Veterinary Research Communications最新文献

{"title":"Impact of melatonin injection in improving ovarian function in aged female pigeon.","authors":"Ying Wang, Haodong Zhang, Jing Chen, Dongzhi Miao, Xinyan Mao, Wanqing Li, Haiming Yang, Zhiyue Wang","doi":"10.1007/s11259-026-11260-x","DOIUrl":"https://doi.org/10.1007/s11259-026-11260-x","url":null,"abstract":"<p><p>Melatonin (MT) has been shown to extend laying period in aged hens, but its effects on aging pigeons remain unclear. 36 pairs of 5-year-old White King pigeons were assigned to either a treatment group receiving 1 mg of MT for five days or a control group given saline. The effect of MT injection on egg production in pigeon, assess histological characteristics of follicles, antioxidant parameters level and the related gene mRNA levels, steroid hormone levels and the expressions of synthesis genes on the fifth day of the laying interval. MT treatment significantly improved various aspects of egg quality. Moreover, MT increased follicle diameter and granulosa cell layer (GCL) thickness (P < 0.05). MT levels were elevated in plasma and hierarchy follicles yolks (P < 0.05). Progesterone concentrations rose in plasma (P < 0.05), however, estradiol levels decreased in plasma, F1 and F2 yolks (P < 0.05). MT also reduced ROS and MDA levels in plasma and F1 yolk (P < 0.05). Meanwhile, activities of SOD, TAC, and GSH-PX were significantly increased (P < 0.05). MT upregulated SOD1, CAT, and BCL2 mRNA levels in ovary and F1 GCL (P < 0.05). MT significantly increased ovarian expressions of HSD3B1 and CYP11A1, reducing HSD17B1 mRNA levels (P < 0.05); In F1 and F2 GCL, CYP11A1, CYP17A1, and CYP19A1 expressions were all elevated (P < 0.05). These findings suggest that MT promotes hierarchy follicle maturation, reduces apoptosis, thus extending egg-laying period in aging pigeons.</p>","PeriodicalId":23690,"journal":{"name":"Veterinary Research Communications","volume":"50 4","pages":""},"PeriodicalIF":2.0,"publicationDate":"2026-05-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147843545","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Morphological description of the tongue of the Boa constrictor.","authors":"Thamara Cozzi Gonçalves, Isabella Bittencourt Pires Chaves, Rogério Antonio Ribeiro Rodrigues, Elane Guerreiro Giese, Érika Branco, Ana Rita de Lima","doi":"10.1007/s11259-026-11248-7","DOIUrl":"10.1007/s11259-026-11248-7","url":null,"abstract":"<p><p>The Amazon biome hosts a rich diversity of reptile species, including Boa constrictor (Linnaeus, 1758), widely distributed throughout Brazil and belonging to the order Squamata. Despite its ecological importance, detailed descriptions of lingual morphology in this species remain limited. This study aimed to describe the tongue of B. constrictor using macroscopic, histological, and scanning electron microscopy (SEM) analyses. Four specimens obtained post mortem after road accidents were analyzed. It is important to consider that freezing and thawing procedures may have influenced tissue preservation. Macroscopically, the tongue is elongated, bifurcated, and smooth, with no visible papillae or median groove. However, SEM revealed a median groove in the body of the tongue. Histologically, the tongue is lined by stratified squamous epithelium with slight keratinization, supported by connective tissue and skeletal muscle bundles. No papillae, taste buds, or salivary glands were observed under the conditions of this study. These findings support the sensory role of the tongue in snakes and contribute to comparative anatomical knowledge.</p>","PeriodicalId":23690,"journal":{"name":"Veterinary Research Communications","volume":"50 4","pages":""},"PeriodicalIF":2.0,"publicationDate":"2026-05-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13152927/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147843645","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Oculodermal melanocytosis (Nevus of Ota) in a Great Dane with concurrent ocular abnormalities: a case report.","authors":"Natalia Ziółkowska, Anna Cisło-Sankowska, Marta Pietruszyńska","doi":"10.1007/s11259-026-11243-y","DOIUrl":"10.1007/s11259-026-11243-y","url":null,"abstract":"<p><strong>Background: </strong>Oculodermal melanocytosis (ODM) is an uncommon congenital melanocytic disorder infrequently reported in dogs. It is characterized by dermal and ocular hyperpigmentation involving neural crest-derived tissues and may predispose affected dogs to secondary ocular complications such as glaucoma or, in exceptional cases, malignant transformation.