Distribution and antibiotic susceptibility of pathogens isolated from adults with hospital-acquired and ventilator-associated pneumonia in intensive care unit

Gram-negative agents were isolated in 95.2%. Generally, the most common pathogens were Acinetobacter spp. and Pseudomonas aeruginosa, accounting for over 60% of isolates. The isolates of Acinetobacter spp. in HAP and VAP had low susceptibility to the 3rd generation cephalosporins, aminoglycosides, fluoroquinolones (0-10%). The rate of susceptibility to piperacillin-tazobactam was below 15%, whereas for carbapenems and 4th generation cephalosporins it was about 15-20%. Isolates of P. aeruginosa from HAP and VAP showed low susceptibility to ciprofloxacin and gentamicin (below 10%), followed by amikacin (25%), while the rate of susceptibility to carbapenems and 4th generation cephalosporin was 30-35%. Furthermore, 86% of isolates of P. aeruginosa non-susceptible to carbapenems were also non-susceptible to ciprofloxacin. The highest level of susceptibility from both groups was retained toward piperacilin-tazobactam. In ICU within our settings, with predominance and high resistance rates of Gram-negative pathogens, patients with HAP or VAP should be initially treated with combination of carbapenem or piperacillin-tazobactam with an anti-pseudomonal fluoroquinolone or aminoglycoside. Colistin should be used instead if Acinetobacter spp. is suspected. Vancomycin, teicoplanin or linezolide should be added only in patients with risk factors for MRSA infections.