Tetracycline Resistance Genes in Salmonella enterica Serovars With Animal and Human Origin

Background: Tetracycline is one of the important antibacterial agents which is used against various bacterial infections. Different bacterial species and strains convey various tetracycline resistance (tetr ) genes. Objective: The present study was conducted to evaluate the occurrence of five tetr genes (tetA, tetB, tetC, tetD, and tetM) among Salmonella serovars obtained from humans and animals. Materials and Methods: A total of 60 different Salmonella strains previously recovered from humans, poultry, and animals were subjected to polymerase chain reaction (PCR) and sequence analysis of the genes. Results: In total, 6 strains were positive for the presence of tetA gene; three serotypes were also positive for the presence of tetC gene. The sequence analysis and phylogenetic tree showed similarities between the sequences of serovars in the present study and other Salmonella serovars and some other bacteria species in GenBank data. Conclusion: The results showed the great distribution of tetracycline resistance genes among Salmonella serovars with different sources which could be the effect of widespread use of the antibiotic particularly in the animals breeding farms

Isolation, Antimicrobial Resistance, and Virulence Genes of Thermophilic Campylobacter Species from Backyard Ducks in Amol, Northern Iran

Domestic poultry are considered natural reservoirs for the transmission of Campylobacter spp., mainly C. jejuni and C. coli, to other birds and humans. This study aimed to determine the Campylobacter infection status in backyard ducks in Iran. A total of 100 cloacal swabs were obtained from apparently healthy backyard ducks in different rural areas of Amol, a city in northern Iran. Bacterial isolation was based on traditional culture procedures, and genus and species identification were performed using an mPCR. All isolates were examined for antimicrobial resistance to seven antibiotics by Kirby Bauer’s disk diffusion test. The virulence-associated genes cadF, iamA, pldA, cdtA, cdtB, cdtC, and wlaN were detected as well. Out of the 27 Campylobacter isolates recovered, 19 (70.4%) were C. coli, and 3 (11.1%) were C. jejuni. The remaining five isolates (18.5%) were not identified. All (100%) isolates showed resistance to ciprofloxacin. Most isolates were resistant to ampicillin, tetracycline, and nalidixic acid. The resistance rate to amoxicillin-clavulanic acid and erythromycin was moderate but was relatively low to gentamicin. Moreover, over two-thirds of the isolates were MDR. All virulence genes, except iamA, were variably detected. The cadF and pldA genes had the highest (92.6%) and lowest (7.4%) positivity rates, respectively. In addition, a statistically significant association was observed between Campylobacter spp. and most of the critical virulence genes (p < 0.05). Our findings imply that backyard ducks should be paid attention to as a major source of human campylobacteriosis

The Effect of Sodium Alginate Coating Containing Citrus (Citrus aurantium) and Lemon (Citrus lemon) Extracts on Quality Properties of Chicken Meat

The effect of sodium alginate-based edible coating containing 2% citrus (Citrus aurantium) and lemon (Citrus lemon) extracts was evaluated on the chemical, antimicrobial, and sensory properties of samples during storage at 4°C. The results showed that coating with sodium alginate containing citrus and lemon extracts had a significant effect on the pH, TVN, PV, and TBA values of chicken meat (P<0.05). The lowest PV and TBA values were observed in the coated sample containing sodium alginate with 2% citrus and lemon extracts (ALG + CAE + CLE), indicating the antioxidant activity of sodium alginate and extracts. Coating resulted in less growth of microorganisms in the samples. The lowest microbial counts were also observed in the sodium alginate containing 2% citrus and lemon extracts (ALG + CAE + CLE). The coated samples had good overall acceptability similar to the control treatment. In conclusion, sodium alginate containing citrus (C. aurantium) and lemon extracts (C. lemon) are suggested for coating meat products

Appraisal of purple coneflower (Echinacea purpurea) extract on production performance, internal organs, and gut microflora of japanese quail

<div><p>ABSTRACT. An experiment was carried out to evaluate the effects of Echinacea purpurea (EP) extract at 5 levels (0, 0.25, 0.5, 1 or 2 mL L-1 of drinking water) on performance, internal organs and gut microflora of Japanese quail (Coturnix coturnix Japonica). The results showed that EP extract decreased feed intake and body weight gain of quails. The feed conversion ratio of quails fed with EP extract at the level of 0.5 ml L-1 drinking water was significantly decreased compared to the control group. Adding EP extract at the levels of 0.25, 0.5 or 1 mL L-1 drinking water decreased carcass yield of the birds (p < 0.05). The relative weight of internal organs of the birds fed different levels of EP extract was not significantly different. Birds consumed EP extract at the levels of 1 or 2 mL L-1 drinking water had lower ileal aerobic bacteria population compared to the control group; however, the ileal Coliform population increased by EP extract supplementation (p < 0.05). Results of the present study indicated that using EP extract at the level of 0.5 mL L-1 drinking water could improve feed conversion ratio of quails; however, it decreased the carcass yield of the birds.</p></div