Genetic diversity and virulence genes in Streptococcus uberis strains isolated from bovine mastitis

Mastitis is one of the most common and costly infectious diseases in dairy cattle worldwide. This is a multifactorial illness caused by different microorganisms, including virus, yeasts, algae, parasites, and several species of bacteria. Among these bacteria, Streptococcus uberis is an important environmental pathogen that is responsible for a large range of clinical and subclinical mammary infections, especially in intensively managed herds. Despite the increasing importance of this pathogen in the etiology of bovine mastitis, data on its virulence and diversity in Brazilian dairy herds are scarce. The aims of the present study were to investigate the virulence characteristics of S. uberis isolated from bovine mastitis and to assess the molecular epidemiology of the Brazilian isolates using pulsed-field gel electrophoresis (PFGE). In this work, 46 strains of S. uberis isolated from bovine mastitis from 26 Brazilian dairy herds were evaluated regarding their genetic diversity by PFGE using with the SmaI enzyme. Additionally, the presence of the virulence genes skc and pauA, which encode plasminogen activators, and the gene sua, which encodes an adhesion molecule in mammary epithelial cells, were assessed by PCR. Our results showed a high genetic diversity in the population, displaying many different patterns in the PFGE analysis. A high proportion of strains was positive for virulence genes in the sampled population (sua [100%], pauA [91%], and skc [91%]). The high frequency of skc, pauA, and sua genes among the studied strains suggests the importance of these virulence factors, possibly helping S. uberis in the colonization of the bovine mammary gland. Surveys of the genetic and molecular characteristics of this pathogen can improve our knowledge of bacterial activity and identify molecules that have roles in the establishment of the infection. This might help in the development of more effective measures to control and prevent bovine mastitis.

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Multidrug Resistance and Molecular Characterization of Streptococcus agalactiae Isolates From Dairy Cattle With Mastitis

Frontiers in Cellular and Infection Microbiology ◽

10.3389/fcimb.2021.647324 ◽

2021 ◽

Vol 11 ◽

Author(s):

Luciana Hernandez ◽

Enriqueta Bottini ◽

Jimena Cadona ◽

Claudio Cacciato ◽

Cristina Monteavaro ◽

...

Keyword(s):

Streptococcus Agalactiae ◽

Virulence Genes ◽

Antimicrobial Agents ◽

Bovine Mastitis ◽

Molecular Data ◽

Diffusion Method ◽

Economic Losses ◽

Molecular Characteristics ◽

Dairy Herds ◽

Disk Diffusion Method

Streptococcus agalactiae is a pathogen-associated to bovine mastitis, a health disorder responsible for significant economic losses in the dairy industry. Antimicrobial therapy remains the main strategy for the control of this bacterium in dairy herds and human In order to get insight on molecular characteristics of S. agalactiae strains circulating among Argentinean cattle with mastitis, we received 1500 samples from 56 dairy farms between 2016 and 2019. We recovered 56 S. agalactiae isolates and characterized them in relation to serotypes, virulence genes, and antimicrobial susceptibility. Serotypes III and II were the most prevalent ones (46% and 41%, respectively), followed by Ia (7%). In relation to the 13 virulence genes screened in this study, the genes spb1, hylB, cylE, and PI-2b were present in all the isolates, meanwhile, bca, cpsA, and rib were detected in different frequencies, 36%, 96%, and 59%, respectively. On the other hand, bac, hvgA, lmb, PI-1, PI-2a, and scpB genes could not be detected in any of the isolates. Disk diffusion method against a panel of eight antimicrobial agents showed an important number of strains resistant simultaneously to five antibiotics. We also detected several resistance-encoding genes, tet(M), tet(O), ermB, aphA3, and lnu(B) (9%, 50%, 32%, 32%, and 5%, respectively). The results here presented are the first molecular data on S. agalactiae isolates causing bovine mastitis in Argentina and provide a foundation for the development of diagnostic, prophylactic, and therapeutic methods, including the perspective of a vaccine.

