Isolation, Identification and Drug Sensitivity Anlysis of Corynebacterium glucuronolyticum from Urinary Tract / 中国药房

ABSTRACT

OBJECTIVE: To identify and analyze drug sensitivity of Corynebacterium glucuronolyticum iscolated from clinic, and to provide reference for clinical drug use. METHODS: Two strains isolated from the urine specimens of urolithiasis-induced urinary tract infection patients in our hospital were inoculated into Columbia blood plate and the MacConkey plate. The growth of strains was observed and counted. Protein mass spectrometry of strains was detected by MALDI-TOF-MS. DNA of strains was extracted, and PCR was used to amplify the 16S ribosome RNA (rRNA) sequence. Bi-directional sequencing of 1 500 bp target bands was conducted. Blast comparison between it and GenBank database was conducted to identify bacterial strain. Drug resistance of 2 strains was monitored by Etest assay. RESULTS: Two strains grew on the Columbia blood plate (with colony forming unit ＞105 CFU/mL) and did not grow on the MacConkey plate. Two strains were Gram-positive Corynebacterium and showed palisading or eight type arrangement. Two strains were C. glucuronolyticum by MALDI-TOF-MS identification, with reliability of 99. 9％. The characteristic peaks of m/z 2 431, 3 089, 3 364, 3 378, 4 200, 5 508, 6 302, 6 637, 6 730, 6 946, 12 603 appeared. Blast comparison showed that the sequence homology of 2 strains compared with C. glucuronolyticum strain known in GenBank were higher than 98 ％. Results of drug sensitivity test showed that strain 1 was resistant to ceftriaxone and ciprofloxacin, and sensitive to 14 other antibiotics as penicillin G; strain 2 was resistant to ceftriaxone, erythromycin, ciprofloxacin, tetracycline and clindamycin, moderately sensitive to cefotaxime, and sensitive to 10 other antibiotics. CONCLUSIONS: Two strains are C. glucuronolyticum, and drug resistance of them to commonly used antibiotics is different. The strains are rare pathogen of urinary tract and show multidrug resistance. Antibiotics should be selected according to the results of strain identification and drug sensitivity test.