Gram negative bacteria isolated from blood cultures in a general hospital

This study reviews 2205 significant positive blood cultures from 534 patients treated at the Meir General Hospital during the period 1988-1990. In addition, a comparison was made with a previous survey performed twelve years ago (1976-1978). Gram negative rods accounted for 68% of the septicemia cases indicating a small increase since the former survey (61.2%). The order of Gram negative frequencies was E. coli, Urea positive Gram negative bacteria (UPGNB) Klebsiella, Enterobacter, Pseudomonas (in a decreasing order). E. coli was most predominant in both surveys in the internal wards while UPGNB were predominant in the geriatric-rehabilitation wards. A significant rise in frequency of cephalothin and sulfamethoxazole-trimethoprim resistant E. coli isolates was noticed. In UPGNB, Klebsiella and Pseudomonas a significant increase in resistant isolates to cephalothin, gentamicin, sulfamethoxazole-trimethoprim and chloramphenicol was found. As for tobramycin, amikacin and mezlocillin, it is clear that the Gram negative bacteria have gained 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 ciprofloxacin and ofloxacin. The minimal inhibitory concentrations (M.I.C.) of gentamicin, cephalothin, cefotaxime, ceftazidime ceftriaxone and sulfamethoxazole-trimethoprim do not exceed the range of 30 micrograms/ml. The M.I.C. range of the quinolone ciprofloxacin does not exceed 6 micrograms/ml.