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Molecular Characterization of Staphylococcus aureus Isolated from Bovine Mastitis and Close Human Contacts in South African Dairy Herds: Genetic Diversity and Inter-Species Host Transmission

Frontiers in Microbiology ◽

10.3389/fmicb.2017.00511 ◽

2017 ◽

Vol 8 ◽

Cited By ~ 34

Author(s):

Tracy Schmidt ◽

Marleen M. Kock ◽

Marthie M. Ehlers

Keyword(s):

Genetic Diversity ◽

Staphylococcus Aureus ◽

South African ◽

Molecular Characterization ◽

Bovine Mastitis ◽

Dairy Herds

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Host-pathogen interactions in bovine mammary epithelial cells and HeLa cells by Staphylococcus aureus isolated from subclinical bovine mastitis

Journal of Dairy Science ◽

10.3168/jds.2017-12700 ◽

2017 ◽

Vol 100 (8) ◽

pp. 6414-6421 ◽

Cited By ~ 7

Author(s):

Ivana G. Castilho ◽

Stéfani Thais Alves Dantas ◽

Hélio Langoni ◽

João P. Araújo ◽

Ary Fernandes ◽

...

Keyword(s):

Staphylococcus Aureus ◽

Epithelial Cells ◽

Hela Cells ◽

Mammary Epithelial Cells ◽

Bovine Mastitis ◽

Mammary Epithelial ◽

Host Pathogen Interactions ◽

Bovine Mammary Epithelial Cells ◽

Host Pathogen

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A Paradox in Bacterial Pathogenesis: Activation of the Local Macrophage Inflammasome Is Required for Virulence of Streptococcus uberis

Pathogens ◽

10.3390/pathogens9120997 ◽

2020 ◽

Vol 9 (12) ◽

pp. 997

Author(s):

Nathan Archer ◽

Sharon A. Egan ◽

Tracey J. Coffey ◽

Richard D. Emes ◽

M. Filippa Addis ◽

...

Keyword(s):

Mammary Epithelial Cells ◽

Ex Vivo ◽

Mammary Epithelial ◽

Inflammasome Activation ◽

Wild Type ◽

Independent Manner ◽

Streptococcus Uberis ◽

Correct Location ◽

Isogenic Mutants ◽

Transcriptomic Changes

Streptococcus uberis is a common cause of intramammary infection and mastitis in dairy cattle. Unlike other mammary pathogens, S. uberis evades detection by mammary epithelial cells, and the host–pathogen interactions during early colonisation are poorly understood. Intramammary challenge of dairy cows with S. uberis (strain 0140J) or isogenic mutants lacking the surface-anchored serine protease, SUB1154, demonstrated that virulence was dependent on the presence and correct location of this protein. Unlike the wild-type strain, the mutant lacking SUB1154 failed to elicit IL-1β from ex vivo CD14+ cells obtained from milk (bovine mammary macrophages, BMM), but this response was reinstated by complementation with recombinant SUB1154; the protein in isolation elicited no response. Production of IL-1β was ablated in the presence of various inhibitors, indicating dependency on internalisation and activation of NLRP3 and caspase-1, consistent with inflammasome activation. Similar transcriptomic changes were detected in ex vivo BMM in response to the wild-type or the SUB1154 deletion mutant, consistent with S. uberis priming BMM, enabling the SUB1154 protein to activate inflammasome maturation in a transcriptionally independent manner. These data can be reconciled in a novel model of pathogenesis in which, paradoxically, early colonisation is dependent on the innate response to the initial infection.

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Klebsiella pneumoniae isolated from bovine mastitis is cytopathogenic for bovine mammary epithelial cells

Journal of Dairy Science ◽

10.3168/jds.2019-17458 ◽

2020 ◽

Vol 103 (4) ◽

pp. 3493-3504

Author(s):

Jia Cheng ◽

Jv Zhang ◽

Bo Han ◽

Herman W. Barkema ◽

Eduardo R. Cobo ◽

...

Keyword(s):

Epithelial Cells ◽

Klebsiella Pneumoniae ◽

Mammary Epithelial Cells ◽

Bovine Mastitis ◽

Mammary Epithelial ◽

Bovine Mammary Epithelial Cells

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Inhibition of Staphylococcus aureus Invasion into Bovine Mammary Epithelial Cells by Contact with Live Lactobacillus casei

Applied and Environmental Microbiology ◽

10.1128/aem.03323-12 ◽

2012 ◽

Vol 79 (3) ◽

pp. 877-885 ◽

Cited By ~ 59

Author(s):

Damien S. Bouchard ◽

Lucie Rault ◽

Nadia Berkova ◽

Yves Le Loir ◽

Sergine Even

Keyword(s):

