Psychrotrophic properties, toxigenic characteristics, and PFGE profiles of Bacillus cereus isolated from different foods and spices

Hayriye Yeşim Can,Mehmet Elmalı,Alper Karagöz,Hüseyin Burak Dişli

doi:10.1590/0103-8478cr20210166

Hayriye Yeşim Can, Mehmet Elmalı + Show 2 more

Open Access

https://doi.org/10.1590/0103-8478cr20210166

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Journal: Ciência Rural	Publication Date: Jan 1, 2022
Citations: 2	License type: CC BY 4.0

Affiliation: Mustafa Kemal University, Usak University

Abstract

ABSTRACT: Bacillus cereus is an aerobic and facultatively anaerobic, spore-forming bacterium, and it is found naturally in soil and poses a risk factor for the contamination of food and foodstuffs including cereals, vegetables, spices, ready-to-eat (RTE) foods, meats, milk, and dairy products. This study determined the prevalence of B. cereus in raw poultry meat, raw cow’s milk, cheese, spices, and RTE foods in Hatay province. The study also analysed the psychrotrophic properties, toxigenic characteristics, and pulsed-field gel electrophoresis (PFGE) profiles of the isolates. The levels of contamination with B. cereus determined for cheese, raw milk, RTE foods, spices, and raw poultry meat were 16.6%, 34.2%, 42.8%, 49%, and 55.5%, respectively. B. cereus was isolated from 84 (42%) of the 200 samples analysed and the 84 isolates were verified by PCR analysis targeting the haemolysin gene specific for B. cereus. Of the total isolates, 64 (76.1%) were psychrotrophic. The toxin gene profiling of B. cereus isolates was determined by amplifying the four genes nhe, hbl, cytK, and ces. The nhe and cytK genes were most frequently detected in the isolates, while the hbl and ces genes were not found. In addition, a high genetic relationship between the isolates was detected at a 92% similarity level by PFGE analysis. In conclusion, the occurrence of both psychrotrophic and toxigenic B. cereus strains in this study indicated a potential risk for food spoilage and food poisoning.

Highlights

Bacillus cereus is one of the major foodborne pathogenic bacteria that causes two types of food poisoning
Diarrhoea is associated with some enterotoxins, the haemolysin BL (HBL), the non-haemolytic enterotoxin (NHE), and the cytotoxin K (CYTK)
Psychrotrophic property analysis To detect the psychrotrophic properties of B. cereus, all isolates were subcultured in BrainHeart Infusion broth and incubated for 24 h at 30 oC

Summary

INTRODUCTION

Bacillus cereus is one of the major foodborne pathogenic bacteria that causes two types of food poisoning. There are reports that the enterotoxin genes are more commonly found in B. cereus strains than the emetic gene (Granum & LUND, 1997; Stenfors Arnesen et al, 2008; HARIRAM & LABBE, 2015; Tewari et al, 2015; Owusu-Kwarteng et al, 2017; FOGELE et al, 2018; Gao et al, 2018; Berthold-PLUTA et al, 2019; Sánchez-Chica et al, 2020b). B. cereus has been isolated from different kinds of foods and foodstuffs such as meats, milk and dairy products, fish and seafood products, rice, starch, flours, spices and herbs, vegetables, ready-to-eat (RTE) foods, powdered foods (infant formula, powdered milk), and pastry (Wijnands et al, 2006; Park et al, 2009; Cadırcı et al, 2013; HARIRAM & LABBE, 2015; Tewari et al, 2015; Owusu-Kwarteng et al, 2017; Yıbar et al, 2017; FOGELE et al, 2018; Gao et al, 2018; Gdoura-Ben Amor et al, 2018; Osman et al, 2018; Berthold-Pluta et al, 2019; Adame-Gómez et al, 2020; SánchezChica et al, 2020a; Sánchez-Chica et al, 2020b). PFGE analysis was carried out to evaluate the genetic relatedness of isolates

MATERIALS AND METHODS

RESULTS AND DISCUSSION

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CONCLUSION