PURPOSE: To determine the predominant pathogens and their antimicrobial susceptibility in intensive care unit in a tertiary care teaching hospital.
METHODS: From January 2004 to December 2005, all microbial isolates from patients in ICU at Makassed general hospital (MGH) in Beirut, Lebanon were collected. All bacterial strains were identified according to standard microbiological procedures. Antimicrobial susceptibility testing of isolates was performed by disk diffusion susceptibility testing. Intermediate sensitive results were classified as resistant. Interpretive criteria for Klebsiella pneumoniae and Escherichia coli expressing an ESBL phenotype were defined by resistant to Amoxicillin, Amoxicillin/calvulonic acid, Ticarcillin, Mecillinam, Cefalotin, and Ceftazidime. For each isolate, the following information was retrieved: date of sampling, source of culture, and patient’s name.
RESULTS: A total of 638 adult patients admitted to ICU at MGH during the 2 years study period. 586 isolates were obtained from 225 patients. 66 isolates (11.3%) were Candida species, the rest were bacterial isolates. The source of the cultures was respiratory in 314 (53.6%), blood in 118 (20.1%), urine in 74 (12.6%), wound in 25 (4.2%) and central venous catheter tip in 15 (2.6%). The most common gram negative microorganisms were Acinetobacter baumanii 111(18.9%), Pseudomonas aeruginosa 110 (18.7%), Escherichia coli 46 (7.8%) and Klebsiella pneumoniae 23 (3.9%). The most common gram positive microorganisms were Staphylococcus coagulase negative 66 (11.3%) and Staphylococcus aureus 50 (8.5%). The antimicrobial sensitivity of Acinetobacter baumanii was 18% to Piperacillin-tazobactam, 20% to Imipenem, 9% Ceftazidime, 7% to Amikacin, and 3% to Ciprofloxacin. All Acinetobacter baumanii isolates were sensitive to Colistin. The antimicrobial sensitivity of Pseudomonas aeruginosa was 75% to Amikacin, 72% to Piperacillin-tazobactam, 61% to Imipenem, 51% Ceftazidime, and 50% to Ciprofloxacin. The Staphylococcus aureus isolates were 61% MRSA. The rate of ESBL was 13% among Escherichia coli and 4% among Klebsiella pneumoniae.
CONCLUSION: There is an emergence of multi-drug resistant Acinetobacter baumanii strain in MGH-ICU.
CLINICAL IMPLICATIONS: Awareness of the results of this study will help in antimicrobial selection, infection control strategies and successful interventions.
DISCLOSURE: Hani Lababidi, None.