Abstract
The final effluent for 5 hospitals (3 governmental and 2 private) was surveyed in order to study their bacterial population including, total viable bacteria (TVB) and total coliform (TC) counts/ml, macro and micro-morphology of the isolated and identification of the isolated and purified bacterial strains to the specific level confirmed using API strips and its code index matching computer program. Counts allover the study showed figures beyond the international permissible limits, ranging between 1x 10(3) - 1 x 10(7) cfu/ml. Identification confirmed that the bacterial population is composed of 27 species belonging to 17 genera; Escherichia coli 1, Klebsiella pneumoniae, K. ornithinolytica, Providencia alcalifaciens, Salmonella arizonae, Enterobacter cloacae, E. saburiae, E. gergoviae, Yersinia pestis, Citrobacter frundii, Serratia marcens, Pseudomonas aeruginosa, P. putida, Flvimonas oryzihabitans, Chryseomona luteda, Stenotrophomonas maltophila, Shewanella putrifaciens, Aeromonas hydrophila, A. salmonicida, Chryseobacterium meningiosepticum, Ch. Indologenes, Pasteurella multocida, Pas. pneumotropica and Moraxella catarrhalis, affiliated to 5 families; Enterbacteriaceae, Pseudomonadaceae, Vibrionaceae, Pasteurellaceae and Moraxellaceae. Gram negative bacterial strains dominated specially those of family Enterobacteriaceae and Pseudomonadaceae. The higher distribution patterns amongst the isolated strains, from almost all samples were for E. coli 1, followed by Enterobacter cloacae and Chryseobacterium meningiosepticum.. Antibiotic assay (9 antibiotics from different families) on 153 representative strains using antibiotic serial dilutions from 10 up to 100 mu g/ml-to determine MIC (s), MBC (s) and the MIC/MBC indexes. All the studied strains exhibited resistance to at least 3 of the 9 tested antibiotics. Many bacterial isolates resist the whole 9 antibiotics and to a concentration of more than 100 mu g/ml. The majority of the resistance strains were gram negative and the mechanism of action proved to be inhibitory.