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Transboundary and Emerging Diseases May 2018Environmental mastitis is the most common and costly form of mastitis in modern dairy herds where contagious transmission of intramammary pathogens is controlled through... (Review)
Review
Environmental mastitis is the most common and costly form of mastitis in modern dairy herds where contagious transmission of intramammary pathogens is controlled through implementation of standard mastitis prevention programmes. Environmental mastitis can be caused by a wide range of bacterial species, and binary classification of species as contagious or environmental is misleading, particularly for Staphylococcus aureus, Streptococcus uberis and other streptococcal species, including Streptococcus agalactiae. Bovine faeces, the indoor environment and used pasture are major sources of mastitis pathogens, including Escherichia coli and S. uberis. A faeco-oral transmission cycle may perpetuate and amplify the presence of such pathogens, including Klebsiella pneumoniae and S. agalactiae. Because of societal pressure to reduce reliance on antimicrobials as tools for mastitis control, management of environmental mastitis will increasingly need to be based on prevention. This requires a reduction in environmental exposure through bedding, pasture and pre-milking management and enhancement of the host response to bacterial challenge. Efficacious vaccines are available to reduce the impact of coliform mastitis, but vaccine development for gram-positive mastitis has not progressed beyond the "promising" stage for decades. Improved diagnostic tools to identify causative agents and transmission patterns may contribute to targeted use of antimicrobials and intervention measures. The most important tool for improved uptake of known mastitis prevention measures is communication. Development of better technical or biological tools for management of environmental mastitis must be accompanied by development of appropriate incentives and communication strategies for farmers and veterinarians, who may be confronted with government-mandated antimicrobial use targets if voluntary reduction is not implemented.
Topics: Animals; Anti-Bacterial Agents; Cattle; Dairying; Escherichia coli Infections; Feces; Female; Klebsiella Infections; Mastitis, Bovine; Milk; Staphylococcal Infections; Streptococcal Infections
PubMed: 29083115
DOI: 10.1111/tbed.12704 -
Frontiers in Immunology 2021() is an important pathogen causing mastitis, which causes continuous inflammation and dysfunction of mammary glands and leads to enormous economic losses. Most...
() is an important pathogen causing mastitis, which causes continuous inflammation and dysfunction of mammary glands and leads to enormous economic losses. Most research on infection continues to be microbial metabolism-centric, and many overlook the fact that pathogens require energy from host. Mouse is a common animal model for studying bovine mastitis. In this perspective, we uncover metabolic reprogramming during host immune responses is associated with infection-driven inflammation, particularly when caused by intracellular bacteria. Taurine, a metabolic regulator, has been shown to effectively ameliorate metabolic diseases. We evaluated the role of taurine in the metabolic regulation of -induced mastitis. Metabolic profiling indicates that exposure triggers inflammation and metabolic dysfunction of mammary glands and mammary epithelial cells (the main functional cells in mammary glands). Challenge with upregulates glycolysis and oxidative phosphorylation in MECs. Pretreatment with taurine restores metabolic homeostasis, reverses metabolic dysfunction by decrease of lipid, amino acid and especially energy disturbance in the infectious context, and alleviates excessive inflammatory responses. These outcomes depend on taurine-mediated activation of the AMPK-mTOR pathway, which inhibits the over activation of inflammatory responses and alleviates cellular damage. Thus, metabolic homeostasis is essential for reducing inflammation. Metabolic modulation can be used as a prophylactic strategy against mastitis.
Topics: AMP-Activated Protein Kinases; Animals; Disease Models, Animal; Energy Metabolism; Epithelial Cells; Female; Host-Pathogen Interactions; Macrophages; Mammary Glands, Animal; Mastitis; Mice; Mice, Inbred C57BL; RAW 264.7 Cells; Signal Transduction; Streptococcal Infections; Streptococcus; TOR Serine-Threonine Kinases; Taurine
PubMed: 34177964
DOI: 10.3389/fimmu.2021.696101 -
Microbial Pathogenesis Oct 2023Autophagy is a highly conserved cellular defensive mechanism that can eliminate bacterial pathogens such as Streptococcus uberis, that causes mastitis in cows. However,...
Streptococcus uberis induced expressions of pro-inflammatory IL-6, TNF-α, and IFN-γ in bovine mammary epithelial cells associated with inhibited autophagy and autophagy flux formation.
