Some Studies on the bases of Antibiotic Resistance in Gram Negative Bacteria Isolated from lsmailia City Drinking Water

Abstract

Gram-negative bacterial population was detected in drinking water at eight sites in Ismailia city. Antibiotic assay inculding senstivity test, MIC and MBCdetermantions were proceded. Standard membrane filtration method on nutrient agar, MacConky agar and Salmonella & Shigella agar was followed for detection, isolation, enumeration and preliminary identification. Out of total bacterial isolates 593 isolates more than 43.3% (261 isolates) were gram-negative bacteria blonging to I 0 different genera and 13 species.

Antibiotic profiles of this gram negative strains were plotted against I 0 antibiotics namely ampicillin, cephradine, cephalexin, tetracycline chloramphinicol, erythromycin, nitrofurantoin, gentamicin, streptomycin and rifampicin.

The majority of isolates (89.3%) showed ampicillin resistance, followed by erythromycin (82%), cephalexin (71.6%) and cephradine (67.4%). Most of the tested isolates (76.6%) were resistant to at least two antibiotics (multiple antibiotic resistant, MAR). MAR strains represented 93.8,78.6, 68.6 and 47.6% of Enterobacter cloacae, Escherichia coli,