Antimicrobial and antibiofilm effects of selected food preservatives against Salmonella spp. isolated from chicken samples.

Salmonella spp. are widespread foodborne pathogens that contaminate egg and poultry meats. Attachment, colonization, as well as biofilm formation capacity of Salmonella spp. on food and contact surfaces of food may cause continuous contamination. Biofilm may play a crucial role in the survival of salmonellae under unfavorable environmental conditions, such as in animal slaughterhouses and processing plants. This could serve as a reservoir compromising food safety and human health. Addition of antimicrobial preservatives extends shelf lives of food products, but even when products are supplemented with adequate amounts of preservatives, it is not always possible to inhibit the microorganisms in a biofilm community. In this study, our aims were i) to determine the minimum inhibitory concentrations (MIC) and minimum biofilm inhibitory concentrations (MBIC) of selected preservatives against planktonic and biofilm forms of Salmonella spp. isolated from chicken samples and Salmonella Typhimurium SL1344 standard strain, ii) to show the differences in the susceptibility patterns of same strains versus the planktonic and biofilm forms to the same preservative agent, and iii) to determine and compare antimicrobial and antibiofilm effects of selected food preservatives against Salmonella spp. For this purpose, Salmonella Typhimurium SL1344 standard strain and 4 Salmonella spp. strains isolated from chicken samples were used. Investigation of antimicrobial and antibiofilm effects of selected food preservatives against Salmonella spp. was done according to Clinical and Laboratory Standards Institute M100-S18 guidelines and BioTimer assay, respectively. As preservative agents, pure ciprofloxacin, sodium nitrite, potassium sorbate, sodium benzoate, methyl paraben, and propyl paraben were selected. As a result, it was determined that MBIC values are greater than the MIC values of the preservatives. This result verified the resistance seen in a biofilm community to food preservatives and highlighted this subject, not to be ignored in food applications.

Screening of quinolone antibiotic residues in chicken meat and beef sold in the markets of Ankara, Turkey.

This study aimed to find the effects of quinolone antibiotics in chicken and beef used in Ankara, Turkey. Total number of 127 chicken and 104 beef meat samples were collected randomly from local markets for analysis. Extraction and determination of quinolones were made by ELISA procedure. One hundred eighteen of 231 (51.1%) examined chicken meat and beef samples were found to contain quinolone antibiotic residue. Among the chicken meat and beef samples, 58 (45.7%) of chicken meat samples and 60 (57.7%) of beef meat samples were positive for quinolones, respectively. The mean levels (±SE) of quinolones were found to be 30.81 ± 0.45 µg/kg and 6.64 ± 1.11 µg/kg in chicken and beef samples, respectively. This study indicated that some chicken and beef meat sold in Ankara contains residues of quinolone antibiotics.

Sulfite leads to neuron loss in the hippocampus of both normal and SOX-deficient rats.

Sulfites are compounds commonly used as preservatives in foods, beverages and pharmaceuticals. Sulfite is also endogenously generated during the metabolism of sulfur-containing amino acids and drugs. It has been shown that sulfite is a highly toxic molecule. Many studies have examined the effects of sulfite toxicity, but the effect of ingested sulfite on the number of neurons in the hippocampus has not yet been reported. The present study was undertaken to investigate the effect of ingested sulfite on pyramidal neurons by counting cells in CA1 and CA3-2 subdivisions of the rat hippocampus. For this purpose, rats were assigned to one of four groups (6 rats per group): control (C), sulfite (S), deficient (D) and deficient+sulfite (DS). Sulfite oxidase deficiency was established by feeding rats a low molybdenum diet and adding 200ppm tungsten (W) to their drinking water. Sulfite (70mg/kg) was also administered to the animals via their drinking water. At the end of the experimental period, the rats were sacrificed by exsanguination under anesthesia, and their brains and livers quickly removed. The livers were used for a SOX activity assay, and the brains were used for neuronal counts in a known fraction of the CA1 and CA3-2 subdivisions of the left hippocampus using the optical fractionator method, which is a stereological method. The results showed that sulfite treatment caused a significant decrease in the total number of pyramidal neurons in three subdivisions of the hippocampus (CA1 and CA3-2) in the S, D and DS groups compared with the control group. It is concluded that exogenous administration of sulfite causes loss of pyramidal neurons in CA1 and CA3-2 subdivisions in both normal and SOX deficient rat hippocampus. This finding provides supporting evidence that sulfite is a neurotoxic molecule.