Iranian Journal of Veterinary Research
Volume:23 Issue: 1, Winter 2022

Infected poultry is one of the most important reservoirs of Salmonella.

The investigation presented here was conducted to examine the occurrence of Salmonella in fecal samples among selected flocks of backyard poultry in Bosnia and Herzegovina (B&H).

Isolation and identification of Salmonella was performed in accordance with BAS EN ISO 6579/AMD 1:2007. When genus Salmonella was confirmed, the determination of the antigenic formula of Salmonella isolates was performed in accordance with BAS CEN ISO/TR 6579-3:2015. After that, Salmonella serotypes were subjected to antibiotic susceptibility testing using EUVSEC sensititre microtiter plates impregnated with different concentrations of antibiotics. At the end, real-time PCR was used to detect extended spectrum β-lactamases (ESBL) and carbapeneamase encoding genes (blaTEM, blaSHV, blaCTX-M, blaCMY, blaKPC, blaNDM, blaOXA-48, blaVIM and blaGES).

Salmonella spp. was detected in pooled feces from four backyards, housed by chickens only. Three isolates were confirmed by slide agglutination as serotype Enteritidis and one as serotype Typhimurium. Antibiotic susceptibility testing by microdilution did not reveal phenotypical resistance among these four isolates. Real-time PCR used to detect ESBL and carbapeneamase encoding genes revealed the blaTEM gene in one S. Enteritidis isolate.

Data presented in this study provide further evidence on the circulation of different Salmonella serotypes in backyard poultry in B&H. These findings emphasize the potential role of backyard poultry in the epidemiology of salmonellosis and the risks it poses for keepers, consumers, and general public health.

Leptospirosis is considered to be an economically important disease in bovine. The disease burden is not appropriately monitored due to cumbersome serological tests that could be performed only in established laboratories. This warrants the development of a field level rapid diagnostic test.

The study aimed to develop a lateral flow assay (LFA)-based pen-side diagnostic test to detect antibodies to Leptospira.

LFA strip was prepared with the heat extracted antigen from L. interrogans serovar Pomona. To assess the performance of the developed LFA, a total of 300 bovine serum samples with their clinical histories were used and the initial screening for Leptospira antibodies was performed by the standard microscopic agglutination test (MAT). The sensitivity, specificity, and agreement (kappa value) were calculated between developed LFA and MAT. The stability of LFA was evaluated on days 30, 60, 90, and 120.

Out of 300 samples tested, 225 were positive, and 75 were negative on MAT and 208 were positive, and 92 were negative on LFA. The developed LFA had a sensitivity of 90.7% and a specificity of 94.7%. The results of the assay were substantially in agreement with MAT, with a kappa value of 0.79. The LFA strips were stable for 120 days at 4°C.

A Lateral flow assay-based rapid pen-side test was developed and its utility to diagnose bovine leptospirosis was evaluated.

Bovine tuberculosis (BTB) is a disease with high economic relevance.

This study aimed to determine a fast alert surveillance system for bTB before the outbreak in the epidemic region of Iran.

This cross-sectional study was conducted using the Auto-Regressive Integrated Moving Average (ARIMA) model for monthly bTB detections (reactors). These reactor cases result from the positive Tuberculin Purified Protein Derivative (PPD) test on cattle farms for the period between April 2007 and March 2019 in Razavi Khorasan province. Autocorrelation functions (ACF) and partial autocorrelation functions (PACF) plots were used to determine model parameters. The Akaike Information Criteria (AIC) were employed to select the best-fitted model. The root mean square error (RMSE) was applied for the evaluation of the models. Then, the best-fitted model was hired to predict the cases for 12 oncoming months. The data were analysed by STATA (ver. 14) software with a significant level at P≤0.05.

ARIMA (3, 0, 3) 12 was introduced as a recommended fitted model according to white noise residual test (Q=22.87 and P=0.98), lower AIC (541.85), and more precise model RMSE (1.50). However, the forecast values were more than the observed values.

