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Histamine content in selected production stages of fish products
2022
Madejska Anna | Pawul-Gruba Marzena | Osek Jacek
Histamine intoxication, known as scombroid fish poisoning, is caused by the consumption of foods with high levels of histamine. This biogenic amine is formed as a result of histidine decarboxylation by bacterial decarboxylases present in food, including fish and fish products. The aim of this study was to investigate the content of histamine at different production stages of canned, marinated and smoked fish.
Показать больше [+] Меньше [-]Histamine contents in raw long-ripening meat products commercially available in Poland
2021
Michalski, Mirosław | Pawul-Gruba, Marzena | Madejska, Anna
Many consumers seek long-ripening meat products. The availability of these highly distinctive cured pork varieties is continuously expanding and their safety should be subject to monitoring. One of potentially harmful substances in these products is histamine. The presence of this toxic amine is reported in many countries, even in high concentrations. However, the EU has not regulated the permissible histamine content in meat, in a situation at odds with that of regulated fish and fish products. This study established the usefulness of biogenic amine testing in long-ripening pork and furnished indicative concentrations potential useful as a background for future research in preparation for EU regulative intervention. A total of 97 samples of long-ripening meat products untreated by heat were bought from various shops in the Puławy and Lublin regions of Poland and tested for the presence of histamine using high-performance liquid chromatography with diode array. The histamine concentration ranged from below limit of detection to 346.64 mg/kg, where 3.47 mg/kg was the lowest in a positive sample. Histamine was detected in 48 samples (49.5%). The maximum amount of histamine was identified in dry ham and the minimum in traditional salami. The results of this study suggest that testing meat products for biogenic amines should be a very good indicator of the food safety of long-ripening meats. In half of the tested products, levels of biogenic amines potentially toxic to consumers were determined.
Показать больше [+] Меньше [-]Microbiological quality of farmed grass carp, bighead carp, Siberian sturgeon, and wels catfish from Eastern Poland
2018
Pyz-Łukasik Renata | Paszkiewicz Waldemar
The purpose of this study was to determine the microbiological quality of food fish and its safety for consumers.
Показать больше [+] Меньше [-]Multiplex real-time PCRs for detection of Salmonella, Listeria monocytogenes, and verotoxigenic Escherichia coli in carcasses of slaughtered animals
2016
Denis, Edyta | Bielińska, Katarzyna | Wieczorek, Kinga | Osek, Jacek
Introduction: The study objective was to develop and evaluate a new TaqMan multiplex real-time PCR method for Salmonella, L. monocytogenes, and verotoxigenic Escherichia coli (VTEC) detection in slaughtered animal carcasses.Material and Methods: The procedure included an enrichment step, DNA extraction, and two multiplex real-time PCRs. The first PCR detected the invA and hly genes of Salmonella and L. monocytogenes respectively, the second the vtx1, vtx2, and eae genes of VTEC.Results: The validation of this method resulted in 100% relative sensitivity, specificity, and accuracy as compared to the reference ISO methods. The limit of detection per swab sample was established at 1 cfu for Salmonella and L. monocytogenes and 2 cfu for VTEC. The authors analysed 265 slaughterhouse-collected swabs from cattle, pig, and poultry carcasses. Among 125 from cattle, 51 were positive for VTEC, 29 for Salmonella, and 1 for L. monocytogenes. Among swabs from pig carcasses (n = 95), three, two, and one sample were positive for these pathogens respectively. None of the microorganisms tested for was identified in 45 samples of poultry origin.Conclusion: The obtained results showed that the method developed can rapidly identify the main bacterial pathogens that may contaminate carcasses of food-producing animals.
Показать больше [+] Меньше [-]Why does Listeria monocytogenes survive in food and food-production environments?
2023
Osek Jacek | Wieczorek Kinga
Listeria monocytogenes is one of the most dangerous food-borne pathogens and is responsible for human listeriosis, a severe disease with a high mortality rate, especially among the elderly, pregnant women and newborns. Therefore, this bacterium has an important impact on food safety and public health. It is able to survive and even grow in a temperature range from -0.4°C to 45°C, a broad pH range from 4.6 to 9.5 and at a relatively low water activity (aW < 0.90), and tolerates salt content up to 20%. It is also resistant to ultraviolet light, biocides and heavy metals and forms biofilm structures on a variety of surfaces in food-production environments. These features make it difficult to remove and allow it to persist for a long time, increasing the risk of contamination of food-production facilities and ultimately of food. In the present review, the key mechanisms of the pathogen’s survival and stress adaptation have been presented. This information may grant better understanding of bacterial adaptation to food environmental conditions.
