We studied the presence of extended spectrum beta lactamases (ESBLs) in 44 clinical isolates of Escherichia coli collected from out-patients in two university teaching hospitals in South-Eastern Nigeria. Species identification was performed by standard microbiology methods and re-confirmed by MALDI-TOF technology. Phenotypic characterization of ESBL enzymes was done by double disc synergy test and presence of ESBL genes was determined by specific PCR followed by sequencing. Transfer of plasmid DNA was carried out by transformation using E. coli DH5 as recipient strain. Phenotypic characterization identified all isolates to be ESBL positive. 77% of strains were from urine, 13.6% from vaginal swabs and 9.0% from wound swabs. 63.6% were from female patients, 68% were from outpatients and 95.5% from patients younger than 30 years. All ESBL producers were positive in a PCR for blaCTX-M-1 cluster, in exemplary strains blaCTX-M-15 was found by sequencing. In all strains ISEcp1 was found upstream and ORF477 downstream of blaCTX-M. PCR for blaTEM and blaOXA-1 was positive in 93.1% of strains, whereas blaSHV was not detected, aac(6′)-Ib-cr was found in 97.7% of strains. RAPD analysis revealed seven different clonal groups named A through G with the majority of the strains (65.9%) belonging to clone A. Transfer of an ESBL plasmid with co-resistance to gentamicin, kanamycin, tobramycin, doxycycline and trimethropim-sulfamethoxazole was successful in 19 (43.2%) strains. This study showed a high rate of CTX-M-1 cluster - ESBLs in South-Eastern Nigeria and further confirms the worldwide spread of CTX-M ESBL in clinical isolates.

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Little is known about the molecular basis of antibiotic resistance among uropathogens in Southeast Nigeria. The aim of the study was to characterize enterobacterial uropathogens with respect to drug resistance. One hundred (100) enterobacterial uropathogens were studied. Their antibiotic susceptibility patterns were evaluated using disk diffusion, screened, and confirmed phenotypically for the presence of β-lactamases: ESBL, AmpC, carbapenemase, and MBLs. Screen positives were further tested for various β-lactamase genes by PCR. Our isolates showed variable resistance to most drugs tested. Out of the 58 ESBL screen positive E. coli, 35 were confirmed positive with PCR. The predominant ESBL gene was blaTEM while blaSPM was the most prevalent among MBL genes. Forty-six percentage of the screen positive Salmonella isolates coharbored blaTEM + SHV genes. Nine of the 10 ESBL screen positive K. pneumoniae were phenotypically and PCR positive. Three isolates of K. pneumoniae were positive for MBL genes. All the 10 C. freundii were positive for ESBL genes. The study showed high prevalence of drug-resistant genes among the enterobacterial uropathogens. Majority of the uropathogens harbored >1 antibiotic-resistant gene, and the most predominant gene was ESBL (blaTEM) followed by the MBL (SPM) gene.

Opportunistic infections including urinary tract infections (UTIs) are among the predominant cause of morbidity and mortality among HIV infected patients. Persons living with HIV/AIDS (PLWHA) are prone to infection from non-pathogenic microbes in the environment than normal individuals; and this development has been greatly attributed to the weakened immune system of HIV infected patients which makes it difficult to protect the body against invading commensal organisms. In this study, midstream urine (MSU) samples from HIV infected patients who attended the Federal Teaching Hospital Abakaliki (FETHA), Ebonyi State, Nigeria for routine antiretroviral therapy were evaluated by microbiological analysis for uropathogens. Antibiogram was also investigated on all isolated uropathogens by the Kirby-Bauer disk diffusion method. The uropathogens isolated from the MSU of HIV infected patients in this study were identified as: Escherichia coli, Staphylococcus aureus, Klebsiella pneumoniae and Proteus mirabilis. S. aureus was the most prevalent isolated organism (n=34). This was followed by K. pneumoniae (n=17), E. coli (16) and P. mirabilis (n=8). All uropathogens produced varying rates of susceptibility and resistance patterns to the tested antibiotics. High sensitivity was observed with gentamicin, ciprofloxacin, ampicillin and amoxycillin-clavulanic acid. Cefotaxime, ceftazidime, cefazolin, ceftriaxone, cefepime, and cefoxitin (which are all 3 rd-generation β-lactams) showed less efficacy against the uropathogens. This study draws attention to the increasing rate of UTIs amongst HIV infected patients in Abakaliki metropolis, Ebonyi State of Nigeria, and the resistance of uropathogens to some available antibiotics. Therefore, there is need to checkmate the menace through proper detection and treatment of affected individuals in order to improve the health status of PLWHA in this environment.