The application and interpretation of ARIMA models are straightforward, and may be used as immediate tools for monitoring systems. However, we proposed an Auto-Regressive Integrated Moving Average with Exogenous Input (ARIMAX) model with some measurable exotic factors such as economic fluctuations, climate changes, and pulmonary tuberculosis to introduce a more precise and accurate model for the fast alert surveillance system.

Infectious bronchitis virus (IBV) causes severe economic losses worldwide. IBV has a broad tissue distribution with different viral loads in different tissues. Additionally, IBV can induce apoptosis in infected cells.

The present study aimed to evaluate the role of the genetic background of chickens in viral load and the expression level of apoptotic genes in different tissues of two hybrids of commercial broiler chickens (Ross 308 and Cobb 500) challenged with IBV.

Chickens at 21 days of age were nasally challenged with 200 μL of allantoic fluid containing 104 EID50/ml of Iranian variant-2-like IBV (IS/1494). The expression level of apoptotic genes (Fas, FasL, Bax, and Bcl-2) in the tracheal and renal tissues and the amount of viral load in the tracheal, renal, and cloacal swab samples were investigated two, five, and seven days after IBV infection by RT-qPCR assay.

The amount of viral load and apoptotic the expression level of apoptotic genes in the tracheal (two and five days after infection) and renal samples (seven days after infection) were significantly higher in the Ross challenged group than in the Cobb challenged group. Furthermore, no difference was observed in the cloaca viral load on sampling days.

To our knowledge, this is the first report that evaluated the role of the chickens’ genetic background in the amount of viral load and the expression level of apoptotic genes against IBV. Further studies are needed to investigate the pathogenic characteristics of IBV in Ross 308 and Cobb 500 chickens.

Thermophilic Campylobacters are found in the digestive tract of wild and domestic poultry and can be transmitted to humans following their fecal discharges.

This study aimed to isolate thermophilic Campylobacter by culture from cloacal swabs of geese, commonly breeding in Kars region, and to identify the isolates by PCR and mass spectrometry. Antibiotics susceptibility and resistance genes of the isolates were also analysed.

The study included 400 cloacal swab samples of clinically healthy geese. The samples were cultured on mCCDA medium following the pre-enrichment in Preston broth. Identification of the isolates was performed by phenotypic methods, PCR, and MALDI-TOF MS. Antibiotic susceptibility and resistance genes of the isolates were analysed with the disc diffusion method and PCR, respectively.

Thermophilic Campylobacter spp. were isolated from 157 (39.3%) samples. 151 (96.2%) isolates were identified Campylobacter jejuni and 6 (3.8%) Campylobacter coli by the phenotypic tests and PCR. Among 125 isolates analysed by MALDI-TOF MS, 119 (95.2%) were identified C. jejuni and 6 (4.8%) C. coli. The isolates’ resistance to ampicillin, tetracycline, ciprofloxacin, gentamicin, and azithromycin were found 33.8%, 41.4%, 75.2%, 12.1%, and 7.6%, respectively. The distributions of blaOXA61, tetO, gyrA, and aphA-3 genes were 3.2%, 90.8%, 50.8%, and 52.7%, respectively.

Since geese are raised in pastures in the Kars region, protecting and not polluting the existing natural environment and preventing their contact with wild birds will prevent the spread of these microorganisms.

Ornithobacterium rhinotracheale (ORT) is one of the most important pathogenic bacteria which cause significant economic losses in poultry breeder countries every year.

The present study was conducted to isolate and investigate the ORT isolates’ biochemical, antibiotic resistance, and genotypic characteristics of in industrial poultry flocks with respiratory signs in northern Iran.

After sampling from 60 different flocks and cultivation of the samples on a selective medium, suspected colonies were subjected to biochemical and molecular identification of ORT. Then, confirmed isolates were aimed to antibiotic resistance assay, hemagglutination test, detection of pOR1 plasmid, and DNA fingerprinting to survey the variability of the isolates.

