Results of a pilot multicenter genotype-based randomized placebo-controlled trial of propranolol to reduce pain after major thermal burn injury.

BACKGROUND: Results of previous studies suggest that ß-adrenoreceptor activation may augment pain, and that ß-adrenoreceptor antagonists may be effective in reducing pain, particularly in individuals not homozygous for the catechol-O-methyltransferase (COMT) high-activity haplotype. MATERIALS AND METHODS: Consenting patients admitted for thermal burn injury at participating burn centers were genotyped; those who were not high-activity COMT homozygotes were randomized to propranolol 240 mg/d or placebo. Primary outcomes were study feasibility (consent rate, protocol completion rate) and pain scores on study days 5 to 19. Secondary outcomes assessed pain and posttraumatic stress disorder symptoms 6 weeks postinjury. RESULTS: Seventy-seven percent (61/79) of eligible patients were consented and genotyped, and 77% (47/61) were genotype eligible and randomized. Ninety-one percent (43/47) tolerated study drug and completed primary outcome assessments. In intention-to-treat and per-protocol analyses, patients randomized to propranolol had worse pain scores on study days 5 to 19. CONCLUSIONS: Genotype-specific pain medication interventions are feasible in hospitalized burn patients. Propranolol is unlikely to be a useful analgesic during the first few weeks after burn injury.

A study of the enterotoxigenicity of coagulase-negative and coagulase-positive staphylococcal isolates from food poisoning outbreaks in Minas Gerais, Brazil.

OBJECTIVES: The purpose of this study was to identify enterotoxin genes from isolates of coagulase-negative staphylococci and coagulase-positive staphylococci obtained from dairy products, responsible for 16 outbreaks of food poisoning. METHODS: From the pool of 152 staphylococcal isolates, 15 coagulase-negative and 15 coagulase-positive representatives were selected for this study. The 15 coagulase-negative isolates were tested for the presence of coa and femA genes, which are known to be characteristic of Staphylococcus aureus. After testing for enterotoxin genes by polymerase chain reaction (PCR), the 30 selected isolates were tested for the presence of toxin by immunoassay. RESULTS: Seven of the coagulase-negative isolates amplified the coa gene and were subsequently reclassified as coagulase-positive. Twenty-one of 30 selected isolates had staphylococcal enterotoxin genes and most of these produced toxin as well. The most frequently encountered enterotoxin genes were sea and seb. Among eight coagulase-negative isolates, five had enterotoxin genes, all of which were found to have detectable toxin by immunoassay. CONCLUSIONS: The results from this study demonstrate that coagulase-negative as well as coagulase-positive staphylococci isolated from dairy products are capable of genotypic and phenotypic enterotoxigenicity. Furthermore, these data demonstrate that PCR is a sensitive and specific method for screening outbreak isolates regardless of coagulase expression.

A case study of a massive staphylococcal food poisoning incident.

In the summer of 1998, approximately 8000 individuals gathered to celebrate a Catholic priest's ordination in Minas Gerais, Brazil. Within hours of food consumption, 4000 patients experienced acute gastroenteritis, and approximately 2000 (50%) overwhelmed Emergency Departments of 26 local hospitals. Of the triaged patients, 396 ( approximately 20%) required subsequent admission, and of these patients, 81 ( approximately 20%) were admitted to intensive care units. A total of 16 ( approximately 20% of those admitted to the ICU) patients progressed on to develop irreversible multi-system shock and expired while hospitalized. The trace-back investigation implicated food preparers who were culture positive for enterotoxigenic Staphylococcus aureus as the source of contamination. This study provides information on the magnitude and severity of oral exposure to Staphylococcal enterotoxin.