Search Results (2,946)

Multiple microbial detections in stool samples of indigenous individuals suffering from chronic gastroenteric disorder of a likely infectious origin, characterized by recurring diarrhea of variable intensity, in the rural north-east of Colombia are common findings, making the assignment of etiological relevance to individual pathogens challenging. In a population of 773 indigenous people from either the tribe Wiwa or Kogui, collider bias analysis was conducted comprising 32 assessed microorganisms including 10 bacteria (Aeromonas spp., Campylobacter spp., enteroaggregative Escherichia coli (EAEC), enteropathogenic Escherichia coli (EPEC), enterotoxigenic Escherichia coli (ETEC), Salmonella spp., Shiga toxin-producing Escherichia coli (STEC), Shigella spp./enteroinvasive Escherichia coli (EIEC), Tropheryma whipplei and Yersinia spp.), 11 protozoa (Blastocystis spp., Cryptosporidium spp., Cyclospora spp., Dientamoeba fragilis, Entamoeba coli, Entamoeba bangladeshi/dispar/histolytica/moshkovskii complex, Entamoeba histolytica, Endolimax nana, Giardia duodenalis, Iodamoeba buetschlii and Pentatrichomonas hominis), 8 helminths (Ascaris spp., Enterobius vermicularis, Hymenolepis spp., Necator americanus, Schistosoma spp., Strongyloides spp., Taenia spp. and Trichuris spp.), microsporidia (Encephalocytozoon spp.) and fungal elements (microscopically observed conidia and pseudoconidia). The main results indicated that negative associations potentially pointing towards collider bias were infrequent events (n = 14), while positive associations indicating increased likelihood of co-occurrence of microorganisms quantitatively dominated (n = 88). Microorganisms showing the most frequent negative associations were EPEC (n = 6) and Blastocystis spp. (n = 3), while positive associations were most common for Trichuris spp. (n = 16), Dientamoeba fragilis (n = 15), Shigella spp./EIEC (n = 12), Ascaris spp. (n = 11) and Blastocystis spp. (n = 10). Of note, positive associations quantitively dominated for Blastocystis spp. In conclusion, collider bias assessment did not allow clear-cut assignment of etiological relevance for detected enteric microorganisms within the assessed Colombian indigenous population. Instead, the results suggested complex microbial interactions with potential summative effects. Future studies applying alternative biostatistical approaches should be considered to further delineate respective interactions. Full article

Although biofilms contribute to bacterial tolerance to desiccation and survival in low-moisture foods, the molecular mechanisms underlying biofilm formation have not been fully understood. This study created a mutant library from Salmonella Enteritidis using mini-Tn10 transposon mutagenesis. The biofilm-forming potential of acquired mutants was assessed before the genomic DNA of the mutants that formed significantly (p ≤ 0.05) less biofilm mass than their wildtype parent strain was extracted for deep DNA sequencing. The gene of each mutant interrupted by mini-Tn10 insertion was identified by aligning obtained sequencing data with the reference Genbank sequences using a BLAST search. Sixty-four mutant colonies were selected, and five mutants that formed the least amount of biofilm mass compared to the wildtype parent strain were selected for sequencing analysis. The results of the BLAST search revealed that the gene interrupted by mini-Tn10 in each mutant is responsible for the biosynthesis of aldehyde dehydrogenase (EutE), cysteine desulfurase (SufS or SufE), a transporter protein, porin OmpL, and a ribbon–helix–helix protein from the CopG family, respectively. Knock-off mutant construction is a possible approach to verify the potential of the identified genes to serve as targets of antimicrobial intervention to control Salmonella colonization on low-moisture foods and in their production environment. Full article

The microbiological quality of dairy products from small-scale producers in Serbia was analysed. A total of 302 dairy products [raw (n = 111) and pasteurized milk cheeses (n = 79) and kajmak (n = 112)], were collected and tested for the presence of pathogens, Listeria monocytogenes and Salmonella spp., and enumerated for Coagulase-positive staphylococci (CPS), Escherichia coli, and yeasts and moulds. None of the samples tested positive for Salmonella spp., while L. monocytogenes was recovered from one raw milk cheese and five kajmak samples. Raw milk cheese and kajmak also had higher levels of indicator microorganisms, namely E. coli and yeast and moulds. Molecular serotyping grouped L. monocytogenes isolates into serogroups 1 (1/2a and 3a) and 3 (1/2b, 3b, and 7). When exposed to eight antibiotics, L. monocytogenes isolates were mostly sensitive, with the exception of oxacillin and reduced susceptibility to clindamycin, penicillin G, and trimethoprim/sulfamethoxazole, emphasizing the importance of continuous surveillance for antimicrobial resistance. Samples that tested positive for Listeria spp. also had higher loads of indicator microorganisms, namely E. coli and yeast and moulds, suggesting lapses in hygiene practices during production. Collectively, these data emphasize the need for improved food safety and hygiene practices among small-scale dairy producers. This is crucial to reduce the microbial contamination and improve both the quality and safety of dairy products in the Serbian market. Full article

