The gut microbiota is associated with psychiatric symptom severity and treatment outcome among individuals with serious mental illness.

BACKGROUND: Emerging evidence implicates the gut microbiota in central nervous system functioning via its effects on inflammation, the hypothalamic-pituitary axis, and/or neurotransmission. Our understanding of the cellular underpinnings of the brain-gut relationship is based almost exclusively on animal models with some small-scale human studies. This study examined the relationship between the gut microbiota and psychiatric symptom severity and treatment response among inpatients with serious mental illness. METHOD: We collected data from adult inpatients (N = 111). Measures of diagnoses, suicide severity, trauma, depression, and anxiety were collected shortly after admission, while self-collected fecal swabs were collected early in the course of hospitalization and processed using 16S rRNA gene sequencing and whole genome shotgun sequencing methods. RESULTS: Results indicate that depression and anxiety severity shortly after admission were negatively associated with bacterial richness and alpha diversity. Additional analyses revealed a number of bacterial taxa associated with depression and anxiety severity. Gut microbiota richness and alpha diversity early in the course of hospitalization was a significant predictor of depression remission at discharge. CONCLUSIONS: This study is among the first to demonstrate a gut microbiota relationship with symptom severity among psychiatric inpatients as well as a relationship to remission of depression post-treatment. These findings are consistent with animal models and limited human studies as well as with the broader literature implicating inflammation in the pathophysiology of depression. These findings offer the foundation for further studies of novel therapeutic approaches to the treatment, prevention of, or recurrence of serious mental illness.

Impact of Oral Fidaxomicin Administration on the Intestinal Microbiota and Susceptibility to Clostridium difficile Colonization in Mice.

Clostridium difficile infection (CDI), a common cause of hospital-acquired infections, typically occurs after disruption of the normal gut microbiome by broad-spectrum antibiotics. Fidaxomicin is a narrow-spectrum antibiotic that demonstrates a reduced impact on the normal gut microbiota and is approved for the treatment of CDI. To further explore the benefits of this property, we used a murine model to examine the effects of fidaxomicin versus vancomycin on gut microbiota and susceptibility to C. difficile colonization while tracking microbiota recovery over time. Mice were exposed to fidaxomicin or vancomycin by oral gavage for 3 days and subsequently challenged with C. difficile spores at predetermined time points up to 21 days postexposure to antibiotics. Fecal samples were subsequently collected for analysis. Twenty-four hours postchallenge, mice were euthanized and the colon contents harvested. The microbiota was characterized using 16S rRNA gene sequencing. All fidaxomicin-exposed mice (except for one at day 8) were resistant to C. difficile colonization. However, 9 of 15 vancomycin-exposed mice were susceptible to C. difficile colonization until day 12. All vancomycin-exposed mice recovered colonization resistance by day 16. Bacterial diversity was similar prior to antibiotic exposure in both arms and decreased substantially after exposure. A shift in taxonomic structure and composition occurred after both exposures; however, the shift was greater in vancomycin-exposed than in fidaxomicin-exposed mice. In summary, compared with vancomycin, fidaxomicin exposure had less impact on microbiota composition, promoted faster microbial recovery, and had less impact on the loss of C. difficile colonization resistance.

Isolation and concentration of bacteria from blood using microfluidic membraneless dialysis and dielectrophoresis.

A microfluidic system that combines membraneless microfluidic dialysis and dielectrophoresis to achieve label-free isolation and concentration of bacteria from whole blood is presented. Target bacteria and undesired blood cells are discriminated on the basis of their differential susceptibility to permeabilizing agents that alter the dielectrophoretic behavior of blood cells but not bacteria. The combined membraneless microdialysis and dielectrophoresis system isolated 79 ± 3% of Escherichia coli and 78 ± 2% of Staphylococcus aureus spiked into whole blood at a processing rate of 0.6 mL h-1. Collection efficiency was independent of the number of target bacteria up to 105 cells. Quantitative PCR analysis revealed that bacterial 16S rDNA levels were enriched more than 307-fold over human DNA in the fraction recovered from the isolation system compared with the original specimen. These data demonstrate feasibility for an instrument to accelerate the detection and analysis of bacteria in blood by first isolating and concentrating them in a microchamber.

The relationship between nasopharyngeal CCL5 and microbiota on disease severity among infants with bronchiolitis.

