title: Molecular Epidemiology of Clostridium difficile Infection in a Large Teaching Hospital in Thailand.
abstract: Clostridium difficile infection (CDI) is a leading cause of healthcare-associated morbidity and mortality worldwide. In Thailand, CDI exhibits low recurrence and mortality and its molecular epidemiology is unknown. CDI surveillance was conducted in a tertiary facility (Siriraj Hospital, Bangkok). A total of 53 toxigenic C. difficile strains from Thai patients were analyzed by multi-locus sequence typing (MLST), PCR ribotyping, and pulse-field gel electrophoresis (PFGE). The mean age of the cohort was 64 years and 62.3% were female; 37.7% of patients were exposed to > two antibiotics prior to a diagnosis of CDI, with beta-lactams the most commonly used drug (56.3%). Metronidazole was used most commonly (77.5%; success rate 83.9%), and non-responders were treated with vancomycin (success rate 100%). None of the isolates carried binary toxin genes. Most isolates (98.2-100%) were susceptible to metronidazole, vancomycin, tigecycline and daptomycin. There were 11 sequence types (STs), 13 ribotypes (RTs) and four PFGE types. Six previously identified STs (ST12, ST13, ST14, ST33, ST41 and ST45) and five novel STs unique to Thailand (ST66, ST67, ST68, ST69 and ST70) were identified. PCR RTs UK 017 (ST45) (45.3%) and UK 014/020 (ST33) (24.5%) were the most common. High concordance was observed between the MLST and ribotyping results (p<0.001). C. difficile isolates from Thai patients were highly susceptible to standard antimicrobial agents. In conclusion, the five STs indicate the high genetic diversity and unique polymorphisms in Thailand. Moreover, the emergence of antimicrobial resistance to vancomycin warranted continuous surveillance to prevent further spread of the toxigenic C. difficile isolates.
authors.affiliation: Department of Microbiology, Faculty of Medicine, Siriraj Hospital, Mahidol University, Bangkok, Thailand.
authors.forename: Popchai
authors.initials: P
authors.lastname: Ngamskulrungroj
authors.affiliation: Department of Microbiology, Faculty of Medicine, Siriraj Hospital, Mahidol University, Bangkok, Thailand.
authors.forename: Sittinee
authors.initials: S
authors.lastname: Sanmee
authors.forename: Papanin
authors.initials: P
authors.lastname: Putsathit
authors.affiliation: School of Pathology & Laboratory Medicine, The University of Western Australia, Crawley, Australia.
authors.forename: Papanin
authors.initials: P
authors.lastname: Pusathit
authors.affiliation: Department of Microbiology, Faculty of Medicine, Siriraj Hospital, Mahidol University, Bangkok, Thailand.
authors.forename: Pipat
authors.initials: P
authors.lastname: Piewngam
authors.affiliation: School of Pathology & Laboratory Medicine, The University of Western Australia, Crawley, Australia.
authors.forename: Briony
authors.initials: B
authors.lastname: Elliott
authors.affiliation: School of Pathology & Laboratory Medicine, The University of Western Australia, Crawley, Australia; PathWest Laboratory Medicine WA, Queen Elizabeth II Medical Centre, Nedlands, Australia.
authors.forename: Thomas V
authors.initials: TV
authors.lastname: Riley
authors.affiliation: Department of Microbiology, Faculty of Medicine, Siriraj Hospital, Mahidol University, Bangkok, Thailand.
authors.forename: Pattarachai
authors.initials: P
authors.lastname: Kiratisin
mesh_terms: D016360:Clostridioides difficile / Q000235:genetics* / Q000302:isolation & purification; D003015:Clostridium Infections / Q000453:epidemiology*; D003428:Cross Infection / Q000453:epidemiology*; D004761:Enterocolitis, Pseudomembranous / Q000453:epidemiology; D006784:Hospitals, Teaching; D006801:Humans; D017720:Molecular Epidemiology; D008969:Molecular Sequence Data; D058885:Multilocus Sequence Typing; D021521:Ribotyping; D013785:Thailand