Iranian Journal of Veterinary Research
Volume:25 Issue: 3, Summer 2024

Spoilage is very common in vacuum-packed sliced emulsion-type sausages during refrigerated storage.

This study aimed to investigate the inhibitory effects of cell-free supernatant (CFS) of lactic acid bacteria (LAB) on the spoilage bacteria isolated from vacuum-packed sliced emulsion-type sausages as biological preservatives.

These products from various companies were examined to find the spoilage bacteria. A total of 43 LABs were screened for inhibitory activity against the spoilage bacteria. The MIC90 of protective bacteria and the inhibitory effect of different components obtained from these bacteria was investigated.

Four LAB were confirmed as the predominant spoilage bacteria, including Enterococcus mundtii, Latilactobacillus sakei, Latilactobacillus curvatus, and Weissella viridescens. Six strains, including Lactobacillus acidophilus ATCC 4356, Lactobacillus helveticus PTCC 1332, Lactiplantibacillus plantarum CEC 17484, Lactiplantibacillus plantarum LL441, Lacticaseibacillus rhamnosus ATCC 53103, and Pediococcus acidilactici DSM 20284 were able to produce proteinaceous antimicrobial metabolites against the four spoilage agents, which were selected as protective bacteria. CFS of the protective bacteria inhibited four spoilage bacteria by more than 88%. The MIC90 of all protective bacteria was less than 10 mg/ml against E. mandetii and L. sakei. After neutralizing acid and H2O2 of the CFS of P. acidilactici, it was still quite effective against E. mandetii and L. sakei. The sausage’s pasteurization temperature did not affect the bacteria’s active metabolites.

The substances derived from these bacteria can be applied as biopreservatives in sliced sausage, even in the pre-pasteurization stage of these products.

Pets are exposed to a multitude of carcinogenic substances in the modern world. Consequently, high rates of cancer are observed, particularly in middle-aged cats and dogs. Although bisphosphonates have been incorporated into the treatment of human cancers, there are few animal-specific studies. As the number of cancer cases in animals continues to rise, it becomes increasingly important to evaluate anticancer drugs on a species-specific basis.

The present study aimed to examine the impact of zoledronic acid (ZA) on apoptotic pathways in canine osteosarcoma (OSA) cell lines.

The apoptotic effects of ZA administration on D-17 canine OSA cells were analysed by determining apoptotic DNA breaks, caspase-3, -8 and -9 levels by ELISA method and Bax/Bcl-2 ratio by qRT-PCR. The effect of ZA on the colony formation capacity of cells was evaluated by crystal violet staining method. The mineral binding capacity of ZA application in cells was investigated by Alizarin Red S staining technique. The change in alkaline phosphatase enzyme activity in OSA cells due to ZA treatment was determined using the colorimetric method. The antimetastatic effect was determined using the wound healing method, which evaluated the migration potential of cells.

While ZA application did not show a significant cytotoxic effect in the cells in the first 24 h, a decrease observed in the viability of the cells depending on the increasing dose and time. Low dose ZA (1, 5, 7.5, 10 µM) concentrations increased mineral content and alkaline phosphatase enzyme activity. A significant decrease was found in the expression levels of survivin, which determines the cell survival, depending on the dose and time.

It is expected that our obtained data will contribute to the more effective treatment of the disease by creating different treatment options for clinicians in the light of increasing knowledge in cancer cell biology.

In acute alkali corneal burns, the routine treatment protocol includes suppressing inflammation using corticosteroids. In recent years, there has been a growing interest in the role of insulin in wound healing research due to its remarkable positive effects.

The present study aimed to compare the healing effects of dexamethasone -the conventional approach- and NPH-insulin on alkali corneal burns.

An alkali corneal burn was created using Ca (OH)2 in all subjects. One group (n=6) was treated with an ophthalmic ointment containing dexamethasone (group I), and another group (n=6) was treated with an insulin ointment (group II). The control group (n=6) received no treatment (group III). Clinical changes in the corneal burn areas were monitored on days 3, 7, 14, and 21. The animals were euthanized on day 21. The excised corneas were examined for histopathological, immunohistochemical, and biochemical changes.

A more successful clinical recovery graph was drawn for group II. Particularly, a significant (P<0.05) improvement was detected in group II on day 21. The highest positivity in MMP-9 corneal staining was found in group I. Group II had a significant (P<0.05) increase in total antioxidant capacity (TAC) values. The treatment groups showed a significant (P<0.05) decrease in total oxidant content (TOC) values and a significant (P<0.05) increase in reduced glutathione (GSH) levels as compared with the control group.

Topical NPH-insulin provided rapid and uncomplicated clinical recovery of alkali corneal burns. Insulin and dexamethasone showed similar effects like increased antioxidant molecules and decreased oxidant substances which indicated that insulin may prevent free radical formation in the cornea.

Peste des petits ruminants virus (PPRV) is one of the most economically important pathogens in sheep and goats. Fusion (F) and Hemagglutinin (H) proteins are the main immune-stimulating antigens.

