Biofilm-forming ability profiling of Staphylococcus aureus and Staphylococcus epidermidis mastitis isolates

M. Oliveira, R. Bexiga, S. F. Nunes, C. Carneiro, Lina Cavaco, F. Bernardo, C. L. Vilela

Research output: Contribution to journalJournal articleResearchpeer-review

Abstract

Biofilm-forming ability has been increasingly recognized as an important virulence factor in Staphylococci, facilitating their persistence in the host, evading its defences and allowing bacterial survival at high antimicrobial concentrations. Staphylococcus aureus remains a major pathogen of chronic mastitis, but in the last years Staphylococcus epidermidis has emerged as a relevant mastitis pathogen. The present work aimed at the evaluation of the biofilm-forming ability of Staphylococci field isolates from bovine subclinical mastitis and at the development of a fluorescent in situ hybridisation (FISH) protocol that would allow the direct observation of biofilm formation in milk samples. The analysis of phenotypic expression in Congo Red Agar (CRA) and by FISH, showed that 37.5% of the S. aureus isolates produced biofilm, while by optical density measurement only 18.75% isolates revealed this phenotype. The results showed a fair agreement according to the kappa coefficient test (kappa = 0.259). Regarding S. epidermidis mastitis isolates, 37.5% revealed the ability to produce biofilm, but only four isolates were positive by all methods. This agreement was moderate (kappa = 0.467). The application of FISH to artificially contaminated milk samples allowed the direct observation of biofilm production by 37.5% isolates, showing total agreement with the CRA results. This method better mimics the in vivo conditions, especially in terms of the presence of calcium and iron, which in high concentrations, respectively, are known to inhibit or induce biofilm production. (c) 2006 Elsevier B.V. All rights reserved.
Original languageEnglish
JournalVeterinary Microbiology
Volume118
Issue number1-2
Pages (from-to)133-140
ISSN0378-1135
DOIs
Publication statusPublished - 2006
Externally publishedYes

Cite this

Oliveira, M., Bexiga, R., Nunes, S. F., Carneiro, C., Cavaco, L., Bernardo, F., & Vilela, C. L. (2006). Biofilm-forming ability profiling of Staphylococcus aureus and Staphylococcus epidermidis mastitis isolates. Veterinary Microbiology, 118(1-2), 133-140. https://doi.org/10.1016/j.vetmic.2006.07.008
Oliveira, M. ; Bexiga, R. ; Nunes, S. F. ; Carneiro, C. ; Cavaco, Lina ; Bernardo, F. ; Vilela, C. L. / Biofilm-forming ability profiling of Staphylococcus aureus and Staphylococcus epidermidis mastitis isolates. In: Veterinary Microbiology. 2006 ; Vol. 118, No. 1-2. pp. 133-140.
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abstract = "Biofilm-forming ability has been increasingly recognized as an important virulence factor in Staphylococci, facilitating their persistence in the host, evading its defences and allowing bacterial survival at high antimicrobial concentrations. Staphylococcus aureus remains a major pathogen of chronic mastitis, but in the last years Staphylococcus epidermidis has emerged as a relevant mastitis pathogen. The present work aimed at the evaluation of the biofilm-forming ability of Staphylococci field isolates from bovine subclinical mastitis and at the development of a fluorescent in situ hybridisation (FISH) protocol that would allow the direct observation of biofilm formation in milk samples. The analysis of phenotypic expression in Congo Red Agar (CRA) and by FISH, showed that 37.5{\%} of the S. aureus isolates produced biofilm, while by optical density measurement only 18.75{\%} isolates revealed this phenotype. The results showed a fair agreement according to the kappa coefficient test (kappa = 0.259). Regarding S. epidermidis mastitis isolates, 37.5{\%} revealed the ability to produce biofilm, but only four isolates were positive by all methods. This agreement was moderate (kappa = 0.467). The application of FISH to artificially contaminated milk samples allowed the direct observation of biofilm production by 37.5{\%} isolates, showing total agreement with the CRA results. This method better mimics the in vivo conditions, especially in terms of the presence of calcium and iron, which in high concentrations, respectively, are known to inhibit or induce biofilm production. (c) 2006 Elsevier B.V. All rights reserved.",
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Oliveira, M, Bexiga, R, Nunes, SF, Carneiro, C, Cavaco, L, Bernardo, F & Vilela, CL 2006, 'Biofilm-forming ability profiling of Staphylococcus aureus and Staphylococcus epidermidis mastitis isolates', Veterinary Microbiology, vol. 118, no. 1-2, pp. 133-140. https://doi.org/10.1016/j.vetmic.2006.07.008

Biofilm-forming ability profiling of Staphylococcus aureus and Staphylococcus epidermidis mastitis isolates. / Oliveira, M.; Bexiga, R.; Nunes, S. F.; Carneiro, C.; Cavaco, Lina; Bernardo, F.; Vilela, C. L.

