Mastitis In Cows Research Articles

Resistance to antimicrobial preparations of Enterococcus isolated from milk during infectious mastitis in cows

For successful pharmacotherapy of animals, it is important to identify species of Enterococcus faecalis pathogens isolated from milk in infectious mastitis of cows, analyze the antibiogram and interpret the results, and laboratory control over the mechanisms of antibiotic resistance. This is necessary for veterinarians to rationally select antibacterial drugs and predict their clinical effectiveness. The purpose of the study was to study the resistance to antimicrobial drugs of Enterococcus faecalis bacteria isolated from milk in infectious mastitis of cows. In the period from 2021 to 2022, 100 strains of microorganisms were isolated from the mastitis milk of cows. The obtained strains were identified as gram-negative bacteria in 32% of isolation cases, gram-positive bacteria - 68%, of which 14% were Enterococcus faecalis. When interpreting the antibiogram, most isolates of Enterococcus faecalis are sensitive to tetracycline in 21.4% of isolation cases, ampicillin, amoxicillin in 100%. It was noted resistant to tetracycline in 78.6% of cases of isolation, gentamicin, cephalexin, cefotaxime, erythromycin, clindamycin, lincomycin, tobramycin, ceftriaxone and streptomycin in 100%. Antibiotic resistance correlates with the clinical failure of antimicrobials in veterinary medicine. Multi-resistance of Enterococcus faecalis to various groups of antibacterial agents leads to limited use of antibiotics, which significantly reduces the possibilities of therapy and affects the economic condition of agriculture.

Risk Factors of Mastitis and Antibiotic Susceptibility of Staphylococcus aureus and Escherichia coli isolated from Cows Kept by Farmers in Githunguri Sub-County, Kenya

Mastitis poses a major challenge in dairy cattle farming as it leads to production and economic losses. Some mastitis causing bacteria have shown resistance to some antibiotic and the risk factors associated with the antimicrobial resistance (AMR) are not well understood. The current study assessed the prevalence and risk factors associated with occurrence of mastitis in dairy cows kept by small-holder farmers in Githunguri Sub-County, Kenya. Further, susceptibility of the isolated Staphylococcus aureus and Escherichia coli to commonly used antibiotics was evaluated. The study design was cross sectional where 91 milk samples from 40 farms were sampled from two wards in the study area. Structured questionnaires were used to assess risk factors of mastitis. The milk obtained from lactating cows was first subjected to California mastitis test (CMT) and then taken to microbiology laboratory for isolation and identification of Staphylococcus aureus and Escherichia coli using standard bacteriological tests. Antibiotics sensitivity of the isolated bacteria was examined using disc diffusion method. Based on CMT, the overall prevalence of mastitis was 50.5%. The prevalence of mastitis was associated (p<0.05) with hygiene levels, being highest (69.2%) in the dairy cattle whose udder and leg hygiene were dirty. Highest prevalence of mastitis (p<0.05) was found in cows who were not milked regularly (52.4%) compared to those who were milked regularly (47.6%) (p<0.05). Cows which were cleaned using bore hole water had higher prevalence (53.3%) of mastitis compared to those cleaned using tap water (46.7%) (p<0.05). Cows that produced between 21-30 liters of milk per day had the highest prevalence (66.7%) of mastitis, while those producing between over 30 liters milk per day had lower prevalence (25%) (p<0.05). The prevalence of S. aureus and E. coli were 30.8% and 12.1%, respectively. Staphylococcus aureus isolates showed varied resistance to all the tested antibiotics with the highest resistance being against Oxytetracycline (57.7%) and Tetracycline (38.5%) but were sensitive to Vancomycin (100%), Ampicillin (100%), Chloramphenicol (96.2%), Penicillin (92.3%) and Gentamycin (92.3%). All the Escherichia coli isolates were sensitive to Chloramphenicol, Kanamycin, Gentamycin and Oxytetracycline but were resistant to Ampicillin (88.9%) and Vancomycin (88.9%) amongst other antibiotics. In conclusion, half of the sampled cows had mastitis whose risk factors was associated with poor hygiene and irregular milking of the cows. The isolated bacteria showed varied resistance to commonly used antibiotics. To reduce the prevalence of the mastitis and AMR, there is need for extension service workers to train farmers on improved management of the mastitis.

Comparative Analysis of Methods for Somatic Cell Counting in Cow's Milk and Relationship between Somatic Cell Count and Occurrence of Intramammary Bacteria.

