Search Results (867)

Mycoplasma bovis (M. bovis) is capable of causing pneumonia, arthritis, mastitis, and various other ailments in cattle of all age groups, posing a significant threat to the healthy progression of the worldwide cattle industry. The invasion of non-phagocytic host cells serves as a pivotal mechanism enabling M. bovis to evade the immune system and penetrate mucosal barriers, thereby promoting its spread. To investigate the differences in M. bovis invasion into four types of non-phagocytic cells (Madin–Darby bovine kidney (MDBK) cells, embryonic bovine lung (EBL) cells, bovine embryo tracheal (EBTr) cells and bovine turbinate (BT) cells) and further elucidate its invasion mechanism, this study first optimized the experimental methods for M. bovis invasion into cells. Utilizing laser scanning confocal microscopy, transmission electron microscopy, and high-content live-cell imaging systems, the invasion process of M. bovis into four types of non-phagocytic cells was observed. The invasion rates of three different strains of M. bovis (PG45, 07801, 08M) were quantified through the plate counting method. In order to clarify the specific pathway of M. bovis invasion into cells, chlorpromazine (CPZ), amiloride (AMI), and methyl-β-cyclodextrin (M-β-CD) were used to inhibit CLR-mediated clathrin-dependent endocytosis (CDE) pathway, macropinocytosis, and lipid raft pathway, respectively. Subsequently, the invasion rates of PG45 into these four types of cells were measured. Using siRNA technology, the expression of clathrin (CLR) in EBL cells was knocked down to further verify the role of CLR in the invasion process of M. bovis. The results showed that the optimal conditions for M. bovis to invade non-phagocytic cells were a multiplicity of infection (MOI) of 1000 and an optimal invasion time of 4 h. All three strains of M. bovis have the ability to invade the four types of non-phagocytic cells, yet their invasion abilities vary significantly. Observations from transmission electron microscopy further confirmed that at 120 min post-infection, PG45 had successfully invaded EBL cells and was present within endocytic vesicles. It is noteworthy that almost all PG45 successfully escaped from the endocytic vesicles after 240 min of infection had passed. Through chemical inhibition experiments and CLR protein knockdown experiments, it was found that when the CDE and lipid raft pathways were blocked or CLR protein expression was reduced, the invasion rates of PG45, 07801, and 08M in MDBK, EBL, EBTr, and BT cells were significantly decreased (p < 0.05). The above results indicate that M. bovis can invade all types of non-phagocytic cells through endocytic pathways involving CDE (clathrin-dependent endocytosis) or lipid raft-mediated endocytosis, and possesses the ability to escape from phagosomes. Full article

This study aimed to provide experimental support for the prevention and treatment of Pseudomonas aeruginosa infections and to elucidate the epidemiological distribution of resistance and virulence genes of Pseudomonas aeruginosa from mastitis in dairy cows in the northern part of Jiangsu Province and their relationship with the biofilm-forming ability of the strains. Mastitis presents a significant challenge within dairy farming, adversely impacting the health of dairy cows and precipitating substantial economic losses in milk production. In this study, Pseudomonas aeruginosa (PA) was isolated and identified from mastitis milk samples in Jiangsu Province, China. In order to characterize the isolates, multilocus sequence typing (MLST), drug resistance phenotypes, virulence genes, and biofilm formations were detected. The isolation and identification of pathogenic bacteria from 168 clinical mastitis milk samples using 16S rRNA and PCR revealed 63 strains of Pseudomonas aeruginosa, which were determined to be highly homologous according to phylogenetic tree analysis. In addition, the MLST indicated five major ST types, namely ST277, ST450, ST571, ST641, and ST463. The susceptibility to 10 antimicrobials was determined, and it was found that 63 strains of Pseudomonas aeruginosa did not have a strong resistance to the antimicrobials in general. However, there were differences in the phenotypes’ resistance to antimicrobials among the different ST types. It was also found that the more resistant the strains were to antimicrobials, the lower the carriage of virulence genes detected. The biofilm content was measured using the semi-quantitative crystal violet method. It was found that there were a few strains with medium or strong biofilm-forming abilities. However, the number of virulence genes carried by the 63 strains of Pseudomonas aeruginosa was inversely proportional to the biofilm-forming ability. It was also found that there were significantly more Pseudomonas aeruginosa in the biofilm state than in the planktonic state and that strains with strong biofilm-forming abilities were more resistant to antimicrobials. Full article

