Abstract Salmonella Enteritidis is the major cause of foodborne salmonellosis affecting human health. The light emitting diodes (LEDs) is a novel approach to inactivate of the foodborne pathogens. The aim of this study was to determine the antibacterial effect of 405 nm LEDs illumination on S. Enteritidis and S. Enteritidis PT4. The irradiance of the 405 nm LEDs was 27.7 mW/cm2. Bacterial cultures suspended in tryptic soy broth were illuminated by 10-watt LEDs at a distance of 4.5 cm for 24 hours at 4 °C, 25 °C and 37 °C. Approximately 7-log reduction in colony forming unit (CFU) counts of both S. Enteritidis and S. Enteritidis PT4 at each temperature were observed following exposure after 7.5 hours to the LEDs, concluding that temperature did not affect the inactivation of the bacteria. The decimal reduction times (D-values) for the serotypes ranged from 55.78 to 67.88 min at 4, 25 and 37 °C after 405 nm LEDs illumination. No significant difference in D-values was observed among both the serotypes and temperatures, except for S. Enteritidis which had lower D-value at 4 °C. The LEDs technology has shown antibacterial efficacy and can be implemented in the food processing for reducing S. Enteritidis.

Abstract Salmonella Typhimurium is one of the most common foodborne pathogens isolated from poultry meat. The goal of this study was to investigate S. Typhimurium survival in broiler carcasses exposed to ozone, lactic acid, sodium hypochlorite and levulinic acid. S. Typhimurium was inoculated into broiler carcasses, which were divided into eight treatment groups, including a positive and negative control group. After standardized bacterial culture methods, microbiological analysis revealed a statistically significant relationship between the number of bacteria detected and the concentration and application time in all the treatment groups (p < 0.05). As compared with the control group, all the treatments were effective in terms of inactivation of S. Typhimurium. There was a significant decrease in the 1.5 ppm ozone treatment group (5 min and 15 min) as compared with that in the other chemical decontaminant groups (p < 0.05). However, there was no significant difference in reduction of S. Typhimurium among the other treatment groups, irrespective of the treatment time (p > 0.05). Among the decontaminants, the most effective chemical solution was 3% LEV. The ozone treatment caused a lower logarithmic decrease in S. Typhimurium numbers at all treatment times as compared with that in the other treatment groups.

Abstract Staphylococcus aureus is the leading cause of intoxications in humans. Also, methicillin-resistant S. aureus (MRSA) is an emerging problem in food-producing animals. The presence of MRSA in milk may create a risk to public health. The aim of this study was to evaluate the presence of MRSA in bulk tank milk samples. One hundred and twenty bulk tank milk samples were analyzed using the convenient sampling method. The isolates were confirmed by real-time polymerase chain reaction (RT-PCR) targeting nuc and mecA gene in S. aureus. Antibiotic resistance profiles of the isolates were tested by disc agar diffusion method. In the current study, S. aureus was detected in 44 (36.66%) of the samples. The presence of the mecA gene was found to be positive in 40 (75.4%) of the 53 S. aureus isolates. As a result of the study, a high incidence of MRSA was detected in bulk tank milk samples. Antibiotic-resistant bacteria are at risk of being transferred to humans via milk. For safe and healthy milk consumption, uncontrolled use of antibiotics in dairy cows should be avoided.