Infections are the major cause of life-threatening in neutropenic patients. Prompt administration of empirical anti-microbial treatment is considered vital before identifying the causative pathogens. Blood cultures remain essential and the « gold standard » for confirmation of bacteremia. The yield of blood cultures is optimal when strict procedure guidelines (collection, incubation and laboratory/clinical data correlation) are followed
Our aim is to determine the profile of pathogens and their susceptibilities and to identify the rate of contamination for improving diagnosis and better quality control
In this retrospective study, 1006 blood cultures were obtained from 278 neutopenic patients, children and adults, hospitalized at the Hematology-Pediatric Oncology yard of the University Hosptal Ibn Rochd - Casablanca, during a period of 6 months, from January to June 2013. Blood cultures were collected in aerobic, anaerobic and mycosis bottles. The incubation used the BACTEC system. Identification and antimicrobial susceptibility testing of the isolates was performed using Mueller Hinton according to CLSI 2012. For the yeast, FUNGITEST BIORAD and ETEST Biomerieux were used.
Of 1006 blood cultures analysed, 620 (62%) were aerobic, 130 (13%) anaerobic and 256 (25%) mycosis. Two hundred twenty (22%) were evaluated pathogens, 177 (23%) strains of germs and 50 (18%) fungal isolates. The Gram-positive cocci were the most frequently isolated, accounting for 109 (61%). The Coagulase-Negative Staphylococcus (CNS) was found in 78% (85) but only 16 were considered as pathogens. All the strains were methicillin-resistant without any resistance to vancomycin or teicoplamine. The gram negative bacteria (GNB) were found in 35% (61) isolates with Klebsiella pneumonia in 51%, Escherichia Coli in 29% and Enterobacter in 7%. Non-fermenting bacillus accounting for 13%. 68% among Klebsiella were extended spectrum of beta lactamases (ESBL ). Three GNB were acinetobacter Baumani resistant to imipenem and 3 pseudomons aeruginosaresistant to Ceftazidim. Blood cultures identified candida in 97% of isolates, candida parapsilosis was the most frequent (72%) followed by candida Krusei (9%) , Tropicalis (7%) and Albicans (3%). Other yeast was found in 9%. 13% of candidas were resistant to Amphotericin B and 22 % to fluconazole.
The pathogen profile showed predominance of gram negative bacteria, remain different than the one found in developing countries. Strict procedure guidelines for the realisation of blood cultures should be set up, will help to increase the diagnosis yield and adequate management.
No relevant conflicts of interest to declare.
Asterisk with author names denotes non-ASH members.
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