Objectives: This study investigated metabolic changes associated with bovine leukemia virus (BLV) infection in dairy cows, focusing on pre-parturition alterations. Methods: Metabolite identification in serum and urine samples was performed using a targeted metabolomics method, employing the TMIC Prime kit in combination with flow injection analysis and liquid chromatography–tandem mass spectrometry. Results: Of 145 cows examined, 42 (28.9%) were BLV-seropositive. Around 38% of infected cows showed high somatic cell counts indicative of subclinical mastitis, with 15 experiencing additional health issues such as ketosis, milk fever, and lameness. Despite these conditions, no significant differences in milk yield or composition were observed between the infected and control groups. Metabolomic analysis conducted at −8 and −4 weeks prepartum revealed significant metabolic differences between BLV-infected and healthy cows. At −8 weeks, 30 serum metabolites were altered, including sphingomyelins, lysophosphatidylcholines, amino acids, and acylcarnitines, suggesting disruptions in membrane integrity, energy metabolism, and immune function indicative of early neoplastic transformations. By −4 weeks, the number of altered metabolites decreased to 17, continuing to reflect metabolic disruptions in cows with leukemia. Multivariate analysis highlighted distinct metabolic profiles between infected and control cows, identifying key discriminating metabolites such as choline, aspartic acid, phenylalanine, and arginine. Urine metabolomics revealed significant prepartum shifts in metabolites related to glucose, asymmetric dimethylarginine, and pyruvic acid, among others. Conclusions: The research confirmed metabolomics’ efficacy in defining a BLV infection metabolic profile, elucidating leukosis-associated metabolic disruptions. This approach facilitates the identification of BLV-infected cows and enhances understanding of infection pathophysiology, providing a foundation for advanced management and intervention strategies in dairy herds. The study underscores the profound impact of leukosis on metabolic processes and highlights urine metabolomics’ utility in non-invasively detecting BLV infection, offering the potential for improved herd health management. Full article

Mastitis is a disease that is considered an obstacle in dairy farming. Some methods of diagnosing mastitis have been used effectively over the years, but with an associated relative cost that reduces the producer’s profit. In this context, this sector needs tools that offer an early, safe, and non-invasive diagnosis and that direct the producer to apply resources to confirm the clinical picture, minimizing the cost of monitoring the herd. The objective of this study was to develop a predictive methodology based on sequential knowledge transfer for the automatic detection of bovine subclinical mastitis using computer vision. The image bank used in this research consisted of 165 images, each with a resolution of 360 × 360 pixels, sourced from a database of 55 animals diagnosed with subclinical mastitis, all of which were not exhibiting clinical symptoms at the time of imaging. The images utilized in the sequential learning transfer were those of MammoTherm, which is used for the detection of breast cancer in women. The optimized model demonstrated the most optimal network performance, achieving 92.1% accuracy, in comparison to the model with manual search (86.1%). The proposed predictive methodologies, based on knowledge transfer, were effective in accurately classifying the images. This significantly enhanced the automatic detection of both healthy animals and those diagnosed with subclinical mastitis using thermal images of the udders of dairy cows. Full article

