Mastitis Control Research Articles

Methicillin-resistant Staphylococcus aureus CC22-MRSA-IV as an agent of dairy cow intramammary infections

Methicillin-resistant S. aureus (MRSA) lineages have become major responsible of healthcare- and community-associated infections in human population. Bovine MRSA are sporadically detected in the dairy herd, but its presence enhances the risk of zoonosis. Some lineages are able to lose the specific host tropism, being easily transmitted from animals to humans and vice-versa. The present study aims at clarifying the epidemiology of MRSA intramammary infections in a closed dairy herd, which was running a mastitis control program since years. Quarter milk samples were collected from all lactating cows once a week for 9 weeks and bacteriologically tested. At the end of the follow-up period, also a self-taken nasal swab of the milker was analysed. Three cows (12.5%) were MRSA positive, a fourth showed a transient infection and MRSA was isolated also from the milker’s nose. Somatic cell counts of infected quarters fluctuated from 1000 to 1,800,000 cells/mL. The isolates were genotyped using DNA microarrays and identified as the epidemic UK-EMRSA-15 grouping in CC22. All strains carried the genes for β-lactam and macrolide resistance. The milker isolate differed from cow isolates mainly for the absence of the untruncated β-haemolysin and the presence of the immune evasion cluster. The milker had been volunteering in a nursing home since months, thus playing the role of MRSA vector into the herd. Our results showed the adaptive capacity of such MRSA to the bovine host. Therefore, we suggest that CC22-MRSA should be regarded as a potential cause of reverse zoonosis in dairy cattle herds.

Insights Into the Bovine Milk Microbiota in Dairy Farms With Different Incidence Rates of Subclinical Mastitis.

Bovine mastitis continues to be a complex disease associated with significant economic loss in dairy industries worldwide. The incidence rate of subclinical mastitis (IRSCM) can show substantial variation among different farms; however, the milk microbiota, which have a direct influence on bovine mammary gland health, have never been associated with the IRSCM. Here, we aimed to use high-throughput DNA sequencing to describe the milk microbiota from two dairy farms with different IRSCMs and to identify the predominant mastitis pathogens along with commensal or potential beneficial bacteria. Our study showed that Klebsiella, Escherichia–Shigella, and Streptococcus were the mastitis-causing pathogens in farm A (with a lower IRSCM), while Streptococcus and Corynebacterium were the mastitis-causing pathogens in farm B (with a higher IRSCM). The relative abundance of all pathogens in farm B (22.12%) was higher than that in farm A (9.82%). However, the genus Bacillus was more prevalent in farm A. These results may be helpful for explaining the lower IRSCM in farm A. Additionally, the gut-associated genera Prevotella, Ruminococcus, Bacteroides, Rikenella, and Alistipes were prevalent in all milk samples, suggesting gut bacteria can be one of the predominant microbial contamination in milk. Moreover, Listeria monocytogenes (a foodborne pathogen) was found to be prevalent in farm A, even though it had a lower IRSCM. Overall, our study showed complex diversity between the milk microbiota in dairy farms with different IRSCMs. This suggests that variation in IRSCMs may not only be determined by the heterogeneity and prevalence of mastitis-causing pathogens but also be associated with potential beneficial bacteria. In the future, milk microbiota should be considered in bovine mammary gland health management. This would be helpful for both the establishment of a targeted mastitis control system and the control of the safety and quality of dairy products.

A Critical Appraisal of Probiotics for Mastitis Control.

