Prevalence of CTX-M extended-spectrum beta-lactamases and sequence type 131 in Korean blood, urine, and rectal Escherichia coli isolates.
A high proportion of extended-spectrum beta-lactamase (ESBL) producing Escherichia coli are of the ST131 lineage, but there are few estimates of ST131 prevalence among ESBL-negative E. coli. Without this information, it is difficult to evaluate the contribution of the ST131 lineage to the emergence and spread of ESBL E. coli. A total of 1658 E. coli isolates were collected at Gachon University Gil Medical Center in Korea from 2006 to 2008. The antibiotic resistance profile was determined for all isolates, and ESBL-positive isolates were screened for the presence of CTX-M-type ESBLs. All ESBL-positive (n=84) and a representative sample of ESBL-negative (n=100) isolates were screened for O25b-ST131 using a PCR-based assay. The isolates were further classified on the basis of fumC and fimH types, which allowed for a comparison of the two typing methods. 5.7% of isolates were ESBL-positive, 87% of which contained CTX-M-type ESBLs. There was no significant difference in the prevalence of ST131 between ESBL-positive and -negative groups; 14% of ESBL-positive isolates and 9% of tested ESBL-negative isolates were ST131 by CH-typing. ST131-positive isolates harbored CTX-M-1-group ESBLs (including CTX-M-15) more frequently than other CTX-M types, and exhibited greater levels of antibiotic resistance than non-ST131 isolates. Furthermore, a number of isolates identified as O25b-ST131 by PCR corresponded to non-ST131 sequence types by CH-typing, emphasizing the need to consider the testing method when comparing reported prevalences of ST131.
Department of Biophysics, University of Michigan, Ann Arbor, MI 48109, United States.
Sarah E
SE
Graham
Department of Epidemiology & Biostatistics, Michigan State University, East Lansing, MI 48824, United States; Department of Microbiology & Molecular Genetics, Michigan State University, East Lansing, MI 48824, United States.
Lixin
L
Zhang
Department of Microbiology, Qauid-i-Azam University, Islamabad, Pakistan; Department of Epidemiology, School of Public Health, University of Michigan, Ann Arbor, MI 48109, United States.
Ihsan
I
Ali
Department of Internal Medicine, Gachon University Gil Medical Center, Incheon, South Korea.
Yong Kyun
YK
Cho
Department of Epidemiology, School of Public Health, University of Michigan, Ann Arbor, MI 48109, United States.
Miriam D
MD
Ismail
Department of Medicinal Chemistry, College of Pharmacy, University of Michigan, Ann Arbor, MI 48109, United States.
Heather A
HA
Carlson
Department of Epidemiology, School of Public Health, University of Michigan, Ann Arbor, MI 48109, United States. Electronic address: bfoxman@umich.edu.
Betsy
B
Foxman
D018830:Adhesins, Escherichia coli / Q000235:genetics* / Q000378:metabolism; D000900:Anti-Bacterial Agents / Q000494:pharmacology; D016470:Bacteremia / Q000188:drug therapy / Q000453:epidemiology* / Q000382:microbiology; D015373:Bacterial Typing Techniques; D024901:Drug Resistance, Multiple, Bacterial / Q000235:genetics; D016521:Electrophoresis, Gel, Pulsed-Field; D004926:Escherichia coli / Q000145:classification / Q000187:drug effects / Q000201:enzymology / Q000235:genetics*; D004927:Escherichia coli Infections / Q000188:drug therapy / Q000453:epidemiology* / Q000382:microbiology; D029968:Escherichia coli Proteins / Q000235:genetics* / Q000378:metabolism; D036781:Fimbriae Proteins / Q000235:genetics* / Q000378:metabolism; D015870:Gene Expression; D006801:Humans; D008826:Microbial Sensitivity Tests; D017720:Molecular Epidemiology; D015995:Prevalence; D012007:Rectum / Q000382:microbiology; D056910:Republic of Korea / Q000453:epidemiology; D001618:beta-Lactamases / Q000235:genetics* / Q000378:metabolism
D018830:Adhesins, Escherichia coli; D000900:Anti-Bacterial Agents; D029968:Escherichia coli Proteins; C058769:fimH protein, E coli; D036781:Fimbriae Proteins; D001618:beta-Lactamases; C000602253:beta-lactamase CTX-M, E coli
CTX-M-15; ESBL; ST131