Background: Pseudomonas aeruginosa is a pathogen that causes infections in animals and humans, with veterinary implications including ear infections in dogs, respiratory diseases in cats, and mastitis in ruminants. In humans, it causes severe hospital-acquired infections, particularly in immunosuppressed patients. This study aimed to identify and assess the prevalence of specific virulence factors in Pseudomonas aeruginosa isolates. Methods: We analyzed 98 Pseudomonas aeruginosa isolates from various animal samples (dogs, cats, ruminants, fowl) from northeastern Poland in 2019–2022 for virulence-related genes (toxA, exoU, exoT, exoS, lasB, plcN, plcH, pldA, aprA, gacA, algD, pelA, endA, and oprF) by PCR and assessed biofilm formation at 48 and 72 h. Genomic diversity was assessed by ERIC-PCR. Results: The obtained results showed that all strains harbored the pelA gene (100%), while the lowest prevalence was found for pldA (24%) and exoU (36%). Regardless of the animal species, strong biofilm forming ability was prevalent among the strains after both 48 h (75%) and 72 h (74%). We obtained as many as 87 different genotyping profiles, where the dominant one was profile ERIC-48, observed in four strains. Conclusions: No correlation was found between presence or absence of determined genes and the nature of infection. Similarly, no correlation was found between biofilm-forming genes and biofilm strength. The high genetic diversity indicates challenges for effective prevention, emphasizing the need for ongoing monitoring and research. Full article

Staphylococcus aureus is well known to be the primary causal agent of clinical or subclinical mastitis in dairy sheep. The production of virulence factors allows S. aureus strains to cause mastitis. In the present study, 96 strains isolated from dairy sheep farms used for the production of autologous vaccines were tested for enterotoxin and hemolysin genes by PCR. In addition, 14 strains isolated from half udders of ewes with subclinical mastitis belonging to a single farm were also tested for the same genes. The phylogenetic trees were constructed, and spatial analysis was performed. Overall, 20 gene patterns were identified, but 43.64% of the tested strains showed the same profile (sec+, sel+, hla+, hld+, hlgAC+). Considering only the enterotoxin genes, four profiles were identified while the evaluation of the hemolysin genes revealed the presence of 12 gene patterns. In the farm with subclinical mastitis, six gene profiles were found. Spatial analysis of the isolated strains and their virulence genes did not show a specific pattern. The present study highlights the importance of identifying and analyzing virulence genes of S. aureus strains involved in dairy sheep mastitis, and the presence of different strains in the same farm. Full article

Clostridioides difficile currently constitutes a major pathogen of the gastrointestinal tract, which poses a significant growing burden on medicine and veterinary medicine in many regions. A farm was assessed (feed table, silage pit, and feces (healthy animals, emaciated animals, and animals with mastitis)) for the presence of C. difficile toxins using the PCR method and for the microbiome in cow feed and feces using NGS technology, one month apart. C. difficile toxin A and binary toxin were detected in feed samples. C. difficile toxin genes were found in the feces of sick animals two to three times more often than in healthy animals. Analysis of the microbial community of cow feces revealed that, during the month, the animals experienced major changes in the community structure associated with the accumulation of pathogenic bacteria, in particular Paeniclostridium sp., as well as with the development of methanogenic archaea of the Methanobacteriaceae and associated microorganisms (Lachnospiraceae and Anaerovoracaceae), which may speak of a decrease in feed efficiency and, subsequently, animal productivity. Thus, it seems likely that C. difficile enters the gastrointestinal tract of animals through feed, while animals weakened by diseases are more sensitive to the reproduction of pathogens in the GIT due to a weakened organism. Full article