The urge to reduce antimicrobials use in dairy farming has prompted a search for alternative solutions. As infections of the mammary gland is a major reason for antibiotic administration to dairy ruminants, mammary probiotics have recently been presented as a possible alternative for the treatment of mastitis. To assess the validity of this proposal, we performed a general appraisal of the knowledge related to probiotics for mammary health by examining their potential modes of action and assessing the compatibility of these mechanisms with the immunobiology of mammary gland infections. Then we analyzed the literature published on the subject, taking into account the preliminary in vitro experiments and the in vivo trials. Preliminary experiments aimed essentially at exploring in vitro the capacity of putative probiotics, mainly lactic acid bacteria (LABs), to interfere with mastitis-associated bacteria or to interact with mammary epithelial cells. A few studies used LABs selected on the basis of bacteriocin production or the capacity to adhere to epithelial cells to perform in vivo experiments. Intramammary infusion of LABs showed that LABs are pro-inflammatory for the mammary gland, inducing an intense influx of neutrophils into milk during lactation and at drying-off. Yet, their capacity to cure mastitis remains to be established. A few preliminary studies tackle the possibility of using probiotics to interfere with the teat apex microbiota or to prevent the colonization of the teat canal by pathogenic bacteria. From the analysis of the published literature, it appears that currently there is no sound scientific foundation for the use of probiotics to prevent or treat mastitis. We conclude that the prospects for oral probiotics are not promising for ruminants, those for intramammary probiotics should be considered with caution, but that teat apex probiotics deserve further research.

Control of bovine mastitis in the 21st century: Immunize or tolerize?

Control of bovine mastitis in the 21st century: Immunize or tolerize?

Guide to udder health for dairy goats

An udder health guide developed for dairy goats provides guidance to producers, veterinarians, and dairy support personnel in how to control mastitis and maintain milk quality. It is divided into 8 sections that cover normal anatomy and physiology, the causes of mastitis and how to detect it, best practices for milking management, maintenance of milking equipment, and troubleshooting poor milk quality. Other sections cover treatment and control of mastitis, monitoring udder health, and health management of the dairy doe. More research is needed in some areas, although there is sufficient information available to provide a high quality udder health program to this dairy sector.

Novel lytic bacteriophages of Klebsiella oxytoca ABG-IAUF-1 as the potential agents for mastitis phage therapy.

Mastitis is an inflammation of the mammary gland that occurs when pathogenic microorganisms enter the udder. Even though tremendous advancements in veterinary diagnosis and therapeutics, mastitis is still the most frequent and costly disease of dairy herds overall the world. The purpose of this research was to isolate and identify the lytic phages as a potential method for biological control of bovine mastitis. In this study Klebsiella oxytoca was isolated from contaminated milk samples of Isfahan dairy herds, Isfahan, Iran and characterized as K. oxytoca ABG-IAUF-1 and its 16s-rRNA sequence was deposited in GenBank under the accession numbers of MF175803.1. Then, the four novel specific lytic bacteriophages of K. oxytoca ABG-IAUF-1 from Isfahan public wastewater were isolated and identified. The results of transmission electron microscopy indicated that theses isolated phages were related to Myoviridae and Podoviridae families of bacteriophages. Also the analysis of the growth curve of K. oxytoca ABG-IAUF-1 before and after treatment with lytic phage showed the 97% success rate of the phages in preventing of bacterial growth. This is the first report indicating the use of bacteriophages as the potential agents for eliminating the pathogenic bacteria responsible for bovine mastitis in Iran. The applications of these lytic phages could be an asset for biocontrolling of pathogenic agents in medical and veterinary biotechnology.

Antimicrobial Activity of Essential Oils of Lamiaceae Aromatic Spices Towards Sheep mastitis-Causing Staphylococcus aureus and Staphylococcus epidermidis

Mastitis in ewes is responsible for massive economic losses. Antibiotics are routinely used for mastitis control but its excessive use leads to development of antibiotic resistance with deleterious outcomes both for animal and public health. Essential oils (EOs) show antibacterial proprieties and no resistance has been reported after prolonged exposure; however their efficacy depends on their chemical composition. In this study EOs chemical composition from four autochthonous aromatic herbs, from Alentejo region, southern Portugal, Calamintha nepeta subsp. nepeta, Lavandula stoechas subsp. luisieri, Rosmarinus officinalis and Thymus mastichina was accessed. EOs of R. officinalis showed predominance in monoterpene hydrocarbons (63 %) whereas EOs of T. mastichina, L. luisieri and C. nepeta were rich in oxygenated monoterpenes (71-95%). The antimicrobial activity of selected EOs was investigated towards Staphylococcus aureus (n= 24) and Staphylococcus epidermidis isolates (n= 24) from ovine mastitic milk origin. Results of disk diffusion assay revealed that C. nepeta, L. luisieri and T. mastichina EOs are highly active against both S. aureus and S. epidermidis strains, whereas R. officinalis EO is highly active against S. aureus strains but inactive against several S. epidermidis isolates. EOs concentration causing bacterial growth inhibition ranged from 500 to 4,000 μg mL−1 in liquid microassays.