A total of 13 isolates, including seven isolates from broiler flocks (19.44%) and six isolates from broiler breeder flocks (25%) were obtained. Almost all isolates showed similar results in terms of basically important biochemical tests. The most resistance rates among all ORT isolates were obtained for ampicillin, erythromycin, ceftriaxone, and penicillin (100%). The majority of ORT isolates were susceptible to furazolidone. The pOR1 plasmid was detected in only two isolates, and analysis of the DNA fingerprinting phylogenetic tree showed four specific genotypic clusters.

According to the results, the isolates showed different antibiotic resistance profiles, and most of the strains proved multiresistant. This can indicate the circulation of various multi-drug resistant strains among poultry farms in northern Iran. Isolates from broilers and broiler breeders were grouped into different clusters by genotyping.

Salmonella in chicken, specially, the motile salmonellae, causes the food chain unsafe from farm to table and is considered a significant global threat to public health.

The present study was carried out for molecular detection of Salmonellae in commercial poultry using PCR.

The study was conducted for eight months, from July 2019 to February 2020, and a total of 26 poultry farms, including 15 broiler and 11-layer farms, were visited individually. Pooled faecal samples were obtained from the sheds. A total of 189 necropsy cases were examined for gastrointestinal lesions. Isolation and identification of the organism were done using microbe culture method, and the molecular characterization was performed via PCR targeting invA and ent genes.

The prevalence of salmonellosis in the broiler and layer farms was recorded at 20.0% and 45.4%, respectively, through the traditional gold standard culture method. From 189 necropsy birds, salmonellosis was recorded at 1.58% dead cases. Molecular detection of Salmonella isolates by PCR targeting invA gene was confirmed in 13.33% of the broiler farms and 36.3% of the layer farms. Further detection of Salmonella enteritidis was performed by PCR targeting ent gene by which 11.11% positivity was determined.

This study, focused on the Salmonella prevalence, highlighted the zoonotic importance of the bacterium in the commercial poultry farms, which can subsequently be dispersed into the human food chain causing harmful health effects.

Recent research has shown that chitosan has good moisture-absorbing properties at the micro and nanoscale, and seems to be a good candidate for the production of biodegradable moisture-absorbing films.

The aim of this study was to evaluate the properties and antibacterial activity of starch-based microchitosan (MCH) films impregnated with two essential oils (EOs).

MCH films with varying thicknesses were made from cornstarch (6%), microchitosan (1%), glycerol (2.25%), and/or EOs (2%), and their characteristics, including swelling degree (SD), tensile strength (TS), and elongation at break (EB%), were examined. The film structures were confirmed by X-ray diffraction (XRD), scanning electron microscopy (SEM), and atomic force microscopy (AFM). To determine the antibacterial activity against Escherichia coli and Staphylococcus aureus, two EOs of Shirazi thyme, garlic, and a mixture of them were used in the experimentation.

The EB% and TS had a linear relationship with the thickness of samples and improved by increasing the thickness of films. The XRD pattern showed that the MCH films had an amorphous structure. SEM of the films showed a homogeneous dispersion of MCH in the starch matrix without any porosity. The AFM images showed a simultaneous increase in the thickness of the MCH films and surface roughness. The film was able to absorb water up to 15.78 times its weight in 48 h. The inhibition zone of films containing 2% thyme EO was 42.0 mm for S. aureus and 12.3 mm for E. coli (P<0.05).

MCH film containing Shirazi thyme can be described as a moisture-absorbing antibacterial pad and is a new idea for active food packaging to increase the shelf life of foods with fully degradable properties.

In mammalian females, the uterine tissue is highly responsive to steroid hormones and their antagonists.

In the present study, topographical, histoarchitectural, and gene expression changes in goat endometrium treated with estradiol, progesterone, and mifepristone for 24 h were investigated, in vitro.

