نشریه تازه ها در میکروب شناسی دامپزشکی
سال سوم شماره 1 (بهار و تابستان 1399)

Throughout human history, many infectious diseases have traditionally been treated with herbal medicines, so today, in many developing countries, herbal medicines play a major role in early treatment. The purpose of this study was to investigate antimicrobial effects of ethanol, methanol, ethyl acetate Citrullus colocynthis (Fruit) and Teucrium polium (Leaf) on some pathogenic bacteria. The plants were collected from Zabol city, then milled and placed in solvents of ethanol, methanol, ethyl acetate, and finally, extraction was carried out using a rotary machine. The bacteria were prepared as standard and the minimum inhibitory concentration and minimum destructive concentration were determined by micro-dilution method. The lowest inhibitory concentrations of ethanolic extract (12.5 ppm), methanol (25 ppm) and ethyl acetate (25 ppm) of Citrullus colocynthis, respectively, on the bacteria Listeria monocytogenes, Vibrio chlora and Bacillus cereus they have been effective. The ethanolic extract of Teucrium polium with a minimum concentration of 50 ppm was only able to inhibit the bacterium Vibrio cholerae. The lowest inhibitory concentration of chloroprene methanolic extract of Teucrium polium with 25 ppm was observed against Vibrio cholerae bacteria and the bacterium Bacillus cereus grew at all concentrations. The lowest inhibitory concentration of ethyl acetate extract of Teucrium polium was observed with 12.5 ppm on vibriochlora bacteria. In general, ethanolic extracts of Citrullus colocynthis have been on Listeria monocytogenes bacteria and Ethyl acetate extract of Teucrium polium on Vibrio cholerae, so it is recommended to use a special type of plant with the most effective solvent depending on the purpose of using herbal extract.

Lactobacillus reuteri is a probiotic bacteria thatproduces, a wide-range of antimicrobial substance, “reuterin” in the presence of glycerol. The present study was aimed to evaluate the efficacy of Lactobacillus reuteri against the growth of Fusarium oxysporum. So, the cell-free culture supernatant (CFCS) of Lactobacillus reuteri was prepared by centrifugation (8000 rpm for 15 min) of bacterial overnight culture, with and without 2% glycerol medium. Inhibition effects, evaluated by two methods micro-well dilution (both of CFCSs: two-fold dilution series (100, … 6.25 µl); 10 µl fungal spore suspension (2×106 spores/ml); PDB medium) and Tube culture (both of CFCSs: (80, 60 µl); 10 µl fungal spore suspension (2×106 spores/ml); SDB medium).The minimum inhibitory concentration (MIC) and minimum fungicidal concentration (MFC) of CFCS obtained from glycerol-medium, was determined as 60µl. The CFCS obtained from glycerol-free medium had no inhibitory effect on F.oxysprom growth. The results of the present study revealed that the CFCS of Lactobacillus reuteri obtained from medium with 2% glycerol, probably due to the presence of reuterin, is able to inhibit the growth of toxigenic Fusarium oxysporum and can be used in the feed and food industry as a potential bio-controller against toxigenic Fusarium species.

Infectious pancreatic necrosis is caused by IPNV virus that represented by various strains with different virulence linked to some motifs of the VP2 capsid. In this study (2018-2019), we screened some suspected Iranian trout farms for IPNV, and the genotype and virulence motifs of the positive samples were characterized. The causative agents of two outbreaks in trout farms of Kermanshah and Hamedan provinces in Iran were diagnosed as IPNV by RT-PCR assay. Phylogenetic analysis of VP2 gene revealed the detected IPNV isolates belonged to the Genotype 5 (Sp serotype) with close identity (> 99%) with European, Turkish, as well as previously reported Iranian isolates. Characterization of VP2 from both outbreaks has also shown the detected isolates have proline and threonine at amino acid residues 217 and 221, respectively, which are associated with low pathogenicity. In conclusion, the IPNV isolates from some Iranian trout farms (Kermanshah and Hamedan provinces) are of Sp serotype (Genotype 5) that despite P217T221 motif show moderate virulence, and may have originated from Europe via eyed eggs.

