Legionella tunisiensis sp. nov. and Legionella massiliensis sp. nov., isolated from environmental water samples

Campocasso, Angélique; Boughalmi, Mondher; Fournous, Ghislain; Raoult, Didier; Scola, Bernard La

doi:10.1099/ijs.0.037853-0

Cited by 30 publications

(17 citation statements)

References 13 publications

(14 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Taking into account that our experimental analysis of the L. longbeachae predicted effectors resulted in 70% prediction accuracy, we estimate that at least 50 species-specific effectors are present in each of the Legionella species. Because 58 different Legionella species are currently known (44,45), an enormous number of bacterial effectors that subvert host cell processes are expected to be found in the Legionella genus.…”

Section: Discussionmentioning

confidence: 99%

Computational modeling and experimental validation of the Legionella and Coxiella virulence-related type-IVB secretion signal

Lifshitz¹,

Burstein

Peeri

et al. 2013

Proc. Natl. Acad. Sci. U.S.A.

168

189

View full text Add to dashboard Cite

Legionella and Coxiella are intracellular pathogens that use the virulence-related Icm/Dot type-IVB secretion system to translocate effector proteins into host cells during infection. These effectors were previously shown to contain a C-terminal secretion signal required for their translocation. In this research, we implemented a hidden semi-Markov model to characterize the amino acid composition of the signal, thus providing a comprehensive computational model for the secretion signal. This model accounts for dependencies among sites and captures spatial variation in amino acid composition along the secretion signal. To validate our model, we predicted and synthetically constructed an optimal secretion signal whose sequence is different from that of any known effector. We show that this signal efficiently translocates into host cells in an Icm/Dot-dependent manner. Additionally, we predicted in silico and experimentally examined the effects of mutations in the secretion signal, which provided innovative insights into its characteristics. Some effectors were found to lack a strong secretion signal according to our model. We demonstrated that these effectors were highly dependent on the IcmS-IcmW chaperons for their translocation, unlike effectors that harbor a strong secretion signal. Furthermore, our model is innovative because it enables searching ORFs for secretion signals on a genomic scale, which led to the identification and experimental validation of 20 effectors from Legionella pneumophila, Legionella longbeachae, and Coxiella burnetii. Our combined computational and experimental methodology is general and can be applied to the identification of a wide spectrum of protein features that lack sequence conservation but have similar amino acid characteristics.pathogenomics | type-IV secretion | translocated substrates | Legionnaire disease | Q-fever

show abstract

Section: Discussionmentioning

confidence: 99%

Computational modeling and experimental validation of the Legionella and Coxiella virulence-related type-IVB secretion signal

Lifshitz¹,

Burstein

Peeri

et al. 2013

Proc. Natl. Acad. Sci. U.S.A.

168

189

View full text Add to dashboard Cite

show abstract

“…This strain was thus considered L. donaldsonii-like and potentially novel. Notably, L. tunisiensis is a newly described species in 2012 that was isolated from environmental water with hitherto unknown clinical significance (15). The 16S sequences of strains MDA4726 and MDA6655 showed considerable difference, matching at 98.7% (1,460/1,479).…”

Section: General Clinical Featuresmentioning

confidence: 99%

Microbiological and Clinical Studies of Legionellosis in 33 Patients with Cancer

et al. 2015

View full text Add to dashboard Cite

“…Currently, we have cultured 41 different T. whipplei strains from diverse tissues and fluid (310,312,374,375,390,391), playing a key role in the understanding of the clinical manifestations caused by this bacterium (194). Coculture with amoebae, which was performed in our laboratory, has allowed us to identify 139 different bacterial species from both clinical and environmental samples, including 10 new bacterial species (224,235,239,251,261,(392)(393)(394)(395)(396). In our laboratory, the great qualities of several "cultivators," technicians, or researchers were identified and recognized in the names of bacterial species to honor these qualities (i.e., Rickettsia raoultii, Legionella drancourtii, Mycobacterium barrassiae, Afipia birgiae, Bosea vestrisii, and Bosea eneae, etc.…”

Section: Resultsmentioning

confidence: 99%

Current and Past Strategies for Bacterial Culture in Clinical Microbiology

et al. 2015

Self Cite

View full text Add to dashboard Cite

SUMMARY A pure bacterial culture remains essential for the study of its virulence, its antibiotic susceptibility, and its genome sequence in order to facilitate the understanding and treatment of caused diseases. The first culture conditions empirically varied incubation time, nutrients, atmosphere, and temperature; culture was then gradually abandoned in favor of molecular methods. The rebirth of culture in clinical microbiology was prompted by microbiologists specializing in intracellular bacteria. The shell vial procedure allowed the culture of new species of Rickettsia . The design of axenic media for growing fastidious bacteria such as Tropheryma whipplei and Coxiella burnetii and the ability of amoebal coculture to discover new bacteria constituted major advances. Strong efforts associating optimized culture media, detection methods, and a microaerophilic atmosphere allowed a dramatic decrease of the time of Mycobacterium tuberculosis culture. The use of a new versatile medium allowed an extension of the repertoire of archaea. Finally, to optimize the culture of anaerobes in routine bacteriology laboratories, the addition of antioxidants in culture media under an aerobic atmosphere allowed the growth of strictly anaerobic species. Nevertheless, among usual bacterial pathogens, the development of axenic media for the culture of Treponema pallidum or Mycobacterium leprae remains an important challenge that the patience and innovations of cultivators will enable them to overcome.

show abstract

Legionella tunisiensis sp. nov. and Legionella massiliensis sp. nov., isolated from environmental water samples

Cited by 30 publications

References 13 publications

Computational modeling and experimental validation of the Legionella and Coxiella virulence-related type-IVB secretion signal

Computational modeling and experimental validation of the Legionella and Coxiella virulence-related type-IVB secretion signal

Microbiological and Clinical Studies of Legionellosis in 33 Patients with Cancer

Current and Past Strategies for Bacterial Culture in Clinical Microbiology

Contact Info

Product

Resources

About