The contamination of fresh produce with antibiotic-resistant bacteria is of particular concern as they are often eaten raw and can be a source for foodborne diseases. Tetracyclines have been largely used in humans, animals and plants which might have accelerated microbial resistance to them. Enterococci and Escherichia coli can be used as indicators to monitor contamination of the fresh produce with tetracycline-resistant bacteria. The investigation related to this issue is very scarce in Oman. This study aimed at identifying tetracycline-resistant enterococci and E. coli in fresh produce at the market place. Thirty-one enterococci and ten E. coli were isolated from local (Oman) and imported fruits and vegetables (N= 105). Using the standard Kirby-Bauer disc diffusion method, resistance to tetracycline was found in 6 (19 %) enterococci, isolated from cucumber, lettuce and radish, and 5 (50 %) E. coli, obtained from cabbage, lettuce and radish. Genetic analysis revealed the presence of tetracycline resistance genes, tet(A) and tet(K), in E. coli and tet(K), tet(L) and tet(M) in enterococci, including Enterococcus sulfureus, Enterococcus mundtii, Enterococcus casseli avus and Enterococcus faecalis. The integron integrase IntI 1 gene, which is known to facilitate the dissemination of antibiotic resistance genes among bacteria, was detected in 2 isolates of E. coli. These results demonstrated the capability of fresh produce to act as a potential source for disseminating tetracycline or possibly other antibiotic-resistant bacteria through the food chain. Thus, control strategies are needed to reduce exposure of the public to such microorganisms.

This study aimed to elucidate the effect of ambient storage (23±2°C, 68% RH) on the bacterial load and diversity, biogenic amines and lipids oxidation in traditional dried anchovy (E. punctifer) in order to evaluate its safety, quality and stability during 12 weeks of storage. Total aerobic bacteria (TAB), Staphylococcus aureus, Enterobacteriaceae (ENT), histidine decarboxylating bacteria (HDB), lysine decarboxylating bacteria (LDB) and ornithine decarboxylating bacteria (ODB) were enumerated and identified by conventional, VITEK 2 compact and sequencing of 16S rRNA gene methods. Histamine, cadaverine and putrescine contents were determined by high performance liquid chromatography. Lipid oxidation was evaluated by peroxide value (PV). Total aerobic bacteria, S. aureus, ENT, HDB, LDB and ODB initial counts of log10 4.9 ± 0.85, 3.7 ± 0.57, 4.2 ± 0.05, 3.7 ± 0.72, 3.9 ± 0.40 and 4.1 ± 0.24 CFU/g respectively did not significantly change (p > 0.05) during 12 weeks of storage. A high bacterial diversity of 27 species belonging to 20 genera was found, with the dominance of S. aureus, Acinetobacter lwoffii and S. warneri and the first incidence of Psychrobacter celer, Desemzia incerta, Granulicatella elegans and Bhargavaea indica in dried fish.  Initial histamine, cadaverine and putrescine contents and PV of 5.2 ± 4.3, 8.5 ± 1.9 and 5.8 ± 0.6 mg/100g and 0.19 ± 0.02 meq/kg respectively did not significantly change (p > 0.05) during 12 weeks of storage. This study found that ambient storage at 23±2°C, 68% RH for 12 weeks did not affect the bacterial load,  biogenic amines and lipids, and that the dried anchovy remained microbiologically safe and of good quality.