Raw Dairy Products Research Articles

Prevalence of potentially pathogenic and antimicrobial-resistant Escherichia coli in raw milk and dairy products in Egypt

Milk and dairy products are popular in Egyptian diets, but their contamination with Escherichia coli, poses health risks. This study investigated the prevalence of potentially pathogenic and antimicrobial-resistant E. coli in raw milk and dairy products from Kafrelsheikh and Algarbia Governorates, Egypt. Two hundred ten samples including raw buffalo milk, goat milk, Domiati cheese, Domiati cheese with pepper, rayeb, and yogurt were analyzed. The prevalence of E. coli was 26.2%, with the highest occurrence in buffalo milk (68.0%) and the lowest in rayeb (7.5%). Based on ERIC-PCR, eighty-four non-clonal E. coli isolates were selected and further characterized. Among tested virulence genes, adhesion genes such as lpfAO113 and ehaA, were the most prevalent. Toxin-encoding genes such as astA, cdt, cnf, and hlyA were also detected. The cytotoxic and hemolytic activity of cdt, cnf, and hylA carrying E. coli were confirmed on CHO cells and sheep blood agar, respectively. Twenty-three (27.4%) isolates showed resistance to one or more antimicrobials, and 10 (11.9%) isolates exhibited multidrug resistance (MDR). Among 12 antimicrobials tested resistance against ampicillin, streptomycin and tetracycline was the highest. Phylogenetic analysis and O-genotyping indicated clinically significant isolates such as Og103, Og157 and OgGp9. Notably, two OgGp9 isolates were OgGp9:Hg18 and phylogenetic group D, like those associated with a large diarrheal outbreak caused by milk consumption in Japan, in 2021. Interestingly, these two isolates harbored a complete type 3 secretion system 2 locus (ETT2) and one of these isolates was MDR. These findings indicate that these dairy products were contaminated with potentially pathogenic and multidrug-resistant E. coli. This is the first report to analyze E. coli contamination in Domiati cheese with pepper and detect OgGp9:Hg18 outbreak-associated strains with ETT2 and MDR in Egypt.

Quantification of toxic metals contamination and health risk assessment in processed and raw dairy products in Abbottabad city

Toxic metal contamination (such as Cd, Cr and Pb) in processed and raw dairy products is an important environmental and public health concern. The accumulation of these metals in dairy products causes health threats to consumers. Various anthropogenic and natural activities discharge metals into the soil, where they are consumed by plants and become a part of the food chain. In addition, there is a considerable risk of metal contamination in dairy products during various business processes. The present study was carried out to determine the quantities of toxic metals found in dairy product samples. These dairy products have been classified into two groups: raw dairy products, which were self-extracted from cows and buffaloes employing adequate hygiene, and processed dairy products, which were bought from the Abbottabad market. These samples were generated using a double acid digestion approach, and toxic metals were quantified using atomic absorption spectrophotometry (AAS). For health risk assessment, the Health Risk Index (HRI), Target Hazard Quotient (THQ), and the Target Cancer Risk (TCR) indices were used. The relative levels of toxic metals in processed dairy product samples were as follows: Cd levels were highest in cheese (0.106±0.006 mg/kg), followed by butter and desi ghee (0.089±0.066 and 0.074±0.043 mg/kg, respectively). Cr concentrations were maximum in flavored milk (0.471± 0.290 mg/kg) and desi ghee (0.371± 0.01 mg/kg). Pb levels found in cheese were higher (1.753±0.194 mg/kg), then desi ghee and butter (1.025±0.01 and 0.652±0.397 mg/kg, respectively). Toxic metals in raw dairy products were measured in cow samples in the order of Cr ≥ Pb ≥ Cd. In a similar manner for buffalo samples, toxic metals followed the same trend as in cow samples. Though the concentrations of targeted metals in both raw and processed dairy product samples exceeded the threshold levels, the estimated levels of THQ and TCR were within the permissible range. However, our findings suggest that these metals in dairy products should be assessed on a continuous basis, as anthropogenic activities are contributing substantially to metal contamination.

