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Background: Dairy products are considered some important sources of various nutritional compounds; however, pathogenic bacterial growth is a critical destructive factor to these products leading to consumer health and system financial crises. Aim: The current study was carried out to identify if there is any presence of Staphylococcus aureus related enterotoxin genes in cheese samples. Methods: The research included the collection of 35 samples. The samples passed through conventional cultivation processes and a PCR method to detect the presence of icaA, sea, hla, and fnbA enterotoxin genes in these samples. Results: The conventional identification revealed the growth of S. aureus from the cheese samples. The PCR findings recorded the presence of the icaA, sea, hla, and fnbA in 31 (88.5%), 27 (77%), 19 (54%), and 12 (34%), respectively, of cheese samples. The sequencing revealed close similarities with global isolates, which reached up to 98.5% of identity. Conclusion: The current results indicate the presence of enterotoxin genes of Staphylococcus aureus in high rates in the dairy products examined, which reveals critical problems of food safety due to the possible presence of enterotoxins in consumer dairy products. [Open Vet J 2024; 14(8.000): 2073-2078]

Abstract Background Staphylococcus aureus (S. aureus) is one of the most widespread bacterial pathogens in animals and humans, and its role as an important causative agent of food poisoning is well-documented. The aim of this study was to highlight and characterize the resistance patterns of methicillin-resistant S. aureus (MRSA) in charcuterie products sold in selected supermarkets (SM) in Bobo-Dioulasso, Burkina Faso. Methods In this study, 72 samples including ham (n = 19), merguez (n = 22), sausage (n = 15) and minced meat (n = 16) were collected from 3 supermarkets. Standard microbiology methods were utilised to characterise S. aureus isolates. Phenotypic resistance patterns were investigated using the disk diffusion method on Mueller-Hinton agar. Genotypic testing using polymerase chain reaction (PCR) was performed on the isolates to detect the 16S-23S gene. Using specific primers, the following genes PVL, TSST-1, mecA, gyrA, gyrB, qnrA, intI1 and aac(6’)-Ib-cr were identified from purified DNA by PCR. Results Among the 72 ready-to-eat food samples, S. aureus was present in 51, (70.83%). The yield was highest in both the ham and merguez food products, 15/51 (29.41%) each, followed by minced meat 12/51 (23.53%) and sausage 9/51 (17.65%). A total of 35 isolates (68.63%) were confirmed as S. aureus after molecular characterization using 16–23 S primers with 05 (14.29%) strains identified as MRSA. All of the MRSA and majority of the methicillin-sensitive S. aureus (MSSA) isolates were resistant to penicillin G, ampicillin, tetracycline and erythromycin, whereas one isolate from minced meat was found in SM3-harbouring PVL, TSST-1, mecA, gyrA, gyrB and Int1 genes. Conclusions Our study revealed a high prevalence of S. aureus in chacuterie products in Bobo-Dioulasso with antimicrobial profiles that show resistance to most antibiotics. These findings should inform and augment efforts to raise awareness among local supermarket owners on adequate food manufacturing practices as well as promoting food safety and hygiene.

Background: Dairy products are considered some important sources of various nutritional compounds; however, pathogenic bacterial growth is a critical destructive factor to these products leading to consumer health and system financial crises. Aim: The current study was carried out to identify if there is any presence of Staphylococcus aureus-related enterotoxin genes in cheese samples. Methods: The research included the collection of 35 samples. The samples passed through conventional cultivation processes and a PCR method to detect the presence of icaA, sea, hla, and fnbA enterotoxin genes in these samples. Results: The conventional identification revealed the growth of S. aureus from the cheese samples. The PCR findings recorded the presence of the icaA, sea, hla, and fnbA in 31 (88.5%), 27 (77%), 19 (54%), and 12 (34%), respectively, of cheese samples. The sequencing revealed close similarities with global isolates, which reached up to 98.5% of identity. Conclusion: The current results indicate the presence of enterotoxin genes of S. aureus in high rates in the dairy products examined, which reveals critical problems of food safety due to the possible presence of enterotoxins in consumer dairy products. [ABSTRACT FROM AUTHOR]

Background: Staphylococcus aureus (S. aureus) is one of the most widespread bacterial pathogens in animals and humans, and its role as an important causative agent of food poisoning is well-documented. The aim of this study was to highlight and characterize the resistance patterns of methicillin-resistant S. aureus (MRSA) in charcuterie products sold in selected supermarkets (SM) in Bobo-Dioulasso, Burkina Faso. Methods: In this study, 72 samples including ham (n = 19), merguez (n = 22), sausage (n = 15) and minced meat (n = 16) were collected from 3 supermarkets. Standard microbiology methods were utilised to characterise S. aureus isolates. Phenotypic resistance patterns were investigated using the disk diffusion method on Mueller-Hinton agar. Genotypic testing using polymerase chain reaction (PCR) was performed on the isolates to detect the 16S-23S gene. Using specific primers, the following genes PVL, TSST-1, mecA, gyrA, gyrB, qnrA, intI1 and aac(6')-Ib-cr were identified from purified DNA by PCR. Results: Among the 72 ready-to-eat food samples, S. aureus was present in 51, (70.83%). The yield was highest in both the ham and merguez food products, 15/51 (29.41%) each, followed by minced meat 12/51 (23.53%) and sausage 9/51 (17.65%). A total of 35 isolates (68.63%) were confirmed as S. aureus after molecular characterization using 16–23 S primers with 05 (14.29%) strains identified as MRSA. All of the MRSA and majority of the methicillin-sensitive S.aureus (MSSA) isolates were resistant to penicillin G, ampicillin, tetracycline and erythromycin, whereas one isolate from minced meat was found in SM3-harbouring PVL, TSST-1, mecA, gyrA, gyrB and Int1 genes. Conclusions: Our study revealed a high prevalence of S. aureus in chacuterie products in Bobo-Dioulasso with antimicrobial profiles that show resistance to most antibiotics. These findings should inform and augment efforts to raise awareness among local supermarket owners on adequate food manufacturing practices as well as promoting food safety and hygiene. [ABSTRACT FROM AUTHOR]

Abstract Background Staphylococcus aureus can colonize and infect a variety of animal species. In dairy herds, it is one of the leading causes of mastitis cases. The objective of this study was to characterize the S. aureus isolates recovered from nasal swabs of 249 healthy cows and 21 breeders of 21 dairy farms located in two provinces of Algeria (Tizi Ouzou and Bouira). Methods The detection of enterotoxin genes was investigated by multiplex PCRs. Resistance of recovered isolates to 8 antimicrobial agents was determined by disc-diffusion method. The slime production and biofilm formation of S. aureus isolates were assessed using congo-red agar (CRA) and microtiter-plate assay. Molecular characterization of selected isolates was carried out by spa-typing and Multi-Locus-Sequence-Typing (MLST). Results S. aureus was detected in 30/249 (12%) and 6/13 (28.6%) of nasal swabs in cows and breeders, respectively, and a total of 72 isolates were recovered from positive samples (59 isolates from cows and 13 from breeders). Twenty-six of these isolates (36.1%) harbored genes encoding for staphylococcal enterotoxins, including 17/59 (28.8%) isolates from cows and 9/13 (69.2%) from breeders. Moreover, 49.1% and 92.3% of isolates from cows and breeders, respectively, showed penicillin resistance. All isolates were considered as methicillin-susceptible (MSSA). Forty-five (76.3%) of the isolates from cows were slime producers and 52 (88.1%) of them had the ability to form biofilm in microtiter plates. Evidence of a possible zoonotic transmission was observed in two farms, since S. aureus isolates recovered in these farms from cows and breeders belonged to the same clonal lineage (CC15-ST15-t084 or CC30-ST34-t2228). Conclusions Although healthy cows in this study did not harbor methicillin-resistant S. aureus isolates, the nares of healthy cows could be a reservoir of enterotoxigenic and biofilm producing isolates which could have implications in human and animal health.

Background: Staphylococcus aureus can colonize and infect a variety of animal species. In dairy herds, it is one of the leading causes of mastitis cases. The objective of this study was to characterize the S. aureus isolates recovered from nasal swabs of 249 healthy cows and 21 breeders of 21 dairy farms located in two provinces of Algeria (Tizi Ouzou and Bouira). Methods: The detection of enterotoxin genes was investigated by multiplex PCRs. Resistance of recovered isolates to 8 antimicrobial agents was determined by disc-diffusion method. The slime production and biofilm formation of S. aureus isolates were assessed using congo-red agar (CRA) and microtiter-plate assay. Molecular characterization of selected isolates was carried out by spa-typing and Multi-Locus-Sequence-Typing (MLST). Results: S. aureus was detected in 30/249 (12%) and 6/13 (28.6%) of nasal swabs in cows and breeders, respectively, and a total of 72 isolates were recovered from positive samples (59 isolates from cows and 13 from breeders). Twenty-six of these isolates (36.1%) harbored genes encoding for staphylococcal enterotoxins, including 17/59 (28.8%) isolates from cows and 9/13 (69.2%) from breeders. Moreover, 49.1% and 92.3% of isolates from cows and breeders, respectively, showed penicillin resistance. All isolates were considered as methicillin-susceptible (MSSA). Forty-five (76.3%) of the isolates from cows were slime producers and 52 (88.1%) of them had the ability to form biofilm in microtiter plates. Evidence of a possible zoonotic transmission was observed in two farms, since S. aureus isolates recovered in these farms from cows and breeders belonged to the same clonal lineage (CC15-ST15-t084 or CC30-ST34-t2228). Conclusions: Although healthy cows in this study did not harbor methicillin-resistant S. aureus isolates, the nares of healthy cows could be a reservoir of enterotoxigenic and biofilm producing isolates which could have implications in human and animal health. [ABSTRACT FROM AUTHOR]

