Background Bacterial resistance to commonly-used antibiotics has been on the increase especially in the clinical settings. This study focused on the detection of plasmid-mediated quinolone resistance (PMQR) determinants in ciprofloxacin-resistant bacteria recovered from Urinary Tract Infection (UTI) samples. Results Already characterized isolates from urine samples of UTI-diagnosed in- and out- patients were obtained from the culture pool of the Department of Medical Microbiology and Parasitology, University College Hospital (UCH), Ibadan, Nigeria. A total of seventy-three ciprofloxacin-resistant isolates were used in this study. Of the 73 UTI isolates, 43 carried at least one of the four PMQR genes targeted and they belonged to eight bacterial genera namely: Escherichia (25), Klebsiella (10), Pseudomonas (2), Proteus (2) and one isolate each belonging to Enterobacter, Acinetobacter, Citrobacter and Salmonella genera. qnrA was detected in 10.9% (8/73) of the isolates while the occurrence of qnrB and qnrS was 32.9% (24/73) and 20.5% (15/73), respectively. The quinolone efflux pump (qepA) was detected in 9/73 (12.3%) of the isolates. Thirty of the isolates carried only one PMQR gene, while thirteen carried two PMQR genes. There was no carriage of more than two PMQR genes in the forty-three isolates from which PMQR genes were detected. Conclusion This study reports the carriage of PMQR determinants by eight of the nine Gram-negative bacterial genera from urinary sources in patients attending the University College Hospital, Ibadan over the four-month period of study. This is quite worrisome as it suggests a high contribution of UTI cases to the burden of quinolone resistance. There is a need for more studies of this nature in other hospitals in Nigeria, to develop a database on the contribution of UTI cases to quinolone resistance.

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Infections of the urinary tract have been on the rise globally and these are also worsened by the increasing rate of antibiotic resistance in uropathogens. This study aimed to determine the susceptibility profile of extended spectrum β-lactamase (ESBL)- producing uropathogens to selected antibiotics and their carriage of ESBL genes. Bacterial uropathogens were obtained from the urine bench of a Microbiology laboratory in a Teaching Hospital in South-West Nigeria. Susceptibility to antibiotics was tested using the disc diffusion method, while detection of ESBL production was done using the double disc synergy test (DDST). Detection of ESBL genes was performed by PCR. A total of 21 ESBL- producing uropathogens were obtained namely: Klebsiella pneumoniae (11), Klebsiella oxytoca (6), Proteus mirabilis (2), Enterobacter cloacae (1) and Pseudomonas aeruginosa (1). The resistance to antibiotics in the uropathogens was: imipenem (0%), gentamicin (38.1%), sulfamethoxazole-trimethoprim (52.4%), amoxicillin-clavulanate (61.9%), aztreonam (66.7%), ceftazidime (66.7%), tetracycline (90.5%), cefpodoxime (100%) and cefotaxime (100%). Altogether, 90.5% (19/21) of the isolates were multidrug resistant (MDR). Of the 21 uropathogens, 61.9% (13/21) carried bla CTX-M, 52.4% (11/21) carried bla TEM while bla SHV was detected in 47.6% (10/21) of the isolates. There was co-carriage of ESBL genes in 12 uropathogens. This study showed a high prevalence of multidrug resistance and a high carriage of ESBL genes in the ESBL- producing isolates obtained over the study period. There is a need for a review of antibiotic options in the treatment of UTI to clamp down on the ever-increasing tide of antibiotic resistance in uropathogens.

Background The use of metal-containing and antimicrobial compounds is a common practice in aquaculture operations in Nigeria. Only a few studies have focused on the impact of these chemicals on metal and antibiotic resistance development in the bacterial flora of aquaculture. This study therefore sets out to fill this gap. Results Five metals, namely copper (Cu), zinc (Zn), lead (Pb), nickel (Ni) and chromium (Cr), were detected at different concentrations in the pond water samples, with most values obtained exceeding the maximum recommended national standard for fisheries and recreation water quality criteria set by the National Environmental Standards and Regulations Enforcement Agency (NESREA) in Nigeria. A total of 121 Vibrio spp. were recovered from the aquaculture pond water with Vibrio cholerae having the highest frequency (37) followed by Vibrio parahaemolyticus (36), Vibrio vulnificus (36) and Vibrio alginolyticus (12). Seventy-five isolates were recovered from ponds with history of antibiotic use, while the ponds with no recognized history of antibiotic use had forty-six isolates. The percentage resistance to antibiotics in the isolates was: ampicillin (88.5%), amoxicillin–clavulanate (44.3%), tetracycline (41%), trimethoprim-sulfamethoxazole (22.1%), chloramphenicol (15.6%), ciprofloxacin (11.5%), imipenem (5.7%), ceftazidime (4.1%) and gentamicin (0%). All the isolates tolerated all the metals to 400 µg/mL concentration while only the trio of Pb, Ni and Cr were tolerated beyond the concentration. Zn and Cu appeared to be the most toxic metals on Vibrio spp., with no isolate surviving beyond the 400 µg/mL concentration mark, while 57 of the 121 isolates survived Cr at the highest concentration (3200 µg/mL), making it the most tolerated of the metals. Conclusion This study reports a high level of metal contamination in the aquaculture ponds studied. The concentration of the metals exceeded the maximum permissible limits in Nigeria. Also, there was coexistence of metal and antibiotic resistance in the bacteria recovered from the aquaculture ponds. There is a need to regulate the use of chemicals, especially antibiotics and some biocidal compounds, to clamp down on the introduction of metals and antibiotics into the aquaculture systems, as these chemicals could facilitate the development of resistance traits in aquaculture bacteria by creating a selective pressure in the aquaculture environment.

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There have been a rapid rise in the consumption of quinolones in human and veterinary medicine recently. This has contributed in no small measure to the rising incidence of quinolone resistance in bacteria. This study investigated the antibiotic resistance and carriage of plasmid-mediated quinolone resistance (PMQR) determinants by ESBL-producing E. coli obtained from the animal waste dumps of an agricultural farm. Isolation of ESBL-producing E. coli from the animal waste samples was done on CHROMagar ESBL, while presumptive isolates were picked and identified using molecular method (detection of uidA gene). Susceptibility to a panel of ten antibiotics was done using disc diffusion method, and detection of PMQR genes (qnrA, qnrB, qnrS, aac(6')-lb-cr, qepA and oqxAB) was done using primer-specific PCR. A total of twenty-five ESBL-producing E. coli was obtained from the cattle (6), piggery (7) and poultry (12) waste dumps of the farm. There was 100% resistance by the isolates to cefpodoxime, cefotaxime, enrofloxacin, trimethoprim-sulfamethoxazole and penicillin, while no resistance was observed to amoxicillin-clavulanate and imipenem. The resistance by the isolates to ceftazidime and streptomycin was 24% and 48% respectively. The frequency of detection of PMQR genes in the isolates was: qnrA (96%), qnrB (88%), qnrS (88%), aac(6')-lb-cr (80%), qepA (80%) and oqxAB (96%). This findings showed a high level of antibiotic resistance and PMQR genes in the ESBL-producing E. coli in this study; suggesting that animal waste dumps in agricultural farms could be a budding ‘hotspot’ for antibiotic resistant bacteria and resistance genes.