| Objectives:To investigate the antibiotics-resistance status of E. cloacae and to study the characteristic of clinical distribution, resistance mechanism and resistance transmission mechanism of Carbapenem-Resistant E. cloacae, in order to contribute to the control of nosocomial infection and the reasonable application of antibiotics.Methods:A retrospective analysis was performed to review strains of clinical infection, their distribution, specimen source and resistance situation, especially to learn the clinical situation of E. cloacae, during the years of2009-2011. E.cloacae was identified by the GNI cards on Vitek auto-microbiology analysis system. Antibioties sensitivity tests were performed using GNS cards.Then the Carbapenem-Resistant E.cloacae was studied furtherly. MICs were determined with standard procedures. Isoelectric focusing of cell extracts was used for detection of β-lactamases. PCR assays with primers specific for the blaIMP-26gene and the conserved segments of class1integrons and sequence analyses were carried out to identify the gene and to map the metallo-(3-lactamase encoding integron. Transferability of the gene was assessed with conjugation experiments. To identify the location of the blaTEM-104gene, conjugation experiments and plasmid electrophoresis were carried out, amplified by PCR.Results:During the time of2009.9-2010.12,1419strains of gram-negative bacterium were separated from the ward of our hospital. Among them, there are469strains E.coli accounting for the first (33.05%),465strains Klebsiella pneumoniae (32.77%) taking the second place,100strains E.cloacae (7.04%) accounting for the fifth place. All the gram-negative bacteria were seperated from the patient’s sputum, urine, blood, pus, secretion and throat swabs, of these1008strains (71.04%,1008/1419)came from sputum;134strains (9.44%,134/1419) came from pus, etc. E.cloacae mainly seperated from sputum (82%,82/100).Intensive care unit has the highest relevance ratio with369strains (26.00%); the second is the department of respiration with285strains (20.08%); Division of Neonatology has208strains (14.66%); general surgery department has160strains (11.28%), etc. And E. cloacae mainly seperated from Division of Neonatology accounting for22%(22/100), Intensive care unit and department of respiration taken up20%(20/100), respectively. The sensitive rates of imipenem, meropenem, amikacin, levofloxacin gentamycin and levofloxacin to E. cloacae remained high (>90%). Cefoperazone/sulbactam, piperacillin/sulbactam and cefepime to E. cloacae were also sensitive.A carbapenem-resistant E. cloacae was found to carry IMP-26metallo-β-lactamase inclass1integron and TEM-104extended-spectrum P-lactamase in conjugative plasmid.Conclusions:(1) The type of IMP-26Metallo-β-lactamase was firstly reported in Singapore, carried by a strain of pseudomonas aeruginosa. It is rare in foreign and has not been reported in our country. It is the first time to detect E. cloacae carrying IMP-26Metallo-β-lactamase.(2) IMP-26Metallo-β-lactamase is the mutant strain of IMP-4. IMP-4is very popular in domestic, therefore we should to strengthen the management of the mutations.(3) It is the first time to find IMP-26captured by integron, which may has very important clinical significance. |
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