Clinico-Microbiological Investigation on Fosfomycin and Tigecycline Resistant Gram-Negative Bacilli Isolated from Urinary Tract Infections: A Potential Resurgence

 Traditional antibiotics are no longer as effective as before for controlling pathogens associated with urinary tract infections (UTI), which shows the necessity of developing new and more effective antibiotics.

 The current study aimed to evaluate in vitro susceptibility of fosfomycin and tigecycline towards common antibiotic-resistant Gram-negative bacilli isolated from the urinary tract. Besides, clinico-microbiological on fosfomycin and tigecycline resistant Gram-negative bacilli was investigated.

 In this descriptive cross-sectional study, 150 resistant Gram-negative bacilli were isolated from urine specimens send for culture, and antibiotic susceptibility assessment to the Division of Microbiology of Sina Hospital affiliated to Tabriz University of Medical Sciences which were collected from April-September 2017 are included. Antibiotic susceptibilities were evaluated according to the Clinical and Laboratory Standards published by the Institute and the criteria of the Food and Drug Administration.

 Of 150 isolates, 138 (92%) were susceptible, and 2 (1.3%) were resistant to both fosfomycin and tigecycline, as confirmed by disk diffusion and Epsilonmeter tests. The difference was statistically significant (P = 0.001).

 Based on the results, resistance to the conventional antibiotics prescribed for the treatment of UTI was significantly high. Fosfomycin and tigecycline have an appropriate antimicrobial activity towards Gram-negative-resistant isolates involved in UTIs.