In: Veterinary Microbiology, Vol. 118, No. 1-2, 2006, p. 133-140.

Research output: Contribution to journalJournal articleResearchpeer-review

TY - JOUR

T1 - Biofilm-forming ability profiling of Staphylococcus aureus and Staphylococcus epidermidis mastitis isolates

AU - Oliveira, M.

AU - Bexiga, R.

AU - Nunes, S. F.

AU - Carneiro, C.

AU - Cavaco, Lina

AU - Bernardo, F.

AU - Vilela, C. L.

PY - 2006

Y1 - 2006

N2 - Biofilm-forming ability has been increasingly recognized as an important virulence factor in Staphylococci, facilitating their persistence in the host, evading its defences and allowing bacterial survival at high antimicrobial concentrations. Staphylococcus aureus remains a major pathogen of chronic mastitis, but in the last years Staphylococcus epidermidis has emerged as a relevant mastitis pathogen. The present work aimed at the evaluation of the biofilm-forming ability of Staphylococci field isolates from bovine subclinical mastitis and at the development of a fluorescent in situ hybridisation (FISH) protocol that would allow the direct observation of biofilm formation in milk samples. The analysis of phenotypic expression in Congo Red Agar (CRA) and by FISH, showed that 37.5% of the S. aureus isolates produced biofilm, while by optical density measurement only 18.75% isolates revealed this phenotype. The results showed a fair agreement according to the kappa coefficient test (kappa = 0.259). Regarding S. epidermidis mastitis isolates, 37.5% revealed the ability to produce biofilm, but only four isolates were positive by all methods. This agreement was moderate (kappa = 0.467). The application of FISH to artificially contaminated milk samples allowed the direct observation of biofilm production by 37.5% isolates, showing total agreement with the CRA results. This method better mimics the in vivo conditions, especially in terms of the presence of calcium and iron, which in high concentrations, respectively, are known to inhibit or induce biofilm production. (c) 2006 Elsevier B.V. All rights reserved.

AB - Biofilm-forming ability has been increasingly recognized as an important virulence factor in Staphylococci, facilitating their persistence in the host, evading its defences and allowing bacterial survival at high antimicrobial concentrations. Staphylococcus aureus remains a major pathogen of chronic mastitis, but in the last years Staphylococcus epidermidis has emerged as a relevant mastitis pathogen. The present work aimed at the evaluation of the biofilm-forming ability of Staphylococci field isolates from bovine subclinical mastitis and at the development of a fluorescent in situ hybridisation (FISH) protocol that would allow the direct observation of biofilm formation in milk samples. The analysis of phenotypic expression in Congo Red Agar (CRA) and by FISH, showed that 37.5% of the S. aureus isolates produced biofilm, while by optical density measurement only 18.75% isolates revealed this phenotype. The results showed a fair agreement according to the kappa coefficient test (kappa = 0.259). Regarding S. epidermidis mastitis isolates, 37.5% revealed the ability to produce biofilm, but only four isolates were positive by all methods. This agreement was moderate (kappa = 0.467). The application of FISH to artificially contaminated milk samples allowed the direct observation of biofilm production by 37.5% isolates, showing total agreement with the CRA results. This method better mimics the in vivo conditions, especially in terms of the presence of calcium and iron, which in high concentrations, respectively, are known to inhibit or induce biofilm production. (c) 2006 Elsevier B.V. All rights reserved.

U2 - 10.1016/j.vetmic.2006.07.008

DO - 10.1016/j.vetmic.2006.07.008

M3 - Journal article

VL - 118

SP - 133

EP - 140

JO - Veterinary Microbiology

JF - Veterinary Microbiology

SN - 0378-1135

IS - 1-2

ER -