Genotypic Characterization of Aminoglycoside Resistance Genes from Bacteria Isolates in Selected Municipal Drinking Water Distribution Sources in Southwestern Nigeria

BACKGROUND: Multi-drug Resistant (MDR) bacteria could lead to treatment failure of infectious diseases and could be transferred by non-potable water. Few studies have investigated occurrence of Antibiotic Resistance Genes (ARGs) among bacteria including Aminoglycoside Modifying Genes (AMGs) from Drinking Water Distribution Systems (DWDS) in Nigeria. Here, we aimed at characterization of AMGs from DWDS from selected states insouthwestern Nigeria.METHODS: One hundred and eighty one (181) MDR bacteria that had been previously characterized using 16S rDNA and showed resistance to at least one aminoglycoside antibiotic were selected from treated and untreated six water distribution systems in southwestern Nigeria. MDR bacteria were PCR genotyped for three AMGs:aph (3´´)c, ant (3´´)b and aph(6)-1dd.RESULTS: Out of 181 MDR bacteria genotyped, 69(38.12%) tested positive for at least one of the genotyped AMGs. Highest (50, 27.62%) detected gene was ant (3”)c followed by aph (3")c(33,18.23%). Combination of aph(3")c and ant (3")b in a single bacteria was observed as the highest (14, 7.73%) among the detected gene combination. Alcaligenes sp showed the highest (10/20) occurrence of ant (3")b while aph(3")c was the highest detected among Proteussp (11/22). Other bacteria that showed the presence of AMGs include: Acinetobacter, Aeromonas, Bordetella, Brevundimonas, Chromobacterium, Klebsiella, Leucobacter, Morganella, Pantoae, Proteus, Providencia, Psychrobacter and Serratia.CONCLUSIONS: High occurrence of ant (3”)c and aph (3”)c among these bacteria call for urgent attention among public health workers, because these genes can be easily disseminated to consumers of these water samples if present on mobile genetic elements like plasmids, integrons and transposons

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

Comparative Study of Antibacterial Activities of Ethanol Extracts of the Bark and Seeds of Garcinia kola and Caricapapaya

A comparative study of the antimicrobial activities of the bark and seed extracts of Garcinia kola and Carica papaya were tested using the Agar well diffusion method on eight bacterial strains - Staphylococcus aureus ; Salmonella typhi B ; Shigelladysenteria ; Pseudomonas aeruginosa ; Serratiamarcescens ; Pseudomonas fluorescens ; Proteus vulgaris ; and Bacillus subtillis . Phytochemical screening shows that both bark and seed of the two plants contain reducing sugars, phenols and alkaloids whereas the pawpaw extracts contained tannins which were absent in the bitter kola plant part. Garcinakola on the other hand has saponin that was not present in Caricapapaya. The Garcinia seed ethanol extract manifested the best inhibitory activities against the test bacteria, producing inhibition zones ranging from 12–23mm. There was no resistance from any of the test bacteria. The pawpaw seed extract was also effective against the test bacteria. The inhibition zone observed ranged from 11-16mm. The ethanol extract of both plants were active against Staphylococcus aureus, Shigelladysenteria, Pseudomonas fluorescens; and Salmonella typhi B. Pawpaw leaf ethanolic extract significantly inhibited Pseudomiasaeruginosa, while Garcinia seeds ethanolic extract also inhibited Bacillus substilis. The activity index of ethanol extract of Garcinia kola seed was higher than that of pawpaw seed when both gentamicin and tetracycline were used as a standard antibiotics. The aqueous extract of both plant parts were not as effective as the ethanol extract. The activities of these medicinal plants against the tested bacterial species in this study justified their common use in African traditional medicine in the treatment of various ailments

Detection of Extended Spectrum Beta-Lactamases Resistance Genes among Bacteria Isolated from Selected Drinking Water Distribution Channels in Southwestern Nigeria

Extended Spectrum Beta-Lactamases (ESBL) provide high level resistance to beta-lactam antibiotics among bacteria. In this study, previously described multidrug resistant bacteria from raw, treated, and municipal taps of DWDS from selected dams in southwestern Nigeria were assessed for the presence of ESBL resistance genes which include blaTEM, blaSHV, and blaCTX by PCR amplification. A total of 164 bacteria spread across treated (33), raw (66), and municipal taps (68), belonging to α-Proteobacteria, β-Proteobacteria, γ-Proteobacteria, Flavobacteriia, Bacilli, and Actinobacteria group, were selected for this study. Among these bacteria, the most commonly observed resistance was for ampicillin and amoxicillin/clavulanic acid (61 isolates). Sixty-one isolates carried at least one of the targeted ESBL genes with blaTEM being the most abundant (50/61) and blaCTX being detected least (3/61). Klebsiella was the most frequently identified genus (18.03%) to harbour ESBL gene followed by Proteus (14.75%). Moreover, combinations of two ESBL genes, blaSHV+blaTEM or blaCTX+blaTEM, were observed in 11 and 1 isolate, respectively. In conclusion, classic blaTEM ESBL gene was present in multiple bacterial strains that were isolated from DWDS sources in Nigeria. These environments may serve as foci exchange of genetic traits in a diversity of Gram-negative bacteria

Characterisation of a novel manganese-containing exopolysaccharide produced from Pseudomonas aeruginosa strain S16 isolated from soil in a mixed animal farm at Ibadan, Oyo State, Nigeria

Antibiotic resistance, that occurs globally, has led to a reduction in the efficacy of many contemporary conventional antibiotics. The aim of this study was to characterise an exopolysaccharide, produced from Pseudomonas aeruginosa strain S16, accession number OQ734845, observed to be effective against, an identified strain of Klebsiella pneumoniae, at 0.156 g/L, and against Staphylococcus aureus SO183, at 0.260 g/L. Pseudomonas aeruginosa strain S16, was previously isolated from soil, in a mixed animal farm, at Ajibode area, Oyo state, Ibadan, Nigeria, through the pour plate method, before it was identified, through biochemical tests, and molecular studies. High performance liquid chromatography (HPLC), and mass spectrometry (MS), of the exopolysaccharide, revealed monosaccharide moieties of glucose, rhamnose, xylose arabinose, D-ribose, galactose, mannose and inositol and each possessed varying peaks. The phenol-sulfuric acid method, quantified the carbohydrate sugars concentration, as 0.0060 g/L. Scanning electron microscopy (SEM), revealed a sparsely flaky, exopolysaccharide surface, with globular projections. Energy dispersive x-ray spectroscopy (EDX), revealed nitrogen (48.00%), carbon (20.10%), phosphorus (12.60%), sodium (8.00%) and oxygen (6.00%), were the predominant elements in the exopolysaccharide, while manganese (0.33%), was the least predominant. Fourier transform infrared (FTIR) spectroscopy, revealed the presence of carboxyl, imine or oxime, nitro, halo, and anhydride functional groups. The exopolysaccharide, was a modified exopolysaccharide; specifically, a manganese-containing, phosphorylated, nitrogenous, heteropolysaccharide. The manganese, likely conferred on the exopolysaccharide, the potential for a range of biological activities. From available documented research, this is the first time, a manganese-containing exopolysaccharide has been reported