Journal of Food Safety最新文献

This cross-sectional study determined the occurrence of virulence and antimicrobial resistance genes in Salmonella strains recovered from chicken obtained from informal markets in Gauteng province, South Africa. The study also assessed the relationship between these characteristics, the source, the type of samples, and the serotypes of Salmonella isolates. A total of 151 samples (cloacal swabs, chicken carcasses, and carcass drips) were randomly collected from 47 informal market outlets in six townships in Gauteng province. Salmonella spp. was isolated and identified based on ISO 6579:2002 methods and confirmed by polymerase chain reaction (PCR) targeting invA gene fragment. Conventional PCR was used to detect 12 virulence and 18 antimicrobial resistance (AMR) genes in Salmonella spp. The most frequently detected virulence genes were invA (100%), shdA (91%), mgtB (87.7%), and sopE (81%), but considerably low for spvC (2.2%), sefC (1.5%), and pefC (0.4%). The differences in detection frequency were statistically significant (p < 0.05). Tetracycline-resistant genes tetA (34.7%) and tetB (16%) were the most frequently detected, while Beta-lactam-resistant genes blaTEM (0.4%), blaCMY-2 (0.4%) and quinolones resistant gene qnrS (0.4%) were detected in low frequency (p < 0.05). The locations of the outlets and the types of samples were significantly associated with detecting some virulence and AMR genes. Significant but moderately to substantial positive correlations were observed for qnrS, sul2; shdA, and mgtB genes. The pipA and spiC were, however, substantially negatively correlated. Our findings show that detecting these virulence and AMR genes in Salmonella isolates serves as a potential health hazard to the public, environment, and poultry farming in Gauteng, South Africa.

Food contamination with plasmid-mediated antibiotic-resistant Escherichia coli has not been thoroughly investigated. This study aimed to clarify the prevalence of colistin-resistant AmpC/extended-spectrum β-lactamase (ESBL)-producing E. coli harbouring mcr (COL-ESBL-EC) and to determine antibiotic resistance by comparison with AmpC/ESBL-producing E. coli (ESBL-EC) and colistin-resistant E. coli harbouring mcr (COL-EC). Sixty chicken meats were tested for COL-ESBL-EC contamination. The result showed that 64 COL-ESBL-EC were isolated from 66.7% of the samples, and compared with ESBL-EC and COL-EC were isolated before. The genotypes of the COL-ESBL-EC showed bla_CTX-M-55/TEM, bla_CTX-M-55, bla_CMY-2, and bla_CTX-M-65 were predominant. The COL-ESBL-EC results showed a similar trend for bla_CTX-M identification to that of ESBL-EC. The mcr was investigated, and mcr-1 was detected in COL-ESBL-EC and COL-EC. Antibiotic susceptibility testing revealed that many strains of COL-ESBL-EC and ESBL-EC were resistant to quinolones, and fosfomycin (FOS). These results suggest that COL-ESBL-EC has simultaneously acquired AmpC/ESBL-related, quinolone, and FOS resistance genes in COL-EC.

The aim of this work was to evaluate the resistance of two pathogenic bacteria (Listeria monocytogenes and Salmonella enterica subsp. enterica serotype Senftenberg), and three airborne food-spoiling filamentous fungi (Hyphopichia burtonii, Penicillium nordicum, and Aspergillus brasiliensis ATCC 16404) to gaseous ozone on stainless steel. Tests were carried out by exposing inoculated tiles to gaseous ozone in a laboratorial chamber at concentrations up to 50 mg/L and at times up to 180 min (bacteria) or 300 min (filamentous fungi). For bacteria, the resistance to gaseous ozone of L. monocytogenes proved markedly higher than that of S. enterica. Their D-values increased by seven times (from 27.3 to 200.7 min for the strain of L. monocytogenes studied; from 7.3 to 48.0 min for the Salmonella species studied) when the ozone concentration were reduced from 12 to 4 mg/L. For filamentous fungi, a substantial effect was observed only at 50 mg/L on single-layered inocula: at these conditions, A. brasiliensis ATCC 16404 proved the most resistant strain to gaseous ozone, its D-value (134.4 min) being higher than those registered for the tested strains of H. burtonii (9.9 min) and P. nordicum (17.1 min). The results demonstrated that the use of gaseous ozone as a sanitizing agent for environments and working surfaces seems to be a potential alternative to chemical sanitizers against the two pathogens studied, whereas it seemed effective against the three filamentous fungi studied only in limited circumstances.

The laboratory inoculation techniques should ideally mimic the real-life environment to reliably estimate the decimal reduction time (D-value) of bacteria for process validation. This study aims at investigating the influence of the inoculation method on the D-value of Salmonella in black pepper powder. Whole black peppercorns were either inoculated prior to grinding (pre-grinding procedure) or ground and then inoculated (post-grinding procedure). The ground black pepper was thermaly treated at 80°C for 0-30 min. The D80°C values of Salmonella inoculated by pre-grinding and post-grinding procedures were 5.5 ± 0.8 and 3.9± 0.3, respectively. Salmonella and E. faecium were significantly (p⟨0.05) more thermally resistant in ground black pepper when inoculated pre- rather than post-grinding. Therefore, inoculation protocol must be considered by spice industries while validating the pasteurization process. E. faecium is a suitable surrogate for Salmonella because of its higher decimal reduction time for both inoculation methods.

