Study of carbapenem-resistant genes in a strain of Myroides odoratimimus and clinical therapy for its infection / 中华临床感染病杂志

ABSTRACT

Objective To study carbapenem-resistant genes in a Myroides odoratimimus strain and clinical therapy.Methods A strain of Myroides odoratimimus was isolated from nephrostomy drainage fluid of a patient with urinary tract infection in Xinhua Hospital in May 2013.MicroflexTM MALDI-TOF MS and 16S rDNA sequencing were performed for strain identification.Vitek-2 Compact combined with E-test method was used for antibiotic susceptibility test.Modified Hodge test and imipenem/imipenem-inhibitor (IP/IPI)E-test were performed for drug-resistant phenotype screening.Carbapenemase genes blaMUS-1,blaVIM-1,blaVIM-2,blaIMP-1,blaIMP-2,blaNDM-1,blaOXA-48 and blaGESwere amplified by PCR,and the positive products were sequenced and analyzed.Results The isolated strain was identified as Myroides odoratimimus.The strain was resistant to 17 antibacterial agents,and the minimum inhibitory concentration (MIC) of imipenem was ≥ 16 μg/mL,while it was sensitive to minocycline (MIC =0.38 μg/mL) and intermediate to meropenem (MIC =6 μg/mL).It was negative in modified Hodge test but positive in IP/IPI E-test (IP/IPI≥ 8).blaMUS-1 gene was detected by PCR,and further confirmed by sequencing.Meropenem combined with minocycline was effective for the patient.Conclusion Carbapenem-resistance in this Myroides odoratimimus strain may be related to blaMUS-1 gene,and appropriate therapy for its infection should be based on the result of antibiotic susceptibility test.