</p><p><strong>Case presentation: </strong>A 4-year-old neutered male Great Dane was presented with unilateral facial and ocular hyperpigmentation. Ophthalmic examination revealed marked pigmentation and thickening of the right iris, perilimbal and peripheral corneal pigmentation, and diffuse uveal involvement. Bilateral uveal cysts were identified. Intraocular pressure was within reference intervals but asymmetric between eyes. Fundus examination demonstrated focal tapetal hyperreflectivity and vascular attenuation in the right eye, and electroretinography confirmed reduced retinal function. Six months later, secondary glaucoma developed, necessitating enucleation. Histopathology revealed diffuse infiltration of heavily pigmented cells without cytologic atypia or mitotic activity within the sclera, uveal tract, perioptic connective tissue, and cornea. Marked goniodysgenesis was also identified, providing a structural basis for impaired aqueous outflow.</p><p><strong>Conclusion: </strong>This case expands the clinicopathologic characterization of canine oculodermal melanocytosis by documenting concurrent breed-associated uveal cysts and histologically confirmed goniodysgenesis in addition to retinal dysfunction and secondary glaucoma. The findings highlight the multifactorial nature of ocular disease in affected dog and emphasize that pigmentary disorders may coexist with independent structural abnormalities influencing intraocular pressure and retinal function. Comprehensive and repeated evaluation of both anterior and posterior segment structures is therefore essential when managing complex unilateral ocular pigmentation.</p>","PeriodicalId":23690,"journal":{"name":"Veterinary Research Communications","volume":"50 4","pages":""},"PeriodicalIF":2.0,"publicationDate":"2026-05-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13139254/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147821376","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Phytogenic and natural immunostimulants in the prevention of Lactococcus garvieae infection: an eco-friendly approach.","authors":"Ehsan Ahmadifar, Sevdan Yilmaz, Mohammed A E Naiel, Deepak Chandran, Morteza Yousefi, Najmeh Sheikhzadeh, Sureshkumar Rajalingam, Narges Dargahi","doi":"10.1007/s11259-026-11229-w","DOIUrl":"10.1007/s11259-026-11229-w","url":null,"abstract":"<p><p>Aquaculture is developing in many countries to meet the rising protein demand associated with a rapidly growing human population. However, intensification of production brings with it challenges such as deteriorating water quality and increasing disease outbreaks. These conditions lead to an increased risk of infectious diseases and led to higher mortality rates, which causes economic losses. Lactococcosis, particularly that caused by the Gram-positive bacterium Lactococcus garvieae, is one of the most common of these problems and can cause significant losses in various fish species. The intensive use of antibiotics for control purposes creates additional risks in terms of antimicrobial resistance, environmental pollution, and food safety. Therefore, natural feed additives have gained importance in recent years. Certain additives that support immune responses and increase disease resistance in fish have become prominent. Among these, phytobiotics, probiotics, prebiotics, and synbiotics are the most well-known and effective. Their widespread availability, lower cost, and environmental safety make these additives considered an alternative approach to aquaculture. Studies show that these additives strengthen both innate and adaptive immune responses, reduce infection severity, and reduce mortality associated with L. garvieae infections. However, there are still gaps in knowledge regarding how these substances regulate mechanisms such as the immune system, inflammatory processes, antioxidant defenses, and interactions with pathogens. This review aims to clarify these mechanisms by bringing together scientific data obtained in recent years. It also discusses how the information obtained can contribute to the development of safer feed additive strategies and the development of new vaccine approaches. This aims to support the establishment of a more sustainable production structure in the aquaculture sector.