Iranian Journal of Veterinary Research
Volume:22 Issue: 2, Spring 2021

Campylobacter fetus subsp. fetus is the causal agent of sporadic abortion and infertility in bovines that produces economic losses in livestock.

This study evaluates the capability of C. fetus subsp. fetus to invade and survive in bovine endometrial epithelial cells and attempts to describe a pathogenic mechanism of this microorganism.

Primary culture of bovine endometrial epithelial cells was challenged with C. fetus subsp. fetus. Intracellular bacteria, represented by the number of genomic copies (g.c.) were quantified at 0, 2, 4, 10, and 24 hours post-infection (h.p.i.), by quantitative polymerase chain reaction (qPCR). The presence of intracellular bacteria was evaluated by immunofluorescence and immunohistochemistry.

The results showed that only viable C. fetus subsp. fetus could invade endometrial cells. The g.c. number in assays with viable C. fetus subsp. fetus reached an average value of 656 g.c., remained constant until 4 h.p.i., then decreased to 100 g.c, at 24 h.p.i. In assays with non-viable microorganisms, the average value of g.c. was less than 1 g.c. and never changed. The intracellular presence of this bacteria was confirmed at 2 h.p.i. by immunofluorescence and immunohistochemistry.

The results suggest that only C. fetus subsp. fetus viable can invade bovine endometrial epithelial cells but will not replicate in them, indicating that the endometrial cells do not represent a replication niche for this pathogen. Nonetheless, this invasion capability suggests that this type of cell could be employed by the pathogen to spread to other tissues.

Probiotics may improve milk quality and the general health status of animals.

The effects of dietary Bacillus coagulans PRM101 on milk components, milk fatty acids (FA), and some health indicators of dairy cows were investigated.

The probiotic was added to the feed of 12 Holstein cows (2 g/cow: 2 × 1011 CFU/cow) for 63 days compared to a control group fed on the basal ration (n=11). Milk and blood samples were taken on days 0, 21, 42, and 63.

The yields of milk and energy corrected milk (ECM; computed from milk weight and its fat and protein content) decreased linearly and similarly (P=0.60) in both groups. The treatment cows, however, showed quadratic increases in the weights of milk (P=0.03) and ECM (P=0.04) at d42 of the study. Energy corrected milk (d42, p <0.05) and crude protein content of milk (d42, p <0.05; d63, p <0.1) were higher in the cows receiving the probiotic. The proportions of heptadecanoic (C17:0; P=0.002) and linoleic (C18:2; P=0.077) acids in milk fat (g/100 g fat) were higher in the treatment cows on d63. Milk total antioxidant capacity (TAC), malondialdehyde (MDA), and similarly, amyloid A (AA) and haptoglobin (Hp) of milk and blood were not affected. Total antioxidant capacity and MDA were negatively correlated in the control group (r=-0.669, P=0.005). Heptadecanoic acid correlated negatively with milk MDA (r=-0.611, P=0.035) and positively (r=0.591, P=0.043) with serum Hp in the treatment cows.

Dietary B. coagulans PRM101 may improve the proportions of C17:0 and C18:2 FA in milk. Some improvements in milk protein and the health status of the cows may also be anticipated.

Hydranencephaly is the unilateral or bilateral loss of cerebral hemispheres and their replacement by a cerebrospinal fluid-filled sac that is caused by some teratogenic viruses. This disorder can be recognized before death occurs, using computed tomography (CT) scan. Pathological findings are also useful for the confirmation of the diagnosis.

The aim of this study was to determine features of hydranencephaly in calves by CT.

In this study, CT images were obtained from the skulls of 7 same-age calves with neurological signs, affected by Akabane virus, after slaughter. To compare the Hounsfield unit (HU) obtained from each brain region with the normal one, a normal calf’s (with the same age) CT images were considered. Then, HU was measured in different parts of the affected calves’ brain and compared with the normal calf’s brain.

Computed tomography images of affected calves indicated a hypoattenuated density of cerebral hemispheres, and the mean value of HU significantly decreased in these parts of the brain compared to normal calves (P=0.0001). There was no statistically significant difference between the mean value of the brain stem HU of the affected calves and the normal ones (P=0.066). In the gross pathology, asymmetric fluid-filled sacs that replaced cerebral hemispheres were observed, but the brain stems were intact in all cases.

The results showed a strong correlation between CT scan and pathology findings in calves with hydranencephaly. This is the first CT scan-mediated study of calves with hydranencephaly.