This study aimed to study the potential effects of climatic conditions prevalent at the locations of sheep farms in the country. The specific objectives were to explore associations between climatic variables and the incidence of four clinical problems in sheep farms and, moreover, to compare these to the health management practices applied in the farms. Our hypothesis was that climatic factors may be associated with the prevalence of diseases in sheep farms; this will provide information regarding potential weather effects, to take into account in the efforts for control of the diseases. Data were obtained during a large cross-sectional investigation performed across Greece involving 325 sheep flocks. Climatic variables prevailing at the location of each farm were derived from ‘The POWER Project’. The annual incidence rate for abortion was 2.0% (95% confidence intervals: 1.9–2.1%), for clinical mastitis 3.9% (3.8–4.0%), for lamb pneumonia 1.4% (1.3–1.4%) and for lamb diarrhoea 7.9% (7.8–8.1%). In multivariable analyses, climatic variables emerged as significant predictors for abortion—high annual precipitation at the farm location (p = 0.024)—and for lamb diarrhoea—high average annual temperature range at the farm location (p < 0.0001)—but not for clinical mastitis or lamb pneumonia. The potential effects of climatic variables were found to be more important in lambs than in adult animals. Future studies may focus on how variations in temperature and precipitation can be translated into on-farm metrics to understand the impacts on sheep health and welfare. Full article

Meloxicam is a non-steroidal anti-inflammatory in the oxicam group. It has been extensively used in human and veterinary medicine for their anti-inflammatory, analgesic and antipyretic activities. Meloxicam has shown high therapeutic potential for disorders such as osteoarthritis, musculoskeletal disorder, acute respiratory infection, puerperal septicemia, mastitis and mastitis–metritis–agalactia syndrome. Although meloxicam pharmacokinetic has been described for numerous species, no paper summarizes the existing literature on this field. Thus, the aim of this review was to carry out a review of the literature on the pharmacokinetics of meloxicam in different animal species and gather the data in a single review article. A comprehensive review of the available literature in the PubMed, Web of Science and Scopus databases was performed. Meloxicam shows good bioavailability after oral and parenteral administration in most animal species (85–95%), with the lowest values in sheep after oral administration. It presents a rapid distribution with a small volume of distribution, which can be attributed to relatively high ionization state of meloxicam at physiological pH and its high plasma protein binding (close to 99%). It is extensively metabolized in the liver in several inactive polar metabolites, which are excreted, like unchanged meloxicam in urine and feces. Meloxicam also shows a long elimination half-life and low clearance. Full article

Mycoplasma bovis is a globally significant pathogen of cattle associated with a wide range of clinical syndromes, including respiratory disease, mastitis, arthritis, otitis, and reproductive failure. Since its detection in Ireland in 1994, M. bovis has become a significant contributor to morbidity and mortality in Irish cattle. This study aimed to investigate herd-level risk factors associated with M. bovis seropositivity in replacement dairy heifers, using data from 105 Irish dairy herds. Ten heifers per herd were sampled on three occasions: spring 2018, spring 2019, and autumn 2019. Seropositivity was evaluated using two thresholds: ≥1 positive heifer (Model ≥ 1POS) and ≥3 positive heifers (Model ≥ 3POS). M. bovis seropositivity varied over time, with at least one positive heifer in 50.4% (95% confidence interval (CI): 40.5–60.3) of herds in spring 2018, 35.2% (95% CI: 26.2–45.1) in spring 2019, and 45.7% (95% CI: 36.0–55.7) in autumn 2019. Herds with three or more positive heifers increased from 31.4% (95%CI: 22.7–41.2) in spring 2018 to 42.9% (95% CI: 33.2–52.9) by autumn 2019. Risk factors for M. bovis seropositivity included the purchase of cattle, which significantly raised the odds of seropositivity across multiple visit periods (Model ≥ 1POS: Odds ratio (OR) 3.84, p = 0.02; Model ≥ 3POS: OR 3.69, p = 0.02). Managing more than three land parcels, housing heifer calves separately from bull calves, and sharing airspace between calves and older animals also increased seropositivity risks. Conversely, more colostrum feeds reduced the risk of seropositivity (Model ≥ 1POS: OR 0.81, p = 0.05), while colostrum quality assessment and feeding waste milk showed a trend toward increased risk. These findings suggest the importance of robust biosecurity measures, including limiting cattle purchases, improving calf management, and enhancing colostrum feeding practices, to control the spread of M. bovis. This study provides valuable insights into the epidemiology of M. bovis in Irish dairy herds, emphasising the need for targeted biosecurity and surveillance to safeguard herd productivity. Full article

