Brian H. Raphael

Learn More
Campylobacter jejuni, a gram-negative motile bacterium, secretes a set of proteins termed the Campylobacter invasion antigens (Cia proteins). The purpose of this study was to determine whether the flagellar apparatus serves as the export apparatus for the Cia proteins. Mutations were generated in five genes encoding three structural components of the(More)
Botulism due to type F botulinum neurotoxin (BoNT/F) is rare (<1% of cases), and only a limited number of clostridial strains producing this toxin type have been isolated. As a result, analysis of the diversity of genes encoding BoNT/F has been challenging. In this study, the entire bont/F nucleotide sequences were determined from 33 type F botulinum(More)
Mental health is becoming a central issue for public health complex emergencies. In this review we present a culturally valid mental health action plan based on scientific evidence that is capable of addressing the mental health effects of complex emergencies. A mental health system of primary care providers, traditional healers, and relief workers, if(More)
Two-component regulatory systems play a major role in the physiological response of bacteria to environmental stimuli. Such systems are composed of a sensor histidine kinase and a response regulator whose ultimate function is to affect the expression of target genes. Response regulator mutants of Campylobacter jejuni strain F38011 were screened for(More)
Botulism is a potentially fatal paralytic disease caused by the action of botulinum neurotoxin (BoNT) on nerve cells. There are 7 known serotypes (A-G) of BoNT and up to 40 genetic variants. Clostridium botulinum strain IBCA10-7060 was recently reported to produce BoNT serotype B (BoNT/B) and a novel BoNT, designated as BoNT/H. The BoNT gene (bont) sequence(More)
Neurotoxin cluster gene sequences and arrangements were elucidated for strains of Clostridium botulinum encoding botulinum neurotoxin (BoNT) subtypes A3, A4, and a unique A1-producing strain (HA(-) Orfx(+) A1). These sequences were compared to the known neurotoxin cluster sequences of C. botulinum strains that produce BoNT/A1 and BoNT/A2 and possess either(More)
A focused oligonucleotide microarray featuring 62 probes targeting strain variable regions of the Clostridium botulinum strain ATCC 3502 genome sequence was developed to differentiate C. botulinum type A strains. The strain variable regions were selected from deletions identified among a panel of 10 type A strains compared to the strain ATCC 3502 genome(More)
We report that C. jejuni modifies its outer membrane protein (OMP) repertoire when cultivated under iron-limiting conditions such as during incubation with epithelial cells. To identify genes encoding de novo expressed OMPs, a C. jejuni cosmid library was screened with antisera raised against proteins expressed in the presence of epithelial cells. A single(More)
Taxonomic classification of Clostridium botulinum is based on the production of botulinum neurotoxin (BoNT), while closely related, nontoxic organisms are classified as Clostridium sporogenes. However, this taxonomic organization does not accurately mirror phylogenetic relationships between these species. A phylogenetic reconstruction using 2,016(More)
Botulinum neurotoxin (BoNT) producing clostridia contain genes encoding a specific neurotoxin serotype (A-G) and nontoxic associated proteins that form the toxin complex. The nontoxic nonhemagglutinin (NTNH) is a conserved component of the toxin complex in all seven toxin types. A real-time PCR assay that utilizes a locked nucleic acid hydrolysis probe to(More)