Occurrence of multidrug resistant and extended spectrum β-lactamase (ESBL) - producing Escherichia coli in wastewater of two healthcare facilities in Ibadan, Nigeria

Most industries in developing countries of the world, especially hospitals and other clinical settings, lack wastewater treatment facilities, and as such, untreated wastewater from their operations are discharged into water bodies without any form of treatment. This study aimed at the antibiotic sensitivity profile and ESBL production in E. coli isolated from untreated hospital wastewater before discharge into the environment. Untreated wastewater from two hospitals, a State Government-owned hospital (SGH) and a privately-owned hospital (POH) with no wastewater treatment facilities were sampled for a period of four months. Isolation of E. coli was carried out using the pour plate technique on Eosin Methylene Blue agar, while identification was carried out using conventional methods. Determination of ESBL production was done by means of the Double Disc Synergy Technique and antibiotic sensitivity testing was carried out by employing the disc diffusion method. A total of fifty-eight (58) E. coli were obtained: SGH at 55 and POH at 3. Herein, in 100% of the total count, resistance was indicated for ampicillin and ertapenem, while 14%, 11%, 16% and 57% of the total count were resistant to ceftazidime, cefpodoxime, cefotaxime and amoxicillin-clavulanate, respectively. In addition, 94.8% showed resistance to tetracycline, 19% to ciprofloxacin, 6.9% to gentamycin, 39.7% to chloramphenicol and 55% and 47% to sulfamethoxazole-trimethoprim and nalidixic acid, respectively. Furthermore, 94.8% of all the isolates were multidrug resistant (MDR), while 29.3% were ESBL positive. Wastewater from the two hospitals under study contained ESBL positive and MDR E. coli, suggesting a need to forestall a potential threat to public health by treating the wastewater generated by both hospitals before discharge into the environment

Metal-resistance encoding gene-fingerprints in some bacteria isolated from wastewaters of selected printeries in Ibadan, South-western Nigeria

Several studies have reported the occurrence of metal-resistant bacteria and their genes in different wastewater, but there is a dearth of information on wastewater generated from printing operations as a probable source. This study aimed at fingerprinting metal-resistance encoding genes in bacteria recovered from wastewaters of selected printeries in Ibadan, Nigeria. Wastewaters from 10 selected printeries in Ibadan were collected monthly for 12 months. The metal composition of wastewater was determined using Atomic Absorption Spectrophotometry. Metal-resistant bacteria were isolated on metal-supplemented nutrient medium, and characterized using 16S rRNA gene sequencing. Metal-resistance genes were detected using specific primers and the presence of plasmids was determined using alkaline-lysis method. Forty metal-resistant bacteria belonging to six genera; Bacillus, Klebsiella, Pseudomonas, Citrobacter, Providencia and Proteus were identified. cusCBA, encoding resistance to copper and silver was detected in nine bacteria, while pbrA (encoding lead resistance) was detected in seven Pseudomonas aeruginosa isolates. chrA, encoding resistance to chromate ions, was detected in Proteus mirabilis PW3a and two isolates of Pseudomonas aeruginosa, while chrB was detected in Providencia vermicola PWAP3 and Proteus mirabilis PW4c. Bacillus stratosphericus PW1b possessed the copper-resistance genes, pcoA and pcoR. Thirty-six bacteria (90%) of the total bacteria possessed plasmids larger than 10 Kb in size. In conclusion, wastewater generated from printing operations could be a potential source of metal-resistant bacteria and their genes