Hasil untuk "Veterinary medicine"

Dapeng Li, Fuwei Li, Wei Liu et al.

Controlling low ambient temperatures and ammonia levels is critical for effective environmental management in poultry houses during winter, as both represent persistent stressors affecting bird health and productivity. However, evidence regarding their combined long-term effects on the physiological responses of laying hens remains limited. In this study, 576 eighteen-week-old Hy-Line Brown hens were randomly assigned to six treatments (8 replicates with 12 birds per replicate each treatment) and housed in environmentally controlled chambers for 20 weeks: T1 (8 °C, ≤5 ppm ammonia), T2 (8 °C, 20 ppm ammonia), T3 (8 °C, 45 ppm ammonia), T4 (20 °C, ≤5 ppm ammonia; control), T5 (20 °C, 20 ppm ammonia), and T6 (20 °C, 45 ppm ammonia). Plasma samples were collected at 22, 26, 30, 34, and 38 weeks to evaluate physiological stress biomarkers (corticosterone, CORT; total antioxidant capacity, T-AOC), immunoglobulins (IgG, IgM, and IgA), and reproductive hormones (luteinizing hormone, LH; follicle-stimulating hormone, FSH; estradiol, E2). At 38 weeks, hypothalamus, pituitary, and spleen tissues were collected to assess the relative mRNA expression of gonadotropin-releasing hormone (GnRH), FSH, tumor necrosis factor-α (TNF-α), and interleukins (IL-1β, IL-6, and IL-10). Results showed that both cold and ammonia stress reduced antioxidant capacity, disrupted immune homeostasis, and altered reproductive hormone profiles. Cold exposure induced acute immunoendocrine alterations with partial physiological adaptation over time, whereas ammonia exerted progressive and cumulative damage, including elevated immunoglobulins (IgG and IgM) and downregulation of GnRH and FSH expression. Combined exposure significantly upregulated TNF-α and IL-1β expression, suggesting a synergistic inflammatory response. These results highlight complex, parameter-specific interactions between cold and ammonia stressors, emphasizing the need for targeted environmental strategies. Stage-specific interventions—thermal regulation in early laying and ammonia control in later phases—are recommended to safeguard hen health and optimize productivity under winter conditions.

Maher Alnajjar, Zsófia Fekete, Tibor Nagy et al.

Allele-specific expression (ASE) reflects the unequal expression of the parental alleles and can imply functional variants in cis-regulatory elements. The conventional ASE detection methods often depend on the presence of heterozygous variants in transcripts or sequencing a large number of individuals, both of which are often limited. In this study, we present a family-based strategy for detecting ASE and potential cis-regulatory elements utilizing both RNA-seq and whole-genome sequencing (WGS) from a pedigree. Using a rabbit family consisting of two divergent parents and their eight offspring, we identified 913 ASE genes by analyzing inheritance patterns of gene expression levels. Expression was classified into three levels—high, medium, and low—and used to define seven distinct expression groups across the family (e.g., H_L: high in the mother, low in the father, and intermediate in the offspring). Many ASE genes lacked heterozygous exonic variants, and inference was achieved via RNA read count patterns. We also pinpointed conserved transcription factor binding sites (TFBS) with sequence variants showing similar inherited genotypic patterns (e.g., AAxBB), suggesting their regulatory roles as eQTLs. Differential gene expression (DEG) analysis between the parents highlighted some candidate genes related to meat production and quality traits. Our findings show that the family-based method using RNA-seq and WGS data is promising for exploring ASE and mapping possible eQTLs.

Choriyev Otabek, Dilmurodov Nasriddin, Babanazarov Eshmakhamad et al.

The characteristics of changes in the morphometric dimensions of the skin of horses belonging to the “Karabayir” breed at various physiological stages of postnatal ontogenesis were studied. It was found that the thickness of the skin of various anatomical points of the horse’s body increases rapidly in the 2-3 age stages of postnatal ontogenesis, and in old horses, this indicator decreases, the thickness of the skin of the legs increases in the distal direction in connection with the morphofunctional properties, and the skin elasticity decreases. In connection with the effect of mechanical friction on the skin, it is noted that it is thin in the inner part of the thigh, and the thickest in the soft heel of the hoof, as well as somewhat thick in the lower part of the body of horses, and the thinnest in the ventral part of the head, neck, withers and abdomen. Also, it was found that the dermis of the skin in young horses, the subcutaneous layer (subcutis) thickens in middle-aged horses, and the dermis and subcutaneous layer thins and the skin elasticity decreases in old horses.