Abstract Background Staphylococcus aureus (S. aureus), especially methicillin-resistant S. aureus (MRSA), is a known disease-causing bacteria with many associated health hazards. Staphylococcal food poisoning can result from staphylococcal enterotoxins (SEs). Methods In this study, 50 S. aureus isolates were isolated from the gastrointestinal tract (GIT) clinical samples of patients with food poisoning in clinical laboratories at Mansoura University Hospital, Egypt. For determination their antibiogram, these isolates were tested for antimicrobial sensitivity against 12 antimicrobial agents using the agar disk diffusion test. After DNA extraction from the isolates, conventional polymerase chain reaction (PCR) was used to detect mecA and SEs genes. Results As a result, all isolates were ampicillin and cefoxitin-resistant, while 86% (43 of 50) of the tested isolates exhibited multidrug resistance (MDR). In contrast, the highest sensitivity was confirmed against vancomycin, linezolid and quinolones, namely ciprofloxacin and norfloxacin. Although 100% of the isolates were mecA positive, staphylococcal enterotoxin genes set-A, set-B, set-C, set-G, set-M, and set-O genes were detected in 56%, 20%, 8%, 32%, 16%, and 24%, of the tested isolates, respectively. Finally, isolates encompassing SEs genes were used to validate a microarray chip, indicating its potential for a better methodological approach for detecting and identifying SEs in human samples. Conclusion The genotypic findings of this study may help explain the enterotoxigenic patterns in S. aureus among Egyptian patients with food poisoning.

Rajiha A Ibrahim,1– 3 Nega Berhe,1 Zelalem Mekuria,3,4 Eyasu T Seyoum,3 Joan-Miquel Balada-Llasat,3,5 Tamrat Abebe,6 Solomon H Mariam,1 Estifanos Tsige,2 Surafel Fentaw Dinku,2 Shu-Hua Wang3,7 1Aklilu Lemma Institute of Pathobiology, Addis Ababa University, Addis Ababa, Ethiopia; 2Bacterial, Parasitic and Zoonotic Research Directorate, Ethiopian Public Health Institute, Addis Ababa, Ethiopia; 3Global One Health Initiative (GOHi), The Ohio State University, Columbus, OH, USA; 4Veterinary Preventive Medicine, Colleges of Veterinary Medicine, The Ohio State University, Columbus, OH, USA; 5Department of Pathology, College of Medicine, The Ohio State University, Columbus, OH, USA; 6Department of Microbiology, Immunology, and Parasitology, Schools of Medicine, College of Health Sciences, Addis Ababa University, Addis Ababa, Ethiopia; 7Division of Infectious Diseases, Department of Internal Medicine, College of Medicine, The Ohio State University, Columbus, OH, USACorrespondence: Rajiha A Ibrahim, Bacterial, Parasitic and Zoonotic Research Directorate, Ethiopian Public Health Institute, PO Box: 1242, Addis Ababa, Ethiopia, Tel +251920602640, Email rajihabubeker@gmail.com; Ibrahim.258@osu.eduBackground: Staphylococcus aureus causes a wide range of infections from mild skin and soft tissue to severe life-threatening bacteremia. The pathogenicity of S. aureus infections is related to various bacterial surface components and extracellular proteins such as toxic-shock syndrome (TSS) toxin and Panton-Valentine leukocidin (PVL). In this study we determine the antimicrobial resistance of isolated strains and their virulence genes in Ethiopia.Methods: A total of 190 archived S. aureus isolates from four Ethiopia Antimicrobial Resistance (AMR) Surveillance sites were analyzed. The identification of S. aureus was done by matrix-assisted laser desorption/ionization-time of flight (MALDI-TOF Biotyper) and antimicrobial susceptibility test (AST) was done using VITEK® 2. Multiplex PCR was used to detect mecA, mecC, pvl and spa genes and super-antigens (sea, seb, sec, seh and sej staphylococcal enterotoxins).Results: A total of 172 isolates were confirmed as S. aureus, 9 (5.23%) were methicillin-resistant S. aureus (MRSA) and 163 (94.76%) were methicillin-susceptible S. aureus (MSSA). AST showed that 152 (88.4%) isolates were resistant to penicillin; 90 (52.32%) resistant to trimethoprim-sulfamethoxazole; and 45 (26.16%) resistant to tetracycline. A total of 66 (38.37%) isolates harbored at least one staphylococcal enterotoxin gene and 31 (46.96%) isolates had more than one. The most frequent enterotoxin gene encountered was seb 28 (16.28%). The TSST-1 gene was detected in 23 (13.37%). Presence of staphylococcal enterotoxin gene showed significant association with antibiotic resistance to cefoxitin, benzylpenicillin, oxacillin, erythromycin, clindamycin, tetracycline and SXT. The pvl gene was detected in 102 (59.3%) of isolates. Isolates from patients below 15 years of age showed significantly high numbers of pvl gene (P = 0.02). Presence of sej (P = 0.011) and TSST-1 (P < 0.001) genes were associated with the presence of pvl gene.Conclusion: In this study, isolates were highly resistant to oral antibiotics and the pvl, seb, sea and TSST-1 genes were prevalent.Keywords: MRSA, enterotoxin genes, Panton-Valentine leucocidin, PVL, Ethiopia

Background: Staphylococcus aureus (S. aureus), especially methicillin-resistant S. aureus (MRSA), is a known disease-causing bacteria with many associated health hazards. Staphylococcal food poisoning can result from staphylococcal enterotoxins (SEs). Methods: In this study, 50 S. aureus isolates were isolated from the gastrointestinal tract (GIT) clinical samples of patients with food poisoning in clinical laboratories at Mansoura University Hospital, Egypt. For determination their antibiogram, these isolates were tested for antimicrobial sensitivity against 12 antimicrobial agents using the agar disk diffusion test. After DNA extraction from the isolates, conventional polymerase chain reaction (PCR) was used to detect mecA and SEs genes. Results: As a result, all isolates were ampicillin and cefoxitin-resistant, while 86% (43 of 50) of the tested isolates exhibited multidrug resistance (MDR). In contrast, the highest sensitivity was confirmed against vancomycin, linezolid and quinolones, namely ciprofloxacin and norfloxacin. Although 100% of the isolates were mecA positive, staphylococcal enterotoxin genes set-A, set-B, set-C, set-G, set-M, and set-O genes were detected in 56%, 20%, 8%, 32%, 16%, and 24%, of the tested isolates, respectively. Finally, isolates encompassing SEs genes were used to validate a microarray chip, indicating its potential for a better methodological approach for detecting and identifying SEs in human samples. Conclusion: The genotypic findings of this study may help explain the enterotoxigenic patterns in S. aureus among Egyptian patients with food poisoning. [ABSTRACT FROM AUTHOR]

Staphylococcus aureus contamination of food and food contact surfaces is a public health concern given its virulent and antimicrobial-resistant properties worldwide. In this study, a total of 181 MSSA isolates were analyzed for SE genes, antimicrobial resistance patterns, and spa types. Overall, 24.9% of isolates were positive for SE gene detection, with sea being the most prevalent classical SE (18.8%). The most predominant sample sources for SE gene contamination were hand swabs for sea (6/48), meat dishes for seb (3/14) and seafood dishes for sec (2/24). Antimicrobial resistance was also observed at relatively high frequencies for the clinically important antibiotics penicillin G and ampicillin (both 54.7%), followed by tetracycline (14.9%) and azithromycin (8.8%). In addition, characterization of spa types revealed spa type t5078 to be the most predominant (40.3%), with significant associations between spa types t127 and t5521 and the sea gene. This study offers insights into the enterotoxin gene and antimicrobial resistance profiles of S. aureus in cooked or ready-to-eat food to inform future surveillance and epidemiological studies. [ABSTRACT FROM AUTHOR]

Background and Objectives: Staphylococcus aureus is responsible for the majority of food poisoning all around the world. Nasal carriers of S. aureus and foodstuffs need for handling are important sources and vehicles to transmit this pathogen to ready-to-eat foods. According to hygienic standards, confectioners should not be contaminated with S. aureus. This study aimed to detect nasal carriers and creamy pastries contaminated with enterotoxigenic S. aureus in confectioneries of Shiraz, Iran. Materials and Methods: From the confectioneries of Shiraz city, 27 places in the north, south, center, west, and east areas were selected randomly then 100 creamy pastries samples and 117 nasal swabs were collected. Bacteriological and biochemical tests were performed to isolate S. aureus. The polymerase chain reaction (PCR) test was used to identify the virulence and enterotoxins genes of the S. aureus isolates. Agar disk diffusion was performed to find out the antibiotic resistance of the isolates. Results: Results revealed that 16.24 and 33 percent of workers and creamy pastries were contaminated with S. aureus respectively. Also, 100%, 37%, 58%, and 6% of nasal samples harbored femA, mecA, sea, and sec genes respectively. According to the results 97%, 70%, 54.5%, and 6% of creamy pastries isolates harbored femA, mecA, sea, and sec genes respectively. No isolate carried seb and sed genes. The results also showed that 41.5% of nasals and 5.5% of creamy pastry isolates harbored both sea and sec genes. The sea was the most common enterotoxin gene observed in nasal and creamy pastries. The results of the antimicrobial resistance test showed that 68.42% of nasal and 48.48% of creamy pastry isolates were resistant to cefocxitn (FOX) respectively. Both nasal (89%) and creamy pastry (82%) isolates presented the highest resistance to penicillin (P) and the most sensitivity to trimethoprim-sulphamethoxazole (SXT) (94%). Most of the isolates were sensitive to erythromycin (E), aztreonam (AZM), tetracycline (TE), trimethoprim (TMP), and ciprofloxacin (CP). Isolates of S. aureus harboring multi-enterotoxin genes were resistant to more antibiotics than others. Conclusion: The presence of enterotoxigenic S. aureus in the workers' nasal samples and creamy pastries of Shiraz confectioneries was high which is a potential public health hazard. [ABSTRACT FROM AUTHOR]

