جستجوی مقالات مرتبط با کلیدواژه « bovine » در نشریات گروه « دامپزشکی »

Bacillus licheniformis is a gram-positive, endospore-forming, saprophytic and facultative anaerobe that is resistant to heat and environmental conditions. This study was the first to isolate and confirm B. licheniformis as a cause of bovine mastitis in Iran. In the summer of 2020, 105 samples of mastitic milk were collected from dairy farms around Tehran and sent to the microbiology laboratory of the Faculty of Veterinary Medicine at the University of Tehran. The bacterial pathogens were identified using selective and differential culture media and confirmed by PCR to contain the toxin synthetase genes licA, licB and licC in mastitic isolates of B. licheniformis. Resistance patterns to 19 antibiotics were determined for two isolates of B. licheniformis. Staphylococcus aureus and Escherichia coli were identified as the most important organisms in the samples. B. licheniformis was isolated from the two samples containing all three genes. Both isolates were resistant to streptomycin, trimethoprim-sulfamethoxazole, cefixime, ampicillin, bacitracin, clindamycin, and gentamicin. B. licheniformis was reported for the first time in Iran as a cause of bovine mastitis with clinical symptoms. The first isolation of toxin-producing strains of B. licheniformis from mastitic cows in Iran raises concerns about the safety of dairy products. In principle, selected strains with toxigenic potential should not be used as feed additives and animal feed. However, whole genome sequencing is proposed to search for genes coding for toxins.

Peste des petits ruminants (PPR) or goat plague is considered a leading, highly contagious, and most lethal infectious viral disease of small ruminants affecting the worldwide livestock economy and international animal trade. Although sheep and goats are the primarily affected, the PPR Virus (PPRV) host range has expanded to other livestock (large ruminants) and wildlife animals over the last few decades, resulting in serious concern to the ongoing PPR global eradication program, which is primarily optimized, designed, and targeted towards accessible sheep and goat population. A systematic review and meta-analysis study was conducted to estimate the prevalence and spill-over infection of PPRV in large ruminants (bovine and camel) and wildlife. Published articles from 2001 to October 2021 on the "PPR" were searched in four electronic databases of PubMed, Scopus, Science direct, and Google Scholars. The articles were then selected using inclusion criteria (detection/prevalence of PPRV in bovine, camel, and wildlife population), exclusion criteria (only sheep or goats, lack of prevalence data, experimental trial, test evaluation, and reviews written in other languages or published before 2001), and the prevalence was estimated by random effect meta-analysis model. In the current study, all published articles belonged to Africa and Asia. The overall pooled prevalence of PPR estimates was 24% (95% CI: 15-33), with 30% in Asia (95% CI: 14-49) and 20% in Africa (95% CI: 11-30). The overall estimated pooled prevalence at an Africa-Asia level in bovine and camel was 13% (95% CI: 8-19), and in wildlife, it was 52% (95% CI: 30-74) with significant heterogeneity (I2 = 97%) in most pooled estimates with a high prevalence in atypical hosts and wildlife across Asia and Africa. Over the last two decades, the host range has increased drastically in the wildlife population, even for prevalent PPR in the unnatural hosts only for a short time, contributing to virus persistence in multi-host systems with an impact on PPR control and eradication program. This observation on the epidemiology of the PPRV in unnatural hosts demands appropriate intervention strategies, particularly at the livestock-wildlife interface.

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.

Gastrointestinal dysmotility is important in ruminants. Pulegone is a natural monoterpene ketone obtained from the essential oil of different plants. It has been reported that pulegone has an antibacterial, antifungal, and anti-histamine effect. The present study investigated the effects of pulegone on bovine ileum smooth muscle contractions. The experiment was performed on the circular smooth muscle of ileum samples taken from slaughtered bovine in the organ bath. Seven cumulative concentrations of pulegone from 1 to 1000 µg ml-1 were added to tissue samples. The solution used was Tyrode’s solution aerated with a mixture of 95% oxygen and 5% carbon dioxide, and the temperature was set at 37 °C. The effect of pulegone on baseline contractions and three induced contractions with barium chloride (BaCl2), potassium chloride (KCl), and carbachol (Cch) was investigated. The results revealed that pulegone significantly inhibits spontaneous, as well as all spasmogen-induced contractions. Pulegone was able to relax the contractions caused by Cch, BaCl2, and KCl (20) at 30 µg ml-1. The anti-spasmodic properties of pulegone can be employed for the treatment of intestinal spasms or hypermotility.