Emerging evidence suggests that the airway microbiota plays an important role in viral bronchiolitis pathobiology. However, little is known about the combined role of airway microbiota and CCL5 in infants with bronchiolitis. In this multicenter prospective cohort study of 1005 infants (age <1 year) hospitalized for bronchiolitis during 2011-2014, we observed statistically significant interactions between nasopharyngeal airway CCL5 levels and microbiota profiles with regard to the risk of both intensive care use (Pinteraction =.02) and hospital length-of-stay ≥3 days (Pinteraction =.03). Among infants with lower CCL5 levels, the Haemophilus-dominant microbiota profile was associated with a higher risk of intensive care use (OR, 3.20; 95%CI, 1.18-8.68; P=.02) and hospital length-of-stay ≥3 days (OR, 4.14; 95%CI, 2.08-8.24; P<.001) compared to the Moraxella-dominant profile. Conversely, among those with higher CCL5 levels, there were no significant associations between the microbiota profiles and these severity outcomes (all P≥.10).

Randomised clinical trial: faecal microbiota transplantation for recurrent Clostridum difficile infection - fresh, or frozen, or lyophilised microbiota from a small pool of healthy donors delivered by colonoscopy.

BACKGROUND: Faecal microbiota transplantation (FMT) has become routine in managing recurrent C. difficile infection (CDI) refractory to antibiotics. AIM: To compare clinical response and improvements in colonic microbiota diversity in subjects with recurrent CDI using different donor product. METHODS: Seventy-two subjects with ≥3 bouts of CDI were randomised in a double-blind study to receive fresh, frozen or lyophilised FMT product via colonoscopy from 50 g of stool per treatment from eight healthy donors. Recipients provided stools pre- and 7, 14 and 30 days post-FMT for C. difficile toxin and, in a subset, microbiome composition by 16S rRNA gene profiling. RESULTS: Overall resolution of CDI was 87% during 2 months of follow-up after FMT. Stool samples before FMT had significantly decreased bacterial diversity with a high proportion of Proteobacteria compared to donors. Cure rates were highest for the group receiving fresh product seen in 25/25 (100%), lowest for the lyophilised product 16/23 (78%; P = 0.022 vs. fresh and 0.255 vs. frozen) and intermediate for frozen product 20/24 (P = 0.233 vs. fresh). Microbial diversity was reconstituted by day 7 in the subjects receiving fresh or frozen product. Improvement in diversity was seen by day 7 in those randomised to lyophilised material with reconstitution by 30 days. CONCLUSIONS: Comparative efficacy in faecal microbiota transplantation was observed in subjects receiving fresh or frozen faecal product from the same donors. The lyophilised product had a slightly lowered efficacy compared with fresh product, but it resembled other treatments in microbial restoration 1 month after faecal microbiota transplantation.

Complete Genome Sequence of Turicibacter sp. Strain H121, Isolated from the Feces of a Contaminated Germ-Free Mouse.

Turicibacterbacteria are commonly detected in the gastrointestinal tracts and feces of humans and animals, but their phylogeny, ecological role, and pathogenic potential remain unclear. We present here the first complete genome sequence ofTuricibactersp. strain H121, which was isolated from the feces of a mouse line contaminated following germ-free derivation.

High-Quality Draft Genome Sequence of Francisella tularensis subsp. holarctica Strain OR96-0246.

The bacterial pathogen Francisella tularensis was recently renewed as a tier-one select agent. F. tularensis subsp. tularensis (type A) and holarctica (type B) are of clinical relevance. Here, we report the complete genome of a virulent F. tularensis type B strain and describe its usefulness in comparative genomics.

Presence of viral proteins in drinkable water--sufficient condition to consider water a vector of viral transmission?

In order to determine the role of water as a possible vector for transmission of the most prevalent enteric viruses affecting infantile populations, 226 water samples were collected from Facatativa's (Colombian municipality located 30km away from Bogotá) water works in the years 2000, 2002, and 2005. The samples were clarified and virus was concentrated by filtering and ultrafiltering techniques. The presence of viral protein (VP) was assessed by enzyme immunoassay method (EIA) and viral RNA presence was detected by reverse trascriptase and polymerase chain reaction (RT-PCR). Using these techniques, one sample positive for Astrovirus (HAstV) was found in a sample collected from the river that supplies the aqueduct, two samples positive for Norovirus (NV) from fresh treated potable water and 13 samples positive for Rotavirus (RV), some in water from the plant during treatment and others from treated fresh water. RT-PCR inhibitors were also found in water samples obtained from the plant and in the fresh treated water. No inhibitors were found in the river water. VP, but no nucleic acid, was detected in the water samples at different stages of treatment, thus suggesting that the virus might have been complete and infectious at some stage prior to water purification.