Challenges and opportunities for risk- and systems-based control of Listeria monocytogenes transmission through food.

Listeria monocytogenes contamination of ready-to-eat (RTE) food products and food-associated built environments (e.g., processing facilities) represents a food safety issue with major public health and business risk implications. A number of factors make L. monocytogenes control a particular challenge, including (i) its frequent presence in different environments, (ii) its propensity for establishing persistence in food-associated environments, (iii) its ability to grow under a variety of stressful conditions, and (iv) its ability to cause severe illness, particularly in immunocompromised individuals and pregnant people. Key sources of L. monocytogenes contamination of RTE foods are food-associated built environments. However, raw materials can also be an important source, particularly for products without a "kill step" (e.g., fresh produce, raw dairy products, cold-smoked seafood). While certain RTE foods (e.g., deli meats, soft cheeses, produce) have commonly been linked to listeriosis outbreaks, cases, and recalls, a number of factors will influence the specific public health risk a given RTE food represents, including the likelihood of contamination, ability to support L. monocytogenes growth, and consumer-related factors (including consumption by pregnant or immunocompromised individuals). Consequently, a risk-based approach presents the most appropriate strategy to minimize the public health and business impact of L. monocytogenes. Key challenges to control L. monocytogenes include (i) development and implementation of food safety systems that prevent L. monocytogenes persistence in food-associated built environments, (ii) minimizing L. monocytogenes contamination of raw material sources, (iii) implementation of effective root cause analysis procedures, (iv) minimizing L. monocytogenes growth in finished product, and (v) consumer education.

Seroprevalence of Toxoplasma gondii and Associated Risk Factors in Pregnant Women in Araçatuba, São Paulo, Brazil: A Multi-Level Analysis.

This study assessed the seroprevalence of Toxoplasma gondii and risk factors among 428 pregnant women attending Basic Health Units (BHUs) in Araçatuba, São Paulo, Brazil. The seroprevalence was 55.14%, indicating high exposure to the parasite in this population. Using a multi-level logistic regression model, this study analyzed these predictors to determine their association with a higher seropositivity rate, with BHUs included as a random factor. Predictors associated with higher seropositivity included older age (36-45 years), with a 71.64% prevalence in this group, and multiparity (61.65%). Women with lower educational levels were also more likely to be infected, with 59.46% seropositivity recorded among those who had only completed elementary school. Despite identifying several risk factors, no significant correlation was found between undercooked meat consumption or contact with soil and infection. These findings highlight the need for targeted public health interventions, particularly for educating high-risk groups about toxoplasmosis prevention, such as safe food handling and avoiding raw dairy products. Additionally, BHUs play a critical role in early detection and prevention. These units are important for providing healthcare access and preventive education for vulnerable populations. Given the high seroprevalence, this study underscores the urgency of implementing prenatal screening and educational programs to reduce the risks of congenital toxoplasmosis in this region.

Prevalence, antimicrobial resistance, virulence gene distribution and SCCmec typing of methicillin-resistant Staphylococcus aureus isolated from raw milk and dairy products.

Researchers have focused on Staphylococcus aureus because it is transmitted through food, such as milk and dairy products, and causes human diseases. Prevalence, antimicrobial resistance, presence, and distribution of methicillin-resistant S. aureus (MRSA) virulence genes isolated from raw milk and dairy products were evaluated. 300 samples of dairy products were collected from Shahrekord, Iran. S. aureus was identified using biochemical tests and screened for sensitivity to 13 antibiotics to identify resistance genes. In addition, SCCmec typing was performed. Out of 300, S. aureus was found in 82 samples. Raw milk had the highest contamination with S. aureus (60 of 82), followed by cheese (15 of 82), and butter (7 of 82). At least one resistance gene was present in every isolate of S. aureus. Virulence factors and enterotoxin-coding genes, such as sea, seb, sec, and sed were highly distributed. The results of this study revealed the presence of toxin-producing MRSA strains in raw milk and dairy products. MRSA in dairy farms is an important risk factor for the spread of staphylococcal infections; therefore, further studies are needed to find strategies for controlling the presence of S. aureus, especially MRSA, in dairy products.

