Iranian Journal of Veterinary Research
Volume:22 Issue: 3, Summer 2021

Shiga-toxin-producing Escherichia coli (STEC) is an important food-borne pathogen causing human diseases with severe symptoms. Although the O157 serotype has been mostly isolated from human specimens, the increasing incidence rates of non-O157 serogroups have attracted special attention in recent years. Evaluation of the epidemiology and identification of different characteristics of STEC isolates from raw beef, chicken meat, and vegetable samples in Shiraz, Southwest Iran. Two hundred beef and chicken meat samples from different parts of carcasses and four hundred vegetable samples (carrots, lettuce, cucumber, and leafy greens) were randomly taken; STEC were isolated and confirmed using standard microbiological methods. Antimicrobial susceptibility testing (AST) was performed using the Kirby-Bauer disc diffusion method. Polymerase chain reaction (PCR) was used for the identification of O-serogroups, virulence, and antibiotic resistance genes. 52% of beef, 8% of chicken, and 7.2% of vegetable samples were STEC-positive. Further, the highest frequency of virulence factors belonged to the co-existence of stx1 and stx2. O157 serogroup was only detected in beef (3.8%) and lettuce (16.6%) isolates, while the rates of the non-O157 serogroups were relatively high (up to 44.2%). The highest resistance rate in the STEC isolates of different samples belonged to nalidixic acid (62.5%), tetracycline (55.7%), and ampicillin (48%). Paying more attention to non-O157 serogroups in future studies is recommended due to the relatively high prevalence of theses STEC serogroups in our study. Besides, the high level of resistance to some antibiotics observed in this study needs to be addressed.

Corneal lesions are considered among important ophthalmic conditions in avian patients. Short-term outcome of using anti-inflammatory agents in corneal lesions of birds are not well-described. The study evaluates effects of different anti-inflammatory agents on healing of alkali burn-induced corneal lesions in layer hens as an avian model. Adult layers were randomly allocated into 7 groups (n=15) as follows: 1. Negative (normal) control (NC), and 2. Positive control (PC) with an experimentally induced-corneal lesion, 3-7. Birds with corneal lesions that were treated with dexamethasone, fluorometholone, prednisolone, ketorolac, or diclofenac eye-drops every 6 hours (QID) for 5 consecutive days. At the end of the experiment, proper healing was observed in PC group based on lesion area, while treated groups showed statistically larger lesion sizes as compared to PC birds (p <0.05). Although no significant difference was observed among groups, birds treated with ketorolac, diclofenac or fluorometholone had higher histopathological scores for most of the assayed parameters than other groups. Levels of tumor necrosis factor-α (TNF-α) and vascular endothelial growth factor (VEGF) in corneal tissue of different groups were statistically the same. The mRNA expression of matrix metalloproteinase-9 (MMP-9) was increased 2.5 folds in PC group as compared to NC birds. However, birds treated with anti-inflammatory agents showed no detectable expression of MMP-9 mRNA. Five days of topical administration of non-steroidal anti-inflammatory agents (NSAIDs) or glucocorticoids (GCs) is associated with suppression of MMP-9 mRNA expression in corneal tissue and detrimental effects on wound healing in layers with alkali burn-induced corneal ulcers.

Citral (C10H16O) is the main ingredient of Cymbopogon citratus (lemongrass oil) and can reduce the side effects of oxidative stress. Diabetes caused by insulin deficiency induces oxidative stress in the liver. This study aimed to investigate the ameliorative effects of citral on selected oxidative parameters and the gene expression of paraoxonase 1 (PON1) and endothelial nitric oxide synthase (eNOS) in a rat model of streptozotocin (STZ)-induced diabetes mellitus. Forty rats were divided into four groups at random: control (C), control citral (CC), and two STZ-induced diabetic groups (diabetic (D) and citral diabetic (CD)). After diabetes confirmation (day 7), gavage treatment with citral (300 mg/kg body weight (BW)) was started in the CD and CC groups and continued for two weeks. On day 21 of the study, following treatment with citral for 14 days, the serum levels of total antioxidant capacity (TAC), and PON1 in the CD group were significantly increased compared to those in the D group (P<0.05). While treatment with citral caused a significant decrease in the Malondialdehyde (MDA), and eNOS in the CD group compared to those of the D group (P<0.001). The expression rate of liver PON1 gene was considerably upregulated in the CD group compared to that in the D group (P<0.001); while the opposite was observed for eNOS gene expression. However, there was no significant difference between the CC and C groups in terms of all examined parameters (P>0.05). This study showed positive effects of citral on serum antioxidant status and liver gene expression of PON1 and eNOS in diabetic rats.

