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

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.

Consumers Awareness of the Message Not to Wash Raw Poultry, Current Practices, and Barriers to Following that Message

There are an estimated 47.8 million cases of foodborne illness in the U.S. each year. Raw poultry is the most common single commodity food associated with foodborne illness. The practice of washing raw poultry is highly prevalent among consumers despite the significant cross contamination risk. Previous educational campaigns have attempted to reduce the prevalence of washing raw poultry; however, there is limited information on how successful they have been in changing consumer behavior. In the research presented here, an online survey was administered to 1,822 consumers in the United States via SurveyMonkey. The survey sought to determine whether consumers washed raw poultry and if they were aware of the correct behavior to not wash raw poultry. Consumers who indicated that they were not aware of the correct behavior were presented with the USDA's educational message online and then asked how confident they were that they could stop washing raw poultry. The survey also included questions to identify barriers that prevented consumers who were aware of the correct behavior from not washing raw poultry. Results indicate that 73.5% (n = 1340) of consumers reported washing raw poultry. Of those consumers, 68.1% (n = 913) indicated that they were not aware that the practice is incorrect. When these consumers were presented the educational message, 81.9% (n =748) indicated that they were somewhat to very confident that they could stop washing raw poultry. Of the consumers who were aware of the correct behavior but continued to wash raw poultry, 58.4% (n = 244) reported that they continued to do so because they thought they cleaned surfaces well afterward. That is, consumers did not believe that their washing raw poultry was a risk for cross contamination. Data indicate that a large percentage of consumers are still not aware of the correct behavior to not wash raw poultry and a large subset of that group may easily adopt the practice if made aware of the correct behavior.

Understanding barriers to consumers to stop washing raw poultry through in-depth interviews

PurposeFoodborne illness from poultry may be associated with improper handling that results in cross contamination. Washing of raw poultry is one practice that can lead to cross contamination. Some consumers continue to wash raw poultry after learning that not washing raw poultry is the safe behavior. There is a need to better understand why some consumers continue this practice and identify barriers to them adopting the correct behavior.Design/methodology/approachThis research utilized qualitative, in-depth interviews to understand some consumer's barriers to adopting the behavior of not washing raw poultry. The interview questioning route was iteratively developed and designed to allow both structure and flexibility. Questions were anchored in the Transtheoretical Model of Behavior Change. Interviews (N = 23) were conducted over Zoom. Thematic analysis identified themes around consumers' resistance to adopting the correct behavior for handling raw poultry.FindingsResults from the thematic analysis indicate that chicken preparation methods were primarily influenced by family. A desire to control the process of preparing food, lack of trust in chicken processing, and the habitual nature of the behavior all contributed to the continuation of washing raw poultry. Over half of the participants (61%) expressed interest in changing behaviors in the future. Needing supporting scientific evidence, and an alternative behavior to replace washing were two key factors to support the development of future public health messaging.Originality/valueThis study investigates the barriers to safe raw poultry handling utilizing in-depth interviews and contributes to the development of more effective public health messaging.

The Prevalence and Epidemiology of Salmonella in Retail Raw Poultry Meat in China: A Systematic Review and Meta-Analysis

Foodborne disease caused by Salmonella is an important public health concern worldwide. Animal-based food, especially poultry meat, is the main source of human salmonellosis. The objective of this study was to evaluate the prevalence and epidemiology of Salmonella contamination in raw poultry meat commercialized in China. Following the principle of systematic review, 98 sets of prevalence data were extracted from 74 publications conducted in 21 Chinese provincial regions. The random-effect model was constructed for subgrouping analysis by meat category, preservation type, and geographical location. The prevalence levels differed from high to low among raw poultry meat, including chicken, 26.4% (95% CI: 22.4–30.8%); pigeon, 22.6% (95% CI: 18.2–27.8%); duck, 10.1% (95% CI: 5.3–18.2%); and other poultry meat, 15.4% (95% CI: 12.0–19.5%). Prevalence data on the preservation type revealed that chilled poultry meat might be more likely to experience cross-contamination than non-chilled poultry meat in China. The distribution map of Salmonella for raw poultry meat showed that a higher prevalence level was found in the Shaanxi, Henan, Sichuan, and Beijing regions. All subgroups possessed high amounts of heterogeneity (I2 > 75%). The scientific data regarding the differences in prevalence levels between meat category, preservation method, and geographical region sources might be useful to improve specific interventions to effectively control the incidence of Salmonella in poultry meat.