Analysis of the zoonotic tick-borne encephalitis virus (TBEV) in raw milk and dairy products in mountain pastures of the Lombardy region, Italy.

Over the last few decades, tick-borne encephalitis (TBE) has become a growing public health problem in Europe. The tick-borne encephalitis virus (TBEV) is a zoonotic virus that affects the central nervous system (CNS). TBEV has been detected in 27 European countries, and the rise in TBE cases is mainly due to environmental and ecological factors, and factors that increase the risk of human exposure to infected ticks. The infection via the alimentary route is the second most common means of TBEV transmission to humans. Raw milk from infected goats, sheep, or cows has been identified as a source of human food-borne infections. This study aims to gather new information on the prevalence of tick-borne encephalitis virus (TBEV) in raw goat's and cow's milk and related raw products in the Lombard Alps (Italy). This is important due to the close proximity of Lombardy to the Triveneto region, where TBE is endemic, and southern Switzerland, where numerous TBEV-positive mammals have been found. Throughout 2023, a passive monitoring plan was implemented on samples delivered for TBEV analyses from the Alpine pastures. In total, 248 specimens including raw milk, raw milk cheese, and butter were tested. This is the first monitoring of food at risk of TBEV transmission in a non-endemic region with evidence of TBEV circulation. Despite testing a wide range of dairy products, no sample tested positive for RNA-TBEV by real-time RT-PCR. Preliminary results suggest that raw milk and raw dairy products do not pose a significant risk of TBEV transmission to humans in the territory of Lombardy.

Antimicrobial resistance and prevalence of Listeria species from raw milk and dairy products in Burdur, Turkey.

Worldwide, but especially in emerging nations, concerns about food safety pose a serious obstacle to societal and economic progress. This research aimed to examine the prevalence of Listeria spp. in raw milk and dairy products in Burdur, as well as the presence of genes associated with biofilm formation and antibiotic resistance in the isolates. A total of 185 samples, including raw milk, curd, cream, butter, yogurt and cheese, were randomly collected in Burdur. The enrichment and isolation methods specified by the United States Department of Agriculture was used to identify Listeria species in milk and dairy product samples. Culture-positive strains were identified as Listeria genus and as species by PCR. Antibiotic susceptibility of the isolates was evaluated against 14 antibiotics using the disc diffusion technique (EUCAST). Of them, 2.2% (4/185) were positive for Listeria spp. Listeria species were isolated from cheese and yogurt samples. Two of them were Listeria innocua 1.1% (2/185), one was Listeria ivanovii 0.5% (1/185) and the other was Listeria welshimeri 0.5% (1/185). As a result of multiplex PCR of the biofilm genotypic marker luxS and flaA genes, the flaA gene was detected in three of four isolates, the luxS gene was detected in one isolate, and these two genes were not found in one isolate. Although all isolates were resistant to gentamicin and rifampicin, they also showed multidrug resistance. This study revealed that the diversity of prevalence of Listeria spp. in Burdur requires microbial risk assessment in the milk and dairy products value chain and the need to focus on the problem of multiple antibiotic resistance.

Monitoring Changes in the Antimicrobial-Resistance Gene Set (ARG) of Raw Milk and Dairy Products in a Cattle Farm, from Production to Consumption.

