First Report of Vancomycin-Resistant Staphylococci Isolated from Healthy Carriers in Brazil

Abstract

Reduced susceptibility or resistance to vancomycin has been reported among clinical isolates of staphylococci in previous studies. In the present study we report on the isolation of four vancomycin-resistant staphylococcal strains from healthy carriers inside and outside the hospital environment. These carriers did not receive treatment with any antibiotic. All coagulase-negative staphylococcal strains showed variable levels of resistance to several antimicrobial agents, including oxacillin, and unstable resistance to vancomycin, with decreased vancomycin MICs (<4 mg/liter) after 10 days of passage in a nonselective medium. However, exposure of these revertants to vancomycin selected staphylococcal strains resistant to vancomycin at very high frequencies (10 ؊2 and 10 ؊3 ). The vancomycin resistance in these staphylococcal strains was not mediated by the van gene. The cell wall of the staphylococcal strains studied became thickest after culture in medium containing vancomycin, and the differences in cell wall thickness were statistically significant (P < 0.001). Thus, the thickening of the cell wall in these staphylococcal strains may be an important contributor to vancomycin resistance.

Emergence of vancomycin-intermediate Staphylococcus species in southern India

“…The first clinical isolate of VRSA was reported from the United States in 2002 (CDC, 2002). More recently, some workers have reported vancomycin-resistant staphylococcal strains from Brazil (Palazzo et al, 2005), Jordan (Bataineh, 2006) and India (Tiwari & Sen, 2006). Vancomycin intermediateresistant Staphylococcus haemolyticus has been reported previously (Schwalbe et al, 1987), and perhaps this is a critical antecedent of VISA.…”

Vancomycin use in a hospital with high prevalence of Methicillin-Resistant Staphylococcus aureus: comparison with Hospital Infection Control Practices Advisory Committe Guidelines (HICPAC)

“…In the United States clinical infections with vancomycin resistant Staphylococcus aureus (VRSA) were reported, in 2002 [23][24][25][26]. Vancomycin resistance in Staphylococci is also a concern, and Vancomycin intermediate resistant S. aureus has been described in Brazil [27][28][29].…”

CA-MRSA: Epidemiology of a Pathogen of a Great Concern

“…All samples carried the mecA gene of resistance to oxacillin and were negative for the genes www.intechopen.com vanA, vanB and vanC. The samples relating to employees of the hospital were also resistant to other classes of antimicrobials (Palazzo et al, 2005).…”