Garlic has therapeutic and also antibacterial properties and its inclusion in broiler diets improves their feed efficiency and lowers their mortality rates.The present research intended to evaluate the effects of freshly dietary garlic cloves on the intestinal Escherichia coli population and some blood serum biochemical factors in broilers. In this study, one hundred and five day-old broiler chicks were used in Zabol. On the seventh day of age, sick birds removed and 96 chicks with better body condition were selected and randomly divided into 3 equal groups with 2 replicates. Groups 1, 2 and 3 (the control and treatment groups) received 0, 1 and 2 percent of fresh crushed garlic cloves in their diets, respectively. When the broilers were 35 days old, 8 chicks from each replicate were selected randomly, weighed and blood samples were taken from the wing veins. They were then slaughtered and their bursa of Fabricius was removed and weighed. Their ileum contents were used to determine the E. coli population. Results indicated that bursa of Fabricius weight increased in broilers receiving fresh crushed garlic cloves in their diets compared to the control group (P<0.05). There was not significant differences on E. coli population, cholesterol, triglyceride and total protein between the groups (P>0.05).

Nosocomial infection is considered as one of the major and most basic medical problems in all hospitals and affects an average of 5 to 10% of hospitalized patients. Exacerbating factors of nosocomial infections include frequent use of tools as well as repeated contacts with medical staff. In this study, the antibacterial effects of copper nanoparticles using aqueous extract of Ganoderma lucidum on standard strains of Staphylococcus aureus, Acinetobacter baumannii and Streptococcus pyogenes and Pseudomonas aeruginosa Which are the cause of nosocomial infections were investigated. electron microscopy was used to measure the dimensions and shape of copper nanoparticles. Infrared spectroscopy was also performed to investigate possible organic compounds that could be involved in the synthesis of nanoparticles. Also, to observe the effectiveness of this nanocomplex, MTT test was performed on two vero cell lines and L 929 fibroblast cell line. The results of scanning electron microscopy in this study showed that the sample of the extract in morphology is completely uniform. Copper nanoparticles are spherical and in the range of 20-30 nm. Also, in the study of mtt test, ANOVA test showed that the value of Sig is zero, which indicates a significant difference between different concentrations and positive and negative control samples. According to the results of this study, fungal and copper nanocomplexes had a relatively strong antibacterial effect against bacteria that cause nosocomial infections. The non-toxicity proposal of copper nanoparticles should be investigated in laboratory spaces in order to use the antibacterial properties of these nanoparticles in human applications.

Recently, studies have been conducted to use plant compounds as natural preservatives in foods. So, the objective of this study was first to evaluate antimicrobial activity of ethanolic and methanolic extracts of Aloe vera, German chamomile and Mentha piperita L cultivated in Medicinal plants farm of agricultural research institute of zabol university, against spoilage and pathogenic microorganisms associated with pasteurized milk including Pseudomonas aeruginosa, Bacillus cereus, Micrococcus luteus, listeria monocytogenes and Escherichia coli and the next stage was to investigate the impact of ethanolic extracts of aloe vera and German chamomile on the shelf life of pasteurized milk. The results indicated that Aloe vera had the most antimicrobial activity followed by German chamomile and Mentha piperita L respectively (P<0.05). In general, the ethanolic extract of studied plants was found to posses more powerful antibacterial activity than methanolic one (P<0.05). Ethanolic extracts of Aloe vera and German chamomile were evaluated as natural preservatives at concentrations of 0.15, 0.3 and 0.6 (% v/v). The results revealed that the treatments of pasteurized milk with 0.3% and 0.15% of German chamomile and also Aloe vera with a concentration of 0.3% with acceptable sensory properties had a significantly lower total microbial count and longer shelf life compared to the control sample. Therefore, this study confirmed the possibility of usingof the extract of mentioned plants as a preservative in pasteurized milk besides its beneficial properties of a functional food.

