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OBJECTIVE: To analyze carbapenemases genotype of imipenem-resistant Gram-negative bacilli in intensive care unit (ICU) of 3 third grade class A hospitals from Qingdao area, so as to provide reference for drug-resistant bacteria infection prevention and treatment in clinic. METHODS: From Jan. 2013 to Jun. 2016, each 60 strains of imipenem-resistant Klebsiella pneumoniae (IRKP), imipenem-resistant Pseudomonas aeruginosa (IRPA) and imipenem-resistant Acinetobacter baumanii (IRAB) were collected from 3 third grade class A hospitals from Qingdao area. Drug sensitivity test was performed by using Kirby-Bauer method. Phenotypes of carbapenemases were determined by Carba NP trial. PCR was applied to amplify carbapenemase gene; Sanger seqnencing method was adopted for bi-directional sequencing; Blast comparison with GenBank database was conducted. RESULTS: Three kinds of imipenem-resistant Gram-negative bacilli showed high drug resistance to majority commonly used antibiotics as piperacillin, cefazolin, imipenem and cilastatin sodium, gentamicin, etc., but were sensitive to polymyxin B (resistance rate of 0). Among 180 drug-resistant strains, there were 52 strains of class A carbapenems, 13 strains of class B carbapenems and 39 strains of class D carbapenems; the detection rates of them were 28. 89％, 7. 22％ and 21. 67％, respectively. There were 52 strains of KPC-2 gene (IRKP), 4 strains of IMP-1 gene (IRPA), 8 strains of VIM-2 gene (7 strains of IRPA, 1 strain of IRAB), 39 strains of OXA-23 gene (IRAB); the detection rates of them were 28. 89％, 2. 22％, 4. 44％, 21. 67％; all strains were not detected 1MP-2, VIM-1, NDM-1, OXA-24, OXA-58 genes. Results of Blast comparison showed that above detected genes were absolutely homology with the corresponding genes in GenBank database. CONCLUSIONS: Drug resistance of imipenem-resistant Gram-negative bacilli in ICU of 3 third grade class A hospitals is serious in this region, which are nearly no-sensitive to most of commonly used antibiotics in clinic. Main genotypes included KPC-2 (K. pneumoniae), OXA-23 (A. baumanii) and IMP-1 and VIM-2 (P. aeruginosa).
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OBJECTIVE To study antibiotic-resistant phenotypes and genotypes of ESBLs-producing Escherichia coli,Klebsiella pneumoniae and Klebsiella oxytoca isolated from children with pneumonia in Urumqi,to know the distribution and difference of these three Gram-negative bacilli from 2003 to 2007.METHODS Bacterial strains were identified by VITEK32,ESBLs were detected by confirmatory test recommended by CLSI.Microarray technique was used to determine the genotypes of ESBLs.RESULTS Antibiotic-resistant phenotypes showed ESBLs-producing K.oxytoca decreasing from 84.3% to 35.3%,K.pneumoniae stabling in 50-60%,E.coli increasing from 34.4% to 72.1% during the five years;genotypes indicated there were most of ctx-m-9 and tem+ctx-m-9 in E.coli,tem and shv in K.pneumoniae,and the most of tem+ctx-m-3 in K.oxytoca.CONCLUSIONS There is high percentage of ESBLs production from children in Urumqi;resistant phenotypes and genotypes of ESBLs are different in three Gram-negative bacilli;and must further enhance the regional epidemiology surveillance about ESBLs.
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OBJECTIVE To investigate the phenotypical and genotypical characteristics of the ?-lactamase in the 302 strains of Gram-negative bacilli,and assess the characteristics of the drug resistance.METHODS The phenotypes of ?-lactamase were detected in the Gram-negative bacilli by disc diffusion screen test,which were further ascertained by disc diffusion confirmatory test,a cefoxitin three dimensional test,and metallo ?-lactamases double-disc synergy test.The ?-lactamases were detected by multiple PCR amplification,then DNA product was sequenced.Antibiotics susceptibility was detected by K-B method.RESULTS Among the clinical Gram-negative isolates,a total of 26.49%(80/302)strains′ ?-lactamases phenotypes were positive,ESBLs,ESBLs combined with AmpC enzyme,ESBLs combined with AmpC enzyme and MBL,and AmpC enzyme producing strains were found in 16.56%,6.62%,1.66% and 0.66%,respectively.A total of 24.83% strains′?-lactamases phenotypes were positive,strains produced ESBLs,ESBLs combined with AmpC enzyme,ESBLs combined with AmpC enzyme and MBL,and AmpC enzyme producing strains were found in 17.55%,6.95%,0.33%,and 0.33%,respectively.Drug-sensitivity test showed multi-resistant Gram-negative isolates were more sensitive to amikacin(18.75%),and heavier resistant to ampicillin(97.50%).CONCLUSIONS ?-Lactamase producing Gram-negative bacilli are resistant to multi-antibiotics.