The present study aimed to clone and express F and H genes in baculovirus, and evaluate the immunogenicity of recombinant proteins produced by sf9 cells in mice.

Amplified F and H genes (by RT-PCR using specific primers) were cloned into pFastBac Dual plasmid. The recombinant plasmid was transformed in DH10Bac host cells. SDS-PAGE and Western blotting was performed to control the recombinant protein, and a whole pure and specific recombinant protein was obtained.

The immunogenicity of 20 μg of non-adjuvant recombinant proteins in Balb-c mice showed better results compared with the attenuated PPR vaccine.

The recombinant protein obtained from this study can be a suitable candidate for the production of recombinant vaccines against PPRV.

Arcobacter butzleri, the most common genus of the Campylobacter family, is considered an emerging zoonotic pathogen.

This study aimed to evaluate A. butzleri from diverse sources, in order to determine the antibiotic resistance pattern of isolates and the frequency of some genes responsible for their antibiotic resistance.

In this study, 425 samples were collected from different sources (chicken slaughterhouse sewage, poultry meat, beef, sheep meat, dairy products) during different seasons of 2020-2021. Suspicious colonies were confirmed using biochemical tests. Furthermore, the polymerase chain reaction technique was used to confirm the phenotypic results using the 16S rRNA gene. The antibiotic resistance pattern of the isolates to 16 antibiotics were determined using the disk diffusion method. Also, the minimum inhibitory concentration (MIC) of their growth was detected using the tube dilution method in the presence of tetracycline, erythromycin, and gentamicin.

A total of 53 isolates of A. butzleri (12.5%) were isolated from (chicken slaughterhouse sewage=36, poultry meat=8, beef=4, sheep meat=5), which contain all three antibiotic resistance genes of abu_0814 (90.57%), OXA_464 (100%), and gyrA (83.02%). The findings of the present investigation showed the presence of A. butzleri in different sources and the high prevalence of antimicrobial resistance in the isolates. Nineteen isolates (36%) have extensive drug resistance and 34 isolates (64%) showed multi-drug resistance to the used antibiotics.

The elevated level of antibiotic resistance observed in A. butzleri isolates originating from various samples suggests a significant use of antibiotics and a prevalent environmental contamination.

Brucella outer membrane proteins (OMPs) are highly immunogenic, and lipopolysaccharides (LPS) are also considered significant antigens, making them potential candidates for subunit vaccines.

To investigate the effects of Brucella OMPs and LPSs on mouse bone marrow-derived dendritic cells (BMDC) activation and T-lymphocyte proliferation.

BMDC were isolated and cultured in vitro, and subsequently co-cultured with Brucella recombinant proteins (rOMP10, rOMP19, rBP26, rOMP25, and rOMP31), as well as smooth LPS (S-LPS) or rough LPS (R-LPS). The expression of maturation markers on the surface of BMDCs was determined using flow cytometry, while the expression of TLR receptors was determined using RT-PCR. The levels of inflammatory cytokines were measured using iELISA, and the impact on the proliferation of mouse T-lymphocytes was assessed using the MTT method.

The impact of LPS on BMDC maturation, TLRs-mediated cytokine secretion, and antigen presentation was found to be limited. In contrast, rOMP10, rOMP19, and rBP26 were observed to promote BMDC maturation, increase the expression of TLR-2 and TLR-4 mRNA, and activate T-lymphocyte proliferation by significantly increasing the expression of pro-inflammatory cytokines (TNF-α, IFN-γ, IL-6, IL-12) and antigen-presenting molecules. However, rOMP25 and rOMP31 did not promote BMDC maturation, inhibited the expression of MHCI and MHCII antigen-presenting molecules, and increased the expression of inflammation-suppressing cytokines (IL-10 and IL-4), resulting in the inhibition of T-lymphocyte proliferation.

Brucella OMP10, OMP19, and BP26 play an important role in activating the host immune response, while OMP25 together with OMP31 may play a role in Brucella immune escape.

Follicular fluid (FF) is a biological fluid that contains many compounds such as proteins, hormones, metabolites, antioxidants, etc.

The purpose of this research is to investigate the effects of adding cattle and human follicular fluid on bulls’ semen quality during the freezing process.

Semen sampling from 12 Simmental bulls was performed in a period of 3 months (36 ejaculations with three ejaculates per bull). Each ejaculate was divided into four equal portions. Three portions were used for control (C) (semen without follicular fluid), semen containing human follicular fluid (HFF), semen containing cow follicular fluid (CFF). Another part of semen was also used to prepare seminal plasma. Sperm quality assessment was performed on fresh and thawed frozen (immediately after thawing, 1 and 2 h after thawing) semen.

Adding human follicular fluid to the bulls’ semen can slow down the process of reducing sperm motility and can delay the increase in the percentage of dead sperm in frozen-thawed semen.

The human follicular fluid maintains the viability and motility of bull sperms better than the control and bovine follicular fluid. The possible effect of human follicular fluid on the metabolism of sperms during the process of freezing and thawing needs to be clarified in future studies.