Raw milk and dairy products can serve as potential vectors for transmissible bacterial, viral and protozoal diseases, alongside harboring antimicrobial-resistance genes. This study monitors the changes in the antimicrobial-resistance gene pool in raw milk and cheese, from farm to consumer, utilizing next-generation sequencing. Five parallel sampling runs were conducted to assess the resistance gene pool, as well as phage or plasmid carriage and potential mobility. In terms of taxonomic composition, in raw milk the Firmicutes phylum made up 41%, while the Proteobacteria phylum accounted for 58%. In fresh cheese, this ratio shifted to 93% Firmicutes and 7% Proteobacteria. In matured cheese, the composition was 79% Firmicutes and 21% Proteobacteria. In total, 112 antimicrobial-resistance genes were identified. While a notable reduction in the resistance gene pool was observed in the freshly made raw cheese compared to the raw milk samples, a significant growth in the resistance gene pool occurred after one month of maturation, surpassing the initial gene frequency. Notably, the presence of extended-spectrum beta-lactamase (ESBL) genes, such as OXA-662 (100% coverage, 99.3% identity) and OXA-309 (97.1% coverage, 96.2% identity), raised concerns; these genes have a major public health relevance. In total, nineteen such genes belonging to nine gene families (ACT, CMY, EC, ORN, OXA, OXY, PLA, RAHN, TER) have been identified. The largest number of resistance genes were identified against fluoroquinolone drugs, which determined efflux pumps predominantly. Our findings underscore the importance of monitoring gene pool variations throughout the product pathway and the potential for horizontal gene transfer in raw products. We advocate the adoption of a new approach to food safety investigations, incorporating next-generation sequencing techniques.

Risk Assessment of AFM1 in Raw Milk and Dairy Products Produced in Armenia, a Caucasus Region Country: A Pilot Study.

This paper presents the first assessment of dietary exposure to aflatoxin M1 (AFM1) and associated health risks through milk and dairy product consumption in Armenia. Data on AFM1 in raw milk were obtained from an annual residue monitoring program. Additionally, commonly consumed dairy products (pasteurized milk, cheese, sour cream, curd cheese) were sampled, considering the sources of raw milk used by dairy companies. Per capita consumption of raw milk was sourced from national food balance databases, while individual consumption data for dairy products was collected via a 24 h recall survey with 1400 adult respondents. Detectable levels of AFM1 were observed in 7.14% of raw milk samples (up to 0.334 μg/kg) and, albeit at lower amounts (up to 0.009 µg/kg), in 30% and 40% of sour cream and curd cheese, respectively. The AFM1 levels were lower than the national maximum permitted level (0.5 μg/kg); however, levels in raw milk exceeded the EU ML (0.05 μg/kg). The estimated margin of exposure values for dairy products indicated no significant risk, whereas a reasonable worst-case estimate, using the measurable levels of AFM1 in raw milk consumption indicated a potential public health concern. This study provides a scientific basis for evaluating aflatoxin issues in the Caucasus area.

Occurrence and diversity of Listeria monocytogenes in Portuguese dairy farms

Listeria monocytogenes is a pathogenic microorganism that causes listeriosis, an infection that usually occurs after consumption of contaminated food and is considered particularly dangerous due to its ability to grow and multiply under adverse conditions. In recent years, there has been an increase in the consumption of unprocessed products, such as raw milk and dairy products, by people of all ages, including those with compromised immune systems, which could lead to an increase in foodborne illness. Ruminants play a very important role in the persistence and transmission of L. monocytogenes through a continuous oral-faecal cycle. Therefore, farms are considered a reservoir of this microorganism and are involved in the transmission from animals to humans. In this study, samples of faeces, milk, water, silage, feed and teat cups swabs were collected from 8 farms to assess the distribution of the pathogen in the farm environment. Milk samples were also collected from 100 dairy farms to assess the risk associated with the consumption of raw milk. Detection was performed by real-time PCR, while preparation, enrichment and confirmation were performed according to ISO 11290–1, (2017). The prevalence in water was 8.3%, in faeces 12.5% and in feed 12.0%, while in the other samples the microorganism was not detected. It was also observed that this microorganism was more abundant in spring months. The eight isolates were serotyped by real-time PCR and the most frequent serogroup was IVb with 5 isolates (2 of which were IVb-v1) and the remaining 3 were IIb. Two of the clonal complexes (CCs) identified were shared by two isolates (CC 213 and CC 217), the remaining CCs identified (CC 392, CC 554, CC 489, CC 224 and CC 183) were not identified in more than one isolate. This study contributed to a better understanding of the ecology of L. monocytogenes in dairy farms, showing that most of the clones found in food were not present in this environment and that genes coding for disinfectants and heavy metals were not detected.

