title: High Prevalence of CTX-M Beta-Lactamases in Enterobacteriaceae from Healthy Individuals in Guangzhou, China.
abstract: This study aimed to determine the prevalence of extended-spectrum beta-lactamases (ESBLs) in Enterobacteriaceae and to characterize the genetic composition of ESBL determinants among Enterobacteriaceae isolates from healthy people in Guangzhou, China. A total of 200 rectal swab samples were collected from healthy asymptomatic individuals and tested for ESBL production using ChromID ESBL agar. Phenotypic ESBL producers were screened for blaCTX-M, blaTEM, and blaSHV genes using PCR and DNA sequencing. The prevalence of ESBL-producing Enterobacteriaceae among rectal swab samples was 69.5%. All ESBL-producing isolates harbored blaCTX-M genes (n=138) except for one isolate that harbored blaSHV-2a. Eleven CTX-M ESBL genes were detected. The most predominant CTX-M-type genes were blaCTX-M-14 (n=82), followed by blaCTX-M-55 (n=19), blaCTX-M-65 (n=10), and blaCTX-M-27 (n=9). Isolates carrying blaCTX-M-38,-3,-15,-14b,-98,-121 and -123 were also identified. Molecular homology analysis of the selected isolates was performed by phylogenetic grouping and multilocus sequence typing and indicated that the predominant clone belonged to A-CC10. This study showed a high rate of CTX-M-type ESBL genes among Enterobacteriaceae isolates from healthy individuals in China.
authors.affiliation: 1 Microbiology Test Laboratory , Guangzhou Center for Disease Control and Prevention, Guangzhou, China .
authors.forename: Yong
authors.initials: Y
authors.lastname: Zhou
authors.affiliation: 1 Microbiology Test Laboratory , Guangzhou Center for Disease Control and Prevention, Guangzhou, China .
authors.forename: Xinwei
authors.initials: X
authors.lastname: Wu
authors.affiliation: 1 Microbiology Test Laboratory , Guangzhou Center for Disease Control and Prevention, Guangzhou, China .
authors.forename: Jing
authors.initials: J
authors.lastname: Zhang
authors.affiliation: 1 Microbiology Test Laboratory , Guangzhou Center for Disease Control and Prevention, Guangzhou, China .
authors.forename: Xia
authors.initials: X
authors.lastname: Tao
authors.affiliation: 1 Microbiology Test Laboratory , Guangzhou Center for Disease Control and Prevention, Guangzhou, China .
authors.forename: Zhiai
authors.initials: Z
authors.lastname: Deng
authors.affiliation: 1 Microbiology Test Laboratory , Guangzhou Center for Disease Control and Prevention, Guangzhou, China .
authors.forename: Yushan
authors.initials: Y
authors.lastname: Hu
authors.affiliation: 1 Microbiology Test Laboratory , Guangzhou Center for Disease Control and Prevention, Guangzhou, China .
authors.forename: Meixia
authors.initials: M
authors.lastname: Li
authors.affiliation: 2 Department of Biochemistry, Zhongshan Medical School, Sun Yat-sen University , Guangzhou, China .
authors.forename: Xia
authors.initials: X
authors.lastname: Yang
authors.affiliation: 1 Microbiology Test Laboratory , Guangzhou Center for Disease Control and Prevention, Guangzhou, China .
authors.forename: Ming
authors.initials: M
authors.lastname: Wang
authors.affiliation: 1 Microbiology Test Laboratory , Guangzhou Center for Disease Control and Prevention, Guangzhou, China .
authors.forename: Zhicong
authors.initials: Z
authors.lastname: Yang
mesh_terms: D000328:Adult; D000368:Aged; D000900:Anti-Bacterial Agents / Q000494:pharmacology; D002681:China / Q000453:epidemiology; D004269:DNA, Bacterial / Q000235:genetics; D004755:Enterobacteriaceae / Q000201:enzymology*; D005260:Female; D005838:Genotype; D064368:Healthy Volunteers; D006801:Humans; D008297:Male; D008826:Microbial Sensitivity Tests; D008875:Middle Aged; D016133:Polymerase Chain Reaction; D015995:Prevalence; D062486:Public Health Surveillance; D012007:Rectum / Q000382:microbiology; D055815:Young Adult; D001618:beta-Lactamases / Q000235:genetics*
chemical_list: D000900:Anti-Bacterial Agents; D004269:DNA, Bacterial; D001618:beta-Lactamases