Non-Typhoidal Salmonella in poultry meat and diarrhoeic patients: prevalence, antibiogram, virulotyping, molecular detection and sequencing of class I integrons in multidrug resistant strains

Abstract

BackgroundThe worldwide increase of food-borne infections with antibiotic resistant pathogens constitutes a major public health problem. Therefore, this study aimed to determine the prevalence, antibiogram, virulence genes profiles and integron characteristics of non-typhoidal Salmonella spp. isolated from poultry meat and diarrhoeic patients in Egypt.MethodsA total of 150 samples comprising (100 poultry meat and 50 diarrhoeic patients’ stool) were examined for the presence of Salmonella spp. using culture methods followed by biochemical and serological identification of the isolates. All Salmonella strains were tested for their susceptibility to the antibiotics using disk diffusion method and screened for the presence of virulence genes and class I integrons using PCR.ResultsThe overall prevalence of Salmonella spp. in poultry meat samples was 10 % compared to 4 % in diarrhoeic patients. All the isolates were serologically identified into Salmonella Typhimurium (seven isolates), S. Derby, S. Kiel, S. Rubislaw (one isolate, each) and untypable strains (two isolates). Antibiotic susceptibility testing showed a higher resistance of the total isolates to erythromycin and tetracycline (100 %, each), followed by amoxicillin-clavulanic acid (91.7 %), trimethoprim-sulfamethoxazole (83.3 %), streptomycin, nalidixic acid, ampicillin-sulbactam (75 %, each), gentamycin, ampicillin (66.7 %, each), chloramphenicol (58.3 %), ciprofloxacin (25 %) and ceftriaxone (16.7 %). Virulence genes profiles revealed the presence of sopB gene in five Salmonella strains isolated from poultry meat (n = 3) and humans (n = 2). Moreover, pefA was only identified in three isolates from poultry meat. On the other hand, S. Kiel and S. Typhimurium (one isolate, each) were harboring hilA and stn genes, respectively. Class 1 integrons were detected in all Salmonella spp. with variable amplicon sizes ranged from 650–3000 bp. Sequencing of these amplicons revealed the presence of gene cassettes harboring aac(3)-Id, aadA2, aadA4, aadA7, sat, dfrA15, lnuF and estX resistance genes. Nucleotide sequence analysis showed point mutations in the aac(3)-Id of S. Derby, aadA2, estX-sat genes of S. Typhimurium. Meanwhile, frame shift mutation was observed in aadA7 genes of S. Typhimurium.ConclusionsIncreasing rate of antimicrobial resistance and class 1 integrons among multidrug resistant Salmonella spp. has prompted calls for the reduction of antimicrobial use in livestock to prevent future emergence of resistance.

Serological identification and antimicrobial resistance of Salmonella isolates from broiler carcasses and human stools in Beni-Suef, Egypt

“…They were much higher than that previously reported by Gharieb et al (2015) in Egypt, who detected Salmonella spp. with a prevalence of 14% in chicken meat.…”

“…with a percentage of 4%. In this regard, Gharieb et al (2015) reported a similar prevalence (4%) of Salmonella in human stools in Egypt. Moreover, Murugkar et al (2005) reported nearly similar prevalence in India.…”

Dynamics of Salmonella Shedding and Welfare of Hens in Free-Range Egg Production Systems

“…The detection of these genes by PCR has been widely used as a predictive measure for Salmonella virulence (32,33). sptP was not amplified among S. Mbandaka and Worthington isolates.…”

An Algerian perspective on non-typhoidal Salmonella infection

“…NTS cause a gastrointestinal infection which presents as inflammation manifested with diarrhea, nausea, vomiting, and headache [13]. The severity of infection varies depending on two factors; the serotype implicated and the health of the patient [14].…”

“…An Egyptian study conducted on Salmonella isolates from human and animals showed an increasing rate of antimicrobial resistance among NTS isolates between 2014 and 2015, in particular to erythromycin and tetracycline, and amoxicillin-clavulanic acid. This resistance was linked to over-use of antimicrobials in livestock [13]. In Kenya, among 342 NTS isolates, the prevalence of MDR strains reached 42% during 2003 [47].…”