Structural analysis of cattle enterprises in Kayapinar district of Diyarbakır province

This research was conducted in person in Diyarbakir province, Kayapınar district, by means of a questionnaire with a total of 120 people engaged in cattle breeding in 21 settlements. The questionnaire addresses the existence of cattle farms, the general structural status of cattle farms, information provided by owners, feed supply and feeding practices, animal health and treatment practices, reproduction and artificial insemination practices, production and marketing of animal products on farms, housing status and support utilization status. It has been shown that the farms are small farms and 92% of the farms have closed barns. The fact that the majority of farm owners are between 40 and 61 years old can be seen as a danger signal for livestock. It was found that there is no cooperative in the villages except Cumhuriyet district, which brings the problem of marketing raw milk and dairy products. In the study area, it it has been observed that activities such as animal care feeding, estrus monitoring and application, and automation in animal husbandry are insufficient. For sustainable animal production, relevant public institutions and organizations need to work more intensively and carry out training, monitoring and evaluation activities to increase productivity per animal in enterprises, to train operators on herd management, care and feeding and animal health, and to meet expectations by solving problems in enterprises. This research provides us with important data about the general structure of cattle breeding in Kayapınar district of Diyarbakır province.

Diverse Genotypes of Cronobacter spp. Associated with Dairy Farm Systems in Jiangsu and Shandong Provinces in China.

Cronobacter spp. are the most concerning foodborne pathogen in infant formula milk powder. Currently, there are many reports on the prevalence of Cronobacter spp. in infant formula milk and its processing environment, but there are few studies on the prevalence of Cronobacter spp. on dairy farms. We have, therefore, undertaken this study to investigate and track genomic epidemiology of Cronobacter spp. isolates from Chinese dairy farms in the provinces of Jiangsu and Shandong. In this study, forty Cronobacter spp. strains, consisting of thirty Cronobacter sakazakii, eight Cronobacter malonaticus, and two Cronobacter dublinensis, were obtained from 1115 dairy farm samples (raw milk, silage, bedding, and feces), with a prevalence rate of 3.57%. These isolates were classified into 10 Cronobacter serotypes and 31 sequence types (STs), including three novel STs which were isolated for the first time. Notably, pathogenic Cronobacter STs 7, 8, 17, 60, and 64, which are associated with clinical infections, were observed. Antimicrobial susceptibility testing showed that all the Cronobacter spp. were highly resistant to cephalothin and fosfomycin, which was consistent with the antimicrobial genotype. All isolates carried core virulence genes related to adherence, invasion, endotoxin, immune evasion, secretion system, and regulation. Approximately half the isolates were also able to produce a strong biofilm. Twenty-one prophages and eight plasmids were detected, with the most common prophage being Cronobacter_ENT47670 and the most common plasmid being IncFIB (pCTU1). In addition, two isolates harbored the transmissible locus of stress tolerance (tLST) which confers high environmental persistence. Phylogenetic analysis showed strong clustering by species level and sequence types. Isolates from different sources or regions with a similar genomic background suggests the cross-contamination of Cronobacter spp. The presence of diverse genotypes of Cronobacter spp. in dairy farms in Jiangsu and Shandong provinces indicates that surveillance of Cronobacter spp. on dairy farms should be strengthened, to prevent and control transmission and ensure the quality and safety of raw dairy products.

