Iranian Journal of Veterinary Research
Volume:21 Issue: 4, Autumn 2020

Theileria annulata is a tick-borne apicomplexan parasite that affects bovine and causes severe economic losses.

Our study aimed to determine the molecular prevalence of T. annulata infection in asymptomatic carrier cattle in Odisha, India, to study the association of potential risk factors with theileriosis, and to investigate the effect of the parasite infection on hematological parameters in naturally affected animals.

A total of 226 cattle blood samples were collected from seven districts of Odisha, India. Molecular diagnoses of tropical theileriosis by polymerase chain reaction (PCR), cloning, sequencing, and phylogenetic analysis of isolated parasites were performed. Potential risk factors were investigated by univariable and multivariable logistic regression statistical analysis. Hematological parameters were compared between positive and negative animals.

All animals included in our study were clinically normal, however, 54.86% (124/226) of examined animals were positive by PCR for T. annulata. The multivariable logistic regression showed that contact with other cattle from different herds during grazing (P<0.0001; OR: 12.75; 95% CI: 5.21-31.21), previous history of clinical signs (P=0.002; OR: 3.31; 95% CI: 1.53-6.31), and frequency of a ectoparasiticides application pre year (P<0.0001; OR: 9.22; 95% CI: 3.03-28.09) were the potential risk factors for the occurrence of tropical theileriosis. Nucleotide sequence identity data demonstrated that T. annulata strain (MN818858) Odisha shared homology of 99.6%, 99.49%, and 99.36% with Uttar Pradesh, India (MF346035), Bahrain (AF214797), and Hyderabad, India (MK034702), respectively.

This is the first study to gain insight into the molecular epidemiology, risk factors, phylogeny, and hematological analysis of asymptomatic T. annulata infected cattle from India.

Pulsed wave (PW) Doppler echocardiography provides a convenient and noninvasive tool for measuring cardiac output (CO) alternations after the administration of sedative drugs, but this is not a usual method for camelids.

The aim of the present study was to investigate the changes of the left and right ventricular outflow tracts (LVOT and RVOT), CO, and systolic time intervals following the intravenous (IV) injection of medetomidine (M) and xylazine (X) using PW Doppler echocardiography.

Twenty apparently healthy immature male one-humped camels (Camelus dromedarious) were selected and divided into four groups (five animals per group). Medetomidine and X were injected to the left jugular vein at two different doses of 10 and 20 μg/kg, and 0.2 and 0.4 mg/kg, respectively. Effects on echocardiographic parameters were assessed at 4 intervals: before, 3, 60, and 120 min after drug administrations.

Velocity time integrity (VTI), maximum/mean flow velocity (Vmax and Vmean) and maximum/mean pressure gradient (PGmax and PGmean) decreased in aortic and pulmonic valves. Left ventricular ejection time (LVET) and LVET + pre ejection period (PEP) decreased and PEP and PEP/LVET increased in all groups except the low dose X group, 3 min after drug administration (P<0.05). The least values of VTI, velocity (V), PG and CO were observed after 60 min in the low dose X group (P<0.05).

A relationship was found between the intensity and the duration of changes in cardiac parameters and both types and dosages of the injected drugs. We concluded that X and M have transient depressor effects on the ventricular outflow tract and CO of healthy camels.

Trastuzumab is an antibody drug used to treat human epidermal growth factor receptor 2 (HER2) overexpressing human metastatic breast cancer. Antibody-dependent cellular cytotoxicity (ADCC) is considered to be the major mechanism of cytotoxicity of the drug. However, its ability to induce an ADCC response in canine peripheral blood mononuclear cells (PBMCs) is not well established.

We aimed to evaluate the ability of trastuzumab in enhancing the cytotoxicity of PBMCs against canine tumor cells.

We used canine tumor cell lines isolated from metastatic mammary gland tumors (CHMm and CIPm) and thyroid adenocarcinoma (CTAC). The binding of trastuzumab to the cells was confirmed using flow cytometry analysis. Peripheral blood mononuclear cells obtained from healthy beagles and lymphokine-activated killer (LAK) cells, generated by interleukin-2 (IL-2) stimulation of PBMCs, were used as effector cells. Standard lactate dehydrogenase (LDH) release assay was used to measure the cytotoxicity of the LAK cells against tumor cell lines in the presence of trastuzumab.

Trastuzumab enhanced the cytotoxicity of PBMCs against CHMm. Moreover, LAK cells killed CHMm synergistically in the presence of trastuzumab. However, the presence of trastuzumab did not produce such a synergistic effect when LAK cells acted against CIPm and CTAC.

We confirmed the ability of trastuzumab to induce an ADCC response in canine PBMCs and determined its synergistic effect with LAK cells. Although the in vitro system in the present study did not show the induction of trastuzumab-mediated ADCC response against all canine tumor cell lines, the results of this study indicate the potential antitumor activity of trastuzumab in canines.

Salmonella is considered as a main cause of community-acquired diarrhea in humans, however, sources of the multi-drug resistant (MDR) strains and their link with the disease are not well known.

