Prevalence of extended spectrum beta lactamase and plasmid mediated quinolone resistant genes in strains of Klebsiella pneumonia, Morganella morganii, Leclercia adecarboxylata and Citrobacter freundii isolated from poultry in South Western Nigeria

Abstract

A serious concern is arising on the coexistence of extended-spectrum beta-lactamase (ESBL) and plasmid mediated quinolone resistance (PMQR) producing bacteria in animal husbandry, which could be transferred to humans, especially in strains that may not be routinely screened for resistance. This study therefore tested the prevalence of ESBL and PMQR genes in selected bacteria isolated from poultry faeces. Faecal droppings of birds were collected from 11 farms in five states in South Western Nigeria. Bacteria were isolated from the samples on cefotaxime supplemented plates and identified with MALDI-TOF. The MIC was determined using VITEK system and resistance genes were detected with PCR. A total of 350 strains were isolated from different samples and selected strains were identified as 23 Klebsiella pneumonia, 12 Morganella morganii, seven Leclercia adecarboxylata and one Citrobacter freundii. All the species were resistant to gentamycin, trimethoprim/sulphamethaxole, tobramycin, piperacillin, cefotaxime and aztreonam (except Morganella morganii strains which were mostly susceptible to aztreonam). All the tested strains were susceptible to imipenem, meropenem and amikacin. All Leclercia adecarboxylata strains were resistant to ceftazidime, cefepime and fosfomycin while all Morganella morganii strains were resistant to fosfomycin, moxifloxacin and ciprofloxacin. All tested species were generally sensitive to ciprofloxacin except Morganella morganii strains which were resistant to ciprofloxacin. The resistance to ciprofloxacin, ceftazidime, cefepime, tigercylin, colistin and fosfomycin were 65%, 40%, 23%,, 7%, 33%, 48% respectively while the prevalence of SHV, TEM and CTX genes were 42%, 63%, 35% respectively. 9.3% of the isolates had the three ESBL genes, 2.33% had qnrA gene, 4.65% had qnr B gene while none had qnrS gene. The most prevalent PMQR gene is Oqxb (25.58%) while 6.98% had the qep gene. Klebsiella pneumoniae generally had both ESBL and PMQR genes. The high prevalence of extended spectrum beta-lactamase genes in the studied strains calls for caution in the use of beta lactam antibiotics in poultry feeds. This is the first report of the occurrence of extended spectrum beta-lactamase and plasmid mediated quinolone resistance genes in Morganella morganii and Leclercia adecarboxylata strains isolated from poultry faeces.