S. aureus is a pathogenic bacterium that causesinfections. Its virulence is due to surface components, proteins, virulence genes, SCCmec, pvl, agr, and SEs, which are low molecular weight superantigens. SEs are usually encoded by mobile genetic elements, and horizontal gene transfer accounts for their widespread presence in S. aureus. This study analyzed the prevalence of MRSA and MSSA strains of S. aureus in two hospitals in Greece between 2020–2022 and their susceptibility to antibiotics. Specimens collected were tested using the VITEK 2 system and the PCR technique to detect SCCmec types, agr types, pvl genes, and sem and seg genes. Antibiotics from various classes were also tested. This study examined the prevalence and resistance of S. aureus strains in hospitals. It found a high prevalence of MRSA and that the MRSA strains were more resistant to antibiotics. The study also identified the genotypes of the S. aureus isolates and the associated antibiotic resistances. This highlights the need for continued surveillance and effective strategies to combat the spread of MRSA in hospitals. This study examined the prevalence of the pvl gene and its co-occurrence with other genes in S. aureus strains, as well as their antibiotic susceptibility. The results showed that 19.15% of the isolates were pvl-positive and 80.85% were pvl-negative. The pvl gene co-existed with other genes, such as the agr and enterotoxin genes. The results could inform treatment strategies for S. aureus infections. [ABSTRACT FROM AUTHOR]

Abstract Background Staphylococcus aureus is an important opportunistic pathogen of raw milk and milk products, and the enterotoxins cause food poisoning. Milk and milk products are important reservoirs of enterotoxin-producing S. aureus. The aims of this systematic review were to estimate the pooled prevalence of S. aureus, including methicillin-resistant Staphylococcus aureus (MRSA), and to summarize their molecular characteristics, assess the potential sources of S. aureus contamination in bulk milk and analyse the antimicrobial resistance patterns of the isolates. Methods Following Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, we searched publicly available scientific online databases and search engines: PubMed, Research for Life, African Journal Online (AJOL), and Google Scholar. In addition, the reference lists of the identified studies were manually checked for relevant literature. A random effects model using the DerSimonian method was used to compute pooled prevalence estimates, and the data were transformed using variance stabilizing Freeman-Tukey double arcsine transformation. Results A total of 38 studies were included in this systematic review. The pooled prevalence of S. aureus was highest in raw cow milk (30.7%), followed by camel milk (19.3%), goat milk (13.6%) and pasteurized milk (3.8%). The pooled prevalence of S. aureus in locally produced soft cheese (ayib) and traditional fermented milk (ergo) was 18.6% and 14.9%, respectively. The pooled prevalence of MRSA in milk and milk products was 0.73%. In this study, 58.9% of S. aureus isolates recovered from milk and milk products harbored at least one type of enterotoxin gene. Raw milk of the three species (cow, goat and camel) showed the highest S. aureus pooled prevalence rate at processing plants (50.3%), followed by milk collection centers (MCCs) (47.1%), selling points (34.5%), farm bulk milk (25.8%), milking buckets (24.8%) and udder milk (20.3%). Water for washing milking utensils (39.3%) was more contaminated than swab samples from farm workers’ nares (31.5%), milkers’ hands (25.9%), MCCs containers (23.8%), bulk tanks (20.4%), udders (15.6%), milking buckets (14.2%) and towels (10%). S. aureus isolates were highly resistant to penicillin G (92%), followed by ampicillin (82%) and amoxicillin (62.6%). The pooled multidrug resistance (MDR) was high (62.1%). Conclusion This systematic review revealed a high and increasing level of S. aureus contamination of raw milk from udder to MCCs or processing plants. Enterotoxin genes and MRSA were reported in milk, milk products and samples from farm workers. S. aureus showed resistance to different antimicrobial agents, with β-lactams showing the highest pooled antimicrobial resistance and the level of MDR was high. The results of this study indicated that the consumption of raw milk and milk products may predispose consumers to staphylococcal food poisoning. Application of good hygiene and handling practices across the dairy value chain starting from farm, udder health, milk cooling, heat treatment of milk before drinking and rational use of antibiotics in veterinary medicine can reduce the potential health risks from S. aureus and MRSA contamination of milk and milk products.

Background and Objectives: Staphylococcus aureus is responsible for the majority of food poisoning all around the world. Nasal carriers of S. aureus and foodstuffs need for handling are important sources and vehicles to transmit this pathogen to ready-to-eat foods. According to hygienic standards, confectioners should not be contaminated with S. aureus. This study aimed to detect nasal carriers and creamy pastries contaminated with enterotoxigenic S. aureus in confectioneries of Shiraz, Iran. Materials and Methods: From the confectioneries of Shiraz city, 27 places in the north, south, center, west, and east areas were selected randomly then 100 creamy pastries samples and 117 nasal swabs were collected. Bacteriological and biochemical tests were performed to isolate S. aureus. The polymerase chain reaction (PCR) test was used to identify the virulence and enterotoxins genes of the S. aureus isolates. Agar disk diffusion was performed to find out the antibiotic resistance of the isolates. Results: Results revealed that 16.24 and 33 percent of workers and creamy pastries were contaminated with S. aureus respectively. Also, 100%, 37%, 58%, and 6% of nasal samples harbored femA, mecA, sea, and sec genes respectively. According to the results 97%, 70%, 54.5%, and 6% of creamy pastries isolates harbored femA, mecA, sea, and sec genes respectively. No isolate carried seb and sed genes. The results also showed that 41.5% of nasals and 5.5% of creamy pastry isolates harbored both sea and sec genes. The sea was the most common enterotoxin gene observed in nasal and creamy pastries. The results of the antimicrobial resistance test showed that 68.42% of nasal and 48.48% of creamy pastry isolates were resistant to cefocxitn (FOX) respectively. Both nasal (89%) and creamy pastry (82%) isolates presented the highest resistance to penicillin (P) and the most sensitivity to trimethoprim-sulphamethoxazole (SXT) (94%). Most of the isolates were sensitive to erythromycin (E), aztreonam (AZM), tetracycline (TE), trimethoprim (TMP), and ciprofloxacin (CP). Isolates of S. aureus harboring multi-enterotoxin genes were resistant to more antibiotics than others. Conclusion: The presence of enterotoxigenic S. aureus in the workers’ nasal samples and creamy pastries of Shiraz confectioneries was high which is a potential public health hazard.

Objective: Staphylococcus aureus (S. aureus) has evolved as one of the most significant bacteria causing food poisoning outbreaks worldwide. This study was carried out to investigate the prevalence, antibiotic sensitivity, virulence, and enterotoxin production of S. aureus in raw milk of cow from small-scale production units and house-raised animals in Damietta governorate, Egypt. Material and Methods: The samples were examined bacteriologically, and antimicrobial sensitivity testing was carried out. Moreover, isolates were characterized by the molecular detection of antimicrobial resistance, virulence, and enterotoxin genes. Results: Out of 300 milk samples examined, S. aureus was isolated from 50 samples (16.7%). Antibiotic sensitivity testing revealed that isolates were resistant to β-lactams (32%), tetracycline (16%), and norfloxacin (16%); however, they showed considerable sensitivity to ceftaroline and amikacin (72%). Multidrug-resistance (MDR) has been observed in eight isolates (16%), with a MDR index (0.5) in all of them. Of the total S. aureus isolates obtained, methicillin-resistant S. aureus (MRSA) has been confirmed molecularly in 16/50 (32%) and was found to carry mecA and coa genes, while virulence genes; hlg (11/16, 68.75%) and tsst (6/16, 37.5%) were amplified at a lower percentage, and they showed a significant moderate negative correlation (r = −0.59, p-value > 0.05). Antibiotic resistance genes have been detected in resistant isolates relevant to their phenotypic resistance: blaZ (100%), tetK (50%), and norA (50%). Fifty percent of MRSA isolates carried the seb enterotoxin gene. Conclusion: High detection rate of MRSA and MDR isolates from milk necessitates the prompt implementation of efficient antimicrobial stewardship guidelines, especially at neglected small-scale production units. [J Adv Vet Anim Res 2022; 9(1.000): 113-121]

Staphylococcus aureus contamination of food and food contact surfaces is a public health concern given its virulent and antimicrobial-resistant properties worldwide. In this study, a total of 181 MSSA isolates were analyzed for SE genes, antimicrobial resistance patterns, and spa types. Overall, 24.9% of isolates were positive for SE gene detection, with sea being the most prevalent classical SE (18.8%). The most predominant sample sources for SE gene contamination were hand swabs for sea (6/48), meat dishes for seb (3/14) and seafood dishes for sec (2/24). Antimicrobial resistance was also observed at relatively high frequencies for the clinically important antibiotics penicillin G and ampicillin (both 54.7%), followed by tetracycline (14.9%) and azithromycin (8.8%). In addition, characterization of spa types revealed spa type t5078 to be the most predominant (40.3%), with significant associations between spa types t127 and t5521 and the sea gene. This study offers insights into the enterotoxin gene and antimicrobial resistance profiles of S. aureus in cooked or ready-to-eat food to inform future surveillance and epidemiological studies.

