[A 7-year survey of strains identified in blood cultures in a clinical hematology unit]. / Etude sur sept ans des isolats d'hémocultures dans un service d'hématologie clinique.

ABSTRACT

GOAL This study had for aim to analyze the epidemiology of strains identified in blood cultures (hôpital d'instruction des armées Percy, Clamart, France, hematology unit) to compare the rate of identified micro-organisms with literature data, and to search for a possible correlation between antibiotherapy management and evolution of resistance profiles. MATERIAL AND METHODS: All the micro-organisms (N = 690) collected over seven years (January 1996 to December 2002), from blood cultures of hospitalized patients in conventional and sterile sector were studied. RESULTS: Gram positive cocci rate (GPC) was 62.6% and Gram negative bacilli (GNB) 31.3%. Evolution in time showed a decrease of GPC and an increase of GNB, notably the non fermenting Gram negative bacilli, leading to an equal rate by 2001-2002. The most frequently identified species were Staphylococcus epidermidis (36.4%), Escherichia coli (8.7%), Pseudomonas aeruginosa (6.8%), and Staphylococcus aureus (4.9%). The rate of methicillin-resistant staphylococci was 63.6%. Fifty-five percent of E. coli strains had a penicillinase phenotype. Pseudomonas aeruginosa resistance was 8.5, 8.5, 6.4 and 8.5%, respectively for ceftazidime, piperacillin-tazobactam, imipenem, and amikacin. CONCLUSION: This study showed a tendency to inversion of former bacteremia epidemiology with increasing negative Gram bacilli. It justifies the antibiotherapy protocols adopted in the hematology unit.