Abortion in domestic animals has always been considered as one of the problems of the livestock industry in all parts of the world, whose causes are numerous and varied. Streptococcus equi subspecies zooepidemicus is a gram positive coccus and negative catalase which is one of the most important causes of abortion and loss of  foal during pregnancy in mare. The aim of this study was to investigate the presence of  DNA of this bacteria in a number of mare abortion fetuses  in western provinces of Iran. For this purpose, 125 samples of aspirated stomach contents of the aborted fetuses were tested by PCR method to detect the sodA gene. The results of this study showed that 23 (18.4%) of 125 aborted fetuses were infected with Streptococcus equi subspecies zooepidemicus. The findings of this study indicate a high incidence of  Streptococcusis  infection and showed that one of the most important factors in abortion in mares that control programs to reduce the economic losses of this bacteria in Iran is necessary. In this study, for the first time, a bacteria in the contents of the stomach of aborted fetuses of mares  were identified as One of the main causes of abortion in Iran.

Poultry red mite, Dermanyssus</em>gallinae</em>, is the most important haematophagus ectoparasite in layer and breeder flocks in many countries. Infestation with this obligate parasite, is very common and according to the epidemiological reports, 83 percent of the European farms are infested with this parasite. Also, D. </em> </em>gallinae</em> has been described as the most prevalent and important pest of poultry in Iran. Infestation with red mite can lead to reduced egg production, stress, immunosuppression, feather pecking, cannibalism, anaemia and death. Besides, It has been established that this mite can transmit some pathogens like Salmonella</em>. Furthermore, infestation of human with D. gallinae</em> has been increasingly reported from different countries, including Iran. Although diverse methods have been reported for control of this mite in poultry houses, the main approach has been relied on the use of synthetic acaricides. The objectives of this review study were to investigate the various aspects of the D. gallinae</em> infestation, describe different acaricides and evaluate the effects of each acaricide on this parasite.

Cheese lymphadenitis is a very common skin infectious disease among sheep and goats around the world caused by the bacterium Corinne bacterium Pseudotuberculosis. The development of this disease among livestock always causes significant economic losses. In this study, 40 samples of abscesses in live animal cases and carcasses of animal slaughterhouses in Mashhad and Binalood were examined. To sample swollen and purulent lymph nodes, a sample of about 1 cc was collected from the swollen glands by a sample syringe and the sample containing the sample was transferred to the laboratory along with ice. The collected samples were transferred to BHI culture medium and after confirmation by tests such as hot staining, catalase test and detection from bacterial strain, discing was performed to determine the resistance and sensitivity of the isolates by Kirby Baer method. Examination of the sensitivity and resistance of the studied isolates showed that the highest resistance of the isolates to Doxycycline antibiotics (72/5%) and the lowest resistance to Trimethoprim/Sulfamethoxazole antibiotics (17.5%). Also, in the study of the sensitivity of isolates, the highest sensitivity of isolates to antibiotics was enrofloxacin and the lowest was Chloramphenicol. The agar diffusion disc method can be used as a primary and primary screening method to determine the level of resistance and sensitivity, so a genotypic method can be used to accurately assess the resistance of the isolates.

Bovine viral diarrhea (BVD) is an endemic disease in most parts of the world, and major damage of the disease, including reduces milk production, reproductive problems such as abortion, weight loss, growth loss and decreasing of immune system. High prevalence and rapid transmission among animals are characteristics of this disease that the importance of control of disease has increased. Conditions of farms, geographical location of regions and other risk factors, including the presence of other viral and bacterial diseases and management of reproduction and milk production influence on the prevalence of BVD in the cows. Many studies have reported the prevalence of this disease in different parts of Iran. The highest prevalence of this disease has been reported in Mashhad, Alborz and Kerman city, respectively. The average prevalence of BVD in Iran is 47.37% according to studies reported until the end of 1399 year. Results of studies indicate that the prevalence of this disease is higher throughout the Iran. Therefore importance of control and prevention of this disease is high in Iran.