Cancer patients face increased susceptibility to invasive infections, primarily due to ulcerative lesions on mucosal surfaces and immune suppression resulting from chemotherapy. Pseudomonas aeruginosa (P. aeruginosa) bacteremia is notorious for its rapid progression into fatal sepsis, posing a significant threat to cancer patients, particularly those experiencing chemotherapy-induced neutropenia. This bacterial infection contributes significantly to morbidity and mortality rates among such individuals. Our latest report showed the mutually beneficial effects of postbiotic butyrate on 1,25-dihydroxyvitamin D3 (1,25D3)-controlled innate immunity during Salmonella colitis. Hence, we investigated the impact of butyrate and 1,25D3 on chemotherapy-induced gut-derived P. aeruginosa sepsis in mice. The chemotherapy-induced gut-derived P. aeruginosa sepsis model was established through oral administration of 1 × 10⁷ CFU of the P. aeruginosa wild-type strain PAO1 in C57BL/6 mice undergoing chemotherapy. Throughout the infection process, mice were orally administered butyrate and/or 1,25D3. Our observations revealed that the combined action of butyrate and 1,25D3 led to a reduction in the severity of colitis and the invasion of P. aeruginosa into the liver and spleen of the mice. This reduction was attributed to an enhancement in the expression of defensive cytokines and antimicrobial peptides within the cecum, coupled with decreased levels of zonulin and claudin-2 proteins in the mucosal lining. These effects were notably more pronounced when compared to treatments administered individually. This study unveils a promising alternative therapy that involves combining postbiotics and 1,25D3 for treating chemotherapy-induced gut-derived P. aeruginosa sepsis. Full article

Pleopeltis crassinervata is a fern documented in ethnobotanical records for its use in Mexican traditional medicine to treat gastric disorders and mouth ulcers. Consequently, conducting biological and pharmacological assays is crucial to validate the therapeutic efficacy of this plant within the context of traditional medicine. In the present study, we investigated the biological activity of extracts and fractions obtained from P. crassinervata organs against bacteria (Salmonella typhimurium, Salmonella typhi, Staphylococcus aureus, Proteus mirabilis, Shigella flexneri, Bacillus subtilis, Escherichia coli) and Trichomonas vaginalis using in vitro models. The precipitate fraction obtained from the frond methanolic extract showed significant antibacterial activity (minimal inhibitory concentration [MIC] 120 µg/mL) against the Staphylococcus aureus strain and was effective against both Gram-positive and Gram-negative bacteria. The hexane fraction also obtained from frond methanolic extract, showed a trichomonacidal effect with an IC₅₀ of 82.8 μg/mL and a low cytotoxic effect. Hsf6 exhibited the highest activity against T. vaginalis, and the GC-MS analysis revealed that the predominant compound was 16-pregnenolone. The remaining identified compounds were primarily terpene-type compounds. Full article

The presence of enteric pathogens in produce can serve as a significant means of transmitting infections to consumers. Notably, tomatoes, as a type of produce, have been implicated in outbreaks caused by various human pathogens, such as Salmonella enterica and pathogenic Escherichia coli. However, the survival characteristics of Shigella spp. in tomatoes have not been thoroughly investigated. In this study, we assess the survival of S. flexneri 2a in two distinct varieties of post-harvested tomatoes. S. flexneri 2a was used to inoculate both regular-sized Vine tomatoes and cherry-type Mini Plum tomatoes. Our findings reveal no significant difference in Shigella survival in the pericarp of both varieties on day 2 post-inoculation. However, a significant disparity emerges on day 6, where all recovered Shigella colonies exclusively belong to the Mini Plum variety, with none associated with the Vine type. When Shigella was inoculated into the locular cavity (deep inoculation), no significant difference between varieties was observed. Additionally, we investigate the potential role of the SRL pathogenicity island (SRL PAI) in the survival and fitness of S. flexneri 2a in post-harvested tomatoes. Our results indicate that while the SRL PAI is not linked to the survival of the strains in tomato, it does impact their fitness. These findings underscore the variability in Shigella strains’ survival capabilities depending on the tomato variety, highlighting the importance of understanding Shigella ecology beyond the human host and identifying molecular determinants influencing bacterial survival to mitigate the risk of future outbreaks. The significance of this data on Shigella persistence in fresh vegetables should not be underestimated, as even a small number of Shigella cells can pose a threat to the health of individuals. Full article