This study aimed to investigate the frequency, serogroup diversity, and antimicrobial susceptibility patterns of Salmonella strains in poultry meat and stool samples of patients with community acquired diarrhea in Tehran.

We compared the frequency of non-typhoidal Salmonella serogroups, the similarities of their resistance patterns to 10 antimicrobial compounds, the prevalence of extended spectrum β-lactamase (ESBL) and ampicillinase C (AmpC) genetic determinants, and class 1 and 2 integrons in 100 chicken meat and 400 stool samples of symptomatic patients in Tehran during June 2018 to March 2019.

Salmonella was isolated from 75% and 5.5% of the chicken meats and human stool samples, respectively. The chicken meat isolates mainly belonged to serogroup C (88%, 66/75), while the human stool isolates were mainly related to serogroup D (59.1%, 13/22). The MDR phenotype and the most common rates of resistance to antibiotics, including tetracycline, trimethoprim/sulfamethoxazole (TS) and azithromycin, were detected in 4.5% and 45.3%, 59% and 13.6%, 43% and 9.1%, 42% and 9.1% of the human stool and chicken meat samples, respectively. Carriage of blaCTX, blaSHV, and blaPER genes in the meat isolate with ESBL resistance phenotype and blaACC, blaFOX, and blaCMY-2 among the 7 meat strains with AmpC resistance phenotype was not confirmed using polymerase chain reaction (PCR). High prevalence of class 1 and 2 integrons was characterized and showed a correlation with resistance to TS and chloramphenicol.

These findings showed a lack of association between chicken meats and human isolates due to discrepancy between the characterized serogroups and resistance phenotypes.

Unlike dogs, feline abdominal studies are rare. Note that anatomical estudies in felines are scarce and almost unique using feline cadaver by means of sectional anatomy and computed tomography (CT) or magnetic resonance imaging (MRI).

In this study, a non-pathological vascularization model of feline abdomen was conducted on three adult cats was using anatomical and diagnostic imaging techniques.

A live pet cat and two cat cadavers were used in this study. Cat cadavers were injected with colored latex to show well-differentiated vascular structures and serial sections of cat abdomen were then provided. Computed tomography was performed by injecting an iodinated contrast medium through the cephalic vein of a live cat immediately before scanning. The CT images showed the arterial and venous vascular formations hyper-attenuated with two tomographic windows. The correlation between anatomical sections and their CTs was studied to identify vascular and and visceral structures.

Hyper-attenuated vascular structures with the contrast medium were identified and marked along their path in the series of Dicom images with the Amira program. In this approach, sequentially and semiautomatically, vascular volumetric reconstruction was obtained without visceral formations. With the OsiriX program, volumetric reconstruction was automatic and maintained the fidelity of all visceral and vascular formations.

We conclude that these improved prototypes could be used in veterinary clinics as normal vascular models and as a basis for obtaining future 3D models of vascular anomalies such as portosystemic shunts.

Salmonella is one of the most important enteric pathogenic bacteria that threatened poultry health.

This study aimed to investigate the prevalence and antimicrobial resistance of Salmonella isolates in goose farms.

A total of 244 cloacal swabs were collected from goose farms to detect Salmonella in Northeast China. Antimicrobial susceptibility, and resistance gene distribution of Salmonella isolates were investigated.

Twenty-one Salmonella isolates were identified. Overall prevalence of Salmonella in the present study was 8.6%. Among the Salmonella isolates, the highest resistance frequencies belonged to amoxicillin (AMX) (85.7%), tetracycline (TET) and trimethoprim/sulfamethoxazole (SXT) (81%), followed by chloramphenicol (CHL) (76.2%), florfenicol (FLO) (71.4%), kanamycin (KAN) (47.6%), and gentamycin (GEN) (38.1%). Meanwhile, only 4.8% of the isolates were resistant to ciprofloxacin (CIP) and cefotaxime (CTX). None of the isolates was resistant to cefoperazone (CFP) and colistin B (CLB). Twenty isolates (95%) were simultaneously resistant to at least two antimicrobials. Ten resistance genes were detected among which the blaTEM-1, cmlA, aac(6’)-Ib-cr, sul1, sul2, sul3, and mcr-1.1 were the most prevalent, and presented in all 21 isolates followed by tetB (20/21), qnrB (19/21), and floR (15/21).

Results indicated that Salmonella isolates from goose farms in Northeast China exhibited multi-drug resistance (MDR), harboring multiple antimicrobial resistance genes. Our results will be useful to design prevention and therapeutic strategies against Salmonella infection in goose farms.

Brucellosis is a zoonosis, caused by Brucella spp. which are small aerobic intracellular coccobacilli, localized in the reproductive organs of host animals, causing abortion and sterility. The diagnosis of this zoonosis is based on microbiological, serological or real time-polymerase chain reaction (RT-PCR) laboratory tests. Although the common microbiological and serological based assays have advantages, they are not able to solve the diagnosis problems.