There is evidence representing the possible relationship between avian pathogenic Escherichia coli (APEC) and other extraintestinal pathogenic E. coli (ExPEC) strains such as human uropathogenic isolates. ‏‏The present study was conducted to evaluate virulence and phylogenetic relationship between a total of 70 APEC and UPEC isolates (35 APEC and 35 UPEC isolates) obtained from the north of Iran which is one of the core areas of the country’s poultry industry. Polymerase chain reaction (PCR) and random amplified polymorphism DNA (RAPD) analyses were conducted using specific primers, and data was analyzed using BioNumerics and SPSS softwares. The most prevalent gene was fliC (70.6%) followed by fimH (67.1%), but APEC and UPEC isolates showed inordinate and obvious differences in the presence of some virulence genes such as fliC, hlyD, and sfa1 and predominant phylogenetic groups in DNA fingerprinting methods. The results showed obvious differences existed between isolates of APEC and UPEC in terms of phylogenetics and pattern of virulence gene; however, despite having virulence genes such as papC, ibeA, and iss, APEC isolates can have a high potential for causing disease in humans and may generate dangerous outbreaks in communities with low levels of hygiene in public and the poultry industry.

Deoxyuracil triphosphate nucleotide (dUTP) pyrophosphatase (dUTPase, DU) is an enzyme of caprine arthritis-encephalitis virus (CAEV) that minimizes incorporation of dUTP into the DNA. Caprine arthritis-encephalitis virus relies partly on its ability to escape from innate immunity to cause persistent infections. Interferon β (IFN-β) is an important marker for evaluating the innate immune system, and it has a broad spectrum of antiviral activity. This study was conducted to investigate the details of the IFN-β response to CAEV infection. The expression of IFN-β and the proliferation of Sendai virus (SeV) and vesicular stomatitis virus (VSV) were determined by real-time quantitative polymerase chain reaction (qPCR). The effect of DU on the IFN signaling pathway was evaluated using luciferase reporter assays. In our study, the expression of IFN-β was significantly inhibited and the proliferation of SeV and VSV was promoted in cells overexpressing CAEV-DU. DU affected interferon stimulated response element (ISRE) and IFN-β promoter activities induced by RIG-I/MDA5/MAVS/TBK1 pathway, while did not affect them induced by interferon regulatory factor 3 (IRF3-5D). DU protein downregulated the production of IFN-β by inhibiting the activity of the signal transduction molecules upstream of IRF3, thereby, helping CAEV escape innate immunity. Findings of this work provide an evidence to understand the persistent infection and multiple system inflammation of CAEV.

Avian metapneumovirus (aMPV) infection has significant economic impacts on the poultry industry all around the world. The aim of this study is molecular investigations of different types of aMPV in broiler farms in different provinces of Iran from 2016 to 2018. Tracheal and oropharyngeal swabs were collected from two hundred broiler chickens with respiratory signs in ten provinces of Iran, including Kurdistan, West Azerbaijan, Semnan, Esfahan, Sistan and Baluchistan, Qazvin, Khuzestan, Fars, Gilan, and Khorasan Razavi from February 2016 to December 2018. After RNA extraction, the presence of aMPV was confirmed using N gene special primers. Then, subtype-specific primers were utilized to differentiate the specific subtype. All positive samples were sequenced. As a general trend, the percentage of aMPV positive chickens increased gradually over time. All samples were clustered together and placed in the subtype B aMPV group. Although 2 samples from 2016 and 2 samples from 2018 were placed in a separate branch, most of the current study samples of 2016, 2017, and 2018 revealed six segregated sub-branches, and they were placed close to other isolates of 2011 and 2013 from Iran. The current field study indicated the presence of aMPV in a considerable number of areas in Iran. Thus, the role of this virus in broiler respiratory complex should not be neglected.

Feline mammary gland tumors (FMGTs) are the third most diagnosed tumors in cats. Feline mammary gland tumors have aggressive biological behavior and poor response to both surgical and medical treatments, thus, new therapeutic approaches are essential to improve. Curcumin (CUR) is a polyphenol component exhibiting anti-cancer effects and induces apoptosis through different mechanisms especially in human breast cancer. However, there is no study investigating the effects of CUR on FMGTs. The aim of this study was to determine the anti-proliferative and apoptotic effects of CUR on primary cell lines from FMGT tissue samples of two cases classified as carcinoma-simple, tubular type (grade III). The cytotoxic effect of CUR was determined by water-soluble tetrazolium salt-1 (WST-1) assay. Annexin V, cell cycle, and acridine orange (AO) analyses were performed to determine the apoptotic effect of CUR. Our results showed that CUR had an anti-proliferative and apoptotic effect through induction of apoptosis and cell cycle arrest (G0/G1) on FMGT cells. Therefore, this is the first study that shows the effects of CUR on FMGTs. However, further molecular studies are required to compare the effects of CUR on different histopathological phenotypes and to determine the further molecular mechanisms including the potential apoptotic and cellular pathways affected by CUR.

Brucellosis is an important zoonotic disease in Iran. There are several reservoirs for this disease in nature. There is little information in this regard in Iran.

The present study investigated the prevalence and diversity of Brucella species in ovine reticuloendothelial organs including liver, spleen, intestine (mesenteric lymph nodes), and lung. This help to address the ability of the reservoir species in disease transmission to other animals through these organs.

A total of 200 ovine visceral organs including 44 intestines, 51 lungs, 52 spleens, and 52 livers were collected. The presence of different Brucella species was studied using the polymerase chain reaction (PCR).

