Prevalence of Salmonella spp. in Egyptian dairy products: molecular, antimicrobial profiles and a reduction trial using d-tryptophan

Critical occurrence of verotoxgenic <em>E.coli</em> and non-typhoidal <em>salmonella<em> in some heat treated dairy products

“…It is worth noting that other investigated dairy products in Mansoura city were in harmony with our finding, where S. Typhimurium and S. Infantis were observed in 4% of soft cheese and Kareish cheese by El-Baz et al (2017) and recently three isolates of S. Typhimurium were isolated from Kareish cheese by Elafify et al (2019). To author knowledge, this is the first study reporting the isolation of very rare S. Essen serotype from the milk-based product as it commonly isolated only from retail food and chicken meat (Menghistu et al, 2011;Wang et al, 2015) and was of public health importance for both human and veterinary medicine.…”

“…depends mainly on the presence of the genetic determinants responsible for their virulence (Rhen et al, 2007;Saini et al, 2019). In the current study, PCR based assay proves the ability of isolated S. Typhimurium and S. Infantis to invade, destroy, escape from macrophage and colonize host intestinal cell inducing various lesions and gastrointestinal signs if consumed within infected dairy products as they were positive for invA, stn and spvC virulence genes (Table 3, Figure 2) which were also identified previously by El-Baz et al (2017), Omar et al (2018) and Elafify et al (2019) in the same serotypes but in other conventional milk products. Astonishingly, PCR screening in our work confirmed that S. Essen serotype poses infection risks to humans as despite being negative for spvC virulence gene which responsible for systemic infection, it was positive for invA and stn virulence genes which are mandatory for Salmonella enterotoxigenic potency in inducing humans gastroenteritis.…”

“…( 2017 ) and recently three isolates of S. Typhimurium were isolated from Kareish cheese by Elafify et al . ( 2019 ). To author knowledge, this is the first study reporting the isolation of very rare S. Essen serotype from the milk-based product as it commonly isolated only from retail food and chicken meat (Menghistu et al ., 2011 ; Wang et al , 2015 ) and was of public health importance for both human and veterinary medicine.…”

“…( 2018 ) and Elafify et al . ( 2019 ) in the same serotypes but in other conventional milk products. Astonishingly, PCR screening in our work confirmed that S. Essen serotype poses infection risks to humans as despite being negative for spvC virulence gene which responsible for systemic infection, it was positive for invA and stn virulence genes which are mandatory for Salmonella enterotoxigenic potency in inducing humans gastroenteritis.…”

“…Based on the method explained by Elafify et al . ( 2019 ), each sample was tenfold diluted (10 -1 ) using buffered peptone water and then incubated at 37°C for one day. Then, 1ml of each diluted sample was transferred to 10 ml of Rappaport and Vassilidis enrichment broth followed by overnight incubation at 42°C.…”