This review delves into using natural antimicrobials in the dairy industry and examines various sources of these compounds, including microbial, plant, and animal sources. It discusses the mechanisms by which they inhibit microbial growth, for example, by binding to the cell wall’s precursor molecule of the target microorganism, consequently inhibiting its biosynthesis, and interfering in the molecule transport mechanism, leading to cell death. In general, they prove to be effective against the main pathogens and spoilage found in food, such as Escherichia coli, Staphylococcus aureus, Bacillus spp., Salmonella spp., mold, and yeast. Moreover, this review explores encapsulation technology as a promising approach for increasing the viability of natural antimicrobials against unfavorable conditions such as pH, temperature, and oxygen exposure. Finally, this review examines the benefits and challenges of using natural antimicrobials in dairy products. While natural antimicrobials offer several advantages, including improved safety, quality, and sensory properties of dairy products, it is crucial to be aware of the challenges associated with their use, such as potential allergenicity, regulatory requirements, and consumer perception. This review concludes by emphasizing the need for further research to identify and develop effective and safe natural antimicrobials for the dairy industry to ensure the quality and safety of dairy products for consumers. Full article

Bacitracin Methylene Disalicylate (BMD), as a feed additive to poultry diets, enhances digestion, prevents Salmonella enteritidis (SE) colonization, and treats current infections. The objective of this study was to utilize a quantitative proteomic approach to determine the effect of BMD feed additive on broiler chickens challenged with SE in the spleen proteome. At 1 d of age, chicks were randomly allocated into four groups: control with and without SE challenge (CON, n = 60; CON-SE, n = 60), BMD with and without SE challenge (BMD, n = 60; BMD-SE, n = 60). Birds in the CON-SE and BMD-SE treatment were administered SE inoculum by oral gavage. On day three and day seven post-gavage, the spleen was collected aseptically from birds in each treatment group (CON, n = 4/day; CON-SE, n = 4/day; BMD, n = 4/day; BMD-SE, n = 4/day). Proteomic analysis by liquid chromatography-tandem mass spectrometry (LC-MS/MS) showed an increased abundance of 115 proteins and decreased of 77 due to the BMD. Proteins that decreased in abundance were enriched for fibrinogen complex and extracellular space, whereas proteins that increased in abundance were enriched for proteasome-mediated ubiquitin-dependent protein catabolic process and mitochondrion. Analysis of the interaction between BMD and the Salmonella challenge found 230 differentially abundant proteins including proteins associated with RNA binding, spliceosome, protein transport, and cell adhesion among the upregulated proteins, and those associated with protein folding, carbon metabolism, biosynthesis of nucleotide sugars, response to oxidative stress, positive regulation of NIK/NF-kappaB signaling, and inflammatory response among the downregulated proteins. The impact of BMD treatment on spleen proteome indicates an anti-apoptotic effect. BMD also modified the response of the spleen to the SE challenge with a marked decrease in proteins that prompt cytokine synthesis and an increase in proteins involved in the selective removal of unfolded proteins. Full article