Autophagy is a highly conserved cellular defensive mechanism that can eliminate bacterial pathogens such as Streptococcus uberis, that causes mastitis in cows. However, S. uberis induced autophagy is still unclear. In this study, we tested if certain inflammatory cytokines such as IL-6, TNF-α, and IFN-γ, critical in mastitis due to S. uberis infection, regulate autophagy activation in bovine mammary epithelial cells (bMECs). Using Western blot and laser scanning confocal microscope in bMECs challenged by S. uberis, showed that the expression of IL-6, TNF-α, IFN-γ oscillated with the expressions of autophagic Atg5, ULK1, PTEN, P62, and LC3ӀӀ/LC3Ӏ. S. uberis infection induced autophagosomes and LC3 puncta in bMECs with upregulation of Atg5, ULK1, PTEN, LC3ӀӀ/LC3Ӏ, and downregulation of P62. The levels of IL-6, TNF-α, and IFN-γ increased during autophagy flux formation to decrease during autophagy induction. Autophagy inhibition increased the expression of IL-6, TNF-α, and IFN-γ and increased S. uberis burden. This study indicates autophagy is induced during S. uberis infection and IL-6, TNF-α, and IFN-γ contribute to autophagy and autophagy flux formation.
Topics: Female; Cattle; Animals; Humans; Tumor Necrosis Factor-alpha; Streptococcal Infections; Interleukin-6; Mammary Glands, Animal; Interferon-gamma; Epithelial Cells; Autophagy; Mastitis, Bovine
PubMed: 37499842
DOI: 10.1016/j.micpath.2023.106270 -
Journal of Dairy Science Feb 2016The objectives of study were to determine the transmission parameters (β), durations of infection, and basic reproductive numbers (R0) of both Streptococcus agalactiae... (Comparative Study)
Comparative Study
The objectives of study were to determine the transmission parameters (β), durations of infection, and basic reproductive numbers (R0) of both Streptococcus agalactiae and Streptococcus uberis as pathogens causing mastitis outbreaks in dairy herds. A 10-mo longitudinal study was performed using 2 smallholder dairy herds with mastitis outbreaks caused by Strep. agalactiae and Strep. uberis, respectively. Both herds had poor mastitis control management and did not change their milking management during the entire study period. Quarter milk samples were collected at monthly intervals from all lactating animals in each herd for bacteriological identification. The durations of infection for Strep. uberis intramammary infection (IMI) and Strep. agalactiae IMI were examined using Kaplan-Meier survival curves, and the Kaplan-Meier survival functions for Strep. uberis IMI and Strep. agalactiae IMI were compared using log rank survival-test. The spread of Strep. uberis and Strep. agalactiae through the population was determined by transmission parameter, β, the probability per unit of time that one infectious quarter will infect another quarter, assuming that all other quarters are susceptible. For the Strep. uberis outbreak herd (31 cows), 56 new infections and 28 quarters with spontaneous cure were observed. For the Strep. agalactiae outbreak herd (19 cows), 26 new infections and 9 quarters with spontaneous cure were observed. The duration of infection for Strep. agalactiae (mean=270.84 d) was significantly longer than the duration of infection for Strep. uberis (mean=187.88 d). The transmission parameters (β) estimated (including 95% confidence interval) for Strep. uberis IMI and Strep. agalactiae IMI were 0.0155 (0.0035-0.0693) and 0.0068 (0.0008-0.0606), respectively. The R0 (including 95% confidence interval) during the study were 2.91 (0.63-13.47) and 1.86 (0.21-16.61) for Strep. uberis IMI and Strep. agalactiae IMI, respectively. In conclusion, the transmission parameter and R0 values were not different between both pathogens; however, the duration of infection for Strep. agalactiae was longer than Strep. uberis. These suggest that Strep. uberis may have a different transmission dynamic compared with Strep. agalactiae.
Topics: Animals; Cattle; Disease Outbreaks; Female; Lactation; Longitudinal Studies; Mastitis, Bovine; Milk; Streptococcal Infections; Streptococcus; Streptococcus agalactiae
PubMed: 26686709
DOI: 10.3168/jds.2015-9950 -
Frontiers in Veterinary Science 2023Streptococci are the major etiology in mastitis in dairy cattle, a cause of huge economic losses in the dairy industries. This study was aimed to determine the diversity...
INTRODUCTION
Streptococci are the major etiology in mastitis in dairy cattle, a cause of huge economic losses in the dairy industries. This study was aimed to determine the diversity of spp. isolated from clinical mastitis of cattle reared in Bangladesh.
METHODS
A total of 843 lactating cattle reared in four prominent dairy farms and one dairy community were purposively included in this study where 80 cattle were positive to clinical mastitis (CM) based on gross changes in the udder (redness, swelling, and sensitive udder) and/or milk (flakes and/or clots). Milk samples were collected from all the eighty cattle with clinical mastitis (CCM) and twenty five apparently healthy cattle (AHC). Samples were enriched in Luria Bertani broth (LB) and one hundred microliter of the enrichment culture was spread onto selective media for the isolation of spp., spp., spp., and spp., the major pathogen associated with mastitis. Isolates recovered from culture were further confirmed by species specific PCR.