Milk cellularity and intramammary infections in primiparous and multiparous Lacaune ewes during early lactation

Despite the vast literature on postpartum mastitis in cattle, there is a demand for and lack of studies on the cellularity dynamics and cellular populations in milk and the occurrence of mastitis in ewes during the postpartum period. Thus, the aim of the present study was to evaluate the dynamics of cellularity in milk/colostrum and of mastitis in primiparous and multiparous Lacaune ewes during early lactation. For this purpose, 492 milk/colostrum samples were collected from the udder halves of 20 primiparous ewes and 21 multiparous ewes at the following six time points: day of parturition (T1) and one day (T2), three days (T3), seven days (T4), 15 days (T5), and 30 days (T6) after parturition. The milk and colostrum samples were subjected to microbiological examination, microscopic and automatic somatic cell counts (SCCs), differential somatic cell counts, and the California Mastitis test (CMT). The multiparous ewes had a higher prevalence of intramammary infections than the primiparous ewes during the postpartum period. Non-aureus staphylococci bacteria were the main mastitis etiological agents isolated in the present study. Furthermore, one of the most important findings of our study was that 35% of the udder halves of the primiparous ewes were infected at parturition, suggesting potential concerns for mastitis control programs. Finally, the SCC did not appear to be a good indicator of inflammation during early lactation because this measure was influenced by the parity and the sampling period. Moreover, the predictive values of the CMT and neutrophil counts were slightly better than those of the SCC during the immediate postpartum period.

Antibiotic susceptibility of Staphylococcus aureus isolated from subclinical bovine mastitis cases and in vitro efficacy of bacteriophage

Staphylococcus aureus is an opportunistic pathogen that may cause severe infections in livestock, and represents the major cause of mastitis in dairy cows. Currently, instead of using antibiotics, new strategies are sought to reduce this clinical health problem. The aim of this study was to determine the efficacy of phage therapy to kill S. aureus strains obtained from farms located at the State of Guanajuato, México. Thirty-six S. aureus strains from cow milk with subclinical mastitis were isolated and identified, and the susceptibility to antibiotics and four phages also isolated in this work was tested. It was found that more of 90% of S. aureus isolates were not susceptible to six or more antibiotics, and 100% were resistant to penicillin, dicloxacillin, cefotaxime, ampicillin and cephalothin, and 81 and 77%, to tetracycline and cefuroxime, respectively. Fortunately, 100% of S. aureus isolates were susceptible to phages used in this work, which was detected as clear zones using specific phage. It was shown for the first time, that phages used in this study are active against pathogenic S. aureus and might be incorporated into the therapy as an important tool for the control of staphylococcal bovine mastitis, specially to antibiotic-resistant S. aureus strains isolated in farm located at the state of Guanajuato, México; and its use might be extended to other regions inside or outside the country.

Milk yield losses and cost of clinical mastitis in Friesian × Bunaji crossbred dairy cows in Zaria, Nigeria

