OSIRIS-REx Contamination Control Strategy and Implementation.

OSIRIS-REx will return pristine samples of carbonaceous asteroid Bennu. This article describes how pristine was defined based on expectations of Bennu and on a realistic understanding of what is achievable with a constrained schedule and budget, and how that definition flowed to requirements and implementation. To return a pristine sample, the OSIRIS-REx spacecraft sampling hardware was maintained at level 100 A/2 and <180 ng/cm of amino acids and hydrazine on the sampler head through precision cleaning, control of materials, and vigilance.

Expansion of the Clostridium perfringens toxin-based typing scheme.

Clostridium perfringens causes many different histotoxic and enterotoxic diseases in humans and animals as a result of its ability to produce potent protein toxins, many of which are extracellular. The current scheme for the classification of isolates was finalized in the 1960s and is based on their ability to produce a combination of four typing toxins - α-toxin, β-toxin, ε-toxin and ι-toxin - to divide C. perfringens strains into toxinotypes A to E.

Zoonotic Transfer of Clostridium difficile Harboring Antimicrobial Resistance between Farm Animals and Humans.

The emergence of as a significant human diarrheal pathogen is associated with the production of highly transmissible spores and the acquisition of antimicrobial resistance genes (ARGs) and virulence factors. Unlike the hospital-associated RT027 lineage, the community-associated RT078 lineage is isolated from both humans and farm animals; however, the geographical population structure and transmission networks remain unknown. Here, we applied whole-genome phylogenetic analysis of 248 RT078 strains from 22 countries.

Bacterial probiotics as an aid in the control of Clostridium difficile disease in neonatal pigs.

Although Clostridium difficile infection (CDI) is a common disease in swine, there is a lack of prevention strategies. The objectives of this study were to evaluate: i) the effectiveness of Lactobacillus spp. and ii) non-toxigenic C.

Diversity of Clostridium perfringens isolates from various sources and prevalence of conjugative plasmids.

Clostridium perfringens is an important pathogen, causing food poisoning and other mild to severe infections in humans and animals. Some strains of C. perfringens contain conjugative plasmids, which may carry antimicrobial resistance and toxin genes.

Clostridium sordellii genome analysis reveals plasmid localized toxin genes encoded within pathogenicity loci.

Background: Clostridium sordellii can cause severe infections in animals and humans, the latter associated with trauma, toxic shock and often-fatal gynaecological infections. Strains can produce two large clostridial cytotoxins (LCCs), TcsL and TcsH, related to those produced by Clostridium difficile, Clostridium novyi and Clostridium perfringens, but the genetic basis of toxin production remains uncharacterised.

Results: Phylogenetic analysis of the genome sequences of 44 strains isolated from human and animal infections in the UK, US and Australia placed the species into four clades.

Expression of the large clostridial toxins is controlled by conserved regulatory mechanisms.

The clostridia cause many human and animal diseases, resulting in significant morbidity and mortality. Host damage results from the action of potent exotoxins, an important group of which is the large clostridial toxins (LCTs) produced by Clostridium difficile, Clostridium sordellii, Clostridium perfringens and Clostridium novyi. Knowledge of the structure and function of these toxins has been attained, however, apart from C.

International Clostridium difficile animal strain collection and large diversity of animal associated strains.

Background: Clostridium difficile is an important cause of intestinal infections in some animal species and animals might be a reservoir for community associated human infections. Here we describe a collection of animal associated C. difficile strains from 12 countries based on inclusion criteria of one strain (PCR ribotype) per animal species per laboratory.

An investigation into the association between cpb2-encoding Clostridium perfringens type A and diarrhea in neonatal piglets.

To investigate the possible role of cpb2-positive type A Clostridium perfringens in neonatal diarrheal illness in pigs, the jejunum and colon of matched normal and diarrheic piglets from 10 farms with a history of neonatal diarrhea were examined grossly and by histopathology, and tested for C. perfringens, for C. perfringens beta2 (CPB2) toxin, as well as for Clostridium difficile toxins, Salmonella, enterotoxigenic Escherichia coli, rotavirus, transmissible gastroenteritis (TGE) virus, and coccidia.

Non-24-Hour Disorder in Blind Individuals Revisited: Variability and the Influence of Environmental Time Cues.

Study Objectives: To assess the interindividual and intraindividual variability in the circadian rhythms of blind individuals with non-24-h disorder and to quantify the influence of environmental time cues in blind subjects lacking entrainment (non-24-h individuals or N-24s).

Design: An observational study of 21 N-24s (11 females and 10 males, age 9-78 years) who kept a sleep/wake schedule of their choosing. Circadian phase was determined using the melatonin onset (MO) from plasma or saliva samples that were collected every 2 weeks.

First isolation of Clostridium perfringens type E from a goat with diarrhea.

