Iranian journal of veterinary research最新文献

Background: Assisted reproduction techniques in birds have contributed to many species' conservation and sustainable use. One of these techniques is semen cryopreservation, which is possible following the discovery of suitable cryoprotectants.

Aims: This study aimed to characterize the fresh and post-thaw ejaculates of different species of birds of prey.

Methods: The following species were included in the study: red-tailed hawk (Buteo jamaicensis) n=3, golden eagle (Aquila chrysaetos) n=3, and Harris's hawk (Parabuteo unicinctus) n=3. Twenty-five ejaculates were obtained for each species. The percentage of spermatozoa motility, viability, and morphology were evaluated.

Results: Evident differences were observed among the ejaculates of the three species, particularly in sperm length and between the fresh and post-thaw parameters of the same species in which the motility reduced to approximately 40% after thawing. It was demonstrated that sperm cryopreservation of the studied species was possible using the same freezing protocol.

Conclusion: This study showed that sperm characteristics could influence the parameters obtained during their in vitro conservation, both in the fresh and post-thaw states.

Background: Estrus synchronization is an important assisted reproductive technology to improve the reproductive performance in ewes. Various protocols have been used with variable success rates, however; literature regarding field applicable estrus synchronization is meagre.

Aims: The present study was designed with the aim to evaluate the estrus synchronization protocols on reproductive performance in ewes using different hormones.

Methods: Experimental ewes were divided randomly into three groups (n=15). Ewes of all groups received intravaginal sponge for 12 days. Subsequently, NP₄-GnRH and NP₄-eCG groups received 8 µg of buserelin acetate or 200 IU of eCG intramuscularly, respectively on day 12 whereas NP₄-Insulin group received insulin 0.2 IU/kg body weight subcutaneously for three consecutive days started on the day of sponge removal. Estrus detection commenced 24 h after sponge removal in NP₄-GnRH and NP₄-eCG groups and 24 h following last injection of insulin in NP₄-Insulin group. The ewes in estrus were separated and pen mated. The conception rate was determined by ultrasonography.

Results: The estrus response and conception rates were 71.43, 92.86 and 53.85%, and 70.00, 84.61, and 71.43%, respectively in NP₄-GnRH, NP₄-eCG, and NP₄-Insulin groups. The lambing rates were the same as the conception rates. The single and multiple birth rates were 71.41, 36.36 and 60.0%, and 28.57, 63.64, and 40.0% whereas prolificacy was 128.57, 190.91, and 140.00%, respectively in NP₄-GnRH, NP₄-eCG, and NP₄-Insulin groups.

Conclusion: In conclusion, the estrus synchronization protocol including intravaginal progesterone sponge and eCG was found to be more effective under field conditions.

Background: Mesenchymal stem cell (MSC) therapy has ameliorative effects for treating knee osteoarthritis (KOA) disease. Moreover, there is a growing interest in using MSCs-derived secretome (Sec) containing trophic factors secreted by MSCs for KOA treatment. Recently, some studies have suggested that the combination of MSCs and Sec has the potential to treat the diseases.

Aims: This study aimed to evaluate the ameliorative effects of combined administration of infrapatellar fat pad (IPFP)-derived MSCs, a type of adipose-derived stem cells (ASCs), for treating degenerated cartilage in a rat model of KOA.

Methods: IPFP-ASCs were isolated from the IPFP of male rats. Sec was obtained from IPFP-ASCs in the fourth passage. Eight weeks after the induction of KOA by collagenase II, the rats were divided into 5 groups (n=5), including a control group with no treatment, and four experimental groups that received sodium hyaluronate (Hyalgan^®, Hya), ASCs, Sec, and IPFP-ASCs+Sec, respectively by an infrapatellar injection. To perform the pathological and radiological evaluations, the animals were sacrificed 8 weeks later.

Results: Our findings indicated that combined administration of the IPFP-ASCs and Sec statistically (P<0.05) improved scores of medial tibial and femoral condyles and medial fabella osteophytes. Also, it statistically (P<0.05) enhances the cartilage surface, matrix, cell distribution and population viability, and subchondral bone indices. No statistical difference was observed between IPFP-ASCs+Sec and IPFP-ASCs.