Bovine mastitis is regarded as the most costly disease of dairy cows. Estimating its economic impact therefore gives farmers and veterinarians an insight into the costs of the disease at herd level and helps them make appropriate decisions regarding its control. The aim of this study was to determine the costs of clinical mastitis in Friesian × Bunaji crossbred dairy cows. Passive data collected between 2000 and 2015 was retrieved from the Dairy Research Programme of the National Animal Production Research Institute, Shika-Zaria, Nigeria and this was used to determine the input parameters for a simulation model. The parameters included the lactation and seasonal prevalence of clinical mastitis, average daily milk yield of cows, average illness period and the proportion of cows in each parity. Stochastic (Monte Carlo) simulation modelling of milk yield losses due to clinical mastitis was done using Microsoft® Excel with @Risk 7 add-in. The cost of a case of clinical mastitis at a base risk incidence of 35.2% was ₦5,005.85 ($15.87). The costs increased by 7.5% in a herd with 10% higher milk yield, while revenue generated was higher by 10.2%. The cost was 1.64% higher in a herd with fifty per cent of it cows in first parity than a herd with fifty per cent of its cows in third parity. 1.01% higher net revenue was generated from herds with fifty per cent of it cows in third parity than the herd with fifty per cent of its cows in first parity. Improving milk production potential of cows resulted in more cases of clinical mastitis, although the increase in revenue overshadows the added costs of clinical mastitis, successful control of mastitis will also significantly reduce production costs and improve the farm revenue.Keywords: Clinical mastitis, Cost, Cows, Friesian x Bunaji, Losses, Milk yield

MOLECULAR CHARACTERIZATION OF TOXIGENIC AND ANTIBIOTIC RESISTANT OF STAPHYLOCOCCUS AUREUS OF RECURRENT BOVINE MASTITIS

To enhance the diagnosis of Staphylococcus aureus mastitis and its prospective antibiotic resistance in dairy cattle, a multiplex polymerase chain reaction (PCR) assay was developed for concurrent species identifycation, detection antibiotic resistant phenotypically and genotypically to penicillin (blaZ gene), gentamycin (aac(6') aph (2'')genes), and tetracycline (tetK, gene) and recognize the toxogenicpatterns of S. aureus in cow’s milk with recurrent clinical mastitis. Bacterial culturing was carried out on 179 bovine recurrent clinical mastitic milk samples resulted in 84 (46.9%) coagulase positive staph isolates, while 69 (38.5%) confirmed by molecular identification by PCR as S. aureus. Also some virulence factors as enterotoxin A and B (Sea and Seb) genes were determined in 7(10.1%) and 1 (1.4%) respectively in confirmed isolates. As well as determined drugs resistance and their genes. The results of antimicrobial susceptibility tests showed 100%. 43.5% and 58% resistance for penicillin, gentamycin and tetracycline respectively. While genotypically were 100%, 40.6% and 53.6% for (blaZ, aac (6') aph (2'') and tetK, respectively. This study reports the presence of multidrug resistant S. aureusin recurrent clinical mastitis with highly virulent toxic genes that could be a major obstacle in the treatment and control of mastitis in dairy farms causing highly economic impacts and recommended that the polymerase chain reaction (PCR)-based assays to detect pathogens associated with mastitis and that it has several advantages, including rapid results and high sensitivity.

