Molecular epidemiology of methicillin-resistant Staphylococcus aureus in nursing homes: a cross-sectional study.

A cross-sectional study of methicillin-resistant Staphylococcus aureus carriage in 2,857 nursing home residents showed an overall prevalence of 4.9%. The three clones identified by genetic analysis were identical to those in the acute care facilities; only their relative prevalence differed.

Staphylococcus aureus adherence to nasal epithelial cells in a physiological in vitro model.

Nasal carriage of Staphylococcus aureus represents a risk factor for subsequent invasive infections and interpatient transmission of strains. No physiological in vitro model of nasal epithelial cells is available to study both patient- and bacteria-related characteristics and their interaction, leading to adherence and colonization. Starting with tissues from human nasal polyps, a confluent, squamous, nonkeratinized epithelium in collagen-coated 96-well microtiter plates was obtained after 14 d.

Amplified-fragment length polymorphism analysis versus macro-restriction fragment analysis for molecular typing of Streptococcus pneumoniae isolates.

Forty-eight pneumococci were genotyped by on-line laser fluorescence amplified-fragment length polymorphism (AFLP) and pulsed-field gel electrophoresis (PFGE) analysis of chromosomal restriction fragments. Overall, the data generated by the two methods corresponded well. However, with AFLP, clusters were delineated at a higher similarity level, and isolate differentiation was more pronounced.

Increase in penicillin resistance rates in Belgium due to clonal spread of a penicillin-resistant 23F Streptococcus pneumoniae strain.

In 1994 a sudden increase in penicillin resistance was observed in Belgium among invasive pneumococci. To determine whether this increase was due to clonal spread of a resistant strain or to de novo acquisition of penicillin resistance, pneumococci of capsular types 23F, 19, 14, 9, and 6 isolated in 1993 and 1994, were analyzed by capsular serotyping and DNA macrorestriction analysis, resolved by pulsed-field gel electrophoresis. Furthermore, pneumococcal isolates from northern France, a region with a high prevalence of penicillin resistance, and from southern Belgium, a region with a low but increasing prevalence of penicillin resistance, were analyzed.

Clonal analysis and identification of epidemic strains of methicillin-resistant Staphylococcus aureus by antibiotyping and determination of protein A gene and coagulase gene polymorphisms.

Forty-three methicillin-resistant Staphylococcus aureus (MRSA) isolates with known genetic and epidemiological relatedness and different degrees of transmission were analyzed by antibiotyping, protein A gene polymorphism analysis, and coagulase gene polymorphism analysis. The three typing systems were evaluated for their performance and convenience to define clones and to discriminate between epidemic MRSA (EMRSA) and sporadic MRSA (SMRSA). Antibiotyping and AluI restriction fragment length polymorphism analysis of the coagulase gene were able to define clones in the same way as DNA macrorestriction analysis (SmaI).