The aim of this study was to compare three on-farm commercial methods for the indirect detection of subclinical mastitis in dairy cows: the California mastitis test (CMT), the Porta side somatic cell count milk test (Porta SCC), and the DeLaval cell counter (DCC), with the Fossomatic cell count (FSCC), and to evaluate the relationship between the determined somatic cell count SCC and the occurrence of intramammary pathogens in the milk of dairy cows. A total of 284 sensory unchanged mixed milk samples, collected during the milking on a dairy farm, were analyzed in this study for somatic cell counts by the mentioned on-farm tests. Quarter milk samples (n = 583) from all the selected cows were cultured. The agreement, sensitivity, and specificity of the three indirect commercial diagnostic tests (the CMT, the Porta SCC, and the DeLaval cell counter) were calculated, and the FSCC was used as the gold standard. The results were analyzed statistically using the Pearson correlation test and the paired t-test. The CMT matched with the FSCC in 83.1% of the samples, with the Porta SCC in 80.6%, and with the DCC in 80.3% of the samples. The sensitivity and specificity reached 81.0% and 92.9% for the CMT, 79.4% and 90.7% for the Porta SCC, and 75.8% and 97.5% for the DCC, respectively. The correlation between the FSCC and the Porta SCC was 0.86 (p < 0.0001), and between the FSCC and the DCC, it was 0.92 (p < 0.0001). The differences between them were insignificant. Bacteria were detected in 130 (22.3%) quarter milk samples. The most prevalent bacteria were Enterococcus spp. (36.2%), followed by E. coli (20%), coagulase-negative staphylococci (13.1%), A. viridans (9.2%), Streptococcus spp. (9.2%), Proteus spp. (6.2%), and S. intermedius (3.9%). Contagious isolates (S. aureus) were detected in 3 quarter milk samples (2.3%). The agreement between the individual tests and the microbiological culture was as follows: 69.2% for the CMT; 73.7% for the Porta SCC; 71.6% for the DCC; and 76.5% for the FSCC. Higher SCCs were detected in the milk samples contaminated with bacteria than in the healthy milk (p < 0.001). No significance was found between the presence of individual species of intramammary pathogens and the different levels of SCCs. Based on the results, bacteria are the predominant cause of subclinical mastitis. The increased SCC of some milk samples with no presence of bacteria meant that the increase could have been caused by numerous other agents (viruses, fungi, or algae) or factors for mastitis in the dairy industry.

Putting research to the test: Implementing selective dry cow therapy on farms across New York State

Selective dry cow therapy (SDCT) has been shown to be an ef­fective way of using antimicrobials judiciously on dairy farms while decreasing treatment costs and maintaining herd health. However, adoption of the practice has been slow in the U.S. In order to improve the adoption of this practice in New York State, we formed a team of veterinarians to help interested dairy producers and their herd veterinarians to implement SDCT successfully. Not all farms are a good fit for SDCT. An in-depth discussion between the herd veterinarian and farm stakeholders before adoption is necessary. This discussion should include current practices, data available to make the selection process, best practices for dry off and dry-pen man­agement, and how to monitor progress going forward. Our team enrolled 24 farms over the course of a year. Seventeen out of 24 farms are still using SDCT at the time of publishing. A variety of SDCT methods were used, and on average, herds decreased dry cow antibiotic use by 53%. The metrics we used to monitor herd infection dynamics before and after SDCT included aver­age monthly somatic cell count, fresh cow mastitis incidence, average herd prevalence of a high first test, average herd preva­lence of subclinical infection, average new infection risk, and cure risk. For all but a few herds, 95% confidence intervals overlapped for all outcomes before and after starting SDCT and differences were relatively small. In our experience, SDCT, if employed on the right farm, is an effective way to use antibiot­ics judiciously at dry off without disrupting herd health.

Ultrashort lipo-tetrapeptide with potent antibacterial activity and local therapeutic effect against Staphylococcus aureus

Mastitis in dairy cows is a common infectious disease on dairy farms and a major danger to the dairy industry. The harmful bacteria with the greatest clinical isolation rate is Staphylococcus aureus. As a result, bacterial mastitis in dairy cows can lead to decreased milk output, quality, and costs. Traditional antibiotics are currently used to treat mastitis in dairy cows. Nonetheless, long-term usage of high doses of antibiotics increases the risk of the establishment of drug-resistant strains, and the problem of drug residues is becoming more prevalent. The antibacterial effects of varying molecular side chain length lipopeptides on Staphylococcus aureus ATCC25923 and GS1311 were investigated using five tetrapeptide ultrashort lipopeptides developed and synthesized in this study. To evaluate the application value of the synthesized lipopeptides in the prevention and treatment of mastitis, the lipopeptides with the best antibacterial action were chosen for safety testing and a mouse mastitis model treatment test. The results revealed that three of the lipopeptides produced have strong antibacterial properties. Within the drug's safe concentration range, C16KGGK has an excellent antibacterial action and can have a therapeutic influence on mastitis induced by Staphylococcus aureus infection in mice. The findings of this study can be used to develop new antibacterial medications and their therapeutic application in the treatment of mastitis in dairy cows.