Addition of Curcumin in Dairy Sheep Diet in the Control of Subclinical Mastitis

Background: Curcumin, a polyphenol derived from rhizome of Curcuma longa, has been successfully used in animals and humans due to its antibacterial and anti-inflammatory properties. Recently, a study demonstrated that curcumin ointment reduced pain, mammary tension and erythema in humans with mastitis 72 h after the treatment. Mastitis in sheep is an important problem due to restrictions associated to the use of antibiotics, affecting milk production and becoming a public health issue. Thus, the aim of this study was to verify whether the addition of curcumin in the diet of six female sheep with subclinical mastitis could have curative efficacy and benefits to animal health.Cases: Six Lacaune sheep with subclinical mastitis that persisted for more than thirty days after the parturition were used. The animals received feed containing the curcumin (60 mg/animal/day) during 10 days. On days 0 and 10 of the experiment, total blood was collected to perform the hemogram and serum biochemistry (triglycerides, cholesterol, glucose, total protein (TP), albumin, globulin, aspartate aminotransferase (AST) and urea), as well as individual milk samples for centesimal composition, somatic cell count (SCC) and total bacterial count (TBC). Total leukocytes and erythrocytes, as well as hemoglobin content, were obtained using the hematological counter CELM-CC-550. Blood smears were stained by theRomanowsky method and used for leukocytes differentiation. After ten days of treatment, five sheep were negative in the California Mastitis Test (CMT). Total erythrocytes increased, while total leukocytes decreased after the treatment. Seric levels of AST, triglycerides, cholesterol and globulins decreased, while seric levels of albumin and urea increased after tendays of treatment. No differences were observed regarding milk production and composition, as well as for SCC and TBC on days 0 and 10 post treatment.Discussion: The use curcumin to prevent or to delay the occurrence of subclinical mastitis in ewes was first tested. In an experiment of lipopolysaccharide-induced mastitis in rats, researchers identified receptors type Toll 4 which are related with the induction of the synthesis of pro-inflammatory cytokines, as tumor necrosis factor alpha, interleukin-6 and 1β, molecules involved in the migration of leukocytes to the site of inflammation. According to literature, curcumin was able to reduce theactivity of myeloperoxidase in the mammary gland, an enzyme used as indicator of neutrophil infiltration, demonstrating the potent anti-inflammatory effect of curcumin. This effect can be associated to the release of interleukin-8, a cytokine that promotes the migration of neutrophils, lymphocytes and eosinophils into the site of infection, i.e., the mammary gland. It is important to highlight that neutrophils, due to its capacity to release inflammatory mediators and to delay apoptosis, has the potential to maintain a permanent inflammatory process, effects that were prevented or reduced by curcumin, specially the apoptotic and cytotoxic effects. It is important to emphasize the direct effect of curcumin on bacteria present in the mammary gland, since it exerts potent bactericidal effect. In summary, the use of curcumin in sheep with subclinical mastitis exerted beneficial effects in the dose of 60 mg/sheep/day, since it showed 83.3% of curative efficacy in the test CMT. This effect of curcumin can be direct or indirect, since the curcumin provided in the diet showed anti-inflammatory properties byreducing oxidation reactions and cell damage. Overall, the addition of curcumin in sheep diet improved the hematological and biochemical variables after only ten days of treatment. Future studies should be performed to clarify and determine whether the curcumin provided in diet can be an alternative to treat clinical or subclinical mastitis.Keywords: curcumin, mammary infection, immunity, biochemistry parameters, ovine.

Mastitis on Rabbit Farms: Prevalence and Risk Factors.

Simple SummaryMastitis has been a subject of interest on rabbit farms. To better understand various aspects of this disease, we evaluated the work done during 2001–2017, on 531 farms in Spain and Portugal. We measured the cases of mastitis on the days of visit, with the examination of lactating females. We found an average of 4% of mastitic does; they were mostly chronic forms, since females with acute mastitis often die in a few hours. Several factors affect the occurrence of mastitis. For example, rabbit lines have different susceptibilities. The number of batches per maternity barn also influences the occurrence of disease; therefore, a single batch is better, or the duo system, which consists of moving females near parity to a clean and disinfected room. In the last 200 visited farms, we found that injectable antimicrobials were often used for the mastitis control, in addition to the hygiene practices (for example, culling diseased does and avoiding their kits being fostered).In this cross-sectional study, prevalence of clinical mastitis (PCM) and farm-specific risk factors were determined on 531 doe rabbit farms in Spain and Portugal, from January 2001 through March 2017. The information was obtained by carrying out 2367 visits and doing physical examinations of 144,455 lactating does, sorted in 2635 cohorts. Overall mean PCM was 4.05% (CI95% [3.87–4.22]), (minimum to maximum: 0–36.00% PCM). This study suggests that PCM was influenced by the variable number of batches (a batch was a group of does served the same day), per maternity barn (p < 0.0001). The duo system (does being moved to clean disinfected barns for parturition), was also an enabling risk factor for CM. The day of service or lactation stage also affected PCM. Lastly, there was an effect of the breeds or lines (p < 0.0001); mean PCM ranged between 1.29% and 7.09%. A subset of data obtained from 200 farms visited during January 2012–March 2017, was recorded to describe the use of antimicrobials against mastitis. Changes in host, husbandry, environment, and biosecurity practices, are highlighted to provide health and welfare benefits for breeding rabbits.

