JOURNAL OF VETERINARY MICROBIOLOGY
Year:2019 | Volume:15 | Issue:1(پیاپی 38) |Papers Count:16

Achillea millefolium is one of the oldest known medicinal plants, due to the presence of certain chemical compounds are used traditional and modern medicine. One of the most important medicinal properties of Yarrow, its antimicrobial effects on a wide range of pathogens in humans and animals. The in vitro antimicrobial and antioxidant activities of the essential oil from leaves of Achillea millefolium subsp. millefolium were examined. GC-MS analysis of the essential oil resulted in the identification of fifty-eight compounds constituting 98. 71% of the total essential oil of leave. The essential oil of leaves were characterized by a high number of monoterpenes borneol (12. 32%), 1, 8-cineole (10. 51%), β-pinene (9. 33%) and α-pinene (8. 82%). Regarding anti-oxidation, the investigated essential oil from leaves strongly reduced the diphenylpicrylhydrazyl radical (IC50=0. 94 mg/ml). This essential oil showed antimicrobial activity as well against Staphylococcus aureus, Salmonella enteritidise, Escherichia coli, Penicillium glaucum and Saccharomyces cervesiae (MIC values 0. 45-7. 20 mg/ml). This study confirms that the essential oil from leaves of Achillea millefolium possessed antioxidant and antimicrobial properties in vitro.

The study was carried out to determine the reducing microbial load status of broiler carcasses throughout of cold water chilling, hydrogen peroxide solution and ozone therapy. A total number of 45 broilers carcasses from automatic poultry slaughter plant in Chaharmahal and Bakhtiari Province taken from one batch (The same flock) and it was expected to have a high degree of similarity after complete preparation (Slaughtering-scalding-defeathring evisceration) and just before placing in the chillers. Fifteen carcasses were placed in the ordinary chiller containing cold water for 60 min, other 15 were placed in another similar chiller containing aqueous solution of 0. 2% hydrogen peroxide and others were treated by ozone (7 mg per min) for the same time period. Total colony count, mould and yeast count, coliform count and Staphylococcus aureus counts were determined in all groups. The reduction percent in the microbial counts were detected. The result showed that highly significant reduction in the numbers of total colony count, coliform count and Staphylococcus aureus count and non significant decrease in the total mould and yeast count in comparison with the untreated ones. Data from this study showed that hydrogen peroxide and ozone therapy induced microbial. Additionally illustrate a very high reduction percent in the total counted colonies, coliform count and Staphylococcus aureus count and little reduction in the total mould and yeast count as a result of addition of hydrogen peroxide into the water used for chilling broiler carcasses. It was concluded that hydrogen peroxide and ozone therapy indicate superior activity as a powerful and versatile sanitizer for poultry carcass.

Present study was designed in order to molecular confirmation, capsular typing and detection of 12 important virulence factors include ompH, oma87, sodA, sodC, hgbA, hgbB, exBD-tonB, nanB, nanH, ptfA, pfhA and toxA in 18 Pasteurella multocida avian isolates from different areas of Iran with a strain of the organism was isolated from the epidemic pasteurellosis in the Northern region, and also survey of acute isolates lethality in poultry embryos and pullet. Molecular confirmation of tested isolates was performed using specific primers of kmt1. As well, capsular typing and detection of virulence factors of isolates were performed by application of multiplex PCR method and using specific primers of capsule biosynthesis genes and genes encoding virulence factors of organism. All isolates were confirmed molecularly but based on the results of capsular typing, 16 (88. 8%) isolates with strain isolated from epidemic pasteurellosis were identified as type A and 2 (11. 1%) as untypeable isolates. Detection of virulence genes showed that all studied isolates has six virulence genes of sodC, hgbA, hgbB, nanB, nanH and ptfA. The oma87, exBD-tonB, ompH, sodA and pfhA genes were respectively present in 94. 4, 94. 4, 83. 3, 66. 6 and 27. 7% of the isolates, but there was not any toxA positive isolates. To determine the chicken embryo lethal dose 50 (CELD50) and lethal dose 50 (LD50) of the isolates, different dilutions of five acute isolates containing the majority of virulence genes as well as strain isolated from epidemic pasteurellosis were respectively inoculated to embryonated chicken eggs and lying pullets. Based on the results of CELD50, though all six isolates were able to waste the poultry embryos, but strain isolated from epidemic pasteurellosis was recognized as the most acute isolate. Results of LD50 test showed that none of the five acute isolates were able to waste the studied pullets while the LD50 of strain isolated from epidemic pasteurellosis was determined 5 × 101 colony forming unit per bird (cfu/case), and this strain was identified as the most acute understudy isolate. The findings of this study showed that, despite the presence of the majority of virulence genes in P. multocida avian isolates in Iran, and that the most acute isolates were able to waste the poultry embryos but they were not infectious to lying pullets, and virulence of strains isolated from birds with hyperacute form of the disease is far higher. Our data could be useful in the design of new and efficient vaccines that would be acceptable protection in animal populations.

