Identification of a Cytopathogenic Toxin from <i>Sneathia amnii</i>

Gentile, Gabriella; Rupert, Amy Sanford; Carrasco, Lizette; Garcia, Erin M.; Kumar, Naren Gajenthra; Walsh, Scott W.; Jefferson, Kimberly K.

doi:10.1128/jb.00162-20

Cited by 19 publications

(27 citation statements)

References 41 publications

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“…The species Sneathia amnii and Prevotella amnii have recently been identified as emerging candidates for poor pregnancy outcomes 38 , 39 . In our study, both of these were increased and had a significant association with PTB ( q -value 0.02 and 0.05, respectively; Table 2 ).…”

Section: Discussionmentioning

confidence: 99%

Shotgun sequencing of the vaginal microbiome reveals both a species and functional potential signature of preterm birth

Feehily

Crosby

Walsh

et al. 2020

npj Biofilms Microbiomes

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An association between the vaginal microbiota and preterm birth (PTB) has been reported in several research studies. Population shifts from high proportions of lactobacilli to mixed species communities, as seen with bacterial vaginosis, have been linked to a twofold increased risk of PTB. Despite the increasing number of studies using next-generation sequencing technologies, primarily involving 16S rRNA-based approaches, to investigate the vaginal microbiota during pregnancy, no distinct microbial signature has been associated with PTB. Shotgun metagenomic sequencing offers a powerful tool to reveal community structures and their gene functions at a far greater resolution than amplicon sequencing. In this study, we employ shotgun metagenomic sequencing to compare the vaginal microbiota of women at high risk of preterm birth (n = 35) vs. a low-risk control group (n = 14). Although microbial diversity and richness did not differ between groups, there were significant differences in terms of individual species. In particular, Lactobacillus crispatus was associated with samples from a full-term pregnancy, whereas one community state-type was associated with samples from preterm pregnancies. Furthermore, by predicting gene functions, the functional potential of the preterm microbiota was different from that of full-term equivalent. Taken together, we observed a discrete structural and functional difference in the microbial composition of the vagina in women who deliver preterm. Importance: with an estimated 15 million cases annually, spontaneous preterm birth (PTB) is the leading cause of death in infants under the age of five years. The ability to accurately identify pregnancies at risk of spontaneous PTB is therefore of utmost importance. However, no single cause is attributable. Microbial infection is a known risk factor, yet the role of vaginal microbes is poorly understood. Using high-resolution DNA-sequencing techniques, we investigate the microbial communities present in the vaginal tracts of women deemed high risk for PTB. We confirm that Lactobacillus crispatus is strongly linked to full-term pregnancies, whereas other microbial communities associate with PTB. Importantly, we show that the specific functions of the microbes present in PTB samples differs from FTB samples, highlighting the power of our sequencing approach. This information enables us to begin understanding the specific microbial traits that may be influencing PTB, beyond the presence or absence of microbial taxa.

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Section: Discussionmentioning

confidence: 99%

Shotgun sequencing of the vaginal microbiome reveals both a species and functional potential signature of preterm birth

Feehily

Crosby

Walsh

et al. 2020

npj Biofilms Microbiomes

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“…Several of them are known pathogens, like the food-born pathogen Listeria monocytogenes [23]. Other strains are not yet well characterized, but are known to be able to cause infections, for example Sneathia amnii, which can cause urethritis and can affect pregnancy [24]. Whereas Veillonella species belong to the normal flora in the gastrointestinal tract, mouth and vaginal tract and are rarely related to infections [25].…”

Section: Are Fa-like Proteins Indicators Of Bacterial Pathogenicity?mentioning

confidence: 99%

Discovery of Fibrillar Adhesins across Bacterial Species

Monzon

Lafita

Bateman

2020

Preprint

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BackgroundFibrillar adhesins are long multidomain proteins attached at the cell surface and composed of at least one adhesive domain and multiple tandemly repeated domains, which build an elongated stalk that projects the adhesive domain beyond the bacterial cell surface. They are an important yet understudied class of proteins that mediate interactions of bacteria with their environment. This study aims to characterize fibrillar adhesins in a wide range of bacterial phyla and to identify new fibrillar adhesin-like proteins to improve our understanding of host-bacteria interactions.ResultsBy careful search for fibrillar adhesins in the literature and by computational analysis we identified 75 stalk domains and 24 adhesive domains. Based on the presence of these domains in the UniProt Reference Proteomes database, we identified and analysed 3,388 fibrillar adhesin-like proteins across species of the most common bacterial phyla. We found that the bacterial proteomes with the highest fraction of fibrillar adhesins include several known pathogens. We further enumerate the adhesive and stalk domain combinations found in nature and demonstrate that fibrillar adhesins have complex and variable domain architectures, which differ across species. By analysing the domain architecture of fibrillar adhesins we show that in Gram positive bacteria adhesive domains are mostly positioned at the N-terminus of the protein with the cell surface anchor at the C-terminus, while their positions are more variable in Gram negative bacteria. We provide an open repository of fibrillar adhesin-like proteins and domains to facilitate downstream studies of this class of bacterial surface proteins.ConclusionThis study provides a domain-based characterization of fibrillar adhesins and demonstrates that they are widely found across the main bacterial phyla. We have discovered numerous novel fibrillar adhesins and improved the understanding of how pathogens might adhere to and subsequently invade into host cells.

