We analysed the antimicrobial susceptibility, biofilm formation and genotypic profiles of 27 isolates of Staphylococcus haemolyticus obtained from the blood of 19 patients admitted to a hospital in Rio de Janeiro, Brazil. Our analysis revealed a clinical significance of 36.8% and a multi-resistance rate of 92.6% among these isolates. All but one isolate carried the mecA gene. The staphylococcal cassette chromosome mec type I was the most prevalent mec element detected (67%). Nevertheless, the isolates showed clonal diversity based on pulsed-field gel electrophoresis analysis. The ability to form biofilms was detected in 66% of the isolates studied. Surprisingly, no icaAD genes were found among the biofilm-producing isolates.

In this paper we carried out a study about prevalence of the clinically significant coagulase negative staphylococcal (CNS) isolates found in an university hospital. Two hundred four CNS isolates from 191 patients obtained between the period of 1998 to 2002, were studied. About 27% (52/191) of the infection cases studied were confirmed as CNS-associated diseases. Blood stream infection (BSI) was the most frequent CNS associated-disease (25%; 13/52). The great majority of the BSI was verified in the Neonatal Intensive Care Unit (NICU). The analysis of the 52 patients medical history showed that 85% of the BSI was acquired in hospital. Most of the CNS nosocomial infections were associated with the use of indwelling medical devices. The incidence of methicillin-resistance among significant CNS isolates was 38%. In this study, a high percentage of exogenous contaminant was verified (60%), indicating that contamination of clinical specimens during sample collection is critical.

Methicillin-resistant Staphylococcus epidermidis (MRSE) and methicillin-resistant Staphylococcus haemolyticus (MRSHa) are important coagulase-negative staphylococci. They are often isolated from bacteremia in humans mainly due to their ability to form biofilm on the surfaces of medical devices. Papain is a complex mixture of proteolytic enzymes and peroxidases extracted from the latex of Carica papaya and it is recognized by accelerating the healing process of wounds. This study aimed to evaluate the ability of the MRSE and MRSHa isolates to produce biofilms. Besides this, the ability of papain to inhibit the formation of biofilms or to disrupt the ones already formed by those bacteria was analyzed. Thirty MRSHa and 30 MRSE were isolated from bacteremia and used in this study. It was observed that papain has ability to reduce biofilms formed by MRSE (p < 0.06) and by MRSHa (p = 0.0005). In addition, papain was able to disrupt mature biofilms made by MRSE (p = 0.014). No antibacterial activity of papain was observed for any isolates of MRSE and MRSHa tested. Papain has been demonstrated as a potential product for reducing biofilm. Uniterms:Staphylococcus epidermidis/methicillin-resistant. Staphylococcus haemolyticus/methicillinresistant. Biofilm/production. Papain/reducing biofilm.Staphylococcus epidermidis resistente à meticilina (MRSE) e Staphylococcus haemolyticus resistente à meticilina (MRSHa) são importantes estafilococos coagulase negativa. São frequentemente isolados em bacteremia humana, principalmente devido à capacidade de formar biofilmes nas superfícies de dispositivos médicos introduzidos no organismo. A papaína é mistura complexa de enzimas proteolíticas e peroxidases extraídas do látex de Carica papaya, reconhecida por acelerar os processos de cura de feridas. Este estudo teve como objetivo avaliar a capacidade dos MRSE e MRSHa em produzir biofilmes e analisar a capacidade da papaína em inibir a formação de biofilme ou desintegrar biofilmes já formados por essas bactérias. Observou-se que a papaína tem capacidade de reduzir a formação de biofilme por MRSE (p < 0,06) e MRSHa (p = 0,0005). Além disso, a papaína foi capaz de desintegrar biofilme maduro formado por MRSE (p = 0,014). Nenhuma atividade antibacteriana da papaína foi observada para qualquer das duas espécies de bactérias testadas. A papaína mostrou-se produto potencial para reduzir biofilme.Unitermos: Papaína. Staphylococcus epidermidis/resistente à meticilina. Staphylococcus haemolyticus/ resistente à meticilina. Biofilme/produção. Papaína/redução de biofilme. INTRODUCTIONCoagulase-negative staphylococci, especially Staphylococcus epidermidis followed by Staphylococcus haemolyticus, have been frequently reported as significant etiological agents that cause nosocomial infections (Keim et al., 2011, Kristóf et al., 2011Rosado, Romanelli, Camargos, 2011). The most important property of these staphylococci is their capability to form biofilm on the surfaces of foreign bodies introduced into the organism (Donlan, 2011;Sander et al., 2012). Th...