Iranian Journal of Veterinary Research
Volume:24 Issue: 3, Summer 2023

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.

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.

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.

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).

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.

Vancomycin resistance encoded by the vanA/B/M genes in enterococci is clinically important because of the transmission of these genes between bacteria. While vancomycin resistance is determined by detecting only vanA and vanB genes by routine analyses, failure to detect vanM resistance causes vancomycin resistance to be overlooked, and clinically appropriate treatment cannot be provided.

The study aimed to examine the presence of vanM-positive enterococcal isolates in Ankara, Turkey, and to have detailed information about them with sequence analyses.

Caecal samples were collected from sheep and cattle during slaughter at different slaughterhouses in Ankara, Turkey. Enterococci isolates were identified, confirmed, and analyzed for the presence of vanA/B/M genes. Antibiotic resistance profiles of isolates were determined by the broth microdilution method. A whole genome sequence analysis of the isolates harboring the vanM and vanB genes was performed.

13.7% of enterococcal isolates were determined as Enterococcus faecium and Enterococcus faecalis. 15% of these isolates contained vanB, and 40% were vanM-positive. S98b and C32 isolates were determined to contain 16 CRISPR-Cas elements. 80% of the enterococci isolates were resistant to nitrofurantoin and 15% to ciprofloxacin. The first vanM-positive vancomycin-variable enterococci (VVE) isolates from food-producing animals were identified, and the S98b strain has been assigned to Genbank with the accession number CP104083.1.

Therefore, new studies are needed to facilitate the identification of vanM-resistant enterococci and VVE strains.

Biofilm production by Staphylococcus aureus is a prevailing cause of multidrug resistance. The evolutionary mechanisms of adaption with host and pathogenicity are poorly understood.

The present study aimed to investigate the biofilm-forming potential, associated multidrug resistance, and the evolutionary analysis of S. aureus isolated from bovine subclinical mastitis.

122 S. aureus isolates were subjected to Congo red agar method (CRA), microtitre plate method (MTP), and PCR to check the biofilm-forming potential. The Kirby-Bauer disk diffusion method was used to evaluate the antibiotic resistance pattern. The icaA gene of isolates was subjected to molecular and evolutionary analysis using different bioinformatics tools.

The results showed that 63.93% of S. aureus isolates carried the icaA gene and the detection rate of CRA was higher (36.07%) compared to the MTP test (24.59%). A total of 78.21% and 56.41% of biofilm-positive isolates were methicillin-resistant S. aureus (MRSA) and vancomycin-resistant S. aureus (VRSA), respectively. All S. aureus isolates (100%) showed multidrug resistance. The molecular analysis showed an evolutionary link between isolates and revealed a strong codon bias, three different recombination events, and positive selection in some residues of the semi-conserved segments of the icaA gene.

The study concluded that biofilm-positive isolates have a high tendency to exhibit methicillin, vancomycin, and multidrug resistance. The findings suggest that mutation and selection are the most likely causes of codon bias in the icaA gene sequences. The variations led by recombination events and positive selection are suggestive of bacterial strategy to combat antimicrobial effects and to escape the host’s immune surveillance.

Infectious bronchitis virus (IBV), Newcastle disease virus (NDV), and avian influenza virus (AIV) H9N2 are major viral pathogens in broiler respiratory disease.

Following a respiratory disease outbreak and economic losses in eastern Iran 2020-2021, we investigated the role of major viral pathogens and the implemented vaccination programs.

Thirty-six respiratory disease affected broiler flocks in South Khorasan province were sampled, molecularly tested, and coinfections were investigated. The vaccination programs were obtained and the detected IBV were genotyped.

IBV, virulent NDV, and AIV H9N2 were detected in twenty-five, seven, and seven flocks, respectively. IBV+AIV, IBV+NDV, and NDV+AIV coinfections were respectively detected in six, five, and one flocks. Most IBV infected flocks (84%) had been immunized with a live IBV-Mass vaccine. All NDV infected flocks and 14.2% of AIV infected flocks had been vaccinated. IBV genotyping showed a high prevalence of variant 2 (83.3%), followed by Mass-type (12.5%), and Q1-type (4.2%). Variant 2 IB viruses were widely distributed in the province and half of them were mostly similar to the ones that had been detected in northern neighboring province, Khorasan Razavi.

Single infection with variant 2 IBV was a major cause of the respiratory disease outbreak in which use of the Mass vaccine was probably not effective. The high coverage and multiple doses of vaccination against Newcastle disease possibly had reduced the prevalence of NDV. Considering the regional origin of IBV strains, strong biosecurity measures should be implemented and vaccination programs using appropriate vaccine strains should be used.

