Performance characteristics of a quantitative PCR assay on repository stool specimens and smeared filter-paper cards.

Objective: Stool repositories are a valuable resource for retrospective analyses including quantitative PCR assays to distinguish between asymptomatic shedding and clinical disease. The suitability of archival specimens for this purpose is unclear and requires assessment. We conducted a pilot study to evaluate pathogen detection by TaqMan Array Card (TAC) in travelers' diarrhea (TD) stool specimens stored for 1-13 years, as well as the impact of transporting specimens on Whatman FTA Elute cards (FTA Cards) on detection.

Distribution of Capsular Types of Isolates from Symptomatic and Asymptomatic Children in Peru.

is the leading bacterial cause of diarrhea worldwide. A capsular polysaccharide (CPS) conjugate vaccine is under development and requires determination of the valency. However, distribution of CPS types circulating globally is presently poorly described.

Enhanced Immunogenicity and Protective Efficacy of a Conjugate Vaccine Coadministered with Liposomes Containing Monophosphoryl Lipid A and QS-21.

is among the most common causes of diarrheal disease worldwide and efforts to develop protective measures against the pathogen are ongoing. One of the few defined virulence factors targeted for vaccine development is the capsule polysaccharide (CPS). We have developed a capsule conjugate vaccine against strain 81-176 (CPS-CRM) that is immunogenic in mice and nonhuman primates (NHPs) but only moderately immunogenic in humans when delivered alone or with aluminum hydroxide.

Campylobacter jejuni transcriptional and genetic adaptation during human infection.

Campylobacter jejuni infections are a leading cause of bacterial food-borne diarrhoeal illness worldwide, and Campylobacter infections in children are associated with stunted growth and therefore long-term deficits into adulthood. Despite this global impact on health and human capital, how zoonotic C. jejuni responds to the human host remains unclear.

Promiscuous and adaptable enzymes fill "holes" in the tetrahydrofolate pathway in Chlamydia species.

Folates are tripartite molecules comprising pterin, para-aminobenzoate (PABA), and glutamate moieties, which are essential cofactors involved in DNA and amino acid synthesis. The obligately intracellular Chlamydia species have lost several biosynthetic pathways for essential nutrients which they can obtain from their host but have retained the capacity to synthesize folate. In most bacteria, synthesis of the pterin moiety of folate requires the FolEQBK enzymes, while synthesis of the PABA moiety is carried out by the PabABC enzymes.

DNA prime/Adenovirus boost malaria vaccine encoding P. falciparum CSP and AMA1 induces sterile protection associated with cell-mediated immunity.

Background: Gene-based vaccination using prime/boost regimens protects animals and humans against malaria, inducing cell-mediated responses that in animal models target liver stage malaria parasites. We tested a DNA prime/adenovirus boost malaria vaccine in a Phase 1 clinical trial with controlled human malaria infection.

Methodology/principal Findings: The vaccine regimen was three monthly doses of two DNA plasmids (DNA) followed four months later by a single boost with two non-replicating human serotype 5 adenovirus vectors (Ad).

Differential regulation of caspase-1 activation via NLRP3/NLRC4 inflammasomes mediated by aerolysin and type III secretion system during Aeromonas veronii infection.

Aeromonas spp. are Gram-negative bacteria that cause serious infectious disease in humans. Such bacteria have been shown to induce apoptosis in infected macrophages, yet the host responses triggered by macrophage death are largely unknown.

Cytotoxins of the human pathogen Aeromonas hydrophila trigger, via the NLRP3 inflammasome, caspase-1 activation in macrophages.

Aeromonas hydrophila is a Gram-negative pathogen that causes serious infectious disease in humans. A. hydrophila induces apoptosis in infected macrophages, but the host proinflammatory responses triggered by macrophage death are largely unknown.

Pathogenic Vibrio activate NLRP3 inflammasome via cytotoxins and TLR/nucleotide-binding oligomerization domain-mediated NF-kappa B signaling.

Vibrio vulnificus and Vibrio cholerae are Gram-negative pathogens that cause serious infectious disease in humans. The beta form of pro-IL-1 is thought to be involved in inflammatory responses and disease development during infection with these pathogens, but the mechanism of beta form of pro-IL-1 production remains poorly defined. In this study, we demonstrate that infection of mouse macrophages with two pathogenic Vibrio triggers the activation of caspase-1 via the NLRP3 inflammasome.

L,L-diaminopimelate aminotransferase, a trans-kingdom enzyme shared by Chlamydia and plants for synthesis of diaminopimelate/lysine.

The synthesis of meso-diaminopimelic acid (m-DAP) in bacteria is essential for both peptidoglycan and lysine biosynthesis. From genome sequencing data, it was unclear how bacteria of the Chlamydiales order would synthesize m-DAP in the absence of dapD, dapC, and dapE, which are missing from the genome. Here, we assessed the biochemical capacity of Chlamydia trachomatis serovar L2 to synthesize m-DAP.

Building the invisible wall: updating the chlamydial peptidoglycan anomaly.

The existence of peptidoglycan (PG) in chlamydiae has long been debated. Genome sequencing of members of the Chlamydiaceae family and Protochlamydia amoebophila has uncovered a nearly complete pathway for PG synthesis in these organisms. The recent use of microarray and proteomic analysis methods has revealed that PG synthesis genes are expressed primarily during reticulate body development and division.

Characterization of Chlamydia MurC-Ddl, a fusion protein exhibiting D-alanyl-D-alanine ligase activity involved in peptidoglycan synthesis and D-cycloserine sensitivity.

Recent characterization of chlamydial genes encoding functional peptidoglycan (PG)-synthesis proteins suggests that the Chlamydiaceae possess the ability to synthesize PG yet biochemical evidence for the synthesis of PG has yet to be demonstrated. The presence of D-amino acids in PG is a hallmark of bacteria. Chlamydiaceae do not appear to encode amino acid racemases however, a D-alanyl-D-alanine (D-Ala-D-Ala) ligase homologue (Ddl) is encoded in the genome.

In vitro and in vivo functional activity of Chlamydia MurA, a UDP-N-acetylglucosamine enolpyruvyl transferase involved in peptidoglycan synthesis and fosfomycin resistance.

Organisms of Chlamydia spp. are obligate intracellular, gram-negative bacteria with a dimorphic developmental cycle that takes place entirely within a membrane-bound vacuole termed an inclusion. The chlamydial anomaly refers to the fact that cell wall-active antibiotics inhibit Chlamydia growth and peptidoglycan (PG) synthesis genes are present in the genome, yet there is no biochemical evidence for synthesis of PG.

Identification and genetic characterization of PmrA-regulated genes and genes involved in polymyxin B resistance in Salmonella enterica serovar typhimurium.

Salmonella enterica serovar Typhimurium encounters antimicrobial peptides (AP) within the phagosomes of professional phagocytes and at intestinal mucosal surfaces. Salmonella serovar Typhimurium utilizes the two-component regulatory system PmrA-PmrB, which is activated in response to the environmental conditions encountered in vivo, to regulate resistance to several AP, including polymyxin B (PM). Random MudJ transposon mutagenesis was used to identify PmrA-PmrB-regulated genes, as well as genetic loci necessary for PM resistance.