The aim of the present study was to evaluate the antimicrobial effects of aqueous, ethanol, methanol, acetone, chloroform and ethyl acetate extracts of Aloe vera leaves on two fish infectious bacteria, Vibrio cholerae and Listeria monocytogenes. The Aloe vera extracts obtained through rotary apparatus and V. cholerae and L. monocytogenes provided from Iranian fungi and bacterial collection. Minimum bactericidal concentration (MBC) and minimum inhibitory concentration (MIC) of the extracts were determined using dilution in well method. Moreover, the diameters of inhibition zones was determined through disk diffusion method. Results of this study showed while aqueous extract of Aloe vera had inhibitory and lethal effects on L. monocytogenes, but have no influence on V. cholerae. The most inhibitory and lethal characteristics of studied extracts on both bacteria was due to chloroform solvent, while had more influence on L. monocytogenes. Chloroform extract tend its inhibitory property even in the most diluted form. Like inhibitory properties, the biggest diameters of inhibition zones was from chloroform extract against L. monocytogenes. Acording to edibility of Aloe vera, its availability and reasonable value, it is possible to use Aloe vera as an alternative for conventional antibiotics and chemical disinfectants in aquaculture rearing pools.

Lactococcus garvieae, the causative agent of lactococcosis, is one of the most important fish pathogens all around the world. The aim of this study was to investigate the inhibitory effects of Satureja bachtiarica and Satureja khuzestanica essential oils against the expression of capsule gene (epsD) of L. garvieae. Bacterial isolates containing epsD gene were exposed to the minimum inhibitory concentrations of the essential oils (0. 12 μ l/ml) and the expression of epsD gene was investigated by real-time PCR. The results showed that the expression of epsD gene was suppressed in the studied bacterial isolates under MIC concentration of the essential oils. The results also revealed that the gene expression was decreased by increasing the essential oil concentration. However, S. khuzestanica was more effective on the expression of epsD gene than S. khuzestanica. Therefore, the use of S. bachtiarica and S. khuzestanica essential oils can be recommended to prevent lactococcosis in aquaculture via suppression of capsule gene.

Bacterial microflora in water and fish body surface has an important role for fish bacterial diseases outbreak and are known as secondary bacterial infections. These bacteria can be pathogenic and develop high mortality in stress conditions. In this study, samples were collected from body surface and gills of 70 rainbow trout (300-500 g) in seven fish farms on Haraz road between Larijan and Poloor regions by sterile swabs. Water resource was Haraz River. Skin and gill swabs were transferred to the lab in capped tubes containing sterile PBS (Phosphate Buffer solution), individually and were cultured in TSA (Tryptic Soy Agar), Plate Count Agar and MacConkey Agar media. Each sample were cultured in two TSA medium plates for conserving in aerobic and anaerobic conditions in 25° C, and one MacConkey Agar plate to reassure of gram negative bacteria absence. Plate count agar culturing was applied for mesophilic and psychrophilic bacteria isolation in 13 and 37° C. Nine bacterial species were isolated from gills and fish body surface (including: E. coli, Staph. areus, Staph. saprophyticus, Staph. epidermidis, Bacillus cereus, Aeromonas hydrophila, Proteus mirabilis, Pasteurella multocida, Psuedomonas aeruginosa). E. coli were identified in all samples. There was no significant difference between gills and skin in all facilities (P>0. 05). Among the facilities, there was no significant difference between isolated bacterial species (P>0. 05). Except E. coli that was identified in all farms, and irregularity frequency for P. aeruginosa in farms, in other cases, bacterial frequency increased up to downstream fish farms. Isolation of such bacteria may be an indicator for urban and home waste water contamination.