</p>","PeriodicalId":23690,"journal":{"name":"Veterinary Research Communications","volume":"50 4","pages":""},"PeriodicalIF":2.0,"publicationDate":"2026-05-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147821336","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Probiotic potential of lactic acid bacteria isolated from canine and feline microbiota: functional profiling and host-adapted benefits.","authors":"Fadime Kiran, Hazal Kibar Demirhan, Sedat Sevin","doi":"10.1007/s11259-026-11242-z","DOIUrl":"10.1007/s11259-026-11242-z","url":null,"abstract":"<p><p>The global rise in pet ownership has increased demand for health-promoting products, particularly probiotics designed to support gastrointestinal and immune health in companion animals. However, most commercial products rely on non-host-adapted strains, which may limit gastrointestinal colonization and host-specific benefits. To address this gap, 56 bacterial isolates were obtained from the fecal and milk microbiota of clinically healthy dogs and cats. Among these, Limosilactobacillus reuteri DF/KS2, derived from the fecal microbiota of a Kangal Shepherd dog, and Enterococcus faecium CM/BS2 derived from the milk microbiota British Shorthair cat, were selected based on their broad-spectrum antimicrobial activity. Both strains exhibited a safe profile, as evidenced by γ-hemolysis and susceptibility to a panel of clinically relevant antibiotics. Under simulated gastrointestinal conditions, CM/BS2 and DF/KS2 tolerated highly acidic environments and demonstrated resilience against digestive enzymes and bile salts. Furthermore, both isolates displayed strong auto-aggregation and co-aggregation abilities with key pathogens, while adhesion assays using Caco-2 cells confirmed their capacity to inhibit pathogen attachment. Immunomodulatory evaluations further revealed that both strains effectively reduced pro-inflammatory cytokines (TNF-α, IL-1β, IL-6) and enhanced anti-inflammatory IL-10 production in canine and feline macrophages. Optimal growth occurred at 37 °C after 24 h in 2% molasses medium, and shelf-life studies demonstrated that freeze-dried cultures retained high viability over six months at - 20 °C. Collectively, these findings highlight the probiotic potential of host-adapted L. reuteri DF/KS2 and E. faecium CM/BS2, emphasizing their suitability for inclusion in species-specific probiotic formulations aimed at supporting gastrointestinal and immune health in dogs and cats.</p>","PeriodicalId":23690,"journal":{"name":"Veterinary Research Communications","volume":"50 4","pages":""},"PeriodicalIF":2.0,"publicationDate":"2026-05-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13139239/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147821402","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Molecular insights into domestic cat hepatitis B virus linking genome to function.","authors":"Sofija Šolaja, Vesna Milićević, Dimitrije Glišić, Andrea Radalj, Miloš Đurić, Aleksandra Knežević, Jakov Nišavić","doi":"10.1007/s11259-026-11236-x","DOIUrl":"10.1007/s11259-026-11236-x","url":null,"abstract":"<p><p>Domestic cat hepatitis B virus (DCHBV) is a member of the Hepadnaviridae family and has been associated with hepatocellular carcinoma (HCC) in cats. This study aimed to determine the prevalence of DCHBV and associations with feline immunodeficiency virus (FIV), feline leukaemia virus (FeLV) and feline coronavirus (FCoV) infections in cats in Serbia, and to characterise the detected DCHBV genomes. Whole blood, serum and liver samples from 308 animals were screened by real-time (RT-)PCR for DCHBV, FIV, FeLV, and FCoV. The prevalence of DCHBV was 2.60%, with no significant associations observed between DCHBV infection and age, sex, or coinfection status. Three whole genome sequences were obtained, and phylogenetic analysis demonstrated that the Serbian strains belong to genotype A. Molecular analysis revealed three unique nonsynonymous substitutions in the S ORF. Within the C ORF, a 28-amino acid N-terminal precore region with conserved cysteine residues critical for protein maturation was identified, along with the C-terminal arginine-rich domain. A putative core promoter region was detected, containing two motifs analogous to the pgRNA and pcRNA initiator elements described in hepatitis B virus (HBV). DCHBV sequences contained two 11-bp direct repeats with DR2 located in X ORF and DR1 positioned in the C ORF. This study represents the first report of DCHBV in Serbia, providing new insights into its epidemiology and genomic features. The findings expand current knowledge of its molecular diversity and underscore the importance of genomic characterisation for understanding its role in liver disease development.</p>","PeriodicalId":23690,"journal":{"name":"Veterinary Research Communications","volume":"50 4","pages":""},"PeriodicalIF":2.0,"publicationDate":"2026-05-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13135525/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147821412","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Widespread gyrovirus co-infections in backyard chickens in Türkiye: molecular and Phylogenetic insights.","authors":"Mustafa Ozan Atasoy, Turhan Turan, Selda Duran Yelken, Remziye Özbek, Hakan Işıdan","doi":"10.1007/s11259-026-11241-0","DOIUrl":"10.1007/s11259-026-11241-0","url":null,"abstract":"<p><strong>Introduction: </strong>Gyroviruses are widespread small DNA viruses infecting poultry and other hosts, yet their diversity and coinfection dynamics in backyard systems remained poorly understood.