In contrast to “frank” pathogens, like Salmonella entrocolitica, Shigella dysenteriae, and Vibrio cholerae, that always have a probability of disease, “opportunistic” pathogens are organisms that cause an infectious disease in a host with a weakened immune system and rarely in a healthy host. Historically, drinking water treatment has focused on control of frank pathogens, particularly those from human or animal sources (like Giardia lamblia, Cryptosporidium parvum, or Hepatitis A virus), but in recent years outbreaks from drinking water have increasingly been due to opportunistic pathogens. Characteristics of opportunistic pathogens that make them problematic for water treatment include: (1) they are normally present in aquatic environments, (2) they grow in biofilms that protect the bacteria from disinfectants, and (3) under appropriate conditions in drinking water systems (e.g., warm water, stagnation, low disinfectant levels, etc.), these bacteria can amplify to levels that can pose a public health risk. The three most common opportunistic pathogens in drinking water systems are Legionella pneumophila, Mycobacterium avium, and Pseudomonas aeruginosa. This report focuses on these organisms to provide information on their public health risk, occurrence in drinking water systems, susceptibility to various disinfectants, and other operational practices (like flushing and cleaning of pipes and storage tanks). In addition, information is provided on a group of nine other opportunistic pathogens that are less commonly found in drinking water systems, including Aeromonas hydrophila, Klebsiella pneumoniae, Serratia marcescens, Burkholderia pseudomallei, Acinetobacter baumannii, Stenotrophomonas maltophilia, Arcobacter butzleri, and several free-living amoebae including Naegleria fowleri and species of Acanthamoeba. The public health risk for these microbes in drinking water is still unclear, but in most cases, efforts to manage Legionella, mycobacteria, and Pseudomonas risks will also be effective for these other opportunistic pathogens. The approach to managing opportunistic pathogens in drinking water supplies focuses on controlling the growth of these organisms. Many of these microbes are normal inhabitants in biofilms in water, so the attention is less on eliminating these organisms from entering the system and more on managing their occurrence and concentrations in the pipe network. With anticipated warming trends associated with climate change, the factors that drive the growth of opportunistic pathogens in drinking water systems will likely increase. It is important, therefore, to evaluate treatment barriers and management activities for control of opportunistic pathogen risks. Controls for primary treatment, particularly for turbidity management and disinfection, should be reviewed to ensure adequacy for opportunistic pathogen control. However, the major focus for the utility’s opportunistic pathogen risk reduction plan is the management of biological activity and biofilms in the distribution system. Factors that influence the growth of microbes (primarily in biofilms) in the distribution system include, temperature, disinfectant type and concentration, nutrient levels (measured as AOC or BDOC), stagnation, flushing of pipes and cleaning of storage tank sediments, and corrosion control. Pressure management and distribution system integrity are also important to the microbial quality of water but are related more to the intrusion of contaminants into the distribution system rather than directly related to microbial growth. Summarizing the identified risk from drinking water, the availability and quality of disinfection data for treatment, and guidelines or standards for control showed that adequate information is best available for management of L. pneumophila. For L. pneumophila, the risk for this organism has been clearly established from drinking water, cases have increased worldwide, and it is one of the most identified causes of drinking water outbreaks. Water management best practices (e.g., maintenance of a disinfectant residual throughout the distribution system, flushing and cleaning of sediments in pipelines and storage tanks, among others) have been shown to be effective for control of L. pneumophila in water supplies. In addition, there are well documented management guidelines available for the control of the organism in drinking water distribution systems. By comparison, management of risks for Mycobacteria from water are less clear than for L. pneumophila. Treatment of M. avium is difficult due to its resistance to disinfection, the tendency to form clumps, and attachment to surfaces in biofilms. Additionally, there are no guidelines for management of M. avium in drinking water, and one risk assessment study suggested a low risk of infection. The role of tap water in the transmission of the other opportunistic pathogens is less clear and, in many cases, actions to manage L. pneumophila (e.g., maintenance of a disinfectant residual, flushing, cleaning of storage tanks, etc.) will also be beneficial in helping to manage these organisms as well. Full article