Toxoplasma gondii is an obligatory intracellular protozoan which can infect broad spectrum of warm blooded animals as intermediate hosts. Cats are definitive hosts. Seroprevalence of this parasite among birds is an effective criterion for environmental contamination to Toxoplasma oocysts. In this research, T. gondii Immunoglobulin G (IgG) were detected by ELISA in 168 broilers sera which were referred to Semnan industrial abattoir and 30 freerange chicken sera which were collected from different places in Semnan. 39. 9% of broilers and 96. 7% of free-range chickens were positive in Toxoplasma IgG antibody. There was significant difference between two different groups in Chi-square test (P<0. 0001). According to the results, seroprevalence of Toxoplasma is relatively high among chickens in Semnan. In free-range chickens, soil contamination to the parasite oocysts and in broilers some management problems and cat access as a definitive host to the water and food supply of chickens can effective on high prevalence of the infection.

Abstract In this article; 42 repeated breeders (test group), and 18 healthy (control group) and on heat Holstein cows were prepared in a farm of Khorasan-Razavi province. Their blood samples were obtained from the coccygeal vein and the isolated serum samples were frozen and sent to a laboratory, together with the heat discharge samples. In the laboratory; estradiol concentrations of serum samples were determined with RIA technique, and microbiology and the other discharge characteristics were determined grossly (transparency and stretching levels), or with a light microscope (fernization and crystals regularity). Results showed that; the mean of stretching levels (cm) (3. 15± 0. 2, 3. 25± 0. 3, 3. 1± 0. 4, 3. 3± 0. 3, P=0. 9), the median of simple fernization (2. 5, 3, 2, 3, P=0. 3), the median of fernization levels evaluated with Photoshop software (3, 3, 4, 4, P=0. 1), the crystals regularity (2, 2, 2, 2, P=. 85), the median of levels of transparency (2, 1. 5, 2, 2, P=0. 06), the mean of concentrations of estradiol-17-β (pg/ml) (8± 2. 4, 4. 7± 1. 7, 4± 1. 5, 5. 3± 0. 3, P=0. 7) were determined in non-pregnant (N=34) and pregnant (N=8) repeat breeder, and non-pregnant (N=10) and pregnant (N=8) normal cows, respectively. Spearman correlation test showed only a significant correlation between fernization levels evaluated with Photoshop software and different (test and control) animal groups (r=-0. 3, p=0. 017). So that the third degree of fernization (equivalent to 40-60% of fernization) was considered the best degree, and the lower or the higher than it considered as unsuitable degrees. There was no significant correlation between the result of microbiologic findings and fernization, transparency, stretching levels and crystals regularity (P>0. 05). However, E. coli, Klepsiella, Trueperella pyogenes and beta-hemolytic Staphylococci were significantly more isolated from repeat breeder cows (P=0. 00). It was concluded that only the middle fernization level evaluated with Photoshop software was associated with pregnancy rate.

One of the important factors causing the loss of fish eggs in the hatcheries is contamination with Saprolegnia parasitica. Today, Green Malachite is the most widely used drug against this fungi, which has been confirmed to be carcinogenic. The aim of this study is to investigate the antifungal effects of Matricaria chamomilla and Achillea officinolis extracts to control of infected rainbow trout eggs with Saprolegnia parasitica in comparison with Green Malachite. In this study minimum inhibitory concentration (MIC) and minimum fungicidal concentration (MFC) were mesured by Micro Broth Dilution test and the growth of fungi in a solid medium, and determined as 100 and 150 mg/mL for M. chamomilla and 150 and 200 mg/mL for A. officinolis, respectively. The eggs of rainbow trout were divided into four treatments (control, two plant extract and Green Malachite treatments) and were exposed with MFC of each extract and 1 mg/L Green Malachite for 1 hour/day during incubation period. The mortality of eggs were compared in stages of fertilization to sighting, sighting to hatching and total incubation period. The results showed that the mortality of eggs in each stage in Green Malachite treatment was significantly lower than control and A. officinolis (p˂ 0. 05), but did not show difference with M. chamomilla treatment (p>0. 05). The lack of significance difference of mortality and hatching percentage in M. chamomilla (75. 90± 0. 26%) compared to Green Malachite (77. 97± 2. 32%) showed that M. chamomilla extract with antifungal effects is a suitable natural remedy for replacing Green Malachite in fish eggs hatcheries.