Staphylococcus Aureus ◽

Epithelial Cells ◽

Lactobacillus Casei ◽

Mammary Epithelial Cells ◽

Control Strategies ◽

Mammary Epithelial ◽

Dairy Herds ◽

Dependent Manner ◽

Content Type ◽

Bovine Mammary Epithelial Cells

ABSTRACTStaphylococcus aureusis a major pathogen that is responsible for mastitis in dairy herds.S. aureusmastitis is difficult to treat and prone to recurrence despite antibiotic treatment. The ability ofS. aureusto invade bovine mammary epithelial cells (bMEC) is evoked to explain this chronicity. One sustainable alternative to treat or prevent mastitis is the use of lactic acid bacteria (LAB) as mammary probiotics. In this study, we tested the ability ofLactobacillus caseistrains to prevent invasion of bMEC by twoS. aureusbovine strains, RF122 and Newbould305, which reproducibly induce acute and moderate mastitis, respectively.L. caseistrains affected adhesion and/or internalization ofS. aureusin a strain-dependent manner. Interestingly,L. caseiCIRM-BIA 667 reducedS. aureusNewbould305 and RF122 internalization by 60 to 80%, and this inhibition was confirmed for two otherL. caseistrains, including one isolated from bovine teat canal. The protective effect occurred without affecting bMEC morphology and viability. Once internalized, the fate ofS. aureuswas not affected byL. casei. It should be noted thatL. caseiwas internalized at a low rate but survived in bMEC cells with a better efficiency than that ofS. aureusRF122. Inhibition ofS. aureusadhesion was maintained with heat-killedL. casei, whereas contact between liveL. caseiandS. aureusor bMEC was required to preventS. aureusinternalization. This first study of the antagonism of LAB towardS. aureusin a mammary context opens avenues for the development of novel control strategies against this major pathogen.

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Immune relevant gene expression of mammary epithelial cells and their influence on leukocyte chemotaxis in response to different mastitis pathogens

Veterinární Medicína ◽

10.17221/5531-vetmed ◽

2012 ◽

Vol 51 (No. 4) ◽

pp. 125-132 ◽

Cited By ~ 23

Author(s):

O. Wellnitz ◽

P. Reith ◽

Haas SC ◽

Meyer HHD

Keyword(s):

Immune Response ◽

Epithelial Cells ◽

Mrna Expression ◽

Mammary Epithelial Cells ◽

Mammary Epithelial ◽

E Coli ◽

Amyloid A ◽

Streptococcus Uberis ◽

Leukocyte Chemotaxis ◽

Mastitis Pathogens

Different mastitis pathogens induce different courses of infection, i.e. more or less severe. Mammary epithelial cells play an important role in the initial combat against microorganisms by expression of cytokines and acute phase proteins that regulate the immune response. The objective of the present study was to investigate the involvement of the epithelial cells into the outcome of mastitis induced by different pathogens. Primary epithelial cell cultures isolated from milk were used to test the immune response by measuring the mRNA expression of immunomodulators and their influence on polymorph nuclear chemotaxis. Because the cells showed different responses to isolated bacterial endotoxins (lipopolysaccharide, lipoteichoic acid, and peptidoglycans) compared to whole bacteria, they were treated with heat inactivated (10 MOI) gram-negative Escherichia coli, a very common pathogen causing acute intra-mammary infections, with Staphylococcus aureus, a prevalent cause of chronic, and, Streptococcus uberis, an inducer of acute and chronic mastitis. E. coli induced an increased mRNA expression of interleukin (IL)-8 within a 1 h treatment. A treatment for 6 h with E. coli and S. aureus induced increased mRNA expression of IL-6, IL-8, TNF-á and serum amyloid A (SAA). After a 24 h treatment the expression of these immunomodulators was still elevated, except in the E. coli treatment the SAA expression showed no differences to control cells anymore. Interestingly, Str. uberis in the same concentration did only induce the expression of IL-8 after a 6 h treatment but had no influence on other immunomodulator mRNA expression. Cell culture supernatants of E. coli and S. aureus treated cells for 12 h increased leukocyte chemotaxis in a 96-well MultiScreen<sup>TM</sup>MIC-plate. S. aureus seemed to induce increased chemotaxis after shorter treatments than E. coli. In conclusion, mammary epithelial cells are involved in the different immune response to various mastitis pathogens, and the induction of chemotaxis of leukocytes from blood to milk during mastitis. Therefore, most likely epithelial cells play a role in the differential pattern of immunomediators stimulated by different pathogens.

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