Conclusion: Administration of IPFP-ASCs+Sec has a therapeutic potential to treat KOA in rats. However, there is no difference in the combined administration of IPFP-ASCs and Sec with IPFP-ASCs alone.

Background: Oxidative stress damages biological molecules and plays a role in aging-related cardiovascular diseases. Cinnamomum zeylanicum is a major source of antioxidants that may work against age-related cardiovascular changes.

Aims: This study aimed to assess the changes in electrocardiography and lipid profile as well as indicators of the oxidant-antioxidant system with advanced age in rats. Also, the possible beneficial effect of cinnamon on these parameters has been investigated.

Methods: In this experimental study, thirty male Sprague-Dawley rats were randomly assigned to five groups. The control groups of 12, and 20 months received a normal chow diet, while the investigation group was given a control diet mixed with cinnamon powder (1% of the diet). Also, a control group of 3-month-old rats was considered for assessment of age effects. Systolic blood pressure (SBP), ECG, serum lipid profiles, and heart oxidative stress markers were compared in different groups at the end of the study.

Results: Systolic BP, serum cholesterol, HDL and LDL-cholesterol, the heart level of malondialdehyde (MDA) and nitric oxide metabolites (NOx), the ECG parameters including QRS duration, PR, T_peak-T_end, and QT interval, as well as QTc increased significantly in older rats (20 months vs 3 months). Cinnamon consumption restored MDA levels, QRS duration, and T_peak-T_end interval in aging hearts. Whereas, neither aging nor cinnamon consumption could affect SOD activity.

Conclusion: The results demonstrated that aging is associated with ECG alteration, oxidative stress, and an increase in TC, LDL, and HDL cholesterol. Cinnamon improved electrical heart activity in aged rats (20 months) by restoration of QRS duration and T_peak-T_end interval as well as amelioration of heart oxidative stress. Altogether, cinnamon supplementation has a cardioprotective effects during aging in rats.

Background: Necrotic enteritis (NE) is an economically important disease, caused by Clostridium perfringens type G strains, and is one of the major targets of antibiotics used in poultry feed.

Aims: This study aimed to genotypically characterize virulent strains of C. perfringens isolated from healthy and diseased birds in Iran.

Methods: Eleven isolates were derived from necrotic enteritis cases, and 27 were from healthy chickens. Isolations were performed using blood agar. To assess whether zmp is generally associated with avian NE, 38 C. perfringens isolates were screened using PCR and western blotting. The involvement of these toxins as virulence factors was investigated using cytotoxicity assays.

Results: All isolates carried the phospholipase c (plc) gene regardless of their origin and virulence. The zinc metallopeptidase (zmp) gene was found in the isolates collected from birds affected by necrotic enteritis. Furthermore, Necrotic enteritis like B (NetB) was only found in 36.36% of the isolates derived from necrotic enteritis-infected birds. Western blot analysis further confirmed the expression of Alpha toxin, NetB, and Zmp in different isolates. Incubation of Leghorn Male Hepatoma (LMH) cells with crude C. perfringens toxins indicated that the supernatants of all bacterial strains were toxic toward LMH cells at different dilutions. In addition, crude toxins of the Cp28 strain expressing Alpha toxin, Zmp, and NetB showed an approximately 50% cytotoxic dose (CD50) at a 1:34 dilution. Strain Cp119.2, which produces both ZMP and the Alpha toxin, and strain Cp48, which only produces the Alpha toxin, showed CD50 at 1:23 and 1:4 dilutions, respectively.

Conclusion: It seems that both NetB and Zmp play major roles in the cytotoxicity and pathogenicity of this organism.

Background: Antimicrobial resistance in avian pathogenic Escherichia coli (APEC) represents a major concern in the avian industry worldwide and limited studies have investigated Colistin resistance among APEC in Algeria.

Aims: Investigate antibiotic resistance, in particular, Colistin, and mediated-Colistin resistance (mcr) genes, as well as the virulence genes in APEC.

Methods: One hundred E. coli were isolated from poultry suspected of colibacillosis. Antimicrobial susceptibility testing was done on 14 antibiotics by the disk diffusion method. Colistin minimum inhibitory concentration (MIC) was assessed by the broth microdilution method. Using multiplex PCR, mcr genes (mcr-1 to 5) and 7 virulence-related genes were investigated in Colistin-resistant isolates.