Staphylococcal enterotoxins (SEs) are produced in foods under favorable conditions and considered a potential biological threat.

The study was performed to detect enterotoxigenic genes of A and B in coagulase-positive (CPS) and coagulase-negative staphylococci (CNS) to evaluate biotypes and antibiotic resistance of isolated Staphylococcus aureus from different meat.

A total of 160 meat swab samples were collected from lamb, water buffalo, cattle, and chicken carcasses. Presumptive colonies on Baird Parker agar were subjected to biochemical identification, including Gram staining, catalase, oxidase, and coagulase activity. Relevant colonies separately were subjected to the polymerase chain reaction (PCR) assay for identification of Staphylococcus genus, enterotoxigenic genes (sea and seb) and the thermonuclease gene (nuc) specific for the S. aureus. The antibiotic susceptibility test was also carried out using five antibiotics.

Totally, 150 Staphylococcus spp. were isolated from the samples among which 135 (90%) isolates harbored sea gene, meanwhile, none of the isolates contained seb gene. Twenty-five S. aureus confirmed by PCR from which 15 isolates (60%) belonged to host specific (HS), 7 isolates (28%) belonged to non-host specific (NHS) biotypes, while 3 isolates (12%) were non-typable. Overall, 68%, 56%, 16%, 12%, and 8% of isolates were resistant to penicillin, trimethoprim, gentamicin, oxacillin, and erythromycin, respectively.

The meats provided from this area were contaminated with enterotoxigenic and antibiotic-resistance staphylococci, which can threaten the health of the consumers. The study showed that not only CPS contain enterotoxin A gene, but also CNS isolates possess this gene, especially in buffalo meat, and thus they are recognized as potential hazards in different meats.

Canine leptospirosis is a serious public health concern.

This study aims to investigate the feasibility of conserved first to fifth domains of recombinant Leptospira immunoglobulin like protein B antigen (rLigBCon1-5) as a serodiagnostic marker for detecting canine leptospirosis.

A total of 340 unvaccinated canine serum samples were screened using microscopic agglutination test (MAT) and rLigBCon1-5 based immunoglobulin G (IgG) indirect-enzyme-linked immunosorbent assay (I-ELISA). Further, 60 vaccinated canine sera were screened using MAT and rLigBCon1-5 based latex agglutination test (LAT).

Microscopic agglutination test results revealed seropositivity of 28.6%. The relative sensitivity, specificity, and accuracy of IgG I-ELISA in comparison to MAT were 100%, 96.0%, and 97.2%, respectively. Out of 60 vaccinated sera, 46 sera reacted with MAT alone, and eight sera reacted by both tests, while six sera were non-reactive with both tests. Anti-LigB antibodies were detected in eight canine sera by rLigBCon1-5 based LAT. In five LAT reactive sera, agglutinins of locally circulating Leptospira serovars Grippotyphosa (n=4) and Australis (n=1) were detected. In three LAT reactive sera, agglutinins against Icterohaemorrhagiae (n=3) produced due to natural infection were present.

Immunoglobulin G based indirect ELISA assay (IgG I-ELISA) can be employed as an alternative test instead of MAT. rLigBCon1-5 based LAT detected anti-LigB antibodies in eight vaccinated sera where the vaccine failure occurred partially or totally due to the limited efficacy spectrum of Nobivac® RL and cold chain breakage. This vaccine could not provide cross-protection against locally circulating Leptospira serovars. The recombinant LigBCon1-5 antigen based LAT possesses capability of differentiating infected from vaccinated individuals (DIVA capability) when employed as a pen-side test for detecting canine leptospirosis.

The quality of shrimp, as high perishable seafood, can readily be effected by microbial, chemical, and physical alterations during storage.

In this study, carboxymethyl cellulose (CMC) coating either alone or incorporated with variable levels of clove oil nanoemulsion (CNE) (10, 20, and 30 mg/ml) was developed to sustain the quality of shrimp during refrigerated storage.

Changes in microbial, chemical, textural, color (L*, a*, b*), and sensory parameters of the studied groups evaluated through distinct experimental approaches.

