Methicillin-resistant Staphylococcus aureus in cystic fibrosis patients: do we need to care? A cohort study

ABSTRACT CONTEXT AND OBJECTIVE: The prevalence of a variety of potentially pathogenic microorganisms in cystic fibrosis patients, such as methicillin-resistant Staphylococcus aureus (MRSA), has increased over the past decade. Given the increasing prevalence of MRSA and the few data available in the literature, better understanding of the clinical repercussions of colonization by this bacterium in cystic fibrosis patients becomes essential. This study aimed to evaluate the repercussions of chronic colonization by MRSA in cystic fibrosis patients. DESIGN AND SETTING: Retrospective cohort study from January 2004 to December 2013 in a cystic fibrosis reference center. METHODS: Each patient with cystic fibrosis was evaluated for nutritional status (body mass index, BMI, and BMI percentile), pulmonary function and tomographic abnormalities (modified Bhalla scores) at the time of chronic colonization by MRSA or methicillin-susceptible Staphylococcus aureus (MSSA) and throughout the study period. RESULTS: Twenty pairs of patients were included. There were no significant differences between the groups regarding nutritional characteristics. Spirometric data showed a trend towards greater obstruction of the airways in patients with MRSA. Patients with MRSA presented greater structural damage to their lungs, demonstrated not only by the total Bhalla score but also by its parameters individually. CONCLUSIONS: Patients colonized by MRSA presented greater functional and structural respiratory impairment at the time of chronic colonization. Disease progression was also faster in patients chronically colonized by MRSA than in those with MSSA. This was shown through comparisons that avoided possible confounding variables.

Methicillin-resistant Staphylococcus aureus in cystic fibrosis patients: do we need to care? A cohort study.

CONTEXT AND OBJECTIVE: The prevalence of a variety of potentially pathogenic microorganisms in cystic fibrosis patients, such as methicillin-resistant Staphylococcus aureus (MRSA), has increased over the past decade. Given the increasing prevalence of MRSA and the few data available in the literature, better understanding of the clinical repercussions of colonization by this bacterium in cystic fibrosis patients becomes essential. This study aimed to evaluate the repercussions of chronic colonization by MRSA in cystic fibrosis patients. DESIGN AND SETTING: Retrospective cohort study from January 2004 to December 2013 in a cystic fibrosis reference center. METHODS: Each patient with cystic fibrosis was evaluated for nutritional status (body mass index, BMI, and BMI percentile), pulmonary function and tomographic abnormalities (modified Bhalla scores) at the time of chronic colonization by MRSA or methicillin-susceptible Staphylococcus aureus (MSSA) and throughout the study period. RESULTS: Twenty pairs of patients were included. There were no significant differences between the groups regarding nutritional characteristics. Spirometric data showed a trend towards greater obstruction of the airways in patients with MRSA. Patients with MRSA presented greater structural damage to their lungs, demonstrated not only by the total Bhalla score but also by its parameters individually. CONCLUSIONS: Patients colonized by MRSA presented greater functional and structural respiratory impairment at the time of chronic colonization. Disease progression was also faster in patients chronically colonized by MRSA than in those with MSSA. This was shown through comparisons that avoided possible confounding variables.

Molecular characterization of methicillin-resistant Staphylococcus aureus isolated from blood in Rio de Janeiro displaying susceptibility profiles to non-ß-lactam antibiotics

Abstract The distinction between healthcare-associated MRSA (HA-MRSA) and community-associated MRSA (CA-MRSA) infections has become increasingly blurred. We assessed the molecular characterization and antimicrobial resistance profile for MRSA isolates from blood. Most of all (81.9%) isolates are related to known HA-MRSA and CA-MRSA epidemic lineages, such as, USA300, USA400, USA600, USA800 and USA1100. This is the first multicenter study in Rio de Janeiro.

Molecular characterization of methicillin-resistant Staphylococcus aureus isolated from blood in Rio de Janeiro displaying susceptibility profiles to non-ß-lactam antibiotics.

The distinction between healthcare-associated MRSA (HA-MRSA) and community-associated MRSA (CA-MRSA) infections has become increasingly blurred. We assessed the molecular characterization and antimicrobial resistance profile for MRSA isolates from blood. Most of all (81.9%) isolates are related to known HA-MRSA and CA-MRSA epidemic lineages, such as, USA300, USA400, USA600, USA800 and USA1100. This is the first multicenter study in Rio de Janeiro.

Panton-Valentine leukocidin (PVL) gene carriage among Staphylococcus aureus strains with SCCmec types I, III, IV, and V recovered from cystic fibrosis pediatric patients in Brazil.

The prevalence of methicillin-resistant Staphylococcus aureus (MRSA) is increasing in patients with cystic fibrosis (CF). We report a molecular characterization, antimicrobial resistance, and Panton-Valentine leukocidin (PVL) toxin gene detection of MRSA strains from 28 Brazilian pediatric CF patients (1 strain per patient). A significant proportion (50%) of MRSA SCCmec IV isolates was observed. Nearly half of MRSA strains harboring the PVL genes distributed in all SCCmec types detected. Multilocus sequence typing (MLST) analyses showed majority (57.1%) of the isolates belonged to known epidemic lineages, such as UK/EMRSA-3, Pediatric/USA 800, Southwest Pacific clone, and Brazilian/Hungarian clone. To our knowledge, this is the first Brazilian study of molecular epidemiology based on MLST and SCCmec typing and the first description of PVL genes in MRSA from CF patients.