Dissemination of methicillin-resistant Staphylococcus aureus USA300 sequence type 8 lineage in Latin America.

BACKGROUND: Methicillin-resistant Staphylococus aureus (MRSA) is an important nosocomial and community-associated (CA) pathogen. Recently, a variant of the MRSA USA300 clone emerged and disseminated in South America, causing important clinical problems. METHODS: S. aureus isolates were prospectively collected (2006-2008) from 32 tertiary hospitals in Colombia, Ecuador, Peru, and Venezuela. MRSA isolates were subjected to antimicrobial susceptibility testing and pulsed-field gel electrophoresis and were categorized as health care-associated (HA)-like or CA-like clones on the basis of genotypic characteristics and detection of genes encoding Panton-Valentine leukocidin and staphylococcal cassette chromosome (SCC) mec IV. In addition, multilocus sequence typing of representative isolates of each major CA-MRSA pulsotype was performed, and the presence of USA300-associated toxins and the arcA gene was investigated for all isolates categorized as CA-MRSA. RESULTS: A total of 1570 S. aureus were included; 651 were MRSA (41%)--with the highest rate of MRSA isolation in Peru (62%) and the lowest in Venezuela (26%)--and 71%, 27%, and 2% were classified as HA-like, CA-like, and non-CA/HA-like clones, respectively. Only 9 MRSA isolates were confirmed to have reduced susceptibility to glycopeptides (glycopeptide-intermediate S. aureus phenotype). The most common pulsotype (designated ComA) among the CA-like MRSA strains was found in 96% of isolates, with the majority (81%) having a < or =6-band difference with the USA300-0114 strain. Representative isolates of this clone were sequence type 8; however, unlike the USA300-0114 strain, they harbored a different SCCmec IV subtype and lacked arcA (an indicator of the arginine catabolic mobile element). CONCLUSION: A variant CA-MRSA USA300 clone has become established in South America and, in some countries, is endemic in hospital settings.

Development and evaluation of a video-based modeling strategy for the dissemination phase of a school health tobacco -use prevention program

Even the best school health education programs will be unsuccessful if they are not disseminated effectively in a manner that encourages classroom adoption and implementation. This study involved two components: (1) the development of a videotape intervention to be used in the dissemination phase of a 4-year, NCI-funded diffusion study and (2) the evaluation of that videotape intervention strategy in comparison with a print (information transfer) strategy. Conceptualization has been guided by Social Learning Theory, Diffusion Theory, and communication theory. Additionally, the PRECEDE Framework has been used. Seventh and 8th grade classroom teachers from Spring Branch Independent School District in west Houston participated in the evaluation of the videotape and print interventions using a 57-item preadoption survey instrument developed by the UT Center for Health Promotion Research and Development. Two-way ANOVA was used to study individual score differences for five outcome variables: Total Scale Score (comprised of 57 predisposing, enabling, and reinforcing items), Adoption Characteristics Subscale, Attitude Toward Innovation Subscale, Receptivity Toward Innovation, and Reinforcement Subscale. The aim of the study is to compare the effect upon score differences of video and print interventions alone and in combination. Seventy-three 7th and 8th grade classroom teachers completed the study providing baseline and post-intervention measures on factors related to the adoption and implementation of tobacco-use prevention programs. Two-way ANOVA, in relation to the study questions, found significant scoring differences for those exposed to the videotape intervention alone for both the Attitude Toward Innovation Subscale and the Receptivity to Adopt Subscale. No significant results were found to suggest that print alone influences favorable scoring differences between baseline and post-intervention testing. One interaction effect was found suggesting video and print combined are more effective for influencing favorable scoring differences for the Reinforcement for the Adoption Subscale.^ This research is unique in that it represents a newly emerging field in health promotion communications research with implications for Social Learning Theory, Diffusion Theory, and communication science that are applicable to the development of improved school health interventions. ^