Background Gram-negative bacteria (GNB) including Escherichia coli, Pseudomonas aeruginosa, and Klebsiella pneumoniae represent the most relevant reservoir of resistance genes such as metallo-β-lactamase (MBL) and AmpC genes that give them the undue advantage to resist antimicrobial onslaught. This study aimed to investigate the occurrence of MBL (blaIMP-1, blaIMP-2, blaVIM-1, blaVIM-2) and AmpC (blaFOX, blaDHA, blaCMY, blaACC) resistance genes in aforementioned GNB collected from abattoir and poultry sources in Nigeria. Results In total, 370 isolates were collected from abattoir tables (n = 130), anal region of cows (n = 120), and the cloacae of poultry birds (n = 120). The test isolates showed high rate of resistance to cephalosporins and carbapenems. The MBLs were phenotypically detected in 22 E. coli, 22 P. aeruginosa, and 18 K. pneumoniae isolates using combined disc test (CDT). However, only 11 E. coli, 24 P. aeruginosa, and 18 Klebsiella pneumoniae isolates were phenotypically confirmed to be AmpC producers using cefoxitin-cloxacillin double disk synergy test (CC-DDST). MBL encoding genes (particularly the blaIMP-1 genes and blaIMP-2 genes) were detected by polymerase chain reaction (PCR) in 12 (54.6%) E. coli, 15 (83.3%) K. pneumoniae, and 16 (72.7%) P. aeruginosa isolates. AmpC genes (particularly the blaCMY genes and blaFOX genes) were found in a total of 5 (29.4%) E. coli isolates, 5 (27.8%) isolates of K. pneumoniae, and 10 (41.7%) isolates of P. aeruginosa. Conclusions Our study showed the circulation of MBL and AmpC genes in GNB from abattoir and poultry origin in Nigeria. Adoption of regular control policies is necessary to reduce the spread of these species as soon as possible, especially in poultry and slaughterhouses.

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The non-hospital environment particularly poultry farms and abattoirs are fast becoming reservoir channels for the transmission of antibiotic resistant bacteria including those that produce metallo beta-lactamases (MBLs). Foodproducing animal's habouring multidrug resistant bacteria including those that produce metallo-beta-lactamases (MBLs) poses health risks to the human population. This study investigated the prevalence of bla IMP-1 and bla VIM-1 MBL genes in Pseudomonas aeruginosa isolates from food-producing animals by multiplex PCR technique. Anal swab samples (n=120) were bacteriologically analyzed on cetrimide selective agar for the selective isolation of P. aeruginosa isolates. Antibiogram was carried out as per the Clinical and Laboratory Standard Institute (CLSI) criteria. The production of MBLs was detected phenotypically and genotypically using the modified Hodges test method and multiplex PCR technique respectively. DNA products were run on 1.5 % agarose gel, and visualized using a UV transilluminator at 260 nm. Data was analyzed statistically using SPSS version 23.0. Out of the 120 anal swab samples, a total of 43 (35.8 %) isolates of P. aeruginosa was bacteriologically recovered. The P. aeruginosa isolates were found to be resistant to ampicillin (88.4 %), cefotaxime (81.4 %), gentamicin (79.1 %), sulphamethoxazole-trimethoprim (72.1 %), oxacillin (76.7 %), nitrofurantoin (76.7 %), meropenem (62.8 %), ofloxacin (67.4 %), imipenem (65.1 %) and cloxacillin (69.8 %). MBL was phenotypically detected in 15 (34.9 %) isolates of P. aeruginosa. However, the multiplex PCR technique significantly confirmed MBL production in only 12 (27.9) isolates of P. aeruginosa (p<0.001) that harboured the bla IMP-1 MBL genes. The bla VIM-1 MBL genes were not detected in the MBL positive P. aeruginosa phenotypes. The P. aeruginosa isolates that harboured the bla IMP-1 MBL genes were found to be multiply resistant. This study reported for the first time the prevalence of bla IMP-1 MBL genes from P. aeruginosa isolates from anal swab samples of food-producing animals in Abakaliki, Nigeria. The long-term exposure of food-producing animals to antibiotics could cause accumulation of antibiotic resistance determinants in the gut microbiota of these animals.