Antimicrobial-based dry cow therapy approaches for cure and prevention of intramammary infections: a protocol for a systematic review and meta-analysis.

In dairy herds, application of antimicrobials at drying-off is a common mastitis control measure. This article describes a protocol for systematic review and meta-analysis to address three crucial points regarding antimicrobial usage at drying-off: (1) comparative efficacy of antimicrobials used for preventing new and eliminating existing intramammary infections (IMI); (2) comparison of selective and blanket dry cow therapy approaches in preventing new and eliminating existing IMI; and (3) assessment of the extra prevention against new IMI that can be gained from using antimicrobial-teat sealant combinations versus antimicrobials alone. Five PICO (Population, Intervention, Comparator, Outcome) questions were formulated to cover the three objectives of the review. Medline, CAB Abstracts, Web of Science, and conference proceedings will be searched along with iterative screening of references. Articles will be eligible if: (1) published after 1966; (2) written in English or French; and (3) reporting field clinical trials and observational studies, conducted on dairy cows at drying-off, with at least one antimicrobial-treated group and one IMI-related outcome. Authors will independently assess the relevance of titles and abstracts, extract data, and assess bias and the overall quality of evidence. Results will be synthesized and analyzed using pairwise and network meta-analysis. The proposed study will significantly update previously conducted reviews.

Isolation of Escherichia coli, Klebsiella spp. and Staphylococcus spp. from Bovine Mastitic Milk in Nuwera Eliya District of Sri Lanka and their Sensitivity to Commonly Used Antibiotics

Aims: Mastitis is one of the very important and most common diseases among dairy cattle globally which leads to severe economical losses in the dairy industry. For the sustainability of the dairy sector it is critical that efficient, economically feasible treatment regime is available for clinical cases of mastitis as a part of the control program with minimum risk for residues in milk. Antimicrobials are the most common drugs of choice for controlling and preventing this devastating condition. But the frequent use of antibiotics leads to the development of resistant bacteria which could have an adverse effect on human health as well. To mitigate this destructive constraint in the industry, identifying the etiology and their susceptibilities to remedial measures are of paramount importance. Hence this study was aimed at isolating and identifying the common bacterial etiology Escherichia coli, Klebsiella spp. and Staphylococcus spp. of mastitis and evaluating the antimicrobial susceptibility of the isolates in order to develop mastitis control strategies in the area.&#x0D; Study Design: Milk samples were collected from mastitic cows in different stages including subclinical and clinical cases based on the results of California Mastitis Test&#x0D; Place and Duration of Study: Samples were collected from dairy farms in Nuwera Eliya District, Sri Lanka and Laboratory investigations were carried out in the Laboratory of Livestock Production, Faculty of Agricultural Sciences, Sabaragamuwa University of Sri Lanka, Between Aug. 2017 and Nov. 2017.&#x0D; Methodology: E.coli, Klebsiella spp. and Staphylococcus spp. were isolated from 31 milk samples and susceptibility to commonly used antibiotics (Trimethoprim, Oxytetracycline, Chloramphenicol, Cephalexin, Enrofloxacin and Ciprofloxacin) was determined by Kirby Bauer disk diffusion method.&#x0D; Results: The study revealed that the most common isolate was the Klebsiella spp. and it is 54.8% and other two organisms Staphylococcus spp. had 51.6% and Escherichia coli 41.9%. Of all isolated pathogen, 97.1% exhibited resistant to Cephalexin and it was the highest while lowest resistance was to Chloramphenicol (31.4%). Among the other antibiotics, 54.3% of total isolates showed resistance to Trimethoprim followed by 42.9% to Oxytetracycline and Enrofloxacin, 34.3% was resistant to Ciprofloxacin. Resistance to at least one antibiotic was observed for the isolated microorganisms. All the three isolated pathogens are more resistant to Cephalexin. Both E. coli and Klebsiella spp. show 100% resistance to Cephalexin while Staphylococci had 92.9% resistance. This further revealed that E. coli (10%) and Klebsiella spp. (27.3%) are showing the least resistance to Chloramphenicol, None of Staphylococcus spp. (0%) isolated show resistance to Enrofloxacin.&#x0D; Conclusion: Most common organisms isolated were Klebsiella spp. followed by Staphylococcus spp., E. coli and there is a resistance of isolated organisms to some commonly used antibiotics.

