title: Multiple antibiotic resistance indexing of Escherichia coli to identify high-risk sources of faecal contamination of water.
abstract: We evaluated the antibiogram profile of Escherichia coli (n = 300) isolated from selected rivers in Osun State, Nigeria. The identities of the E. coli isolates were confirmed by polymerase chain reaction (PCR) technique. Susceptibility of the isolates to 20 antibiotics conventionally used in clinical cases was assessed in vitro by the standardized agar disc-diffusion method. All the isolates were susceptible to imipenem, meropenem, amikacin and gatilofloxacin. The isolates were variously susceptible to the other antibiotics as follows: ciprofloxacin (96 %), kanamycin (95 %), neomycin (92 %), streptomycin (84 %), chloramphenicol (73 %), nalidixic acid (66 %), nitrofurantoin (64 %), gentamycin (63 %), doxycycline (58 %), cefepime (57 %), tetracycline (49 %) and cephalothin (42 %). The multiple antibiotic resistance indexing ranged from 0.50 to 0.80 for all the sampling locations and exceeded the threshold value of 0.2, suggesting the origin of the isolates to be of high antimicrobial usage. Our findings signify an increase in the incidence of antimicrobial resistance of E. coli towards conventionally used antibiotics necessitating proper surveillance programmes towards the monitoring of antimicrobial resistance determinants in water bodies.
authors.affiliation: Applied and Environmental Microbiology Research Group, Department of Biochemistry and Microbiology, University of Fort Hare, Alice, 5700, South Africa, olayinkatemi@yahoo.co.uk.
authors.forename: Yinka
authors.initials: Y
authors.lastname: Titilawo
authors.forename: Timothy
authors.initials: T
authors.lastname: Sibanda
authors.forename: Larry
authors.initials: L
authors.lastname: Obi
authors.forename: Anthony
authors.initials: A
authors.lastname: Okoh
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D004269:DNA, Bacterial / Q000235:genetics; D024901:Drug Resistance, Multiple, Bacterial; D004784:Environmental Monitoring / Q000379:methods; D004926:Escherichia coli / Q000187:drug effects* / Q000235:genetics / Q000302:isolation & purification; D005243:Feces / Q000382:microbiology*; D008826:Microbial Sensitivity Tests; D009549:Nigeria; D016133:Polymerase Chain Reaction; D045483:Rivers; D013752:Tetracycline; D014871:Water Microbiology; D014873:Water Pollutants / Q000302:isolation & purification
chemical_list: D000900:Anti-Bacterial Agents; D004269:DNA, Bacterial; D014873:Water Pollutants; D013752:Tetracycline