Bloodstream infections and antimicrobial resistance patterns in neonatal intensive care unit in Shiraz

Objectives: Bloodstream infections remain a leading cause of morbidity and mortality in neonatal intensive care units (NICU) worldwide. Commonly isolated NICU pathogens are increasingly resistant to standard antimicrobial treatment regimes. The primary aim of this study was to determine the burden of bloodstream infections (BSI) in NICU wards in a tertiary teaching hospital and to describe the spectrum of pathogens isolated together with their drug susceptibility patterns. Methods: A review of neonatal blood cultures submitted to the Professor Alborzi Clinical Microbiology Research Center, Nemazee teaching Hospital, was conducted from August 2014 through November 2018. Results: There were 244 culture-confirmed episodes of BSI in patients admitted to NICU. Gram negative organisms accounted for most pathogenic cultures (162/244, 66.4%).Most bacterial isolates were non-fermenting gram negative rods (94/244, 38.5%), with most frequently Acinetobacter spp. (35/244, 14.3%), Stenterophomonase maltophilia (31/244, 12.7%) and Pseudomonase spp. (18/244, 7.4%). Gram positive isolates (74/244, 30.3%) with most frequently Enterococcus spp. (43/244, 17.6%), Streptococcus spp. (16/244, 6.5%) and Staphylococcus spp. (13/244, 5.3%). Finally, Enterobacteriacea (67/244, 27.4%) with Klebsiella spp. (28/244, 11.5%), E. coli (13/244, 5.3%) and Enterobacter spp. (7/244, 2.9%). Methicillin-resistant Staphylococcus aureus were 69.2 % and 85.7% of gram negative isolates were extended spectrum b-lactamase (ESBL) producers. Vancomycin resistance was detected in 81.4% of the isolated enterococci. The most effective antibiotics against Stenotrophomonas maltophilia were Trimethoprim/Sulfamethoxazole (96.4%), Levofloxacin (93.3%), Colistin (85%), Tigecyclin (80.6%), Ciprofloxacin (47.4%) and Amikacin (42.1%). E. coli isolates showed high resistance to ampicillin (100%), ceftriaxone (92.3%), cefotaxime (92.3%) and cefuroxime (90.9%), However, they showed good susceptibility to colistin, tigecyclin, carbapenem and piperacillin- tazobactam (100%). Klebsiella spp. exhibited high resistance to commonly used antibiotics such as; ampicillin (100%), cefuroxime (94.7%), cefotaxime (80.8%) and good susceptibility to colistin (100%), levofloxacin (91.7%), imipenem (77.8%) and gentamycin (67.4%).Conclusion: Many bacterial BSI isolates were resistant to current empiric antibiotic regimens. Regular microbiological and clinical surveillance of BSI in NICUs is required to inform appropriate antibiotic protocols and monitor the impact of infection prevention strategies

Keywords:

Antimicrobial resistance , Bloodstream infection , Neonatal intensive care unit