Results: Results showed high resistance to Tetracycline (99%), Nalidixic acid (92%), Doxycycline (90%), Ampicillin (89%), Ofloxacin (74%), Sulfamethoxazole-Trimethoprim (72%), and Amoxicillin-Clavulanic acid (57%); in addition, 92% of isolates were multidrug resistant. The rate of resistance to Colistin was 27% (27/100) of which 96.3% (26/27) of isolates carried the mcr-1 gene. Twenty-five of the Colistin-resistant isolates (92.59%) had at least three virulence genes. The most frequently isolated virulence genes were: fim H (96.3%) followed by hlyF, iroN, and iss (77.7%, each), iutA and ompT were found in 59.25% and 55.5% of isolates, respectively. The most prevalent combination of virulence factors was hlyF-iss-iroN-iutA-ompT-fimH.

Conclusion: This is the first report which highlighted Colistin resistance with the detection of mcr-1 in APEC isolates in the area of study. Colistin resistance and carriage of mcr-1 in virulent and multidrug-resistant isolates of E. coli are alarming and a surveillance program to limit the spread of these pathogens is mandatory.

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

Aims: 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.

Methods: 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.

Results: 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.

Conclusion: 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.

Background: Dromedary camels (Camelus dromedarius) are raised in extremely strict ecological conditions of deserts. Camels are vulnerable to many zoonotic infections. There are limited data on the occurrence of Q fever and borreliosis in camels, in Iran.

Aims: The current study was focused on the occurrence of Coxiella burnetii and Borrelia spp. infection in the blood samples of Iranian camels using molecular assays. Effect of the presence of these infections on various hematological factors and some acute-phase proteins (Hp, a1AGP, SAA) were also investigated.

Methods: Blood samples were collected from 113 clinically healthy camels to investigate the presence of the infections using nested PCR. Moreover, the sequence of positive samples was analyzed phylogenetically. Routine haematological tests were performed and the concentrations of acute-phase proteins were measured in serum using enzyme immunoassay.

Results: PCR result showed that 6.19% (95% CI: 2.53-12.35%) (7/113) of camels were positive for C. burnetii. In addition, sequencing results of the corresponding gene of the outer membrane protein (com1) revealed two different genotypes of C. burnetii agent in camels from Southern Iran. In the PCR assay, Borrelia spp. DNA was not detected in the samples. No significant difference was observed in hematological parameters or acute-phase proteins between positive and negative Q fever camels except for mean corpuscular hemoglobin (MCH) and red cell distribution width (RDW).

Conclusion: Clinically healthy camels might be very important reservoirs of zoonotic pathogens. Q fever is not considered a notifiable disease in camels of Iran, and clinical cases may scarcely be recognized by the healthcare system. Due to a lack of adequate information, additional studies on the molecular epidemiology and clinical pathology aspects of C. burnetii infection in Iran are needed.

Background: The increasing importance of antibiotic resistance shows the need for determining indices of the epidemiology of infection.

Aims: This study aimed to determine the virulence genes and antibiotic resistance profiles of Staphylococcus aureus isolated from bovine mastitis cases.

Methods: A total of 200 cattle were selected based on California Mastitis Test (CMT) results, and the samples were cultured in the laboratory. Grown colonies were examined by conventional phenotypic methods and confirmed using PCR amplification of 16S rRNA gene. The prevalence of the virulence genes was also defined. The results of phenotypic and molecular tests were compared using SPSS software by McNemar test. Then, the confirmed isolates were tested for antibiotic susceptibility using the disc diffusion method.

Results: Of the 200 positive CMT cattle, 24 animals were positive for S. aureus and confirmed using 16S rRNA gene amplification. Statistical analysis showed that the phenotypic and genotypic tests of hemolysin genes were not significantly different (P>0.01). PCR analysis revealed the presence of coa and clfa genes in more than half of the cases. Overall, nine genetic profiles of virulence factors were found among S. aureus isolates. The highest and lowest resistance rates were against penicillin and gentamicin, respectively.

Conclusion: Our findings showed a high rate of antibiotic resistance. So, accurate and fast diagnosis and antimicrobial susceptibility tests should be considered before prescribing the drugs.