فصلنامه پاتوبیولوژی مقایسه ای
سال شانزدهم شماره 65 (پاییز 1398)

Putrefactionin causes unpleasant odors, undesirable changes in taste, color and texture, and reduced nutritional value. at usage of active coating that contain antimicrobial agents ̨ many factors should be considerable. Most of these factors depend on the chemical nature of the antimicrobial agent, the type of food and the target microorganism. In this study, investigated̨ the chemical and microbial properties of Rainbow trout fish that Coated with Curcumin Nanomulsion. The prepared samples are divided into 4 groups, which include control treatment, nanoemulsion containing 1, 3 and 5% curcumin. In order to investigate the effect of treatments on the chemical properties ̨ pH and free fatty acid and total volatile basic nitrogen, were measured. Microbial characteristics were evaluated through microbial total count, fecal coliforms and coagulase-positive Staphylococcus aureus. Also for sensory evaluation by panelists ̨odor, texture, color and fish general acceptance were evaluated. The results of this study showed that by using nanoemulsion coating that include 5% curcumin, the shelf life of the fish could be increased for 10 days, with favorable chemical and microbial properties.

Klebsiella pneumoniae is a gram-negative intestinal bacterium that causes nosocomial infections. The aim of this study was to evaluate the genotype of calcitonin-resistant genes (mcr-pmr) in Klebsiella pneumoniae isolated from raw milk by Multiplex-PCR. Samples were collected from 220 raw milk storage tanks in Tehran milk storage centers in 1977. Klebsiella pneumoniae strains were identified using standard biochemical and microbiological tests. DNA extraction was performed according to the National Center for Genetic and Biological Resources of Iran (MBK0041) kit. After PCR test in thermocycler apparatus to determine the presence of mcr and pmr genes, the samples were transferred onto 1% agarose gel and stained with ethidium bromide and then analyzed in dock gel apparatus. In this study, 60 genotypes of mcr and pmr genotypes were studied in 60 isolates of K. pneumoniae. Meanwhile, the Mcr gene was reported at a frequency of 11, (18.3%) and the Pmr gene was reported at a frequency of 7 (11.6). The trace of the two genes was investigated by Multiplex-PCR method. This seems to be the first study of two Mcr, Pmr genes, in Iran of milk samples isolated from milk storage tanks in industrial farms from Klebsiella pneumoniae and two of these genes were identified as the main marker.

Purslane (Portulaca oleracea L.) is a widespread weed. Purslane has been used in folk medicine in many countries as a diuretic, febrifuge, antiseptic, antispasmodic. The present study was performed to assess the possible protective roles of purslane ethanolic extract on cadmium-induced testicular damage in adult Wistar rats. The 60 rats were randomly divided into 10 groups: normal control, purslane extract (50, 100, 200 and 400 mg/kg, intragastrically, daily), testicular damage control rats (cadmium chloride 3 mg/kg, intragastrically, daily), purslane extract (50, 100, 200 and 400 mg/kg, intragastrically, daily), together with cadmium chloride. After 28 days of treatment, the animals sacrificed and the testes were removed. Antioxidant enzyme status and lipid peroxidation levels in testicular tissue were determined. Our results showed that cadmium chloride significantly decreased glutathione peroxidase, superoxide dismutase, catalase activities, whereas increased malondialdehyde levels in testis. Administration of purslane extract significantly increased glutathione peroxidase, superoxide dismutase, catalase activities, whereas decreased malondialdehyde levels in testis. Our study demonstrated that purslane extract proffers a measure of protection against cadmium-induced antioxidant enzymes in rats.

