Iranian journal of veterinary research最新文献

Background: Conformation traits (CNTs) are part of the selection goals that significantly affect cow economic efficiency, health, welfare, and productive life in the dairy industry.

Aims: This study focused on a genome-wide association study (GWAS) and genetic parameters estimation for 21 CNTs, including udder, leg-foot, body, type, and final classification traits in the Turkish Holstein (THol) dairy cattle population.

Methods: A restricted maximum likelihood with a univariate model including the fixed effects of herd-year-season and days in milk was used. The total dataset consisted of CNTs records and Affymetrix BovineSNP54K data for 3,008 THol cows that calved from 2019 to 2022. The gene ontology and Kyoto Encyclopedia of genes and genome pathway databases were used to assign genes to functional categories. The biological pathways were performed in BioMart databases.

Results: The heritability of these 21 CNTs ranged from 0.01 (udder index) to 0.133 (udder depth). A total of 16 significant single nucleotide polymorphisms (SNP) associated with 13 CNTs was identified. Significant SNP overlap in the candidate genes, which include ITGB1, TNN, and SEMA3D, have potential for researchers and breeders for CNTs in cattle breeding.

Conclusion: These results provide valuable knowledge and contribute to the elucidation of the genetic factors responsible for conformation traits in dairy cattle populations.

Background: Escherichia coli is not naturally present in fish microbiota but can be acquired from sewage-contaminated aquatic environments.

Aims: This study was performed to isolate and characterize the E. coli strains in rainbow trout fish marketed for human consumption.

Methods: A total number of 166 fish were randomly collected from different retail settings in Kerman, Iran. The fish samples were analyzed to detect E. coli isolates. Antimicrobial resistance genes, Shiga toxin virulence subtypes and phylogenetic sequences were screened by PCR.

Results: Prevalence of E. coli isolates on the skin, in the gills and intestine were 76.5% (127/166), 6.6% (11/166), and 3% (5/166), respectively. The most prevalent antimicrobial resistance phenotypes were observed against florfenicol (86.61%), erythromycin (83.46%), flumequine (82.67%), and oxytetracycline (81.88%); and 98.42% of the isolates were multi-drug resistant. The most frequent resistance gene was bla _TEM (14.17%), followed by qnrA (10.23%), tetB (9.44%), sul2 (8.66%), bla _SHV (7.87%), sul1 (7.87%), dhfr1 (3.93%), bla _{CTX -M} (3.14%), dhfrV (1.57%), bla _OXA (0.78%). Totally, 8.66% of isolates were categorized into three pathotypes including STEC, EPEC and EHEC. The stx subtypes including stx1a, stx1c, stx1d, stx2c, stx2d, stx2e and stx2f were identified in stx-positive strains. The E. coli isolates were classified into five phylogenetic groups including A (23.62%), B2 (3.93%), D (2.36%), F (9.44%) and cryptic clade I (11.81%).

Conclusion: The study revealed that the skin of retail rainbow trout marketed in Kerman may be one of the potential passive carriers of multi-drug resistant and virulent E. coli strains.

Background: Gestational nutrition, particularly in organic dairy goat farming, where natural feeding is mandatory for early gestation, plays a crucial role in determining the health of farm animal offspring. Omega-3 fatty acids are important for extending gestation periods, enhancing neonatal vitality, and increasing birth weights, primarily through their positive impact on colostrum composition.

Aims: This study focused on the potential benefits of omega-3 fatty acids for developing passive immunity in offspring.

Methods: Sixty-nine pregnant German Fawn x Hair crossbred does were divided into two groups. One group received fish oil (group F, n=35) and the other rumen protected fat (RPF) (group P, n=34) during the first half of gestation. In the second half of gestation, these groups were further split: group FF (n=16) continued on fish oil, while group FP (n=19) switched to RPF; group PP (n=17) remained on RPF, and group PF (n=17) switched to fish oil. Blood was collected from 60 kids at various times post-birth to measure immune factors. Immunoglobulins were quantified using the ELISA method, while biochemical parameters were assessed spectrophotometrically.

Results: The PF and PP groups showed significantly higher IgA levels (P<0.05). The PF group also had a significant increase in total protein (P<0.05).

Conclusion: The dietary strategy in our study did not positively influence passive immune transfer. Further research is needed to determine the optimal dosage and timing of these supplements to maximize benefits.

Background: Coeliotomy in chelonian species is performed to gain access to the abdominal cavity and requires general anesthesia. In reptile medicine, alfaxalone and propofol are often preferred, although the usage of these drugs is limited by cost and/or vascular access. Furthermore, according to a recent study, propofol produces significant oxidative stress in red-eared sliders (Trachemys scripta elegans), and in such cases, a ketamine and medetomidine combination may provide a better choice.

