In this study, copper nanoparticle (CuNPs) was synthesized using green technology and the CuNPs was characterized with Energy Dispersive X-ray (EDX) which confirmed the presence of copper. Scanning Electron Microscopy (SEM) showed the morphology and the average size was calculated to be 2.47 ± 1 nm. The functional groups were identified by Fourier transform infrared spectroscopy (FTIR) and this revealed that OH functional group was anchored on the surface of the nanoparticles. Antimicrobial activity of the synthesizedCuNPs was investigated at varying concentrations (0.25, 0.5, 1, 2, 3, 4, 5, 6 and 7 mg/ml) dissolved in 100% dimethyl sulfoxide (DMSO). It was tested against five food borne pathogenic organisms: Salmonella typhimurium, Methicillin resistant Staphylococcus aureus  (MRSA), Enterococcus faecalis, Shigella flexneri, and Acinetobacter baumannii using the Kirby Bauer disc diffusion and agar well   method. The results showed that the antimicrobial zone of inhibition increased with an increase in concentration of the CuNPs, an  average diameter of 25 mm at 7 mg/ml, 22 mm at 5 mg/ml and an average diameter of 13 mm at 2 mg/ml of 100% DMSO.  Nanoparticles at 0.25 mg/ml and 0.5 mg/ml concentration failed to produce any clear zone across all the test organisms while only Enterococcus faecalis was sensitive with a clear zone diameter of 10 mm at 1 mg/ml CuNPs. MRSA has the least susceptibility: 9 mm clear zone diameter at 2 mg/ml and at 7 mg/ml clear zone diameter of 20 mm, relative to other tested organisms. The test organisms were not sensitive to the following conventional antibiotics: Cefuroxime, Ceftazidime, Erythromycin, Amoxicillin/Clavulanic acid and Cloxacillin, but only sensitive to Gentamicin, Ceftriaxone and Ofloxacin. MRSA on the other hand was not sensitive to all the eight antibiotics tested but susceptible to the CuNPs. The results obtained from this study indicated that copper nanoparticles can be used in the food industry to control both Gram positive and negative bacteria tested. Keywords: Synthesis, Copper nanoparticles, Antimicrobial activities, Bacteria.

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Extended-spectrum β-lactamases (ESBLs) continue to be a major challenge in clinical setups worldwide, conferring resistance to the expanded-spectrum cephalosporins. The present study focused on the prevalence of ESBL-producing E. coli clinical isolates among patients diagnosed of Wound and Urinary Tract Infections attending Federal Teaching Hospital Abakaliki. A total of one hundred and ninety two clinical isolates of E. coli was studied for their susceptibility patterns to cephalosporin antibiotics and detection of ESBL producers was carried out by double disc synergy test (DDST) and Brilliance ESBL Agar. Of the 192 isolates tested for their antibiogram, 19(9.9%), 41(21.4%), 132(68.7%); 48(25.0%) and 144(75.0%) isolates were from wound, high virginal swab, urine, male and female respectively. The isolates showed higher susceptibility to cefepime (a 4th-generation cephalosporin) with percentage susceptibility of 78.9, 85.4 and 73.5 to the isolates from wound, HVS and urine respectively. Higher resistance was recorded among the 3 rd-generation cephalosporins which include Cefotaxime (63.4%), Ceftriaxone (57.9%), and Cefpodoxime (73.7%). Among the resistant isolates of E. coli, 20 isolates were phenotypically confirmed ESBL producers by the DDST and Brilliance ESBL Agar methods. Ten (10) ESBL producing E. coli was confirmed using DDST method whereas 15 ESBL producing E. coli was confirmed using the Brilliance ESBL Agar. Brilliance ESBL Agar was found to be better than DDST in the detection of ESBLs. Continuous monitoring of drug resistance and regulating the use of cephalosporin drugs in our hospitals is vital for proper infectious disease management and treatment.

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