Aims: Isolation and characterization of multiple antibiotic resistant Escherichia coli serotypes in cow raw milk and traditional dairy products in Osun state, Nigeria was reported. Study design: Raw milk of lactating cow, local cheese and yoghurts were sampled. Place and Duration of study: Samples were collected at different markets in Ile-Ife, Modakeke, Edun-abon, and Akinlalu in Osun State, Nigeria, between June and August, 2011. Methodology: Samples of cow raw milk, cheese and yoghurt were enumerated bacteriologically on MacConkey agar at 37 0 C for the total coliform. Isolation of E. coli was done on eosin methylene blue agar at 37 0 C using pour plate technique. The isolate identity was further confirmed by biochemical tests and serotyping. Antibiotic susceptibility of the isolates was determined by the disk diffusion technique. Molecular typing of Escherichia coli was performed using polymerase chain reaction (PCR) technique. Result: The coliform count ranged from 1.0 to 6.00×10 5 cfu/g in raw milk, 1.30 to 9.60×10 5 cfu/g in cheese and 1.3 to 5.0×10 5 cfu/g in yoghurt. The presence of E. coli was significantly low in cow raw milk compare to yoghurt and cheese (p< 0.05). Resistance to antibiotics varied among the E. coli isolates with the highest resistance to tetracycline (88.6 %), cotrimoxazole (77.2 %) and nitrofurantoin (6.81 %). Most E. coli isolates were multiple antibiotic resistant types displaying 17 different multiple antibiotic resistance patterns. All the Escherichia coli strains belonged to 9 serogroups ('O') and 17 serotypes ('H'). The 'O' serogroups identified include O26 (2), O55 (4), O86 (3), O111 (11), O114 (1), O119 (1), O127 (5), O128 (1) and O142 (4) with 0111 (35.48 %) being the most prevalent serotype. The flagellin (fliC) gene restriction analysis of Escherichia coli serotypes showed that 72.7% were motile with 17 H-type while 27.3% were non-motile and untypable, namely O55 (1), O86 (1), O111 (5), O119 (2), O127 (2), O142 (1). UNDER PEER REVIEW The polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) patterns for the amplified fliC gene in the Escherichia coli strains, produced bands of sizes ranging from 0.9 to 1.8 kb. Conclusion: The identification of E. coli O55:H27, O111:H8, O127:H42 and O142:H6 serotypes in the dairy products is of great public health concern.

Extended spectrum beta-lactamase (ESBL)-producing uropathogenic Escherichia coli (UPEC) in symptomatic pregnant women with confirmed urinary tract infections in Southwest. Nigeria was reported. Susceptibility of UPEC isolates to β-lactam and other classes of antibiotics was determined by the Kirby-Bauer's disc diffusion method on Mueller-Hinton agar plate. Detection of plasmid DNA in multiple antibiotic resistant isolates was carried out by alkali lysis (TENS) method. Extended-spectrum-β-lactamase (ESBL) production was determined by double disk synergy test (DDST). Isolates that were positive to ESBL were mated with non-ESBL-producing E. coli and other enterics in a conjugation experiment. Transfer of ESBL-enzyme and other resistance phenotypes in the transconjugants was investigated by DDST. Data obtained were statistically analyzed using SPSS 17. Greater percentage of the isolates were multiple antibiotic resistant (MAR). Sixty-nine (26.1 %) of UPEC were ESBL producers. Some of the ESBL producers transferred ESBL-enzyme and other resistance determinants to the recipients. Large size plasmid DNA of molecular weight (23.13-33.04 kb) was detected in some representative MAR isolates.

The study reports the characterization of uropathogenic E. coli (UPEC) in urine samples of pregnant women with confirmed urinary tract infections (UTIs) in Ondo and Ekiti States, Nigeria.Voided mid-stream urine samples were cultured on eosin methylene blue agar plates at 37 o C and identified by conventional biochemical tests. Antibiotic susceptibility testing of isolates was by Kirby-Bauer's disc diffusion technique. Phylogenetic typing of the isolates was by multiplex polymerase chain reaction (PCR).The occurrence of UPEC in pregnant women in age group 25-35 years (66.0%) was high. Two hundred and sixty four uropathogenic E. coli comprising 133 (50.38%) in Ondo and 131 (49.62%) in Ekiti States were recovered from 400 samlpes analyzed. In all, prevalence of UTIs with positive cultures was 66.0%. Escherichia coli only was 56.5%, mixed-infection (9.5%), non-E. coli infection (12.5%) and no growth (21.5%). Resistance to antibiotics was high with diverse multiple antibiotic resistance patterns. Greater percentage of the screened representative UPEC isolates belonged to phylogenetic group D (65.0%), group A (28.0%), group B1 (6.7%) and none to group B2.Escherichia coli belonging to phylogenetic group D appears to be a predominant uropathogen in this study area. Presence of chuA gene in most of the isolates shows the significance of iron acquisition in the pathogenesis and urovirulence of UPEC.

Extended spectrum beta-lactamases (ESBLs) are enzymes that are now becoming major sources of resistance to β-lactamase antibiotics more especially in enteric bacteria such as Klebsiella pneumoniae, P. aeruginosa and Escherichia coli. Increase in the frequency of the β-lactam resistance in bacteria has become a serious threat for treating bacterial infections caused by enterobacteriaceae. This study aims to determine the prevalence of ESBLs producers among enteric Gram negative bacteria isolated from patients in OAUTHC, Ile-Ife, Osun State. The subject used in this study involved patients presenting with evidence of hospital infections. The collected sputum specimens were processed for the isolation and identification of Gram negative bacilli. Resistance of the isolates to different antibiotics tested was determined using the standard disc diffusion method of Kirby-Bauer. Phenotypic and confirmatory test of the isolates were done for ESBL production using double disc synergy test (DDST) on Mueller Hinton agar according to CLSI 2013 guidelines. Results reveal that the highest occurrence of bacteria was recovered in Klebsiella species (35%), followed by Enterobacter sp. (13%), P. aeruginosa (10%), Escherichia coli and Salmonella sp. (7%) while the least occurs in Proteus sp. All the isolates were 100% resistance to class piperacillin, 76.6% to beta-lactamase inhibitor and 52% resistance to cephalosporins while they were susceptible to carbapenems, nitrofurans, and fluoroquinolones. The prevalence of ESBLs producing isolates was 51.1% while non-ESBL producing strains were 48.8%. Therefore, it can be concluded that extended spectrum beta lactamases are gradually increasing in Nigeria with co-resistance to some other classes of antibiotics which is very alarming. There is a limited number of drugs sensitivity for these bacteria and the drug of choice is imipenem, ciprofloxacin and ofloxacin.

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