Effect of the Synthetic Bile Salt Analog CamSA on the Hamster Model of Clostridium difficile Infection.

Clostridium difficile infection (CDI) is the leading cause of antibiotic-associated diarrhea and has gained worldwide notoriety due to emerging hypervirulent strains and the high incidence of recurrence. We previously reported protection of mice from CDI using the antigerminant bile salt analog CamSA. Here we describe the effects of CamSA in the hamster model of CDI. CamSA treatment of hamsters showed no toxicity and did not affect the richness or diversity of gut microbiota; however, minor changes in community composition were observed. Treatment of C. difficile-challenged hamsters with CamSA doubled the mean time to death, compared to control hamsters. However, CamSA alone was insufficient to prevent CDI in hamsters. CamSA in conjunction with suboptimal concentrations of vancomycin led to complete protection from CDI in 70% of animals. Protected animals remained disease-free at least 30 days postchallenge and showed no signs of colonic tissue damage. In a delayed-treatment model of hamster CDI, CamSA was unable to prevent infection signs and death. These data support a putative model in which CamSA reduces the number of germinating C. difficile spores but does not keep all of the spores from germinating. Vancomycin halts division of any vegetative cells that are able to grow from spores that escape CamSA.

[Mexican clinical practice guidelines of immunotherapy 2011]. / Guía Mexicana de Práctica Clínica de Inmunoterapia 2011.

BACKGROUND: Several international guidelines on immunotherapy exist, but they only apply partially in Mexico. The Mexican guideline of immunotherapy dates from 1998. OBJECTIVES: To establish clinical recommendations and suggestions for Allergy residents and specialists for skin testing and allergen immunotherapy based on evidence and Mexican expert opinion, according to the GRADE system. METHODS: The guidelines were developed following the methodology of a guideline for clinical practice starting with the formulation of clinical questions, in the context of Mexican environmental conditions and morbidity, with the participation of allergists from all regions of the country. External validation was obtained. Its development followed three steps: 1. formulation of 24 clinical questions. 2. Search for consensus on the answers among members of the Regional chapters of both Mexican Colleges of Allergists (CMICA and COMPEDIA) during regional meetings. 3. Literature search for articles related to the questions and grading of its quality according to GRADE. RESULTS: Based on the regional consensus, 116 articles and the safety, patient acceptance/ comfort and cost clinical recommendations and suggestions were developed on basic aspects of skin testing, subcutaneous and sublingual immunotherapy (patient preparation, vial preparation and application schedules) and the treatment of eventual adverse reactions. CONCLUSIONS: A clinical guideline was developed respecting particular methodology, validated by CMICA and COMPEDIA for its implementation among Mexican allergists. Several aspects deserve further study to improve scientific evidence. KEYWORDS: Allergen immunotherapy, subcutaneous immunotherapy, sublingual immunotherapy, skin testing, allergy diagnosis, rhinitis, asthma, atopic dermatitis, house dust mite, pollens, anaphylaxis, adrenaline, Mexico.