Change in the Trend of Bloodstream Infections Caused by Non-fermenting Gram-negative bacilli and Enterobacteriaceae, 1389-1396, Shiraz, Iran

Introduction and Objectives: Bloodstream infections (BSIs) caused by Gram-negative (GN) bacteria is associated with significant morbidity and mortality. We aimed to investigate the prevalence of the most common GN bacteria belonging to the family Enterobacteriaceae (Enterobacter, Escherichia coli, and klebsiella spp.) and the non-fermenting Gram-negative bacilli (NFGNB) (Pseudomonas spp., Acinetobacter spp., Stenotrophomonasmaltophilia) causing BSIs in hospitalized patients in Shiraz during 8 years.Materials and Methods: We evaluated all NFGNB and Enterobacteriacea, isolated from blood samples by BACTEC system between 1389 and 1396. These samples were obtained from patients admitted mainly to the eight hospitals (Nemazee, Al-zahra, Central hospital (MRI ), Ghadir, Dena, Shahid Rajaee, Ordibehesht, and Hafez) in Shiraz. Identification was done by standard microbiologic methods and API system in Professor Alborzi Clinical Microbiology Research Center.Results: Among 7646 BSI during the study period, 1338 isolates (37.6%) of Enterobacteriaceae and 2377(31.1%) NFGNB were identified. Escherichia coli was the most prevalent Enterobacteriaceae, accounting for 9.7% of isolates, followed by Klebsiella spp. 5%, and Enterobacter spp. 2.7%. Stenotrophomonasmaltophilia was the most common NFGNB, accounting for 11.9% of the isolates, followed by Pseudomonas spp.11.1%, and Acinetobacter spp. 8.1%. The rate of NFGNB isolation was as follows: 22% in 1389-1390 to 11.7% in 1391, 13.9% in 1392, 32.6% in 1394, 56.3% in 1395 and 52.6% in 1396, and the rate of Enterobacteriacea during study period was 29.3% in 1389-1390, 11.7% in 1391, 14.4% in 1392, 28.8% in 1393, 19.6% in 1394, 15.7% in 1395 and 12.4% in 1396.Conclusion: These data will help to improve the quality of antibiotic prescribing empirically and it needs more investigation.

Keywords:

Bacteremia , Gram-Negative Bacteria , Enterobacteriaceae