To overcome some of the limitations of present techniques, in this study, we developed an aptamer through whole-cell systematic evolution of Ligands by EXponential enrichment (SELEX) procedures to detect Brucella.

We used mixture of Brucella melitensis and Brucella abortus as the target. In order to prepare the single-stranded DNA (ssDNA) aptamer, the DNA library was amplified with 5´-phosphorylated reverse primer and treated with lambda exonuclease. The SELEX procedure was performed by incubating the ssDNA pool with a bacterial suspension in a binding buffer. The selected procedures were monitored by flow cytometry using FITC-labelled forward primer. Aptamers with the highest binding affinity towards the target and the lowest to other strains were selected.

Two aptamers namely B20 and B21 showed significant binding affinity toward B. melitensis and B. abortus. The dissociation constant (Kd) for aptamers B20 and B21 was 40.179 ± 3.06 pM and 184.396 ± 465 pM, respectively.

The isolated aptamers were able to identify B. melitensis and B. abortus with a remarkable binding efficiency and appropriated Kd in a picoMolar range and therefore can be good candidates in the development of any rapid assay test implanted on routine brucellosis diagnoses.

Cutaneous pythiosis in horses is a chronic ulcerative granulomatous disease caused by the oomycete Pythium insidiosum.

The objective of the present study was to evaluate the response of cutaneous pythiosis in horses to surgical excision and topical dimethyl sulphoxide (DMSO).

Thirty horses were presented clinically with pruritus, fistulae discharging serosanguineous fluid, and output kunkers in different body areas (limb, abdomen, neck, and face). The clinical diagnosis was confirmed by isolation of the causative agent and histopathology. All animals were treated by surgical excision alone, or surgical excision followed by topical DMSO. The healing process was monitored every week macroscopically to evaluate the response to treatment until complete recovery.

The existence of Pythium insidiosum was confirmed in all cases. Histologically, affected horses were characterized by granulation tissue with abundant eosinophils. The size of wounds and the clinical features of pythiosis lesions decreased more after surgical debridement with DMSO application than surgical excision alone. The cutaneous pythiosis lesions were completely recovered at 35 ± 7 and 60 ± 5 days after the surgical excision with topical DMSO and surgical excision alone, respectively.

The combination of surgical excision and topical DMSO is found an effective treatment for cutaneous pythiosis in horses.

Corynosoma is a parasite from the Acanthocephala phylum with worldwide distribution. Corynosoma parasites are found in pinnipeds as their definitive host.

This study aimed to investigate the morphological and molecular characteristics of Corynosoma, and its histopathological effect on the intestinal tissue of Pusa caspica.

A severe Corynosoma infection was observed in the small intestine of a juvenile male Caspian seal (P. caspica). The morphological descriptions were done using light microscopy, and scanning electron microscopy (SEM). The molecular diagnosis was performed using partial sequences of internal transcribed spacer 1 (ITS1) and 5.8S ribosomal RNA (rRNA) gene.

According to the results, the Corynosoma specimens were identified as Corynosoma caspicum. The histopathological inspection of intestinal tissue revealed lesions in epithelial cells, mucosa, submucosa and muscle layers, destruction of intestinal glands, and infiltration of inflammatory cells.

Presence of such a severe infection in one of the individual Caspian seals can suggest the possibility of morbidity among other seals in the landlocked Caspian Sea. Thus, further research on their parasite infections is required for understating the status of the Caspian seal population and conserving this endangered species.

Fowl adenoviruses (FAdVs) associated with certain clinical diseases including inclusion body hepatitis (IBH) have become of considerable importance in the poultry industry. Currently, an increasing number of IBH outbreaks in different parts of Iranian poultry industries is a growing concern. Infectious bursal disease virus (IBDV) or chicken infectious anemia virus (CIAV) have historically been incriminated as predisposing factors for FAdVs to cause IBH. Furthermore, some have speculated whether IBDV vaccine strains impact on IBH clinical manifestation. The present report assesses the potential predisposing role of IBDV, CIAV, and infectious bursal disease) IBD( vaccine strains for FAdVs in the course of an IBH occurrence in the field.

Case description:

 90000 day-old broiler chickens with the same parent source were housed, at 4 day-interval, in two commercial farms in Shiraz, Iran. Increased mortality with lesions of hepatitis, suggestive of IBH, started in the primitive farm right after blind prescription of IBD vaccine at the age of 12-days-old. Consequently, IBD vaccination was postponed for the apparently healthy chickens of the other farm in which chickens were monitored for the occurrence of IBH afterwards. Laboratory examination was followed by histopathology and polymerase chain reaction (PCR) on liver, cloacal bursa, and thymus samples to determine the involvement of FAdV, IBDV, and CIAV in the occurrence of the disease.

Findings/treatment and outcome:

 No evidence was found to support the predisposing role of neither IBD vaccination nor IBDV/CIAV infection in this IBH occurence. The results also demonstrated a primary role of the FAdV-11 as a causal agent of the IBH occurrence.

The findings suggest that certain FAdVs are pathogenic enough to primarily induce IBH in young broilers.