Phytosphingosine alleviates Staphylococcus aureus-induced mastitis by inhibiting inflammatory responses and improving the blood-milk barrier in mice

Mastitis is one of the common diseases in dairy cows which threatens the health of cows and impacts on economic benefits seriously. Recent studies have been showed that Subacute Ruminal Acidosis (SARA) increased the susceptibility of cow mastitis. SARA leads the disturbance of the rumen microbiota, and the rumen bacterial disordered community is an important endogenous factor of cow mastitis. That is to say, cows which suffer from SARA have a disordered rumen microbiota, a prolonged decline in ruminal PH and a high level of lipopolysaccharide (LPS) in the rumen, blood. Therefore, ruminal metabolism is closely related to the rumen microbiota. However, the specific mechanism of SARA and mastitis still not clear. We found an intestinal metabolite according to the metabonomics, which is correlated to inflammation. Phytophingosine (PS), a product from rumen fluid and milk of the cows which suffer from SARA and mastitis. It has the effect of killing bacteria and anti-inflammatory. Emerging evidences indicate that PS can alleviate inflammatory diseases. However, how PS affects mastitis is largely unknown. In this study, we explored the concrete role of PS on Staphylococcus aureus (S. aureus) -induced mastitis in mice. We found that PS obviously decreased the level of the proinflammatory cytokines. Meanwhile, PS also significantly relieved the mammary gland inflammation caused by S. aureus and restored the function of the blood-milk barrier. Here, we showed that PS increased the expression of the classic Tight-junctions (TJs) proteins including ZO-1, Occludin and Claudin-3. Moreover, PS improves S. aureus-induced mastitis by inhibiting the activation of the NF-κB and NLRP3 signaling pathways. These data indicated that PS relieved S. aureus-induced mastitis effectively. This also provides a reference for exploring the correlation between the intestinal metabolism and inflammation.

Effectiveness of a new means of etiotropic therapy of mastits in cows during the lactation period

The aim: is to study the therapeutic effectiveness of the new veterinary medicinal product Revozyn RTU 400 mg/ml (suspension for injections), manufactured by Eurovet Animal Health B.V. (Netherlands), in the treatment of acute (clinical) and hidden (subclinical) mastitis in cows during lactation.&#x0D; Materials and methods. The research was conducted on dairy cows of the Simmental breed with a milk productivity of 6000-6500 kg of milk per lactation (F "Pchany-Denkovich", Pchany village, Stryi district, Lviv region). To confirm the diagnosis of "acute mastitis" and to identify cows with hidden (subclinical) mastitis, as well as to establish the effectiveness of the researched drug after treatment, a sample was taken with the California Mastitis Test (CMT), manufactured by Bayer Animal Health GmbH, Germany. For bacteriological research, milk samples were taken from the affected quarters of the mammary gland (1 sample from each cow) in compliance with generally accepted sanitary rules. The sensitivity of bacterial isolates to the drug was determined by diffusion in agar using standard discs with benzylpenicillin.&#x0D; Results. A clinical examination of 127 Simmental dairy cows of different periods of lactation was carried out. During the clinical-diagnostic examination of animals, 8 cows with clinically pronounced, acute course of mastitis were found. According to the nature of the exudate in 3 cows, mastitis was serous, in 5 cows it was purulent-catarrhal. For serous mastitis, the CM test gave a positive result – thickening, the milk solution looks like a gel. In case of purulent catarrh, a sample with the CMT gave a strongly positive result – the mixture thickened, the gel took on a certain shape and became very viscous. The CMT revealed 12 cows with suspected latent mastitis. Representatives of opportunistic microflora – Streptococcus agalactiae, Staphylococcus aureus, and Escherichia coli bacteria were isolated and identified from mastitis milk. The summarized results of the clinical trial of the drugs Revozyn RTU 400 mg/ml and Procillin® 30 % on cows suffering from the clinical form of mastitis were as follows. On the 10th day of the experiment, a milk sample with the California mastitis test showed that all milk samples from cows of both groups (with the exception of one milk sample from a cow from the control group) gave a negative result (the solution remained liquid, blue or gray and homogeneous, without clots). Taking into account the results of the CMT and the number of somatic cells in the milk after the therapy, the therapeutic effectiveness of the veterinary medicinal product Revozyn RTU 400 mg/ml in the treatment of various forms of mastitis in lactating cows was 100 %, and the one of the comparative drug Procillin® 30 % was 83.3 % .&#x0D; Conclusions. A clinical study of the veterinary medicinal product Revozyn RTU 400 mg/ml, suspension for injections, manufactured by Eurovet Animal Health B.V. (Netherlands) established its effectiveness in the dosage, recommended by the manufacturer, in the treatment of clinical and subclinical mastitis in lactating cows, caused by microorganisms sensitive to benzylpenicillin. In terms of therapeutic effectiveness, the drug Revozyn RTU 400 mg/ml was not inferior to the comparative drug Procillin® 30 % in its dosage form and active substance when used in the treatment of various forms of mastitis in lactating cows

