Characterization of non-typhoidal Salmonella associated with gastroenteritis in Eastern Province of Saudi Arabia

Abstract

Background and Objective: Urinary tract infections (UTIs) are a common cause of serious public health problems, with UroPathogenic Escherichia coli (UPEC) being the predominant etiological agent in both community and healthcare settings. UPEC isolates exhibit a wide range of virulence factors (VFs), which enhance their virulence potential in establishing primary, recurring and chronic UTIs. Antibiotic resistance to UPEC is increasingly being reported, worldwide. The aim of this study was to undertake molecular characterization of the UPEC isolates and correlate the expression of specific virulence-associated factor genes (VFGs) with multi-drug antibiotic resistance from hospital settings in King Fahad Hospital of the University (KFHU) in AL-Khobar, an Eastern Province in the Kingdom of Saudi Arabia. Material and Methods: A total of 182 urine samples positive for UPEC isolates were collected from different patients between 1st October 2016 and 30th April 2017 and the identification confirmed with VITEK 2 system. All UPEC isolates were tested for extended spectrum beta-lactamase (ESBL)-production and antibiotic susceptibility against a total of 17 antibiotics using VITEK 2 system. Then all UPEC isolates were screened for VFGs using polymerase chain reaction (PCR) technique, where genotyping was performed using gene-specific primers against the different VFGs (fimH, papC, sfa/focDEh, hlyCA, Usp, and iucC). Plasmid DNA extraction was processed using centrifugation method. Statistical analysis of the data was performed using SPSS software. Results: Majority of UPEC isolates were from female (71.20%) than male patients with UTIs. On analysis of the VFGs, the majority of UPEC isolates (94.51%) expressed fimH gene followed by usp (65.38%), papC (58.24%), hlyCA (29.67%), sfa/focDEh (29.67%), and iucC (17.58%), with no statistically significant gender difference (p>0.05). About 28.18% of the UPEC isolates were ESBL-producers. The isolates were highly resistant against amoxicillin (66.67%), ampicillin (65.05%) and amoxicillin/clavulanic acid (45%); and highly sensitive to tigecycline, nitrofurantoin and sulfamethoxazole (0% resistant). Antibiotic resistance was significantly associated with SfafocDEh (47%), iucC (47%), usp (35.29%), HlyCA (29.41%), and papC (23.5%) genes (p<0.05), but not fimH. However, fimH gene was significantly associated with UPEC resistance to amoxicillin/clavulanic acid (p=0.018). Conclusion: Findings from this study indicate that all the six VFGs are important for the pathogenicity of UPEC isolates. The fimH gene, which is ubiquitous in both E. coli commensals and UPEC strains, is poorly associated with antibiotic resistance of UPEC isolates. All the VFGs except the fimH gene are associated with antibiotic resistance. ESBL-production is a strong predictor of antibiotic resistance in nearly all classes of antibiotics. These findings necessitate revamped surveillance programs for resistant UPEC isolates and a review of antibiotic prescribing practices in Saudi Arabia. These would put to an end, the random prescription policies involving the classes of the antibiotics evaluated in this study.