This study investigated genotypic and phenotypic antimicrobial resistance profiles, phylogenic relatedness, plasmid and virulence composition of 39 Salmonella enterica strains isolated from chicken meat samples using whole genome sequencing (WGS) technology. Four distinct serotypes were identified; Salmonella Minnesota (16/39, 41%), Salmonella Infantis (13/39, 33.3%), Salmonella Enteritidis (9/39, 23.1%), and one isolate was detected for Salmonella Kentucky (1/39, 2.6%), with sequence types (STs) as followed: ST548, ST32, ST11, and ST198, respectively. Phenotypic resistance to tetracycline (91.2%), ampicillin (82.4%), sulfisoxazole (64.7%), and nalidixic acid (61.6%) was the most observed. Resistome analysis revealed the presence of resistance genes to aminoglycosides, β-lactamase, sulfonamides, trimethoprim, phenicol, lincosamide, macrolides, and tetracyclines. Plasmidome showed the presence of eight incompatibility groups, including IncA/C2, IncFIB(K)_1_Kpn3, Col440I_1, IncR, IncX1, IncI1_1_Alpha, IncFIB(S)/IncFII(S), IncHI2/IncHI2A, IncX2 and ColpVC plasmids across the 39 genomes. Three resistance genes, sul2, tetA and blaCMY-2, were predicted to be located on IncA/C2 plasmid in S. Minnesota isolates, whereas all S. Infantis isolates were positive to IncFIB(K)_1_Kpn3 plasmid that carries blaCTX-M-65 gene. Eleven Salmonella pathogenicity islands and up to 131 stress and/or virulence genes were identified in the evaluated genomes. Phylogenetic analysis showed four phylogroups that were consistent with the identified ST profiles with a high level of inter-diversity between isolates. This is the first genomic characterization of Salmonella isolates from retail chicken meat in Saudi Arabia using WGS technology. The availability of Salmonella genomes from multiple geographic locations, including Saudi Arabia, would be highly beneficial in future source-tracking, especially during epidemiological surveillance and outbreak investigations.

The recent emergence and dissemination of mobilized colistin resistance ( mcr ) genes have triggered extensive concerns globally. Here, we report the complete genome sequence of a colistin-susceptible Salmonella enterica serotype Minnesota strain (named SA18578), belonging to sequence type 548 (ST548) and carrying the mcr-9 gene on an IncHI2/IncHI2A plasmid, that was isolated from chicken meat in Saudi Arabia in 2020.

Background: Antimicrobials dispensing without a prescription is recognized as a pathway for the emergence of antimicrobial resistance; a serious global public health issue in need of urgent regulatory responses. In mid-2018, the Saudi Ministry of Health initiated a nationwide antimicrobial restriction policy, in which pharmacies are strictlyprohibited from dispensing antimicrobial drugs without physicians’ prescription. Therefore, the objective of this study was to determine if this restriction policy implemented by the Saudi Ministry of Health has led to decrease in antimicrobial drugs sales. Methods: The annual retail sales information of antimicrobials was obtained from the pharmaceutical database, IQVIA-Multinational Integrated Data Analysis System (IQVIA-MIDAS®) between 2017 and 2019 to compare sales before and after the intervention. Antimicrobial drugs include the following: antibiotics; antifungals; antimycobacterials; combinations and other drugs. Nonparametric Wilcoxon Signed Rank test was used to assess changes in antimicrobials sales from pre- to post- intervention periods. Results: Our results showed that this intervention policy has achieved significate effects in reducing total antimicrobials sales by 23.2% from 818,916,437 SAR in 2017 to 648,383,630 SAR in 2019. Wilcoxon Signed Rank test showed a statistically significant median decrease in total antimicrobials sales after the intervention with a p-value = 0.0397. Reduction in the antibiotic amoxicillin was responsible for most of the decrease in antimicrobials sales with 70% less in 2019 compared to 2017. On the contrary, continuous increase in sales of some antimicrobial drugs following the restriction policy was observed led by the antibiotic amoxicillin/clavulanic acid. Conclusion: Our data support the implementation of antimicrobials restriction measures as an effective means of controlling excessive antimicrobials sales and dispensing without prescriptions.