Armelle Prudence Kouengoua Kouengoua, Yves Ledoux Tsissa, Nestor Denakpo Noudeke et al.

Background and Aim: Bovine tuberculosis (bTB) is a contagious and notifiable disease, which is prevalent in cattle populations of many countries and in several wildlife species worldwide. However, the role of wildlife in the transmission and/or maintenance of bTB at the human-wild animal-animal interface and the epidemiology of zoonotic disease are poorly understood in Cameroon, where many wildlife species exist. This study aimed to estimate the prevalence and zoonotic risk factors of bTB at the cattle-wildlife-human interface in the South and East regions of Cameroon. Materials and Methods: We conducted a descriptive cross-sectional study from May to October 2022 in the southern region (Vallée du Ntem and Dja et Lobo) and eastern region (Haut Nyong and Lom et Djérem) of Cameroon to determine risk factors for bTB in Zebu Bororo, Goudali, Ndama, and Simmental cattle breeds. A comparative intradermal tuberculin testing (CIDT) was performed on 160 cattle randomly selected from herds using the threshold recommended by the World Organization for Animal Health. An interviewee-administered questionnaire was used to gather epidemiological data on sociodemographics, interaction between cattle and wildlife, and awareness of zoonotic tuberculosis (TB) from 90 cattle professionals. The prevalence of bTB at the herd level and associated risk factors were estimated using multiple logistic regression models. Results: Based on the comparative intradermal tuberculin test (CIDT), the estimated prevalence of bTB in 160 cattle (Zebu Bororo, Goudali, Ndama, and Simmental) in South and East Cameroon was 6.8% (4.35%-9.41%) and 1.8% (0%-3.6%) for threshold values 3 mm and 4 mm, respectively. The prevalence obtained by simple intradermal tuberculin test (IDT) was 0.6% (0%-1.2%) for a threshold value 4 mm. Univariate analysis revealed three risk factors associated with bTB with significant odds ratios (OR; p = 0.05): herd size (OR = 4.88; 95% confidence interval [CI]: 1.24-32.56); cattle aged>10 years (OR = 0.17; 95% CI: 0.05-0.53); and victims of bTB organ seizure (OR = 0.015; 95% CI: 0.002-0.067). Multivariate analysis showed that being a cattle herder and contact between wildlife and livestock due to forage was significantly associated with bTB exposure (adjusted OR = 0.02; p = 0.001). Conclusion: Bovine TB is prevalent in cattle of the South and East Cameroon. Comparative IDT of cattle reared in the epidemiological and environmental context of the study areas yielded better results at a threshold of 3 mm than at a threshold of 4 mm recommended by the World Health Organization. Factors associated with exposure to/appearance of bTB were high herd size, cattle aged >10 years old, seizures of tuberculous organs, shepherding as a profession, and contact between cattle and wildlife can be due to lack of forage.

Nguyen Dinh-Hung, Samuel Mwakisha Mwamburi, Ha Thanh Dong et al.