Uterine diseases are common problem that influence the reproductive output in dairy farm. Different factors include metabolic disturbances may affect the uterine defense mechanism and contribute at postpartum uterine disease occurrence. The routine metabolic profile is measurements of net values of non-esterified fatty acids (NEFA), β-hydroxybutyric acid (BHBA), and glucose (Glc) in cow serum. The present study aimed to look at the ratios of the energy metabolic products during the transition period and investigate their relationship with bovine clinical endometritis. The weekly serum samples were collected from 100 dairy cows during the transition period (2 weeks prepartum to 3 weeks postpartum). In the clean test (Day 30 postpartum), 16 cows were selected, and assigned in a case-control repeated measure design into two groups as clinical endometritis (CE: n=8) or healthy cows (n=8). The respective serum samples of the cows were assayed for NEFA, BHBA, and Glc. All the measurement units were converted to mM/L and the ratios were calculated. The trend of changes in the ratios of NEFA to BHBA was in a steady state in healthy cows during the transition period, while it raised at the time of parturition in the CE group (P<0.05). While the significant increase in NEFA to Glc ratio started after parturition in healthy cows, it was begun to increase before parturition in CE. The trend of changes in the energy metabolite ratios during the transition is different in CE compared to healthy dairy cows.

The aim of this study was to investigate the presence of caprine herpes virus-1 (CpHV-1) and bovine herpes virus-1 (BoHV-1) in 269 goat sera collected from small-scale family farms located in six provinces within the Black Sea region of northern Turkey. The overall seropositivity for alpha-herpesvirus in the native goats was found as 19.33% using BoHV-1 glycoprotein B (gB)-blocking enzyme-linked immunosorbent assay (ELISA). Additionally, the seroprevalence of BoHV-1 was determined in 5.20% of the goats using virus neutralization test. To distinguish between CpHV-1 and BoHV-1, the combinations of gB/gE-blocking ELISA tests were performed. Of tested samples, 15.24% were CpHV-1 seropositive; whereas, 4.09% were BoHV-1 seropositive. The results indicated that CpHV-1 is in circulation among local goats of northern Turkey. Considering the close relationship between BoHV-1 and CpHV-1, the transmission of BoHV-1 via goats may also be one of the predisposing factors involving in the spread of virus among the surrounding cattle.

Bovine subclinical mastitis is regarded as a devastating disease due to the economic costs imposed on dairy husbandry. Moreover, it is a hazard in the public sector in the cases of zoonotic bacteria because of the potential role of unpasteurized milk and dairy products to propagate the infectious agent to the human food chain. The present study aimed to evaluate the frequency, virulence content, and antimicrobial resistance profile of Shiga toxin-producing Escherichia coli (STEC) strains isolated from bovine subclinical mastitis in Kurdistan Province, West of Iran. A total of 400 bovine subclinical mastitis milk samples recognized in the California Mastitis Test were collected aseptically and analyzed for the presence of E. coli phenotypically and molecularly. The isolates were genotypically screened for stx1, stx2, and eae genes. Furthermore, O157:H7 STEC strain was searched among the isolates in a duplex polymerase chain reaction. The antimicrobial resistance scheme of the isolates was determined using the agar disk diffusion method. In general, 173 (43.25%) E. coli isolates were detected among which 39 (22.54%) isolates were STEC. The frequency of STEC virulence genotypes was stx2 (25 isolates, 64.10%), stx2+eae (6 isolates, 15.38%), stx1+stx2 (6 isolates, 15.38%), and stx1+stx2+eae (2 isolates, 5.12%). In addition, three O157: H7 strains were identified with the genetic content of stx1+stx2+eae (2 isolates) and stx1+stx2 (1 isolate). The most prevalent antimicrobial resistance was observed against streptomycin, tetracycline, and ampicillin. Gentamycin, amoxicillin-clavulanic acid, and trimethoprim-sulfadiazine were the most effective antibiotics against O157 strains, whereas gentamycin, ciprofloxacin, and nitrofurantoin were effective against non-O157 strains. The results revealed the significant role of STEC in bovine subclinical mastitis in the studied region. In addition, the distribution of O157:H7 strain and high prevalence of multidrug resistance among the isolates is a matter of concern. Therefore, there is a potential threat of human infection following the consumption of contaminated milk with STEC in Kurdistan Province, Iran.

