title: Comparative epidemiology of CTX-M-14 and CTX-M-15 producing Escherichia coli: association with distinct demographic groups in the community in New Zealand.
abstract: Extended spectrum beta-lactamase producing E. coli (ESBL-EC) are an emerging public health issue. In New Zealand (NZ), bla (CTX-M-14) and bla (CTX-M-15) are the most common ESBL genes. Although many studies describe risk factors for ESBL-EC, few describe risk factors for specific ESBL genes. Between January 2006 and December 2007, we characterized 108 consecutive, non-duplicate isolates of ESBL-EC at the Auckland Hospital laboratory. Demographic and clinical data were recorded. Of the 108, 54.6% (59) were CTX-M-15-EC, 26.9% (29) were CTX-M-14-EC and 12.09% were CTX-M-9 (13). The remaining seven isolates carried CTX-M-3 (3; 2.7%), CTX-M-65 (2; 1.8%), CTX-M-27 (1; 0.9%) and CTX-M-57 (1; 0.9%). CTX-M-15-EC were more likely than CTX-M-14-EC to be fluoroquinolone-resistant (86.4% versus 32.4%; p=0.006) and to be non-susceptible to amoxicillin-clavulanate (84.7% versus 41.4%; p=0.0001). Patients with CTX-M-15-EC were more likely to be of Indian ethnicity (34.5% versus 0%; p=0.0012) and to have travelled recently (31.6% versus 4%; p=0.0088). Patients with CTX-M-14-EC were more likely to have Chinese or South-East Asian ethnicity (48.1% versus 5.2%; p<0.0001) and to have no history of either travel or prior hospital admission (44% versus 8.9%; p=0.0006). These data imply that CTX-M-15 and CTX-M-14 producing E. coli are associated with distinct demographic subgroups in NZ.
authors.affiliation: Department of Clinical Microbiology, Auckland City Hospital, Auckland District Health Board, Auckland, New Zealand. JoshuaF@adhb.govt.nz
authors.forename: J T
authors.initials: JT
authors.lastname: Freeman
authors.forename: D A
authors.initials: DA
authors.lastname: Williamson
authors.forename: H
authors.initials: H
authors.lastname: Heffernan
authors.forename: M
authors.initials: M
authors.lastname: Smith
authors.forename: J E
authors.initials: JE
authors.lastname: Bower
authors.forename: S A
authors.initials: SA
authors.lastname: Roberts
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000900:Anti-Bacterial Agents / Q000494:pharmacology; D017714:Community-Acquired Infections / Q000453:epidemiology / Q000382:microbiology; D003710:Demography; D024881:Drug Resistance, Bacterial; D004926:Escherichia coli / Q000201:enzymology* / Q000302:isolation & purification; D004927:Escherichia coli Infections / Q000453:epidemiology* / Q000382:microbiology*; D005006:Ethnicity; D005260:Female; D024841:Fluoroquinolones / Q000494:pharmacology; D006801:Humans; D008297:Male; D008875:Middle Aged; D009520:New Zealand / Q000453:epidemiology; D012307:Risk Factors; D055815:Young Adult; D001618:beta-Lactamases / Q000378:metabolism*
chemical_list: D000900:Anti-Bacterial Agents; D024841:Fluoroquinolones; C456080:beta-lactamase CTX-M-14; C473109:beta-lactamase CTX-M-15; D001618:beta-Lactamases