Ulzii Orshikh LuvsansharavItaru HiraiMarie NikiTadahiro SasakiKiyoko MakimotoChalit KomalamisraWanna MaipanichTeera KusolsukSurapol Sa-NguankiatSomchit PubampenYoshimasa YamamotoOsaka University Faculty of MedicineKobe University School of MedicineMahidol University2018-05-032018-05-032011-05-01Journal of Medical Microbiology. Vol.60, No.5 (2011), 619-624002226152-s2.0-79955674618https://repository.li.mahidol.ac.th/handle/123456789/12055The prevalence of and risk factors associated with extended-spectrum β-lactamase (ESBL)-producing micro-organisms have not been well studied in healthy individuals. The aim of this study was to determine this in healthy individuals in Thailand. Stool samples and questionnaires obtained from 445 participants from three provinces in Thailand were analysed. The antimicrobial susceptibility of the isolates was assessed using phenotypic and genotypic methods. PCR analysis was performed to detect and group the bla CTX-M genes. The prevalence of CTX-M-type ESBL-producing Enterobacteriaceae in the three provinces was as follows: 29.3% in Nan (43/147), 29.9% in Nakhon Si Thammarat (43/144) and 50.6% in Kanchanaburi (78/154) (P < 0.001). Of the 445 samples, 33 (7.4%), 1 (0.2%) and 127 (28.5%) isolates belonged to the bla CTX-M gene groups I, III and IV, respectively. Escherichia coli was the predominant member of the Enterobacteriaceae producing CTX-M-type ESBLs (40/43, 39/43 and 70/78 isolates in Nan, Nakhon Si Thammarat and Kanchanaburi, respectively). No statistically significant association was observed between the presence of ESBL-producing bacteria and gender, age, education, food habits or antibiotic usage. However, the provinces that had the highest prevalence of ESBLproducing Enterobacteriaceae also had the highest prevalence of use and purchase of antibiotics without a prescription. Thus, this study revealed that faecal carriage of ESBL-producing Enterobacteriaceae is very high in asymptomatic individuals in Thailand, with some variations among the provinces. This high prevalence may be linked to antibiotic abuse. © 2011 SGM.Mahidol UniversityImmunology and MicrobiologyMedicineArticleSCOPUS10.1099/jmm.0.026955-0