Legal regulation of the state supply of milk, dairy raw materials and dairy products

The paper establishes that in the legal field of Ukraine there are more than 50 legal and regulatory acts that are directly or indirectly related to the regulation of the dairy industry market. The Law of Ukraine "On Milk and Dairy Products" is basic in the field of regulation of the dairy industry. The legislator fixed the interpretation of the main terms of the dairy industry in the relevant legal act - the Law of Ukraine "On Milk and Dairy Products". This act defines what "raw milk", "dairy raw materials", "dairy products", "traditional dairy products" are. Also, the legislator fixed the main institutions of the state policy of ensuring the safety and quality of milk and dairy products. In addition, the act discloses the issue of state support for producers of milk, dairy raw materials and dairy products and the mechanism for its implementation. It should be noted that the Law of Ukraine "On Milk and Dairy Products" regulates the legal and organizational foundations for ensuring the safety and quality of milk and dairy products for life and the health of the population and the environment during their production, transportation, processing, storage and sale, import into the customs territory and export from the customs territory of Ukraine. The study identified the main, in our opinion, regulatory legal acts that regulate the supply of milk, dairy raw materials and dairy products to the state, and also characterized their purpose, main provisions and meaning. It was found that milk and dairy products occupy a significant place in the market of food resources. It is noted that the production of dairy products is an important component of food security. It was found that providing the state with milk is a complex process that includes the following stages: milk production, milk processing, sale of dairy products, state regulation.

Biodiversity and antibiotic resistance profile provide new evidence for a different origin of enterococci in bovine raw milk and feces.

Enterococci are widely distributed in dairy sector. They are commensals of the gastrointestinal tract of animals, thus, via fecal contamination, could reach raw milk and dairy products. The aims of this study were: 1) to investigate the enterococcal diversity in cow feces and milk samples and 2) to evaluate the antibiotic resistance (AR) of dairy-related enterococci and their ability to transfer resistance genes.E. faecalis (59.9%), E. faecium (18.6%) and E. lactis (12.4%) were prevalent in milk, while E. faecium (84.2%) and E. hirae (15.0%) were dominant in bovine feces. RAPD-PCR highlighted a high number of Enterococcus biotypes (45 from milk and 37 from feces) and none of the milk strains exhibited genetic profiles similar to those of feces biotypes.A high percentage of enterococci isolated from milk (71%) were identified as multidrug resistant and resistance against streptomycin and tetracycline were widespread among milk strains while enterococci from feces were commonly resistant to linezolid and quinupristin/dalfopristin. Only E. faecalis strains were able to transfer horizontally the tetM gene to Lb. delbrueckii subsp. lactis. Our results indicated that Enterococcus biotypes from milk and bovine feces belong to different community and the ability of these microorganisms to transfer AR genes is strain-dependent.

Assessment of Listeria monocytogenes contamination and antibiotic resistance in raw milk samples collected from Colombo district Sri Lanka

Background: Listeria monocytogenes, a foodborne pathogen, poses a significant risk to public health due to its potential to cause severe infections termed “listeriosis”. Raw milk and dairy products are common vehicles for L. monocytogenes transmission, amplifying the risk to consumers. Additionally, the emergence of antibiotic resistance in Listeria strains heightens concerns in human and veterinary medicine. Aim: This study aimed to assess the prevalence of L. monocytogenes in raw milk samples from Sri Lanka’s Colombo district and to characterize the antibiotic resistance patterns of positive isolates. Methods: One hundred raw milk samples were collected from various milk collection centers. Samples were sourced from locations including Awissawella, Kahanthota, Meepe, Homagama, and Udahamulla. Antibiotic resistance was evaluated using standard methods like disk diffusion and well diffusion, testing ampicillin, penicillin, streptomycin, and tetracycline. Results: Of the 100 samples, L. monocytogenes was detected by conventional PCR in 83, with Awissawella having the highest occurrence (100%), followed by Kahanthota (81.81%), Meepe (81.48%), Homagama (77.27%), and Udahamulla (44.44%). Among the positive samples, 72 showed varying degrees of antibiotic resistance. The highest level of resistance was observed for penicillin (83.1%), followed by ampicillin (65%), streptomycin (32.53%), and tetracycline (10.84%). Sixty isolates (60%) displayed resistance to more than one antibiotic studied. Findings also revealed the widespread manual milking, predominant water usage over soap for hygiene, and common daily bathing of cows, highlighting the need for improved hygiene practices to minimize contamination risks in dairy farming. Conclusion: Raw milk contaminated with L. monocytogenes pose a serious public health risk. The study highlights the need for stringent hygiene measures in milk production and processing to safeguard consumers. Additionally, the high prevalence of antibiotic-resistant strains underscores the importance of judicious antibiotic use in both human and veterinary medicine to mitigate the further emergence and spread of resistant Listeria strains.

