Molecular Characterization of Staphylococcus aureus Isolates Obtained from Hemodialyzed Patients at the Hospital de Clínicas of Paraguay: A pilot study

Background: Patients undergoing hemodialysis are susceptible to the nasal carriage of Staphylococcus aureus , increasing the risk of developing infections that are associated with higher morbidity and mortality. The objective of this study was to describe the frequency of S. aureus carriage in hemodialysis patients and to perform molecular analysis of isolates by applying Multiple-Locus Variable Analysis. Methods: A descriptive cross sectional study with non-probabilistic sampling of consecutive cases was performed. In October 2013, 28 hemodialysis patients attending to the Nephrology Department of Hospital de Clinicas, Paraguay were included. All patients voluntarily agreed to participate. Reviews of medical history, microbiological and molecular analysis as patient interviews were made. Results: The frequency of S. aureus carriage was 50% (14/28), 92.9% of which (13/14) were methicillin resistant S. aureus , 57.1% (6/14) were gentamicin resistant and 35.7% (5/14) were resistant to more than 4 families of antibiotics. S. aureus carriers showed higher frequency of rhinitis (p=0.022 OR=6.6 (1.2-34.4)). Seven methicillin resistant S. aureus isolates were analyzed by Multiple-Locus Variable Analysis and two showed identical pattern bands. Conclusion: According to the results we found a high frequency of methicillin resistant S. aureus colonization and the presence of two isolates with identical profiles Multiple-Locus Variable Analysis, could  denote the possibility of a transmission between patients. Key Words: Staphylococcus aureus , Hemodialysis, Antibiotic resistance, bacterial typing (Source: MeSH-NLM).