The icaA gene in staphylococci from bovine mastitis

Abstract

Introduction: Staphylococcus aureus and coagulase-negative staphylococci (CNS) are frequently isolated from cows with mastitis. A main virulence factor of CNS is the ability to adhere and form biofilms. The intercellular gene cluster adhesion (ica) operon is one factor involved in biofilm production although ica-independent factors are also involved. Previous reports based on the results of S. epidermidis and S. aureus suggested that ica is highly conserved between species, but this detection decreases in other CNS biofilm producers. In this study we evaluated the presence of the icaA gene in strains of Staphylococcus spp. isolated from the milk of bovines with mastitis. Methodology: Thirty-seven staphylococci strains were evaluated by detecting the icaA gene. A new set of PCR primers was designed by consensus region of eight staphylococci from GenBank. Species characterization was performed using the Kloos and Schleifer scheme. Results: We identified the presence of the gene in S. aureus (n:4), S. chromogenes (n:4), and S. sciuri strains (n:2). We also, identified the presence of the gene in S. xylosus (n:5) for the first time. The icaA gene was not detected in S. capitis (n:1), S. epidermidis (n:2), S. hominis (n:2), S. saccharolyticus (n:1), S. simulans (n:4) and S. saprophyticus (n:3). The icaA gene was detected in 40.54% (15/37) of the CNS evaluated. Conclusions: Our results confirm the presence of the ica operon in various species of CNS pointing to polysaccharide intercellular adhesin (PIA) as the most important component for the formation of biofilms.

Coagulase Negative Staphylococci as an emerging cause of bovine mastitis: prevalence, antimicrobial resistance and biofilm formation

“…The same was reported by Oliveira and Cunha (2008) and Simojoki et al (2012). While, Rumi et al (2013) disagreed as S. chromogenes was the most predominant in their work. Tremblay et al (2013) entirely disagreed as they reported that S. epidermidis was the species with the lowest ability to form biofilm.…”

Detection of exopolysaccharide production and biofilm-related genes in Staphylococcus spp. isolated from a poultry processing plant

“…Several studies have reported a higher frequency of distribution of the ica genes and slime production in Staphylococcus isolates from milk (Melo et al, 2013;Rumi et al, 2013;Ciftci et al, 2009), meat, and contact surfaces in processing plants (Schlegelová et al, 2008), indicating the virulence potential of the strains evaluated.…”

“…Several studies have reported higher frequency of distribution of the ica genes in Staphylococcus isolates from foods (Melo et al, 2013;Rumi et al, 2013;Ciftci et al, 2009;Rode et al, 2007;Møretrø et al, 2003).…”

Staphylococcus aureuspersistence properties associated with bovine mastitis and alternative therapeutic modalities

“…However, the principal constituent is the polysaccharide intercellular adhesion (PIA), that is synthesized by enzymes encoded in the ica operon (icaABCD) (Cramton et al 1999). To date, the polysaccharide adhesion mechanism encoded by the ica operon is still considered as the most understood mechanism of biofilm formation in staphylococci in vitro and in vivo (Rumi et al 2013). Also, Another mechanism responsible for biofilm formation is mediated by a protein that was discovered for the first time in a S. aureus strain isolated from bovine mastitis cases, and it is known as the biofilm-associated protein (Bap) (Cucarella et al 2001).…”