Screening of antibiogram, virulence factors, and biofilm production of Staphylococcus aureus and the bio-control role of some probiotics as alternative antibiotics.

Food safety is a serious challenge in the face of increasing population and diminishing resources. Staphylococcus aureus is a critical foodborne pathogen characterized by its capability to secret a diverse range of heat-resistant enterotoxins. Antibiotic usage in dairy herds resulted in the occurrence of antimicrobial resistance (AMR) patterns among bacterial species, which were consequently transmitted to humans via dairy products. Lactic acid bacteria (LAB) produce bacteriocins, which provide an excellent source of natural antimicrobials with the further advantage of being environmentally friendly and safe. Detection of multidrug resistance (MDR) S. aureus isolates in concerned samples, molecular characteristics, biofilm production, and the inhibitory role of LAB against it. Random samples of raw milk and other dairy products were analyzed for S. aureus isolation. Phenotypic and genotypic assessment of AMR was performed, in addition to detection of classical enterotoxin genes of S. aureus. Finally, evaluation of the antimicrobial action of some Lactobacillus strains against S. aureus. Incidence rates of presumptive S. aureus in raw milk, Kariesh cheese, and yogurt samples were 50%, 40%, and 60%, respectively. The highest resistance of S. aureus was to Kanamycin (100%) and Nalidixic acid (89.3%), respectively. (78.66%) of S. aureus were MDR. 11.1% of S. aureus carried mecA gene. In concern with enterotoxins genes, PCR showed that examined isolates harbored sea with a percentage of (22.2%), while sed was found in (11.1%) of isolates. Regarding biofilm production, (88.88%) of S. aureus were biofilm producers. Finally, agar well diffusion showed that Lactobacillus acidophilus had the strongest antimicrobial action against S. aureus with inhibition zone diameter ranging from 18 to 22 mm. There is a widespread prevalence of MDR S. aureus in raw milk and dairy products. Production of staphylococcal enterotoxins, as well as biofilm production are responsible for public health risks. Therefore, installing proper hygienic routines and harsh food safety policies at food chain levels is substantial.

Toxigenic Genes of Coagulase-Negative/Positive Staphylococcus aureus from Milk and Dairy

This study was performed to determine the prevalence of toxin-related genes and methicillin-resistance genes in coagulase-positive/negative Staphylococcus aureus isolated from raw milk and dairy products. The incidence of Staphylococcus aureus in tested 260 raw milk and 755 dairy samples was highest with ice cream (15.7%) followed by raw milk (11.2%), cheese (10.1%), and butter (2.7%) samples. The distribution of coagulase-positive and negative Staphylococcus aureus was 3.2% (33 isolates) and 5.3% (54 isolates) respectively. The average counts of Staphylococcus aureus among the dairy, positive samples were 3.46 and 3.16 log CFU/ml-g for coagulase-positive and negative isolates respectively. According to the results of Polymerase Chain Reaction, the enterotoxin gene sea (6.9%) was detected in milk and 5 cheese, seb (2.3%) in 2 cheese, see (1.1%) in a cheese isolate of coagulase-positive Staphylococcus aureus. One coagulase-negative Staphylococcus aureus isolated from milk possessed both tss and etb genes. None of the isolates had the sec, sed enterotoxin, pvl, eta virulence, and mecA methicillin resistance genes. As a result, enterotoxin genes were determined among coagulase-positive Staphylococcus aureus isolated from dairy products, while toxin genes associated with human infections were assigned in coagulase-negative Staphylococcus aureus isolates. Coagulase-negative Staphylococcus aureus strains are not considered in standard food surveillance analysis. These strains carrying toxigenic genes can be ingested with food and colonized in the gastrointestinal tract, and they can transfer their pathogenic genes to other strains and/or bacteria. Thus, it should be considered in terms of public health that staphylococci harboring toxin genes. Our work demonstrated the pathogenic potential of neglected bacteria coagulase-negative staphylococci carrying virulence genes. More research is needed about this bacteria implemented in the food matrix, and clinical isolates. In the future, surveillance of coagulase-negative Staphylococcus aureus in foods and human infections may be included food legislation rules.

