Estrella lausannensis, a new star in the Chlamydiales order

Abstract

Originally, the Chlamydiales order was represented by a single family, the Chlamydiaceae, composed of several pathogens, such as Chlamydia trachomatis, Chlamydia pneumoniae, Chlamydia psittaci and Chlamydia abortus. Recently, 6 new families of Chlamydia-related bacteria have been added to the Chlamydiales order. Most of these obligate intracellular bacteria are able to replicate in free-living amoebae. Amoebal co-culture may be used to selectively isolate amoeba-resisting bacteria. This method allowed in a previous work to discover strain CRIB 30, from an environmental water sample. Based on its 16S rRNA gene sequence similarity with Criblamydia sequanensis, strain CRIB 30 was considered as a new member of the Criblamydiaceae family. In the present work, phylogenetic analyses of the genes gyrA, gyrB, rpoA, rpoB, secY, topA and 23S rRNA as well as MALDI-TOF MS confirmed the taxonomic classification of strain CRIB 30. Morphological examination revealed peculiar star-shaped elementary bodies (EBs) similar to those of C. sequanensis. Therefore, this new strain was called "Estrella lausannensis". Finally, E. lausannensis showed a large amoebal host range and a very efficient replication rate in Acanthamoeba species. Furthermore, E. lausannensis is the first member of the Chlamydiales order to grow successfully in the genetically tractable Dictyostelium discoideum, which opens new perspectives in the study of chlamydial biology.

Simkania negevensis, an insight into the biology and clinical importance of a novel member of the Chlamydiales order

“…As an example, crescent bodies and star bodies were reported as infectious EB-like particles of Parachlamydiaceae and Criblamydiaceae, respectively (Lienard et al, 2011b;Thomas et al, 2006). Current knowledge suggests that these observations are largely influenced by the buffer and the fixatives used and therefore do not allow taxonomic discrimination, even if they correspond to some structural differences in the cell wall of the different bacterial families (Pilhofer et al, 2014;.…”

Prevalence and diversity of Chlamydiales and other amoeba-resisting bacteria in domestic drinking water systems

“…The amoebal co-culture using A. castellanii was previously shown to be effective to recover Chlamydiales, including Criblamydiaceae and Parachlamydiaceae [33], [34], but is clearly inadequate to grow all Chlamydiales. Indeed, considering the large biodiversity of the Chlamydiales order highlighted in the present study, only a few members have been isolated by amoebal co-culture [27], [30], [33], [34], [44]. In addition, a restricted amoebal host spectrum has already been shown for several Chlamydiales bacteria [20], [40], [45], [46], which suggests that multiple amoebal strains should ideally be used to recover a higher biodiversity of these strictly intracellular bacteria in culture.…”

Current and Past Strategies for Bacterial Culture in Clinical Microbiology

“…Indeed, since the discovery and description of the new genus Parachlamydia in Acanthamoeba sp. (278), many other bacteria have been isolated from amoebal cultures, including Neochlamydia hartmanella (237), Protochlamydia amoebophila (279), Criblamydia sequanensis (280), Protochlamydia naeglerophila (281), Metachlamydia lacustris (282), Estrella lausanensis (283), and "Candidatus Mesochlamydia elodeae" (240).…”

“…Amoebal coculture led to the discovery of many new microorganisms, particularly new species such as L. drozanskii, L. rowbothami, L. fallonii (250), and L. drancourtii (251). New genera (Chlamydia-and Parachlamydia-related microorganisms) (282,283) and new phyla (Babela massiliensis) (Pagnier et al, unpublished) or life domains (all amoeba-associated giant viruses) have also been recovered by amoebal coculture. The example of the isolation of Babela massiliensis (CSUR P554; GenBank accession number GQ495224 for 16S rRNA) is a good illustration of the increasing importance of microbial culture (Pagnier et al, unpublished).…”