Evaluating the Potential of Nitrofurantoin and Fosfomycin for E. coli UTIs: A Susceptibility Study

This study was designed to find the susceptibility of Nitrofurantoin and Fosfomycin among urinary isolates of Escherichia. coli. Four hundred (400) urine samples were collected for susceptibility of nitrofurantoin and fosfomycin among urinary isolates of E. coli. All indoor and outdoor patients’ urinary samples yielded growth of E. coli. Mid-stream urine specimens were inoculated on blood agar and CLED agar and incubated at 35 ± 2 ℃. Growth was observed, and Escherichia coli was identified by Gram staining, Catalase, Motility test and API 20E (Bio murex) as per standard procedure. Antimicrobial susceptibility testing of isolates for nitrofurantoin and fosfomycin was carried out by the modified Kirby-Bauer disc diffusion method according to CLSI guidelines ATCC 25922. E. coli was used as a quality control strain. A total of 400 samples were tested susceptibility of nitrofurantoin and fosfomycin among urinary isolates of E. coli during this period. A total of 400 samples yielded the growth of E. coli, out of which 178 (44.5%) were male and 222 (55.5%) were female samples. Among males, 18 (10%) were tolerant to nitrofurantoin, and 2 (1.1%) were tolerant to fosfomycin. Among females, 9 (4.09%) were susceptible to nitrofurantoin while 6 (2.72%) were susceptible to fosfomycin. Among age groups below 45 years old, 6 (4.76%) were tolerant to nitrofurantoin, and 2 (1.58%) were sensitive to fosfomycin. Between 46–66 years old, 4 (2.81%) were sensitive to nitrofurantoin, and 3 (2.11%) were sensitive to fosfomycin. Between 67–90 years old, 17 (12.87%) were sensitive to nitrofurantoin, and 4 (3.03%) were tolerant to fosfomycin. Fosfomycin and nitrofurantoin showed good susceptibility in urinary isolates of E. coli and can be used empirically in our setup.