Independent evolution of shape and motility allows evolutionary flexibility in Firmicutes bacteria

Functional morphological adaptation is an implicit assumption across many ecological studies. However, despite a few pioneering attempts to link bacterial form and function, functional morphology is largely unstudied in prokaryotes. One intriguing candidate for analysis is bacterial shape, as multiple lines of theory indicate that cell shape and motility should be strongly correlated. Here we present a large-scale use of modern phylogenetic comparative methods to explore this relationship across 325 species of the phylum Firmicutes. In contrast to clear predictions from theory, we show that cell shape and motility are not coupled, and that transitions to and from flagellar motility are common and strongly associated with lifestyle (free-living or host-associated). We find no association between shape and lifestyle, and contrary to recent evidence, no indication that shape is associated with pathogenicity. Our results suggest that the independent evolution of shape and motility in this group might allow a greater evolutionary flexibility

The cystic fibrosis microbiome in an ecological perspective and its impact in antibiotic therapy

The recent focus on the cystic fibrosis (CF) complex microbiome has led to the recognition that the microbes can interact between them and with the host immune system, affecting the disease progression and treatment routes. Although the main focus remains on the interactions between traditional pathogens, growing evidence supports the contribution and the role of emergent species. Understanding the mechanisms and the biological effects involved in polymicrobial interactions may be the key to improve effective therapies and also to define new strategies for disease control. This review focuses on the interactions between microbe-microbe and host-microbe, from an ecological point of view, discussing their impact on CF disease progression. There are increasing indications that these interactions impact the success of antimicrobial therapy. Consequently, a new approach where therapy is personalized to patients by taking into account their individual CF microbiome is suggested.Portuguese Foundation for Science and Technology (FCT), the strategic funding of UID/BIO/04469/2013-CEB and UID/EQU/00511/2013-LEPABE units. This study was also supported by FCT and the European Community fund FEDER, through Program COMPETE, under the scope of the Projects “DNA mimics” PIC/IC/82815/2007, RECI/BBB-EBI/0179/2012 (FCOMP-01-0124-FEDER-027462), “BioHealth—Biotechnology and Bioengineering approaches to improve health quality”, Ref. NORTE-07-0124-FEDER-000027 and NORTE-07-0124-FEDER-000025—RL2_ Environment and Health, co-funded by the Programa Operacional Regional do Norte (ON.2 – O Novo Norte), QREN, FEDER. The authors also acknowledge the grant of Susana P. Lopes (SFRH/BPD/95616/2013) and of the COST-Action TD1004: Theragnostics for imaging and therapy

Lung defense through interleukin-8 carries a cost of chronic lung remodeling and impaired function

RATIONALE: IL-8 dependent inflammation is a hallmark of host lung innate immunity to bacterial pathogens, yet in many human lung diseases including COPD, bronchiectasis, and pulmonary fibrosis, there are progressive, irreversible pathologic, changes associated with elevated levels of IL-8 in the lung. OBJECTIVES: To better understand the duality of IL-8 dependent host immunity to bacterial infection and lung pathology, we targeted human IL-8 to express transgenically in murine bronchial epithelium, investigating the impact of over-expression on lung bacterial clearance, host immunity, lung pathology and function. MEASUREMENTS AND MAIN RESULTS: Persistent IL-8 expression in bronchial epithelium resulted in neutrophilia, neutrophil maturation, activation and chemtoaxis. There was enhanced protection from challenge with Pseudomonas aeruginosa and significant changes in baseline expression of innate and adaptive immunity transcripts for Ccl5, Tlr6, IL2 and Tlr1. There was increased expression of Tbet and Foxp3 in response to the Pseudomonas antigen, OprF, indicating a regulatory T cell phenotype. However, this enhanced bacterial immunity comes at the high price of progressive lung remodelling, with increased inflammation, mucus hyper-secretion, and fibrosis. There is increased expression of Ccl3 and reduced expressioh of Claudin 18 and F11r, with damage to epithelial organization leading to leaky tight junctions, all resulting in impaired lung function with reduced compliance, increased resistance and bronchial hyperreactivity measured by whole body plethysmography. CONCLUSIONS: IL-8 over-expression in the bronchial epithelium benefits lung immunity to bacterial infection, but specifically drives lung damage through persistent inflammation, lung remodelling and damaged tight junctions, leading to impaired lung function

Quantitative genetics of preference and performance on chickpeas in the noctuid moth, Helicoverpa armigera

If a novel, resistant host plant genotype arises in the environment, insect populations utilising that host must be able to overcome that resistance in order that they can maintain their ability to feed on that host. The ability to evolve resistance to host-plant defences depends upon additive genetic variation in larval performance and adult host-choice preference. To investigate the potential of a generalist herbivore to respond to a novel resistant host we estimated the heritability of larval performance in the noctuid moth, Helicoverpa armigera, on a resistant and a susceptible variety of the chickpea, Cicer arietinum, at two different life-stages. Heritability estimates were higher for neonates than for third-instar larvae suggesting that their ability to establish on plants could be key to the evolution of resistance in this species, however further information regarding the nature of selection in the field would be required to confirm this prediction. There was no genetic correlation between larval performance and oviposition preference, indicating that female moths do not choose the most suitable plant for their offspring. We also found significant genotype by environment interactions for neonates (but not third-instar larvae), suggesting that the larval response to different plant genotypes is stage-specific in this species

NAIP/NLRC4 inflammasome activation in MRP8+ cells is sufficient to cause systemic inflammatory disease

Inflammasomes are protein complexes induced by pathogens for the secretion of pro-inflammatory cytokines IL-1β and IL-18 in immune cells. Here the authors show, using a new mouse model, that aberrant NLRC4 and ASC-dependent inflammasome activation in neutrophils contributes to systemic inflammation