Developmentally-regulated proteolysis by MdfA and ClpCP mediates metabolic differentiation during sporulation.

sporulation entails a dramatic transformation of the two cells required to assemble a dormant spore, with the larger mother cell engulfing the smaller forespore to produce the cell-within-a-cell structure that is a hallmark of endospore formation. Sporulation also entails metabolic differentiation, whereby key metabolic enzymes are depleted from the forespore but maintained in the mother cell. This reduces the metabolic potential of the forespore, which becomes dependent on mother-cell metabolism and the SpoIIQ-SpoIIIA channel to obtain metabolic building blocks necessary for development.

Empowering STEM students: A university-wide mentorship program fostering retention and belonging.

In the face of a challenging climate STEM (Science, Technology, Engineering and Mathematics) higher education that is resistant to Diversity, Equity, and Inclusion efforts aimed to increase and retain students from historically excluded groups (HEGs), there is a critical need for a support structure to ensure students from HEGs continue to be recruited retained. The Biology Undergraduate and Master's Mentorship Program (BUMMP) embodies this commitment to fostering scientific identity, efficacy, and a sense of belonging for first-generation and historically underserved undergraduate and master's students at UC San Diego. The mission of BUMMP is to cultivate a sense of belonging, instill confidence, and nurture a strong scientific identity amongst all its participants.

A population-level strain genotyping method to study pathogen strain dynamics in human infections.

A hallmark of chronic bacterial infections is the long-term persistence of 1 or more pathogen species at the compromised site. Repeated detection of the same bacterial species can suggest that a single strain or lineage is continually present. However, infection with multiple strains of a given species, strain acquisition and loss, and changes in strain relative abundance can occur.

Functional reconstitution of a bacterial CO concentrating mechanism in .

Many photosynthetic organisms employ a CO concentrating mechanism (CCM) to increase the rate of CO fixation via the Calvin cycle. CCMs catalyze ≈50% of global photosynthesis, yet it remains unclear which genes and proteins are required to produce this complex adaptation. We describe the construction of a functional CCM in a non-native host, achieved by expressing genes from an autotrophic bacterium in an strain engineered to depend on rubisco carboxylation for growth.

Maintenance tobramycin primarily affects untargeted bacteria in the CF sputum microbiome.

Rationale: The most common antibiotic used to treat people with cystic fibrosis (PWCF) is inhaled tobramycin, administered as maintenance therapy for chronic lung infections. While the effects of inhaled tobramycin on abundance and lung function diminish with continued therapy, this maintenance treatment is known to improve long-term outcomes, underscoring how little is known about why antibiotics work in CF infections, what their effects are on complex CF sputum microbiomes and how to improve these treatments.

Objectives: To rigorously define the effect of maintenance tobramycin on CF sputum microbiome characteristics.

Cell free DNA from respiratory pathogens is detectable in the blood plasma of Cystic Fibrosis patients.

Diagnostically informative microbial cell-free DNA (cfDNA) can be detected from blood plasma during fulminant infections such as sepsis. However, the potential for DNA from airway pathogens to enter the circulation of cystic fibrosis (CF) patients during chronic infective states has not yet been evaluated. We assessed whether patient blood contained measurable quantities of cfDNA from CF respiratory microorganisms by sequencing plasma from 21 individuals with CF recruited from outpatient clinics and 12 healthy controls.

Bacterial fitness in chronic wounds appears to be mediated by the capacity for high-density growth, not virulence or biofilm functions.

While much is known about acute infection pathogenesis, the understanding of chronic infections has lagged. Here we sought to identify the genes and functions that mediate fitness of the pathogen Pseudomonas aeruginosa in chronic wound infections, and to better understand the selective environment in wounds. We found that clinical isolates from chronic human wounds were frequently defective in virulence functions and biofilm formation, and that many virulence and biofilm formation genes were not required for bacterial fitness in experimental mouse wounds.

Gallium disrupts bacterial iron metabolism and has therapeutic effects in mice and humans with lung infections.

The lack of new antibiotics is among the most critical challenges facing medicine. The problem is particularly acute for Gram-negative bacteria. An unconventional antibiotic strategy is to target bacterial nutrition and metabolism.

Evolved Aztreonam Resistance Is Multifactorial and Can Produce Hypervirulence in .

While much attention has been focused on acquired antibiotic resistance genes, chromosomal mutations may be most important in chronic infections where isolated, persistently infecting lineages experience repeated antibiotic exposure. Here, we used experimental evolution and whole-genome sequencing to investigate chromosomally encoded mutations causing aztreonam resistance in and characterized the secondary consequences of resistance development. We identified 19 recurrently mutated genes associated with aztreonam resistance.