This study aims to genomically elucidate six isolates of rapidly growing non-tuberculous mycobacteria (RGM) derived from Siamese fighting fish (<i>Betta splendens</i>). These isolates had previously undergone phenotypic and biochemical characterization, antibiotic susceptibility testing, and in vivo virulence assessment. Initial DNA barcoding using the 16S rRNA sequence assigned these six isolates to five different species, namely <i>Mycobacterium chelonae</i> (BN1983), <i>M. cosmeticum</i> (BN1984 and N041), <i>M. farcinogenes</i> (SNSK5), <i>M. mucogenicum</i> (BN1956), and <i>M. senegalense</i> (BN1985). However, the identification relied solely on the highest percent identity of the 16S rRNA gene, raising concerns about the taxonomic ambiguity of these species. Comprehensive whole genome sequencing (WGS) and extended genomic comparisons using multilocus sequence typing (MLST), average nucleotide identity (ANI), and digital DNA–DNA hybridization (dDDH) led to the reclassification of BN1985 and SNSK5 as <i>M. conceptionense</i> while confirming BN1983 as <i>M. chelonae</i> and BN1984 and N041 as <i>M. cosmeticum</i>. Notably, the analysis of the BN1956 isolate revealed a potential new species that is proposed here as <i>M. mucogenicum</i> subsp. <i>phocaicum</i> sp. nov. Common genes encoding “mycobacterial” virulence proteins, such as PE and PPE family proteins, MCE, and YrbE proteins, were detected in all six isolates. Two species, namely <i>M. chelonae</i> and <i>M. cosmeticum</i>, appear to have horizontally acquired T6SS-II (<i>clpB</i>), catalase (<i>katA</i>), GroEL (<i>groel</i>), and capsule (<i>rmlb</i>) from distantly related environmental bacteria such as <i>Klebsiella</i> sp., <i>Neisseria</i> sp., <i>Clostridium</i> sp., and <i>Streptococcus</i> sp. This study provides the first draft genome sequence of RGM isolates currently circulating in <i>B. splendens</i> and underscores the necessity of WGS for the identification and classification of mycobacterial species.

Mohammad Rabiei, Milton M. McAllister, Natalie R. Gassman et al.

This study delves into the pathogenesis of virulent genotype VII strains of the Newcastle disease virus (NDV), focusing on experimentally infected birds. Predominant and consistent lesions observed include bursal atrophy and extensive depletion of all lymphoid tissues. Immunohistochemistry (IHC) analysis, targeting apoptosis (Caspase-3), necroptosis (MLKL), and NDV markers, indicates that bursal atrophy is linked to a non-apoptotic programmed cell death pathway known as “necroptosis”. Repair assisted damage detection (RADD) of the bursa reveal oxidative DNA damage patterns consistent with programmed cell death, aligning with MLKL expression. Contrastingly, in the spleen, our findings suggest that necrosis (non-programmed cell death) predominantly contributes to lymphoid depletion. This conclusion is supported by evidence of karyorrhexis, fibrinous inflammation, RADD analyses, and IHC. Moreover, in addition to being pathogenic in its own right, NDV caused extensive and rapid lymphoid depletion that should be expected to contribute to profound immunosuppression. The elucidation of necroptosis in NDV-infected chickens provides a good rationale to investigate this mechanism in other paramyxoviral diseases such as human measles.

Tian Han, Wei Cao, Lize San et al.

Japanese flounder is usually gonochoristic, with gonads that are either testes or ovaries. Here, we report an unusual case of hermaphroditism in Japanese flounder captured from the Bohai Sea. In the intersex flounder, the membrane of the upper ovary was closely connected to the abdominal muscles and internal organs, and the eggs filled the entire abdomen. The lower ovary was small and closely connected to the testes. The testes contained few fully mature sperm. Both eggs and sperm were capable of fertilization. The levels of several reproduction-related hormones (17β-estradiol, 11-ketotestosterone, 17α, 20β-dihydroxyprogesterone, luteinizing hormone, follicle-stimulating hormone, and testosterone) in the intersex flounder were intermediate, between those in females and males. The results showed that the heterozygosity of the intersex flounder was 0.632, and there were 28 single-nucleotide polymorphisms in the <i>cyp21a</i> gene. Compared with that of wild flounder, the activity of 21-hydroxylase was reduced by approximately 20.0%, and expressions of <i>cyp19a</i>, <i>amh</i>, and <i>dmrt1</i> differed. We present the first report of its kind, detailing the anatomy, hormonal endocrinology, molecular biology, and physiology of the intersex Japanese flounder.

K. Garcia, Mina Weakley, T. Do et al.

Ticks and tick-borne diseases such as babesiosis, anaplasmosis, ehrlichiosis, Lyme disease, Crimean Congo hemorrhagic fever, and Rocky Mountain spotted fever pose a significant threat to animal and human health. Tick-borne diseases cause billions of dollars of losses to livestock farmers annually. These losses are partially attributed to the lack of sensitive, robust, cost effective and efficient diagnostic approaches that could detect the infectious pathogen at the early stages of illness. The modern nucleic acid-based multiplex diagnostic approaches have been developed in human medicine but are still absent in veterinary medicine. These powerful assays can screen 384 patient samples at one time, simultaneously detect numerous infectious pathogens in each test sample and provide the diagnostic answer in a few hours. Development, commercialization, and wide use of such high throughput multiplex molecular assays in the cattle tick-borne disease surveillance will help in early detection and control of infectious pathogens in the animal reservoir before community spread and spillover to humans. Such approaches in veterinary medicine will save animal life, prevent billions of dollars of economic loss to cattle herders and reduce unwanted stress to both human and animal health care systems. This literature review provides recent updates on molecular diagnostics of tick-borne pathogens and discusses the importance of modern nucleic acid high throughput multiplex diagnostic approaches in the prevention of tick-borne infection to livestock.