Methicillin-resistant Staphylococcus aureus (MRSA), affecting livestock and human beings, has become a global public health hazard with economic consequences.

The current study was designed to investigate the prevailing MRSA-associated subclinical mastitis and associated risk factors in dairy buffaloes. The study also highlighted the genetic variations and in silico-based proteomic differences among MRSA isolates.

Out of 516 milk samples, 45.93% (237/516) were found positive for subclinical mastitis, while the prevalence of S. aureus was recorded 56.12%. The methicillin resistance in S. aureus isolates was evaluated by oxacillin disc diffusion test and molecular identification of the mecA gene.

The results revealed a phenotypic and molecular prevalence of MRSA at 45.11% and 18.79%, respectively. The risk factor analysis revealed that among various assumed risk factors, parity, milking hygiene, milker care during milking, milk yield, housing system, and floor type were significantly associated with subclinical mastitis in buffaloes. The sequencing and phylogenetic analysis showed no significant genetic variations among study isolates and depicted a high similarity with isolates from Africa, USA, India, Italy, Turkey, and Iran. The in-silico protein analysis showed that all sequences had the same protein motifs resembling penicillin protein 2a except Buff-13, whose protein structure resembles alpha-catenin-like protein hmp-1.

The current study was the first report of the genotypic characterization and in silico protein analysis of MRSA from dairy buffaloes in Pakistan. The result highlighted the importance of antimicrobial resistance (AMR) and development of control strategies against MRSA infections.

Precise and on-time diagnosis of the udder’s diseases is important, because of their economic importance. Udder structures like teat, parenchyma, and supramammary lymph nodes can be evaluated by ultrasonography.

The study aimed to evaluate the ultrasonographic technique for imaging the supramammary lymph nodes and udder’s tissue in Saanen goats and the relation between the findings of ultrasonography and subclinical mastitis.

Thirty milking Saanen goats were evaluated in the study. Milk sampling from each teat was performed under standard conditions for bacteriological culture and somatic cell count (SCC). A 7.5 MHz linear transducer was used for the ultrasonography of teats with the water bath technique, and supramammary lymph nodes and udder’s tissues were imaged using a 10 MHz linear transducer with direct contact. The length, height, area, and echogenicity of each lymph node and the teat canal wall diameter were measured using ImageJ 1.47v on the ultrasonography scanned images and analyzed by SPSS software.

There was no significant relationship between the dimension of the supramammary lymph nodes and SCC or culture. Age had a positive relationship with lymph node size. No significant relationship was seen between the size of the supramammary lymph node before and after the treatment. Supramammary lymph nodes’ echogenicity of the quarter with subclinical mastitis and healthy ones represented no significant difference before and after the treatment.

Ultrasonography of the udder, teat, mammary gland, and supramammary lymph nodes is a safe and non-invasive method for visualizing separate structures. The positive relationship between SCC and milk echogenicity as well as supramammary lymph nodes dimension, and age was described.

Artificial insemination (AI) is one of the most important reproductive technologies used to modify animals genetically. Using this method, the genetic composition of the herd can be improved and selected by choosing bulls with excellent genetic characteristics. Taxifolin (TXF), a plant flavonoid, has shown an antioxidative effect.

The current study aimed to evaluate the impact of TXF on the quality of frozen-thawed semen in Fleckvieh (Simmental) dual-purpose bulls.

Freezable semen specimens were obtained by an artificial vagina. Ejaculates were equally divided into six parts for six experimental groups, including without adding TXF to diluent (C), adding 25 (T25), 50 (T50), 100 (T100), 200 (T200), and 400 (T400) μM TXF. Sperms were frozen in a one-step dilution method. Semen factors, including motility, viability, sperm membrane integrity, DNA damage, and oxidant and antioxidant enzyme activities, were examined after thawing.

Our findings revealed that all semen quality parameters, antioxidant enzyme activities, and free radical levels were superior in TXF-treated groups compared to the control group, and the differences were noticeably higher in the T100 group than the other groups.

Adding 100 μM TXF to diluent could improve the quality of bull frozen semen.

With the increasing use of cementless total hip arthroplasty (THA), stem subsidence has emerged as one of the primary complications. Although electron beam melting (EBM)-manufactured stems have been demonstrated to prevent subsidence, there has been limited investigation into the comparative biomechanical impact of collarless and collared EBM cementless stems on stem subsidence in veterinary medicine.

This study aimed to compare the stem implant resistance and failure mechanical properties between collarless and collared EBM-manufactured stems.

