Antibiotic susceptibility and genetic relatedness of Shigella species isolated from food and human stool samples in Qazvin, Iran

Abstract

Objective The aim of this study was to investigate the genetic relatedness and antimicrobial resistance among Shigella species isolated from food and stool samples. Using cross sectional study method, Shigella spp. were isolated from food and clinical samples using culture-based, biochemical and serological methods. Antimicrobial susceptibility and genetic relatedness among the isolates were evaluated using disk diffusion and RAPD-PCR methods respectively. Results The prevalence of Shigella spp. were 4.84 and 7.7% in food and stool samples respectively. All food isolates were Sh. sonnei. 91.42% of the Shigella stool isolates were Sh. sonnei. 62.5% of food isolates were resistant to tetracycline. 46.8, 50 and 65.8% of clinical isolates were resistant to imipenem, amikacin and azithromycin respectively. 50 and 85.7% of the food and clinical isolates respectively were MDR. Dendrogram generated by RAPD-PCR showed that the isolates from food and stool samples were categorized in a same group. Close genetic relatedness between MDR Shigella isolates from food and clinical samples indicate that foods can be considered as one of the main vehicles for transmission of MDR Shigella to human causing acute diseases. Survey of MDR Shigella among food and clinical samples is strongly suggested to be implemented.

Phylogenetic analysis and antibiotic resistance of Shigella sonnei isolates

“…This study found that resistance against trimethoprim-sulfamethoxazole, tetracycline, lineage III strains due to the acquisition of point mutations within the gyrA and parC genes (Hawkey, et al 2021, Phiri, et al 2021, Shad and Shad 2021. It is extremely important to monitor different S. sonnei lineages/sublineages and the antibiotic resistance profile of these strains as the new emerging threat to public health and global concern of food safety (Hawkey, et al 2021, Pakbin, et al 2021a, Pakbin, et al 2021c.…”

“…to Shigella and Enterobacteriaceae family (Pakbin, et al 2021c, Torraca, et al 2020. S. sonnei has been regarded as the main cause of shigellosis in developed countries in North America and Europe.…”

“…The genotypic profile of S. sonnei isolates is strongly associated with the pathogenicity, resistance against different antibiotics, regional epidemiology and population structure of the pathogen (Pakbin, et al 2021b, Pakbin, et al 2021c. Consequently, genotype characterization of S. sonnei isolates helps to better investigate the outbreaks in respect of the presence of this pathogen and choose the most efficient strategies to prevent the spread of shigellosis due to the S. sonnei isolates.…”

Virulence Factors of Enteric Pathogenic Escherichia coli: A Review

“…Thus, they may be categorized in a single pathovar. However, a considerable distinction is still maintained regarding the clinical significance of Shigella species [1,73]. EIEC and Shigella are unable to ferment lactose, are non-motile, and lysine decarboxylase negative.…”

“…EIEC differs from other pathovars of E. coli because it is an obligate intracellular pathogen with neither adherence nor flagella factors [71]. Shigella comprise four species, including S. sonnei, S. flexneri, S. boydii and S. dysenteriae, which are responsible for varying degrees of diarrhea and acute intestinal and extra-intestinal diseases in humans [73,75,76]. EIEC strains primarily elicit watery diarrhea and cause invasive inflammatory colitis [77].…”