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Cow's milk is considered a complete food, providing high-quality protein and essential micronutrients, including vitamins and minerals. For medical reasons or as a lifestyle choice, consumers are replacing cow's milk with plant-based milk alternatives (PBMA); some perceive them as healthier alternatives to cow's milk due to their low saturated fatty acid content and no cholesterol content. However, the nutritional composition of PBMA is quite variable between different types and even within, which makes a comparison with cow's milk a complex issue. Furthermore, the consumption of PBMA has been associated with the development of some diseases in infants and children. Meanwhile, the consumption of cow's milk in human health is a controversial issue since it has been associated with a favorable effect in some diseases (such as obesity, type 2 diabetes, and Alzheimer's) and a negative effect in others (such as prostate cancer risk and Parkinson's disease); while in some diseases, there is no consensus in the cow's milk consumption effect. The aim of this review is to make a nutritional comparison of cow's milk with PBMA and to clarify the potential health issues related to their consumption. [ABSTRACT FROM AUTHOR]

Phage-encoded virulence genes of group A streptococci were detected in 10 (55.6%) of 18 isolates of group C streptococci that had caused bovine mastitis. Bovine isolates carried other genetic determinants, such as composite transposon Tn1207.3/F10394.4 (100%) and antimicrobial drug resistance genes erm(B)/erm(A) (22.2%), linB (16.6%), and tet(M)/tet(O) (66.7%), located on mobile elements. [ABSTRACT FROM AUTHOR]

The article describes the clinical findings typical of cases of malignant catarrhal fever (MCF) and mucosal disease, and compares these with clinical findings characteristic of the bluetongue outbreak in northern Europe. The clinical signs for which there was a significant difference in the proportion of cases presenting with each disease were appetite, demeanour, size for age, fecal appearance, adventitious lung sounds, corneal opacity, nasal discharge, halitosis, and interdigital ulceration.

The prevalence of lactose intolerance is one of the factors driving consumers toward plant-based milk alternatives (PBMA). This study aimed to analyze the carbohydrate profile of cows' milk (regular and lactose-free from both pasteurized and UHT milks; n = 80) and PBMA (n = 60) by HPLC. The study revealed that there was no significant difference in the energy content and total carbohydrate content between regular milk and lactose-free milk. Although milk and PBMA are entirely different food matrices, some PBMA types, as soya and coconut, may have energy contents and total carbohydrate contents comparable to those of milk. Furthermore, the variability observed in total carbohydrate content, as well as in carbohydrate profile, both between PBMA types and within samples of the same type, arises not only from variations in raw materials but also from the number of dilutions of the vegetable extract and the addition of different types and levels of carbohydrates, such as sucrose, fructose, or sorbitol, during PBMA manufacture. Although, milk presents a regular carbohydrate composition, differing solely between presentations (regular/lactose-free), the PBMA differs significantly between types and among the same type, not being for that reason regarded as a milk substitute., (© 2025, The Authors. Published by Elsevier Inc. on behalf of the American Dairy Science Association®. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).)

Some consumers are replacing cow's milk with plant-based milk alternatives (PBMAs). The present study aimed to characterize the lipid profiles of cow's milk ( n = 60) and PBMA types (soya, oat, rice, almond, coconut, and hazelnut; n = 10 per type). Significant differences were found in the fatty acid (FA) profiles of PBMAs and milk, particularly in FA diversity (15 FAs in PBMAs vs 54 FAs in milk) and the proportion of prime FA groups. The FA profile of coconut was dominated by saturated FAs (SFA), whereas monounsaturated FAs (MUFA) or polyunsaturated FAs (PUFA) were dominant in the remaining PBMA types. Cholesterol was not detected in any PBMA type. The FA profile of milk FAs was dominated by SFA; however, different individual SFA have varying health outcomes. Additionally, milk contains some FA groups with health-promoting properties, such as methyl-branched-chain FAs (BCFA) and conjugated linoleic acid (CLA), both of which are absent in PBMAs.

Antibiotics' action, once a 'magic bullet', is now hindered by widespread microbial resistance, creating a global antimicrobial resistance (AMR) crisis. A primary driver of AMR is the selective pressure from antimicrobial use. Between 2000 and 2015, antibiotic consumption increased by 65%, reaching 34.8 billion tons, 73% of which was used in animals. In the dairy cattle sector, antibiotics are crucial for treating diseases like mastitis, posing risks to humans, animals and potentially leading to environmental contamination. To address AMR, strategies like selective dry cow therapy, alternative treatments (nanoparticles, phages) and waste management innovations are emerging. However, most solutions are in development, emphasizing the urgent need for further research to tackle AMR in dairy farms.

