Yun-Bo Chen1,2, Si-Lan Gu1,2, Ping Shen1,2, Tao Lv1,2, Yun-Hui Fang1,2, Ling-Ling Tang1,2,3, Lan-Juan Li2,1. 1. State Key Laboratory for Diagnosis and Treatment of Infectious Diseases, The First Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, Zhejiang, PR China. 2. Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, Hangzhou, PR China. 3. Hospital Infection-Control Department, The First Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, Zhejiang, PR China.
Abstract
OBJECTIVE: The aim of this study was to perform molecular characterization for and determine the antimicrobial susceptibility profiles of Clostridium difficile collected from hospitals during a 4-year period (2009-2013) in China. METHODS: Strains of toxigenic C. difficile were isolated from patients with diarrhoea, and this was followed by typing using multilocus sequence typing (MLST) and testing for susceptibility to 10 antimicrobials by using the E-test. The mechanisms of resistance to moxifloxacin, erythromycin, clindamycin and tetracycline were investigated by PCR. RESULTS: A total of 405 non-duplicate toxigenic C. difficile isolates were identified, while 31 sequence types (STs) were identified. A predominant type, ST-54, accounted for 20.2 % of the STs, followed by ST-35 (16.3 %) and ST-37 (13.6 %). We found that 6.2 % of the isolates were binary toxin genes-positive, and 83.7 % of these belonged to ST-5. All of the isolates demonstrated 100 % susceptibility to first-line Clostridium difficile infection (CDI) therapies (i.e. metronidazole and vancomycin), while the resistance rates varied for the other antibiotics tested. Two hundred and ninety three (72.3 %) isolates were susceptible to moxifloxacin. All 112 moxifloxacin-resistant isolates had mutations resulting in an amino acid substitution in gryA and/or gyrB. The ermB gene was detected in 86.7 % (241/278) of the erythromycin- and clindamycin-resistant isolates, while the tetM gene was present in 97.1 % (85/87) of the tetracycline-resistant isolates. CONCLUSION: MLST typing revealed a wide variety of STs causing CDI, while ST-54 was the most common ST. All of the isolates were susceptible to metronidazole and vancomycin, while the resistance rates varied for the other antibiotics tested. There were no changes in the trends for the STs and antibiotic susceptibility profiles over 4 years.
OBJECTIVE: The aim of this study was to perform molecular characterization for and determine the antimicrobial susceptibility profiles of Clostridium difficile collected from hospitals during a 4-year period (2009-2013) in China. METHODS: Strains of toxigenic C. difficile were isolated from patients with diarrhoea, and this was followed by typing using multilocus sequence typing (MLST) and testing for susceptibility to 10 antimicrobials by using the E-test. The mechanisms of resistance to moxifloxacin, erythromycin, clindamycin and tetracycline were investigated by PCR. RESULTS: A total of 405 non-duplicate toxigenic C. difficile isolates were identified, while 31 sequence types (STs) were identified. A predominant type, ST-54, accounted for 20.2 % of the STs, followed by ST-35 (16.3 %) and ST-37 (13.6 %). We found that 6.2 % of the isolates were binary toxin genes-positive, and 83.7 % of these belonged to ST-5. All of the isolates demonstrated 100 % susceptibility to first-line Clostridium difficile infection (CDI) therapies (i.e. metronidazole and vancomycin), while the resistance rates varied for the other antibiotics tested. Two hundred and ninety three (72.3 %) isolates were susceptible to moxifloxacin. All 112 moxifloxacin-resistant isolates had mutations resulting in an amino acid substitution in gryA and/or gyrB. The ermB gene was detected in 86.7 % (241/278) of the erythromycin- and clindamycin-resistant isolates, while the tetM gene was present in 97.1 % (85/87) of the tetracycline-resistant isolates. CONCLUSION: MLST typing revealed a wide variety of STs causing CDI, while ST-54 was the most common ST. All of the isolates were susceptible to metronidazole and vancomycin, while the resistance rates varied for the other antibiotics tested. There were no changes in the trends for the STs and antibiotic susceptibility profiles over 4 years.
Authors: Rodrigo Otávio Silveira Silva; Carlos Augusto de Oliveira Júnior; Dominique S Blanc; Silvia Trindade Pereira; Mário Cesar Rennó de Araujo; Artur Vasconcelos; Francisco Carlos Faria Lobato Journal: Anaerobe Date: 2018-04-03 Impact factor: 3.331