RESULTS AND DISCUSSION
Out of 105 samples examined 56.2% (59/105), 17.14% (18/105), 9.52% (10/105) and 22.9% (24/105) samples were positive for , , and , respectively. This study was then directed to the determination of diversity of spp. through the sequencing of . A total of eighteen of the samples from CCM (22.5%) but none from the AHC were positive for spp. by cultural and molecular examination. Sequencing and phylogenetic analysis of identified 55.6, 33.3, 5.6 and 5.6% of the isolates as , , and , respectively. Considering the high prevalence and worldwide increasing trend of in mastitis, in-depth molecular characterization of was performed through whole genome sequencing. Five of the strain isolated in this study were subjected to WGS and on analysis two novel ST types of were identified, indicating the presence of at least two different genotypes of in the study areas. On virulence profiling, all the isolates harbored at least 35 virulence and putative virulence genes probably associated with intramammary infection (IMI) indicating all the isolated in this study are potential mastitis pathogen. Overall findings suggest that encountered in bovine mastitis is diverse and might be predominantly associated with CM in the study areas. The genome carries an array of putative virulence factors that need to be investigated genotypically and phenotypically to identify a specific trait governing the virulence and fitness of this bacterium. Moreover, the genomic information could be used for the development of new genomic tools for virulence gene profiling of .
PubMed: 37533458
DOI: 10.3389/fvets.2023.1198393 -
Antibiotics (Basel, Switzerland) Oct 2023is one of the most important causative agents of mastitis and is a common reason for the use of antimicrobials in dairy cows. In this study, we assessed the...
is one of the most important causative agents of mastitis and is a common reason for the use of antimicrobials in dairy cows. In this study, we assessed the antimicrobial susceptibility of 667 isolates originating from 216 Czech dairy farms collected between 2019 and 2023 using the broth microdilution method. We tested 140 of the isolates for the presence of antimicrobial genes using whole-genome sequencing and evaluated their relationship with phenotypic resistance. isolates showed high levels of resistance to tetracycline (59%), followed by streptomycin (38%) and clindamycin (29%). Although all of the isolates were susceptible to beta-lactams, a relatively high percentage of intermediately susceptible isolates was recorded for ampicillin (44%) and penicillin (18%). The isolates were mainly resistant to tetracycline alone (31.3%); the second most frequent occurrence of the phenotypic profile was simultaneous resistance to tetracycline, streptomycin, and clindamycin (16.6%). The occurrence of antibiotic resistance genes did not always match the phenotypic results; in total, 36.8% of isolates that possessed the gene did not show phenotypic resistance to streptomycin. To a lesser extent, silent genes were also detected in clindamycin and tetracycline. This study confirmed the high susceptibility of to penicillins used as first-line antimicrobials for mastitis treatment.
PubMed: 37887228
DOI: 10.3390/antibiotics12101527 -
Microbiology and Immunology Mar 2022Streptococcus uberis is a common cause of mastitis. The pathogenicity among different strains of S. uberis and the resultant host immune responses remain to be...
Streptococcus uberis is a common cause of mastitis. The pathogenicity among different strains of S. uberis and the resultant host immune responses remain to be elucidated. Herein, we document immune responses among three strains of S. uberis, and preliminary explore whether and how intestinal immunity plays a role in host anti-infection processes. Mice have been proved to be effective experimental animals for bovine mastitis, so utilizing a mouse intramammary infection model, we assay immune responses and gut flora changes of three S. uberis strains by histopathologic examination, RT-PCR, Western blot, and 16s ribosomal DNA sequencing. We find that the immune responses among the three sequence-type (ST) S. uberis strains may be linked to the hasA/B and lbp virulence genes, and the beta diversity of the intestine may be independent of the ST of S. uberis. Twenty phyla and 30 genera of intestinal flora were identified, with Verrucomicrobia and Akkermansia being the most prominent phylum and genus, respectively. These bacteria have strong anti-inflammatory and protective effects against S. uberis challenge. These data provide a foundation for further studies to elucidate gut flora function and exploration of therapeutic targets for mastitis.
Topics: Animals; Cattle; Female; Gastrointestinal Microbiome; Humans; Immunity; Mastitis, Bovine; Mice; Streptococcal Infections; Streptococcus
PubMed: 34842300
DOI: 10.1111/1348-0421.12955 -
Journal of Dairy Science Nov 2021Streptococcus uberis is a major causative agent of bovine mastitis worldwide, negatively affecting both milk production and animal welfare. Mammary infections result...
