First Isolation of Bacillus licheniformis from Bovine Mastitis in Iran.

Bacillus licheniformis is a gram-positive, endospore-forming, saprophytic and facultative anaerobe that is resistant to heat and environmental conditions. This study was the first to isolate and confirm B. licheniformis as a cause of bovine mastitis in Iran. In the summer of 2020, 105 samples of mastitic milk were collected from dairy farms around Tehran and sent to the microbiology laboratory of the Faculty of Veterinary Medicine at the University of Tehran. The bacterial pathogens were identified using selective and differential culture media and confirmed by PCR to contain the toxin synthetase genes licA, licB and licC in mastitic isolates of B. licheniformis. Resistance patterns to 19 antibiotics were determined for two isolates of B. licheniformis. Staphylococcus aureus and Escherichia coli were identified as the most important organisms in the samples. B. licheniformis was isolated from the two samples containing all three genes. Both isolates were resistant to streptomycin, trimethoprim-sulfamethoxazole, cefixime, ampicillin, bacitracin, clindamycin, and gentamicin. B. licheniformis was reported for the first time in Iran as a cause of bovine mastitis with clinical symptoms. The first isolation of toxin-producing strains of B. licheniformis from mastitic cows in Iran raises concerns about the safety of dairy products. In principle, selected strains with toxigenic potential should not be used as feed additives and animal feed. However, whole genome sequencing is proposed to search for genes coding for toxins.

Clonal relatedness and antimicrobial susceptibility of Salmonella serovars isolated from humans and domestic animals in Iran: a one health perspective.

Background: Salmonellosis is one of the most important zoonotic diseases in humans and animals worldwide. Aims: The main objective of this study was to report serovars, clonal relatedness, and antimicrobial resistance of Salmonella strains isolated from human, different animal hosts including pigeons, broilers, cattle, camel, parrots, and hamsters in different regions of Iran. Methods: Twenty-four Salmonella isolates were confirmed at the genus level by biochemical tests and polymerase chain reaction (PCR) by showing the presence of invA gene. Serovars were determined and their clonal relatedness was assessed by RAPD-PCR and antibiotic resistance profiles. Results: Overall, Salmonella Typhimurium was the most prevalent serovar (45.8%, 11/24), which was recovered from humans, pigeons, and camels. Salmonella Enteritidis (29.2%, 7/24) was the second common serovar that was recovered from cattle, broilers, humans, and hamsters. Salmonella Infantis (12.5%, 3/24) belonged only to broiler sources, and Salmonella Seftenberg (12.5%, 3/24) was isolated from eggs and a parrot. The major RAPD pattern was VI (33.3%) in which the two S. Typhimurium isolates (belonged to humans and pigeons) exhibited similarity in both RAPD pattern and resistance profile. Antimicrobial susceptibility test showed full resistance to tylosin and erythromycin (100%, 24/24). All isolates (100%, 24/24) were susceptible to ceftriaxone, cefixime, and gentamicin. In total, 75% of the isolates were multi-drug resistant (MDR) and revealed 15 different antimicrobial resistance profiles (R-type). Conclusion: This study supports the potential transmission of Salmonella serovars via animal contacts. Thus, it is necessary to establish a national systematic monitoring program with one health approach for controlling Salmonella infections.

Distribution of Antibiotic Resistance Genes among the Phylogroups of Escherichia coli in Diarrheic Calves and Chickens Affected by Colibacillosis in Tehran, Iran.

Antibiotic resistance occurs in the endogenous flora of exposed population in addition to pathogenic bacteria. This study was conducted to evaluate the distribution of antibiotic resistance genes among 63 isolates of Escherichia coli of Escherichia coli (E. coli) in diarrheic calves and poultry. According to the results, B1 and B2 were the most prevalent phylogroups of E. coli in calves and poultry carcasses, respectively. Antimicrobial resistance was observed in 76% of the isolates, and 62% of the strains were multi-drug resistant. Antibiotic resistance in E. coli strains obtained from calves strains was significantly higher than those obtained from poultries. Additionally, the strains of B1 and D phylogroups had the highest and lowest antimicrobial resistance, respectively. At least one encoding gene for integrone was detected in 23 strains (36.5%) and Class I integron had the highest prevalence. Accordingly, this study gave baseline information on the magnitude of the resistance problem and its genetic background in E. coli from domesticated animals of the Tehran, Iran. Moreover, the power of oligonucleotide array technology in the discrimination of different genotypes during a short time was confirmed in this study.

Molecular identification of Salmonella Infantis isolated from backyard chickens and detection of their resistance genesby PCR.

This study aims at molecular identification of Salmonella Infantis isolated from backyard chickens and the detection of their antibiotic resistance genes. A total of 46 Salmonella-suspected samples isolated from backyard chickens of northern Iran were collected. Serotyping was done by the traditional method and then confirmed by PCR. Antimicrobial susceptibility of the isolates against 13 antimicrobial agents was determined by the standard disk diffusion method. There were 44 samples identified as Salmonella. Serotyping results showed that all 44 isolates belonged to serogroup C1 and serovar Infantis. The most resistance observed was to tetracycline and doxycycline (100%), chloramphenicol (79%) and florfenicol (72%). The floR, catI, tetA and tetG genes were used for the detection of florfenicol chloramphenicol and tetracycline resistance. In order to identify the phenotypic resistance in strains which showed resistance genes by PCR, colony PCR and culture on plates each containing antibiotic was performed simultaneously. All the Salmonella Infantis resistant to florfenicol and chloramphenicol harbored floR and catI. None of the Salmonella resistant to tetracycline carried tetA or tetG. The result of colony PCR and culture in antibiotic medium confirmed the results of PCR and indicated phenotypic resistance in these samples.

Anti-Candida zeylanoides activity of some Iranian plants used in traditional medicine.

OBJECTIVE: To assess anti-Candida zeylanoides activity of the essential oils (EOs) of five Iranian medicinal plants and to determine the different components of the EOs. METHODS: Anti-C. zeylanoides effects of the EOs and reference drugs were determined by disc diffusion method. The EOs from Trachyspermum copticum, Zataria multiflora, Nigella sativa, Ziziphora clinopodiodes and Heracleum persicum were analyzed by gas chromatography/mass spectroscopy (GC/MS). RESULTS: The mean values of inhibition zones were found to be more than 60mm for T. copticum, 56.7 mm for Z. multiflora, 40.8mm for N. sativa, 33.7 mm for Z. clinopodiodes and 18.7 mm for H. persicum. In GC/MS analysis, thymol (63.4%), carvacrol (61%), trans anthol (39%), pulegone (37%) and hexyl butyrate (30.2%) were found to be the major components of T. copticum, Z. multiflora, N. sativa, Z. clinopodiodes and H. persicum, respectively. CONCLUSION: The EOs showed strong anti-C. zeylanoides activities, which strengthen the potential use of these substances for the treatment of candidiasis.