Enumeration and characterization of antimicrobial-resistant Escherichia coli bacteria in effluent from municipal, hospital, and secondary treatment facility sources.
We describe a modification of the most probable number (MPN) method for rapid enumeration of antimicrobial-resistant Escherichia coli bacteria in aqueous environmental samples. E. coli (total and antimicrobial-resistant) bacteria were enumerated in effluent samples from a hospital (n = 17) and municipal sewers upstream (n = 5) and downstream (n = 5) from the hospital, effluent samples from throughout the treatment process (n = 4), and treated effluent samples (n = 13). Effluent downstream from the hospital contained a higher proportion of antimicrobial-resistant E. coli than that upstream from the hospital. Wastewater treatment reduced the numbers of E. coli bacteria (total and antimicrobial resistant); however, antimicrobial-resistant E. coli was not eliminated, and E. coli resistant to cefotaxime (including extended-spectrum beta-lactamase [ESBL] producers), ciprofloxacin, and cefoxitin was present in treated effluent samples.
Galvin
Sandra
S
Department of Bacteriology, Clinical Science Institute, National University of Ireland, Galway, Ireland. s.galvin1@nuigalway.ie
Boyle
Fiona
F
Hickey
Paul
P
Vellinga
Akke
A
Morris
Dearbháile
D
Cormican
Martin
M
D015169:Colony Count, Microbial / Q000379:methods*; D024881:Drug Resistance, Bacterial; D004926:Escherichia coli / Q000187:drug effects* / Q000302:isolation & purification*; D005191:Family Characteristics; D006761:Hospitals; D012722:Sewage / Q000382:microbiology*; D018508:Water Purification
D012722:Sewage