Inoculum Preparation Conditions Influence Adherence of Salmonella enterica Serovars to Red Leaf Lettuce (Lactuca sativa).

ABSTRACT: Salmonella enterica has been increasingly linked to outbreaks involving consumption of fresh produce. Although researchers have identified genes whose products are involved in mediating S. enterica-plant interactions, the use of various experimental approaches, serovars, and plant types has generated variable and conflicting data. The purpose of this study was to determine whether conditions under which inocula are prepared for in vitro plant interaction studies influence the outcome of these studies. Seven S. enterica serovars were grown in media that differed in salinity and physical state with incubation at 25 or 37°C. These cultures were then used to inoculate red leaf lettuce, and adherent microbes were subsequently recovered. Although all Salmonella serovars were influenced by inoculum preparation conditions, the amount of variation differed. Analysis of pooled serovar data revealed that inocula prepared from either agar plates or biphasic cultures had higher levels of interaction with red leaf lettuce than those prepared from broth cultures. Incubation at 37°C enhanced adherence after 30 s or 5 days of contact time, and adherence after 1 h of contact time was increased in low-salt medium. Broth inoculum cultures were highly influenced by medium salinity and incubation temperature, whereas plate and biphasic inoculum cultures were only minimally affected. Therefore, inocula prepared from bacteria grown on plates or in biphasic culture would be most suitable for evaluation of strategies used to interfere with plant-Salmonella interactions. However, pooled data mask serovar-specific responses, and care should be taken when extrapolating these findings to individual serovars. The previous association of a serovar with outbreaks involving leafy greens was not correlated with levels of interaction with red leaf lettuce, suggesting that the occurrence of these serovars in or on these commodities does not reflect their fitness in the plant environment.

Training subspecialty nurses in developing countries: methods, outcome, and cost.

BACKGROUND: As infections are controlled in developing countries, other pediatric subspeciality programs such as oncology become increasingly important. A major impediment to the development of such programs is a lack of trained nurses. Therefore, education of pediatric subspecialty nurses becomes a priority. PROCEDURE: We describe three models we have used for education of pediatric oncology nurses: a short series of classes or lectures with additional training of key nurses, an expanded 12 week series of classes at centers combining didactic and clinical instruction and a regional residential school offering regular 12 week courses in theory and clinical practice. RESULTS: Cost analysis showed that the cost per nurse trained was, respectively, 3,700; 4,350; and 5,500 US dollars. Early effectiveness indicators show that retention rates are high, home institutions are satisfied, and nurses trained shared their knowledge with other nurses and improved nursing practices. CONCLUSIONS: Programs to teach subspecialty nursing in developing countries are effective and can improve medical care. Such programs should be based on past experience and evaluated as to cost and effectiveness.

International hematology-oncology nursing education in Latin America.

In countries with limited resources, the multidisciplinary hematology-oncology (H-O) treatment team model, which relies heavily on highly trained nurses, is generally not in use. Since 1996, St. Jude Children's Research Hospital has been working with medical centers in Mexico and Central and South America to improve the specialty training of nurses in pediatric H-O. In 1999, St. Jude developed a strategic plan to organize a cooperative nursing education project. The initial preparation consisted of three phases. In phase one, a curriculum was developed. A consultant was hired to create and institute an evaluation system for nurse graduates of the program and for the program itself. Phase two explored the possible collaborations among existing training centers and contracted with a nurse educator to provide on-site support. In phase three, a core team of skilled multicultural nursing educators was formed. To initiate the program, we used the "Teach the Teachers" method. Four classes to date have trained 76 nurses from different countries in Latin America. Development of the International Training Center for Hematology-Oncology Nurses in Latin America has been a challenging and rewarding experience. We hope that others will find it useful in planning international education programs that will not only serve the nursing profession, but also improve the quality of care of all children, regardless of their background, race, religion, or economic status.