Antibiotic resistance and resistance genes in Escherichia coli from poultry farms, southwest Nigeria

Introduction: This study investigated the mechanisms of resistance in 36 E. coli isolated from waste, litter, soil and water samples collected from poultry farms in Southwestern Nigeria. Methodology: Minimum inhibitory concentration (MIC) distributions of the isolates were determined using the methods of the Clinical and Laboratory Standard Institute and resistance genes detected by PCR. Results: A total of 30 isolates (94%) showed resistance to more than one antimicrobial. Percentage resistance was: tetracycline 81%, sulphamethoxazole 67%, streptomycin 56%, trimethoprim 47 %, ciprofloxacin 42%, ampicillin 36%, spectinomycin 28%, nalidixic acid 25%, chloramphenicol 22%, neomycin 14%, gentamicin 8%, amoxicillin-clavulanate, ceftiofur, cefotaxime, colistin, florfenicol and apramycin 0%. Resistance genes found among the isolates include bla-TEM (85%), sul2 (67%), sul3 (17%), aadA (65%), strA (70%), strB (61%), catA1 (25%), cmlA1 (13%), tetA (21%) and tetB (17%). Class 1 and 2 integrons were found in five (14%) and six (17%) isolates, respectively, while one isolate was positive for both classes of integrons. Seven out of eight isolates with resistance to ciprofloxacin and MIC ≤ 32 mg/L to nalidixic acid contained qnrS genes. Conclusions: Our findings provided additional evidence that the poultry production environment in Nigeria represents an important reservoir of antibiotic resistance genes such as qnrS that may spread from livestock production farms to human populations via manure and water.</jats:p

Bioaugmentation Approach using Pseudomonas and Bacillus for Malodour Reduction in Poultry Feacal Waste Management

Introduction. A workable strategy is bioaugmentation, which involves introducing certain bacteria in sufficient quantities to promote biodegradation. This study focuses on isolating and utilizing malodor-reducing bacteria from fecal wastes obtained from a poultry farm in Ashi, Ibadan. Methods. Standard methods were employed to isolate and identify species of Pseudomonas and Bacillus. Quantitative detection of hydrogen sulfide gas and other relevant parameters was performed using MSA Orion and Multi Gas Detector. Hydrogen sulfide (H2S) release was quantitatively monitored during fermentation, considering varying loads of inocula. Results. The bacterial isolates comprised Pseudomonas aeruginosa, P. fluorescens, P. putida, Bacillus fastidiosus, B. licheniformis, B. megaterium, B. subtilis, B. sphaericus, and B. thuringiensis. Odor levels varied based on inocula load and fermentation duration. In batches with Pseudomonas, hydrogen sulfide was undetectable after two days, while Bacillus-inoculated batches required ten days. The formation of microbial mats and subsequent decrease in H2S content contributed to malodor reduction. Notably, fluorescent pseudomonas exhibited successful mineralization during the treatment of fecal waste. Conclusion. Pseudomonas isolates demonstrated superior effectiveness in odor reduction compared to Bacillus isolates

Evaluation of Resistance Pattern and Plasmid Profile of Staphylococcus Species Isolated from Clinical and Community Samples in Ibadan South-West, Nigeria

Aims: Staphylococcus species have been a major human pathogen of public health importance globally. This study was designed to evaluate the resistance pattern and plasmid profile of Staphylococcus species isolated from clinical and community settings. Methodology: Staphylococcus species from clinical (55) and community (53) which were previously isolated in University of Ibadan and her teaching hospital and identified as S. epidermidis (92.6%), S. aureus (6.5%) and S. xylosus (0.9%) were used. The antibiogram and plasmid profiles were determined by standard procedures. Results: In clinical isolates of S. epidermidis, 30.9, 34.5, 40.0, 41.8, 60.0, 76.4, and 89.1% were resistant to chloramphenicol (CHL), streptomycin (STR), erythromycin (ERY), gentamycin (GEN), tetracycline (TET), cotrimoxazole (COT), and cloxacillin (CXC) respectively. Correspondingly, in community isolates of S. epidermidis, 28.3, 32.1, 50.9, 26.4, 58.5, 90.6 and 92.5% were resistant to these antibiotics. The only clinical S. xylosus isolated was resistant to all the antibiotics except CHL and STR. In the clinical isolates of S. aureus, 5.5, 5.5, 7.3, 7.3, 7.3, 9.1 and 9.1% were resistant to ERY, CHL, STR, GEN, TET, COT and CXC respectively. In community isolates, only one S. aureus was resistant to COT, CHL, ERY, GEN and STR while two were resistant to CXC. Plasmid profiling showed that 33/35 (94.3%) of clinical and 17/19 (89.5%) of community isolates had plasmid of size 23.13 kb. Conclusion: The increasing resistance and similarity of plasmid profile of the community isolates to clinical isolates call for urgent establishment of antibiotic surveillance system to minimize the emergence of drug resistance pathogens in the community

Characterization of biosurfactant-producing bacterial strains isolated from agro-industrial wastes in southwestern, Nigeria

Introduction. The difficulty of managing trash and cleaning up the environment prompted interest in biosurfactants and surface-active proteins made by microbes. The study aims to augment bacterial isolates from agro-industrial wastes targeted for possible mass production of biosurfactants. Methods. Six agro-industrial wastes from Cassava, Palm kernel, and Sawdust from six agro-industrial sites within Ijebu area in Ogun State were collected for standard laboratory analyses in the Biotechnology Unit of the Federal Industrial Institute for Research, Oshodi (FIIRO). Five screening methods; blood hemolysis, lipase activity, blue agar hydrolysis, oil spreading, and emulsification index (EI24) were carried out to confirm biosurfactant production. Isolates with the highest hyper-production were subjected to 16rRNA molecular identification. Results. The study justified efficient biosurfactant production from 4 bacterial isolates out of 26 screened bacterial isolates from hydrocarbon degraders and 29 heterotrophic screened bacterial isolates, making a total of 55 screened bacterial isolates. Screening results reveal the emulsification capacities of identified Pseudomonas putida strain SG1, Acinetobacter baumanii strain MS14413, Bacillus zhangzhouensis strain cdsV18, and Burkholderia cepacia strain 717. Conclusion. Biosurfactant bacteria produced in all agricultural and industrial wastes considered in this study are capable of mass production.

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