Cryptosporidium is a protozoan parasite with worldwide distribution, infecting a wide range of hosts with some zoonotic species. Calves have been identified as one of the most common reservoirs of this parasite. However, little is known about the genetics of Cryptosporidium in calves in Portugal. This study aimed to molecularly characterize infections of Cryptosporidium in pre-weaned calves from the Lisbon and Tagus Valley (LTV) in Portugal. Fifty-two samples were collected from calves from eight dairy and two beef farms in LTV, Portugal. Cryptosporidium oocysts were detected by Modified Ziehl-Neelsen staining (MZN) and direct immunofluorescent assay (DFA). MZN and DFA revealed the presence of Cryptosporidium oocysts in 40.4% (21/52) and 67.3% (35/52) samples, respectively. Positive samples were analyzed by PCR-RFLP of the 18 s rRNA gene for species identification. DNA amplification of the 18S rRNA gene was successful for 88.6% (31/35) of samples. Cryptosporidium parvum was identified in 96.8% (30/31) of the samples, and from one sample Cryptosporidium bovis was identified. Cryptosporidium parvum positive samples were subtyped by sequencing the PCR product of a partial fragment of the 60 kDa glycoprotein (gp60) gene. Subtype analysis of the C. parvum isolates revealed that all isolates belonged to subtype family IIa. Four subtypes were recognized within this subtype family, including the hyper-transmissible IIaA15G2R1 subtype that is the most frequently reported worldwide (27/30), IIaA14G2R1 (1/30), IIaA16G2R1 (1/30) and IIaA19G2R1 (1/30). To our knowledge, this is the first report of C. bovis, and C. parvum subtypes IIaA14G2R1 and IIaA19G2R1 in cattle in LTV, Portugal. The presence of the zoonotic C. parvum subtype in this study suggests that pre-weaned calves are likely to be a significant reservoir of zoonotic C. parvum, highlighting the importance of animal-to-human infection transmission risk. Further molecular studies are required to better understand the epidemiology of cryptosporidiosis in Portugal., Competing Interests: Declaration of Competing Interest No conflict of interest to declare., (Copyright © 2023 The Authors. Published by Elsevier B.V. All rights reserved.)

This research paper aimed to evaluate the association between feeding waste milk to calves and the occurrence of antimicrobial multi-resistance by extended spectrum β-lactamase (ESBL) enzymes through determining their production by E. coli isolates from 32 dairy farms. Among β-lactamase enzymes, ESBL provide resistance to a wide variety of β-lactam antimicrobials including penicillin and 2nd, 3rd and 4th generation cephalosporins. Feeding waste milk to calves has been observed to lead to increased antimicrobial resistance in faecal isolates of calves. In each farm included in this study, faecal samples were collected from the rectum of five healthy calves in the first month of life and pooled into a single container. Five isolates from each pool were selected and confirmed to be E. coli by amplification of the 16S rRNA gene. ESBL production was confirmed phenotypically on 148 isolates from 31 farms by use of the double-disk synergy test. Genotypic confirmation of ESBL production was performed by PCR for the genes blaCTX-M-1, -2, -8, -9 and blaCMY-2. A questionnaire was also performed and a mixed logistic regression model was used to identify risk factors for the occurrence of antimicrobial resistance. A negative binomial regression model was also used, in order to assess whether there was any association between certain farm management practices and the number of ESBL-producing E. coli isolates from each farm. Phenotypic confirmation of ESBL production was obtained on 40 E. coli isolates from 15 farms (48.4%), whereas genotypic confirmation was obtained on 55 isolates from 20 farms (64.5%). The use of three or more different intramammary antimicrobials to treat mastitis within the previous year significantly impacted the number of ESBL-producing E. coli isolates; on farms that did so, there were more isolates in which ESBL-producing E. coli was present, when compared to farms that had used less formulations within the same time span.