Antje Glass, Andrea Springer, Marie-Kristin Raulf et al.

Lyme borreliosis, caused by Borrelia burgdorferi sensu lato (s.l.) spirochaetes, is the most common tick-borne disease (TBD) in the Northern Hemisphere. Rising incidences indicate that its epidemiology may be affected by global changes. Therefore, the current study aimed to assess changes in tick infection rates with Borrelia spp. over a 15-year monitoring period in the city of Hanover, Germany, as a follow-up to previous prevalence studies (years 2005, 2010 and 2015). To assess the epidemiological risk, ticks of the Ixodes ricinus/inopinatus-complex were sampled from April to October 2020 by the flagging method at 10 frequently visited recreation areas in Hanover. Analysis by quantitative real-time PCR of 2100 individual ticks revealed an overall Borrelia prevalence of 25.5% (535/2100). Regarding different tick developmental stages, nymphs showed a significantly lower Borrelia prevalence (18.4% [193/1050]) than adult ticks (32.6% [342/1050]). Comparison with previous years revealed a stable total Borrelia prevalence along with consistent infection rates in the different developmental stages over the 15-year monitoring period. Borrelia species differentiation by Reverse Line Blot was successful in 67.3% of positive ticks collected in 2020, with B. afzelii being the dominating species (59.2% of the differentiated infections), besides B. burgdorferi sensu stricto (s.s.), B. garinii, B. valaisiana, B. spielmanii, B. bavariensis and B. bissettiae and the relapsing fever spirochaete B. miyamotoi. Additionally, the proportion of infections attributed to B. afzelii showed a significant increase in 2020 compared to 2005 and 2015 (59.2% vs. 37.6% and 32.0% of successfully differentiated infections, respectively). Coinfections with Anaplasma phagocytophilum and Rickettsia spp. stayed stable comparing 2020 with previous years. Therefore, although changes in the Borrelia prevalence in questing ticks were not observed throughout the 15-year monitoring period, shifts in Borrelia species distribution may alter the epidemiological risk.

Joe S. Smith, Adrien-Maxence Hespel, Jessica D. Garcia et al.

A one-year-old alpine wether was presented for emergency evaluation of stranguria. Diagnostics identified a moderately distended bladder and mild dehydration. Preliminary lateral radiographs identified two metallic structures consistent with projectile pellets in the pelvic and perineal regions and no evidence of radiopaque uroliths. A tube cystostomy was performed, and a contrast urethrogram revealed one of the pellets in the perineal region was in proximity to the urethral obstruction. Subsequent radiography and ultrasound identified the pellet as being within the lumen of the urethra. Examination of the trichotomized skin revealed two scars, including a scar over the paralumbar fossa in the region of the urinary bladder suggestive of a projectile injury. The pellet was removed by a perineal urethrotomy. The patient was able to spontaneously urinate after urethrotomy, passed a tube cystostomy challenge two weeks after surgery, and was discharged. No complications were reported. While uncommon in the veterinary and comparative medical literature, clinicians should consider the potential for projectile pellets to migrate into the urinary tract after initial injury.

Takashi Sasaki, Sae Tsubakishita, Yoshikazu Tanaka et al.

C. Webster, S. Center, J. Cullen et al.

Abstract This consensus statement on chronic hepatitis (CH) in dogs is based on the expert opinion of 7 specialists with extensive experience in diagnosing, treating, and conducting clinical research in hepatology in dogs. It was generated from expert opinion and information gathered from searching of PubMed for manuscripts on CH, the Veterinary Information Network for abstracts and conference proceeding from annual meetings of the American College of Veterinary Medicine and the European College of Veterinary Medicine, and selected manuscripts from the human literature on CH. The panel recognizes that the diagnosis and treatment of CH in the dog is a complex process that requires integration of clinical presentation with clinical pathology, diagnostic imaging, and hepatic biopsy. Essential to this process is an index of suspicion for CH, knowledge of how to best collect tissue samples, access to a pathologist with experience in assessing hepatic histopathology, knowledge of reasonable medical interventions, and a strategy for monitoring treatment response and complications.

