This study aims at evaluating the effects of Zataria multiflora (Z. multiflora) essential oil (EO) on growth, aflatoxin production and transcription of aflatoxin biosynthesis pathway genes. Total RNAs of Aspergillus parasiticus (A.parasiticus) ATCC56775 grown in yeast extract sucrose (YES) broth medium treated with Z. multiflora EO were subjected to reverse transcription- polymerase chain reaction (RT-PCR). Specific primers of nor-1, ver-1, omt-A and aflR genes were used. In parallel mycelial dry weight of samples were measured and all the media were assayed by high-pressure liquid chromatography (HPLC) for aflatoxinB1 (AFB1), aflatoxinB2 (AFB2), aflatoxinG1 (AFG1), aflatoxinG2 (AFG2) and aflatoxin total (AFTotal) production. The results showed that mycelial dry weight and aflatoxin production reduce in the presence of Z. multiflora EO (100 ppm) on day 5 of growth. It was found that the expression of nor-1, ver-1, omt-A and aflR genes was correlated with the ability of fungus to produce aflatoxins on day 5 in YES medium. RT-PCR showed that in the presence of Z.multiflora EO (100 ppm) nor-1, ver-1 and omtA genes expression was reduced. It seems that toxin production inhibitory effects of Z. multiflora EO on day 5 may be at the transcription level and this herb may cause reduction in aflatoxin biosynthesis pathway genes activity.

Salmonella is widely distributed throughout the world and can be found in poultry industry, animal breeding centers, food and feedstuffs of all geographical regions. This study was conducted to determine and identify Salmonella serovars isolated from poultry, calves and foodstuffs (poultry and animals products such as egg and meat). A total of one hundred isolates of Salmonella serovars including Salmonella Typhimurium, Salmonella Enteritidis, Salmonella Infantis, Salmonella Gallinarum and Salmonella Pullorum consecutively were subjected to the conventional culture, biochemical and serological assays. The utility of molecular multiplex PCR was investigated to identify and differentiate among five Salmonella serovars which were identified according to the presence of rfbJ, fljB, invA, and fliC genes in S. Typhimurium, sefA, invA and spv genes in Salmonella Enteritidis, fljB, fliC and invA genes in Salmonella Infantis, hut and slgC genes in both Salmonella Gallinarum and Salmonella Pullorum and speC gene specifically in Salmonella Gallinarum. Biochemical assays and serotyping are complicated to directly differentiate between Salmonella Gallinarum and Salmonella Pullorum because of their antigenic similarity. According to the results, Multiplex PCR can be considered as simple, rapid, accurate and useful test to identify and differentiate among Salmonella serovars.

Disseminated candidiasis is a serious problem in public health that results from the invasion of Candida species, in particular Candida albicans. The aim of this study was to compare the efficacies of Zataria multiflora essential oil and itraconazole in clearing C. albicans from the visceral organs of BALB/c mice suffered from disseminated candidiasis. Zataria multiflora essential oil was extracted using Clevenger-type apparatus and analyzed by gas chromatography mass spectrometry (GC-MS). For clearance experiment, mice (20-25 g, N=8 per group) received essential oil at doses of 30, 48 and 64 mg/kg and itraconazole at dose of 200 mg/kg intraperitoneally (IP) 2 days before and after intravenous inoculation of 0.5 × 106 C. albicans blastospores. The treated animals were sacrificed on day 20, and 0.1 g of the tissue homogenates was plated onto specific media. In GC-Mass, the main components of the essential oil were carvacrol (61.29%) and thymol (25.18%). The results demonstrated that IP administration of 64 mg/kg of the essential oil had the highest efficacy in reducing C. albicans and produced 39.5, 21.8, 141.5, 174 and 501-fold reductions in mean CFUs per 0.1 gram in Candida infections of the liver, spleen, lungs, brain and kidneys, respectively, compared to positive control. Itraconazole showed significantly more responsiveness than the essential oil at dose of 30 mg/kg in clearing C. albicans from the kidneys (P<0.02), brain (P<0.02) and spleen (P<0.04), and less responsiveness than that of 64 mg/kg in clearing the organism from the brain (P<0.01), lungs (P<0.0005) and kidneys (P<0.0005), whereas no significant difference was observed between this drug and Z. multiflora at dose of 48 mg/kg. These data explain the increased rate of yeast clearance and reduced dissemination to the viscera of Z. multiflora treated mice.