Background and aims: Mastitis is one of the main complications during breastfeeding and contributes to the cessation of breastfeeding. However, the etiopathogenesis and diagnosis of mastitis are complex and not yet well defined. We aimed to identify metabolic and lipidic changes in human milk during acute and subacute mastitis in order to detect potential biomarkers of mastitis. Methods: We conducted a pilot case–control study including 14 breastfeeding women with acute mastitis, 32 with subacute mastitis symptoms, and 19 without any mastitis symptoms (control). Milk samples were collected and analyzed by proton nuclear magnetic resonance (H-NMR) for metabolomics analysis. To assess the association between the significant metabolites and lipids and the development of acute and subacute mastitis, multi-adjusted logistic regression models were developed. Results: The NMR-based metabolomics approach was able to identify and quantify a total of 40 metabolites in breast milk samples. After adjusting for confounding variables, acute mastitis was significantly associated with acetate (OR 3.9 IC 1.4–10.8), total cholesterol (OR 14 CI 3.2–62), esterified cholesterol (OR 3.3 CI 1.9–5.8), and sphingomyelin (OR 2.6 CI 1.2–5.8). The other metabolites presented weak association (OR < 2.5). Subacute mastitis was significantly associated with glutamine, lysophosphatidylcholine, phosphatidylcholine, plasmalogen, and total polyunsaturated fatty acids, but only cholesterol showed a strong association (OR > 2.5) with an OR of 2.6 (IC 1.1–6.6). Conclusions: Metabolic alteration in breast milk occurs during a process of both acute and subacute mastitis. Acetate, esterified cholesterol, lysophostidylcholine, and polyunsaturated fatty acids increased in both acute and subacute mastitis. However, according to the multi-adjusted regression logistic models, the candidate biomarkers for acute and subacute mastitis are cholesterol, lysophosphatidylcoholine, phosphatidylcholine, plasmalogen, and polyunsaturated fatty acids. Full article

Economic, social, and environmental sustainability are the results of efforts aiming to improve all aspects of milk production, respecting animal welfare and improving herd health. An epidemiological study was designed to assess the role of contagious pathogens (S. aureus and S. agalactiae) in a cohort of 120 dairy herds located in the southern regions of Italy. Milk quality was assessed using certified methods, and the prevalence of mastitis pathogens in bulk tank milk was determined using quantitative polymerase chain reaction. Welfare scores were assessed using a scoring card that has more than 100 items, including animal-based measurements. Statistical analyses were performed using general lineal model and logistic regression procedures. The results showed that S. aureus had a significant negative effect on the amount of milk nutrients delivered to the dairy plant, and on the level of welfare, whereas the presence of S. agalactiae did not show any significant association. The major risk factors associated with the presence of S. aureus were also identified to help prioritize control programs. These results support the “One Sustainability” approach, implying that an increase in animal productivity is related to the improvement of animal health and welfare and potentially leading to the mitigation of greenhouse gas emissions. Full article

