No abstract

This study aimed to investigate the prevalence of foodborne pathogenic bacteria in bovine milk, their antibiogram phenotype, and the carriage of antibiotic resistance genes. Raw bovine milk samples (n = 100) were randomly collected from different suppliers in the northwest of Iran. Antibiotic-resistant patterns and the presence of antibiotic resistance genes were evaluated in the isolates. Escherichia coli, Listeria monocytogenes, Staphylococcus aureus, and Salmonella spp. were isolated from 78%, 47%, 25%, and 21% of samples, respectively. All isolates showed high rates of resistance to amoxicillin, penicillin, and cefalexin. The blaTEM and blaSHV genes were detected in 50.0% and 6.4% of E. coli isolates, respectively. Also, 28.5% and 19.0% of Salmonella isolates were positive for blaTEM and blaSHV. The frequency of mecA and blaZ in S. aureus isolates was 20.0% and 12.0%, respectively. The high prevalence of bovine milk contamination with antimicrobial-resistant species in this study necessitates precise control on antibiotic prescription in veterinary medicine.

No abstract

Due to the enhancement of antimicrobial activity, nanoencapsulation of plant EOs and extracts may increase their commercial application not only in food area but also in the pharmaceutics, cosmetics and health products.

No abstract

The essential oil (EO) of Zataria multiflora Bioss. was successfully encapsulated into nanoliposomes in this study. The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of EO loaded nanoliposomes and free EO were studied at 25 and 35C against Escherichia coli O157:H7. Effect of sub-inhibitory concentrations (subMIC) of EO was also evaluated before and after encapsulation against the growth of bacteria over 24 h. MIC and MBC levels for EO loaded nanoliposomes decreased in comparison with free EO. Antibacterial effect of free and nanoliposomal EO also followed a dose-dependent manner. By sub-MIC concentration of nanoliposomal EO, bacterial count was decreased more than free EO especially at 8, 12 and 24 h. Furthermore, sub-MIC concentration of liposomal EO showed a better inhibitory effect at 35C than 25C. The findings of this research showed that novel carries like nanoliposomes can increase the antibacterial effect of EOs like Z. multiflora EO. PRACTICAL APPLICATIONSThis study raises important implications for the potential use of nanoliposome as a novel carrier for Zataria multiflora Boiss. essential oil. The increased antimicrobial activity of Zataria multiflora Boiss. essential oil against Escherichia coli O157:H7 after the encapsulation in nanoliposomes can promote the use of similar encapsulated natural compounds in nanoliposomes as potent preservative agents, not only in the food industry but also in medical and cosmetics preparations.

No abstract

Listeria monocytogenes is a foodborne pathogen that is widespread in the environment. There are several reports on the isolation of L. monocytogenes from many types of cheeses. The aim of this study was to evaluate the antibacterial effect of Mentha spicata essential oil on L. monocytogenes in traditional Lighvan cheese. L. monocytogenes was added to the raw ewe's milk and M. spicata essential oil was subsequently mixed with the milk at concentrations of 0, 2 and 2.5%. After producing the cheese, sampling performed until 60 days. Results of this study showed that M. spicata essential oil at all concentrations was effective against L. monocytogenes in comparison with the control group (P < 0.001). There was no significant difference between 2 and 2.5%. Effect of the M. spicata essential oil on L. monocytogenes at 14C was greater than 4C. Also, with increasing salt water concentration, the anti-Listerial effect of the M. spicata essential oil increased. PRACTICAL APPLICATIONSThese findings may be of significant importance with regard to food safety because application of M. spicata essential oils for control of L. monocytogenes in unpasteurized and traditional cheeses tested and achieved best results. Also, environmental conditions (NaCl and temperature) increased antibacterial effect of M. spicata in cheese.