Scanning electron microscopy (SEM) was used for surface topographical analysis; WGA and DBA lectins were used for histochemical analysis; and qRT-PCR was done for the quantification of mRNA levels of MKI67 (marker of proliferation Ki67), ESR1 (estrogen receptor), PGR (progesterone receptor), CASP3 (caspase 3), and PDGFR-β (platelet derived growth factor receptor-β).

Few topographical alterations were observed in endometrial glands and the presence of scattered mucoid granules. A significant decline in WGA staining was reported only in the progesterone group. However, DBA binding was highest in the progesterone group and lowest in the mifepristone group. The expression of MKI67 gene declined to 79% in the mifepristone group, while in the estradiol and progesterone groups it elevated to 153% and 41%, respectively, than control; a similar trend was observed for PDGFR-β. The mRNA abundance for ESR1 declined to 59% in the progesterone group and 10% in the mifepristone group. However, a 100% increase occurred in the estradiol group. PGR expression followed the same trend as that of ESR1. CASP3 declined in the estradiol (50%) and progesterone (37%) group, but it showed a 67% increase in the mifepristone group.

We concluded that the caprine uterus undergoes dramatic alteration in structure and functions in response to different kinds of steroidal environments.

Heilongjiang province is the main cattle-producing area in China, and molecular epidemiological studies of bovine viral diarrhea viruses (BVDV) in cattle have not been performed in the province.

The objective of this research was to determine the genetic and clinical characteristics of BVDV in cattle.

Fifty-three BVDV-positive clinical samples were collected from 22 cattle farms in Heilongjiang, and the 5´-untranslated region (5´-UTR) was used to carry out a phylogenetic analysis of the viruses.

The similarity of the 5´-UTR sequences among these BVDVs was 84.2%-100%, and the phylogenetic analysis showed that all viruses belong to the BVDV-1 species, which is classified into five subtypes: BVDV-1b (47.17%, n=25), 1c (15.09%, n=8), 1d (16.98%, n=9), 1 m (3.77%, n=2), and 1o (16.98%, n=9). The statistical results showed that the BVDV-1b subtype had a positive correlation with gastrointestinal disease (P<0.05; 95% CI: 1.19 to 3.34). There were up to three or four BVDV-1 subtypes in some dairy cattle farms, but farms with a single subtype were prevalent (5/10).

BVDV-1b is predominant in cattle herds of Heilongjiang province, China, and shows a positive correlation with gastrointestinal disease. BVDV-1o was found for the first time in Chinese cattle, which increased the complex distribution of BVDV-1 subtypes in cattle herds of China.

Avian reovirus (ARV) is a major poultry pathogen associated with arthritis, malabsorption, and enteric diseases in chickens. In recent years, emerging ARV strains have become a growing concern causing significant economic losses in broiler chickens around the world. This report focuses on the isolation of ARV from the clinical occurrence of ARV-associated diseases in commercial broiler chickens in Iran and the genotypic characterization of the selected isolates.

In 2018, two distinct clinical diseases, suggestive of malabsorption syndrome (MAS) and viral arthritis, were noticed in commercial broiler chickens in the north of Iran. Laboratory investigations were carried out following necropsy, documentation of the gross lesions, and sampling of the affected tissues for histopathology and virology. Molecular diagnosis and characterization of ARV were performed targeting Sigma C (σC) gene sequences of the virus.

Two variant ARV strains were isolated from tendon and gizzard of broilers with clinical viral arthritis and MAS, respectively. Phylogenetic analysis of the ARV σC gene sequences revealed that field isolates were clustered in genotypes 2 and 4 (which were distinct from previous Iranian field ARV strains) with relatively low sequence identity (59.2% and 49.1%) to the classical vaccine strains (S1133 and 1733) in genotype 1.

This report, for the first time, represents new emerging ARV variants associated with clinical events in Iran, providing insights on the diversity of endemic ARV field isolates, and urges the need for national-wide surveillance of ARV.