The use of C-type natriuretic peptide (CNP) combined with cysteamine during pre-in vitro maturation (IVM) can help establish an effective pre-IVM system.

This study was designed to investigate the effects of CNP combined with cysteamine on meiotic maturation and developmental competence of bovine oocytes in vitro.

Oocytes were cultured in pre-IVM medium supplemented with 100 nM CNP for 6 h in the absence or presence of 100 μM cysteamine, followed by standard IVM for 24 h. Oocytes matured by standard IVM for 24 h (no pre-IVM) were used as the control. The percentage of oocytes arrested at germinal vesicle (GV) stage in each treatment group was examined at 0 h of IVM, and the nuclear maturation rate was assessed by evaluating the percentages of oocytes that reached metaphase II (M II) stage at 24 h of IVM. After 24 h of IVM, oocytes were subjected to in vitro fertilization (IVF) and in vitro embryo culture (IVC). Cleavage rates were assessed 48 h post-insemination. Blastocyst production rates were recorded on day 8 after IVF. In addition, intra-oocyte glutathione (GSH) and reactive oxygen species (ROS) content for each treatment were tested at 0 h and 24 h of IVM.

No differences were observed between the CNP pre-IVM treatment and control groups in the rate of bovine oocytes maturing to the M II stage, cleavage and blastocysts production rates after IVF, and intra-oocyte GSH levels. Notably, the presence of cysteamine during pre-IVM culture with CNP significantly improved the rate of embryos developed to the blastocyst stage after in vitro maturation and fertilization, moreover, it increased the levels of GSH and reduced the levels of ROS in bovine oocytes.

The improvement to IVM bovine oocyte developmental competence through pre-IVM with CNP combined with cysteamine may be associated with an increased antioxidant defense. Therefore, such an approach may be a good option for establishing a pre-IVM system.

A 5-year-old Holstein cow was referred to the Veterinary Medicine Hospital, Urmia University, Urmia, Iran, with abnormal estrous cycle. At rectal palpation, the unilateral ovary enlargement was detected. On transrectal ultrasonography view, the left ovary had uniformly hyperechogenic areas. The affected ovary was removed by ovariectomy and sent for histopathological examination. Histopathological evaluation revealed fibroblastic cells producing collagen fibers and theca cells containing lipids. Based on histopathological features, diagnosis of fibrothecoma was confirmed. This case reports an extremely rare fibrothecoma in cow.

Semen cryopreservation might be influenced by sperm concentration. This study was conducted to investigate three different semen concentrations [100 (C100), 50 (C50), and 25 (C25) × 106 spermatozoa/mL] on freezability of bull semen.
On each collection day, four ejaculates were collected (a total of 24 ejaculates from four bulls), pooled and divided to three equal parts. Each part was diluted to reach to one of the above mentioned final semen concentration and then frozen. After thawing, sperm motility, apoptosis status and mitochondrial activity were assessed.
The results showed that C100 resulted in significantly higher total sperm motility compared to C50 and C25 groups. The percentage of live spermatozoa was significantly higher in C100 compared to C50 and C25 groups. Also, C25 resulted in significantly higher early and late apoptotic spermatozoa compared to C50 and C100 groups. The mitochondrial activity was significantly lower in C25 compared to C100 and C50 groups.
It seems that low sperm concentrations (as low as 50×106) may be less advantageous for cryopreservation.

