Antibiotic resistance of non-fermenting Gram-negative bacilli isolated at a large Infectious Diseases Hospital in North-Eastern Romania, during an 11-year period.

Abstract

Increased antibiotic resistance of non-fermenting Gram-negative bacilli (NFGNB) associated with increased morbidity and mortality makes the infections they produce a major public health problem. This study aims to assess the evolution of antibiotic susceptibility and the level of NFGNB antibiotic resistance. We carried out a retrospective study on 994 NFGNB strains which had been isolated in the Clinical Laboratory of the "Sf. Parascheva" Clinical Hospital of Infectious Diseases, Iaşi, during a period of 11 years (2008-2018). Of the 994 NFGNB analyzed, 322 were Acinetobacter spp. and 672 Pseudomonas aeruginosa. Also, 882 NFGNB were isolated from non-sterile sites, in which there was a higher burden of P. aeruginosa strains (n=617). Acinetobacter spp. presented over 70% resistance to the majority of antibiotics. Three pandrug-resistant P. aeruginosa strains were identified. The rate of colistin resistance was 2.91% for P. aeruginosa and 3.33% for Acinetobacter spp. A comparative analysis of the antibiotic susceptibility of strains isolated from non-sterile sites versus sterile sites revealed statistically significant differences only for Acinetobacter spp. The percentage of resistant strains was significantly higher in tracheobronchial aspirate compared to sputum. The results show that Acinetobacter spp. is substantially more resistant to antibiotics compared to P. aeruginosa and that the use of medical devices can favor the occurrence of infections with multidrug-resistant strains.