Microbiological and Resistance Patterns of Blood Cultures Clinical Isolates at Moulay Ismail Military Hospital of Meknes , Morocco . A Four-Year Period Retrospective Study : 2011-2014

Introduction: Septicemia poses a problem of diagnosis and treatment in hospitals. There is lack of data on the epidemiological patterns of this topic in Morocco. Indeed, the goal here is to describe microbiological patterns and antimicrobial resistance of clinical microorganisms isolated from blood cultures of patients hospitalized in different departments of the Moulay Ismail Military Hospital in Meknes, Morocco, throughout a four-year period (2011-2014). Material and Methods: In this study, aerobic and anaerobic blood cultures are analyzed retrospectively. Samples are processed in the BD BactecTM 9050. All grown microorganisms were identified by Api system (BioMérieuxTM) or rapid specific kits (BioRadTM). The antibiotics susceptibility testing was conducted by disk diffusion method on appropriate Mueller-Hinton agar media according to CA-SFM or EUCAST recommendations (guidelines of French committee and/or European committee on antimicrobial susceptibility). Resistance against carbapenems is confirmed by modified Hodge test. Results: A total of 712 blood cultures performed for 371 patients gave a positivity rate of 31.3%. Main of inpatients were hospitalized in the intensive care unit (n=116) versus 41 in surgical departments. The mean of age was 55.6 years-old (13 to 87) with a sex ratio m/f of 2.74. The involved microorganisms (n=120) were Staphylococcus sp (50/120 or 41.67%), Staphylococcus aureus (20/50 or 40%), Enterobacteriaceae (43/120 or 35.83%) among which Escherichia coli is the most encountered (21/43). Streptococci/Enterococci were noted in 8.33% (10/120) containing a case of Lactococcus lactis cremoris endocarditis. Non-fermenter Gram-negative bacilli represented 6.67% (8/120). Lowest frequencies are observed with other kinds of aerobic, anaerobic flora; and Candida albicans. Resistance to methicillin reached 25% (n=5) with Saureus (MRSA) versus 36.67% when CoNS are considered (n=11). The amount of extended spectrum beta lactamase-producing Enterobacteriaceae (ESBLE) was 37.21% (16/43), mainly observed with Escherichia coli (n=11) and Klebsiella pneumoniae (n=8) while carbapenemase-producing Enterobacteriaceae (CPE) were seen in three cases of extremely drug-resistantstrains: K pneumoniae, Enterobacter cloacae and E coli. Non-fermenter Gram-negative rods isolates were four wild strains of Pseudomonas aeruginosa and Ppaucimobilis and three imipenem resistant Acinetobacter baumannii. Resistance patterns against other antibiotics (fluoroquinolones,aminoglycosides, .)is reported. Conclusion: Staphylococcus sp and Enterobacteriaceae are the predominant cause of septicemia in our settings. Empirical antimicrobial therapy might repose on the fact that ESBLE and MR-Staphylococci have to be expected in first for more efficiency of septicemia management. In the other hand, the reinforcement of hand washing and screening for patients carrying resistant strains is recommended in our settings, as well as culture free diagnostic methods (TAANs and MALDI-TOF) for more efficient diagnosis and accurate antimicrobial therapy.