Legionella pneumophila IrsA, a novel, iron-regulated exoprotein that facilitates growth in low-iron conditions and modulates biofilm formation DOI Creative Commons
Alberto E. Lopez, Joshua Mayoral,

Huaixin Zheng

et al.

Microbiology Spectrum, Journal Year: 2024, Volume and Issue: unknown

Published: Nov. 29, 2024

ABSTRACT To discover new factors that are involved in iron acquisition by Legionella pneumophila , we used RNA-Seq to identify the genes most highly induced when virulent strain 130b is cultured a low-iron chemically defined medium. Among other things, this revealed 14915 heretofore uncharacterized gene predicted be transcriptionally regulated Fur and encode novel, ~15 kDa protein. was present all L. strains examined had homologs subset of species. Compatible with it containing classic signal sequence, protein detected bacterial culture supernatants manner dependent upon type II secretion system. Thus, designated as IrsA for ir on- r egulated, s ecreted A . Based on mutant analysis, irsA not required optimal growth media. However, after discovering commonly laboratory-derived Lp02 has much greater requirement iron, uncovered growth-enhancing role examining an lacked both Fe 2+ -transporter FeoB. The 130b, but its complemented derivative, did, however, display increased biofilm formation plastic agar surfaces, compatible this, hyper-aggregated. iron-regulated exoprotein modulates and, under some circumstances, promotes conditions. For study, determined deposited database complete fully assembled genome sequence 130b. IMPORTANCE bacterium principal cause Legionnaires’ disease, potentially fatal form pneumonia increasing incidence. exists many natural human-made water systems can transmitted humans through inhalation contaminated droplets. flourishes within habitats spreading planktonically, assembling into biofilms, growing larger host cells. Iron key determinant persistence during infection. We previously demonstrated assimilates secreting non-protein chelator (siderophore) importing membrane transporters. In secreted iron-regulated, ’s media, impacts formation. also identified uncharacterized, IrsA-related proteins important human animal pathogens. our results have implications understanding assimilation, formation, pathogenesis.

Language: Английский

The dominant lineage of an emerging pathogen harbours contact-dependent inhibition systems DOI Creative Commons
Cristian V. Crisan, Joanna B. Goldberg

Microbial Genomics, Journal Year: 2025, Volume and Issue: 11(1)

Published: Jan. 24, 2025

Bacteria from the Stenotrophomonas maltophilia complex (Smc) are important multidrug-resistant pathogens that cause a broad range of infections. Smc is genomically diverse and has been classified into 23 lineages. Lineage Sm6 most common among sequenced strains, but it unclear why this lineage evolved to be dominant. Antagonistic interactions can significantly affect evolution bacterial populations. These may mediated by secreted contact-dependent proteins, which allow inhibitor cells intoxicate adjacent target bacteria. Contact-dependent inhibition (CDI) requires three proteins: CdiA, CdiB CdiI. CdiA large, filamentous protein exported surface through pore-like CdiB. The C-terminal domain (CdiA-CT) toxic when delivered same species or genus. CdiI immunity proteins neutralize toxicity cognate CdiA-CT toxins. We found all complete genomes harbour at least one CDI locus. By contrast, less than quarter strains other lineages have genes. domains predicted functions. Most non-cognate cdiI genes provide protection against foreign toxins strains. Finally, we demonstrated an toxin antibacterial properties neutralized its

Language: Английский

Citations

0
The type II secretion system as an underappreciated and understudied mediator of interbacterial antagonism DOI
Nicholas P. Cianciotto

Infection and Immunity, Journal Year: 2024, Volume and Issue: 92(8)

Published: Aug. 13, 2024

ABSTRACT Interbacterial antagonism involves all major phyla, occurs across the full range of ecological niches, and has great significance for environment, clinical arena, agricultural industrial sectors. Though earliest insight into interbacterial traces back to discovery antibiotics, a paradigm shift happened when it was learned that protein secretion systems (e.g., types VI IV systems) deliver toxic “effectors” against competitors. However, link between Gram-negative type II system (T2SS), which exists in many pathogens environmental species, is not evident prior reviews on bacterial competition or T2SS function. A current examination literature revealed four examples one its known substrates having bactericidal activity Gram-positive target another Gram-negative. When further studied, effectors proved be peptidases peptidoglycan competitor. There are also reports various bacteriolytic enzymes occurring culture supernatants some other these activities suggested. Thus, can mediator antagonism, possible T2SSs have antibacterial outputs. Yet, at present, remains relatively understudied role competition. Arguably, there need analyze broader species their antagonism. Such investigation offers, among things, pathway toward developing new antimicrobials treating disease.

Language: Английский

Citations

2
Legionella pneumophila IrsA, a novel, iron-regulated exoprotein that facilitates growth in low-iron conditions and modulates biofilm formation DOI Creative Commons
Alberto E. Lopez, Joshua Mayoral,

Huaixin Zheng

et al.

Microbiology Spectrum, Journal Year: 2024, Volume and Issue: unknown

Published: Nov. 29, 2024

ABSTRACT To discover new factors that are involved in iron acquisition by Legionella pneumophila , we used RNA-Seq to identify the genes most highly induced when virulent strain 130b is cultured a low-iron chemically defined medium. Among other things, this revealed 14915 heretofore uncharacterized gene predicted be transcriptionally regulated Fur and encode novel, ~15 kDa protein. was present all L. strains examined had homologs subset of species. Compatible with it containing classic signal sequence, protein detected bacterial culture supernatants manner dependent upon type II secretion system. Thus, designated as IrsA for ir on- r egulated, s ecreted A . Based on mutant analysis, irsA not required optimal growth media. However, after discovering commonly laboratory-derived Lp02 has much greater requirement iron, uncovered growth-enhancing role examining an lacked both Fe 2+ -transporter FeoB. The 130b, but its complemented derivative, did, however, display increased biofilm formation plastic agar surfaces, compatible this, hyper-aggregated. iron-regulated exoprotein modulates and, under some circumstances, promotes conditions. For study, determined deposited database complete fully assembled genome sequence 130b. IMPORTANCE bacterium principal cause Legionnaires’ disease, potentially fatal form pneumonia increasing incidence. exists many natural human-made water systems can transmitted humans through inhalation contaminated droplets. flourishes within habitats spreading planktonically, assembling into biofilms, growing larger host cells. Iron key determinant persistence during infection. We previously demonstrated assimilates secreting non-protein chelator (siderophore) importing membrane transporters. In secreted iron-regulated, ’s media, impacts formation. also identified uncharacterized, IrsA-related proteins important human animal pathogens. our results have implications understanding assimilation, formation, pathogenesis.

Language: Английский

Citations

0