Foodborne viruses — an emerging pathogens

Viral foodborne illnesses which have become a significant cause of all reported foodborne illnesses in recent years and considered as an emerging risk in veterinary public health. Foodborne transmission can occur by contamination of food by infected food handlers, by contamination of food during the production process and by consumption of products of animal origin harboring a zoonotic virus. Microbiological genomics studies discovered that noroviruses and hepatitis A viruses were primarily associated with food-handler transmission and sewage-contaminated foods while hepatitis E was associated with consumption of raw or undercooked meat of pig or wild animals. Routine harmonized surveillance of viral outbreaks, and surveillance of virus occurrence in food commodities, in combination with systematic strain typing, and joint expertise from veterinary, food, and clinical microbiologists would be recommended to aid source attribution studies and identify risk prevention measures

Determination of staphylococcal enterotoxins in cheese by immunoenzyme assays

Staphylococcal food poisoning is one of the most common foodborne diseases resulting from the ingestion of staphylococcal enterotoxins (SEs) preformed in foods by enterotoxigenic strains of coagulase-positive staphylococci (CPS), mainly Staphylococcus aureus. The presence of enterotoxigenic strains of coagulase-positive staphylococci in raw milk during the production process leads to the contamination of products and outbreaks of alimentary intoxication. The problem of Staphylococcus aureus in cheese remains significant on a global level. Domestic cheese contaminated with enterotoxigenic staphylococci can result in the formation of enterotoxin, which can produce foodborne illness when the product is ingested. Due to microbiological contamination, microbiological criteria are tools that can be used in assessing the safety and quality of foods. In order to avoid foodborne illness, the Serbian Regulation on General and Special Conditions for Food Hygiene (Official Gazette of RS, No. 72/10) provides microbiological criteria for staphylococcal enterotoxins in dairy products

Factors influencingmicrobial transmission in a meat processing plant

The review paper examines the main risk factors for microbial contamination of meat at different stages of its processing. Particular emphasis has been placed on primary animal processing being the most hazardous in terms of microbial contamination of meat. Carcass cross-contamination most frequently occurs during skinning and evisceration since hides and the digestive tract are the primary sources of microbial pathogens. It is necessary to observe stringent sanitary and hygienic rules when performing these operations. Continuous cold chain management along all following stages of meat processing and control of the sanitary status of cold chambers during meat storage are of extreme importance. An increase in the microbial counts due to the high number of manual operations was observed during meat cutting, boning, and trimming. Subsequent stages of meat processing, including mincing, curing, the addition of spices, also promote significant microbial growth. Strict control regarding detection of dangerous pathogens, especially L. monocytogenes, is needed at this stage. In general, to minimize problems linked with meat and meat product safety, it is necessary to take timely measures on sanitary treatment of meat processing facilities, including the prevention of biofilm formation

The nitrite content in domestic and foreign cooked sausages from the Serbian market

The nitrite content (expressed as NaNO2) was measured in 236 samples of different types of domestic and foreign cooked sausages from the Serbian market, according to standard ISO procedure. The highest content of nitrite (expressed as NaNO2) was found in fine comminuted cooked sausages from foreign producers. Similarly, the coarse comminuted cooked sausages from foreign producers contained higher nitrite compared to domestically produced cooked sausages. According to National and EU Regulations, the maximum allowed nitrate content (expressed as NaNO2) is 150 mg/kg. All tested cooked sausages had nitrite levels below the regulatory limits set by National Regulation and Regulation (EC) No. 601/2014, but the highest nitrite contents were found in cooked sausages from foreign producers

Efficiency evaluation of a bivalent vaccine in the prophylaxis of mastitis in cows

Mastitis in cows represents one of the most actual problems in intensive dairy production. The longtime different approaches to the treatment of mastitis have not offered a suitable solution, and the problem of mastitis is still present and acute. Prevention of pathogen penetration into the mammary gland, its colonization and multiplication impose a constant need for regular inspections of milk, as well as preventive and therapeutic measures to reduce the incidence of mastitis. Studies in the field of vaccination of ruminants against mastitis pathogens suggest a limited success in obtaining significant results in immunoprophylaxis. Considering the results of other researchers and our own research, and bearing in mind the problems mastitis caused by Staphylococcus aureus and Streptococcus agalactiae represent, the aim of this study was the preparation and testing of an indigenous vaccine prepared with two stable strains, SAU 7 (S. aureus) and SAG 3 (Str.agalactiae). The dose was 5 mL/cow and consisted of inactivated bacterial S. aureus SAU 7 cells in a concentration of 1x1010 cfu/mL and Str. agalactiae SAG 3 in a concentration of 4 x 109 cfu/mL. The number of somatic cells in the milk samples during the whole study period was higher in vaccinated cows in both groups compared with the control, but this difference was not statistically significant. The concentration of immunoglobulin IgG in the milk of vaccinated cows was significantly higher than the concentration of this class of proteins in the milk of unvaccinated cows. [Projekat Ministarstva nauke Republike Srbije, br. III 46002