Seven pairs of femurs were harvested from canine cadavers. In each pair of femurs, the left femur was implanted with a collarless, and the right femur with a same-sized collared cementless stem. Specimen constructs were mounted to the loading frame of a testing machine and load was transferred to the femoral stem parallel to the longitudinal axis of the femur until the stem subsided 5 mm. Load and stem displacement data acquired during the tests were used to generate load-displacement curves and obtain stiffness, yield, and failure data for each specimen construct. Yield and failure energies were calculated as the areas under the load-displacement curves to the respective points. The effects of implant type and load during subsidence were analyzed using paired t-tests.

The yield and failure loads for the collared stems were approximately 40% greater than for the collarless stems (156.39 ± 43.63 kgf vs. 112.01 ± 59.83 kgf, P<0.05).

This study supported the advantages of collared EBM stems, including subsidence prevention and better initial stability for early osteointegration.

Tropical theileriosis is the most prevalent hemoprotozoan disease in Pakistan.

The study aimed to investigate the epidemiology and evolutionary relationship of Theileria annulata in bovines in diverse agro-climatic regions of Punjab, Pakistan.

800 blood specimens were collected from asymptomatic cattle (n=480) and buffaloes (n=320) using a multistage sampling method from Sargodha (n=400) and Multan (n=400) districts. The samples were assessed for blood smear microscopy and cytochrome b gene based PCR. Twenty samples were collected from each union council of each district.

The overall prevalence of T. annulata infection in bovines was 9% and 17.13% as determined by blood smear analysis and PCR, respectively. The disease positivity in cattle and buffaloes was respectively 10.21% and 20.42% by blood smear screening and 7.19%, 12.19% by PCR. The overall PCR based prevalence in the Sargodha and Multan districts was 19% and 15.25%, respectively. Absence of rural poultry, tick infestation, and a history of tick-borne diseases had significant effect in cattle. Tick infestation and age were the main statistically significant disease determinants in buffaloes. The evolutionary analysis of the cytochrome b gene showed that the Pakistani isolate infecting buffalo was related to those from Iran, India, Egypt, and Sudan. The isolate from cattle was genetically close to those from Pakistan, India, Iran, Iraq, and Turkey.

It can be concluded that biotic and abiotic factors contribute to disease occurrence. The current study will help to devise control strategies to prevent substantial economic losses.

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

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

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.

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.

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.

Optimal vitamin D levels for an effective role in immune function and rickets prevention are thought to vary, but have not yet been definitively determined. Reports on reference values of 25-hydroxyvitamin D (25(OH)D) in cats are limited.

The study provides information about serum 25(OH)D values in cats with different age, gender, breed, diet type, reproductive status, housing condition, and also the relationship between these levels and various hematological and biochemical parameters.

Clinically healthy cats (88) were included in the study. Physical examination and assessment of hematological and biochemical parameters were performed on cats in order to confirm their health status. Reference value of serum 25(OH)D was assayed by ELISA method and the effects of age (under six months and above six months), gender, breed, diet (only commercial diet, only homemade food, mixture of commercial and homemade food), reproduction status, and housing conditions on serum 25(OH)D was determined.

The median, 2.5% and 97.5% of 25(OH)D in sampled cats were 19.74 ng/ml, 3.12 ng/ml, and 92.1 ng/ml, respectively. Serum 25(OH)D concentration was lower when homemade diet was used compared to commercial and mixed diets as well as in cats under six months of age compared to older cats.

Diet type and age can affect serum 25(OH)D levels in healthy cats while other parameters had no significant effects.

Brucellosis is one of the most important zoonotic diseases caused by Gram-negative bacteria belonging to the genus Brucella. Detection of Brucella species in different countries is of utmost importance.

This study aimed to detect Brucella abortus and Brucella melitensis in domestic ruminant blood samples and their ticks in western Iran.

Sampling was conducted on ruminants from August to September 2020 in four different counties of Kurdistan Province, including Divandareh, Marivan, Baneh, and Sanandaj. Totally, 250 blood samples were collected from 250 small ruminants. There were no ticks on the skin of six (2.4%) ruminants, and 244 ticks were isolated from 244 animals. After genomic DNA extraction from all the collected samples, quantitative polymerase chain reaction (qPCR) was performed to detect IS711 gene.

Based on qPCR results, Brucella genus was detected in two blood samples (0.8%) from female sheep and four ticks (1.6%) from male sheep, including three Dermacentor marginatus (1.22%) and one Rhipicephalus turanicus (0.4%). Although B. melitensis was not detected in any tick or blood sample, one tick sample (D. marginatus) was positive for B. abortus.

Considering the positivity of ticks for brucellosis in this study, there is a possibility of Brucella transmission from infected ticks to humans and animals through tick bites, nevertheless, in order to identify the Brucella transmission relationship between ticks and animals, serological tests should be used in future studies.