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.

Characterization of antibiogram fingerprints in Listeria monocytogenes recovered from irrigation water and agricultural soil samples

“…The multiple antibiotic-resistant phenotypes (MARPs) of L. monocytogenes were evaluated for isolates that exhibited resistance to three or more antibiotics according to the method adapted from [39]. The MDR pattern, amount of antibiotics the isolates exhibited resistance to, and the number of the observed phenotypic pattern were also described.…”

“…The MDR pattern, amount of antibiotics the isolates exhibited resistance to, and the number of the observed phenotypic pattern were also described. Also, the MARI for each multidrug isolate was generated using the mathematical equation adapted from [39] which is given as:…”

Antibiotic resistance profiles of Escherichia coli O26, O145, and O157:H7 isolated from swine in the Eastern Cape Province, South Africa

“…The reaction mixture comprised of 12.5 µL 2× PCR master mix (Thermo Scientific, USA), 1 µL of 10 pmol each of the forward and reverse primers (F: 5'-CTGGAAGAGGCTAGCCTGGACGAG-3') and (R: 5'-AAAATCGGCACCGGTGGAGCGATC-3'), respectively, 5 µL of DNA template and nuclease-free water to a total volume of 25 µL. The PCR conditions for uidA amplification were as described elsewhere [20] with slight adjustment as follows: initial denaturation at 94 °C for 5min, which was followed by 35 cycles of 30 s denaturation at 95 °C , primer annealing at 58 °C for 1 min, extension at 72 °C for 1 min and final extension at 72 °C for 8 min. The PCR amplicons (5 µL) were verified on 1.5% agarose gel (Separations, South Africa) stained with ethidium bromide (0.001 µg/mL), and electrophoresed at 100 V for 60 min along in a 0.5× Tris-borate-EDTA buffer, with a 100 bp ladder , and then visualized under UV transilluminator (Alliance 4.7).…”

Multidrug resistance and high prevalence of class 1 integrons in Escherichia coli isolated from waters and vegetables in Nsukka and Enugu, Nigeria

“…Multidrug resistance (MDR) has been frequently reported in Nigeria among E. coli isolates obtained from human specimens [12, 37, 42, 43], animal sources [36] and environmental samples [38, 42, 44, 45]. In the present study, all the isolates were multidrug resistant, ranging from 5-drug to 16-drug resistance patterns.…”