Background: Staphylococcus aureus is an important opportunistic pathogen of raw milk and milk products, and the enterotoxins cause food poisoning. Milk and milk products are important reservoirs of enterotoxin-producing S. aureus. The aims of this systematic review were to estimate the pooled prevalence of S. aureus, including methicillin-resistant Staphylococcus aureus (MRSA), and to summarize their molecular characteristics, assess the potential sources of S. aureus contamination in bulk milk and analyse the antimicrobial resistance patterns of the isolates. Methods: Following Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, we searched publicly available scientific online databases and search engines: PubMed, Research for Life, African Journal Online (AJOL), and Google Scholar. In addition, the reference lists of the identified studies were manually checked for relevant literature. A random effects model using the DerSimonian method was used to compute pooled prevalence estimates, and the data were transformed using variance stabilizing Freeman-Tukey double arcsine transformation. Results: A total of 38 studies were included in this systematic review. The pooled prevalence of S. aureus was highest in raw cow milk (30.7%), followed by camel milk (19.3%), goat milk (13.6%) and pasteurized milk (3.8%). The pooled prevalence of S. aureus in locally produced soft cheese (ayib) and traditional fermented milk (ergo) was 18.6% and 14.9%, respectively. The pooled prevalence of MRSA in milk and milk products was 0.73%. In this study, 58.9% of S. aureus isolates recovered from milk and milk products harbored at least one type of enterotoxin gene. Raw milk of the three species (cow, goat and camel) showed the highest S. aureus pooled prevalence rate at processing plants (50.3%), followed by milk collection centers (MCCs) (47.1%), selling points (34.5%), farm bulk milk (25.8%), milking buckets (24.8%) and udder milk (20.3%). Water for washing milking utensils (39.3%) was more contaminated than swab samples from farm workers' nares (31.5%), milkers' hands (25.9%), MCCs containers (23.8%), bulk tanks (20.4%), udders (15.6%), milking buckets (14.2%) and towels (10%). S. aureus isolates were highly resistant to penicillin G (92%), followed by ampicillin (82%) and amoxicillin (62.6%). The pooled multidrug resistance (MDR) was high (62.1%). Conclusion: This systematic review revealed a high and increasing level of S. aureus contamination of raw milk from udder to MCCs or processing plants. Enterotoxin genes and MRSA were reported in milk, milk products and samples from farm workers. S. aureus showed resistance to different antimicrobial agents, with β-lactams showing the highest pooled antimicrobial resistance and the level of MDR was high. The results of this study indicated that the consumption of raw milk and milk products may predispose consumers to staphylococcal food poisoning. Application of good hygiene and handling practices across the dairy value chain starting from farm, udder health, milk cooling, heat treatment of milk before drinking and rational use of antibiotics in veterinary medicine can reduce the potential health risks from S. aureus and MRSA contamination of milk and milk products. [ABSTRACT FROM AUTHOR]

ABSTRACT: Objectives: This study aimed to detect and characterise methicillin-resistant Staphylococcus aureus (MRSA) from retail meat in the Czech Republic.Methods: Isolates were identified by PCR detection of the S. aureus-specific fragment Sa442 and mecA gene. spa typing, MLST, detection of genes encoding staphylococcal enterotoxins, Panton–Valentine leukocidin (pvl), exfoliative toxins A and B (eta and etb), toxic shock syndrome toxin (tst) and staphylokinase (sak), detection of φSa3 prophage and antimicrobial susceptibility testing were performed.Results: Of 65 raw meat samples examined (poultry, beef, pork and rabbit), 23 (35.4%) were positive for MRSA. Twelve positive samples originated from poultry (12/33; 36.4%), while the remaining eleven came from pork (9/9; 100%) and pork/beef mixed minced meat (2/5; 40.0%). Eight spa types belonging to five different sequence types (STs) were identified. ST398 was the most frequent (28/36; 77.8%), presenting spa types t011, t034, t2576, t4132, t588 and t899. Other livestock-associated MRSA STs (ST9-t899, ST5-t002, ST692-t8646 or the newly described ST4034-t899) were also sporadically identified. In seven isolates (19.4%), one or more staphylococcal enterotoxin genes were detected, with sea, seg and sei prevailing. Three isolates from turkey [ST398-t899 (n = 2) and ST398-t011] harboured the sak gene, and the latter also harboured the sea gene. Seven isolates from poultry harboured the φSa3 prophage and were resistant to tetracycline.Conclusion: Specific kinds of meat appear to be a possible source of MRSA, although the risk to humans is hard to define. Therefore, surveillance of MRSA in meat as well as hygienic practices should be improved.

ObjectiveTo investigate the prevalence, antimicrobial susceptibility, and enterotoxin gene of Staphylococcus aureus (S. aureus) isolates in ready-to-eat (RTE) foods in Guangzhou from 2008 to 2019.MethodsRTE food samples were randomly collected from retail outlets and supermarkets in 11 districts of Guangzhou and the isolation and identification of S. aureus were performed. All isolated S. aureus were tested for antimicrobial susceptibility, enterotoxin genes and multilocus sequence typing (MLST). Methicillin resistant S. aureus (MRSA) isolates were further characterized by staphylococcal cassette chromosome mec (SCCmec) typing.ResultsA total of 157 S. aureus isolates(11.22%) were detected from 1 399 RTE food samples in Guangzhou from 2009 to 2018. The prevalence of S. aureus in cooked pork samples was significantly higher than those in non-meat samples (17.95% vs 9.43%, P

Methicillin-resistant Staphylococcus aureus (MRSA) is a growing public health concern; however, there is limited information about MRSA and VRSA (Vancomycin-resistant S. aureus) among animal-origin food. Therefore, this study intended to elucidate the prevalence, enterotoxin existence, antimicrobial resistance profiles, and antimicrobial resistance genes of S. aureus strains isolated from chicken carcasses, ready-to-eat (RTE) chicken meat sandwiches, and buffalo milk samples marketed in Mansoura City, Egypt. Of the 240 samples examined, 52.1 % were contaminated with S. aureus , with a mean count of 4.11 log 10 CFU/g. A total of 250 isolates were verified as S. aureus by PCR targeting nuc gene, of which 39.2 % (98/250) harbored at least one S. aureus enterotoxin (SE) gene. The predominant SE genes were sea (61.2 %, 60/98), followed by sed (58.2 %, 57/98), sec (38.8 %, 38/98), and seb (27.6 %, 27/98). All isolates were resistant to at least one antimicrobial, with an average MAR (multiple antibiotic resistance) index of 0.530. Four isolates exhibited resistance to all antimicrobial agents tested. Interestingly, 100 %, 76.4 %, 35.6 %, 30.8, 10.4 %, 6 %, and 1.6 % of isolates were resistant to penicillin, azithromycin, oxacillin, ceftaroline, vancomycin, linezolid, and daptomycin, respectively. Of the 250 S. aureus strains tested, 38 % were confirmed as MRSA by mecA gene, while 10.4 % were identified as VRSA by vanA gene. The high prevalence of MRSA and VRSA isolates among samples tested is worrisome. Hence, monitoring antimicrobial usage in veterinary medicine and applying strict hygienic measures during food handling and processing is imperative to prevent the spread of such resistant bacteria and protect public health. [Display omitted] • 52.1 % of examined poultry and dairy samples were contaminated with S. aureus. • 88.8 % of S. aureus isolates were multidrug-resistant and 39.2 % were enterotoxigenic. • 38 % of S. aureus strains were confirmed as MRSA by the mecA gene. • The sea was the most common staphylococcal enterotoxins genes. • 10.4 % of the isolates were vancomycin-resistant and harbored vanA gene. [ABSTRACT FROM AUTHOR]

Objective: Staphylococcus aureus (S. aureus) has evolved as one of the most significant bacteria causing worldwide food poisoning outbreaks. This study was carried out to investigate the prevalence, antibiotic sensitivity, virulence, and enterotoxin production of S. aureus in raw milk of cow from small-scale production units and house-raised animals in Damietta governorate, Egypt. Material and Methods: The samples were examined bacteriologically, and antimicrobial sensitivity testing was carried out. Moreover, isolates were characterized by the molecular detection of antimicrobial resistance, virulence, and enterotoxin genes. Results: Out of 300 milk samples examined, S. aureus was isolated from 50 samples (16.7%). Antibiotic sensitivity testing revealed that isolates were resistant to β-lactams (32%), tetracycline (16%), and norfloxacin (16%); however, they showed considerable sensitivity to ceftaroline and amikacin (72%). Multidrug-resistance (MDR) has been observed in eight isolates (16%), with a MDR index (0.5) in all of them. Of the total S. aureus isolates obtained, methicillin-resistant S. aureus (MRSA) has been confirmed molecularly in 16/50 (32%) and was found to carry mecA and coa genes, while virulence genes; hlg (11/16, 68.75%) and tsst (6/16, 37.5%) were amplified at a lower percentage, and they showed a significant moderate negative correlation (r = -0.59, p-value > 0.05). Antibiotic resistance genes have been detected in resistant isolates relevant to their phenotypic resistance: blaZ (100%), tetK (50%), and norA (50%). Fifty percent of MRSA isolates carried the seb enterotoxin gene. Conclusion: High detection rate of MRSA and MDR isolates from milk necessitates the prompt implementation of efficient antimicrobial stewardship guidelines, especially at neglected smallscale production units. [ABSTRACT FROM AUTHOR]