This study aimed to assess the effect of Besnoitia besnoiti infection on the reproductive and productive performance of a dairy cattle herd. A serological screening was performed by indirect fluorescent antibody test (IFAT) on every animal aged over one year ( n = 262). Subsequently, 211 animals were clinically examined, with 96 of those being screened for detection of sclerocysts. The overall seroprevalence was 62.9% (CI95%: 56.1-69.5%). On clinical examination, 7.6% (16/211) of the animals presented chronic skin lesions, and 47.9% (46/96) had sclerocysts. Multivariate logistic regression showed that the time on herd represented a risk factor, and the odds of acquiring the infection increased 1.683× per additional year on herd, ranging from less than a year to 8 years. Seropositivity and the presence of sclerocysts revealed an association with a higher milk somatic cell count, which may have a considerable economic impact on dairy production. Regarding reproductive indicators, no negative impact could be associated with clinical besnoitiosis or positive serological results. In conclusion, our study highlights the need to thoroughly evaluate the economic impact of this emerging disease in dairy herd production to help with decision making at both herd and regional levels, particularly in endemic areas.

High-yielding dairy cows experience a negative energy balance and inflammatory status during the transition period. Fat supplementation increases diet energy density, and plasma n-3 polyunsaturated fatty acids (PUFA) have been proposed to improve immune function. This study tested the hypothesis that dietary supplementation with a rumen-protected and n-3 PUFA-enriched fat could ameliorate both the energetic deficit and immune status of postpartum high-yielding dairy cows, improving overall health and reproductive efficiency. At 11 d in milk (DIM), cows were randomly allocated to groups (1) n-3 PUFA (n = 29), supplemented with encapsulated linseed oil supplying additional up to 64 g/d (mean 25 ± 4 g/d) of α-linolenic acid (ALA), or (2) control (n = 31), supplemented with hydrogenated palm oil without ALA content. Fat supplements of the n-3 PUFA and control groups were available through an automated, off-parlor feeding system, and intake depended on the cow's feeding behavior. Plasma ALA concentrations were higher in n-3 PUFA than control cows, following a linear relation with supplement ingestion, resulting in a lower n-6/n-3 ratio in plasma. Metabolic parameters (body condition score and glucose and β-hydroxybutyric acid blood concentrations) were unaffected, but milk yield improved with increased intake of fat supplements. Plasma total adiponectin concentrations were negatively correlated with ingestion of n-3 PUFA-enriched fat supplement, following a linear relation with intake. Conception rate to first AI increased with higher intake of both fats, but a decrease of calving-to-conception interval occurred only in n-3 PUFA cows. Postpartum ovarian activity and endometrial inflammatory status at 45 DIM were unaffected. In conclusion, this study evinced a positive linear relation between rumen-protected linseed fat intake and plasma n-3 PUFA concentrations, which modulated adiponectin expression and improved reproductive parameters., (© 2022, The Authors. Published by Elsevier Inc. and Fass Inc. on behalf of the American Dairy Science Association®. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).)

Neonatal calves are commonly affected by diarrhea caused by different pathogens, but not always bacteria. Yet, antibiotics are routinely used as a treatment to an unknown extent. It was our goal to survey antibiotic use for the treatment of neonatal calf diarrhea in different countries and to identify influencing factors. A total of 873 farmers and veterinarians in Austria, Belgium, Portugal, and Scotland participated in a voluntary online survey. The data were analyzed using classification and regression tree analyses and chi 2 tests. Overall, 52.5% of the participants stated that they use antibiotics when treating neonatal calf diarrhea. Of those, 27% use them always, and 45% use highest priority critically important antibiotics. The most important factor differentiating antibiotic use practices was the country the participants were from, which could be due to regulatory differences between the countries. All antibiotic products stated were licensed for use in cattle, but several were not licensed for the treatment of diarrhea in calves. Our study shows that there is an urgent need for more scientific evidence to define best practices for the treatment of neonatal calf diarrhea. Furthermore, consensual criteria for antibiotic therapy must be defined, and targeted training for farmers and veterinarians must be provided.

