Development of Active Packaging Based on Agar-Agar Incorporated with Bacteriocin of Lactobacillus sakei

In the search for new biodegradable materials and greater microbiological safety and stability of perishable food products, this study aimed to develop a bioplastic antibacterial film incorporating bacteriocin for application in commercial curd cheese and monitoring of microbiological stability. Films with good handling characteristics as well as physical, barrier, and mechanical properties were obtained. Regarding the antibacterial activity, the microbial reduction was demonstrated in a food matrix, obtaining a reduction of 3 logarithmic cycles for the group of coagulase positive staphylococci and from 1100 to <3.00 MPN/g in the analysis of thermotolerant coliforms. Therefore, the film presented food barrier characteristics with the external environment and adequate migration of the antibacterial compound to the product, contributing to the reduction of contamination of a food with high initial microbial load.

Occurrence of selected pathogenic microorganisms in raw and processed eggs of snails of the Cornu genus

Introduction This study investigated the eggs of Polish-bred edible snails of the Cornu genus as a food and aimed to determine the presence of microorganisms in them of the Salmonella and Listeria genera and ascertain the number of coagulase-positive staphylococci. Material and Methods Raw material, semi-finished products, and the final product were collected during the production cycle. Testing for the presence of Salmonella spp. and Listeria spp. and measuring of the pathogenic staphylococci contamination level were carried out in accordance with ISO standards. Commercial biochemical tests were used for species identification of bacteria of the Enterobacteriaceae family and Staphylococcus genus. An API kit and a PCR protocol were utilised for species confirmation of the microorganisms of the Listeria genus. Results Neither Salmonella nor coagulase-positive staphylococci were found in any of the studied material. Bacteria of the Listeria genus were found in samples taken at every stage of production; however L. monocytogenes was confirmed in samples of the final product. Conclusion The absence of Salmonella spp. and Staphylococcus aureus in samples of the final product indicates that the required hygiene standard was maintained in the production process of edible snail eggs. Nevertheless, the presence of L. monocytogenes in eggs of common garden snails may pose a potential risk to consumer health.

Multidrug Resistant Coagulase-Positive Staphylococcus aureus and Their Enterotoxins Detection in Traditional Cheeses Marketed in Banat Region, Romania

The main objectives of the present study were to determine the occurrence of coagulase positive staphylococci (CPS) and to assess the presence and antimicrobial susceptibility profile of Staphylococcus aureus isolates in different raw milk origin (cow and sheep) traditional cheeses marketed in Banat region, Romania. Additionally, the presence of mecA gene in S. aureus isolates and the staphylococcal enterotoxins (SEs) in cheese samples were evaluated. A total of 81.6% (138/169) of the screened samples were positive for CPS. Furthermore, 35.5% (49/138) of the investigated CPS positive cheese samples were contaminated with S. aureus, with an isolation frequency of 46.6% (14/30) in caș, 33.3% (32/96) in telemea, 25% (2/8) in burduf, and 25% (1/4) in urdă assortments, respectively. From the total number of S. aureus isolates, 6.1% (3/49) harbored the mecA gene. Detectable levels of SEs were identified in 4.3% (4/94) of cheese samples with a CPS contamination level higher than 105 log CFU g−1. The expressed antimicrobial susceptibility profile of the tested cheese-origin S. aureus isolates, with the automated Vitek 2 equipment, showed resistance towards amikacin (90.1%, 10 out from 11 tested), enrofloxacin (86.2%, 25/29), ceftiofur (72.7%, 8/11), neomycin (63.6%, 7/11), benzylpenicillin (53.1%, 26/49), kanamycin (41.4%, 12/29), rifampicin (39.5%, 15/38), tetracycline (38.8%, 19/49), tilmicosin (36.4%, 4/11), clindamycin (30.6%, 15/49), ciprofloxacin (30%, 6/20), erythromycin (22.4%, 11/49), tylosin (18.2%, 2/11), oxacillin (16.3%, 8/49), linezolid (15%, 3/20), teicoplanin (15%, 3/20), fusidic acid (13.1%), imipenem (10.5%, 4/38), vancomycin (7.9%, 3/38), ampicillin (5.5%, 1/18), mupirocin (5.5%, 1/18), fosfomycin (5%, 1/20), and gentamicin (4.1%, 2/49). Twenty-four (49%) S. aureus isolates exhibited multidrug resistance. The investigation highlighted a common occurrence of multidrug-resistant S. aureus strains in the monitored cheese assortments, which can constitute a potential risk for consumers’ health.

