GRAM-NEGATIVE BACTERIA ISOLATED FROM BLOOD CULTURES IN A GENERAL-HOSPITAL

This study reviews 2205 significant positive blood cultures from 534 p atients treated at the Meir General Hospital during the period 1988-19 90. In addition, a comparison was made with a previous survey performe d twelve years ago (1976-1978). Gram negative rods accounted for 68% o f the septicemia cases indicating a small increase since the former su rvey (61.2%). The order of Gram negative frequencies was E. coli, Urea positive Gram negative bacteria (UPGNB) Klebsiella, Enterobacter, Pse udomonas (in a decreasing order). E. coli was most predominant in both surveys in the internal wards while UPGNB were predominant in the ger iatric-rehabilitation wards. A significant rise in frequency of cephal othin and sulfamethozaxole-trimethoprim resistant E. coli isolates was noticed. In UPGNB, Klebsiella and Pseudomonas a significant increase in resistant isolates to cephalothin, gentamicin, sulfamethoxazole-tri methoprim and chloramphenicol was found. As for tobramycin, amikacin a nd mezlocillin, it is clear that the Gram negative bacteria have gaine d resistance to these drugs over recent years. Resistance frequencies of above 20% were found in Enterobacter and Pseudomonas for the newer antimicrobial agents such as: ceftriaxone, cefotaxime or ceftazidime. Low resistance is still seen in all above bacteria against ciprofloxac in and ofloxacin. The minimal inhibitory concentrations (M.I.C.) of ge ntamicin, cephalothin, cefotaxime, ceftazidime ceftriaxone and sulfame thozaxole-trimethoprim do not exceed the range of 30 mu g/ml. The M.I. C. range of the quinolone ciprofloxacin does not exceed 6 mu g/ml.