Karyn E. O’Connell, Amy M Mikkola, Aaron M Stepanek et al.

Matteo Cerquetella, Andrea Marchegiani, Giacomo Rossi et al.

The present case report describes the effects of orally administered fecal microbiota transplantation (FMT) (frozen capsules) in a dog suffering from relapsing chronic diarrhea, needing a continuous low prednisolone dose to maintain the condition under acceptable control. Through FMT, we aimed at evaluating the possibility of improving the clinical score and/or reducing/suspending steroid administration. During a first period of strict monitoring (21 days), the canine inflammatory bowel disease activity index (CIBDAI) score passed from mild to clinically insignificant disease. Furthermore, two additional gastrointestinal signs that had been reported, bloating and episodes of painful defecation, rapidly improved (bloating) or even resolved (painful defecation). The patient was then followed for 18 months (to the authors' knowledge, the longest follow-up time ever reported in a dog), during which no serious relapses occurred and no increase in prednisolone dose was necessary. No adverse clinical effects were ever reported during monitoring. The present description provides a further experience increasing those already present in the veterinary literature, in which an agreement on how to use FMT has not yet been achieved although strongly needed and recommended.

Lijuan Gao, Qi Yan, Jie Li et al.

To investigate the effects of the dietary inclusion of elephant grass on the growth performance, blood profiles, carcass characteristics, ileum and stomach microbiota of fattening pigs, pigs were fed one of seven diets including a basal diet (Control), and six treatments, where the basal diet was supplemented with 10%, 15% or 20% of elephant grass, Cenchrus purpureus cv. Guiminyin (CpGui10, CpGui15, CpGui20) or cv. Purple (CpP10, CpP15, CpP20). Results showed that supplementation of 20% CpGui in the diet significantly increased (P &lt; 0.05) average daily gain (ADG) and gain to feed (G/F) ratio by the end of the experiment. Additionally, pigs fed the CpGui20 diet showed higher (0.01 &lt; P &lt; 0.05) slaughter weight and tended to have increased loin-eye area and lean meat percentage, and, decreased backfat thickness compared with control pigs. Furthermore, 16S ribosomal DNA gene amplicon profiling showed that the inclusion of elephant grass in the diet was associated with modulation of the ileum and stomach microbiota composition at the order level. Relative abundance of the Lactobacillales order in the ileum and stomach increased with different proportions of elephant grass, while that of Enterobacteriales decreased. In conclusion, these results indicate that at up to 20% inclusion in the diet of pigs, elephant grass can promote enhanced growth performance and carcass characteristics, and, modulate the ileum and stomach microbiota composition of the pigs.

Md Bashir Uddin, Mohammad Nurul Alam, Mahmudul Hasan et al.

Zoonotic and antimicrobial-resistant <i>Escherichia coli</i> (hereafter, <i>E. coli</i>) is a global public health threat which can lead to detrimental effects on human health. Here, we aim to investigate the antimicrobial resistance and the presence of <i>mcr-1</i> gene in <i>E. coli</i> isolated from chicken feces. Ninety-four <i>E. coli</i> isolates were obtained from samples collected from different locations in Bangladesh, and the isolates were identified using conventional microbiological tests. Phenotypic disk diffusion tests using 20 antimicrobial agents were performed according to CLSI-EUCAST guidelines, and minimum inhibitory concentrations (MICs) were determined for a subset of samples. <i>E. coli</i> isolates showed high resistance to colistin (88.30%), ciprofloxacin (77.66%), trimethoprim/sulfamethoxazole (76.60%), tigecycline (75.53%), and enrofloxacin (71.28%). Additionally, the pathotype <i>eaeA</i> gene was confirmed in ten randomly selected <i>E. coli</i> isolates using primer-specific polymerase chain reaction (PCR). The presence of <i>mcr-1</i> gene was confirmed using PCR and sequencing analysis in six out of ten <i>E. coli</i> isolates. Furthermore, sequencing and phylogenetic analyses revealed a similarity between the catalytic domain of <i>Neisseria meningitidis</i> lipooligosaccharide phosphoethanolamine transferase A (LptA) and MCR proteins, indicating that the six tested isolates were colistin resistant. Finally, the findings of the present study showed that <i>E. coli</i> isolated from chicken harbored <i>mcr-1</i> gene, and multidrug and colistin resistance. These findings accentuate the need to implement strict measures to limit the imprudent use of antibiotics, particularly colistin, in agriculture and poultry farms.

