An unidentified agent was cultured in primary monkey cells at the Los Angeles County Public HealthDepartment from each of five stool specimens submitted from an outbreak of gastroenteritis. Electron microscopy and an adenovirus-specific monoclonal antibody confirmed this agent to be an adenovirus. Since viral titers were too low, complete serotyping was not possible. Using the DNase-sequence-independent viral nucleic acid amplification method, we identified several nucleotide sequences with a high homology to human adenovirus 41 (HAdV-41) and simian adenovirus 1 (SAdV-1). However, using anti-SAdV-1 sera, it was determined that this virus was serologically different than SAdV-1. Genomic sequencing and phylogenetic analysis confirmed that this new adenovirus was so divergent from the known human adenoviruses that it was not only a new type but also represented a new species (human adenovirus G). In a retrospective clinical study, this new virus was detected by PCR in one additional patient from a separate gastroenteritis outbreak. This study suggests that HAdV-52 may be one of many agents causing gastroenteritis of unknown etiology.

Clostridium perfringens is one of the etiologic agents of gas gangrene that can occur when a wound is contaminated with soil. Type A C. perfringens can cause foodborne and nonfoodborne gastrointestinal illnesses due to an enterotoxin (CPE) produced by some strains during sporulation. We developed a quantitative real-time PCR assay based on fluorescence resonance energy transfer hybridization chemistry that targets the C. perfringens-specific phospholipase C (plc) gene and the enterotoxigenic gene (cpe) with the LightCycler and the Ruggedized Advanced Pathogen Identification Device (R.A.P.I.D.). The assay can detect as few as 20 copies of target sequences per PCR. The total assay time, from extraction to PCR analysis, is 90 min. This assay is rapid, sensitive, and specific and will allow direct detection of C. perfringens in water, food, and stool samples. It should prove helpful in investigating foodborne illnesses due to C. perfringens and can be used as a tool to ensure the safety of food and water supplies.