Isolation, identification and some characteristics of two lytic bacteriophages against Salmonella enterica serovar Paratyphi B and Salmonella enterica serovar Typhimurium from various food sources

FEMS Microbiol Lett. 2021 Apr 8:fnab037. doi: 10.1093/femsle/fnab037. Online ahead of print.


Salmonellosis is an important worldwide food-borne disease. Increasing resistance to Salmonella spp. has been reported in recent years and now, the prevalence of multidrug resistant (MDR) Salmonella spp. is a worldwide problem. This necessitates alternative approaches like phage therapy. This study aimed to isolate bacteriophages specific for Salmonella enterica serovar Paratyphi B and Salmonella enterica serovar Typhimurium isolated from different sources (chicken meat, beef, and eggshells). The antibiotic resistance profiles of the bacteria were determined by phenotypic and genotypic methods. The prevalence of extended-spectrum β-lactamase genes was examined by PCR. Totally, 75% of the isolated Salmonella strains were resistant to tetracycline, while this was 70% for azithromycin. All of the isolates from beef were resistant to nalidixic acid. The most common ESBL genes among the isolates were blaSHV (15%) followed by blaTEM (10%) and blaCTX (5%). Two specific bacteriophages were isolated and characterized. The host range for vB_SparS-ui was Salmonella Paratyphi B, Salmonella enterica serovar Paratyphi A, and Salmonella enterica. This was Salmonella Typhimurium and Salmonella enterica serovar Enteritidis for vB_StyS-sam phage. The characteristics of the isolated phages indicate that they are proper candidates to be used to control some foodstuffs contaminations and also phage therapy of infected animals.

PMID:33830213 | DOI:10.1093/femsle/fnab037