The hydroxy-carboxylic acid receptor 2 (HCA2 receptor) is the target of niacin. In the present study we describe the expression pattern of these receptors in cells of different parts of alimentary canal (from esophagus to rectum) of rats by immunohistochemical method. Six adult male Wistar rats were euthanized under deep anesthesia. Five μm-paraffin transverse sections were made from esophagus, stomach duodenum, jejunum, ileum, cecum, colons and rectum. The primary antibody for immunohistochemical staining was rabbit polyclonal GPR109A antibody (1:300, incubation for one night at 4°C) which reacts with rat HCA2 receptor. Secondary antibody was HRP-conjugated. We observed weak immunoreactivity in epithelial cells of esophagus and non-glandular stomach, strong immunoreactivity of HCA2 receptors in epithelial cells of duodenum, jejunum, ileum and jejunal muscular layer. Moreover, colon showed weak and rectum showed no immunoreactivity. Immunoreactivity was strong in base of caecum. In conclusion, HCA2 receptor proteins are abundantly present in intestinal epithelium and base of caecum of rats which make them a proper laboratory animal for future studies on these receptors in gastrointestinal tract.

Clostridium perfringens is cause of different disease such as enterotoxaemia or overeating or pulpy kidney. This disease occurs with changes in diet, bacterial proliferation and high levels of toxin production. So the detection of toxin in the intestinal tract is used to diagnose of this disease. Timely vaccination is important in order to prevent of enterotoxaemia. The purpose of this study was to select the most toxigenic isolate of Clostridium perfringens type C in order to vaccine production. In this research, 21 isolates of Clostridium perfringens type C were subjected to microbiological and biochemical tests, then samples that were identified by routine bacteriological method were confirmed using PCR. Finally, the most toxigenic isolate was selected by MLD and enterotoxaemia tetravalent anaculture vaccine were prepared from this strain and vaccine strain. The experimental vaccines were incubated for 45 days at refrigerator then potency test were done of them. The results of this study showed that the amount of beta toxin of isolated in Razi Institute is four times weaker than the vaccine strain.

Infectious bronchitis is one of the major problems in the poultry industry in the world. Molecular and epidemiological studies, as well as continuous identification of genetic variants among common viruses in farms, play an important role in controlling, preventing and designing effective vaccines against disease. In the current study, chicken flocks with suspected infections bronchitis virus (IBV) were examined in Mazandaran province. Tracheal swab specimens were collected from 28 broiler chickens with respiratory symptoms in northern Iran in autumn and winter of 1396. Mortality rates of 15 to 25 percent were reported in studied flocks. Polymerase Chain Reaction (PCR) was used to amplify the virus replicase gene using specific primers. The reference strain was the H120 bronchitis vaccine. Direct sequencing method was used to identify wild strains from vaccine strains. In the preliminary test, 82% (23/28) of the suspected farms has shown the presence of IBV. Using the sequencing analysis, 5 wild strains were detected in the infected flocks (19 farms), indicating a high diversity in the population under study. The results of this study showed that emerged of new strains of infectious bronchitis virus in broiler flocks in Mazandaran province could be related to breeding conditions such as high density and repeated vaccination and different type of vaccines.

Candida albicans is one of the most common human and animal opportunistic yeasts and causes a wide range of diseases in immunocompromised individuals. Among the most important virulence factors in this yeast are the protease secreting enzymes that play an important role in pathogenesis and invasion. Failure to treat patients infected by Candida albicans infections, with conventional antifungal drugs has led to an inevitable research on new antifungal agents. In this regard, the protease activity of Candida albicans isolates in the presence of propolis extract was investigated in this research. The specimens were isolated from oral (15); nail (8) and vaginal (15) lesions. Protease activity was initially calculated in all isolates, and then the minimum inhibitory concentration of propolis extract obtained in the previous study was used to evaluate the protease activity in the treatment group. Results showed that the mean of minimum inhibitory concentrations and minimum fungicidal concentrations of propolis for all the isolates were 360.6 and 1250.1 μg / ml, respectively. The mean of protease activity in nail, vaginal and oral groups was 0.34±0.06, 0.02±0.03 and 0.35±0.06, respectively. Protease activity of all groups after treatment with propolis decreased significantly compared to control group (P <0.0001). Due to the property of propolis in reducing protease activity in isolates,