ABSTRACT
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).
ABSTRACT
Objective To realize antimicrobial resistance and carrying status of OXA carbapenemase among imi-penem-resistant Acinetobacter baumannii (IRAB)isolated from patients of Hohhot,so as to provide guidance for the prevention and control of healthcare-associated infection(HAI)caused by multidrug-resistant Acinetobacter bauman-nii .Methods 49 IRAB isolates from 3 tertiary first-class hospitals in Hohhot between January and December 2012 were collected,antimicrobial susceptibility testing was performed by Kirby-Bauer disk diffusion method,four geno-types(blaOXA-51-like ,blaOXA-23-like ,blaOXA-24-like ,blaOXA-58-like )of OXA carbapenemase were detected by polymerase chain reaction (PCR).Results All 49 isolated IRAB strains were found to be highly resistant to antimicrobial agents (81 .63%-100.00%)except to minocycline (8.16%);blaOXA-51-like was identified in 49 strains (100.00%),42 (85.71 %)of which also carried blaOXA-23-like gene ,blaOXA-23-lik and blaOXA-51-like were both found in three hospital, blaOXA-24-like and blaOXA-58-like weren’t found.Conclusion IRAB strains present multidrug resistance,resistant to mi-nocycline is the lowest;blaOXA-23-like is the main drug-resistance mechanism of IRAB in Hohhot.