Determination of the MIC of antibiotics for gram negative microorganisms isolated from the sterile sites of children hospitalized in Rasool Akram hospital|
Noorbakhsh, S; Farhadi, M & Tabatabaei, A
Background: The increased prevalence of resistant gram negative organisms in our hospital is documented in our previous retrospective study during 1996-1998. The present study was conducted to determine the resistance frequency of gram negative organisms responsible for infection in children.
Methods: In a descriptive prospective study within 2 years (2002-2003). We surveyed 101 children aged 1 month-14 years hospitalized in pediatric and ENT wards of Rasool Akram hospital selected by simple sampling. All gram negative organisms isolated from blood, CSF and other sterile sites (middle ear; mastoid; sinus; trachea) were evaluated first by disc diffusion and then E-testing for MIC to find appropriate antibiotics for the isolated organisms.
Findings: The isolated germs consisted of Pseudomonas aeroginusa (47.5%), Klebsiella pneumoniae (22.8%); E. coli (17.8%), entrobacter and Acinetobacter (4.9%), Fusobacter and Salmonella paratyphi (1%). Resistance of pseudomonas was high (80%) for gentamycin; cotrimoxazole and rifampin; moderate (50%) for ceftazidim and amikacin, but low (<15%) for imipenem. Resistance of Klebsiella to ampicillin, gentamycin, amikacin, cotrimoxazole and ciprofloxacin was high (70%), but showed lower resistance for ceftriaxone and imipenem (30%). More than 90% of E. coli was resistant to ampicillin, cotrimoxazle, with moderate resistance (20%) to gentamycine and cephalexin. Resistance of Entrobacter to ceftriaxon was less than 40%. More than 80% of Acinetobacter was sensitive to amikacin and cotrimoxazole.
Conclusion: Ceftazidime, despite increasing resistance of pseudomonas to it, combined with amikacin is still adequate for empiric treatment in admission. For other resistant types, cefepime or imipenem is useful. For Klebsiella pneumoniae, ceftriaxone and imipenem; for E. coli, amikacin or ceftriaxon; and if it does not respond imipenem or azteronam. Cefriaxon is the best choice for early treatment of Enterobacter infections.
Gram negative , Antibiotic , Antibiotic resistant , Pseudomona infection , MIC