Herd-level associations between human–animal relationship, management, fecal cortisol metabolites, and udder health of organic dairy cows

Impact patterns of human-animal relationship (HAR) and herd stress level on udder health were investigated in a cross-sectional study on 30 German and Danish organic dairy herds also taking into account influencing factors regarding housing and management. Cow behavior (avoidance distance, tolerance to tactile interaction, release behavior) was assessed in tests, milkers' behavior recorded during milking, and information about contacts with animals during routine work gathered by interview. Additionally, stockpersons' attitudes were recorded via questionnaires. Fecal cortisol metabolites were measured in approximately 30 focal cows on each farm and used as a proxy to determine the level of distress within the herd. Management and housing were assessed on-farm. The following herd udder health indicators were calculated: the prevalence of mastitis quarters (≥100,000 cells/mL), and, from milk recording data over 1 yr retrospectively, the average somatic cell score and the self-cure rates during lactation per herd. Multivariable regression models with stepwise selection were calculated at herd level. The following HAR-related factors were associated with better udder health (in at least 1 of the final models): stockpersons' higher agreement on patience being important when moving the cows and on necessary contact to cows being pleasant, higher amount of positive interactions with cows during milking, more docile cows in the release behavior test, no routine change of milkers, more contact time during routine work, no active heifer habituation to milking, and performance of barn controls beyond routine work. Lower fecal cortisol metabolite levels were related to higher self-cure rates during lactation. Concerning housing, management, and herd characteristics, the following known factors were related to impaired udder health for at least 1 of the indicators: straw yards, automatic milking system, higher average lactation number, and less antibiotic udder treatments. The results confirm earlier findings that HAR is associated with udder health and should therefore be considered in future research and mastitis control programs. First indications of negative associations between herd stress level and mastitis curing capacity should be followed up in future studies.

Identification and drug susceptibility testing of Mycobacterium thermoresistibile and Mycobacterium elephantis isolated from a cow with mastitis

Objective: To understand the etiological characteristics and drug susceptibility of Mycobacterium thermoresistibile and Mycobacterium elephantis isolated from a cow with mastitis and provide evidence for the prevention and control of infectious mastitis in cows. Methods: The milk sample was collected from a cow with mastitis, which was pretreated with 4% NaOH and inoculated with L-J medium for Mycobacterium isolation. The positive cultures were initially identified by acid-fast staining and multi-loci PCR, then Mycobacterium species was identified by the multiple loci sequence analysis (MLSA) with 16S rRNA, hsp65, ITS and SodA genes. The drug sensitivity of the isolates to 27 antibiotics was tested by alamar blue assay. Results: Two anti-acid stain positive strains were isolated from the milk of a cow with mastitis, which were identified as non-tuberculosis mycobacterium by multi-loci PCR, and multi-loci nucleic acid sequence analysis indicated that one strain was Mycobacterium thermoresistibile and another one was Mycobacterium elephantis. The results of the drug susceptibility test showed that the two strains were resistant to most antibiotics, including rifampicin and isoniazid, but they were sensitive to amikacin, moxifloxacin, levofloxacin, ethambutol, streptomycin, tobramycin, ciprofloxacin and linezolid. Conclusions:Mycobacterium thermoresistibile and Mycobacterium elephantis were isolated in a cow with mastitis and the drug susceptibility spectrum of the pathogens were unique. The results of the study can be used as reference for the prevention and control the infection in cows.

