Evaluation of a selective chromogenic medium for detecting vancomycin-resistant enterococci.

Rapid identification of vancomycin-resistant enterococci (VRE) can assist in choosing the appropriate treatment and preventing VRE spread. The performance of chromID™ VRE agar was evaluated using 184 clinical isolates of Enterococcus spp. and reference strains.

Performance of the Vitek 2 system software version 5.03 in the bacterial identification and antimicrobial susceptibility test: evaluation study of clinical and reference strains of Gram-positive cocci.

Introduction: The genera Enterococcus, Staphylococcus and Streptococcus are recognized as important Gram-positive human pathogens. The aim of this study was to evaluate the performance of Vitek 2 in identifying Gram-positive cocci and their antimicrobial susceptibilities.

Methods: One hundred four isolates were analyzed to determine the accuracy of the automated system for identifying the bacteria and their susceptibility to oxacillin and vancomycin.

Is prediffusion test an alternative to improve accuracy in screening hVISA strains and to detect susceptibility to glycopeptides/lipopeptides?

The characterization of heteroresistant vancomycin-intermediate Staphylococcus aureus strains (hVISA) is even more challenging, as no routine standardized laboratory methods are available. A total of 124 S. aureus isolates recovered from inpatients attended in hospitals of Santa Catarina State, Southern Brazil, were evaluated.

Evaluation of four different DNA extraction methods in coagulase-negative staphylococci clinical isolates.

Currently there are several methods to extract bacterial DNA based on different principles. However, the amount and the quality of the DNA obtained by each one of those methods is highly variable and microorganism dependent, as illustrated by coagulase-negative staphylococci (CoNS) which have a thick cell wall that is difficult to lyse. This study was designed to compare the quality and the amount of CoNS DNA, extracted by four different techniques: two in-house protocols and two commercial kits.

Inhibition of biofilm maturation by linezolid in meticillin-resistant Staphylococcus epidermidis clinical isolates: comparison with other drugs.

Biofilm resistance mechanisms are multifactorial and vary from one organism to another. The purpose of this study was to investigate the efficacy of linezolid against indwelling device-related meticillin-resistant Staphylococcus epidermidis (MRSE) biofilm, and compare this with other antimicrobials. MICs, minimum biofilm inhibitory concentrations (MBICs) and minimum biofilm eradication concentrations (MBECs) were determined by the microtitre plate method.

Rifampicin fails to eradicate mature biofilm formed by methicillin-resistant Staphylococcus aureus.

Introduction: Antimicrobial activity on biofilms depends on their molecular size, positive charges, permeability coefficient, and bactericidal activity. Vancomycin is the primary choice for methicillin-resistant Staphylococcus aureus (MRSA) infection treatment; rifampicin has interesting antibiofilm properties, but its effectivity remains poorly defined.

Methods: Rifampicin activity alone and in combination with vancomycin against biofilm-forming MRSA was investigated, using a twofold serial broth microtiter method, biofilm challenge, and bacterial count recovery.

Enhancement of antistaphylococcal activities of six antimicrobials against sasG-negative methicillin-susceptible Staphylococcus aureus: an in vitro biofilm model.

This study was designed to evaluate antimicrobial activities against methicillin-susceptible Staphylococcus aureus in both sessile and planktonic forms and to detect genes associated with this biofilm phenotype. Minimal biofilm inhibition and eradication concentrations (MBIC and MBEC, respectively) were determined by an in vitro biofilm model, and icaA, atlA, and sasG genes were detected by polymerase chain reaction. Vancomycin and tigecycline presented better biofilm inhibitory activity (MBIC range: 4-8 μg/mL) (P ≤ 0.

High biofilm production by invasive multiresistant staphylococci.

Biofilm-forming staphylococci are known for being opportunistic and invasive pathogens that cause severe disease, mostly catheter-related infections. Early detection and pathogenic strains carrying highly transferable resistance cassettes epidemiology are essential for infection spread control. Hence, this study was designed to evaluate staphylococci biofilm formation and SCCmec typing.