Abstract

Background: The production of beta-lactamase enzyme by some Gram-negative bacteria is one of the common mechanisms of resistance to beta-lactam antibiotics.



Methods: In this study, we isolated E. coli and K. pneumonia from infected urine samples and then determined the existence of the (CTX-M) resistant genes in ESBL-producing bacterial isolates of E. coli and K. pneumonia, and determined the antibacterial effect of Neem plant (A. indica) ethanolic extract against these bacteria.



Results: For Phenotype detection of ESBLs we used the hybrid disc method, 12 available commercial antibiotics were used in the Antibiotic susceptibility test and the tested bacterial isolates showed high resistance to these antibiotics. The PCR results confirmed that the ESBL-producing isolates E. coli and K. pneumonia had the CTX-M gene and the CTX-M-1 gene. The antibacterial activity of ethanolic extract of Neem plant against this bacteria was done by agar well diffusion method at different concentrations (50, 100, 200, and 300mg/ml) and evaluated then the inhibition zone diameters were (2, 4, 5 and 6mm) against E.coli(ESBL+) and (0, 2, 5 and 6mm) against K. pneumonia(ESBL+) respectively while E.coli (ESBL -) was (7, 6, 4 and 3 mm) respectively and with k .pneumonia (ESBL-) it gives (7, 6, 3 and 2 mm) respectively. The MIC for E.coli (ESBL+) was 125mg/ml, while the MIC for E.coli (ESBL-) was 62.5 mg/ml. The MIC for K. Pneumonia (ESBL-) was at a concentration of 31.25mg/ml and for K. Pneumonia (ESBL+) was at 62.5mg/ml.



Conclusion: The ethanolic Extract of Neem plant at different concentrations has antibacterial activity against (ESBL+) and (ESBL-) bacterial isolates of E. coli and K. pneumonia.