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“…The role of a cytotoxic haemolysin has recently been unravelled further in 'S. amnii' [57]. The pore-forming cytotoxic exotoxin CptA binds and lyses human red blood cells and damages cells from foetal membranes.…”

Section: Introductionmentioning

confidence: 99%

“…The secreted component A of the protein toxin of a type Vb system is 1881 aa long with a molecular weight of approximately 200 kDa. It seems to be encoded by a sequence that is cotranscribed with a second gene encoding a protein with identity to two-partner system transporters [57]. The 5642 nt toxin sequence demonstrated in strain ‘ S. amnii ’ Sn35 could also be found in strains DSM 16630 and DSM 16631 T , each with only 84 % homology, but not in S.…”

Section: Introductionmentioning

confidence: 99%

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Sneathia vaginalis sp. nov. (Fusobacteriales, Leptotrichiaceae) as a replacement of the species ‘Sneathia amnii’ Harwich et al. 2012 and ‘Leptotrichia amnionii’ Shukla et al. 2002, and emended description of Sneathia Collins et al. 2001

Eisenberg

Gronow

Falgenhauer

et al. 2019

International Journal of Systematic and Evolutionary Microbiology

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Members of the genus Sneathia are fastidious bacteria that predominantly colonise the female genital tract and are significantly associated with reproductive disorders and genital and neonatal disease. From a taxonomical perspective, the genus only comprises the species Sneathia sanguinegens . Numerous reports on a second species, ‘Sneathia amnii’, have been published, but the name has never been validated. The same is the case for ‘Leptotrichia amnionii’, which was previously shown to belong to the same species as ‘Sneathia amnii’. We studied strains DSM 16631T and DSM 16630, which have been identified and deposited as ‘Leptotrichia amnionii’ previously. At the time of isolation, these strains were found to be most closely related to, but clearly different from, Sneathia sanguinegens based on 16S rRNA gene sequence similarities. Both strains proved to be almost indistinguishable from ‘Sneathia amnii’ based on molecular, morphological and physiological traits. The 16S rRNA gene sequence analysis revealed that strain DSM 16631T was assigned to the genus Sneathia with a sequence similarity of 95.47 % to Sneathia sanguinegens CCUG 41628T, followed by type strains of Caviibacter abscessus (93.03 %), Oceanivirga salmonicida (92.68 %) and Oceanivirga miroungae (91.97 %) as the next closely related members of the Leptotrichiaceae . The novel species was also clearly differentiated from other related taxa by core genome phylogeny, average nucleotide and amino acid identities, in silico DNA–DNA hybridization and MALDI-TOF MS. With respect to chemotaxonomic and physiological patterns, strains DSM 16631T and DSM 16630 were again highly similar to Sneathia sanguinegens . On the basis of these data, we propose the novel species Sneathia vaginalis sp. nov. with the type strain DSM 16631T (=CCUG 52977T=CCUG 52889AT) and a second strain DSM 16630 (=CCUG 52976=CCUG 52888) that were both isolated from bloodstream infections in women with puerperal fever in France. The G+C content of the DNA of the type strain is 28.4 mol% and the genome size is 1.28 Mbp. Based on the observed extremely high similarities of genotypic and phenotypic traits of the novel proposed species to those reported for ‘Sneathia amnii’, we recommend using this new name in all further publications on this taxon.

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Identification of a Cytopathogenic Toxin from Sneathia amnii

Cited by 19 publications

References 41 publications

Shotgun sequencing of the vaginal microbiome reveals both a species and functional potential signature of preterm birth

Shotgun sequencing of the vaginal microbiome reveals both a species and functional potential signature of preterm birth

Discovery of Fibrillar Adhesins across Bacterial Species

Sneathia vaginalis sp. nov. (Fusobacteriales, Leptotrichiaceae) as a replacement of the species ‘Sneathia amnii’ Harwich et al. 2012 and ‘Leptotrichia amnionii’ Shukla et al. 2002, and emended description of Sneathia Collins et al. 2001

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