Case description: Three owned red-eared sliders were separately presented with a history of recent lethargy, inappetence, dyspnea, and restlessness.

Findings/treatment and outcome: In these three cases of chronic dystocia, a ketamine and medetomidine combination was used to achieve anesthesia induction for surgical treatment. Additionally, intrathecal administration of lidocaine was performed to achieve a potential analgesic effect in deeper intracoelomic reproductive organs. Preoperative changes in blood parameters were observed in one animal, suggesting abnormal kidney function. The same animal showed signs of resedation postoperatively, prolonged recovery, and had a fatal outcome 48 h after the surgery with signs of kidney damage in histopathological evaluation. In the recovery period, none of the surviving animals (n=2) showed neurological or respiratory complications that could be associated with subcarapacial sinus anesthesia administration or intrathecal local anesthesia.

Conclusion: According to our observations, intrathecal lidocaine administration provided sufficient analgesia during prefemoral coeliotomy and reproductive organ manipulation. These modes of anesthesia in chelonians require further investigation.

Background: Listeriosis is a disease that occurs in immunocompromised people, caused by a zoonotic bacterium, Listeria monocytogenes. The significance of its prevalence in raw meat lies in its potential to cause illness if the meat is undercooked, fails to reach the recommended internal temperature, or through cross-contamination.

Aims: This study aims to assess the presence of L. monocytogenes in fresh chicken, fish, and frozen/ready-to-eat (RTE) meat sourced from the retail markets of two major cities in Pakistan.

Methods: The identification was done by biochemical and molecular methods targeting two genes of Listeria Pathogenicity Island (LIP-1) i.e., prfa and hly genes by PCR and was sequence analyzed, isolates sequences were submitted to NCBI GenBank to get accession number (ON859912, ON933793, ON933794, ON933795, ON933790, ON933791, and ON933792). The antibiotic resistance of these isolates was confirmed against seven antibiotics using the Disk Diffusion Method.

Results: The antibiotic susceptibility profile of these isolates shows that most of the isolates were resistant to Vancomycin (43.2%), Gentamycin (37.8%), and Erythromycin (18.9%).

Conclusion: The study reveals a significant presence of L. monocytogenes in meat samples, accompanied by antibiotic resistance to commonly used antibiotics for listeriosis in Pakistan. This alarming situation poses serious hazards to public health.

Background: Johne's disease, a chronic wasting diarrheal illness, affecting ruminants, poses diagnostic challenges due to the prolonged incubation period of the agent.

Aims: The present study aimed to assess the efficacy of the IS900 PCR protocol, for detecting the causative agent and identifying predominant Mycobacterium avium paratuberculosis (MAP) genotypes circulating among small ruminants in the Punjab (India) through the application of IS1311 PCR-RFLP using milk samples.

Methods: A total of 205 milk samples, comprising 102 from goats and 103 from sheep, were tested for MAP DNA through IS900 PCR. Samples positive in IS900 PCR assay were subjected to IS1311 PCR assay, using M56 and M119 primers, followed by digestion of the products using Hinf I and Mse I restriction endonuclease enzymes.

Results: Of the 205 samples, 37 (16 sheep and 21 goats) tested positive. The IS1311 RFLP analysis of all positive samples exhibited a restriction pattern (67, 218, and 323 bp) corresponding to the Bison type MAP Strain.

Conclusion: Identification of a single predominant RFLP type (Bison) in both sheep and goats underscores the potential interspecies transmission and endemic co-circulation of Bison type MAP. These findings emphasize the need for further studies at regional and national levels, offering valuable insights for the development of comprehensive, monitoring and surveillance programs.

Background: Sperm retrieval methods and surgical interventions are typically performed with the aid of anesthetic agents. In cases where the depth of anesthesia is insufficient, the procedure is often repeated.

Aims: This study aimed to investigate the effects of repeated administration of xylazine-ketamine (XK) and medetomidine-ketamine (MK), as commonly used agents in laboratory animals, on sperm parameters, reproductive hormones, and testicular oxidative stress status.

Methods: A total of 60 rats were used in the study. The animals were divided to two groups of thirty animals each as XK or MK groups, then each group was further divided into five subgroups (control, single dose, 1 repeat, 2 repeats, 3 repeats). Results: In the MK application group, the 2 repeats group exhibited a significant decrease in motility (P<0.001), an increase in the percent of abnormal sperms (P<0.05), and an elevated dead-to-live sperm ratio (P<0.001). In the MK 3 repeats group, a decrease in testosterone levels was observed (P<0.001). In all application groups (XK and MK), mRNA levels of testicular catalase (CAT), superoxide dismutase 1 (SOD1), androgen receptor (AR), and caspases 3/8/9 were significantly reduced (P<0.001).

