Extensive Drug-Resistant Salmonella enterica Isolated From Poultry and Humans: Prevalence and Molecular Determinants Behind the Co-resistance to Ciprofloxacin and Tigecycline

Abstract

The emergence of extensive drug-resistant (XDR) Salmonella in livestock animals especially in poultry represents a serious public health and therapeutic challenge. Despite the wealth of information available on Salmonella resistance to various antimicrobials, there have been limited data on the genetic determinants of XDR Salmonella exhibiting co-resistance to ciprofloxacin (CIP) and tigecycline (TIG). This study aimed to determine the prevalence and serotype diversity of XDR Salmonella in poultry flocks and contact workers and to elucidate the genetic determinants involved in the co-resistance to CIP and TIG. Herein, 115 Salmonella enterica isolates of 35 serotypes were identified from sampled poultry (100/1210, 8.26%) and humans (15/375, 4.00%), with the most frequent serotype being Salmonella Typhimurium (26.96%). Twenty-nine (25.22%) Salmonella enterica isolates exhibited XDR patterns; 25 out of them (86.21%) showed CIP/TIG co-resistance. Exposure of CIP- and TIG-resistant isolates to the carbonyl cyanide 3-chlorophenylhydrazone (CCCP) efflux pump inhibitor resulted in an obvious reduction in their minimum inhibitory concentrations (MICs) values and restored the susceptibility to CIP and TIG in 17.24% (5/29) and 92% (23/25) of the isolates, respectively. Molecular analysis revealed that 89.66% of the isolates contained two to six plasmid-mediated quinolone resistance genes with the predominance of qepA gene (89.66%). Mutations in the gyrA gene were detected at codon S83 (34.62%) or D87 (30.77%) or both (34.62%) in 89.66% of XDR Salmonella. The tet(A) and tet(X4) genes were detected in 100% and 3.45% of the XDR isolates, respectively. Twelve TIG-resistant XDR Salmonella had point mutations at codons 120, 121, and 181 in the tet(A) interdomain loop region. All CIP and TIG co-resistant XDR Salmonella overexpressed ramA gene; 17 (68%) out of them harbored 4-bp deletion in the ramR binding region (T-288/A-285). However, four CIP/TIG co-resistant isolates overexpressed the oqxB gene. In conclusion, the emergence of XDR S. enterica exhibiting CIP/TIG co-resistance in poultry and humans with no previous exposure to TIG warrants an urgent need to reduce the unnecessary antimicrobial use in poultry farms in Egypt.

Whole-Genome Sequencing of Gram-Negative Bacteria Isolated From Bovine Mastitis and Raw Milk: The First Emergence of Colistin mcr-10 and Fosfomycin fosA5 Resistance Genes in Klebsiella pneumoniae in Middle East

“…The recent global dissemination of MDR and XDR Gram-negative bacteria has raised the alarm of antimicrobial resistance as a serious and an urgent threat to public health. Consequently, studies have been conducted to explore the distribution of several resistance genes in different reservoirs ( Tartor and El-Naenaeey, 2016 ; Elmowalid et al, 2018 ; Abd El-Aziz et al, 2021c ).…”

Antimicrobial resistance of Escherichia coli, Enterobacter spp., Klebsiella pneumoniae and Enterococcus spp. isolated from the feces of giant panda

“…Antimicrobials have been widely used to prevent and cure infectious diseases in captive giant pandas in recent decades [ 20 – 22 ]. However, with the widespread use of antimicrobials, the number of drug-resistant strains has increased and the development and spread of multidrug-resistant (MDR) bacteria in humans and the environment has accelerated [ 23 ]. In China, more antimicrobial agents are consumed than in most other countries.…”

Rapid Detection of Salmonella spp from Meat: Loop Mediated Isothermal Amplification (LAMP)

“…Therefore, identification and surveillance of Salmonella serotypes in humans and food animals especially poultry is essential to develop disease control measures. 4 In case of human infection, contamination of food is only the possible cause when these pathogens enter the food chain. Therefore, product and environmental monitoring for these pathogens are very important in order to reduce or prevent Salmonella illnesses/outbreaks from contaminated animal or human food.…”