title: Prevalence, serotyping and antimicrobials resistance mechanism of Salmonella enterica isolated from clinical and environmental samples in Saudi Arabia.
abstract: Salmonella is recognized as a common foodborne pathogen, causing major health problems in Saudi Arabia. Herein, we report epidemiology, antimicrobial susceptibility and the genetic basis of resistance among S. enterica strains isolated in Saudi Arabia. Isolation of Salmonella spp. from clinical and environmental samples resulted in isolation of 33 strains identified as S. enterica based on their biochemical characteristics and 16S-rDNA sequences. S. enterica serovar Enteritidis showed highest prevalence (39.4%), followed by S. Paratyphi (21.2%), S. Typhimurium (15.2%), S. Typhi and S. Arizona (12.1%), respectively. Most isolates were resistant to 1st and 2nd generation cephalosporin; and aminoglycosides. Moreover, several S. enterica isolates exhibited resistance to the first-line antibiotics used for Salmonellosis treatment including ampicillin, trimethoprim-sulfamethoxazole and chloramphenicol. In addition, the results revealed the emergence of two S. enterica isolates showing resistance to third-generation cephalosporin. Analysis of resistance determinants in S. enterica strains (n=33) revealed that the resistance to β-lactam antibiotics, trimethoprim-sulfamethoxazole, chloramphenicol, and tetracycline, was attributed to the presence of carb-like, dfrA1, floR, tetA gene, respectively. On the other hand, fluoroquinolone resistance was related to the presence of mutations in gyrA and parC genes. These findings improve the information about foodborne Salmonella in Saudi Arabia, alarming the emergence of multi-drug resistant S. enterica strains, and provide useful data about the resistance mechanisms.
authors.affiliation: King Saud University, College of Science, Department of Botany and Microbiology, Riyadh, Saudi Arabia.
authors.forename: Mohamed A
authors.initials: MA
authors.lastname: El-Tayeb
authors.affiliation: King Saud University, College of Science, Department of Botany and Microbiology, Riyadh, Saudi Arabia; National Research Center, Pharmaceutical Industries Research Division, Department of Chemistry of Natural and Microbial Products, Cairo, Egypt. Electronic address: ashebl@ksu.edu.sa.
authors.forename: Abdelnasser S S
authors.initials: ASS
authors.lastname: Ibrahim
authors.affiliation: King Saud University, College of Science, Department of Botany and Microbiology, Riyadh, Saudi Arabia.
authors.forename: Ali A
authors.initials: AA
authors.lastname: Al-Salamah
authors.affiliation: King Saud University, College of Science, Department of Botany and Microbiology, Riyadh, Saudi Arabia.
authors.forename: Khalid S
authors.initials: KS
authors.lastname: Almaary
authors.affiliation: King Saud University, College of Science, Department of Botany and Microbiology, Riyadh, Saudi Arabia.
authors.forename: Yahya B
authors.initials: YB
authors.lastname: Elbadawi
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D024901:Drug Resistance, Multiple, Bacterial; D004783:Environmental Microbiology; D006801:Humans; D032023:Integrons; D008826:Microbial Sensitivity Tests; D012480:Salmonella Infections / Q000382:microbiology*; D019779:Salmonella enterica / Q000145:classification / Q000187:drug effects* / Q000235:genetics / Q000302:isolation & purification*; D012529:Saudi Arabia; D012703:Serotyping; D013752:Tetracycline / Q000494:pharmacology
chemical_list: D000900:Anti-Bacterial Agents; D013752:Tetracycline
keywords: Antibiotic resistance; Antimicrobials resistance determinants; Salmonella; Serotyping