Conclusion: Despite the adverse effects of repeated anesthesia on certain testicular parameters, this study revealed that XK application is safer than MK in terms of spermatological characteristics.

In the era of antibiotic resistance, where multidrug-resistant (MDR), extensively drug resistant (XDR), and pan-drug resistant (PDR) Gram-negative infections are prevalent, it is crucial to identify the primary sources of antibiotic resistance, understand resistant mechanisms, and develop strategies to combat these mechanisms. The emergence of resistance to last-resort antibiotics like colistin has sparked a war between humanity and resistant bacteria, leaving humanity struggling to find effective countermeasures. Although colistin is used as a highly toxic antibiotic in infections that are not treated with routine antibiotics, its widespread use in animal breeding and veterinary medicine has contributed to the spread of colistin-resistant bacteria, plasmid-borne colistin resistance genes (mcr), and antibiotic residues in livestock and animal-derived foods. These sources can potentially transmit colistin resistance to humans through various routes. Therefore, managing the use of colistin in livestock and animal foods, implementing strict monitoring, and establishing guidelines for its proper use are essential to prevent the escalation of colistin resistance. This review article discusses the latest mechanisms of colistin antibiotic resistance, particularly biofilm production as a public health threat, the livestock and animal food sources of this resistance, and the routes of transmission to humans.

Background: A serious community concern worldwide is the alarming spread of enterobacteria producing extended-spectrum beta-lactamase (ESBL) enzymes. The food-producing animals harbor ESBL-producing enterobacterales and disseminate these resistant strains of pathogens through faeces. ESBL producers are multidrug-resistant phenotype posing a challenge to the disease management in clinical settings.

Aims: The objective of the present study was to investigate the prevalence of ESBL-producing Escherichia coli, and Klebsiella pneumoniae from fecal samples (n=340) of healthy (n=300) and diarrhoeic (n=40) sheep and goats and hand swabs (n=70) of animal handlers.

Methods: Presumptive ESBL producing bacteria were identified using ESBL agar, which were then confirmed by combined disc method (CDM). Genotypic detection of beta-lactamase, quinolones and tetracycline resistance genes was done using PCR.

Results: A total of 156 enteropathogenic E. coli were recovered from sheep (79/170) and goats (77/170). Phenotypic antimicrobial resistance data revealed high resistance against cefazolin with 91.13% and 84.41% in sheep and goats, respectively. Low resistance was recorded against carbapenems. All the ESBL producing isolates revealed a multiple antibiotic resistance (MAR) index >0.2. The predominant β-lactamase gene found was the blaTEM detected in 110 (70.51%) isolates followed by blaCTXM in 80 (51.28%) isolates.

Conclusion: The findings of the present study revealed a high prevalence of multidrug resistance E. coli and K. pneumoniae in food-producing animals. It represents an issue of concern and requires serious need for implementing effective approaches to reduce multidrug resistance in commensal organisms.

Background: Leptospirosis is a zoonosis with a large distribution in the globe, and Leptospira spp. is responsible for the disease. Mammalians can serve as reservoir hosts of the bacteria; however, rodents, particularly rats, are known to be the most important reservoir, principally, for Leptospira interrogans serovar Icterohaemorrhagiae. In Algeria, few data are available concerning the circulation of the Leptospira bacterium in human and in animals including rodents.

Aims: Our study aimed to bring to light the importance of rats as reservoir host of Leptospira spp. in the city of Blida, Algeria.

Methods: A total of 100 rats including 88 Rattus norvegicus and 12 Rattus rattus were captured, their serums were tested for antibodies by Microscopique Agglutination Test (MAT), and their kidneys and livers were subjected to culture in Ellinghausen, McCullough, Johnson and Harris (EMJH) medium.

Results: Our study revealed a sero-prevalence of 43% (95% CI: 33.3-52.7%), the most common infecting serogroup was Icterohaemorrhagiae 11% (11/100), and the highest titer was register for the serogroup Canicola 1:2560. No statistical difference was recorded between the two sexes, the classes of age, and the rat's species; However, rats captured in urban area seemed to be more infected than those captured in rural area. Organs culture confirmed the carrying status of the bacteria with prevalence of 8%.

Conclusion: Our survey confirms the role of rat as reservoir host of Leptospira, and provides valuable data on the epidemiology of leptospirosis in this animal. Therefore, rat population control in the city of Blida is important to prevent outbreaks of leptospirosis in human and in other animals.