Molecular characterization of nitrofurantoin resistant uropathogenic Escherichia coli in Al-Najaf province, Iraq

Background: Nitrofurantoin is a drug that is often used to treat urinary tract infections caused by uropathogenic Escherichia coli (UPEC). This study aims to investigation regarding the molecular characterization of nitrofurantoin resistance in UPEC, by utilizing polymerase chain reaction (PCR) to detect genes relevant for nitrofurantoin resistance. Addition, study the epidemiology and evolution of nitrofurantoin resistance in UPEC by using Multilocus sequence typing (MLST).Materials and Methods: Isolates from midstream urine samples were analyzed for nitrofurantoin and other antibiotic resistance using VITEK 2. The nitrofurantoin-resistant genes (NfsA, NfsB, and RibE) were identified using PCR. MLST analysis was used to determine the sequence type (STs) of UPEC strains resistance to nitrofurantoin.Results: Among 441 urine samples from suspected UTI patients, 380 showed significant bacteriuria (≥ 105 CFU/ml). 172/380 (45%) yielded E. coli with varied antibiotic resistance profiles. Our investigation revealed 33 nitrofurantoin-resistant UPEC isolates with MICs (≥ 128) Mg/ML. The PCR results showed that 23 out of 33 nitrofurantoin-resistant UPEC isolates harbored one or two of nitrofurantoin resistance genes. NfsA, NfsB, and RibE were positive in (18/33; 54%), (9/33; 27%) and (3/33; 9%) of the isolates, respectively. In analyzing the results of our MLST study on nitrofurantoin-resistant UPEC isolates, A total of 12 different sequence types STs were identified, with ST69 and ST10 being the predominant clones and present in six and four isolates, respectively.Conclusions:These findings highlight the urgent need for research on molecular mechanisms of nitrofurantoin resistance in UPEC and the importance of sequence type STs to guide treatment regimens and maintain this critical antibiotic.