%0 Journal Article
%T In Vitro Antibacterial and Antibiotic Resistance Modifying Effect of Bioactive Plant Extracts on Methicillin-Resistant Staphylococcus epidermidis
%A Romana Chovanov¨¢
%A M¨¢ria Mikul¨¢£¿ov¨¢
%A £¿tef¨¢nia Vaverkov¨¢
%J International Journal of Microbiology
%D 2013
%I Hindawi Publishing Corporation
%R 10.1155/2013/760969
%X The crude extracts of plants from Asteraceae and Lamiaceae family and essential oils from Salvia officinalis and Salvia sclarea were studied for their antibacterial as well as antibiotic resistance modifying activity. Using disc diffusion and broth microdilution assays we determined higher antibacterial effect of three Salvia spp. and by evaluating the leakage of 260£¿nm absorbing material we detected effect of extracts and, namely, of essential oils on the disruption of cytoplasmic membrane. The evaluation of in vitro interactions between plant extracts and oxacillin described in terms of fractional inhibitory concentration (FIC) indices revealed synergistic or additive effects of plant extracts and clearly synergistic effects of essential oil from Salvia officinalis with oxacillin in methicillin-resistant Staphylococcus epidermidis. 1. Introduction Staphylococcus epidermidis belongs to the group of coagulase negative staphylococci (CoNS). It is commensal microorganism that constitutes a major component of the normal skin and mucosal microflora of humans [1]. However, in recent years these bacteria have emerged as an opportunistic pathogen, important causative agents of bacteremia, and the leading cause of nosocomial infections particularly associated with indwelling medical devices (e.g., prosthetic joints and heart valves) and in individuals with a compromised immune system (e.g., cancer patients and neonates) [2, 3]. Staphylococcus epidermidis pathogenesis relies on the ability to adhere and form biofilms on the surfaces of the medical devices mentioned earlier [4]. Staphylococci are considered as naturally susceptible to almost all antimicrobial agents developed but at the same time have a reputation of rapidly developing resistance [5]. CoNS, especially S. epidermidis, are often multiresistant, including resistance to methicillin. Resistance to methicillin is at 75¨C90% among hospital isolates of S. epidermidis, which is even higher than the corresponding rate for S. aureus (40¨C60%) [6]. In addition to methicillin resistance, S. epidermidis strains have acquired resistance to several other antibiotics. Most antibiotic resistance genes are plasmid-encoded and are more often found in methicillin-resistant than methicillin-susceptible strains [7]. These facts together with the ubiquity of S. epidermidis as a human commensal microorganism render this bacterium an optimal carrier and reservoir for antibiotic resistance genes and for the transfer of genetic elements to pathogenic bacteria. The increasingly growing rate of antibiotic resistance of
%U http://www.hindawi.com/journals/ijmicro/2013/760969/