Hygienic-sanitary quality of ready-to-eat salmon sashimi (Salmo Salar)

Fifty sashimi samples from 5 restaurants were characterized for enumeration of Aerobic Psychrotrophic Heterotrophic Bacteria (APHB) and Aerobic Mesophilic Heterotrophic Bacteria (AMHB), Enterobacteriaceae, coliforms at 45ºC (thermotolerant coliforms), coagulase-positive Staphylococci, presence of Vibrio parahaemolyticus and Salmonella sp., and determination of hydrogen potential (pH) and total volatile basic nitrogen (TVB-N). The bacterial isolates were evaluated for their resistance profile to the antimicrobial agents Penicillin, Ampicillin, Cefoxitin, Cefotaxime, Amikacin, Gentamicin, Tetracycline, and Trimethropim-sulfamethoxazole. The results showed that APHB, AMHB and coagulase-positive Staphylococci counts and the determination of pH and TVB-N were in accordance with national and international standards adopted as safe limits for consumption. In contrast, the Enterobacteriaceae and thermotolerant coliforms counts and presence of Salmonella sp. and V. parahaemolyticus were in disagreement with those standards, raising concern about the hygienic-sanitary quality of sashimi. The Staphylococcus aureus and V. parahaemolyticus isolates showed resistance to Penicillin, Ampicillin, Cefoxitin, Cefotaxime, Tetracycline, Gentamicin, and Amikacin, while the Salmonella sp. isolate showed no resistance to all the antimicrobial agents studied. The results showed that 48% of the samples were fit for consumption while 52% had unsatisfactory hygienic-sanitary quality for the parameters evaluated.

Ready-to-eat foods: A potential vehicle for spread of coagulase-positive staphylococci and antibiotic-resistant Staphylococcus aureus in Buea municipality, South West Cameroon

Background The consumption of ready-to-eat (RTE) foods contaminated with coagulase-positive staphylococci (CoPS) and especially Staphylococcus aureus puts consumers at potential risk of foodborne disease or colonization and subsequent infection. This cross-sectional study determined the levels of CoPS and the presence of S. aureus in RTE foods sold in Buea municipality. Method A total of 420 RTE food samples comprising 70 each of cake, bread, fruit salad, meat-hot-pot, suya and boiled rice were randomly purchased from February to August 2020. The CoPS counts were determined by culturing on Baird-Parker agar and S. aureus identified by amplification of the nuc gene using polymerase chain reaction. All S. aureus isolates were screened for the presence of classical staphylococcal enterotoxin genes and each isolate challenged with 11 antibiotics to determine their antibiotic susceptibility profiles. Oxacillin-resistant S. aureus were analyzed for the presence of mecA gene. Result Overall, 161 (38.3%) samples had detectable levels of coagulase-positive staphylococci ranging from 2.0-5.81 log10CFU/g. Based on CoPS levels, 37 (8.81%) of the 420 RTE food samples, only fruit salad and meat-hot-pot, had unsatisfactory microbiological quality. A total of 72 S. aureus isolates, comprising 52.78% from fruit salad, 16.67% from meat-hot-pot, 12.5% from boiled rice, 9.72% from suya, 5.56% from bread and 4.17% from cake were recovered. None of the S. aureus isolates possessed any of the classical enterotoxin genes. All the isolates were sensitive to vancomycin and ofloxacin while 68 (94.44%) and 66 (91.67%) were sensitive to oxacillin and ciprofloxacin, respectively. Resistance to penicillin (93.06%) was highest followed by amoxicillin (91.67%) and erythromycin (79.17%). Four isolates were identified as methicillin-resistant S. aureus all of which carried the mecA gene. A total of 24 antibiotypes were identified. Conclusion Our findings showed that RTE foods sold in the Buea municipality are likely vehicles for transmission of CoPS and antibiotic-resistant S. aureus.

Microbiological quality assessment of five common foods sold at different points of sale in Burkina-Faso

The aim of the present study was to assess the microbial quality of five different types of food such as bread, pasta, rice with sauce, beans and milk sold in five localities of Burkina Faso. One hundred and one (101) samples were collected and microbial quality were assessed by evaluating the food hygiene indicators such as total aerobic mesophilic flora, total coliforms, thermotolerant coliforms, yeast and mould. Food safety indicators such as Escherichia coli , Salmonella , coagulase-positive staphylococci, Clostridium perfringens and Bacillus cereus were checked too. All samples were analyzed under ISO methods.