</p><p><strong>Materials and methods: </strong>Tissue samples from 100 clinically healthy backyard chickens across five provinces in Türkiye, between 2020 and 2021, were screened using species-specific PCR assays targeting six gyroviruses.</p><p><strong>Results: </strong>The Gyroviral DNA was detected in 90.0% of samples (90/100), with CAV identified in 71.0% (71/100), AGyV2 in 59.0% (59/100), GyV3 in 8.0% (8/100), GyV4 in 22.0% (22/100), GyVTu789 in 19.0% (19/100), and GyV7-SF in 18.0% (18/100) of samples. Co-infections were frequent, most notably between CAV and AGyV2, with a co occurrence rate of 25.6%. Phylogenetic analysis of partial VP1 sequences revealed that circulating strains were largely consistent with global lineages, while also displaying detectable genetic variability, particularly within GyV4. Notably, GyVTu789 and GyV7-SF were identified for the first time in chickens in Türkiye, extending their known geographic range. The high rate of co-detection highlights the concurrent circulation of multiple gyroviruses in backyard poultry populations.</p><p><strong>Conclusions: </strong>These findings provide a comprehensive overview of gyrovirus diversity and circulation dynamics, pinpointing the need for continued surveillance to better understand their epidemiology and potential impact on poultry health.</p>","PeriodicalId":23690,"journal":{"name":"Veterinary Research Communications","volume":"50 4","pages":""},"PeriodicalIF":2.0,"publicationDate":"2026-05-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13135576/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147821426","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Prevalence and antibiotic resistance profile of Staphylococcus pseudintermedius in pyodermic dogs in Asia: a systematic review and meta-analysis.","authors":"Mohammad Farzad Afshar, Nasir Ahmad Sarwary, Syafiqah Ishak, Tahera Hashimi, Priscilla Nasthalina Jabing, Mohammed Babatunde Sadiq, Chen Hui Cheng","doi":"10.1007/s11259-026-11231-2","DOIUrl":"https://doi.org/10.1007/s11259-026-11231-2","url":null,"abstract":"<p><p>Staphylococcus pseudintermedius is the primary bacterial agent associated with canine pyoderma, with rising concern over methicillin-resistant strains in Asia. This systematic review and meta-analysis aimed to determine the prevalence of methicillin-susceptible (MSSP) and methicillin-resistant (MRSP) S. pseudintermedius from canine skin infections and to evaluate their antimicrobial resistance profiles. Following PRISMA (Preferred Reporting Items for Systematic Review and Meta-Analysis) guidelines, studies published between 2015 and 2024 were retrieved from Scopus, PubMed, Web of Science, and Google. Only cross-sectional studies from Asian countries reporting disk diffusion susceptibility testing in dogs with pyoderma were included. Fifteen studies met the inclusion criteria, with overall moderate methodological quality. Fourteen studies were included in prevalence analyses. The pooled prevalence of MSSP was 27.9% (95% CI: 18.8-39.3) and MRSP was 30.7% (95% CI: 21.3-42.1), with high heterogeneity between the included studies (I² = 93.85%; p < 0.001). The pooled prevalence of the mecA gene among MRSP was 11.9%. Meta-regression revealed no significant difference between MSSP and MRSP prevalence (p = 0.853). MSSP isolates had the lowest resistance to amoxicillin-clavulanic acid and oxacillin, whereas MRSP exhibited broader resistance, particularly to oxacillin, clindamycin, and doxycycline. These findings highlight the substantial burden of MRSP in canine pyoderma in Asia and reinforce the need for susceptibility-guided therapy and strengthened antimicrobial stewardship.</p>","PeriodicalId":23690,"journal":{"name":"Veterinary Research Communications","volume":"50 4","pages":""},"PeriodicalIF":2.0,"publicationDate":"2026-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13135009/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147821374","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Co-infection with a viral pathogen (Theiler's murine encephalomyelitis virus) tended to improve host tolerance but significantly enhanced resistance to Heligmosomoides bakeri.","authors":"Insani H Zulfa, Rennos Fragkoudis, Andrea Doeschl-Wilson, Jos G M Houdijk, Margo Chase-Topping, Richard I Bailey, Spiridoula Athanasiadou","doi":"10.1007/s11259-026-11217-0","DOIUrl":"https://doi.org/10.1007/s11259-026-11217-0","url":null,"abstract":"<p><p>The host's ability to clear parasites (resistance) and their capacity to reduce the impact of a given parasite burden (tolerance) is