Extended Spectrum Beta-Lactamases (ESBLs) encoding genes (TEM, SHV and OXA) were amplified from multidrug resistance E. coli. The multidrug resistance E. coli isolates from different clinical sources were documented to be plasmid encoded and resistance against β-lactam and cephalosporin. Conventional laboratory analysis showed that seventy percent (70%) of the selected multidrug resistant clinical isolates were ESBLs positive, showing a ≥5 mm increase in zone diameter for either antibiotics compared to its zone when tested alone. The antibiotic susceptibility result showed that 100% of the isolates were resistant to amoxicillin-clavulanic acid, amoxicillin, cefuroxime and ampicillin-sulbactam while 90% of the isolates were resistant to ceftazidine and tetracycline, 80% to ofloxacin, 70% to ceftriazon, nalidixic acid, cefalexin, 60% to ciprofloxacin, 50% to nitrofurantoin, 40% to chloramphenicol and 20% to gentamicine. The multiplex PCR with primers TEM (931bp), SHV (868), OXA-2 (478), aac(3)-IIa (900) and rmtA (634), which are genes responsible for extended spectrum β-lactamase and aminoglycoside resistance in E. coli shows that: isolate W15 comprises of three (3) resistant gene, which corresponds with TEM resolving as a 931 base pair, SHV 868 base pair, and a 478 bp indicating OXA-2 that is faint probably indicating a low concentration of the gene. Isolate B2 comprises single resistant gene, which is interpreted as OXA-2 with 478 base pair while isolate URO2, U64 and S45 comprises of two resistance genes which resolve as 868 and 478 base pair indicating SHV and OXA-2 respectively. However, isolates S57, U58 and B7 showed no gene amplification despite the various degree of resistance in MIC and * Corresponding author. J. C. Igwe et al. 277antibiotic susceptibility profile test obtained with conventional detection analysis. We assume that their resistant genes are not coded for by the primers used in this study as these isolates are likely to contain other resistant genes, which are also expressed at a molecular level. This study stands to show that molecular characterization has a great correlation with analytical methods.

Escherichia coli (E. coli) has been identified as the most common uropathogenic bacterial pathogen with increasing resistance to antibiotics. Aetiology of urinary tract infections (UTI) and their antibiotic sensitivity patterns vary from time to time and across different areas. In Nigeria, studies on the prevalence and antimicrobial susceptibility patterns of clinical isolates from urinary tract infections are inadequate. Employing standardised microbiological methods, this study assessed the prevalence and antimicrobial susceptibility patterns of E. coli isolates from UTI in University of Maiduguri Teaching Hospital (a tertiary health care institution) in North Eastern, Nigeria. Uropathogenic E. coli (UPEC) accounted for 150 (62.50%) of 240 urine isolates. Lowest susceptibility was for Ampicillin 54 (36.0%), Ciprofloxacin 69 (46.0%) and Norfloxacin 72 (48.0%). More than 50% were susceptible to Levofloxacin and Streptomycin 71 (54.0%) each, Cefuroxime and Co-trimoxazole 78 (52.0%) each, while highest susceptibility was for Nitrofurantoin 117 (78.0%), Chloramphenicol 105 (70.0%) and Gentamicin 96 (64.0%). The isolates were commonly resistant to 9 (24.24%) of the ten (MARI of 0.9) classes of antimicrobial agents used in this study and all the isolates were multidrug-resistant. There is a need for proper surveillance and development of hospital specific antibiograms to inform appropriate empiric therapy of urinary tract infections.

This study evaluated biofilm formation and antibiotic susceptibility in 36 clinical S. aureus isolates recovered from orthopaedic patients and detected the presence of intercellular adhesion and adhesin genes. Staphylococcus aureus was isolated from nasal swab, wound and urine specimens collected from orthopaedic patients in National Orthopaedic Hospital Dala, Kano over a period of three months. The isolates were identified using rapid identification kit for Staphylococcus species. The antibiotics susceptibility of the isolates was determined using modified disc diffusion method. Phenotypically, the biofilm formation was assessed using the Congo red agar method and microtitre plate assay. Polymerase chain reaction (PCR) analysis was used to detect biofilm-associated genes and characterize the isolates. The isolation rate of S. aureus from the samples (n = 134) was 26.8%, mainly from nasal swab (36%) and wound swab (36%). A total of 19 (52.7%) of the isolates showed positive for slime production. Majority of the isolates 29/36 (81.6%) were biofilm positive with only 2 (5.5%) and 5 (13.8%) as strong biofilm-formers and moderate biofilm-formers respectively. Molecular evaluation of the biofilm-associated genes in 12 S. aureus isolates revealed the prevalence of bbp genes (25%), clfA genes (16.6%) and the icaA (8.3%). None of the isolates harboured the fnbA and cna genes. There is no significant difference (P > 0.05) in the antibiotic resistance pattern between biofilm-positive and biofilm-negative S. aureus isolates. This result revealed that phenotypically most of the S. aureus isolates were biofilm formers but few of them chromosomally harbour the biofilm-associated genes.

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