The effectiveness of the use of biotinylated derivative of oxidized dextran in the prevention of subclinical mastitis of cows

Prevention of cow mastitis remains an urgent problem in veterinary medicine. The majority of subclinical mastitis resulting from a violation of the milking regime, in the absence of adequate therapy, turn into a clinical form, complicated by the involvement of representatives of conditionally pathogenic microflora in the process. To prevent the development of such complications, agents that activate the cellular and humoral immunity system are used.The article presents the results of a study of the use of biotinylated derivative of oxidized dextran (DOD) in the prevention of subclinical mastitis of cows.The data obtained in the course of the work showed a high preventive effectiveness of DOD. In the experimental group, a dynamic decrease of somatic cells by 16.85% relative to the control was observed on day 4-5. Starting from the second administration of the drug, stable low values of somatic cells were observed in the experimental group, whereas in the control group animals were identified that respond positively to Kenotest, which together with an increase in somatic cells indicates the development of latent (subclinical) mastitis.

Resistance to antimicrobial drugs of staphylococci isolated from milk in infectious mastitis of cows

Аnalysis of antibiograms and interpretation of the results, laboratory monitoring of the mechanisms of antibiotic resistance of Staphylococcus aureus isolated from milk in infectious mastitis of cows is necessary for successful pharmacotherapy of animals.The aim of the study was to study the antibiotic resistance of Staphylococcus aureus bacteria isolated from milk in infectious mastitis of cows.In the period from 2021 to 2022, 100 strains of microorganisms were isolated from milk in infectious mastitis of cows. The strains were identified as gram-positive Staphylococcus aureus - 16%.When interpreting the antibiogram, it was found that strains of Staphylococcus aureus are sensitive to cephalosporins, aminoglycosides, lincosamides, tetracyclines in 100% of isolation cases, and to benzylpenicillins - 81%. and also resistant.

The Relationship between Reticuloruminal Temperature, Reticuloruminal pH, Cow Activity, and Clinical Mastitis in Dairy Cows

We hypothesized that reticuloruminal temperature, pH as well as cow activity can be used as parameters for the early diagnosis of clinical mastitis in dairy cows. Therefore, we aimed to detect the relationship between these factors and the disease. We randomly selected cows with clinical mastitis and clinically healthy cows (HG) out of 600 milking cows. We recorded the following parameters during the experiment: reticulorumen temperature (RR temp.), reticulorumen pH (RR pH), and cow activity. We used smaXtec boluses (smaXtec animal care technology®, Graz, Austria). In this investigation, reticulorumen data obtained seven days before diagnosis were compared to HG data from the same time period. CM cows were observed on the same days as the healthy cows. The healthy group’s RR pH was 7.32% higher than that of cows with CM. Reticulorumen temperature was also 1.25% higher in the CM group than in the control group. The healthy group had a higher average value for walking activity, which was 17.37% higher than the CM group. The data of reticulorumen pH changes during 24 h showed that during the day, the pH changed from 5.53 to 5.83 in the CM group. By contrast, pH changed from 6.05 to 6.31 in the control group. The lowest reticulorumen pH in the CM group was detected on the third day before diagnosis, which was 15.76% lower than the highest reticulorumen pH detected on the sixth day before diagnosis. The lowest reticulorumen pH in CM cows was detected at 0 and 1 days before diagnosis and it was 1.45% lower than the highest reticulorumen pH detected on the second day before diagnosis. The lowest walking activity in the CM group was detected 0 days before diagnosis, which was 50.60% lower than on the fifth day before diagnosis. Overall, the results confirmed our hypothesis that reticuloruminal temperature, reticuloruminal pH, and cow activity could be used as parameters for the early diagnosis of clinical mastitis in dairy cows.