The results demonstrated the prevalence of Brucella species in 56 (28.4%) samples. In addition, liver and intestine were the most and the least infected organs, respectively. In general, 48 out of 56 positive samples were infected with Brucella abortus, while 10 samples were infected with Brucella melitensis.

Eventually, the results approved the possible presence of B. abortus among domestic animals, especially sheep and cattle, and highlighted the role of sheep as reservoir hosts for its potential transfer to cattle.

Supplementing the semen extender with various antioxidants can increase the quality of semen.

The aim of the present study was to investigate the addition of pyridoxine (vitamin B6), a phenolic compound with antioxidant properties, to soybean lecithin extender on motility and quality indices of goat sperm after freezing-thawing process.

Semen was collected at weekly intervals from four Mahabadi goats, mixed, and was divided into 7 subsamples. They were then diluted with the basal extender supplemented with 0, 2, 4, 6, 8, 10, and 12 mM pyridoxine. Following freeze-thawing process, quality parameters such as sperm motility characteristics, viability, plasma membrane integrity, and malondialdehyde content were determined.

The results showed that pyridoxine at the level of 6 mM caused the highest total motility rate (P<0.05). Progressive sperm motility was highest at the 4, 6, and 8 mM pyridoxine (P<0.05). Although the control group showed the least progressive motility, it was not statistically significantly different from the 12 mM level. Among the pyridoxine levels, the 6 mM level recorded the best performance in term of plasma membrane integrity, sperm viability, and decreasing malondialdehyde concentration compared to the control group (P<0.05).

The findings indicated that soybean lecithin extender supplemented with 6 mM pyridoxine can improve motility and quality parameters such as viability, plasma membrane integrity, and reduce oxidative stress of goat sperm after thawing.

Microbes become unresponsive to the drugs used to treat infections due to their ability to acquire antimicrobial resistance.

The present research aimed to study the patterns of phenotypic and genotypic antimicrobial resistance in Staphylococcus spp. isolated from goat milk.

A total of 200 milk samples were collected to isolate Staphylococcus spp. from mastitic and healthy goats from Punjab state, India. The isolates were then identified biochemically and molecularly (polymerase chain reaction (PCR)). An antibiotic sensitivity test was conducted using 15 different antibiotics. Molecular detection of antibiotic resistance genes was done using PCR. Chi-square test was done to study the association between genotypic and phenotypic resistance patterns among the isolates.

A total of 47 Staphylococcus spp. were isolated of which 33 and 14 isolates were respectively coagulase positive and negative. The isolates phenotypically showed the highest resistance to Penicillin G (P) (91.4%). Methicillin resistant Staphylococcus aureus (MRSA) was found 56.25%. Amongst the antibiotic resistance genes, tetK (87.23%) was the most prevalent isolated gene followed by blaZ (85.10%), mecA (48.93%), and tetM (14.89%). Statistical analysis revealed that the genotypic and phenotypic resistance patterns were significantly associated with penicillin and methicillin (MET) resistances.

The high prevalence of antibiotic-resistant Staphylococcus spp., especially MRSA, in goat milk is of concern and needs to be addressed in this area.

Fowl adenoviruses (FAdVs) are responsible for a variety of clinical symptoms, with an increasing significance in the poultry industry throughout the world. Typical diseases caused by FAdVs include inclusion body hepatitis (IBH), hepatitis-hydropericardium syndrome (HHS), gizzard erosion (GE), respiratory disease, and hemorrhage in muscles and organs.

During 2020, broiler chickens from the north of Iran showed ecchymotic and petechial hemorrhages in thigh and breast muscles at the slaughterhouse. Hemorrhages were observed in 10% to 60% (with an average of 20-30%) of chicks per flock. To find out the etiology of these lesions, the present study was conducted.

Different environmental factors were investigated, and FAdV, infectious bursal disease virus (IBDV), and chicken infectious anemia virus (CIAV) were detected using molecular assays.

Among the viruses tested, FAdV was detected by polymerase chain reaction (PCR), and sequence analysis clustered the virus into species E, serotype 7.

This is the first report on FAdV-7 existence among poultry in Iran. Effective screening of the chicks at slaughtering age should be performed from the whole country.

Tritrichomonas foetus is recently found to be one of the causes of chronic diarrhea in domestic cats but there is no report of feline intestinal trichomoniasis in Iran.

A 9 months female domestic short-haired cat was referred to our hospital with a history of chronic diarrhea over the past two months, and with an unsuccessful previous antibiotic therapy in another clinic.

Clinical examination revealed 39.8°C rectal temperature. Complete blood count (CBC) showed moderate inflammatory leukogram. By the wet-mount faecal assessment, moving organisms were observed. Rectal scarping dry-mount cytology revealed many inflammatory cells along with huge numbers of trophozoites with typical morphologic characteristics including central axostyle, undulating membrane, flagella, and one laterally located nucleus. Polymerase chain reaction (PCR) was performed and confirmed the diagnosis of T. foetus. After treatment with metronidazole and probiotics, the cat was completely recovered.

This study represents the first case of intestinal trichomoniasis in a cat with chronic diarrhea in Iran.