Natural Competence for DNA Transformation by
            <i>Legionella pneumophila</i>
            and Its Association with Expression of Type IV Pili

Stone, Bronte A.; Kwaik, Yousef Abu

doi:10.1128/jb.181.5.1395-1402.1999

Cited by 180 publications

(74 citation statements)

References 55 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The origin of the Ivh conjugation system and its role in the development of pathogenicity remain unclear. Further, it has been shown that L. pneumophila is naturally competent for DNA transformation (Stone and Abu Kwaik, 1999). The presence of two conjugation systems and the ability of L. pneumophila to take up DNA through natural competency suggest that genetic exchange through these systems may have played a role in the pathogenic evolution of this bacterium.…”

Section: Discussionmentioning

confidence: 99%

From protozoa to mammalian cells: a new paradigm in the life cycle of intracellular bacterial pathogens

Harb¹,

Gao²,

Kwaik³

2000

Environmental Microbiology

Self Cite

200

166

View full text Add to dashboard Cite

It is becoming apparent that several intracellular bacterial pathogens of humans can also survive within protozoa. This interaction with protozoa may protect these pathogens from harsh conditions in the extracellular environment and enhance their infectivity in mammals. This relationship has been clearly established in the case of the interaction between Legionella pneumophila and its protozoan hosts. In addition, the adaptation of bacterial pathogens to the intracellular life within the primitive eukaryotic protozoa may have provided them with the means to infect the more evolved mammalian cells. This is evident from the existence of several similarities, at both the phenotypic and the molecular levels, between the infection of mammalian and protozoan cells by L. pneumophila. Thus, protozoa appear to play a central role in the transition of bacteria from the environment to mammals. In essence, protozoa may be viewed as a ‘biological gym’, within which intracellular bacterial pathogens train for their encounters with the more evolved mammalian cells. Thus, intracellular bacterial pathogens have benefited from the structural and biochemical conservation of cellular processes in eukaryotes. The interaction of intracellular bacterial pathogens and protozoa highlights this conservation and may constitute a simplified model for the study of these pathogens and the evolution of cellular processes in eukaryotes. Furthermore, in addition to being environmental reservoirs for known intracellular pathogens of humans and animals, protozoa may be sources of emerging pathogenic bacteria. It is thus critical to re‐examine the relationship between bacteria and protozoa to further our understanding of current human bacterial pathogenesis and, possibly, to predict the appearance of emerging pathogens.

show abstract

Section: Discussionmentioning

confidence: 99%

From protozoa to mammalian cells: a new paradigm in the life cycle of intracellular bacterial pathogens

Harb¹,

Gao²,

Kwaik³

2000

Environmental Microbiology

Self Cite

200

166

View full text Add to dashboard Cite

show abstract

“…Thus, it will be interesting to see whether the Legionella autoinducer-1 (LAI-1; Spirig et al, 2008) is also required for natural competence and transformation in this bacterium. It had long been appreciated that L. pneumophila is naturally transformable (Stone & Kwaik, 1999), and recent studies have provided evidence that competence might fulfil a similar function in this organism as in S. pneumoniae, replacing the absent SOS response (Charpentier et al, 2011).…”

Section: The Induction Of Competence In V Cholerae Compared With Thementioning

confidence: 99%

Cues and regulatory pathways involved in natural competence and transformation in pathogenic and environmental Gram-negative bacteria

Seitz¹,

Blokesch²

2013

FEMS Microbiol Rev

196

201

View full text Add to dashboard Cite

Bacterial genomics is flourishing, as whole-genome sequencing has become affordable, readily available and rapid. As a result, it has become clear how frequently horizontal gene transfer (HGT) occurs in bacteria. The potential implications are highly significant because HGT contributes to several processes, including the spread of antibiotic-resistance cassettes, the distribution of toxin-encoding phages and the transfer of pathogenicity islands. Three modes of HGT are recognized in bacteria: conjugation, transduction and natural transformation. In contrast to the first two mechanisms, natural competence for transformation does not rely on mobile genetic elements but is driven solely by a developmental programme in the acceptor bacterium. Once the bacterium becomes competent, it is able to take up DNA from the environment and to incorporate the newly acquired DNA into its own chromosome. The initiation and duration of competence differ significantly among bacteria. In this review, we outline the latest data on representative naturally transformable Gram-negative bacteria and how their competence windows differ. We also summarize how environmental cues contribute to the initiation of competence in a subset of naturally transformable Gram-negative bacteria and how the complexity of the niche might dictate the fine-tuning of the competence window.

show abstract

“…Many of the lid transposon insertions were backcrossed into fresh backgrounds by a modified natural transformation procedure to test for linkage of the mutation to the Lid phenotype (Stone and Kwaik, 1999). Recipient strains were patched for 48 h at 37∞C, and a thin layer of bacteria was transferred to a fresh plate, incubating further for 24 h at 30∞C (J. P. Vogel, unpubl.…”

Section: Backcrosses Of Transposon Insertions By Natural Transformationmentioning

confidence: 99%

“…Transformants were then selected on CYE plates containing thymidine and kanamycin. As the only origin of replication on the DNA was from R6K, which cannot replicate in L. pneumophila, and there is apparent cleavage of the circular plasmid into a linear form after natural transformation (Stone and Kwaik, 1999), Kan R colonies could only arise by double crossover. Transformation ratios in each strain tested were obtained by dividing the number of kanamycin resistant bacteria by the total number of bacteria found in each patch, as determined by plating non-selectively on CYE-thymidine plates.…”

Section: Backcrosses Of Transposon Insertions By Natural Transformationmentioning

confidence: 99%

The Legionella pneumophila LidA protein: a translocated substrate of the Dot/Icm system associated with maintenance of bacterial integrity

Conover¹,

Derré²,

Vogel

et al. 2003

Molecular Microbiology

244

307

View full text Add to dashboard Cite

SummaryLegionella pneumophila establishes a replication vacuole within phagocytes that requires the bacterial Dot/ Icm apparatus for its formation. This apparatus is predicted to translocate effectors into host cells. We hypothesized that some translocated proteins also function to maintain the integrity of the Dot/Icm translocator. Mutations that destroy this function are predicted to result in a Dot/Icm complex that poisons the bacterium, resulting in reduced viability. To identify such mutants, strains were isolated (called lid -) that showed reduced viability on bacteriological medium in the presence of an intact Dot/Icm apparatus, but which had high viability in the absence of the translocator. Several such mutants were analysed in detail to identify candidate strains that may have lost the ability to synthesize a translocated substrate of Dot/ Icm. Two such strains had mutations in the lidA gene. The LidA protein exhibits properties expected for a translocated substrate of Dot/Icm that is important for maintenance of bacterial cell integrity: it associates with the phagosomal surface, promotes replication vacuole formation, and is important for both efficient intracellular growth and high viability on bacteriological media after introduction of a plasmid that allows high level expression of the dotA gene.

show abstract

Natural Competence for DNA Transformation by Legionella pneumophila and Its Association with Expression of Type IV Pili

Cited by 180 publications

References 55 publications

From protozoa to mammalian cells: a new paradigm in the life cycle of intracellular bacterial pathogens

From protozoa to mammalian cells: a new paradigm in the life cycle of intracellular bacterial pathogens

Cues and regulatory pathways involved in natural competence and transformation in pathogenic and environmental Gram-negative bacteria

The Legionella pneumophila LidA protein: a translocated substrate of the Dot/Icm system associated with maintenance of bacterial integrity

Contact Info

Product

Resources

About