[Antimicrobial resistance of the bacteria isolated from blood cultures in 2007].

Introduction: Antimicrobial resistance become emerging global problem. Particularly dramatic increase in the number and type of bacteria resistant to numerous and structurally different antibiotics has taken place in the last two decades.

Materials And Methods: A total of 558 strains of different bacteria isolated from blood cultures during 2007 were tested to susceptibility to different antibiotics by disc diffusion method according to CLSI. All strains were isolated and identified in the laboratories of Microbiology Center at the Institute for Public Health in Novi Sad. A total of 7748 blood cultures were processed and microorganisms were isolated from 558 of them. Blood samples were taken from the patients hospitalized in the Institutes and Clinics of Novi Sad Clinical Center and Institute for Health Care of Children and Adolescents in Novi Sad

Results: The structure ofpathogens shows that the most frequent isolates are Gram-positive bacteria, above all coagulase- negative staphylococci with 285 isolates (51,1%) followed with Enterococcus spp (41 isolates - 6,8%). Percentage of resistance to Methicillin in staphylococci strains was 66,7%; all isolates was susceptible to Vancomycine. Enterococcus spp showed 13,2% resistance to Vancomycine. Among Gram-negative pathogens, we find that the most frequent is Klebsiella spp with 40 isolates (7,2%) and have high resistance to wide spectrum Cephalosporins - 82,5%. Acinetobacter spp participate with 41 isolates (7,3%) and 43,9% isolates are resistant to Imipenem Also, Pseudomonas aeruginosa (20 isolates) shows high resistance to Imipenem (40%) but lower resistance to wide spectrum Cephalosporines (27,8%).

Conclusion: Having compared the resistance to antibiotics in 2002 and 2007 speak for the trend of growing antimicrobial resistance to the very antibiotics which are recommended as the empiric or initial therapy-wide spectrum Cephalosporins, Fluoroquinolons and Imipenem.