Streptococcus uberis is a major causative agent of bovine mastitis worldwide, negatively affecting both milk production and animal welfare. Mammary infections result from environmental reservoirs, with cattle themselves required to propagate the infection cycle. Two longitudinal studies were performed to investigate the prevalence of Streptococcus uberis within feces and to evaluate factors which may affect gastrointestinal carriage. Bacterial detection was confirmed using a PCR-based method directed against sub0888 that detected S. uberis at an analytical sensitivity of 12 cfu/g of bovine feces. The first study sampled an entire herd at 8-wk intervals, over a 10-mo period and identified that maintenance of S. uberis within the dairy cow environment was due to a high proportion of animals shedding S. uberis and not due to a low number of "super-shedding" cows within the herd. Seasonality influenced detection rates, with detection levels significantly higher for housed cattle compared with those at pasture. Multilevel logistic regression was used to identify significant factors that affected S. uberis detection; these included parity, stage of lactation, and body condition score. An additional study involved screening a smaller cohort of cows housed over a 4-wk period and identified an increased probability of detection if cows were housed in loose straw yards, compared those in straw cubicles. This study highlighted several cow and management related factors that affect both detection of S. uberis and future infection risks.
Topics: Animals; Cattle; Cattle Diseases; Feces; Female; Mastitis, Bovine; Milk; Prevalence; Streptococcal Infections; Streptococcus
PubMed: 34334197
DOI: 10.3168/jds.2021-20310 -
Journal of Dairy Science Oct 2019Bovine clinical mastitis quarter foremilk samples were collected from 15 German dairy farms for the isolation of Streptococcus uberis strains. Samples were also...
Bovine clinical mastitis quarter foremilk samples were collected from 15 German dairy farms for the isolation of Streptococcus uberis strains. Samples were also collected from the 8 spots where Streptococcus uberis was most expected in the dairy environment to investigate the transmission behavior of Streptococcus uberis within the farm. The selected environmental spots for sampling were the inner surface of the milking liner, drinking troughs (on pasture and in the barn), exit area of milking parlor, bedding material from the lying area in the barn, passageway to pasture, lying area of soil or vegetation on pasture, and the barn area in front of the milking parlor. We performed pulsed-field gel electrophoresis on 237 Streptococcus uberis isolates to identify environmental strains that matched those from mastitis milk. The same strains were detected on the passageway to the pasture, milking parlor waiting area, in one of the liners, and a drinking trough. Streptococcus uberis strains showed high variability within farms and because identical strains (in mastitis milk and environment) were found in different environmental localizations, its transmission appears to be farm specific. Thus, to establish a farm-specific mastitis control strategy, the main environmental sources of Streptococcus uberis must be analyzed for matching strains. A molecular method such as pulsed-field gel electrophoresis is an important tool that can be used to obtain the necessary information.
Topics: Animals; Cattle; Dairying; Electrophoresis, Gel, Pulsed-Field; Female; Housing, Animal; Mastitis, Bovine; Milk; Streptococcal Infections; Streptococcus
PubMed: 31421887
DOI: 10.3168/jds.2019-16669 -
Revista Argentina de Microbiologia 2017Streptococcus uberis has become one of the most important environmental pathogens associated with clinical and subclinical bovine mastitis. Biofilm confers to bacteria...
Streptococcus uberis has become one of the most important environmental pathogens associated with clinical and subclinical bovine mastitis. Biofilm confers to bacteria more resistance to physical and chemical agents as well as to different mechanisms of the innate immune system. The aim of this work was to evaluate the ability of in vitro biofilm production in 32 S. uberis isolates from bovine mastitis and identified by biochemical tests and subsequently confirmed by the amplification of the pauA gene. The isolates were cultivated in TMP broth and TMP broth with the addition of 0.5% glucose, 1% sucrose, 1% lactose or 0.5% skim milk in microtiter plates stained with crystal violet. We demonstrated that S. uberis isolated from bovine mastitis are able to produce biofilms in TMP broth and, also that biofilm formation by S. uberis can be significantly enhanced by the addition of 0.5% glucose or 1% sucrose to TMP broth. This may suggest that the carbohydrates in milk or within the ruminant gut might affect the growth mode of S. uberis. In addition, our results showed that in vitro biofilm production under different conditions of supplementation displays variation among the isolates and that each isolate shows a particular profile of biofilm production. This phenotypic heterogeneity in biofilm production exhibited by S. uberis could at least partly explain why this bacterium has the ability to adapt to different niches facilitating survival to diverse and stressful conditions.
Topics: Animals; Biofilms; Carbohydrates; Cattle; Female; Mastitis, Bovine; Milk; Streptococcal Infections; Streptococcus
PubMed: 28774481
DOI: 10.1016/j.ram.2017.04.007