Multiplex polymerase chain reaction detection of Shiga toxin genes and antibiotic sensitivity of Escherichia coli O157:H7 isolated from beef meat in Quetta, Pakistan

Abstract

The objective of this study was to conduct a qualitative analysis of raw beef meat sold in the city of Quetta, Pakistan for presence and drug sensitivity of the potentially pathogenic Escherichia coli strain O157:H7. The study used 200 raw beef meat samples collected from retail butcher shops. Conventional and rapid biochemical tests, latex agglutination and multiplex polymerase chain reaction (PCR) using primers designed for the rfb O157 and flic H7 genes were used to detect E. coli O157:H7. All O157:H7 isolates were also tested for Shiga toxin genes stx 1 and stx 2. The prevalence of E. coli O157:H7 in collected beef meat samples was 10%. Detection through PCR was found more sensitive than detection of O and H antigens. The quantity of E. coli O157:H7 isolates positive for Shiga toxins was 50% (20% for stx 1, 45% for stx 2 and 10% for both stx 1 and stx 2). Season wise variation showed highest E. coli O157:H7 prevalence during summer months. A further concern is that E. coli O157:H7 isolates were resistant to a range of common antibiotics. The results indicate an urgent need for applying proper food hygiene practices in the Quetta region to reduce incidence of foodborne diseases and they also emphasize the global problem of antimicrobial resistance. Practical applications E. coli O157:H7 is as a potentially threatening foodborne pathogen. A significant prevalence of E. coli O157:H7 detected in raw beef meat from retail outlets in the city of Quetta indicates an urgent need for applying proper food hygiene practices in the Quetta region to reduce the incidence of foodborne diseases. Furthermore, resistance of the E. coli O157:H7 isolates to a range of commonly used antibiotics emphasizes the global problem of antimicrobial resistance. The multiplex PCR method used here is a reliable, sensitive, and relatively rapid technique for detecting E. coli O157:H7 in food and environmental samples and important for ongoing surveillance to minimize contamination of raw meat products and associated cross contamination by E. coli O157:H7.

Prevalence and molecular characterization of multidrug‐resistant Escherichia coliO157: H7 from dairy milk in the Peshawar region of Pakistan

“…In our study, three of the O157: H7 isolates tested positive for both of the stx 1 and stx 2 genes, and three tested positive for only stx 2 . This observation is consistent with many other studies that have reported a higher detection of the stx 2 gene than the stx 1 gene in E. coli O157: H7 isolates (Samad, Abbas, Ahmad, Tanveer, et al, 2018). In 800 samples of chicken, beef meat, milk, and vegetables/salads from retail markets in Quetta, the total incidence of E. coli O157: H7 was 8%; in milk, the incidence was 4% from dairy farms and 12% from retail markets (Samad, Abbas, Ahmad, Pokryrshko, & Asmat, 2018).…”

“…Natural reservoirs of E. coli O157: H7 include cattle, sheep, and goats, and the modes of transmission of the infections are animal to person, waterborne, foodborne, and person to person (Samad, Abbas, Ahmad, Tanveer, et al, 2018;Abreham, Teklu, Cox, & Sisay Tessema, 2019;Ateba & Mbewe, 2011;Ferens & Hovde, 2011).…”

Contamination of ready-to-eat street food in Pakistan with Salmonella spp.: Implications for consumers and food safety

“…Although RTE food sold by street vendors is cheap in price, its microbial quality may be compromised if proper hygienic measures are not adopted. In developing countries such as Pakistan, such measures are often neglected, and food items have been reported to be contaminated with several pathogens (Samad et al, 2018a(Samad et al, , b, 2019(Samad et al, , 2020. The results of the present study are alarming, as none of the RTE food samples tested (n = 320) were free of bacteria.…”

Review of recent advances in improved lateral flow immunoassay for the detection of pathogenic Escherichia coli O157:H7 in foods

“…In the past decades, most attention have been directed toward the use of polymerase chain reaction (PCR) methods of DNA‐based technology. These include single and multiplex PCR with specific primer pairs (Samad et al, 2018), qualitatively real‐time PCR, and loop‐mediated isothermal amplification (LAMP) assays (Zhang et al, 2019) for the detection of E. coli O157:H7 (Liu, Singh, & Mustapha, 2018; Mahmoudzadeh et al, 2016; Suria, Adlin Azlina, Mohd Afendy, & Zamri, 2013). This PCR‐based method is one of the most sensitive and specific methods in routine diagnosis of STES E. coli O157:H7 in foods.…”