scholarly journals A Streptococcus uberis transposon mutant screen reveals a negative role for LiaR homologue in biofilm formation

2014 ◽  
Vol 118 (1) ◽  
pp. 1-10 ◽  
Author(s):  
T. Salomäki ◽  
T. Karonen ◽  
P. Siljamäki ◽  
K. Savijoki ◽  
T.A. Nyman ◽  
...  
Keyword(s):  
Biofilm Formation ◽  
Mutant Screen ◽  
Streptococcus Uberis ◽  
Negative Role

Fibronectin and laminin induce biofilm formation by Streptococcus uberis and decrease its penicillin susceptibility

2019 ◽  
Vol 136 ◽  
pp. 103652 ◽  
Author(s):  
Silvana A. Dieser ◽  
Aluminé S. Fessia ◽  
Anabella R. Zanotti ◽  
Claudia G. Raspanti ◽  
Liliana M. Odierno
Keyword(s):  
Biofilm Formation ◽  
Streptococcus Uberis

scholarly journals A Bioengineered Nisin Derivative to Control Biofilms of Streptococcus uberis .

2021 ◽  
Author(s):  
Mariana Pérez-Ibarreche ◽  
Des Field ◽  
R. Paul Ross ◽  
Colin Hill
Keyword(s):  
Confocal Microscopy ◽  
Biofilm Formation ◽  
Bovine Mastitis ◽  
Multidrug Resistant ◽  
Biofilm Inhibition ◽  
Promising Alternative ◽  
Streptococcus Uberis ◽  
Microscopy Analysis ◽  
The Impact ◽  
Confocal Microscopy Analysis

Antimicrobial peptides are evolving as novel therapeutic options against the increasing problem of multidrug-resistant microorganisms, and nisin is one such avenue. However, some bacteria possess a specific nisin resistance system (NSR) which cleaves the peptide reducing its bactericidal efficacy. NSR-based resistance was identified in strains of Streptococcus uberis , a ubiquitous pathogen that causes mastitis in dairy cattle. Previous studies have demonstrated that a nisin A derivative termed nisin PV, featuring S29P and I30V, exhibits enhanced resistance to proteolytic cleavage by NSR. Our objective was to investigate the ability of this nisin derivative to eradicate and inhibit biofilms of S. uberis DPC 5344 and S. uberis ATCC 700407 ( nsr+ ) using crystal violet (biomass), XTT (viability) assays and confocal microscopy (viability and architecture). When pre-established biofilms were assessed, over 60% of the biofilm biomass was reduced by both peptides compared to the untreated controls. However, a 42% higher reduction in viability was observed following treatment with nisin PV compared to nisin A. Accordingly, confocal microscopy analysis revealed significantly more dead cells on the biofilm upper surface and a reduced thickness following treatment with nisin PV. When biofilm inhibition was assessed, nisin PV inhibited biofilm formation and decrease viability up to 56% and 85% more than nisin A, respectively. Confocal microscopy analysis revealed a lack of biofilm for S. uberis ATCC 700407 and only dead cells for S. uberis DPC 5344. These results suggest that nisin PV is a promising alternative to effectively reduce the biofilm formation of S. uberis strains carrying NSR. IMPORTANCE. One of the four most prevalent species of bovine mastitis-causing pathogens is S. uberis. Its ability to form biofilms confers on the bacteria greater resistance to antibiotics requiring higher doses to be more effective. In a bid to limit antibiotic resistance development, the need for alternative antimicrobials is paramount. Bacteriocins such as nisin represent one such alternative that could alleviate the impact of mastitis caused by S. uberis. However, many strains of S. uberis have been shown to possess nisin resistance determinants such as the nisin resistance protein (NSR). In this study, we demonstrate the ability of nisin and a nisin derivative termed PV that is insensitive to NSR to prevent and remove biofilms of NSR-producing S. uberis strains. These findings will add new information to the antimicrobial, bacteriocins and control of S. uberis research fields specifically in relation to biofilms and nsr + mastitis-associated strains.

scholarly journals luxS Gene and Biofilm Formation in Streptococcus uberis Isolated from Bovine Mastitis Cases

2021 ◽  
Author(s):  
A.J. Greeshma ◽  
R.N. Ramani Pushpa ◽  
K. Lakshmi Kavitha ◽  
T. Srinivasa Rao
Keyword(s):  
Biofilm Formation ◽  
Bovine Mastitis ◽  
Economic Loss ◽  
Microtiter Plate ◽  
Good Choice ◽  
Luxs Gene ◽  
Biochemical Tests ◽  
Streptococcus Uberis ◽  
Biofilm Production