This study was conducted to investigate the prevalence, antimicrobial susceptibility, and molecular characterization of Aeromonas spp. from wild Nile tilapia from Lake Manzala and the lake water. Swabs from the surface, gills, and internal organs of apparently healthy Nile tilapia (n =100) and lake water (n = 25) were collected and examined bacteriologically for the presence of Aeromonas spp. The isolates obtained were tested for their susceptibility to 11 antimicrobial agents using the disk diffusion method. The presence of antibiotic resistance genes (blaTEM, sul1, tetA(A), and aadA1) and virulence genes (enterotoxins) (alt, ast, and act) was determined using conventional polymerase chain reaction. Overall, Aeromonas spp. were recovered from 69% of Nile tilapia (Oreochromis niloticus) samples and 80% of water samples. Four types of aeromonads were detected in all the samples examined, namely, A. hydrophila, A. sobria, A. caviae, and A. schubertii, with A. hydrophila predominating in both the fish and the lake water samples. The antimicrobial resistance profiles of the isolates showed very high resistance to ampicillin, penicillin, sulfamethoxazole/trimethoprim, and oxytetracycline and considerable resistance to streptomycin. However, all isolates were sensitive to cefotaxime. Molecular characterization revealed the presence of the act (100%) and alt (37.5%) genes, but ast was not found in any of the isolates. Specific amplification bands of the antimicrobial resistance genes blaTEM, sul1, and tetA(A) were detected in all the tested isolates, whereas aadA1 (12.5%) was found only in one isolate of A. hydrophila from Nile tilapia. The presence of these enterotoxigenic and resistant Aeromonas spp. in the fish and water samples from Lake Manzala could pose a potential public health threat to human consumers and fish handlers in the study area; moreover, these species carry a risk for the transfer of resistance genes to other microbial communities in the lake [ABSTRACT FROM AUTHOR]

Bacillus cereus, usually ingested by food, can cause two types of disease due to the presence of toxins: vomiting and diarrhea syndrome. Systemic infections can also occur. The aim was to detect genes for enterotoxins (hblA, entFM) and emetic toxin (cer) and to investigate the genetic heterogeneity of B. cereus isolates from food, environment and human stool. Identification of B. cereus was performed by means of selective medium, classical biochemical test and polymerase chain reaction (PCR). Toxin genes were detected by PCR. Typing was performed by random amplified polymorphic DNA (RAPD). EntFM gene was present in all stool and food samples and in 28/30 environmental isolates. HblA gene was present in 29/30 stool, 23/30 food and 24/30 environmental isolates. Cer gene was present in 30/30 stool, 28/30 food and 25/30 environmental isolates. The RAPD results show high heterogeneity among the isolates from each group. In the cumulative dendrogram, representative isolates from all three groups formed two clusters with a difference of 53%. The detection of toxin genes in all B. cereus isolates indicated these bacteria as potentially pathogenic and a serious threat for human health. The presence of isolates from all three groups in the same cluster suggests the existence of similar strains in the environment, food and patients, which is in line with the circulation of strains in nature through the food chain.

S. aureus is a pathogenic bacterium that causesinfections. Its virulence is due to surface components, proteins, virulence genes, SCCmec, pvl, agr, and SEs, which are low molecular weight superantigens. SEs are usually encoded by mobile genetic elements, and horizontal gene transfer accounts for their widespread presence in S. aureus. This study analyzed the prevalence of MRSA and MSSA strains of S. aureus in two hospitals in Greece between 2020–2022 and their susceptibility to antibiotics. Specimens collected were tested using the VITEK 2 system and the PCR technique to detect SCCmec types, agr types, pvl genes, and sem and seg genes. Antibiotics from various classes were also tested. This study examined the prevalence and resistance of S. aureus strains in hospitals. It found a high prevalence of MRSA and that the MRSA strains were more resistant to antibiotics. The study also identified the genotypes of the S. aureus isolates and the associated antibiotic resistances. This highlights the need for continued surveillance and effective strategies to combat the spread of MRSA in hospitals. This study examined the prevalence of the pvl gene and its co-occurrence with other genes in S. aureus strains, as well as their antibiotic susceptibility. The results showed that 19.15% of the isolates were pvl-positive and 80.85% were pvl-negative. The pvl gene co-existed with other genes, such as the agr and enterotoxin genes. The results could inform treatment strategies for S. aureus infections.

Staphylococcus aureus (S. aureus) is a pathogen in community-acquired or hospital infections. Hence, the identification of this pathogen in clinical samples is a health concern and demands continued surveillance and close monitoring. In the current study, S. aureus strains were isolated from various clinical specimens in the Shariati Hospital, Tehran, Iran. Samples were studied to discover S. aureus enterotoxin-coding genes A (sea), B (seb), C (sec), and D (sed). It was found that 21% enterotoxigenic S. aureus harbored sea gene, 39% were carried seb gene, 37% were positive for sec-gene, and 3% were carried sed gene. None of all S. aureus strains harbored more than one of the enterotoxigenic genes. Based on the data obtained from the current study, it could be suggested that seb and sec genes are good candidates for the identification of S. aureus in clinical specimens. Further investigations are required to discover the association between these genes and the pathogenicity of this bacteria, and finally using these data in clinical settings.

Raw milk is usually contaminated with enterotoxin-producing Staphylococcus ¬aureus, which is regularly associated with staphylococcal food poisoning. The present study was conducted to investigate the occurrence of Staphylococcus aureus and enterotoxin producing strains in cow raw milk in Erbil province and to assess genotypic (multiplex PCR) versus phenotypic by reversed passive latex agglutination (RPLA) assays for staphylococcal enterotoxin detection. A total of 150 samples of caw raw milk (75 from direct milk and 75 bulk tank milk) were collected randomly from milk collectors and different farms in Erbil city. The Staphylococcus aureus isolates were identified conventionally and confirmed by PCR. Then, staphylococcal enterotoxins(SEs) from A to D were examined by RPLA, and types of related genes (sea-sed) were detected by multiplex PCR. S. aureus was recovered from 14 (18.6%) samples from direct milk and 32 samples (42.6%) from bulk tank milk. Of the total strains studied, 65.2% were determined to have some staphylococcal enterotoxin genes; however, only 34.7% produced a detectable amount of the staphylococcal enterotoxins. The most frequently produced enterotoxin gene was type A (60%), followed by sec (30%), sea+sec (10%) and genes seb and sed did not occur. A relatively high discrepancy was observed between the results of RPLA and multiplex PCR, especially with SEA. Our findings showed that cow raw milk in Erbil city is contaminated with toxigenic strains of S.aureus.

ABSTRACT The aim of this study was to describe the microbiological characteristics and profile of genes encoding enterotoxins in 95 Staphylococcus aureus isolates obtained between April 2011 and December 2014 from foodstuffs, persons and surfaces of retail food stores. After microbiological identification and antimicrobial susceptibility testing, polymerase chain reactions (PCR) were performed, targeting sea, seb, sec, sed and see genes that code for classical enterotoxins (ET) A-E, and three additional genes: seg , seh and sei , coding for so-called “new enterotoxins” G, H and I. The isolates were characterized by Pulsed Field Gel Electrophoresis (PFGE), and five selected isolates were further analyzed through Multi Locus Sequence Typing (MLST). It is noteworthy that 54.7% of the examined isolates harbored one or more of the investigated ET gene types. Most positive isolates carried more than one ET gene up to five types; seg was the most frequent ET gene, followed by sei. Five enterotoxin-coding isolates also coded for some antimicrobial resistance genes. Two of them, and four additional non-enterotoxic isolates carried erm genes expressing inducible clindamycin resistance. PFGE-types were numerous and diverse, even among enterotoxin-coding strains, because most isolates did not belong to known foodborne outbreaks and the sampling period was long. MLST profiles were also varied, and a new ST 3840 was described within this species. ST 88 and ST 72 enterotoxin-coding isolates have been identified in other regions in association with foodborne outbreaks. This manuscript reports the first systematic investigation of enterotoxin genes in S. aureus isolates obtained from foodstuffs and infected people in Uruguay.

