Prevalence and Antibiotic Resistance of Bacillus sp. Isolated from Raw Milk.

Milk, due to its diversity in terms of its nutritional content, is an important element of the human diet, as well as a good medium for the development of bacteria. The genus Bacillus contains ubiquitous aerobic, rod-shaped, endospore-producing gram-positive bacteria. Representatives of the Bacillus cereus group and the Bacillus subtilis group contribute to shortening the shelf life of milk and dairy products by degrading milk components and its additives. They also produce a number of heat-stable toxins and can cause a number of ailments, mainly in the digestive system. The aim of this research was to identify Bacillus sp. strains isolated from raw milk and to determine their antibiotic resistance. Strains isolated from raw milk samples (n = 45) were identified by MALDI-TOF MS. Ninety strains of Bacillus sp. were identified, for which the antibiotic resistance phenotype was determined. A total of 90 strains of Bacillus were classified in five groups (the Bacillus cereus group (n = 35), B. licheniformis (n = 7), the B. subtilis group (n = 29), B. pumilus (n = 16), and Bacillus sp. (n = 3). All isolates were susceptible to chloramphenicol and meropenem. The antibiotic resistance profiles of the tested groups of Bacillus spp. differed from each other, which is of particular concern in relation to multidrug-resistant representatives of the B. cereus group resistant to cefotaxime (94.29%), ampicillin (88.57%), rifampicin (80%), and norfloxacin (65.71%). Our study provides data on the prevalence and antibiotic sensitivity of Bacillus sp. In raw milk, suggesting a potential risk to health and the dairy industry.

Antioxidant and Antimicrobial Properties of Selected Fruit Juices.

Fruit and fruit juices are a valuable source of bioactive compounds, which can protect our organisms from oxidative stress. The phenolic compounds and other phytochemicals may affect the antimicrobial properties of juices. The aim of this study has been to evaluate antioxidant and antimicrobial properties of selected berry juices and vitamin C-rich fruit juices. The research material was composed of seven juices, including three from berries (elderberry chokeberry, cranberry), three from vitamin C-rich fruit (sea buckthorn, wild rose, Japanese quince) and one exotic juice from noni fruit. Antioxidant capacity, total polyphenol, total flavonoid and total anthocyanin content were determined. Furthermore, the antimicrobial activity and the minimal inhibitory concentration (MIC) as well as the minimal bactericidal concentration (MBC) were evaluated. The research showed that fruit juices from wild rose, chokeberry and Japanese quince had the highest antioxidant capacity. These juices were characterised by the rich content of polyphenols. Elderberry and chokeberry juices had the highest total anthocyanins. The juices differed in the content of bioactive compounds and specific bactericidal properties against Gram-positive or Gram-negative bacteria. Fruit juices from cranberry, Japanese quince and sea buckthorn had the highest antimicrobial activity. Wild rose, chokeberry and elderberry juices, despite their high antioxidant properties, showed antimicrobial activity only against Gram-positive strains, except Enterococcus faecalis and Clostridium perfringens. Significant differences in the content of bioactive compounds in fruit juices affect the antimicrobial properties juices.

The Profile of Polyphenolic Compounds, Contents of Total Phenolics and Flavonoids, and Antioxidant and Antimicrobial Properties of Bee Products.

This study aimed to characterize bee products (bee bread, bee pollen, beeswax, and multiflorous honey) with the profile of phenolic compounds, total phenolic (TPC) and flavonoid (TFC) contents, and antioxidant and microbiological properties. The TP and TF contents could be ordered as follows: bee pollen > bee bread > beeswax > honey. The UPLC-PDA-MS/MS analysis allowed identifying 20 polyphenols. Sinapic acid dominated in bee pollen, gallic acid in the bee bread and honey, while pinobanksin was the major compound of beeswax. The data showed that bee pollen and bee bread had a stronger antioxidant potential than honey and beeswax. Moreover, the antibacterial activity of the bee products was studied using 14 bacterial strains. Bee bread's and bee pollen's antimicrobial activity was higher towards Gram-negative strains. In comparison, honey was more potent in inhibiting Gram-positive bacteria. Our study indicates that bee products may represent valuable sources of bioactive compounds offering functional properties.

Antioxidant properties and antimicrobial activity of manuka honey versus Polish honeys.