Cumulus-oocyte complexes (COCs) from cows were matured under normal (38.5°C) and elevated temperatures (41°C) simulating heat stress and their maturation was assessed based on measurement of cumulus expansion in both groups. There was a significant reduction (P

Enrichment of cell suspension with germ cells prior to injection into recipient seminiferous tubules is of importance in spermatogonial stem cells (SSCs) transplantation. Knock-out serum replacement (KSR) has been reported to enhance the proliferation of murine SSCs and human embryonic stem cells. The aim of the present study was to investigate the effect of KSR versus fetal bovine serum (FBS) and their interaction on colonization of bovine SSCs in vitro. When FBS (10%) was replaced with KSR (10%), a significant increase in the colonization of SSCs and the expression of Thy1, as marker for enrichment of SSCs, was observed. It was revealed that the lesser proliferative effect of FBS as well as the greater proliferative impact of KSR on SSCs colonization were not irreversible as cells having been cultured with FBS (10%) for three days with low colonization showed high rate of colonization in response to KSR (10%) and cells having been cultured with KSR (10%) with high colonization experienced low rate of colonization in response to FBS (10%). Further, it was shown that FBS did not contain factors inhibiting SSCs colonization and it simply lacked factors essential for SSCs proliferation because the combination of FBS (5%) and KSR (5%) resulted in even greater rate of colonization than did KSR (10%). In conclusion, the present study showed that addition of KSR to culture medium would significantly increase SSCs proliferation.

The receptors 1 and 2 of fibroblast growth factor (FGFR1 and FGFR2, respectively) have been observed in all types of testicular cells. Culture on extracellular matrix (ECM) has been observed to lead to initiation of differentiation in spermatogonial stem cells (SSCs). The present study was carried out to investigate whether FGFR1 and FGFR2 play a role in SSCs differentiation. Following isolation, bovine testicular cells were cultured on ECM-coated or uncoated (control) plates for 12 days. The gene expression of THY1, cKIT, FGFR1 and FGFR2 was evaluated using quantitative real-time polymerase chain reaction (PCR). Results related to the gene expression of markers of with undifferentiated (THY1) and differentiated (cKIT) spermatogonia implicated stimulation of self-renewal and differentiation in cells cultured on ECM-coated and uncoated plates, respectively (p 0.05). As a result, the gene expression of FGFR2 was greater in the ECM than control group (p 0.05). In conclusion, the present study revealed the potential role of FGFR2 in differentiation of SSCs during culture on ECM.

In the present study، the fertilizing potential of semen recovered from slaughtered bulls epididymis was evaluated after cryopreservation، by conventional techniques and flow cytometry methods. The cauda epididymal was dissected and sperm were recovered and evaluated for volume، sperm concentration، and membrane and acrosome integrity using a flow cytometer. Sperm fertility potential was tested by in vitro fertilization (IVF). For each bull، three trials of IVF were performed. Before freezing، on average، the sperm concentration was 216 ± 27. 5 × 106 sperm/ml. Sperm viability averaged 86. 5 ± 4%. The mean percentage of sperm with intact plasma membrane and acrosome before and after cryopreservation was 90. 7 ± 2. 9% and 90. 8 ± 1. 9% (P≥0. 05)، respectively. The fertilization rate using frozen/thawed epididymal semen averaged 64. 1 ± 3. 9% fertilization with no significant differences between bulls (P>0. 05). For the bull considered as control، the fertilization rate was 72. 2 ± 4. 5%، differing significantly (P>0. 05) from the frozen/thawed epididymal semen’s fertilization rate. In conclusion، it is possible to use in vitro techniques with cryopreserved spermatozoa obtained from bull’s epididymis using a controlled rate freezing method with a predetermined freezing curve، and with assessment of sperm’s viability by conventional techniques and flow cytometry methods، together with the fertilizing ability of cryopreserved epididymal spermatozoa.