Bacteremia in Severe Mastitis of Dairy Cows.

The aim of this cross-sectional study was to investigate the occurrence of bacteremia in severe mastitis cases of dairy cows. Milk and corresponding blood samples of 77 cases of severe mastitis were bacteriologically examined. All samples (milk and blood) were incubated aerobically and anaerobically to also investigate the role of obligate anaerobic microorganisms in addition to aerobic microorganisms in severe mastitis. Bacteremia occurred if identical bacterial strains were isolated from milk and blood samples of the same case. In addition, pathogen shedding was examined, and the data of animals and weather were collected to determine associated factors for the occurrence of bacteremia in severe mastitis. If Gram-negative bacteria were detected in milk samples, a Limulus test (detection of endotoxins) was also performed for corresponding blood samples without the growth of Gram-negative bacteria. In 74 cases (96.1%), microbial growth was detected in aerobically incubated milk samples. The most-frequently isolated bacteria in milk samples were Escherichia (E.) coli (48.9%), Streptococcus (S.) spp. (18.1%), and Klebsiella (K.) spp. (16%). Obligatory anaerobic microorganisms were not isolated. In 72 cases (93.5%) of the aerobically examined blood samples, microbial growth was detected. The most-frequently isolated pathogens in blood samples were non-aureus Staphylococci (NaS) (40.6%) and Bacillus spp. (12.3%). The Limulus test was positive for 60.5% of cases, which means a detection of endotoxins in most blood samples without the growth of Gram-negative bacteria. Bacteremia was confirmed in 12 cases (15.5%) for K. pneumoniae (5/12), E. coli (4/12), S. dysgalactiae (2/12), and S. uberis (1/12). The mortality rate (deceased or culled) was 66.6% for cases with bacteremia and 34.1% for cases without bacteremia. High pathogen shedding and high humidity were associated with the occurrence of bacteremia in severe mastitis.

Bibliographic Synthesis on the Influence of Cow Mastitis on Fresh Milk Quality

Mastitis in lactating cows lead to a decrease in the overall cow production; make milk unfit for human and calf consumption; deteriorate milk quality. However, data are not updated on the influence of mastitis on the physicochemical and microbiological quality of milk. Therefore, the present review was made to highlight the current state of knowledge on prior research on the impact of mastitis on milk quality, and to identify the shortcomings of these studies. Two themes were addressed to achieve this. We started by reviewing the prevalence, aetiology and factors associated with the occurrence of mastitis in the African continent. Then, we compared the variation of chemical components of mastitis milk in several studies. Our analysis shows that subclinical mastitis is predominant in Africa, with most prevalence higher than 50%. The majority of authors (83.33%) claimed that Staphylococci are the main cause of mastitis. The breed (83.33%) and lactation stage (66.66%) were the two most cited factors contributing to the occurrence of mastitis. Data collected on the chemical components of mastitis milk came mostly from studies prior to the year 2000. Several contrary opinions (increase/decrease/no variation) were stated by authors on the variation of chemical components of mastitic milk, specifically on fat, lactose and crude protein contents. Overall, it is challenging, if not impossible, to draw a definitive conclusion about the influence of mastitis on the chemical composition of milk for most chemical parameters, because the data examined in relation to the chemical components of milk with mastitis seem rather inconsistent.

Negatively controlled trial investigating the effects of dry cow therapy on clinical mastitis and culling in multiparous cows

