Clostridium difficile is the leading cause of nosocomial antibiotic-associated diarrhea, and recent outbreaks of strains with increased virulence underscore the importance of identifying novel approaches to treat and prevent relapse of Clostridium difficile-associated diarrhea (CDAD). CDAD pathology is induced by two exotoxins, toxin A and toxin B, which have been shown to be cytotoxic and, in the case of toxin A, enterotoxic. In this report we describe fully human monoclonal antibodies (HuMAbs) that neutralize these toxins and prevent disease in hamsters. Transgenic mice carrying human immunoglobulin genes were used to isolate HuMAbs that neutralize the cytotoxic effects of either toxin A or toxin B in cell-based in vitro neutralization assays. Three anti-toxin A HuMAbs (3H2, CDA1, and 1B11) could all inhibit the enterotoxicity of toxin A in mouse intestinal loops and the in vivo toxicity in a systemic mouse model. Four anti-toxin B HuMAbs (MDX-1388, 103-174, 1G10, and 2A11) could neutralize cytotoxicity in vitro, although systemic toxicity in the mouse could not be neutralized. Anti-toxin A HuMAb CDA1 and anti-toxin B HuMAb MDX-1388 were tested in the well-established hamster model of C. difficile disease. CDA1 alone resulted in a statistically significant reduction of mortality in hamsters; however, the combination treatment offered enhanced protection. Compared to controls, combination therapy reduced mortality from 100% to 45% (P < 0.0001) in the primary disease hamster model and from 78% to 32% (P < 0.0001) in the less stringent relapse model.

A whole-cell killed unencapsulated pneumococcal vaccine given by the intranasal route with cholera toxin as an adjuvant was tested in two animal models. This vaccination was highly effective in preventing nasopharyngeal colonization with an encapsulated serotype 6B strain in mice and also conferred protection against illness and death in rats inoculated intrathoracically with a highly encapsulated serotype 3 strain. When the serotype 3 challenge strain was incubated in the sera of immunized rats, it was no longer virulent in an infant-rat sepsis model, indicating that the intranasal immunization elicited protective systemic antibodies. These studies suggest that killed whole-cell unencapsulated pneumococci given intranasally with an adjuvant may provide multitypic protection against capsulated pneumococci.Streptococcus pneumoniae (pneumococcus) annually causes 10 million deaths worldwide, including the deaths of 1 million children in low-income countries (26). Type-specific immunity, based on the capsular polysaccharides (PS), is well established (20). The licensed 23-valent PS vaccine, however, is not efficacious in children younger than 2 years. The newly licensed heptavalent PS conjugate vaccine protects against 90% of pneumococcal invasive disease in infancy in the United States (28) but includes fewer serotypes than the PS vaccine and omits several that are prevalent worldwide (10). Other drawbacks of the conjugate vaccine include a limited effect on otitis media (2, 11), high costs, and the potential for serotype replacement, which has already been suggested in recent clinical trials (11, 17; R. Dagan, N. Givon, P. Yagupsky, N. Porat, J. Janco, I. Chang, et al., Program Abstr. 38th Intersci. Conf. Antimicrob. Agents Chemother., abstr. S52, 1998).Several investigators have identified protective antigens common to pneumococci of many or all serotypes. Several such "species" antigens in purified or vectored form have shown protection in animal models (4-6, 8, 18, 19, 23, 25), but it is uncertain whether, when, and at what cost any of these will be developed as an effective vaccine for humans, particularly in low-income countries. As an alternative presentation of species antigens, we have studied unencapsulated whole cells, which should present a number of such antigens in native configuration unoccluded by capsule. In addition, the intranasal route of immunization might elicit mucosal immunity and, with suitable adjuvant, systemic immunity as well. Finally, of importance to low-income countries, a mucosally administered whole-cell preparation has the possible advantage of low cost of production and administration, without the need for sterile injection devices. In the present study we tested killed, unencapsulated cells applied intranasally with cholera toxin (CT) as an adjuvant (R. Malley, S. Pelton, A. Stack, R. Saladino, D. E. Briles, and P. Anderson, 2nd Int. Symp. Pneumococci Pneumococcal Dis., abstr. P25, 2000), using two animal models: nasopharyngeal colonization of mice with type 6B and lethal intrat...

No abstract

BACKGROUND AND OBJECTIVES:Few studies have demonstrated improvement in adherence to Pediatric Advanced Life Support guidelines for severe sepsis and septic shock. We sought to improve adherence to national guidelines for children with septic shock in a pediatric emergency department with poor guideline adherence. METHODS:Prospective cohort study of children presenting to a tertiary care pediatric emergency department with septic shock. Quality improvement (QI) interventions, including repeated plan-do-study-act cycles, were used to improve adherence to a 5-component sepsis bundle, including timely (1) recognition of septic shock, (2) vascular access, (3) administration of intravenous (IV) fluid, (4) antibiotics, and (5) vasoactive agents. The intervention focused on IV fluid delivery as a key driver impacting bundle adherence, and adherence was measured using statistical process control methodology.RESULTS: Two-hundred forty-two patients were included: 126 subjects before the intervention (November 2009 to March 2011), and 116 patients during the QI intervention (October 2011 to May 2013). We achieved 100% adherence for all metrics, including (1) administration of 60 mL/kg IV fluid within 60 minutes (increased from baseline adherence rate of 37%), (2) administration of vasoactive agents within 60 minutes (baseline rate of 35%), and (3) 5-component bundle adherence (baseline rate of 19%). Improvement was sustained over 9 months. The number of septic shock cases between each death from this condition increased after implementation of the QI intervention.CONCLUSIONS: Using QI methodology, we have demonstrated improved adherence to national guidelines for severe sepsis and septic shock.