Aims: The aim of this study was to characterize Staphylococcusaureus isolates of food origin (dairy and meat products, pastries and sandwiches) determining the carriage in enterotoxin genes and the antimicrobial resistance pheno/genotypes. Methods and results: A total of 300 food samples were collected and analysed for the detection of S. aureus. The presence of enterotoxin genes was investigated by multiplex PCRs. Resistance of isolates to 11 antimicrobials was determined using disc diffusion method and molecular characterization of methicillin‐resistant S. aureus was carried out by spa typing and multilocus sequence typing. Overall, 51 out of 300 samples (17%) were contaminated with S. aureus, and 104 isolates were recovered. In all, 65 of these isolates (62·5%) harboured one or more genes encoding for staphylococcal enterotoxins, being seg and sei the most observed genes. The highest resistance profile was ascribed to penicillin G (95·19%). Five isolates were methicillin‐resistant (MRSA) harbouring the mecA gene. All MRSA isolates belonged to the sequence type ST5 and to two different spa types (t450 and t688); the MRSA‐t450 isolate carried the scn gene (specific marker of the immune evasion cluster system), but the four MRSA‐t688 isolates were scn negative. The MRSA isolates carried enterotoxin genes but were negative for the genes of the Panton Valentine leukocidine (lukF/S‐PV). Conclusion: The presence of enterotoxigenic S. aureus isolates, including MRSA, in food samples can represent a risk for public health. Significance and Impact of this Study: This work describes the molecular characteristics of MRSA strains isolated from foods in Algeria and it can contribute to an extended database concerning the S. aureus isolated from food origin. [ABSTRACT FROM AUTHOR]

Food poisoning caused by Staphylococcus aureus (S. aureus) toxins is considered one of the foremost public health threat that usually occurs through the ingestion of raw milk contaminated with staphylococcal enterotoxins. The current study spotlights on the prevalence, antibiogram and genetic diversity of S. aureus enterotoxin genes. One hundred and fifty of raw milk (90) and ice cream (60) samples were randomly collected from local markets from Sadat city, Egypt. S. aureus was recovered from 44% of raw milk and 20% of ice cream samples. The identification for the obtained S. aureus isolates was confirmed through targeting the nuc gene. Antibiogram pattern of 32 S. aureus isolates showed high resistance to Cefoxitin, Sulpha/Trimethoprim, Tetracycline, Norfloxacin, Penicillin and Cephradine. However, high susceptibility to Gentamycin and Vancomycin were observed. Multiplex PCR was a competent practise for the recognition of Staphylococcus enterotoxin (SE) genes (SEA , SEB and SED). The phylogenetic analysis of the SED gene of enterotoxigenic S. aureus strains showed identical similarity with 100% to each other and high similarity with other international isolates in GenBank from different localities and sources. The frequency of enterotoxigenic S. aureus strains in milk products could have serious hazardous effects on humans. These results suggested possible strains transmission between different geographical areas through the food and milk product trades. [ABSTRACT FROM AUTHOR]

Bacillus cereus is a gram positive, spore forming bacteria. It produces hemolytic and non-hemolytic enterotoxins, which lead to diarrhea, food poisoning and self-limiting gastrointestinal track (GIT) infections. The organism occurs worldwide, mostly the outbreaks due to B. cereus are linked to fried rice and milk products. The present study focused on detection of hemolytic (hblA, hblC) and non-hemolytic (nheA) toxin encoding gene subunits of B. cereus isolated form different milk samples. A total of 100 milk samples (refrigerated pasteurized, raw, heat treated and packed milk) were tested for the presence of B. cereus. Isolates were confirmed by biochemical testing. DNA was isolated through phenol chloroform method and confirmed by gel electrophoresis. For the detection of hemolytic and non-hemolytic subunits multiplex polymerase chain reaction (PCR) was performed. Out of 100 samples, 20% were found positive to B. cereus by biochemical testing. Among the 20% positive milk samples 50, 40 and 10% were heat treated refrigerated milk, raw milk and packaged milk, respectively. Results of multiplex PCR showed 100, 30 and 9% positive nheA, hblC and hblA genes subunits, respectively in positive isolates of B. cereus. Prevalence of B. cereus in milk could be a potential threat for milk consumers. Appropriate pasteurization and storage conditions must be followed to evade theB. cereus contamination. [ABSTRACT FROM AUTHOR]

The aim of this study was to describe the microbiological characteristics and profile of genes encoding enterotoxins in 95 Staphylococcus aureus isolates obtained between April 2011 and December 2014 from foodstuffs, persons and surfaces of retail food stores. After microbiological identification and antimicrobial susceptibility testing, polymerase chain reactions (PCR) were performed, targeting sea, seb, sec, sed and see genes that code for classical enterotoxins (ET) A-E, and three additional genes: seg, seh and sei, coding for so-called "new enterotoxins" G, H and I. The isolates were characterized by Pulsed Field Gel Electrophoresis (PFGE), and five selected isolates were further analyzed through Multi Locus Sequence Typing (MLST). It is noteworthy that 54.7% of the examined isolates harbored one or more of the investigated ET gene types. Most positive isolates carried more than one ET gene up to five types; seg was the most frequent ET gene, followed by sei. Five enterotoxin-coding isolates also coded for some antimicrobial resistance genes. Two of them, and four additional non-enterotoxic isolates carried erm genes expressing inducible clindamycin resistance. PFGE-types were numerous and diverse, even among enterotoxin-coding strains, because most isolates did not belong to known foodborne outbreaks and the sampling period was long. MLST profiles were also varied, and a new ST 3840 was described within this species. ST 88 and ST 72 enterotoxin-coding isolates have been identified in other regions in association with foodborne outbreaks. This manuscript reports the first systematic investigation of enterotoxin genes in S. aureus isolates obtained from foodstuffs and infected people in Uruguay. [ABSTRACT FROM AUTHOR]

Abstract We characterised 227 Staphylococcus aureus isolates from retail food and food handlers’ gloves samples obtained through food surveillance and risk assessment studies between 2011 and 2014. Of 227 isolates, five (2.2%) were methicillin-resistant and belonged to sequence types ST80 (n = 3) and ST6 (n = 2). All five isolates belonged to SCCmec type IV, were Panton-Valentine leukocidin (pvl)-negative and staphylococcal enterotoxin genes-positive. Resistance to azithromycin was found in ST80 isolates, in addition to resistance to beta-lactams. Our finding of two clinically relevant methicillin-resistant S. aureus (MRSA) strains (ST80 and ST6) in ready-to-eat food and food contact surfaces at retail in Singapore suggests food and food contact surfaces as potential environmental sources of MRSA in the community.

Aim: This review gives an outline of the assessment of enterotoxigenic Staphylococcus aureus tainting levels in raw milk from different sources in Egypt and characterization of enterotoxigenic strains utilizing a technique in light of PCR to identify genes coding for the production of staphylococcal enterotoxin (SE). The obtained data were compared with results from the application of the reversed passive latex. Materials and Methods: Multiplex PCR and reversed passive latex agglutination (RPLA) were used. A total of 141 samples of raw milk (cow's milk=33, buffalo's milk=58, and bulk tank milk=50) were investigated for S. aureus contamination and tested for enterotoxin genes presence and toxin production. Results: S. aureus was detected in 23 (16.3%) samples phenotypically and genotypically by amplification of nuc gene. The S. aureus isolates were investigated for SEs genes (sea to see) by multiplex PCR and the toxin production by these isolates was screened by RPLA. SEs genes were detected in six isolates (26.1%) molecularly; see was the most observed gene where detected in all isolates, two isolates harbored seb, and two isolates harbored sec. According to RPLA, three isolates produced SEB and SEC. Conclusion: The study revealed the widespread of S. aureus strains caring genes coding for toxins. The real significance of the presence of these strains or its toxins in raw milk and their possible impact a potential hazard for staphylococcal food poisoning by raw milk consumption. Therefore, detection of enterotoxigenic S. aureus strains in raw milk is necessary for consumer safety.

Development of a novel biopreservative harmless to human health has gained increasing attention to control spoilage and pathogenic bacteria in food products. The aims of the present work were to characterise partially purified substance from Bacillus velezensis BUU004 (PBV), evaluate its cytotoxicity, and assess the presence of encoding genes associated with enterotoxin production in B. velezensis BUU004. The highest antibacterial activity was achieved at 18 h post-incubation in stationary growth phase. The PBV containing bacteriocin displayed proteinaceous nature because its activity was partially inactivated by chymotrypsin and papain, and fully degraded by pepsin, proteinase K and trypsin. Bacteriocin in PBV was thermoresistant up to 96°C, and pH stable ranging from 3.0 - 9.0. It also showed a broad spectrum of antibacterial activity against B. cereus, B. coagulans, Listeria monocytogenes, Micrococcus luteus, Staphylococcus aureus, Escherichia coli, E. coli O157:H7, and Salmonella Typhimurium. The molecular weight of the bacteriocin was approximately 5.75 kDa, and the amino acid sequence revealed 43% similarity with existing antimicrobial peptides as determined by an LC-MS/MS analysis. Furthermore, B. velezensis BUU004 produced the bacteriocin that has a low IC50 of 927.4 µg/mL to HK-2 cells along with absence of enterotoxin genes: cytotoxin K (cytK), hemolysin (hlyII), hemolytic enterotoxin HBL (hblABCD), nonhemolytic enterotoxin NHE (nheABC) and cereulide (cesABCD), indicating its basic biosafety characteristic. Our results suggest that a bacteriocin produced by B. velezensis BUU004 has promising potential as a safe biopreservative in the food industry. [ABSTRACT FROM AUTHOR]

Aims: This investigation was undertaken to study the prevalence, enterotoxin gene profile and molecular epidemiology of Aeromonads from various sources of water (182) and fish (173). Methods and Results: A total of 116 Aeromonas sp. were isolated, of which 48 (26·37%) were from water and 68 (34·62%) were from fish samples collected from retail markets and fish farms. The Aeromonads were recovered from all types of water sources viz. drinking water (13%), surface waters (26%) and fish ponds (69%). The most prevalent species recovered from drinking water was A. hydrophila, from fish ponds it was A. caviae, from surface water sources A. hydrophila and A. caviae were recovered more frequently, and A. hydrophila and A. veronii bv. sobria were isolated predominantly from gills of fish samples. On multiplex PCR analysis for the detection of enterotoxin genes (act, alt, ast), the above mentioned Aeromonas species frequently contained enterotoxin genes, irrespective of their sources. From isolates across all the sources, act (63%) and alt (57%) genes were encountered more frequently than ast (6%). The enterobacterial repetitive intergenic consensus sequences polymerase chain reaction was used for typing of isolates and most of the isolates from water and fish were related, owing to similar ecosystem. Conclusion: A wide distribution of enterotoxin genes in Aeromonads from water and fish is a potential public health threat and molecular genotyping can be helpful to study epidemiology of the pathogen. Significance and Impact of the Study: A high proportion of isolates recovered from diverse water sources, particularly potable drinking water and fish samples carried one or more enterotoxin genes thereby indicating a potential pathogenic nature of isolates from these sources. The genetic relatedness was detected amongst many isolates recovered from water sources and fish samples indicating circulation of familiar virulent clones in the aquatic environments. [ABSTRACT FROM AUTHOR]