Streptococcus dysgalactiae subsp. dysgalactiae (SDSD) has been considered a strict animal pathogen. Nevertheless, the recent reports of human infections suggest a niche expansion for this subspecies, which may be a consequence of the virulence gene acquisition that increases its pathogenicity. Previous studies reported the presence of virulence genes of Streptococcus pyogenes phages among bovine SDSD (collected in 2002-2003); however, the identity of these mobile genetic elements remains to be clarified. Thus, this study aimed to characterize the SDSD isolates collected in 2011-2013 and compare them with SDSD isolates collected in 2002-2003 and pyogenic streptococcus genomes available at the National Center for Biotechnology Information (NCBI) database, including human SDSD and S. dysgalactiae subsp. equisimilis (SDSE) strains to track temporal shifts on bovine SDSD genotypes. The very close genetic relationships between humans SDSD and SDSE were evident from the analysis of housekeeping genes, while bovine SDSD isolates seem more divergent. The results showed that all bovine SDSD harbor Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR)/Cas IIA system. The widespread presence of this system among bovine SDSD isolates, high conservation of repeat sequences, and the polymorphism observed in spacer can be considered indicators of the system activity. Overall, comparative analysis shows that bovine SDSD isolates carry speK , speC , speL , speM , spd1 , and sdn virulence genes of S. pyogenes prophages. Our data suggest that these genes are maintained over time and seem to be exclusively a property of bovine SDSD strains. Although the bovine SDSD genomes characterized in the present study were not sequenced, the data set, including the high homology of superantigens (SAgs) genes between bovine SDSD and S. pyogenes strains, may indicate that events of horizontal genetic transfer occurred before habitat separation. All bovine SDSD isolates were negative for genes of operon encoding streptolysin S, except for sagA gene, while the presence of this operon was detected in all SDSE and human SDSD strains. The data set of this study suggests that the separation between the subspecies " dysgalactiae " and " equisimilis " should be reconsidered. However, a study including the most comprehensive collection of strains from different environments would be required for definitive conclusions regarding the two taxa., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2021 Alves-Barroco, Caço, Roma-Rodrigues, Fernandes, Bexiga, Oliveira, Chambel, Tenreiro, Mato and Santos-Sanches.)

Adipokines emerged as regulators of metabolism and inflammation in several scenarios. This study evaluated the relationship between adipokines (adiponectin, chemerin and visfatin) and cytological (subclinical) endometritis, by comparing healthy (without), transient (recovered by 45 days postpartum (DPP)) and persistent (until 45 DPP) endometritis cows (n = 49). Cows with persistent endometritis had higher adiponectin concentrations in plasma (at 21 DPP, P < 0.05 and at 45 DPP, P < 0.01) and in uterine fluid (at 45 DPP, P < 0.001), and higher chemerin concentrations in plasma (P < 0.05) and uterine fluid (P < 0.01) at 45 DPP than healthy cows. Cows with persistent endometritis had higher gene transcription in the cellular pellet of uterine fluid and protein expression in the endometrium of these adipokines and their receptors than healthy cows. Adiponectin plasma concentrations allowed to discriminate healthy from persistent endometritis cows, in 87% (21 DPP) and 98% (45 DPP) of cases, and adiponectin and chemerin uterine fluid concentrations at 45 DPP allowed for this discrimination in 100% of cases. Cows with concentrations above the cutoff were a minimum of 3.5 (plasma 21 DPP), 20.4 (plasma 45 DPP), and 33.3 (uterine fluid 45 DPP) times more at risk of evidencing persistent endometritis at 45 DPP than cows with concentrations below the cutoff. Overall, results indicate a relationship between adipokine signalling and the inflammatory status of the postpartum uterus of dairy cows, evidencing that adipokines represent suitable biomarkers of subclinical endometritis, able to predict the risk of persistence of inflammation.

Bovine mastitis is an inflammation of the mammary gland caused by a multitude of pathogens with devastating consequences for the dairy industry. Global annual losses are estimated to be around €30 bn and are caused by significant milk losses, poor milk quality, culling of chronically infected animals, and occasional deaths. Moreover, mastitis management routinely implies the administration of antibiotics to treat and prevent the disease which poses serious risks regarding the emergence of antibiotic resistance. Conventional diagnostic methods based on somatic cell counts (SCC) and plate-culture techniques are accurate in identifying the disease, the respective infectious agents and antibiotic resistant phenotypes. However, pressure exists to develop less lengthy approaches, capable of providing on-site information concerning the infection, and in this way, guide, and hasten the most adequate treatment. Biosensors are analytical tools that convert the presence of biological compounds into an electric signal. Benefitting from high signal-to-noise ratios and fast response times, when properly tuned, they can detect the presence of specific cells and cell markers with high sensitivity. In combination with microfluidics, they provide the means for development of automated and portable diagnostic devices. Still, while biosensors are growing at a fast pace in human diagnostics, applications for the veterinary market, and specifically, for the diagnosis of mastitis remain limited. This review highlights current approaches for mastitis diagnosis and describes the latest outcomes in biosensors and lab-on-chip devices with the potential to become real alternatives to standard practices. Focus is given to those technologies that, in a near future, will enable for an on-farm diagnosis of mastitis.