Uso de medicamentos homeopáticos para el tratamiento de la mastitis bovina: Revisión

. Mastitis presents as the most important disease in milk cows, due to the damages caused by loss of productivity and milk discharge according to some treatments, such as antimicrobials. Faced with the problem of antibiotics due to poor application or bacterial resistance, an alternative for the control of mastitis is the use of homeopathy. The aim of the present study is to inform what has already been researched about the use of homeopathic medicines for the treatment of mastitis. Homeopathic therapy fits within the precepts of organic farming, being a suitable method for this purpose. The remedies used for the treatment of the disease are from the most diverse origins, plants, minerals, animals and of great representatively, of isolates or bacterial compounds, of microorganisms that are the cause of mastitis. The ease of administration of homeopathic medicines presents a great advantage, since in the most common form of use, it can be added in drinking water or mixed in the feed avoiding stress on the part of the animal. The results in mastitis due to the application of homeopathy can be visualized in the variation of the somatic cell count, reactions in the CMT (California Mastitis Test), absence of isolation of milk microorganisms and decrease in the percentage of cases of clinical and subclinical mastitis. Although the homeopathic treatment proves to be a great alternative for the control and treatment of mastitis, the results are quite variable due to the different methodologies used and the large number of different homeopathic medicines used.

Characterization of Coagulase-Negative Staphylococci and pheno-genotypic beta lactam resistance evaluation in samples from bovine Intramammary infection

ABSTRACT This study aimed to identify Coagulase-Negative Staphylococci (CoNS) species isolated from bovine mastitis, through phenotypic and PCR-RFLP (Restriction Fragment Length Polymorphism-Polimerase Chain Reaction) methods and to compare both techniques to matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) technique. Among them, the PCR-RFLP method, using a partially conserved sequence of the groEL gene, is a promising alternative, because of its reproducibility and reliability. On the other hand, the proteomic technique MALDI-TOF MS provides an accurate and much faster diagnosis and has been increasingly employed in microbiological identification. The pheno-genotypic profiles of beta-lactam resistance were also investigated, this characterization is important, considering that the use of antimicrobials is a key element for mastitis control in dairy farms. The concordance of the phenotypic, PCR-RFLP and MALDI-TOF MS assays to identify CoNS species was 77,5% (31/40). S. chromogenes was the species most frequently isolated. Antibiotic resistance rate was relatively low, registering values of 25.5% to penicillin, 9.6% to oxacillin and 6.2% to cefoxitin. Resistance to imipenem, cephalotin and amoxicillin+clavulanate was not observed. The mecA gene and its variant were detected in 7.6% and 4,1% of the isolates respectively. The blaZ gene was found in 43.2% of the strains resistant to penicillin.

Characteristics of advanced methods used for typing bacterial isolates from mastitis with particular reference to Staphylococci.

Staphylococci are very common human and animal pathogens. A variety of staphylococcal virulence determinates leads to vast range of infections. One of them is mastitis which is a common disease of the mammary glands. The incidence of this disease is widespread all over the world and depends on bacterial virulence and on prevention programs. The influence of mastitis on human health is not globally evaluated, however, in veterinary fields loses in milk production caused by bovine mastitis are a constant economic problem. One of the most important parts of the mastitis control programs is accurate diagnosis of the inflammation and characterization of the etiological factors which leads to reduction of mastitis spread. Recent reports show that staphylococci are common bacterial etiological factors of mastitis, and this paper is an overview of the diagnostic typing methods used for characterization of staphylococcal isolates. A number of different techniques available to applicate is described. Phenotypic methods to identify and to differentiate isolates or discriminate virulence factors are still in use, however, some advanced genetic methods offering higher discriminatory power are reported as more accurate. In fact, nowadays the most powerful tool on that field is next generation sequencing (NGS) of the whole genome, but its high cost and requirement of special laboratory equipment makes it hard to use for routine diagnostics. That is why standard PCR techniques-based methods, and the sequencing of particular genes, are mostly used for typing bacterial isolates. Most of these techniques are characterized by a high discriminatory power, big epidemiological concordance, and repeatable results. The presented report describes the techniques used most frequent in mastitis diagnostics related to staphylococci typing and shows their advantages and disadvantages.