Blanket dry cow therapy (DCT) is a major contributor to overall antibiotic usage on dairy farms in the United States. With low prevalence of intramammary infections at dry-off in US herds today, alternative DCT approaches have been the focus of much research. We hypothesized that complete cessation of DCT [i.e., use of internal teat sealants (ITS) only at dry-off] could be a practical alternative to blanket DCT in well-managed herds. The objective of this negatively controlled clinical trial was to determine the effects of DCT on clinical mastitis (CM) and removal from the herd during the dry period and the first 200 d of the subsequent lactation in multiparous dairy cows treated with only ITS at dry-off. As a secondary objective, we conducted exploratory analysis to identify subpopulations in the herd (based on parity, previous CM history, and dry-period length) where DCT would not affect postcalving udder health, to generate hypotheses about potential alternative selective DCT programs. The study was conducted in a commercial dairy herd in South Dakota from June 2020 to January 2021. Dry-off sessions (n = 43) were scheduled such that all cows at a given session were dried off using ITS alone (ITS only, n = 20 sessions, n = 1,108 cows) or an intramammary DCT product containing 500 mg of cloxacillin (Dry-Clox, Boehringer Ingelheim) followed by ITS (ITS+ABX, n = 23 sessions, n = 1,331 cows). Culling and CM events were recorded by farm workers who were blinded to the treatment status of cows. Hazard ratios (HR) for the effects of the treatment group on CM and removal from the herd were estimated using multivariable Cox proportional hazards, adjusting for the clustered treatment allocation strategy. Risk of removal from the herd during the dry period was lower in ITS+ABX than ITS-only cows (1.1 vs. 2.7%; HR = 0.45; 95% CI: 0.25 to 0.81). Risk of removal from the herd during the first 200 d of lactation was similar in ITS+ABX and ITS-only cows (17.3 vs. 18.0%; HR = 0.98; 95% CI: 0.82 to 1.18). Risk of CM during the first 200 d of lactation was lower in ITS+ABX cows (6.9%; HR = 0.56; 95% CI: 0.41 to 0.76) compared with ITS-only cows (13.4%). The beneficial effects of DCT on CM and removal from the herd were consistently observed across strata of parity, previous CM history, and dry-period length, indicating that no subpopulations could be identified to withhold DCT. The findings from this study indicate that the omission of DCT from the dry-off procedure, when udder health is not taken into consideration, in multiparous cows can have a negative effect on cow health and welfare. Findings from previous research suggest that culture- or algorithm-guided selective dry cow therapy are likely to be safer approaches to improving antibiotic stewardship.

Alternatives to antibiotics for treatment of mastitis in dairy cows.

Mastitis is considered the costliest disease on dairy farms and also adversely affects animal welfare. As treatment (and to a lesser extent prevention) of mastitis rely heavily on antibiotics, there are increasing concerns in veterinary and human medicine regarding development of antimicrobial resistance. Furthermore, with genes conferring resistance being capable of transfer to heterologous strains, reducing resistance in strains of animal origin should have positive impacts on humans. This article briefly reviews potential roles of non-steroidal anti-inflammatory drugs (NSAIDs), herbal medicines, antimicrobial peptides (AMPs), bacteriophages and their lytic enzymes, vaccination and other emerging therapies for prevention and treatment of mastitis in dairy cows. Although many of these approaches currently lack proven therapeutic efficacy, at least some may gradually replace antibiotics, especially as drug-resistant bacteria are proliferating globally.

Health of the dairy herd and indicators of milk quality

Now a lot of attention is paid to the safety and quality of food products. Milk and dairy products are in significant demand among the population and occupy a significant segment in the variety of human food. The content of fat and protein characterize the quality of milk and are of great importance. The cost of raw materials, therefore, the farmer's profit, depends on these indicators. It is impossible to produce a high-quality product from hazardous raw materials. Cattle udder health is an important factor in animal welfare and dairy farm economics. The purpose of the research was to analyze data characterizing the health of dairy cows and milk quality indicators (fat and protein content depending on the month of the year). Collected milk from cows of the farm “Yekaterinoslavsky”, Dnipro city, was studied. Average indicators of fat and protein content per month during 2021 and 2022 are presented. Farm data were analyzed: the proportion of new cases of mastitis in dairy cows per month for 2021 and 2022. The lowest content of fat (3.47–3.65 %) and protein (3.26–3.41 %) in the cow milk is observed in the summer, which is due to the largest amount of milk obtained from cows during this period. It is accepted that the dairy herd is healthy if the proportion of cows with mastitis does not exceed 4 %. This indicator was exceeded only once – in June 2022 (4.45 %). In 2021, the highest rates of mastitis cases were observed in January and December – 2.96 and 3.05 %, respectively. The smallest share of new cases of mastitis was noted in September and November – 1.52 and 0.97 %, respectively. Perhaps this is connected with the mass launch of cows and the dry period. In 2022, the dairy herd increased by more than 100 cows, and the proportion of new cases of mastitis increased. The highest rates of mastitis cases in 2022 were observed in June and July – 4.45 and 3.84 %, respectively. The lowest proportion of new cases of mastitis was noted in August and November – 2.72 and 2.54 %, respectively. In general, the dairy herd of the dairy complex is safe from mastitis, the share of this disease is less than 4 %.

