Microbial resistance is an increasingly serious threat to global public health and it is linked to patient's age, immune status, and also antibiotic overuse or misuse and repeated hospitalizations. The high incidence of infections caused by multidrug-resistant bacteria requires rethinking the first-line therapeutic schemes.
Aim: Retrospective study of the etiologic and antibiotic resistance profile of the bacterial strains isolated from immunocompromised hosts diagnosed with severe systemic infections, aimed at gaining a better understanding of the potential infectious sources and optimizing the antibiotic therapy.
Material and methods: 178 cases of severe sepsis associated with immunosuppression (caused by diabetes, malignancies, liver cirrhosis, chronic alcohol abuse, kidney failure) were admitted to the "St. Parascheva" Infectious Diseases Hospital Iaşi in the interval January 2011- December 2014.
Results: The mean age of the study patients was 61 years, most patients being female (53%) and living in urban areas (51%). The causal agents were: Escherichia coli (20.2%), Klebsiella pneumoniae (16.8%), Pseudomonas aeruginosa (14.6%), Methicillin-Sensitive Staphylococcus aureus (MSSA) (11.2%), Enterococcus spp. (10.1%), Methicillin-Resistant Staphylococcus aureus (MRSA) (8.9%), Proteus spp.(5%), Acinetobacter baumanii (5%), Streptococcus pyogenes (1.6%), Staphylococcus epidermidis (1.1%) and Citrobacter (0.5%). As to the resistance profile the following were found: 100% susceptibility of MRSA and Enterococcus species to vancomycin, as well as for the Enterococcus species; 27% of E. coli strains were resistant to beta-lactams and 20% of Klebsiella pneumoniae to carbapenems. Antibiotic therapy associated two or three drugs with an immediate result and a favorable outcome in 84.2% of the cases.
Conclusions: The etiological agents implicated in the occurrence of severe sepsis in patients with acquired immunosuppression were Gram-positive bacteria (GPB) as well as Gram-negative bacteria (GNB) with moderate resistance to usual antibiotics. The infections caused by GNB were predominant in immunocompromised patients, but also in those with associated urinary and respiratory tract infections and chronic indwelling urinary catheters. In our severe sepsis patients Gram positive bacteria caused mainly skin and joint infections.