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Objective. To describe the analysis of geographical and temporal distribution of DNA profiles determined by pulsed-field gel electrophoresis (PFGE) of methicillin-resistant Staphylococcus aureus (MRSA) strains isolated from hospitalized patients in a tertiary care university hospital in Brazil. Methods. Ninety-nine samples of MRSA obtained from 89 patients in the period 1999-2004 were studied. MRSA strains were isolated from central venous catheters (33 isolates) and bloodstream infections (66 strains). PFGE with 20 units of SmaI restriction endonuclease was used for genomic typing. Results. Analysis of DNA PFGE of 99 strains of MRSA revealed 26 profiles and their respective related profiles. The mean time interval for detecting MRSA infection was 26 days from hospital admission. Forty-nine patients (57.6%) had a recent hospitalization. The DNA PFGE MRSA profiles were distributed in three clonal groups--I, II, and III--according to the period of time when the MRSA strains were isolated. DNA PFGE MRSA profiles were spread homogeneously through all hospital wards. Conclusions. Changes in the distribution of DNA PFGE MRSA profiles were largely temporal, with clonal groups being replaced over time, without predominance in any hospital ward or any specific area of the hospital. [ABSTRACT FROM AUTHOR]

Objectives: Based on pulsed-field gel electrophoresis (PFGE) profile, whole-genome sequencing (WGS) of eight carbapenem-resistant Pseudomonas aeruginosa isolates from a bone marrow transplant unit in São Paulo, Brazil, was performed to investigate the presence of resistance and virulence genes as well as to determine the sequence type (ST) by multilocus sequence typing (MLST)., Methods: The initial phenotypic susceptibility pattern of the isolates was determined by VITEK ® 2. Minimum inhibitory concentrations (MICs) were determined by the broth microdilution method for amikacin, meropenem and colistin. WGS was performed using an Illumina MiSeq system. A Galleria mellonella infection model was used to evaluate the virulence of the strains., Results: WGS demonstrated that mutations in genes encoding outer membrane proteins and efflux pumps in an isolate harbouring bla VIM-36 (ST308) differed from those in isolates harbouring bla SPM (ST277). The mexT gene harboured a mutation resulting in a frameshift in all isolates; in addition, the oprD gene of the bla VIM-36 -carrying isolate had an insertion leading to a frameshift. Virulence genes did not differ between ST277 and ST308 strains. Moreover, only two isolates harbouring bla SPM showed virulence in the G. mellonella model, killing 100% of larvae after 18-24h., Conclusions: P. aeruginosa carrying bla VIM-36 belonging to ST308 was identified for the first time in our hospital. Although the virulence gene profiles were similar in isolates carrying bla SPM and the isolate carrying bla VIM-36 , only two isolates harbouring bla SPM showed virulence in the G. mellonella model., (Copyright © 2018 International Society for Chemotherapy of Infection and Cancer. Published by Elsevier Ltd. All rights reserved.)

Objective: To describe the analysis of geographical and temporal distribution of DNA profiles determined by pulsed-field gel electrophoresis (PFGE) of methicillin-resistant Staphylococcus aureus (MRSA) strains isolated from hospitalized patients in a tertiary care university hospital in Brazil., Methods: Ninetynine samples of MRSA obtained from 89 patients in the period 1999-2004 were studied. MRSA strains were isolated from central venous catheters (33 isolates) and bloodstream infections (66 strains). PFGE with 20 units of SmaI restriction endonuclease was used for genomic typing., Results: Analysis of DNA PFGE of 99 strains of MRSA revealed 26 profiles and their respective related profiles. The mean time interval for detecting MRSA infection was 26 days from hospital admission. Forty-nine patients (57.6%) had a recent hospitalization. The DNA PFGE MRSA profiles were distributed in three clonal groups-I, II, and III-according to the period of time when the MRSA strains were isolated. DNA PFGE MRSA profiles were spread homogeneously through all hospital wards., Conclusions: Changes in the distribution of DNA PFGE MRSA profiles were largely temporal, with clonal groups being replaced over time, without predominance in any hospital ward or any specific area of the hospital.