Vancomycin-Resistant Enterococcus spp. Isolated From Mastitic cow’s milk

Vancomycin-Resistant Enterococcus spp. Isolated From Mastitic cow’s milk

Studi Kasus: Jumlah Sel Somatik dan Komposisi Susu dari Sapi Perah Positif Mastitis Subklinis Milik PT. Great Giant Livestock

An increase in the number of somatic cells to more than 400.000 cells/mL and the presence of pathogenic bacteria in the milk during normal lactation are two characteristics of subclinical mastitis. The purpose of this study was to compare subclinical mastitis-positive cows with healthy cows in terms of somatic cells count and milk composition, as well as the relationship between these two variables. Acquire from PT. Great Giant Livestock, a total of 29 fresh milk samples from 9 dairy cows tested positive for subclinical mastitis. The Breed method was used to determine the somatic cell count. Lactoscan was used to count the milk composition including fat, protein, lactose, solid non-fat, total solids, and density. The correlation between the somatic cell count and milk quality was tested using the Rank Spearman and the differences in milk quality between healthy cows and subclinical mastitis-positive cows were analyzed using Mann Whitney U. According to the data, subclinical mastitis-positive cows had more somatic cells than healthy cows. Furthermore, subclinical mastitis-affected cows provide milk of lower quality. Dairy cows with subclinical mastitis and healthy cows had significantly different milk composition (p&lt; 0,05). The correlation between the number of somatic cells and milk composition was highly significant (p&lt; 0,05). Subclinical mastitis-positive cows have a higher number of somatic cell and lower milk composition compared to healthy cows. The somatic cells count has a relationship with the composition of milk.

A high-concentrate diet induces mitochondrial dysfunction by activating the MAPK signaling pathway in the mammary gland of dairy cows

Subacute rumen acidosis can lead to mastitis in dairy cows. Mitochondrial dysfunction is closely related to the inflammatory response. This experiment was conducted to investigate the effects of a high-concentrate diet on mammary gland inflammation and mitochondrial damage in dairy cows. Twelve Holstein dairy cows in mid-lactation were randomly divided into 2 groups and fed a 40% concentrate (low concentrate, LC) diet or a 60% concentrate (high concentrate, HC) diet. Cows were fed individually, and the experiment lasted for 3 wk. After the experiment, mammary gland tissue, blood, and rumen fluid were collected. Compared with the LC diet, the HC diet significantly decreased rumen pH; the pH was <5.6 for more than 3 h. The HC diet also increased the concentration of LPS in the blood (7.17 ± 1.25 µg/mL vs. 12.12 ± 1.26 µg/mL), which indicated that feeding the HC diet successfully induced subacute rumen acidosis. The HC diet also increased the concentration of Ca2+ (34.80 ± 4.23 µg/g vs. 46.87 ± 7.24 µg/g) in the mammary gland and upregulated the expression of inflammatory factors IL-6 (1,128.31 ± 147.53 pg/g vs. 1,538.42 ± 241.38 pg/g), IL-1β (69.67 ± 5.86 pg/g vs. 90.13 ± 4.78 pg/g), and tumor necrosis factor-α (91.99 ± 10.43 pg/g vs. 131.75 ± 17.89 pg/g) in mammary venous blood. The HC diet also increased the activity of myeloperoxidase (0.41 ± 0.05 U/g vs. 0.71 ± 0.11 U/g) and decreased the content of ATP (0.47 ± 0.10 µg/mL vs. 0.32 ± 0.11 µg/mL) in the mammary gland. In addition, phosphorylation of JNK (1.00 ± 0.21 vs. 2.84 ± 0.75), ERK (1.00 ± 0.20 vs. 1.53 ± 0.31), and p38 (1.00 ± 0.13 vs. 1.47 ± 0.41) and protein expression of IL-6 (1.00 ± 0.22 vs. 2.21 ± 0.27) and IL-8 (1.00 ± 0.17 vs. 1.96 ± 0.26) were enhanced in cows of the HC group, indicating that the mitogen-activated protein kinase (MAPK) signaling pathway was activated. Compared with the LC diet, the HC diet reduced the protein expression of mitochondrial biogenesis-related proteins PGC-1α (1.00 ± 0.17 vs. 0.55 ± 0.12), NRF1 (1.00 ± 0.17 vs. 0.60 ± 0.10), TFAM (1.00 ± 0.10 vs. 0.73 ± 0.09), and SIRTI (1.00 ± 0.44 vs. 0.40 ± 0.10). The HC diet promoted mitochondrial fission and inhibited mitochondrial fusion by reducing protein expression of MFN1 (1.00 ± 0.31 vs. 0.49 ± 0.09), MFN2 (1.00 ± 0.19 vs. 0.69 ± 0.13), and OPA1 (1.00 ± 0.08 vs. 0.72 ± 0.07), and by increasing that of DRP1 (1.00 ± 0.09 vs. 1.39 ± 0.10), MFF (1.00 ± 0.15 vs. 1.89 ± 0.12), and TTC1/FIS1 (1.00 ± 0.08 vs. 1.76 ± 0.14), leading to mitochondrial dysfunction. The HC diet increased mitochondrial permeability by upregulating the protein expression of VDAC1 (1.00 ± 0.42 vs. 1.90 ± 0.44), ANT (1.00 ± 0.22 vs. 1.27 ± 0.17), and CYPD (1.00 ± 0.41 vs. 1.82 ± 0.43). Taken together, these results indicated that feeding the HC diet induced mitochondrial damage via the MAPK signaling pathway in the mammary gland of dairy cows.