This study investigated the impact of incorporating gas [air, carbon dioxide (CO₂), and nitrogen (N₂)] UFB on the potency of chlorine (Cl₂; 50, 100, and 200 ppm) and peracetic acid (PAA; 20, 40, and 80 ppm) antimicrobial (AM) solutions against fresh (3 days) and aged (30 days) E. coli O157:H7 biofilms on polypropylene, silicone, and stainless-steel surfaces. The biofilms were statically grown on polypropylene, silicone, and stainless-steel coupons (7.62 × 2.54 cm) at 25°C for 3 or 30 days by immersing in a 3-strain cocktail of E. coli. The incorporation of air, CO₂, and N₂ UFB in AM solutions resulted in significantly increased log reductions (2.1–3.7 logs) in fresh and aged E. coli biofilms on all surfaces compared to solutions without UFB, except for N₂ UFB on aged stainless-steel biofilms and air UFB on aged polypropylene biofilms, which resulted in similar log reductions as solutions without UFB (1.5–2.1 logs).

This study was conducted to encapsulate the bacteriophage SE-P47 target to Salmonella Enteritidis by extrusion method and to examine its stability. Screening and optimization of effective factors in the encapsulation process were performed using fractional factorial design and face-centered central composite design, respectively. The optimum Na-alginate concentration and the ratio of coating material to phage for the encapsulation of SE-P47 phage were 1.5% (v/v) and 2:1, respectively. At the optimum encapsulation point, the highest encapsulation efficiency (98.52%), smallest capsule size (1.28 mm), and highest phage titer were achieved. When exposed to heat treatment at 80°C for 30 min, pH 2 and simulated gastric fluid (pH 2.0) for 120 min, the encapsulated phage maintained almost its stability, but the free (non-encapsulated) phage almost lost its activity. Phage release from beads in simulated intestinal fluid reached 100% in 4 h. In addition, free and encapsulated phage completely maintained their activity for 12 months at 4 and 25°C. The Salmonella phage encapsulated in this study exhibits high stability in harsh conditions. Thus, this encapsulated phage has the potential to be used as a biocontrol agent or therapeutic purposes in the food chain.

Campylobacter jejuni is the predominant bacterial cause of gastroenteritis, the main cause of foodborne deaths. Currently, Campylobacter is a common foodborne pathogen found in poultry; thus, there is a need for the development of novel intervention strategies. The aim of the study was to examine the effect of eugenol on C. jejuni load in an experimental chicken meat model. We observed that eugenol was effective in reducing C. jejuni load for 7 days of storage. Eugenol treatment at all concentrations (1.28, 5.12, and 10.24 mg mL⁻¹) decreased Campylobacter load more significantly in the reference strain, and this decrease was dose-dependent throughout the storage period. Compared to the control group, eugenol reduced the counts of chicken isolate and the reference strain of C. jejuni by approximately 1.5 and 4.5 log/CFU, respectively, after 7 days of storage. Eugenol is a promising agent for improving the safety of poultry.

The microbial diversity of rose jam was analyzed by high-throughput sequencing, along with functional prediction of the bacterial community. The results indicate that Pseudomonas, Pantoea, and Burkholderia emerged were the top three dominant bacterial groups. Proteobacteria was particularly abundant in R4 (99.1%) and R6 (96.12%). Zygosaccharomyces, unclassified fungi, and Botrytis constituted the top three fungal groups. The presence of unclassified OTUs was observed in all samples, particularly in R6 (52.36%), R8 (45.28), and R9 samples (39.57%). Gene prediction using PICRUSt revealed the existence of multiple KEGG functional modules associated with human metabolism in each rose jam sample. The presence of a high abundance of functional genes indicated the microbial community's diverse wide range of microgenetic resources that can be further explored for research purposes. The microbial community found in rose jam exhibits remarkable diversity and encompasses valuable functional information relevant to human health.

Globally, the risk of foodborne diseases is high among the young, old, pregnant and immunocompromised groups. Strategies to improve safe food supply are poorly understood among stakeholders. In this paper, we discuss the importance of the adoption of food safety standards, the effects of non-compliance of food safety protocols, consumer-producer awareness of food safety, and the challenges involved in the adoption of food safety protocols. The major challenges include gaps in dissemination of relevant information, the cost involved in adoption of many food safety programs; low educational levels of food handlers, insufficient food testing laboratories; inadequate funding, equipment, and skilled personnel; and cost of training and education; and lack of coordination among organizations handling food safety issues. Building competencies of food safety personnel, inspectorates, national or regional laboratories and adequate resource support to industry and supporting agencies will enhance safety of the global food supply.

Foodborne pathogens can cause gastrointestinal infections in consumers and in some cases can even lead to outbreaks. In the last decade, it has been observed that some zoonotic pathogenic bacteria can use plants as secondary hosts. Contamination with foodborne bacteria becomes relevant in foods that are regularly eaten raw, such as lettuce, cilantro, fenugreek, rocket leaves, basil, and so forth, and some fruits such as tomatoes, melons, and green peppers; because the elimination of these pathogenic bacteria is difficult to achieve with conventional sanitization processes. Contamination of produce can occur throughout the entire production chain. In farmlands, pathogenic bacteria can contaminate the seed, mainly when contaminated water is used for irrigation. Later, bacteria can reach other plant tissues such as the stems, leaves, and fruits. Another form of contamination is when the produce is in contact with feces from domestic, production, or wild animals. Additionally, poor handling practices during harvest, packaging, distribution, and sale can contaminate produce. Studies have shown that foodborne pathogens can adhere to produce, sometimes forming a biofilm, and can also be internalized into the plant or fruit, which protects them from sanitation processes. For this reason, in this text we address three biocontrol strategies such as bacteria, lytic bacteriophages, and some fungi, as an alternative approach for the control of both foodborne and plant pathogens. Additionally, the use of these biological agents can represent an advantage for the development of the plant, making them a good strategy to favor yield.