Originating from New Zealand manuka honey distinguishes itself from other honeys. The purpose of this study was to compare the antioxidant and antimicrobial properties of manuka honey and selected Polish honeys. Antioxidant capacity, total polyphenol and total flavonoid content were determined. Furthermore, the antimicrobial activity and the Minimum Inhibitory Concentration (MIC) were evaluated. Obtained results demonstrated that manuka honeys possessed relatively high antioxidant capacity compared to the other, Polish honeys. It was only honeydew honey that achieved comparable antioxidant properties to manuka honeys. The findings were supported by the results of microbial assays. Manuka MGO-250 and MGO-400, alongside honeydew honey, showed a stronger antimicrobial effect against Gram(+) than against Gram(-) bacteria. Moreover, the MIC-values, expressed as an inhibin number, proved the high antibiotic activity of manuka honey against the strains of Staphylococcus aureus and Enterococcus faecalis. Research concerning the influence of manuka honey on human health should be continued.

Microbiological contamination of dried and lyophilized garlic as a potential source of food spoilage.

Garlic is valued more for its flavoring and used in a wide variety of foods. In food technology, fresh garlic is not used, but instead its processed forms, most often dried and lyophilized, are utilized. The quality and safety of the final product largely depends on their microbiological quality. This research has provided information about effect of garlic fixation methods and provided information about effect of microbiological contamination of garlic used as a spice for quality of garlic mayonnaise sauce. The authors decided to undertake studies following a report from one of the manufacturers of garlic sauces on product defects which originated in dried garlic used in the production process. Samples of garlic (n = 26) were examinated using standard cultural methods (counts of fungi, lactic acid bacteria-LAB, spore-producing Bacillus sp. and the presence of anaerobic saccharolytic and proteolytic clostridia), automated system TEMPO (total viable count, Enterobacteriaceae), immunoenzymatic method using VIDAS tests (occurrence of Salmonella sp. and Listeria monocytogenes). The number of total viable count was ranged from 3.51 to 6.85 log CFU/g. Enterobacteriaceae were detected only in one sample. Comparably low values were recorded for fungi (1.30 to 3.47 log CFU/g). The number of LAB was ranged from 2.34 to 5.49 log CFU/g. Clostridium sp. were detected in 22 samples. Salmonella sp. and Listeria monocytogenes were not detected. It was found that garlic, regardless of th preservation procedure, might be a source of contamination of garlic mayonnaise sauce especially with lactic acid bacteria and Clostridium sp. spores.

Vidas UP-enzyme-linked fluorescent immunoassay based on recombinant phage protein and fluorescence in situ hybridization as alternative methods for detection of Salmonella enterica serovars in meat.

Several methods for the rapid and specific detection of Salmonella spp. in meat have been described. This study was conducted to evaluate the capability of the VIDAS(®) UP (SPT [Salmonella Phage Technology]), an enzyme-linked fluorescent immunoassay method, and fluorescence in situ hybridization (FISH) to complement the International Organization for Standardization Method 6579 (ISO) in detecting Salmonella spp. from beef, pork, and poultry meat samples. The meat was inoculated with a mixture of Salmonella spp. on three levels of contamination. It was also checked that the tests did not produce cross-reactions with other Enterobacteriaceae rods. On the basis of the results, the relative specificity, relative accordance, and relative sensitivity of the method were determined. In meat samples, Vidas UP and FISH detection results were in substantial agreement with ISO, with relative specificity, accordance, and sensitivity rates of 90%, 96.3%, and 100%, respectively, for Vidas UP and 100%, 100%, and 99.4%, respectively, for FISH. This is the first report on the evaluation of both Vidas UP and FISH compared to ISO for the rapid detection of Salmonella enterica serovars in meat.

Application of synbiotics in fermented sausage production.

The aim of the study was to produce of no-maturating fermented sausage with addition of inulin and probiotic strains. The study included production of sausages with addition of probiotics strains, growth promoting and texture inulin, determination of growth of probiotic bacteria in a final product during its storage period, determination of influence of synbiotic on undesired microflora and organoleptic quality of product. Microbial quality of sausages has been satisfactory. The number of undesired rods didn't exceed admissible standards. Amount of probiotic bacteria, which had been added to 3 types of products, achieved the level up to 1.010(6) cfu/g in all samples of sausages stored at different temperature. No significant differences in number of probiotic bacteria have been noted as a result of prebiotic addition. In organoleptic evaluation a beneficial effect of synbiotics on sensory properties, especially their structure and consistency has been observed.