Biofilm-Producing Ability of Staphylococcus aureus Obtained from Surfaces and Milk of Mastitic Cows

This study was conducted to evaluate the incidence of mastitis in 153 dairy cows and to evaluate the kinetics of adhesion of isolates obtained from surfaces and milk in comparison with the reference strain (RS), CCM 4223. The surfaces of the floor, teat cup, and cow restraints were aseptically swabbed in three replicates (n = 27). Of the total number of infected cows (n = 43), 11 samples were found to be positive for Staphylococcus aureus, 12 samples tested positive for non-aureus staphylococci, 6 samples tested positive for Streptococcus spp., and 11 samples tested positive for other bacteria (Escherichia coli, Pseudomonas spp.) or a mixed infection. The most represented pathogen in milk (11/43) and on surfaces (14/27) was S. aureus. The kinetics of adhesion of the reference strain and isolates of S. aureus on stainless steel surfaces were determined after 3, 6, 9, 12, 24, and 48 h, and 3, 6, 9, 12, and 15 days of incubation. All strains reached counts higher than 5 Log10 CFU/cm2 needed for biofilm formation, except RS (4.40 Log10 CFU/cm2). The isolates of S. aureus revealed a higher capability to form biofilm in comparison with RS during the first 3 h (p &lt; 0.001). Thus, there is a significant difference between the occurrence of S. aureus on monitored surfaces—floor, teat cup, and cow restraints—and the frequency with which mastitis is caused by S. aureus (p &lt; 0.05). This finding raises the possibility that if various surfaces are contaminated by S. aureus, it can result in the formation of biofilm, which is a significant virulence factor.

Antibacterial efficacy of greenly synthesized silver nanoparticles using nanocurcumin and silver nanoparticle gel on bovine mastitis

This study summarizes the synthesis of AgNPs using nanocurcumin as a reducing and stabilizing agent (CurAgNPs). The stability of CurAgNPs after 12 months of storage and their antimicrobial activity against four bacteria causing mastitis in cows were investigated. Ultraviolet—visible (UV–vis) spectroscopy of the dark brownish-red stabilized CurAgNPs solution decating the surface plasmon resonance peak of the sample was observed at 438 nm. Images of the spherical CurAgNPs were obtained using transmission electron microscopy (TEM), which showed a mean particle size distribution of 15–58 nm, with a mean size of 32 nm. The influence of CurAgNPs on four microorganisms that cause mastitis in cows, Streptococcus agalactiae (S. agalactiae), Staphylococcus aureus (S. aureus), Pseudomonas aeruginosa (P. aeruginosa), and Eschericia coli (E. coli), was studied, and the minimum inhibitory concentration (MIC) was from 1.6 to 6.25 ppm. From this, the MBC of CurAgNPs were observed at 3.15 ppm for S. agalactiae, and 6.25 ppm for S. aureus, P. aeruginosa and E. coli, respectively. The formulated homogeneous gel containing 100 ppm CurAgNPs, 1.5% carboxymethyl cellulose (CMC), and distilled water was developed with a viscosity of 141 ± 7.55 cP, pH of 6.72 ± 0.11, and homogenized. The zeta potential of CurAgNPs gel after 6 months of storage is almost constant. In addition, the improved CurAgNPs gel demonstrated significant antimicrobial activity compared with tetracycline at a concentration of 100 ppm.