In the present work, the effects of Zataria multiflora Boiss. essential oil (EO) against growth and citrinin production by Penicillium citrinum ATCC 1156 were evaluated in culture media and mozzarella cheese. The growth was completely inhibited at 200 ppm on potato dextrose agar, and minimum fungicidal concentration of the EO was estimated at 400 ppm. EO strongly suppressed the growth and citrinin formation in media with a dose‐dependent manner. At 200 ppm in yeast extract sucrose (broth) flasks, mycelial dry weight and citrinin production significantly reduced by 87.5 and 92.4%, respectively (P < 0.05). The EO at all concentrations had an inhibitory effect against fungal growth and citrinin production by P. citrinum in mozzarella cheese but no concentration of EO tested was able to absolutely prevent the fungal growth and citrinin production in mozzarella cheese. It is concluded that this EO could be safely used as a preservative material on some kinds of food such as cheese to protect them from fungal contaminations. Practical Applications The significant (P < 0.05) inhibitory effect of the essential oil (EO) on growth and citrinin production by Penicillium citrinum presented in this study can propose the use of the EO as an antifungal compound in the food industry.

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Avian infectious bronchitis virus (IBV) is causing major economic losses to the poultry industry. The analysis of the S1 gene has been used to determine IBV genotype. The aim of this study was genotyping of IBVs circulating among the Iranian broiler flocks in the period between 2015 to 2017. Trachea samples from 278 broiler flocks were collected from broiler farms in eight provinces of Iran. After Real-time RT-PCR, IBV-positive samples were further characterized based on S1 gene. The results of the Real-time RT-PCR showed that 52.16% of flocks were IBV positive. Four genotypes were detected and the frequency of occurrence rates of IS-1494-like, 793/B, QX and Massachusetts IBV genotypes were 70.34%, 19.31%, 7.58% and 2.75%, respectively. Sequence analysis revealed that nucleotide identities within IS-1494-like group ranged between 98.86-100%, while each of the QX, Massachusetts and 793/B groups were 98.05-100%, 98.20-100% and 93.29-100% respectively. These results show that the IS-1494-like IBV is the dominant IBV genotype in Iran. Proper control strategies are essential to overcoming the high frequency of occurrence of IS-1494-like IBV. The phylogenetic relationship of the strains with respect to different sequences and geographical regions displayed complexity and diversity. Further studies are needed and should include the isolation and full-length molecular characterization of IBV in Iran.

Brucellosis is a worldwide bacterial zoonosis caused by Brucella spp. No approved vaccine is available for human use against the disease. In this study, outer membrane vesicles (OMVs) from a Brucella melitensis biovar 1 human isolate obtained in Iran were used to immunize BALB/c mice (n = 12) by 2 intramuscular injections with a 2‐week interval. Another group of 12 mice was used as non‐vaccinated controls. Two weeks after the last vaccination, six mice of each group were sacrificed, and proliferation and interferon gamma (IFNγ) production responses of their splenocytes were evaluated following in vitro stimulation with killed Brucella cells. The other mice were challenged with the virulent B. melitensis isolate. Two weeks later, mice were killed and spleens were cultured to determine the number of the challenge strain. The results showed proliferative response and IFNγ production of splenocytes from vaccinated mice (stimulation index: 2.18 ± 0.57, and 1519.35 ± 10.70 pg/mL, respectively) were significantly higher than those of control mice (stimulation index: 1.02 ± 0.02, and 210.01 ± 17.58 pg/mL, respectively). Numbers of the challenge strain in spleens of vaccinated mice were also significantly less than those in the controls with 1.6 units of protection. Our study revealed vaccination with OMVs of the B. melitensis isolate could induce specific immune responses and protection against infection in the mouse model suggesting their potential application for active immunization against brucellosis.

Infectious bronchitis virus (IBV) is one of the major threats to the poultry industry, with significant economic consequences. Despite strict measures, the disease is difficult to control worldwide. Experimental evidence demonstrates that the severity of IBV is affected by the genetic background of the chicken, and the selection of appropriate breeds can increase production efficiency. Therefore, the aim of the present study was to assess the strength of the immune response to IBV in tracheal tissues of Ross 308 and Cobb 500 broiler chickens by evaluating transcriptome changes, focusing on immune responses and the viral load in tracheal tissues two days after IBV infection. We identified 899 and 1350 differentially expressed genes (DEGs) in the Cobb 500 and Ross 308 experimental groups compared to their respective control groups. Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis indicated the involvement of signaling pathways (Toll-like receptor [TLR], NOD-like receptor [NLR], and RIG-I-like receptor [RLR] signaling pathways). Interestingly, the RLR signaling pathway appears to be affected only in the Cobb hybrid. Furthermore, the viral loads in tracheal samples obtained from the Ross challenged group were significantly higher than those of the Cobb challenged group. The results of this study indicated that the host transcriptional response to IBV infection as well as the viral load can differ by hybrid. Furthermore, genes such as TLR-3 , ChIFN-α , MDA5 , LGP2 , IRF-7 , NF-κB , and TRIM25 may interfere with IBV proliferation. Supplementary Information The online version contains supplementary material available at 10.1007/s00705-021-05322-5.