Analytical Assessment of the System for Confirming Compliance of Milk and Dairy Products with Mandatory Legal Requirements

Introduction: The safety and quality of dairy products produced and in circulation on the territory of the EAEU is ensured by compliance with legislation on technical regulation, sanitary, hygienic and veterinary safety. One of the important sections of technical regulation is the rules for confirming product compliance with mandatory legal requirements.Purpose: The purpose of this review is analysis of the current legislative framework in the Russian Federation in the field of confirming compliance of milk and dairy products with the requirements of regulatory legal acts and systematization of the data obtained on the applicable forms assessing and confirming compliance of products in the Russian Federation. Materials and Methods: As materials for the analytical study were used regulatory legal acts (hereinafter - RLA) in the field of technical regulation, sanitary, hygienic and veterinary safety of food products and raw materials. The documents were obtained on the official legal portals of the Government of the Russian Federation, the Eurasian Economic Commission, the Ministry of Agriculture of the Russian Federation, the Ministry of Industry and Trade of the Russian Federation, the Ministry of Health of the Russian Federation. As a research method, the analysis of the current legislation with the subsequent systematization of expert opinions on the law enforcement practice of the regulated rules for products confirming conformity, generalization and analysis of the most common arbitration situations in the raw milk and finished dairy products turnover at the stage of their compliance with mandatory requirements confirming (assessment) were used. The appeals and documents of the technical regulation and standardization services of dairy industry enterprises on the subject research field were also analyzed.Results: Based on the regulated in RLA requirements for confirming (assessment) compliance of raw milk and dairy products, as well as based on the generalized results of a product manufacturers survey, have been established the conformity assessment schemes most often used by manufacturers. Taking into account the analysis and systematization of material on arbitration issues in confirming (assessment) compliance, recommendations are proposed for optimizing the process of confirming (assessment) compliance of raw milk and dairy products with the requirements of the legislation of the EAEU and the Russian Federation, including the feasibility of its updating.Conclusion: According to the results of the research have been identified a number of problems in the field of confirming (assessment) of milk and dairy products compliance with the requirements of the RLA, which producers and regulatory authorities bodies in their professional activities, and appropriate solutions to these problems have been proposed.

Contamination of Plant Foods with Bacillus cereus in a Province and Analysis of Its Traceability.

Bacillus cereus is an important zoonotic foodborne conditional pathogen. It is found in vegetables, dairy products, rice, and other foods, thereby greatly endangering human health. Investigations on B. cereus contamination in China primarily focus on raw milk, dairy products, meat, and others, and limited research has been conducted on plant-based foodstuffs. The rapid development of sequencing technology and the application of bioinformatics-related techniques means that analysis based on whole-genome sequencing has become an important tool for the molecular-epidemiology investigation of B. cereus. In this study, we investigated the contamination of B. cereus in six types of commercially available plant foods from eight regions of a province. The molecular epidemiology of the isolated B. cereus was analyzed by whole-genome sequencing. We aimed to provide fundamental data for the surveillance and epidemiology analysis of B. cereus in food products in China. The rapid traceability system of B. cereus established in this study can provide a basis for rapid molecular epidemiology analysis of B. cereus, as well as for the prevention and surveillance of B. cereus. Moreover, it can also be expanded to monitoring and rapid tracing of more foodborne pathogens.

Lead and Cadmium Concentrations in Raw Milk and Dairy Products in Zanjan, Iran: A Study on Winter and Summer Variations

Lead and Cadmium Concentrations in Raw Milk and Dairy Products in Zanjan, Iran: A Study on Winter and Summer Variations