often described under conditions of a single pathogen challenge. We developed a mouse infection model to investigate the impact of co-infection on host resistance and tolerance to Heligmosomoides bakeri. C57BL/6 mice were infected with the helminth parasite H. bakeri and Theiler's murine encephalomyelitis virus (TMEV), that both reside in the small intestine. Two infection protocols were used to also investigate the impact of the order of pathogen administration on host resistance and tolerance (H-V protocol: helminth first and V-H protocol: virus first). Non-infected controls, H.bakeri only and TMEV only infected animals were also included. Our data showed that co-infection in the H-V protocol, resulted in significantly improved resistance to H.bakeri, as measured by 30% lower number of H. bakeri recovered (p = 0.023) and a 57% reduction in eggs in colon (p = 0.035) compared to mice infected with H. bakeri only. It also led to a 39% improvement in tolerance against H. bakeri infection compared to mice infected with H. bakeri only (p = 0.052). The positive impact on the resistance to H. bakeri was evident but less pronounced in mice in the V-H protocol. Our hypothesis that resistance and tolerance of animals are penalised from increased pathogen load is rejected with important implications for disease control.</p>","PeriodicalId":23690,"journal":{"name":"Veterinary Research Communications","volume":"50 4","pages":""},"PeriodicalIF":2.0,"publicationDate":"2026-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13134990/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147821322","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Genotypic and phenotypic evidence of extended-spectrum β-lactamase and carbapenemase-producing shigatoxigenic and intimin-producing Escherichia coli in diarrheic calves in Bangladesh: A hidden zoonotic and public health risk.","authors":"Plabon Ketan Barua, Uaye Mya, Mukta Das Gupta, Partha Paul, Snigdha Das, Ashutosh Das","doi":"10.1007/s11259-026-11203-6","DOIUrl":"https://doi.org/10.1007/s11259-026-11203-6","url":null,"abstract":"<p><p>Shiga toxin-producing Escherichia coli (STEC) is a pathotype of E. coli associated with a wide variety of diarrhoea in neonatal calves, causing a global economic loss in the dairy industry with significant zoonotic risks via STEC and intimin-producing STEC, resulting in enteric and systemic illness, including diarrhoea, haemorrhagic colitis (HC), and haemolytic uremic syndrome (HUS) in humans. The presence of multidrug-resistant (MDR) STEC in neonatal diarrhoeic calves represents a significant public health concern and limits available therapeutic options. This study investigated the presence of extended-spectrum β-lactamase (ESBL) and carbapenemase-producing STEC isolates and their genotypic combinations of virulence and resistance genes in diarrhoeal calves. A total of 75 rectal swabs from diarrhoeic calves aged ≤ 12 weeks were sampled from three districts of Bangladesh, screened using selective culture and polymerase chain reaction (PCR), followed by phenotypic antimicrobial susceptibility profiling and phenotypic and genotypic screening for ESBL- and carbapenemase-production. The E. coli isolation rate among diarrhoeic calves was 80% (60/75; 95% CI: 69.17-88.35). PCR screening revealed the presence of stx1, stx2, and eae virulence genes, and the prevalence of E. coli isolates harbouring these virulence genes was 13.33% (10/75; 95% CI: 6.5-23.1). The ten virulent isolates included five stx-positive, four stx/eae-positive and one eae-positive E. coli. All the virulent isolates (100%) were resistant to ciprofloxacin and meropenem; however, eight (80%) of the tested isolates were susceptible to gentamycin, and 60% were susceptible to amoxicillin-clavulanate. All virulent E. coli isolates were MDR. We observed that 5 (50%) of the virulent E. coli isolates were ESBL producers, and 7 (70%) were carbapenemase producers. The results for phenotypes and genotypes of ESBL- and carbapenemase-producing strains were not concordant. At least one ESBL gene was present in nine of the ten virulent isolates examined, including four ESBL phenotype-negative isolates. Carbapenemase-producing genotypes were significantly more common in isolates with multiple virulence genes than in those with a single virulence gene (p = 0.001). To the best of our knowledge, this is the first report on ESBL- and carbapenemase-producing MDR STEC in diarrhoeic calves in Bangladesh.</p>","PeriodicalId":23690,"journal":{"name":"Veterinary Research Communications","volume":"50 4","pages":""},"PeriodicalIF":2.0,"publicationDate":"2026-04-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147782805","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}