Differences in antimicrobial resistance of Salmonella spp. isolated from humans, animals and food products in Kazakhstan

The aims of this study were twofold: 1. to isolate Salmonella spp. from different sources in Kazakhstan, to determine their serovars and resistance profiles and 2. to evaluate similarities in antimicrobial susceptibility of Salmonella spp. isolated from humans, animals and food products. From the10 212 samples tested Salmonella spp. Were isolated in 47 cases. The predominant serovar isolated from humans and food products was S. Enteritidis. Although different animal species were tested the Salmonella spp. were isolated mainly from chickens and ducks. S. Enteritidis and S. Typhimurium were the most prevalent serovars in raw poultry meat. The most frequent resistances were those to nalidixic acid, ampicillin and tetracycline. Human isolates demonstrated lower resistance compared to animal and food isolates. The genes encoding antimicrobial resistance in human isolates in most cases were absent except for some isolates which harboured tet, sul, stre and bla TEM genes encoding resistance to the oldest antimicrobial classes. The situation in animals and food products was less beneficial as besides different genes, integrons associated with the horizontal gene transfer were detected. The findings suggest that antimicrobials in animal sector should be used more strictly, paying attention to critically important antimicrobials for humans and possible horizontal transfer of pathogens and their genetic determinants.

Validation of a Commercial Loop-Mediated Isothermal Amplification (LAMP)-Based Kit for the Detection of Salmonella spp. According to ISO 16140:2016

The traditional cultural method (PCR and Real-Time PCR) for Salmonella spp. detection and identification is laborious and time-consuming. A qualitative LAMP method detecting Salmonella spp. was validated in compliance with ISO 16140:2016. The results show a relative accuracy, sensitivity, and specificity of 100% in comparison with the reference method ISO 6579-1:2017; the LOD50 was set as 0.4 CFU/g. Additionally, a field study was carried out comparing the LAMP kit, a commercially available Real-Time PCR kit (FoodProof Salmonella, Biotecon Diagnostics), and the reference cultural method. The Salmonella spp. LAMP kit was suitable for reliable detection of Salmonella spp., simplifying and reducing the extent and the steps of the analytical process. A total of 105 samples of raw poultry meat were screened for the presence of Salmonella spp. according to three methods: the LAMP kit Salmonella spp. (Enbiotech), the Real-Time PCR kit FoodProof Salmonella (Biotecon), and the reference cultural method. Using these three methods, only one sample out of the 105 (0.95%) tested was positive for Salmonella spp. This sample was further investigated using the reference method described in ISO 6579-3:2014, in order to characterise the Salmonella strain. Following this further biochemical identification and serological typing, the isolate was characterised as Salmonella Infantis.

Application of peroxyacetic acid for decontamination of raw poultry products and comparison to other commonly used chemical antimicrobial interventions – A Review

Poultry remains one of the top food commodities responsible for foodborne illness in the U.S., despite poultry industry efforts since the inception of HACCP to reduce the burden of foodborne illness implicating poultry products. The appropriate use of antimicrobial compounds during processing of raw poultry can help minimize this risk. Currently, peroxyacetic acid (PAA) is the most popular antimicrobial in the poultry industry, displacing chlorine compounds and others. The aim of this review was to compare the effectiveness of PAA to that of other antimicrobials for the decontamination of raw poultry carcasses and parts. Twenty-six articles were found that compared PAA to over 20 different antimicrobials, applied as spray or immersion treatments for different exposure times and concentrations. The most common comparisons were to chlorine compounds (17 articles), to lactic acid (LA) compounds (5 articles) and to cetylpyridinium chloride (CPC, 6 articles). Studies measured effectiveness by reductions in native flora or inoculated bacteria, usually Salmonella or Campylobacter . PAA was found to be more effective than chlorine under most conditions studied. Effectiveness of PAA was higher or comparable to that of LA and CPC depending on product and treatment conditions. Overall, the results of primary literature studies support the popularity of PAA as an effective intervention against pathogenic bacteria during poultry processing.

Cross-contamination of lettuce with Campylobacter spp. via cooking salt during handling raw poultry

Campylobacter spp. are the most common bacterial pathogens associated with human gastroenteritis in industrialized countries. Contaminated chicken is the food vehicle associated with the majority of reported cases of campylobacteriosis, either by the consumption of undercooked meat or via cross- contamination of ready-to-eat (RTE) foods during the handling of contaminated raw chicken parts and carcasses. Our results indicate that cooking salt (used for seasoning) is a potential vehicle for Campylobacter spp. cross-contamination from raw chicken to lettuce, through unwashed hands after handling contaminated chicken. Cross-contamination events were observed even when the chicken skin was contaminated with low levels of Campylobacter spp. (ca. 1.48 Log CFU/g). The pathogen was recovered from seasoned lettuce samples when raw chicken was contaminated with levels ≥ 2.34 Log CFU/g. We also demonstrated that, once introduced into cooking salt, Campylobacter spp. are able to survive in a culturable state up to 4 hours. After six hours, although not detected following an enrichment period in culture medium, intact cells were observed by transmission electron microscopy. These findings reveal a “novel” indirect cross-contamination route of Campylobacter in domestic settings, and a putative contamination source to RTE foods that are seasoned with salt, that might occur if basic food hygiene practices are not adopted by consumers when preparing and cooking poultry dishes.