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First report of the emergence of CTX-M-type extended-spectrum beta-lactamases (ESBLs) as the predominant ESBL isolated in a U.S. health care system.
Antimicrob Agents Chemother. 2007 Nov; 51(11):4015-21.AA

Abstract

CTX-M-type extended-spectrum beta-lactamases (ESBLs) have become increasingly common worldwide, with the notable exception of the United States, where TEM- and SHV-type ESBLs have appeared to predominate. We have noted the emergence of ESBLs in our health care system (the University Health System in San Antonio, TX), especially in Escherichia coli isolates, that preferentially hydrolyze cefotaxime rather than ceftazidime, suggesting the possibility of CTX-M-type enzymes. Microbiology laboratory records were reviewed to identify ESBL-producing isolates and to compare the diameters of ceftazidime disk diffusion zones of inhibition to cefotaxime zone diameters. All isolates had been initially detected and confirmed using the procedures recommended by the Clinical and Laboratory Standards Institute. A total of 94 stored ESBL-producing isolates recovered between January 2000 and June 2006 (predominately from blood and normally sterile fluids) were retrieved for further study and screened using PCR primers specific for the presence of CTX-M, TEM, and SHV ESBLs. Only small numbers of retained ESBL-producing isolates were available for study in 2000 and 2002. The percentages of available ESBL-producing organisms in the following years were found to produce CTX-M enzymes: 2000, 25%; 2001, 10%; 2002, 0%; 2003, 60%; 2004, 69%; 2005, 89%; and 2006, 70%. The most common CTX-M-type ESBL was CTX-M-15, followed by CTX-M-16, CTX-M-8, and CTX-M-14. Comparing the disk diffusion zone diameters of cefotaxime and ceftazidime was helpful with the initial recognition of CTX-M-producing E. coli, which had an average cefotaxime zone diameter 7 mm smaller than the ceftazidime zone. However, comparing ceftazidime and cefotaxime zones for CTX-M-producing Klebsiella spp. was not helpful with initial recognition. CTX-M enzymes were also identified in Proteus mirabilis, Enterobacter spp., and Morganella morganii. Based on pulsed-field gel electrophoresis typing of the E. coli isolates, the CTX-M-producing isolates did not represent the spread of a single clone in the institution or in the community. In conclusion, CTX-M-type ESBLs are now the most common ESBL type isolated from patients in our health care system and may also be present but unrecognized in other U.S. locales.

Authors+Show Affiliations

Department of Pharmacy, University Health System, San Antonio, TX, USA.No affiliation info availableNo affiliation info availableNo affiliation info availableNo affiliation info available

Pub Type(s)

Journal Article
Research Support, U.S. Gov't, Non-P.H.S.

Language

eng

PubMed ID

17724160

Citation

Lewis, James S., et al. "First Report of the Emergence of CTX-M-type Extended-spectrum Beta-lactamases (ESBLs) as the Predominant ESBL Isolated in a U.S. Health Care System." Antimicrobial Agents and Chemotherapy, vol. 51, no. 11, 2007, pp. 4015-21.
Lewis JS, Herrera M, Wickes B, et al. First report of the emergence of CTX-M-type extended-spectrum beta-lactamases (ESBLs) as the predominant ESBL isolated in a U.S. health care system. Antimicrob Agents Chemother. 2007;51(11):4015-21.
Lewis, J. S., Herrera, M., Wickes, B., Patterson, J. E., & Jorgensen, J. H. (2007). First report of the emergence of CTX-M-type extended-spectrum beta-lactamases (ESBLs) as the predominant ESBL isolated in a U.S. health care system. Antimicrobial Agents and Chemotherapy, 51(11), 4015-21.
Lewis JS, et al. First Report of the Emergence of CTX-M-type Extended-spectrum Beta-lactamases (ESBLs) as the Predominant ESBL Isolated in a U.S. Health Care System. Antimicrob Agents Chemother. 2007;51(11):4015-21. PubMed PMID: 17724160.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - First report of the emergence of CTX-M-type extended-spectrum beta-lactamases (ESBLs) as the predominant ESBL isolated in a U.S. health care system. AU - Lewis,James S,2nd AU - Herrera,Monica, AU - Wickes,Brian, AU - Patterson,Jan E, AU - Jorgensen,James H, Y1 - 2007/08/27/ PY - 2007/8/29/pubmed PY - 2008/1/16/medline PY - 2007/8/29/entrez SP - 4015 EP - 21 JF - Antimicrobial agents and chemotherapy JO - Antimicrob Agents Chemother VL - 51 IS - 11 N2 - CTX-M-type extended-spectrum beta-lactamases (ESBLs) have become increasingly common worldwide, with the notable exception of the United States, where TEM- and SHV-type ESBLs have appeared to predominate. We have noted the emergence of ESBLs in our health care system (the University Health System in San Antonio, TX), especially in Escherichia coli isolates, that preferentially hydrolyze cefotaxime rather than ceftazidime, suggesting the possibility of CTX-M-type enzymes. Microbiology laboratory records were reviewed to identify ESBL-producing isolates and to compare the diameters of ceftazidime disk diffusion zones of inhibition to cefotaxime zone diameters. All isolates had been initially detected and confirmed using the procedures recommended by the Clinical and Laboratory Standards Institute. A total of 94 stored ESBL-producing isolates recovered between January 2000 and June 2006 (predominately from blood and normally sterile fluids) were retrieved for further study and screened using PCR primers specific for the presence of CTX-M, TEM, and SHV ESBLs. Only small numbers of retained ESBL-producing isolates were available for study in 2000 and 2002. The percentages of available ESBL-producing organisms in the following years were found to produce CTX-M enzymes: 2000, 25%; 2001, 10%; 2002, 0%; 2003, 60%; 2004, 69%; 2005, 89%; and 2006, 70%. The most common CTX-M-type ESBL was CTX-M-15, followed by CTX-M-16, CTX-M-8, and CTX-M-14. Comparing the disk diffusion zone diameters of cefotaxime and ceftazidime was helpful with the initial recognition of CTX-M-producing E. coli, which had an average cefotaxime zone diameter 7 mm smaller than the ceftazidime zone. However, comparing ceftazidime and cefotaxime zones for CTX-M-producing Klebsiella spp. was not helpful with initial recognition. CTX-M enzymes were also identified in Proteus mirabilis, Enterobacter spp., and Morganella morganii. Based on pulsed-field gel electrophoresis typing of the E. coli isolates, the CTX-M-producing isolates did not represent the spread of a single clone in the institution or in the community. In conclusion, CTX-M-type ESBLs are now the most common ESBL type isolated from patients in our health care system and may also be present but unrecognized in other U.S. locales. SN - 0066-4804 UR - https://www.unboundmedicine.com/medline/citation/17724160/First_report_of_the_emergence_of_CTX_M_type_extended_spectrum_beta_lactamases__ESBLs__as_the_predominant_ESBL_isolated_in_a_U_S__health_care_system_ L2 - http://aac.asm.org/cgi/pmidlookup?view=long&pmid=17724160 DB - PRIME DP - Unbound Medicine ER -