Bacillus cereus, a bacteria frequently associated with food spoilage, is responsible for 2 different foodborne illness in humans: a diarrheal disease, associated with cytotoxin K, hemolysin BL and a non-hemolytic enterotoxin, and an emetic syndrome, associated with the cereulide toxin. The aim of this study is to investigate the occurrence of B. cereus in 515 hard and soft cheeses collected in southern Italy. The strains were molecularly characterized for the presence of hblA, hblC, hblD, nheA, nheB, nheC, cytK, and entFM genes, related to the production of enterotoxins (trimeric hemolysin BL, trimeric non-hemolytic enterotoxin, cytotoxin K and enterotoxin FM). One hundred thirty eight samples (26.8%) were found contaminated by B. cereus. One hundred of the contaminated samples (72.5%) showed a level of B. cereus contamination ≤103 CFU/g, whereas 9 (6.5%) samples showed a contamination >105 CFU/g. Seven different molecular profiles were found among the 138 strains of B. cereus isolated. The most common profile was nheABC-entFM, found in 42 strains, followed by the hblACD-nheABC-cytK-entFM, found in 33 strains, the nheABC-cytK-entFM, found in 24 strains, the hblACDnheABC-entFM, found in 11 strains, the hblACD-nheAC-entFM, found in 15 strains, and the nheC-entFM, found in 12 strains. Eleven strains did not harbored any of these genes. In 7.2% (37/515) of samples, characterized by a bacterial contamination >103 CFU/g, we found B. cereus strains harboring genes encoding for at least one complete enterotoxin. [ABSTRACT FROM AUTHOR]

Aims: Methicillin‐sensitive and methicillin‐resistant Staphylococcus aureus (MSSA and MRSA, respectively) in the nostrils of dogs and workers at an animal shelter were cultured. Staphylococcal toxin genes were analysed to identify potential health concerns. Methods and Results: Samples were obtained from 441 dogs and 9 workers. The respective isolation rates of S. aureus and MRSA were 49·0% (216/441) and 1·6% (7/441) for shelter dogs and 44·4% (4/9) and 33·3% (3/9) for workers, respectively. Isolation of S. aureus in summer (61·9%) and in adult dogs (59·2%) were significantly higher than those in winter (35·8%) and in juvenile dogs (33·3%) (P < 0·001), respectively. The predominant enterotoxin genotypes and combination profiles of S. aureus were (sea, seb, seg, sei, sem, sen, seo, seu) and (sea, sea‐seb, and seg‐sei‐sem‐sen‐seo‐seu), respectively, and 20% of isolates carried food poisoning‐associated enterotoxins. The se profiles in shelter dogs were different from those in general pet dogs and their owners. MRSA isolates were identified as SCCmec IV and VII, and they shared se combination profiles of (sec‐seg‐sei‐sel‐sem‐sen‐seo‐seu) and (seb‐sek‐seq). MRSA in this shelter had similar microbiological characteristics as those reported in CA‐MRSA ST59 in humans. Conclusions: Human health‐associated bacteria and food poisoning‐related toxin genes were identified. Further evaluations of health concerns in animal shelters are necessary. Significance and Impact of the Study: This is the first study to focus on se prevalence and MRSA characteristics in an animal shelter in Taiwan. The MRSA characteristics determined in this study were similar to those of CA‐MRSA strains isolated from communities in the past, indicating potential health risks in cities. [ABSTRACT FROM AUTHOR]

This study investigated the prevalence of Staphylococcus aureus enterotoxin genes and shiga toxin -producing Escherichia coli (STEC) in fish and evaluated quality parameters of examined fish. A total of 150 fish samples belonging to 6 species (25/each species) were cultured on Baird–Parker agar and eosin methylene blue agar. Staphylococcal enterotoxin genes and virulence genes (stx1, stx2, and eaeA genes) in E. coli serotypes were determined by multiplex PCR. Aerobic plate count (APC), Enterobacteriaceae count, coliform count, and Pseudomonas count were performed. Also, levels of total volatile base nitrogen and histamine in fish were determined. The prevalence of S. aureus ranged from 4% to 36% and count from 2 to 4 log10CFU/g. The sed, sea, and seb genes in S. aureus isolates were detected with percentages of 40%, 26.6%, and 20%, respectively. The E. coli serotype O26 carried stx1, stx2, and eaeA. The APCs, Enterobacteriaceae counts, and Pseudomonas counts ranged from 5.1 to 7.2, from 2.01 to 3.9, and from 2.1 to 3.1 log10 CFU/g, respectively. The most probable number (MPN) of coliform ranged from 1.3 to 3.6 log10/g. Levels of total volatile basic nitrogen and histamine ranged from 29.2 to 12.2 and from 0.6 to 4.6 mg/100 g, respectively. Also, the value of thiobarbituric acid was highly significant (1.1 ± 0.084 mg MDA/kg) in Trachurus mediterraneus samples compared with those levels obtained from other fish species. Our findings concluded that those fish species could constitute a public health hazard as fish are reservoirs for enterotoxigenic S. aureus and Shiga toxin producing E. coli strains. This study highlighted the importance of screening of fish for enterotoxigenic S. aureus strains and STEC isolates, and also assessing the quality parameters of fish. [ABSTRACT FROM AUTHOR]

This study defined the prevalence of enterotoxin gene-positive Staphylococcus aureus strains among food handlers and non-food processing healthy nasal S. aureus carriers in central Iran. Meticillin-resistant S. aureus (MRSA) strains were diagnosed by cefoxitin disk diffusion. PCR was used to detect the mecA, Sa442, and enterotoxin genes. Out of the 1113 food handlers, 224 (20.1%) were nasal carriers of S. aureus and 157 (70.1%) of these isolates were positive for one or more enterotoxin genes. The most prevalent enterotoxin gene was sei (40.2%), followed by seg (35.3%), sea (23.5%), seb (15.2%), sec (5.5%), and seh (2.7%). See and sed genes were not found. Sixty seven (42.7%) of enterotoxin gene-positive isolates possessed a single enterotoxin gene, and 64 (40.8%), 23 (14.7%), and 3 (1.9%) contained two, three, or four enterotoxin genes, respectively. The most frequently detected gene combination was sei/seg (n = 35, 22.3%). Thirty seven (16.5%) isolates were diagnosed as MRSA, and 27 (73%) of these strains were positive for at least one enterotoxin gene. Out of 546 healthy controls, 100 individuals were identified as S. aureus nasal carriers; among the strains, 39 (39%) were positive for at least one enterotoxin gene. Only one (1%) CA-MRSA was identified among the strains from the volunteers. A high prevalence of meticillin resistant and enterotoxin-positive S. aureus were documented in food handlers. We suggest that this may be due to the frequent handling of contaminated foodstuffs and that this is possibly related to the elevated frequencies of acquired staphylococcal food poisoning in this population. [ABSTRACT FROM AUTHOR]

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A total of 100 random samples of some edible beef offal represented by liver, heart, lung and spleen (25 of each) were subjected to bacteriological examination for Mesophilic bacterial count, Enterobacteriaceae count, Coliforms count, Staphylococcal count, the incidence of S. aureus and detection of enterotoxin genes of S. aureus to evaluate their quality. The mean value of Mesophilic bacterial count / g of liver, heart, lung and spleen were 3.9×104 ± 7.7×103, 3.6×104 ± 5.5×103, 3.03×104 ± 5.0×103 and 5.4×104 ± 7.3×103 cfu/g, respectively. The mean value of Enterobacteriaceae count / g of liver, heart, lung and spleen were 2.3×104 ± 6.2×103, 1.4×104 ± 4.3×103, 1.2×104 ± 2.9×103 and 1.5×104 ± 2.3×103 cfu/g, respectively. The mean value of Coliforms count / g of liver, heart, lung and spleen were 6.4×102 ± 1.0×102, 5.6×102 ± 1.0×102, 6.1×102 ± 1.0×102 and 8.2×102 ± 9.4×10 MPN/g, respectively. The mean value of Staphylococci count / g of liver, heart, lung and spleen were 1.1×102 ± 1.4×10, 1.1×102 ± 1.7×10, 1.3×102 ± 1.3×10 and 1.7×102 ± 1.7×10 cfu/g, respectively. The incidence of S. aureus isolated from examined liver, heart, lung and spleen samples were 36%, 44%, 64% and 32%, respectively. Analysis of the PCR products obtained from amplification reaction of extracted DNA from 10 identified S. aureus strains in this study for detection of enterotoxins genes by agarose gel electrophoresis revealed that the specific band for SEA gene (120bp) was detected in 3(30%) one from liver, heart and spleen out of 10 isolates, while the specific band for SEB gene (478bp) was not detected in any isolate. The specific band for SEC gene (257bp) was detected in 1(10%) from lung out of 10 isolates, also the specific band for SED gene (317bp) was detected in 1(10%) from lung out of 10 isolates. The specific band for SEA, SEC genes (120bp, 257bp) was detected in 1(10%) from spleen out of 10 isolates. [ABSTRACT FROM AUTHOR]

