 was detected in 36 strains.Conclusions Gene mecA expression in Staphylococcus aureus could be chiefly induced by mecR1,but which in coagulase-ngeative staphylococci could be other factors.The mutation and deletion of mecI were universal phenomenon in clinical strains,there could be a mechanism for overcoming the repressing of resistance caused by mecI in staphylococci.