Statistics and Probability (1)
Epidemiology & Infection (1)
Infection Control & Hospital Epidemiology (1)
Society for Healthcare Epidemiology of America (SHEA) (1)
Molecular Characterization of Methicillin-Resistant Staphylococcus aureus Disseminated in a Home Care System
R. Rozenbaum, M. C. Silva-Carvalho, R. R. Souza, M. C. N. Melo, C. N. Gobbi, L. R. Coelho, R. L. Ferreira, B. T. Ferreira-Carvalho, A. L. Schuenck, F. M. C. S. Neves, L. R. P. O. F. Silva, A. M. S. Figueiredo
Journal: Infection Control & Hospital Epidemiology / Volume 27 / Issue 10 / October 2006
Print publication: October 2006
Objective.
To study colonization with methicillin-resistant Staphylococcus aureus in a home care service during a 4-month period.
Prospective study.
Setting.
A home care service located in Rio de Janeiro, Brazil.
Patients admitted to the home care service during this period, their household contacts, and health care workers (HCWs).
Swab specimens from the anterior nares were collected from each patient in the 3 groups at admission. Screening was repeated every 7 days. MRSA was detected using a mecA probe, and the clonality of isolates was evaluated by molecular methods, primarily pulsed-field gel electrophoresis.
Of the 59 study patients, 9 (15.3%) had MRSA colonization detected; these cases of colonization were classified as imported. Only 1 (2.0%) of the 50 patients not colonized at admission became an MRSA carrier (this case of colonization was classified as autochthonous). Two (0.9%) of 224 household contacts and 16 (7.4%) of 217 HCWs had MRSA colonization. Cross-transmission from patient to HCW could be clearly demonstrated in 8 cases. The great majority of MRSA isolates belonged to the Brazilian epidemic clone.
Conclusions.
MRSA colonization was common in the home care service analyzed. The fact that the majority of MRSA isolates obtained were primarily of nosocomial origin (and belonged to the so-called Brazilian epidemic clone) substantiated our findings that all but 1 patient had already been colonized before admission to the home care service. Only cross-transmission from patients to healthcare workers could be verified. On the basis of these results, we believe that a control program built on admission screening of patients for detection of MRSA carriage could contribute to the overall quality of care.
Isolation and molecular characterization of methicillin-resistant coagulase-negative staphylococci from nasal flora of healthy humans at three community institutions in Rio de Janeiro City
F. R. SILVA, E. M. MATTOS, M. V. S. COIMBRA, B. T. FERREIRA-CARVALHO, A. M. S. FIGUEIREDO
Journal: Epidemiology & Infection / Volume 127 / Issue 1 / August 2001
Published online by Cambridge University Press: 28 August 2001, pp. 57-62
We describe the isolation and molecular characterization of methicillin-resistant coagulase-negative staphylococci (MRCNS) from the nasal flora of healthy humans from three institutions located in Rio de Janeiro City. Swabs were obtained from the nares of students attending a non-residential public school and adults from two military quarters. Isolates of staphylococci were tested for the presence of the mecA gene by hybridization with a specific probe. S. epidermidis was the most frequent MRCNS (38 of the total 45 CNS isolated). Twenty-five percent of nasal staphylococcal carriers studied were colonized with MRCNS. Pulsed-field gel electrophoresis (PFGE) of SmaI-digested genomic DNA was carried out to study the clonality of the methicillin-resistant S. epidermidis (MRSE) isolates. In addition to cross-colonization among individuals belonging to the same institution, familial cross-colonization appeared to contribute to the spread of the methicillin-resistant isolates among two inter-communicable institutions. Indeed, the wide genomic diversity among the MRSE flora suggests that the spread of the mecA gene among these isolates might also have occurred via horizontal transmission. Despite the limited number of institutions analysed, it is reasonable to conclude that our data do not represent a situation unique to the three organizations but may reflect other communities in Rio with respect to transmission of MRCNS.