This Technical Research communication describes results of a study aimed at detecting the presence of Map in milk fed to calves, and identifying possible risk factors for that presence. A questionnaire was performed on 37 dairy farms and waste milk samples were collected on 3 occasions separated by a minimum of 1 week. For farms not feeding waste milk, bulk tank milk samples were collected instead. A real time PCR for the detection of the IS900 sequence was performed for the detection of Map. A majority of farms (89·2%) fed waste milk, with only one pasteurising the milk before feeding it to calves. Results of the PCR showed that 51·5% of the farms that were feeding waste milk had a positive result for Map on that milk. None of the studied risk factors were significantly associated with the presence of Map in milk samples, possibly due to the small number of farms entering the study. However, the prevalence of positive samples for Map on PCR was 3·5 times higher for farms that bought in animals from a single origin and 1·9 times higher for farms that bought from multiple farms, when compared with closed farms. Having a calving area for multiple cows also increased the risk of a positive Map result by 1·5 when compared with single pens. The risk of having a positive Map result on waste milk was 1·6 times higher for farms feeding that milk to male calves and 1·4 for farms feeding to both male and female calves, when compared with farms not feeding waste milk. This study highlights paratuberculosis as one of the potential risks of feeding waste milk to calves, and the need for mitigation strategies to be in place to avoid unnecessary disease transmission.

Bovine mastitis is the most costly disease for dairy farmers, hence, control measures to prevent it are crucial for dairy farm sustainability. Staphylococcus aureus is considered a major mastitis pathogen because of its impact on milk quality and low cure rates. Prevention of S. aureus mastitis includes segregation of infected animals, whilst treatment of such animals should be performed for a longer time to improve cure rates. This makes identification of S. aureus infected quarters and animals of significant importance. The experiments reported in this research paper aimed to develop and validate a sensitive method for magnetic detection of S. aureus and of the Staphylococcus genus in raw milk samples. Mastitic milk samples were collected aseptically from 47 cows with subclinical mastitis, from 12 Portuguese dairy farms. Forty nine quarter milk samples were selected based on bacteriological results. All samples were submitted to PCR analysis. In parallel, these milk samples were mixed with a solution combining specific antibodies and magnetic nanoparticles, to be analysed using a lab-on-a-chip magnetoresistive cytometer, with microfluidic sample handling. The antibodies used in this work were a rabbit polyclonal IgG anti-S. aureus ScpA protein and a mouse monoclonal IgM anti-S. aureus ATCC 29740. This paper describes the methodology used for magnetic detection of bacteria, including analysis of false positive/negative results. This immunological recognition was able to detect bacterial presence above 100 cfu/ml, independently of antibody and targeted bacteria used in this work. Comparison with PCR results showed sensitivities of 57·1 and 79·3%, specificity values of 75 and 50%, and PPV values of 40 and 95·8% for magnetic identification of Staphylococci species with an anti-S. aureus antibody and an anti-Staphylococcus spp. antibody, respectively. Some constraints are described as well as the method's limitations in bacterial quantification. Sensitivities and specificities require to be improved, nevertheless, the methodology described may form the basis for a means of identifying S. aureus infected cows at the point of care.

Group B Streptococcus (GBS) is a host-generalist species, most notably causing disease in humans and cattle. However, the differential adaptation of GBS to its two main hosts, and the risk of animal to human infection remain poorly understood. Despite improvements in control measures across Europe, GBS is still one of the main causative agents of bovine mastitis in Portugal. Here, by whole-genome analysis of 150 bovine GBS isolates we discovered that a single CC61 clone is spreading throughout Portuguese herds since at least the early 1990s, having virtually replaced the previous GBS population. Mutations within an iron/manganese transporter were independently acquired by all of the CC61 isolates, underlining a key adaptive strategy to persist in the bovine host. Lateral transfer of bacteriocin production and antibiotic resistance genes also underscored the contribution of the microbial ecology and genetic pool within the bovine udder environment to the success of this clone. Compared to strains of human origin, GBS evolves twice as fast in bovines and undergoes recurrent pseudogenizations of human-adapted traits. Our work provides new insights into the potentially irreversible adaptation of GBS to the bovine environment., (© 2016 The Authors. Environmental Microbiology published by Society for Applied Microbiology and John Wiley & Sons Ltd.)