Показать больше [+] Меньше [-]First report of the presence of enterotoxin gene in coagulase-negative staphylococci recovered from meat of snails (Achatina achatina)
2022
Okafor, Arthur C. | Ogbo, Frank C. | Akharaiyi, Fred C. | Oladeinde, Henry B.
It has been suggested that coagulase-negative staphylococci can serve as reservoirs of virulence genes for other bacteria. This study assessed the presence of such genes in selected isolates recovered from meat of the giant African snail (Achatina achatina). Virulence genes were detected using a polymerase chain reaction targeting specific primers. Two representative isolates were identified using 16S rRNA gene sequencing. The results showed that the staphylococcal enterotoxin A gene (sea) was present in five out of the eight isolates studied. The isolates expressed resistance mainly to three antibiotics: chloramphenicol, norfloxacin and cloxacillin in descending order of incidence. Most importantly, the Staphylococcus sciuri isolate NEDU 181, in addition to being resistant to the three aforementioned antibiotics, also harboured the sea gene. Our findings demonstrate, for the first time, the presence of toxigenic and antibiotic-resistant coagulase-negative Staphylococcus spp. in commercially-available fresh snail meat. With staphylococcal enterotoxin A known to survive cooking temperature, this presents a food safety concern.
Показать больше [+] Меньше [-]Identification of histamine in fish and fish products in Poland during 2014–2018
2021
Pawul-Gruba, Marzena | Osek, Jacek
Histamine is one of the most important and toxic biogenic amines which may be present in food and may cause food poisoning in humans when contained at a high level. It is produced during bacterial decarboxylation of histidine in fish muscles. The aim of the study was to investigate the presence of histamine in fish and fish products available in Poland during 2014–2018. A total of 421 samples of raw (248), smoked (107), canned (50), and marinated fish (16) were analysed by high-performance liquid chromatography with diode array detection. Histamine was detected in 14.1% samples of raw fish, 29% of smoked fish, 22% of canned fish and 93.8% of marinated fish in concentrations ranging from 3.4 to 156.4 mg/kg. Content of this amine above 100 mg/kg was found in four samples: raw Atlantic salmon, smoked European sprat and two samples of marinated Atlantic herring. The study showed that fish and fish products on the Polish market generally meet the food safety criteria for histamine and are safe for consumers.
Показать больше [+] Меньше [-]Microbiological quality of farmed grass carp, bighead carp, Siberian sturgeon, and wels catfish from Eastern Poland
2018
Pyz-Łukasik, Renata | Paszkiewicz, Waldemar
The purpose of this study was to determine the microbiological quality of food fish and its safety for consumers. The study included 24 fish representing grass carp, bighead carp, Siberian sturgeon, and wels catfish. Specimens were collected in winter. Aerobic bacteria, psychrophilic, Enterobacteriaceae, Staphylococcus spp., and E. coli counts were made, and the presence of Salmonella spp., L. monocytogenes, S. aureus, and other coagulase-positive staphylococci was investigated. The microbiological analysis showed a similar level of aerobic, psychrophilic, and Staphylococcus spp. contamination of the four fish species. The Enterobacteriaceae count was higher in the muscles of grass carp and bighead carp than S. sturgeon and wels catfish. No pathogenic bacteria such as Salmonella spp., E. coli, L. monocytogenes, Staphylococcus aureus, or other coagulase positive staphylococci were found in samples of the examined fish species. The fresh fish examined in this study were of good microbiological quality and there was no health risk for consumers.
Показать больше [+] Меньше [-]Multiplex real-time PCRs for detection of Salmonella, Listeria monocytogenes, and verotoxigenic Escherichia coli in carcasses of slaughtered animals
2016
Denis Edyta | Bielińska Katarzyna | Wieczorek Kinga | Osek Jacek
Introduction: The study objective was to develop and evaluate a new TaqMan multiplex real-time PCR method for Salmonella, L. monocytogenes, and verotoxigenic Escherichia coli (VTEC) detection in slaughtered animal carcasses.
Показать больше [+] Меньше [-]Microbiological safety of food of animal origin from organic farms
2021
Sosnowski, Maciej | Osek, Jacek
The organic food sector and consumer interest in organic products are growing continuously. The safety and quality of such products must be at least equal to those of conventional equivalents, but attaining the same standards requires overcoming a particular problem identified in organic food production systems: the occurrence of bacterial pathogens such as Salmonella, Campylobacter, Listeria monocytogenes, Staphylococcus aureus and pathogenic Escherichia coli. These food-borne microorganisms were detected in the production environments of such food. The prevalence of pathogenic bacteria in organic livestock and products may be higher, but may also be the same as or lower than in like material from conventional farms. Furthermore, the incidence of antimicrobial-resistant bacteria was more often detected in conventional than in organic production. The aim of this review was to present the recent information on the microbiological safety of food of animal origin produced from raw materials from organic farms.
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