Salmonella enterica ser. Enteritidis (S. Enteritidis) is widely found in chickens and eggs, and it can potentially induce human illness. The investigation in this study centers on the impacts of long-term dietary supplementation with coated sodium butyrate (CSB) on intestinal well-being and the colonization of cecum Salmonella in laying hens infected with S. Enteritidis. We segregated a total of 120 Lohmann laying hens aged 51 weeks into four treatment categories: 0 (CON), 300 (CSB1), 500 (CSB2), and 800 (CSB3) mg/kg of CSB, supplemented with CSB from the first day of the experiment. A 24-week observation process was carried out for each laying hen. The S. Enteritidis was orally administered to all chickens on the morning of the first and third days of week 22 of the trial. After the S. Enteritidis challenge, egg production decreased the most in the CON group. Compared to the CON group, the three doses of CSB significantly improved egg production after the S. Enteritidis challenge (P_ANOVA < 0.05). S. Enteritidis challenge increased plasma DAO activity, but CSB supplementation reduced plasma DAO activity (P_linear < 0.05). The S. Enteritidis challenge disrupted intestinal villi morphology; compared to the CON group, the three dosages of CSB resulted in an increase in villus height (VH) and the ratio of villus height to crypt depth (V/C) in the duodenum, jejunum, and ileum of infected laying hens (P_linear < 0.05), with a significant increase in jejunal villus height (P_ANOVA < 0.05). A decrease in ileal crypt depth was also observed (P_linear < 0.05). CSB2 and CSB3 markedly increased the content of butyric acid in the cecum (P_ANOVA < 0.05). Additionally, in contrast to those in the CON group, the propionic acid content in the CSB supplementation group increased (P_linear < 0.05). Compared with those in the CON group, mRNA relative expression of the IL-6 and IL-1β in jejunum (P_linear < 0.05) and mRNA relative expression of the IL-1β in ileum (P_ANOVA < 0.05) were significantly lower, and mRNA relative expression of the IL-10 in ileum (P_linear < 0.05) were significantly higher in the CSB group. In addition, in contrast to the CON group, the CSB supplementation group significantly upregulated mRNA relative expression of the ZO-1 and CLDN1 (P_ANOVA < 0.05). Additionally, CSB supplementation reduced the number of Salmonella and increased the number of Lactobacilli in the cecum (P_linear < 0.05) and tended to increase the total bacteria count (P_linear = 0.069) and reduce the E. coli count (P_linear = 0.081). In conclusion, long-term dietary supplementation with coated sodium butyrate can alleviate intestinal injury and the colonization of cecum Salmonella in laying hens infected with S. Enteritidis. Full article

Studies have shown that the production of reactive oxygen species (ROS) is triggered by bactericidal antibiotics, which contributes significantly to the killing of bacterial cells and increasing mutations in surviving cells. In this study, we hypothesized that exposure of Salmonella to sublethal concentrations of hypochlorite (NaOCl), a commonly used sanitizer in household and food industries increases mutation rates, leading to the development of antibiotic resistance. We found that a sublethal concentration (20 ppm) of NaOCl increased the mutation rates of S. typhimurium 14028s significantly (p < 0.05), which was prevented by the ROS scavenger thiourea, supporting that the increased mutation was due to NaOCl-triggered ROS production. We further found that the exposure of S. typhimurium 14028s to the same sublethal concentration of NaOCl increases resistance to kanamycin among the 3 antibiotics evaluated. The results of this study suggest that when NaOCl applied as a sanitizer fails to kill Salmonella due to diluted local concentrations or presence of organic materials, it can cause an adverse outcome of developing antibiotic resistance of the pathogen. Full article

Tetracyclines have a high resistance percentage in Salmonella spp. of both human and animal origin. Essential oils, such as cinnamon (Cinnamomum zeylanicum), clove (Eugenia caryophyllata), oregano (Origanum vulgare), and red thyme (Thymus zygis), have shown bactericidal activity against this bacterium. However, in many cases, the minimum inhibitory concentration (MIC) exceeds the cytotoxicity limits. The objective of this study was to assess the in vitro efficacy of combining oxytetracycline with essential these oils against field multidrug-resistant (MDR) Salmonella enterica strains. The MIC of each product was determined using the broth microdilution method. The interaction was evaluated using the checkerboard method, by means of the fractional inhibitory concentration index (FIC_index) determination. The results showed a positive interaction (synergy and additivity) between oxytetracycline and the four oils tested, resulting in a reduction in both products’ MICs by 2 to 4 times their initial value, in the case of oils, and by 2 to 1024 times in the case of the antibiotic. The combination of oxytetracycline and cinnamon achieved the best results (FIC_index 0.5), with a decrease in the antibiotic effective concentration to below the sensitivity threshold (MIC of the combined oxytetracycline 0.5 µg/mL). There was no antagonistic effect in any case, although differences in response were observed depending on the bacterial strain. The results of this study suggest that combining oxytetracycline with cinnamon oil could be an effective alternative for controlling tetracycline-resistant strains of Salmonella. However, its individual use should be further evaluated through in vitro susceptibility tests. Full article