The major contamination sources, biofilm-forming ability and biocide resistance of Staphylococcus aureus in tilapia-processing plants were evaluated. Twenty-five processing control points were analysed twice in two factories, including whole tilapias, frozen fillets, water and food-contact surfaces. No final product was contaminated with S. aureus. However, high concentrations of S. aureus carrying enterotoxin (se) genes were found in several processing points of both factories due to the application of inadequate hygienic and handling procedures, which generate a high risk of cross-contamination of the tilapia fillets with staphylococcal enterotoxins. Nine S. aureus strains were characterized by RAPD-PCR using primers AP-7, ERIC-2 and S. A wide diversity of se gene profiles was detected, most strains being multi-se-carriers. All S. aureus strains showed high biofilm-forming ability on stainless steel and polystyrene. Biofilm-forming ability was correlated with the presence of fliC H7 and the type of origin surface (metallic or plastic). A marked resistance of S. aureus to peracetic acid and sodium hypochlorite was also observed, required doses being higher than those recommended by manufacturers to be eradicated. Case-by-case approaches are thus recommended to determine the sources and degree of contamination present in each factory, which would allow applying precise responses that avoid, or at least reduce, the presence of bacterial pathogens and the emergence of antimicrobial resistance. [ABSTRACT FROM AUTHOR]

Aim: This study gives an outline of the assessment of enterotoxigenic Staphylococcus aureus tainting levels in raw milk from different sources in Egypt and characterization of enterotoxigenic strains utilizing a technique in light of PCR to identify genes coding for the production of staphylococcal enterotoxin (SE). The obtained data were compared with results from the application of the reversed passive latex. Materials and Methods: Multiplex PCR and reversed passive latex agglutination (RPLA) were used. A total of 141 samples of raw milk (cow's milk=33, buffalo's milk=58 and bulk tank milk=50) were investigated for S. aureus contamination and tested for enterotoxin genes presence and toxin production. Results: S. aureus was detected in 23 (16.3%) samples phenotypically and genotypically by amplification of nuc gene. The S. aureus isolates were investigated for SEs genes (sea to see) by multiplex PCR and the toxin production by these isolates was screened by RPLA. SEs genes were detected in six isolates (26.1%) molecularly; see was the most observed gene where detected in all isolates, two isolates harbored seb and two isolates harbored sec. According to RPLA, three isolates produced SEB and SEC. Conclusion: This study revealed the widespread of S. aureus strains caring genes coding for toxins. The real significance of the presence of these strains or its toxins in raw milk and their possible impact a potential hazard for staphylococcal food poisoning by raw milk consumption. Therefore, detection of enterotoxigenic S. aureus strains in raw milk is necessary for consumer safety. [ABSTRACT FROM AUTHOR]

The aim of this study was to investigate the Staphylococcal enterotoxin (SE) and directly detect the five classical SEA, SEB, SEC, SED and SEE gene in Staphylococcus aureus strains from different food samples by real-time PCR. We studied totally 3650 different food samples such as milk and dairy products, meat and meat products, poultry and eggs, canned food, coffee, cocoa and derived products, honey, confectionery and bakery, ready-to-eat foods, beverages in food control laboratory. We found that a total of 36 (0.98%) S. aureus strains were isolated and only 14 (0.38%) out of 36 S. aureus strains were found to be enterotoxingenic. Milk samples were found to be most contaminant among the products. The most prevalent SE types were SEA 7 (19.4%). Commercial EIA kit results were used to compare with the real-time PCR results. SE results were found to be same with these two methods. This study showed that prevalence and type of the staphylococcal enterotoxin may vary from food to food. It is important to know this data to prevent outbreaks. Additionally, automated DNA isolation and real-time PCR methods can be performed to direct enterotoxin gene detection rapidly and reliably. This technique can be also used for food safety and clinical diagnosis applications. [ABSTRACT FROM AUTHOR]

Staphylococcal food poisoning outbreaks (SFPOs) are frequently reported in France. However, most of them remain unconfirmed, highlighting a need for a better characterization of isolated strains. Here we analyzed the genetic diversity of 112 Staphylococcus aureus strains isolated from 76 distinct SFPOs that occurred in France over the last 30 years. We used a recently developed multiple-locus variable-number tandem-repeat analysis (MLVA) protocol and compared this method with pulsed field gel electrophoresis (PFGE), spa-typing and carriage of genes (se genes) coding for 11 staphylococcal enterotoxins (i.e. SEA, SEB, SEC, SED, SEE, SEG, SEH, SEI, SEJ, SEP, SER). The strains known to have an epidemiological association with one another had identical MLVA types, PFGE profiles, spa-types or se gene carriage. MLVA, PFGE and spa-typing divided 103 epidemiologically unrelated strains into 84, 80 and 50 types respectively demonstrating the high genetic diversity of S. aureus strains involved in SFPOs. Each MLVA type shared by more than one strain corresponded to a single spa-type except for one MLVA type represented by 4 strains that showed two different-but closely related-spa-types. The 87 enterotoxigenic strains were distributed across 68 distinct MLVA types that correlated all with se gene carriage except for four MLVA types. The most frequent se gene detected was sea, followed by seg and sei and the most frequently associated se genes were sea-seh and sea-sed-sej-ser. The discriminatory ability of MLVA was similar to that of PFGE and higher than that of spa-typing. This MLVA protocol was found to be compatible with high throughput analysis, and was also faster and less labour-intensive than PFGE. MLVA holds promise as a suitable method for investigating SFPOs and tracking the source of contamination in food processing facilities in real time.

A total of 100 minced meat samples were collected from different butchers in Port-Said city for isolation and identification of Staph. aureus, Escherichia coli and Salmonella spp.. The results revealed that Staph. aureus, E. coli and Salmonella spp. could be detected in a percentage of 14%, 12% and 1% respectively from minced meat samples. Molecular characterizations of all isolated S. aureus, E. coli and Salmonella spp. were confirmed using 16S rRNA, phoA and invA, respectively by conventional PCR at 791 bp; 720 bp and 284 bp, respectively. Multiplex PCR was developed with specific primers for the detection of different enterotoxin genes (Sea, Seb, Sec, Sed and See) of Staph. aureus, (Stx1, Stx2, STa and lt) of E. coli and (stn) of Salmonella which may be considered a significant in food safety threat. The obtained results showed that the positive serotypes for enterotoxin genes were (Seb in 3 isolates and Sed in one isolate) of Staph. aureus at 164 bp and 278 bp respectively; (Stx2 in 2 isolates and STa in 2 isolates) of E. coli at 779 bp and 229 bp, respectively. Conventional PCR is rapid methods for the confirmation of Staph. aureus, E. coli and Salmonella spp., while multiplex PCR is a useful technique for detection of enterotoxin genes. The public health hazards of this isolated organism, as well as recommended measures to improve quality status of minced meat were discussed. [ABSTRACT FROM AUTHOR]

Aims The main goal was to estimate the prevalence of methicillin-resistant Staphylococcus aureus on hands and in nose of health care professionals. Methods and Results Detection of Staph. aureus on hands or in the nose of 169 individuals was performed. Nasal and hand carriage was found in 39·6 and in 8·9% respectively. About 17·2% of the individuals were carriers of methicillin-resistant Staph. aureus (MRSA) in the nose and 4·7% on hands. The majority of nasal MRSA were resistant to β-lactams, erythromycin and ciprofloxacin. All nasal MRSA were SCC mec type IV and Panton-Valentine leukocidin (PVL) negative. One MRSA isolated from hand was SCC mec type V. About 75·6% of MRSA isolates presented the same or closely related restriction patterns. Sixty per cent of Staph. aureus from hands and from noses from the same individual were the same strain. Conclusions MRSA nasal carriage was high considering healthy health care professionals but in accordance with high level of MRSA infection in Portugal. Isolates recovered in this study seemed to be different from major clones previously isolated in other Portuguese hospitals. Significance and Impact of the Study These findings may have implications on the knowledge of healthy health care workers as vehicles of MRSA infections among the community. Presence of several virulence factors may contribute to increased pathogenesis in case of infection. [ABSTRACT FROM AUTHOR]

Bacillus cereus is a major foodborne pathogen that can cause a type of diarrhea. Diarrheal syndrome results from the ingestion of food products contaminated with enterotoxin-producing B. cereus . This study investigated the presence of four enterotoxins genes in 130 B. cereus isolated from various food products from Jiangxi, China. The expression levels of the enterotoxin genes in three B. cereus strains of different origins were subsequently analyzed. All of the B. cereus strains harbor at least 1 enterotoxin gene, whereas 34 strains harbor 2 enterotoxin genes, 44 strains harbor 3 enterotoxin genes, and 47 strains carry all of the four enterotoxin genes. The detection rates of the cytK , hblD , nheA , and entFM enterotoxin genes in all B. cereus isolates were 71%, 43%, 92%, and 99%, respectively. Moreover, the food matrix significantly affected the expression of these enterotoxin genes. The majority of the enterotoxin genes were also downregulated in four food matrices, indicating that the relative expression of certain enterotoxin genes, especially the entFM gene, was lower in a real food matrix than in laboratory broths. Hence, these data revealed that B. cereus is a serious health hazard and that the food matrix may influence the virulence expression of B. cereus . Our results provide better insights into the physiology of the microorganism grown in food products. [ABSTRACT FROM AUTHOR]