Escherichia coli is one of the most important bacterial pathogens of human and poultry. Avian pathogenic Escherichia coli (APEC) and uropathogenic Escherichia coli (UPEC) isolates cause diseases outside intestine environment. These strains share some common traits. It has been suggested that transfer of these commonalities between different hosts is of importance in the epidemiology of disease in poultry and human. In the present study, presence of 4 virulence associated genes (sitA, iutA, traT, and tsh) were investigated among 26 APEC and 25 UPEC isolates by polymerase chain reaction (PCR) assay. Statistical analysis was also carried out using minitab 15. The frequencies of the presence of these selected genes in APEC and UPEC isolates were 96. 2% and 64% for traT, 88. 5% and 76% for sitA, 84. 6% and 68% for iutA, and 61. 5% and 16% for tsh, respectively. traT and sitA were the most prevalent genes among APEC and UPEC isolates, respectively. Diverse combinations of virulence associated genes were also detected among these strains. Combinations of virulence genes of iutA-sitA-tsh-traT and iutA-sitA-traT were the most frequent in APEC and UPEC isolates, respectively. It supports possibility of virulence genes transfer between poultry and human. Further studies are needed to ascertain the importance of such possibilities in the epidemiology of the infection in human and poultry.

Infectious bronchitis virus (IBV) is the cause of acute respiratory viral disease in poultry with respiratory rats and coughing and sneezing. Corona viruses are created a wide range of respiratory, intestinal, liver and nervous disease with different virulence in cats, dogs, pigs, rodents, cows, birds and human. Corona viruses are able lots of recombination's and mutations. This ability gives them the opportunity to be active in different hosts and different climatic conditions, such as avian infectious bronchitis disease in poultry that can cause losses in broilers. S1 gene sequencing is used for molecular epidemiology and genotype characteristics of infectious bronchitis virus. For better understand the molecular epidemiology of infectious bronchitis virus in Iran, the IBVs gene isolates of broiler poultries from Ardebil province were sequenced in this study. A total of 30 tracheal swabs were collected from broilers in random in Ardebil province in 2016. For detection and genotyping of virus, RNA extraction was performed using RNA extraction kit. RT-PCR was used in one process for the production of cDNA, and then, RT-PCR product were amplified to identify infectious bronchitis virus using Nested-PCR with primers encoding 5’ UTR, then, for genotyping of positive samples, gene sequencing of spike glycoprotein was performed 70% of tracheal swabs were positive and strain identification was done according to existing protocols. It can be concluded that the corona virus is spinning among broiler flocks in Iran. In this study, extraction and RT-PCR on suspected positive samples was repeated several times. During the test two negative controls was used including extraction negative control and RT-PCR negative control. Genetic analysis based on the highly variable nucleotide sequence of S1 gene showed that, the overall rate of infection was 70% and detected three genotypes in this area: Variant 2 (IS/1494), 793/B and MASS and QX overall percentages in respectively 52/3%, 33/5%, 9/5% and 4/7%.

Avian Adenoviruses are widely distributed in commercial flocks in the world and show wide variety of virulence and clinical signs. Some of isolates of fowl adenoviruses can cause Inclusion Body Hepatitis (IBH). The importance of IBH agents are economic losses and its association with other viral diseases. Immunosuppression after Infectious Bursal Disease (IBD) can facilitate disease of IBHV. Also simultaneous infection with chicken infectious anemia virus (CIAV) and IBH increase the heart injuries and mortality. Mortality rate in IBH can reach to 10% but sometimes it can be over 30%. In this study identification of IBHV by PCR method and presence of Hexon gene in variable area of Loop1 was studied in Isfahan province for the first time. 69 liver samples from suspected 35 flocks and cities gathered and sent to laboratory. Five samples from Kashan, Ardestan and Golpayegan were positive in PCR. So presence of IBHV confirmed in this province.