Surface adsorption and survival of SARS-CoV-2 on frozen meat

The first case of a severe acute respiratory syndrome caused by coronavirus-2 was reported in December 2019 in China. The disease spread globally quickly, causing the 2019–2021 COVID-19 pandemic. The meat industry became concerned over the possibility of transmitting the virus in the slaughterhouse environment. The level of air exchange strongly affects the distribution of SARS-CoV-2 aerosols within the slaughterhouses. The adsorption of the SARS-CoV-2 virus on the surface of the frozen meat is dictated mainly by the interplay of electrostatic forces between the virion and tissue (pH) and environmental conditions (temperature and humidity) in the vicinity of adsorption micro-location. Suppose the virus contaminates the meat surface, whereby pH is 5.5 or less. In that case, it firmly adsorbs due to bonds established by protonated amine group and a hydrogen bond between the COOH group of the viral protein and oxygen in hydroxyl groups present on meat surfaces. The meat surface, coated with a thin water film, interacts with the SARS-CoV-2 virions by establishing strong hydrogen bonds. Although there is no proof of COVID-19 contraction by food consumption, the strong surface adsorption and ability of SARS-CoV-2 to survive meat freezing indicate a potential risk of virus transmission by meat

Occurrence of Escherichia coli in mussels (Mytilus galloprovincialis) from farms in Boka Kotorska Bay, Southern Adriatic Sea

This study reports the occurrence of Escherichia coli in 243 mussel samples collected along the Boka Kotorska Bay (six harvesting areas), which is located in the Southern Adriatic Sea. Bivalve molluscs can concentrate contaminants from their water environment, so because of that, determination of E. coli levels is an important parameter for microbial pollution assessment in the investigated areas. The number of E. coli ranged between 4600 MPN E. coli/100 g. Statistical analysis of the number of E. coli in mussels established that the mussel farm vl. Duško Vlahović (M5) had the highest mean E. coli levels (949.00 ± 2541 MPN E. coli/100 g), while the lowest mean level was recorded in Boka mussels (M1) (149.20 ± 258.80 MPN E. coli/100 g). Boka Kotorska bay is classified as a Class B mussel production area because it has 32.9% of samples with E. coli MPN values between the 20-230 MPN/100g

Detection and quantification of hepatitis e virus genome in pig liver samples originating from Serbian retail establishments

Hepatitis E is considered an emerging human viral disease with a zoonotic nature, and domestic and wild pigs are the main reservoirs of hepatitis E virus (HEV) among animals. Pork liver is the target tissue of this virus. This study aimed to investigate the presence of HEV in commercial pig liver samples. Sixty samples were collected during one year from different retail outlets in Serbia. Furthermore, the collected samples were separated by four seasons, and every season included three months. The presence of HEV in the livers was examined by molecular analysis using RT-qPCR. The overall prevalence of the virus in analysed pig livers was 5%. HEV was detected in three livers, two in the first season and one in the second, while in the third and fourth season, no positive livers were detected. However, there were no statistically significant differences between the surveyed seasons. HEV was quantified in positive livers. Among positive livers, HEV concentrations ranged between 8×101 and 1.9×104 genome copies of the virus per gram. The presence of HEV in commercial pig livers indicates a potential risk for consumers. Appropriate heat treatment of meals during preparation is essential to eliminate the potential risk of developing the illness. © Published under licence by IOP Publishing Ltd

Stanje ekosistema za uzgoj pastrmke sa aspekta mikrobiološkog rizika

Control of microbiological status of ponds and a fish itself is of great importance while the aim of control is to detect indicators of faecal pollution and to evaluate the potential risk of consumption of contaminated aquacultural products. In this paper we investigated microbiological population of rainbow trout ponds, in trout itself and in sludge. Investigations were performed at the beginning of autumn, end of autumn and at the beginning of winter. Results indicated that microbiological status of the pond ecosystem was mainly satisfactory, although there were some sporadic cases of A.hydrophila on trout skin at the beginning of autumn