Based on our results, the pattern of increase in the aerobic plate count (APC) and psychrotrophic bacterial count (PBC) in different groups were reported as the following order: CMC + CNE < CMC < control. Also, CMC and CNE integration decreased the upward trend of total volatile basic nitrogen (TVB-N), and thiobarbituric acid reactive substances (TBARS) compared to that of the control group during storage at 4°C for 10 days (P<0.05). During the storage period, the decrease of the L* value in the control group was greater than the others; whereas, the lowest a* and b* values were observed in this group (P<0.05). Besides, the textural and sensory properties of coated shrimp were significantly more acceptable (P<0.05).

Integration of CNE in CMC coating promisingly improves the quality of shrimp during refrigerated storage.

Incidences of production and metabolic diseases in dairy cows have increased over the last few decades because of the increasing trends in milk production. Production diseases cause different and distinct depressions in milk production that lead to different and major economic losses in large dairy herds.

The objective of this study was to determine milk production depression and its economic losses due to different production diseases in selected large dairy herds of Iran.

Production and health data from 17 large dairy herds with a total of 146464 observations across three parities were obtained. Milk yield depressions were estimated for three phases of lactation including 1) 5-60, 2) 61-120, and 3) 121-180 days in milk. Data were analyzed using Mixed Models of SAS program (v. 9.3) with fixed effects of the diseases, calving year, calving month, parity, and herd with cow age at calving as covariates.

The data demonstrated significant effects of different production diseases on milk production depression during 5-60, 61-120, and 121-180 days in milk (P<0.05). During 5-60 days in milk, ketosis, displaced abomasums (DAs), laminitis, mastitis, metritis, retained placenta (RP), and dystocia resulted in, respectively, 253, 682, 39, 38, 110, 215, and 55 kg of milk yield depressions that were equivalent to 38.5, 103.7, 6.0, 5.8, 16.7, 32.6, and 8.4 U.S. Dollars (USD) economic losses. Milk yield depressions due to laminitis and mastitis over the 180 days in milk were, respectively, 207 and 404 kg equivalent to 31.5 and 63.0 USD economic losses. Since the milk yield depression constitutes about 20-35% of total costs of production and metabolic disorders, the total economic losses would be 3-5 times the above values.

Displaced abomasum and laminitis caused the highest and lowest depressions in milk yield, respectively. The findings suggest that commercial dairy production management strategies in Iran require reassessment and refinement. Overfeeding of concentrates should be ceased. Future economic and reproductive studies are needed to enable developing effective strategies for optimizing modern and postmodern dairy production in Iran.

Micro-computed tomography (µCT), a modern imaging technique, provides detailed information on the bone morphology of small animal models.

The objectives are 1) to produce three dimensional (3D) models from µCT images of femoral and tibial bones of New Zealand rabbits, and 2) to estimate and compare morphometric and volumetric results among genders as well as left and right sides.

A total of twenty adult New Zealand rabbits (10 females, 10 males, aged 12-18 weeks, weight= 2.5-3 kg) were used for this study. ‏‏Three dimensional reconstructed models of the femoral and tibial bones of rabbits were created from cross-sectional images of µCT using the 3D Slicer program. Anatomical structures were determined on these 3D bone models. Afterward, morphometric parameters such as length, thickness, and width of various parts of the bones were calculated with volume and volume ratio values of cortical bone, trabecular bone, and medullary cavity.

The gender*laterality interaction term was found statistically significant in measurements of femoral diaphysis diameter (FDD), internal femoral diaphysis diameter (IFDD), femoral head diameter (FHD), tibial diaphysis diameter (TDD), tibial distal width (TDH), and tibial proximal width (TPW) (p <0.001). The gender*laterality interaction term was not significant in volume and volume fraction values of cortical bone, trabecular bone, and medullary cavity (P>0.05).

It is thought that the study will contribute to the orthopedic experimental studies of rabbits for femoral and tibial bones and will bring a modern perspective to the field of veterinary anatomy.

Diarrhea is the most severe disease affecting small ruminant farms, even though there is continuous progress in the control and prevention strategies.

This study aimed to identify some of the risk factors associated with diarrhea in small ruminants in Kuwait.

Faecal samples from 556 animals (334 sheep and 222 goats) were collected and examined for different enteropathogens. The collected data from animals and herd management were finally analysed.

Statistical analysis identified that age (pre-weaned; P=0.022, OR=2.38), herd size (large; P=0.037, OR=1.7), and season (dry; P=0.022, OR=2.39) were as non-infectious risk factors of the diarrhea occurrence. It was found that Escherichia coli K99 (P=0.000, OR=7.7), Cryptosporidium spp. (P=0.000, OR=586), and Eimeria spp. (P=0.000, OR=2.97) were reported more frequently in diarrheic animals than non-diarrheic ones.