Salmonella is a common foodborne pathogen that can cause food poisoning, posing a serious threat to human health. Therefore, quickly, sensitively, and accurately detecting Salmonella is crucial to ensuring food safety. For the Salmonella hilA gene, we designed Recombinase-aided amplification (RAA) primers and dsDNA-specific nuclease (DNase) probes. The ideal primer and probe combination was found when conditions were optimized. Under UV light, a visual Salmonella detection technique (RAA-dsDNase) was developed. Additionally, the RAA-dsDNase was modified to further reduce pollution hazards and simplify operations. One-pot RAA-dsDNase-UV or one-pot RAA-dsDNase-LFD was developed as a Salmonella detection method, using UV or a lateral flow dipstick (LFD) for result observation. Among them, one-pot RAA-dsDNase and one-pot RAA-dsDNase-LFD had detection times of 50 min and 60 min, respectively, for detecting Salmonella genomic DNA. One-pot RAA-dsDNase-UV had a detection limit of 10¹ copies/μL and 10¹ CFU/mL, while one-pot RAA-dsDNase-LFD had a sensitivity of 10² copies/μL and 10² CFU/mL. One-pot RAA-dsDNase-UV and one-pot RAA-dsDNase-LFD assays may identify 17 specific Salmonella serovars witho ut causing a cross-reaction with the remaining 8 bacteria, which include E. coli. Furthermore, Salmonella in tissue and milk samples has been reliably detected using both approaches. Overall, the detection method developed in this study can quickly, sensitively, and accurately detect Salmonella, and it is expected to become an important detection tool for the prevention and control of Salmonella in the future. Full article

Higher plants produce secondary metabolites expressing antimicrobial effects as a defense mechanism against opportunistic microorganisms living in close proximity with the plant. Fermentation leads to bioconversion of plant substrates to these bioactive compounds and their subsequent release via breakdown of plant cell walls. Fermented feed products have recently started to become implemented in the pig industry to reduce overall disease pressure and have been found to reduce events such as post-weaning diarrhea. In this study, we investigate the antimicrobial potential of fermented soybean- and rapeseed-based pig feed supplements with and without added seaweed. The antimicrobial effect was tested in a plate well diffusion assay against a range of known human and livestock pathogenic bacteria. Further, we investigate the metabolite profiles based on liquid-chromatography mass-spectrometry (LC-MS) analysis of the fermented products in comparison to their unfermented constituents. We observed a pronounced release of potential antimicrobial secondary metabolites such as benzoic acids when the plant material was fermented, and a significantly increased antimicrobial effect compared to the unfermented controls against several pathogenic bacteria, especially Salmonella enterica Typhimurium, Listeria monocytogenes, Yersinia enterocolitica, and a strain of atopic dermatitis causing Staphylococcus aureus CC1. In conclusion, fermentation significantly enhances the antimicrobial properties of rapeseed, soybean, and seaweed, offering a promising alternative to zinc oxide for controlling pathogens in piglet feed. This effect is attributed to the release of bioactive metabolites effective against pig production-relevant bacteria. Full article

Traditional and regional foods have been increasing in popularity among consumers in Poland for many years. The observed trend of searching for natural and authentic taste encourages many producers to craft products from raw milk, including Koryciński cheeses. The aim of this study was to assess the microbiological hazards resulting from the presence of pathogenic bacteria in Koryciński cheeses available in retail trade. The tests were carried out using accredited methods, including the detection of the presence of Salmonella spp., the enumeration of Listeria monocytogenes, the enumeration of coagulase-positive staphylococci, and the detection of staphylococcal enterotoxins in food when the number of coagulase-positive staphylococci in the sample exceeded the limit of 10⁵ cfu/g. The research material consisted of 45 Koryciński cheeses. The tests conducted revealed that Salmonella spp. was not detected in any of the examined cheeses. However, coagulase-positive staphylococci were present in 68.9% of the samples. In as many as 15 tested cheeses, the level of S. aureus contamination was above 10⁵ cfu/g; therefore, these samples were tested for the presence of staphylococcal enterotoxins. The presence of staphylococcal enterotoxins was found in one Koryciński cheese. In four cheeses, the number of L. monocytogenes exceeded the level of 10² cfu/g, the limit specified in Regulation 2073/2005 on microbiological criteria for foodstuffs. The obtained research results confirm the validity of monitoring the microbiological quality of Koryciński cheeses and the need to increase awareness of ensuring proper hygienic conditions of production, including the increased risk associated with unpasteurized milk products. Full article