A 2-day-old goat died suddenly after the onset of severe diarrhea. No specific gross lesions were observed except for a remarkably thin intestinal wall and watery intestinal contents. Histopathological analysis revealed large numbers of Gram-positive bacilli layered upon the intestinal epithelia of the small intestine.

Effect of age, dose and antibiotic therapy on the development of Clostridium difficile infection in neonatal piglets.

Piglet diarrhea is associated with increased pre-weaning mortality, poor growth rates, and variation in weight at weaning. Clostridium difficile is a known cause of enteric disease in neonatal piglets, yet risk factors associated with C. difficile infection in piglets are unknown.

Presence of Clostridium perfringens in retail chicken livers.

Chicken livers sold at grocery stores in Tucson, AZ, USA were examined for the presence of Clostridium perfringens. Results showed that 69.6% of sampled retail chicken livers were culture positive for C.

Diagnosing clostridial enteric disease in poultry.

The world's poultry industry has grown into a multibillion-dollar business, the success of which hinges on healthy intestinal tracts, which result in effective feed conversion. Enteric disease in poultry can have devastating economic effects on producers, due to high mortality rates and poor feed efficiency. Clostridia are considered to be among the most important agents of enteric disease in poultry.

Tuning and timing in mammalian type I hair cells and calyceal synapses.

Afferent nerve fibers in the central zones of vestibular epithelia form calyceal endings around type I hair cells and have phasic response properties that emphasize fast head motions. We investigated how stages from hair-cell transduction to calyceal spiking contribute tuning and timing to central (striolar)-zone afferents of the rat saccular epithelium. In an excised preparation, we deflected individual hair bundles with rigid probes driven with steps and sinusoids (0.

Identification of accessory genome regions in poultry Clostridium perfringens isolates carrying the netB plasmid.

Necrotic enteritis (NE) is an economically important disease of poultry caused by certain Clostridium perfringens type A strains. NE pathogenesis involves the NetB toxin, which is encoded on a large conjugative plasmid within a 42-kb pathogenicity locus. Recent multilocus sequence type (MLST) studies have identified two predominant NE-associated clonal groups, suggesting that host genes are also involved in NE pathogenesis.

Development of a consensus method for culture of Clostridium difficile from meat and its use in a survey of U.S. retail meats.

Three previously described methods for culture of Clostridium difficile from meats were evaluated by microbiologists with experience in C. difficile culture and identification. A consensus protocol using BHI broth enrichment followed by ethanol shock and plating to selective and non-selective media was selected for use, and all participating laboratories received hands-on training in the use of this method prior to study initiation.

Comparative virulence of clinical Brachyspira spp. isolates in inoculated pigs.

Classical swine dysentery is associated with the presence of the strongly beta-hemolytic Brachyspira hyodysenteriae. However, multiple Brachyspira spp. can colonize the porcine colon.

Development of an antigen-capture enzyme-linked immunosorbent assay for Clostridium perfringens beta2-toxin in porcine feces and the neonatal piglet intestine.

An enzyme-linked immunosorbent assay (ELISA) was developed for detection and quantitation of beta2-toxin in neonatal piglet intestinal contents. Polystyrene plates were coated with polyclonal capture antibodies prepared against consensus recombinant beta2-toxin. The ELISA was developed using consensus recombinant beta2-toxin, atypical recombinant beta2-toxin, purified consensus native beta2-toxin, and field samples of neonatal porcine intestinal contents.

Comparison of atypical Brachyspira spp. clinical isolates and classic strains in a mouse model of swine dysentery.

Multiple Brachyspira spp. can colonize the porcine colon, and the presence of the strongly beta-hemolytic Brachyspira hyodysenteriae is typically associated with clinical swine dysentery. Recently, several Brachyspira spp.

Genome sequencing and analysis of a type A Clostridium perfringens isolate from a case of bovine clostridial abomasitis.

Clostridium perfringens is a common inhabitant of the avian and mammalian gastrointestinal tracts and can behave commensally or pathogenically. Some enteric diseases caused by type A C. perfringens, including bovine clostridial abomasitis, remain poorly understood.

Macro and micro diversity of Clostridium difficile isolates from diverse sources and geographical locations.

Clostridium difficile has emerged rapidly as the leading cause of antibiotic-associated diarrheal disease, with the temporal and geographical appearance of dominant PCR ribotypes such as 017, 027 and 078. Despite this continued threat, we have a poor understanding of how or why particular variants emerge and the sources of strains that dominate different human populations. We have undertaken a breadth genotyping study using multilocus sequence typing (MLST) analysis of 385 C.

Clostridium perfringens type C and Clostridium difficile co-infection in foals.

Clostridium perfringens type C is one of the most important agents of enteric disease in newborn foals. Clostridium difficile is now recognized as an important cause of enterocolitis in horses of all ages. While infections by C.