Bovine mastitis is the most costly disease for dairy farmers and the most frequent reason for the use of antibiotics in dairy cattle; thus, control measures to detect and prevent mastitis are crucial for dairy farm sustainability. The aim of this study was to develop and validate a sensitive method to magnetically detect Streptococcus agalactiae (a Group B streptococci) and Streptococcus uberis in raw milk samples. Mastitic milk samples were collected aseptically from 44 cows with subclinical mastitis, from 11 Portuguese dairy farms. Forty-six quarter milk samples were selected based on bacterial identification by conventional microbiology. All samples were submitted to PCR analysis. In parallel, these milk samples were mixed with a solution combining specific antibodies and magnetic nanoparticles, to be analyzed using a lab-on-a-chip magnetoresistive cytometer, with microfluidic sample handling. This paper describes a point of care methodology used for detection of bacteria, including analysis of false positive/negative results. This immunological recognition was able to detect bacterial presence in samples spiked above 100 cfu/mL, independently of antibody and targeted bacteria used in this work. Using PCR as a reference, this method correctly identified 73% of positive samples for streptococci species with an anti-S. agalactiae antibody, and 41% of positive samples for an anti-GB streptococci antibody.

Bovine mastitis is an economic burden for dairy farmers and preventive control measures are crucial for the sustainability of any dairy business. The identification of etiological agents is necessary in controlling the disease, reducing risk of chronic infections and targeting antimicrobial therapy. The suitability of a detection method for routine diagnosis depends on several factors, including specificity, sensitivity, cost, time in producing results, and suitability for large-scale sampling of milk. This article focuses on current methodologies for identification of mastitis pathogens and for detection of inflammation, as well as the advantages and disadvantages of different methods. Emerging technologies, such as transcriptome and proteome analyses and nano- and microfabrication of portable devices, offer promising, sensitive methods for advanced detection of mastitis pathogens and biomarkers of inflammation. The demand for alternative, fast, and reliable diagnostic procedures is rising as farms become bigger. Several examples of technological and scientific advances are summarized which have given rise to more sensitive, reliable and faster diagnostic results., (© 2015 The Author(s).)

Flow cytometers have been optimized for use in portable platforms, where cell separation, identification and counting can be achieved in a compact and modular format. This feature can be combined with magnetic detection, where magnetoresistive sensors can be integrated within microfluidic channels to detect magnetically labelled cells. This work describes a platform for in-flow detection of magnetically labelled cells with a magneto-resistive based cell cytometer. In particular, we present an example for the validation of the platform as a magnetic counter that identifies and quantifies Streptococcus agalactiae in milk.

The objectives of this study were to compare the impact of different coagulase-negative species (CNS) on udder health measured in terms of individual quarter milk somatic cell count (SCC) and duration of intramammary infection, and to get some insight into most likely routes of infection for different CNS species. This longitudinal observational study was performed on four farms that were sampled at 4-week intervals for a total of 12 visits each. Quarters infected with CNS were followed through time with milk samples being submitted for bacteriological culture and SCC determination. PCR amplification of the internal transcribed spacer region and sequencing of the sodA and rpoB genes were used for species allocation. Pulsed-field gel electrophoresis (PFGE) was performed to assess strain identity. The percentage of quarters affected per farm varied between 6 and 35%, with the most frequently isolated CNS species being Staphylococcus epidermidis, followed by Staph. simulans, Staph. chromogenes and Staph. haemolyticus. It was possible to follow 111 intramammary infections due to CNS through time. Duration of infection had a mean of 188 d and was not significantly different between CNS species. Geometric mean quarter SCC overall was 132 000 cells/ml and was also not significantly different between CNS species. Despite the possibility of a different epidemiology of infection, the impact in terms of udder health seems to be similar for different CNS species.

