Characteristics of gram-negative urinary tract infections caused by extended spectrum beta lactamases: pivmecillinam as a treatment option within South Dublin, Ireland.
BACKGROUND
The prevalence of urinary tract infections (UTIs) caused by extended-spectrum β-lactamase (ESBL)-producing Enterobacteriaceae is increasing and the therapeutic options are limited, especially in primary care. Recent indications have suggested pivmecillinam to be a suitable option. This pilot study aimed to assess the viability of pivmecillinam as a therapeutic option in a Dublin cohort ﻿of mixed community and healthcare origin﻿.


METHODS
A prospective measurement of mean and fractional inhibitory concentrations of antibiotic use in 95 patients diagnosed with UTI caused by ESBL-producing Enterobacteriaceae was carried out. 36 % patients were from general practice, 40 % were admitted to hospital within south Dublin, and 25 % samples arose from nursing homes. EUCAST breakpoints were used to determine if an isolate was sensitive or resistant to antibiotic agents.


RESULTS
Sixty-nine percent of patients (N = 66) with urinary ESBL isolates were female. The mean age of females was 66 years compared with a mean age of 74 years for males. Thirty-six percent of isolates originated from primary care, hospital inpatients (26 %), and nursing homes (24 %). The vast majority of ESBL isolates were E. coli (80 %). The E tests for mecillinam and co-amoxiclav had concentration ranges from 0.16 mg/L up to 256 mg/L. The mean inhibitory concentration (MIC) of mecillinam ranged from 0.25 to 256 mg/L, while co-amoxiclav MICs ranged from 6 to 256 mg/L. The percentage of isolates resistant to mecillinam and co-amoxiclav was found to be 5.26 and 94.74 % respectively.


CONCLUSIONS
This is the first study exploring the use of pivmecillinam in an Irish cohort and has demonstrated that its use in conjunction with or without co-amoxiclav is an appropriate and useful treatment for urinary tract infections caused by ESBL-producing organisms.
Department of Urological Surgery, AMNCH, Tallaght Hospital, Dublin 24, Ireland.
Fardod
F
O'Kelly
Department of Clinical Microbiology, AMNCH, Tallaght Hospital, Dublin 24, Ireland.
Siobhan
S
Kavanagh
Department of Urological Surgery, AMNCH, Tallaght Hospital, Dublin 24, Ireland.
Rustom
R
Manecksha
Department of Urological Surgery, AMNCH, Tallaght Hospital, Dublin 24, Ireland.
John
J
Thornhill
Department of Clinical Microbiology, AMNCH, Tallaght Hospital, Dublin 24, Ireland. jfennell@tcd.ie.
Jérôme P
JP
Fennell
D000368:Aged; D000560:Amdinocillin / Q000494:pharmacology / Q000627:therapeutic use; D000561:Amdinocillin Pivoxil / Q000494:pharmacology / Q000627:therapeutic use*; D019980:Amoxicillin-Potassium Clavulanate Combination / Q000494:pharmacology / Q000627:therapeutic use; D000900:Anti-Bacterial Agents / Q000494:pharmacology / Q000627:therapeutic use*; D024881:Drug Resistance, Bacterial; D004926:Escherichia coli / Q000187:drug effects / Q000378:metabolism / Q000502:physiology; D004927:Escherichia coli Infections / Q000188:drug therapy* / Q000382:microbiology; D005260:Female; D058006:General Practice; D006090:Gram-Negative Bacteria / Q000187:drug effects / Q000378:metabolism / Q000502:physiology; D016905:Gram-Negative Bacterial Infections / Q000188:drug therapy / Q000382:microbiology; D006760:Hospitalization; D006761:Hospitals; D006801:Humans; D007494:Ireland; D007710:Klebsiella Infections / Q000188:drug therapy* / Q000382:microbiology; D007711:Klebsiella pneumoniae / Q000187:drug effects / Q000378:metabolism / Q000502:physiology; D008297:Male; D008826:Microbial Sensitivity Tests; D009735:Nursing Homes; D010865:Pilot Projects; D015995:Prevalence; D011446:Prospective Studies; D012307:Risk Factors; D014552:Urinary Tract Infections / Q000188:drug therapy* / Q000382:microbiology; D001618:beta-Lactamases / Q000378:metabolism
D000900:Anti-Bacterial Agents; D000561:Amdinocillin Pivoxil; D019980:Amoxicillin-Potassium Clavulanate Combination; D001618:beta-Lactamases; D000560:Amdinocillin
Antibiotic resistance; Escherichia coli; Extended-spectrum beta lactamase; Mean inhibitory concentration; Pivmecillinam; Urinary tract infection