O. S. Osipova, M. A. Volkova, S. V. Frolov et al.

Data on tests of chickens for their immune responses to infection with low pathogenic А/Н9N2 avian influenza virus isolates belonging to Y-280 and G1 genetic lines are presented in the paper. CD4⁺/CD8⁺ ratios were determined with flow cytometry for initial immune status examination and for detection of apparent immune system disorders. Quantitative analysis of peripheral blood lymphocyte subpopulations in chickens revealed changes characteristic of the immune suppression. Analysis of dynamics of T- and B-lymphocyte levels in blood of the infected chickens revealed decrease in relative T-lymphocyte counts and increase in relative B-lymphocyte counts. T-lymphocyte subpopulation composition expressed as CD4⁺/CD8⁺ ratio (%) changed after the infection: CD4⁺ cell proportion was found to decrease whereas CD8⁺ cell proportion increased. According to literature data, immune response activated by vaccination induces the reverse dynamics towards to increase in CD4⁺/CD8⁺ ratio. Both cell-mediated immunity and humoral immunity play role in development of the immune response in chickens infected with avian influenza viruses. Apparent humoral immune response was detected by serological tests of sera taken from chickens on day 14 after infection. Mean specific anti-A/H9N2 AIV antibody titre in all groups of test chickens infected with low pathogenic avian influenza virus isolates was higher than 6 log₂ . High level of specific antibodies to avian influenza virus was indicative of postvaccinal humoral immune response development.

M. Francis

This brief review discusses some recent advances in vaccine technologies with particular reference to their application within veterinary medicine. It highlights some of the key inactivated/killed approaches to vaccination, including natural split-product and subunit vaccines, recombinant subunit and protein vaccines, and peptide vaccines. It also covers live/attenuated vaccine strategies, including modified live marker/differentiating infected from vaccinated animals vaccines, live vector vaccines, and nucleic acid vaccines.

Emily K. Hill, Julang Li

Nanoparticles have been used as diagnostic and therapeutic agents in the human medical field for quite some time, though their application in veterinary medicine and animal production is still relatively new. Recently, production demands on the livestock industry have been centered around the use of antibiotics as growth promoters due to growing concern over microbial antibiotic resistance. With many countries reporting increased incidences of antibiotic-resistant bacteria, laws and regulations are being updated to end in-feed antibiotic use in the animal production industry. This sets the need for suitable alternatives to be established for inclusion in feed. Many reports have shown evidence that nanoparticles may be good candidates for animal growth promotion and antimicrobials. The current status and advancements of nanotechnological applications in animal production will be the focus of this review and the emerging roles of nanoparticles for nutrient delivery, biocidal agents, and tools in veterinary medicine and reproduction will be discussed. Additionally, influences on meat, egg, and milk quality will be reviewed.

Jing Wang, Zhenbao Ma, Z. Zeng et al.

Antimicrobial resistance is an urgent global health challenge in human and veterinary medicine. Wild animals are not directly exposed to clinically relevant antibiotics; however, antibacterial resistance in wild animals has been increasingly reported worldwide in parallel to the situation in human and veterinary medicine. This underlies the complexity of bacterial resistance in wild animals and the possible interspecies transmission between humans, domestic animals, the environment, and wildlife. This review summarizes the current data on expanded-spectrum β-lactamase (ESBL), AmpC β-lactamase, carbapenemase, and colistin resistance genes in Enterobacteriaceae isolates of wildlife origin. The aim of this review is to better understand the important role of wild animals as reservoirs and vectors in the global dissemination of crucial clinical antibacterial resistance. In this regard, continued surveillance is urgently needed worldwide.