Streptococcus agalactiae (Group B Streptococcus, GBS), Streptococcus dysgalactiae subsp. dysgalactiae (Group C Streptococcus, GCS) and Streptococcus uberis are relevant mastitis pathogens, a highly prevalent and costly disease in dairy industry due to antibiotherapy and loss in milk production. The aims of this study were the evaluation of antimicrobial drug resistance patterns, particularly important for streptococcal mastitis control and the identification of strain molecular features. Antimicrobial resistance was assessed by disk diffusion against amoxicillin-clavulanic acid, cefazolin, cefoperazone, pirlimycin-PRL, rifaximin, streptomycin, chloramphenicol, erythromycin-ERY, gentamicin, tetracycline-TET and vancomycin. Genotypic relationships were identified using pulsed-field gel electrophoresis (PFGE), macrolide and/or tetracycline resistance gene profiling, GBS capsular typing, GBS virulence gene profiling and GBS and S. uberis multi locus sequence typing (MLST). The majority of the isolates were susceptible to all drugs except to aminoglycoside, macrolide, lincosamide and tetracycline. Close to half of the TET resistant isolates have tetO and tetK and almost all ERY-PRL resistant isolates have ermB. A high degree of intra-species polymorphism was found for GCS. The GBS belonged to ST-2, -554, -61, -23 lineages and five new molecular serotypes and human GBS insertion sequences in the cpsE gene were found. Also, GBS of serotype V with scpB and lmb seem to be related with GBS isolates of human origin (same ST-2 and similar PFGE). Overall our results suggested that different therapeutic programs may have been implemented in the different farms and that in most cases clones were herd-specific., (Copyright © 2012. Published by Elsevier B.V.)

Coagulase-negative staphylococci (CNS) are the most frequently isolated bacteria from milk samples in several studies worldwide. Despite their relative frequency, specific measures aiming at their control are not well established. One possible measure to include in a control programme is lactational antimicrobial treatment. The decision to perform such treatment, as well as other actions on farm, should be based on the likelihood of financial return. A deterministic model was used to evaluate whether performing an antimicrobial treatment during the lactation for quarters infected with CNS was financially justifiable. Input variables for the impact of CNS on udder health were based on a previous study by the same authors and on available literature on the subject. Prices included in the model were based on 2009/2010 conditions in Portugal. The average result per antimicrobial treated quarter was a net loss of €38·74. Performing a sensitivity analysis to evaluate how systematic variation of the input variables of the model would lead to outcome changes showed that variation in input variables nearly always led to a negative outcome, with the greatest variation in losses observed for variation in the length of treatment and milk withdrawal period (-€46·26 to -€28·49). The situations in which a net benefit was to be expected included the bulk tank somatic cell count decreasing to a level corresponding to a premium payment or to penalties being avoided, and the prevention of transmission of CNS in the milking parlour when the possibility of transmission was at its highest level. For most situations, lactational treatment of CNS subclinical mastitis was not financially justifiable.

A custom-designed microarray containing 220 virulence genes of Streptococcus pyogenes (group A Streptococcus [GAS]) was used to test group C Streptococcus dysgalactiae subsp. dysgalactiae (GCS) field strains causing bovine mastitis and group C or group G Streptococcus dysgalactiae subsp. equisimilis (GCS/GGS) isolates from human infections, with the latter being used for comparative purposes, for the presence of virulence genes. All bovine and all human isolates carried a fraction of the 220 genes (23% and 39%, respectively). The virulence genes encoding streptolysin S, glyceraldehyde-3-phosphate dehydrogenase, the plasminogen-binding M-like protein PAM, and the collagen-like protein SclB were detected in the majority of both bovine and human isolates (94 to 100%). Virulence factors, usually carried by human beta-hemolytic streptococcal pathogens, such as streptokinase, laminin-binding protein, and the C5a peptidase precursor, were detected in all human isolates but not in bovine isolates. Additionally, GAS bacteriophage-associated virulence genes encoding superantigens, DNase, and/or streptodornase were detected in bovine isolates (72%) but not in the human isolates. Determinants located in non-bacteriophage-related mobile elements, such as the gene encoding R28, were detected in all bovine and human isolates. Several virulence genes, including genes of bacteriophage origin, were shown to be expressed by reverse transcriptase PCR (RT-PCR). Phylogenetic analysis of superantigen gene sequences revealed a high level (>98%) of identity among genes of bovine GCS, of the horse pathogen Streptococcus equi subsp. equi, and of the human pathogen GAS. Our findings indicate that alpha-hemolytic bovine GCS, an important mastitis pathogen and considered to be a nonhuman pathogen, carries important virulence factors responsible for virulence and pathogenesis in humans.