Background: Streptococcus uberis (S. uberis) is an environmental pathogen causing mastitis in Dairy cattle. It causes recurrent mastitis and reduction in milk production in livestock causing economic loss. The prevalence of S. uberis intramammary infections is due to ability of the organism to form biofilm in udder tissue. The present study is on in-vitro biofilm production, the correlation of luxS gene and the biofilm formation in S. uberis. Methods: A total of 91 mastitic milk samples were collected from cattle and buffaloes brought at Veterinary Hospitals and farms in Krishna, Guntur and West Godavari districts, Andhra Pradesh. The identification of the culture isolates was based on cultural and biochemical characteristics and confirmed by Polymerase Chain Reaction (PCR). The Streptococcus species cultures showing greyish, pinpointed colonies and/or aesculin hydrolysis on Edwards medium were further identified by various biochemical tests viz., catalase test, ninhydrin test, sodium hippurate hydrolysis test and type of haemolysis on 7% sheep blood agar. Confirmation of the isolates by PCR was followed by detection of biofilm formation using qualitative Congo red agar (CRA) method, quantitative microtiter plate (MTP) assay and biofilm gene (luxS) was detected using PCR.Conclusion: From this study it is suggestable that for biofilm study both phenotypic and genotypic methods should be taken together which can be influenced by various other factors also. MTP assay was a good choice for quantitative biofilm determination, which was giving a more accurate and understandable results. The results express that any of the isolates without luxS didn’t produce a strong biofilm and it is concluded that there may be other genes for regulation of biofilm production and/or luxS gene has a regulatory role for one or more genes related to biofilm formation in S. uberis.

Alpha- and β-casein components of host milk induce biofilm formation in the mastitis bacterium Streptococcus uberis

2011 ◽  
Vol 149 (3-4) ◽  
pp. 381-389 ◽  
Author(s):  
Emilia Varhimo ◽  
Pekka Varmanen ◽  
Adyary Fallarero ◽  
Malena Skogman ◽  
Satu Pyörälä ◽  
...  
Keyword(s):  
Biofilm Formation ◽  
Streptococcus Uberis

In vitro ability of mastitis causing pathogens to form biofilms

2017 ◽  
Vol 84 (2) ◽  
pp. 198-201 ◽  
Author(s):  
Sarah Schönborn ◽  
Nicole Wente ◽  
Jan-Hendrik Paduch ◽  
Volker Krömker
Keyword(s):  
Biofilm Formation ◽  
Extracellular Polymeric Substances ◽  
Coagulase Negative Staphylococci ◽  
Intramammary Infections ◽  
Microbial Biofilms ◽  
Streptococcus Uberis ◽  
Important Virulence Factor ◽  
Cure Rates ◽  
Main Factor

This Research Communication describes the study of in vitro biofilm formation of mastitis causing pathogens. Biofilms are communities of bacteria that are attached to a surface and to each other and are embedded in a self-produced matrix of extracellular polymeric substances. Biofilm formation is an important virulence factor that may result in recurrent or persistent udder infections and treatment failure through increased resistance to antibiotics and protection against host defences. In the present study 252 bacterial isolates from milk samples from bovine udder quarters with intramammary infections were examined with Congo Red agar (CRA) method and tube method (TM) for their ability to form biofilms. Both tests revealed a high number of biofilm-positive strains. Literature reports that the cure rates for Staphylococcus aureus infected udders are lower (27%) in comparison to cure rates of Streptococcus uberis (64–81%) or coagulase-negative staphylococci (CNS) mastitis (80–90%). The findings of the present study suggest that biofilm formation is not the main factor for the differences in cure rates of the various bacteria genera, because all tested pathogen groups showed a similarly high proportion of biofilm formation. Further research is needed to detect microbial biofilms on bovine udder epithelia.

Bacterial biofilm behavior in water-supply lines of dental units

1992 ◽  
Vol 50 (1) ◽  
pp. 882-883
Author(s):  
B.D. Tall ◽  
K.S. George ◽  
R. T. Gray ◽  
H.N. Williams
Keyword(s):  
Water Supply ◽  
Medical Devices ◽  
Biofilm Formation ◽  
Bacterial Biofilm

Studies of bacterial behavior in many environments have shown that most organisms attach to surfaces, forming communities of microcolonies called biofilms. In contaminated medical devices, biofilms may serve both as reservoirs and as inocula for the initiation of infections. Recently, there has been much concern about the potential of dental units to transmit infections. Because the mechanisms of biofilm formation are ill-defined, we investigated the behavior and formation of a biofilm associated with tubing leading to the water syringe of a dental unit over a period of 1 month.

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