Occurrence and D-Tryptophan Application for Controlling the Growth of Multidrug-Resistant Non-O157 Shiga Toxin-Producing Escherichia coli in Dairy Products

Abstract

The objectives of the current study were first to determine the prevalence of non O157:H7E. coli, especially Shiga toxin-producing Escherichia coli (STEC) in retailed milk and dairy products in Egypt. Second, the antimicrobial resistance profiling and virulence genes of the isolated E. coli strains were screened. Third, evaluation of the inhibitory effects of D-tryptophan against E. coli O26:H11 was further performed. The results revealed that 20% (30/150) of the samples were STEC positive, with 64 isolates harboring some virulent genes, such as Stx1, Stx2, eaeA, and hylA. Serological identification revealed four different pathotypes belonging to EPEC, ETEC, EHEC, and EIEC. Antimicrobial susceptibility testing revealed that 100%, 98.44%, 92.19%, 71.87%, 65.63% and 64.06% of the isolates had a resistance against tetracycline, oxacillin, erythromycin, nalidixic acid, sulphamethoxazol, and ampicillin, respectively. D-tryptophan addition (40 mM) to E. coli O26:H11-inoculated soft cheese and ice cream revealed a significant reduction (p < 0.05) in bacterial growth, especially when accompanied with other food stressors. D-Tryptophan is considered as an effective food preservative and as a promising alternative candidate in the dairy industry.

D‐tryptophan, an eco‐friendly natural, safe, and healthy compound with antimicrobial activity against food‐borne pathogens: A systematic review

“…Although the mechanism of antimicrobial activity of D-tryptophan is still not well known, it appears that D-tryptophan reduces the initial adhesion of pathogenic cells and changes the characteristics of the extracellular environment, which have a significant effect on the weakening of pathogenic cells. D-tryptophan also prevents the formation of biofilms by using the same mechanism and acts as an autoinhibitory compound, which prevents the germination of spores and the growth of pathogens (Elafify et al, 2019(Elafify et al, , 2023Elafify, Sadoma, et al, 2022).…”

“…Despite the great advances in food technology, hospitalizations due to food‐borne pathogens are reported in approximately 300,000 people, which leads to 5000 deaths annually. In addition, its economic loss is estimated at 7 billion dollars; therefore, food safety departments, food experts, and regulatory organizations must pay special attention to this issue (Brandão et al., 2023 ; Elafify, Darwish, et al., 2022 ; Elafify, Sadoma, et al., 2022 ; Liu et al., 2019 ).…”

“…Therefore, the demand for healthy, natural, and high-quality processed foods is growing rapidly. One solution to reduce the use of chemical preservatives is to replace them with bio-preservatives (Elafify, Sadoma, et al, 2022;Mith et al, 2014;Moghimani et al, 2023;Mohan et al, 2021).…”

Prevalence of Shiga Toxin Producing Enterohemorrhagic Escherichia coli O157:H7 Isolated from Chicken Meat in Northern Punjab, Pakistan

“…STEC infection once has developed and is followed by HUS are unpreventable and diarrhea that is associated with HUS cannot be treated (Monet-Didailler et al, 2019). STEC strain infection transmission occurs commonly through direct/indirect contact, intake of food products specially through improperly cooked meat, vegetables, game meat, milk, dairy products (Elafify et al, 2022) and contaminated water with feces of carriers (Dias et al, 2022). The Stx2 is more harmer, and a mixture of both toxins in specific ratio is usually associated with Hemolytic uremic syndrome (Andreoli, 2022).…”

Engineering the Thermostability of a d-Carbamoylase Based on Ancestral Sequence Reconstruction for the Efficient Synthesis of d-Tryptophan

“…d -Tryptophan displays analgesic activity and can be used to prepare antibiotics, which are vital synthons for the synthesis of Tadalafil (cialis) and other related peptides − as well as Thymodepressin (γ- d -Glu- d -Trp) . In addition, d -tryptophan is considered as an effective food preservative and a promising substitute in the dairy industry . Considering their wide application and increasing demand, the development of efficient methods for the synthesis of d -amino acids has become a prospective field in the amino acid industry.…”