Staphylococcus aureus (S. aureus) is a foodborne pathogen considered to be the world's third most important causative agent of foodborne illnesses [1]. Besides the production of enterotoxins, the formation of biofilm is increasingly being recognized as an important virulence factor in S. aureus [4]. The present study focused on the molecular characterization of S. aureus strains isolated from dairy products analyzing the biofilm-forming ability of the isolates. Forty strains were characterized by spa typing [2] and screened by PCR for the presence of enterotoxin encoding genes, and some genetic markers associated to the biofilm production [3]. Furthermore, the strains were tested for the biofilm production on polystyrene at 37°C [4]. A total of 19 spa types were found, the most frequent were t524 (7/40) and t2953 (5/40), which have been frequently reported also in other European countries. Majority of isolates (83%) showed similar distribution of adhesion genes (icaA, icaD, cna, fnbA and fnbB), toxin genes (hla and hlb), and staphylococcal regulators (sarA). Biofilm formation was observed in the 48% (19/40) of the isolates, of which 11% (2/19) strains formed biofilms strongly, 42% (8/19) moderately, and 47% (8/19) weakly. Interestingly, all strains carrying agr type III (5/40) were found to be biofilm producer, including the two strong biofilm producers. Furthermore, 62.5% of the isolates (25/40) were found to be potentially able to produce enterotoxins, carrying at least one gene encoding for staphylococcal enterotoxins. In conclusion, this study underlines the ability of S. aureus strains from dairy products to form biofilm. The biofilm formed by S. aureus on milk equipment surfaces can lead to significant food safety issues. The majority of strains (13/19) classified as biofilm producers, in fact, were found to be potentially able to produce enterotoxins. Currently, a regular cleaning and disinfecting is the first and most important step to get rid of raw milk residues and prevent biofilm formation by S. aureus in the dairy industry.

MOLECULAR CHARACTERIZATION AND BIOFILM FORMATION OF STAPHYLOCOCCUS AUREUS ISOLATED FROM DAIRY PRODUCTS / Colagiorgi, Angelo; Filipello, Virginia; DI CICCIO, Pierluigi Aldo; Tilola, Michela; Finazzi, Guido; Ianieri, Adriana. - In: Atti 71 Congresso Società Italiana delle Scienze Veterinarie - SISvet. - ELETTRONICO. - (2017), pp. 184-184. ((Intervento presentato al convegno 71 Congresso Società Italiana delle Scienze Veterinarie - SISvet tenutosi a Napoli nel 28-29-30 Giugno - 1 Luglio 2017.

MOLECULAR CHARACTERIZATION AND BIOFILM FORMATION OF STAPHYLOCOCCUS AUREUS ISOLATED FROM DAIRY PRODUCTS

COLAGIORGI, Angelo;DI CICCIO, Pierluigi Aldo;IANIERI, Adriana
2017-01-01

Abstract

Staphylococcus aureus (S. aureus) is a foodborne pathogen considered to be the world's third most important causative agent of foodborne illnesses [1]. Besides the production of enterotoxins, the formation of biofilm is increasingly being recognized as an important virulence factor in S. aureus [4]. The present study focused on the molecular characterization of S. aureus strains isolated from dairy products analyzing the biofilm-forming ability of the isolates. Forty strains were characterized by spa typing [2] and screened by PCR for the presence of enterotoxin encoding genes, and some genetic markers associated to the biofilm production [3]. Furthermore, the strains were tested for the biofilm production on polystyrene at 37°C [4]. A total of 19 spa types were found, the most frequent were t524 (7/40) and t2953 (5/40), which have been frequently reported also in other European countries. Majority of isolates (83%) showed similar distribution of adhesion genes (icaA, icaD, cna, fnbA and fnbB), toxin genes (hla and hlb), and staphylococcal regulators (sarA). Biofilm formation was observed in the 48% (19/40) of the isolates, of which 11% (2/19) strains formed biofilms strongly, 42% (8/19) moderately, and 47% (8/19) weakly. Interestingly, all strains carrying agr type III (5/40) were found to be biofilm producer, including the two strong biofilm producers. Furthermore, 62.5% of the isolates (25/40) were found to be potentially able to produce enterotoxins, carrying at least one gene encoding for staphylococcal enterotoxins. In conclusion, this study underlines the ability of S. aureus strains from dairy products to form biofilm. The biofilm formed by S. aureus on milk equipment surfaces can lead to significant food safety issues. The majority of strains (13/19) classified as biofilm producers, in fact, were found to be potentially able to produce enterotoxins. Currently, a regular cleaning and disinfecting is the first and most important step to get rid of raw milk residues and prevent biofilm formation by S. aureus in the dairy industry.
9788890909245
MOLECULAR CHARACTERIZATION AND BIOFILM FORMATION OF STAPHYLOCOCCUS AUREUS ISOLATED FROM DAIRY PRODUCTS / Colagiorgi, Angelo; Filipello, Virginia; DI CICCIO, Pierluigi Aldo; Tilola, Michela; Finazzi, Guido; Ianieri, Adriana. - In: Atti 71 Congresso Società Italiana delle Scienze Veterinarie - SISvet. - ELETTRONICO. - (2017), pp. 184-184. ((Intervento presentato al convegno 71 Congresso Società Italiana delle Scienze Veterinarie - SISvet tenutosi a Napoli nel 28-29-30 Giugno - 1 Luglio 2017.
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11381/2832435
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