Pre-weaned small ruminants reared in the large herd were more susceptible to diarrhea. Escherichia coli K99, Cryptosporidium spp., and Eimeria spp. were the most predominant enteropathogens causing diarrhea in small ruminants in Kuwait. Diarrhea was more common in dry season than in wet season.

The pin and tension band wire (PTBW) technique is used to convert the tensile force at the olecranon fracture site. Although metal wire can be used for the tension band technique, it has side effects such as skin irritation or infection. Other fixation materials like a high-strength polyester and polyethylene suture that do not cause skin irritation and pain, provide similar mechanical strength.

The aim of this study was to compare olecranon fragment stability by applying tension bands using metal wire and FiberWire of identical tensile strength.

This study was designed as ex vivo biomechanical test on canine cadaveric elbows. We biomechanically analyzed the following two fixation methods in cadaveric elbows with olecranon osteotomies: (1) Kirschner (K) wire with 0.76 mm metal wire tension band, (2) K-wires with No. 2 FiberWire tension band. A tensile testing machine was used to measure displacement.

It was measured that the mean maximum load (MML) value and mean yield load (MYL) were higher using No. 2 FiberWire as a tension band than 0.76 mm metal wire.

Biomechanical strength of No. 2 FiberWire was significantly different from 0.76 mm metal wire in a canine model of olecranon osteotomy. So, FiberWire is applicable instead of metal wire that has a similar strength.

Newcastle disease (ND) has been categorized as a highly contagious viral disease, remaining as a constant threat to both wild birds and commercial chickens.

In this study, we recovered and characterized the avian orthoavulavirus 1 (AOaV-1) strain, nominated as EM1, from the Eurasian magpie (Pica pica).

The nucleotide and amino acid sequence of the fusion protein (F protein) of EM1 were determined and its phylogenetic relationship was investigated with well-characterized AOaV-1 genotypes, which originated from wild bird species and chickens around the world.

Phylogenetic analysis and deduced amino acid sequences of the F gene revealed that EM1 virus belonged to VIIl sub-genotype viruses with the characteristic multibasic amino acid sequences associated with the velogenic motif as 112RRQKRF117 at the cleavage site of its precursor fusion protein. EM1 shared a high level of similarity to the other virus sub-genotypes in nucleotide and amino acid sequences of F protein. Furthermore, the evolutionary difference between the studied virus and viruses belonging to the VIIl sub-genotype indicated that a close relatedness and the possibility of a common origin.

These results show that the virulent AOaV-1 of sub-genotype VIIl is circulating continuously in Iran, and is disseminating among wild and domestic bird species that can cause bidirectional spillover infection. Therefore, further epidemiological studies can be beneficial in the assessment of the evolution of AOaV-1 in its hosts and will help us to be well-equipped in facing the emergence of new sub-genotypes of this virus.

Intervertebral disc herniation (IVDH) is one of the common causes of spinal cord injury (SCI) in dogs. It is commonly treated by performing surgical decompression that involves the removal of the extruded disc material. However, the recovery rates after surgical interventions are variable and many times unsatisfactory. This report aims to document a case of paraplegia associated with IVDH in a Beagle dog and its therapeutic management using allogenic bone marrow-derived mesenchymal stem cells (aBM-MSCs).

The dog was presented with paraplegia that was initiated three weeks back. Based on the findings of computed tomography (CT), the condition was diagnosed as Hansen type I IVDH at T12-T13 intervertebral space. Findings/treatment and outcome: Neurological examination was performed to grade the neurological deficit. The isolation, culture, and characterization of aBM-MSCs were done as per the standard protocol. The prepared cell suspension of aBM-MSCs was percutaneously transplanted to the spinal cord parenchyma at the site of injury. A total of four doses of 1 × 106 cells were given at an interval of 15 days along with methylcobalamin and gabapentin orally. Improvement was evaluated based on the neurological examination and grading. Considerable improvement was noticed after the first dose of aBM-MSCs. The animal started complete weight bearing on its pelvic limbs after two doses.

Percutaneous transplantation of aBM-MSCs might have played an important role in reversing the neurological deficits secondary to IVDH in this dog. Further studies are required preferably in a larger population to confirm the efficacy of aBM-MSCs therapy in ameliorating neural deficits associated with IVDH.