Prevalence of resistance phenotypes in Staphylococcus aureus and coagulase-negative isolates of venous ulcers of primary healthcare patients

Abstract

Introduction:In venous ulcers, the presence of Staphylococcus aureus and coagulase-negative staphylococcus resistance phenotypes can aggravate and limit the choices for treatment. Methods: Staphylococcus isolated from 69 patients (98 ulcers) between October of 2009 and October of 2010 were tested. The macrolide, lincosamide, streptogramin B (MLS B ) group resistance phenotype detection was performed using the D-test. Isolates resistant to cefoxitin and/or oxacillin (disk-diffusion) were subjected to the confirmatory test to detect minimum inhibitory concentration (MIC), using oxacillin strips (E-test®). Results: The prevalence of S. aureus was 83%, and 15% of coagulase-negative staphylococcus (CoNS). In addition were detected 28% of methicillin-resistant Staphylococcus aureus (MRSA) and 47% of methicillin-resistant coagulase-negative staphylococcus (MRCoNS). Among the S. aureus, 69.6% were resistant to erythromycin, 69.6% to clindamycin, 69.6% to gentamicin, and 100% to ciprofloxacin. Considering the MRSA, 74% were highly resistant to oxacillin, MIC ≥ 256µg/mL, and the MLS B c constitutive resistance predominated in 65.2%. Among the 20 isolates sensitive to clindamycin, 12 presented an inducible MLS B phenotype. Of the MRCoNS, 71.4%were resistant to erythromycin, ciprofloxacin and gentamicin. Considering the isolates positive for β-lactamases, the MIC breakpoint was between 0.5 and 2µg/mL. Conclusions: The results point to a high occurrence of multi-drug resistant bacteria in venous ulcers in primary healthcare patients, thus evidencing the need for preventive measures to avoid outbreaks caused by multi-drug resistant pathogens, and the importance of healthcare professionals being able to identifying colonized versus infected venous ulcers as an essential criteria to implementing systemic antibacterial therapy.

Prevalence and factors associated with wound colonization by Staphylococcus spp. and Staphylococcus aureusin hospitalized patients in inland northeastern Brazil: a cross-sectional study

“…In this study, slightly over 30% of the wounds colonized by S. aureus were colonized by MRSA, which is similar to previously reported findings [3,28,30-32]. Even though the present study found a lower rate of wound colonization by S. aureus than in studies conducted in other regions and other countries, the rate of antibiotic resistance was high, which may be attributed to prior antibiotic use by more than a third of the patients, the majority of whom were elderly with comorbidities, and use of multiple antibiotics.…”

Influence of Ag content on the antibacterial properties of SiC doped hydroxyapatite coatings

“…infected immunocompromised patients [47][48][49], venous ulcers [50,51], superinfection of some chronic dermatitis [52,53] etc. ), urinary infections [54,55], and respiratory infections (e.g.…”

Molecular epidemiology of methicillin‐resistant Staphylococcus aureus in the Brazilian primary health care system

“…This is one of the first studies conducted in Brazil that was designed to illustrate the epidemiology and dissemination of S. aureus within the primary health care system. Basic Health Units (BHUs) are the main point of entry into the health care system and account for approximately 80% of all health care provided in the country, but studies conducted in this setting and with this focus are sparse .…”