Since the development of dairy farming, bovine mastitis has been a problem plaguing the whole industry, which has led to a decrease in milk production, a reduction in dairy product quality, and an increase in costs. The use of antibiotics to treat mastitis can cause a series of problems, which can bring a series of harm to the animal itself, such as the development of bacterial resistance and dramatic changes in the gut flora. However, the in vivo and in vitro antibacterial activity of yak Interleukin-22 (IL-22) and its application in mastitis caused by Staphylococcus aureus have not been reported. In this study, the mammary gland-specific expression plasmid pLF-IL22 of the yak IL-22 gene was constructed and expressed in MAC-T cells and mammary tissue of postpartum female mice. The coding region of the IL-22 gene in yaks is 573 bp, which can encode 190 amino acids, and the homology difference in the IL-22 gene in yaks is less than 30%, which indicates certain conservation. IL-22 is a hydrophilic protein with a total positive charge of four, the presence of a signal peptide, and the absence of a transmembrane domain. Sufficient expression of IL-22 effectively inhibited the high expression of inflammatory factors caused by Staphylococcus aureus, reduced the symptoms of mammary gland histopathology, and alleviated mastitis. Under the action of IL-22, the intestinal flora of mastitis mice also changed, the abundance of intestinal Bacilli, Prevotellaceae, and Alloprevotella in mice increased after treatment, and the pathogenic bacteria decreased. These findings provide new insights into the potential application of the yak IL-22 gene in the treatment of bovine mastitis in the future. Full article

Objective: The study aimed to use the systemic lupus erythematosus risk probability index (SLERPI) to assess if patients with idiopathic granulomatous mastitis (IGM) meet the criteria for systemic lupus erythematosus (SLE). Methods: A total of 62 patients with IGM and 55 age- and sex-matched healthy controls (HC) were enrolled. The study included patients who were over 18 years old and had been diagnosed with IGM using a true-cut biopsy. The participants’ demographic, clinical, and laboratory data were recorded in detail. The presence of autoantibodies, such as RF, CCP, C3, C4, ANA, ENA profile, and Anti-dsDNA was documented. For the detection of SLE in IGM patients, we used the SLERPI (SLE risk probability index). Results: A total of 62 patients diagnosed with idiopathic granulomatous mastitis (age 35.22 ± 8.34, BMI 27.15 ± 3.41) were compared to 55 healthy controls (age 32.54 ± 8.67, BMI 26.97 ± 3.54). The present study assessed the performance of SLERPI in IGM, and SLERPI positivity was observed in 12 out of 62 (19.4%) IGM patients. There was a significant difference in arthritis and ANA levels in the SLERPI subgroups (p < 001). Conclusions: The SLERPI index can be utilized to identify patients suspected of having systemic lupus erythematosus (SLE) in the IGM cohort. Full article

The study aimed to evaluate interleukin-8 (IL-8) as a biomarker for udder inflammation in dairy cows and to explore its associations with various metabolic parameters indicative of systemic inflammation and metabolic dysregulation. Dairy cows (multiparous) were categorized into five somatic cell count (SCC) classes: Class I (<100,000 cells/mL; n = 45), Class II (100,000–200,000 cells/mL; n = 62), Class III (201,000–400,000 cells/mL; n = 52), Class IV (401,000–1,000,000 cells/mL; n = 73), and Class V (>1,000,000 cells/mL; n = 56). The study quantified IL-8 levels and analyzed their correlations with NEFAs (non-esterified fatty acids), BHBA (beta-hydroxybutyrate), GGTP (gamma-glutamyltransferase), and AspAT (aspartate aminotransferase). IL-8 concentrations demonstrated a significant and progressive increase across the SCC classes, establishing a strong positive correlation with SCC (p < 0.01). Additionally, IL-8 levels exhibited positive correlations with GGTP (p < 0.01) and AspAT (p < 0.01), indicating that elevated IL-8 is associated with increased hepatic enzyme activities and potential liver dysfunction. Furthermore, IL-8 showed significant positive correlations with NEFAs (p < 0.01) and BHBA (p < 0.05), linking higher IL-8 levels to metabolic disturbances such as ketosis and negative energy balance. Variations in metabolic parameters, including NEFAs, BHBA, GGTP, and AspAT, across the SCC classes underscored the association between elevated SCC levels and metabolic dysregulation in dairy cows. These findings highlight the interrelated nature of the inflammatory responses and metabolic disturbances in dairy cattle, emphasizing that an elevated SCC not only signifies udder inflammation but also correlates with systemic metabolic alterations indicative of ketosis and liver damage. Full article