scholarly journals Genetic and chemical differentiation ofCampylobacter coliandCampylobacter jejunilipooligosaccharide pathways

2016 ◽  
Author(s):  
Alejandra Culebro ◽  
Joana Revez ◽  
Ben Pascoe ◽  
Yasmin Friedmann ◽  
Matthew D Hitchings ◽  
...  

ABSTRACTDespite the importance of lipooligosaccharides (LOS) in the pathogenicity of campylobacteriosis, little is known about the genetic and phenotypic diversity of LOS inC. coli. In this study, we investigated the distribution of LOS locus classes among a large collection of unrelatedC. coliisolates sampled from several different host species. Furthermore, we pairedC. coligenomic information and LOS chemical composition for the first time to identify mechanisms consistent with the generation of LOS phenotypic heterogeneity. After classifying three new LOS locus classes, only 85% of the 144 isolates tested were assigned to a class, suggesting higher genetic diversity than previously thought. This genetic diversity is at the basis of a completely unexplored LOS structure heterogeneity. Mass spectrometry analysis of the LOS of nine isolates, representing four different LOS classes, identified two features distinguishingC. coliLOS fromC. jejuni’s. GlcN-GlcN disaccharides were present in the lipid A backbone in contrast to the GlcN3N-GlcN backbone observed inC. jejuni. Moreover, despite that many of the genes putatively involved in Qui3pNAcyl were absence in the genomes of various isolates, this rare sugar was found in the outer core of allC. coli. Therefore, regardless the high genetic diversity of LOS biosynthes is locus inC. coli, we identified species-specific phenotypic features ofC. coliLOS which might explain differences betweenC. jejuniandC. coliin terms of population dynamics and host adaptation.Depositories (where applicable)The whole genome sequences ofC. coliare publicly available on the RAST server (http://rast.nmpdr.org) with guest account (login and password ‘guest’) under IDs: 195.91, 195.96-195.119, 195.124-195.126, 195.128-195.130, 195.133, 195.134, 6666666.94320

2016 ◽  
Vol 198 (20) ◽  
pp. 2829-2840 ◽  
Author(s):  
Alejandra Culebro ◽  
Joana Revez ◽  
Ben Pascoe ◽  
Yasmin Friedmann ◽  
Matthew D. Hitchings ◽  
...  

ABSTRACTDespite the importance of lipooligosaccharides (LOSs) in the pathogenicity of campylobacteriosis, little is known about the genetic and phenotypic diversity of LOS inCampylobacter coli. In this study, we investigated the distribution of LOS locus classes among a large collection of unrelatedC. coliisolates sampled from several different host species. Furthermore, we pairedC. coligenomic information and LOS chemical composition for the first time to investigate possible associations between LOS locus class sequence diversity and biochemical heterogeneity. After identifying three new LOS locus classes, only 85% of the 144 isolates tested were assigned to a class, suggesting higher genetic diversity than previously thought. This genetic diversity is at the basis of a completely unexplored LOS structural heterogeneity. Mass spectrometry analysis of the LOSs of nine isolates, representing four different LOS classes, identified two features distinguishingC. coliLOS from that ofCampylobacter jejuni. 2-Amino-2-deoxy-d-glucose (GlcN)–GlcN disaccharides were present in the lipid A backbone, in contrast to the β-1′-6-linked 3-diamino-2,3-dideoxy-d-glucopyranose (GlcN3N)–GlcN backbone observed inC. jejuni. Moreover, despite the fact that many of the genes putatively involved in 3-acylamino-3,6-dideoxy-d-glucose (Quip3NAcyl) were apparently absent from the genomes of various isolates, this rare sugar was found in the outer core of allC. coliisolates. Therefore, regardless of the high genetic diversity of the LOS biosynthesis locus inC. coli, we identified species-specific phenotypic features ofC. coliLOS that might explain differences betweenC. jejuniandC. coliin terms of population dynamics and host adaptation.IMPORTANCEDespite the importance ofC. colito human health and its controversial role as a causative agent of Guillain-Barré syndrome, little is known about the genetic and phenotypic diversity ofC. coliLOSs. Therefore, we pairedC. coligenomic information and LOS chemical composition for the first time to address this paucity of information. We identified two species-specific phenotypic features ofC. coliLOS, which might contribute to elucidating the reasons behind the differences betweenC. jejuniandC. coliin terms of population dynamics and host adaptation.


Biochimie ◽  
2017 ◽  
Vol 141 ◽  
pp. 16-20 ◽  
Author(s):  
Camille B. Robert ◽  
Michael Thomson ◽  
Alain Vercellone ◽  
Francesca Gardner ◽  
Robert K. Ernst ◽  
...  

2018 ◽  
Vol 2018 ◽  
pp. 1-14 ◽  
Author(s):  
Aitor Martinez ◽  
Juanma Ramirez ◽  
Nerea Osinalde ◽  
Jesus M. Arizmendi ◽  
Ugo Mayor

Both Parkin and UBE3A are E3 ubiquitin ligases whose mutations result in severe brain dysfunction. Several of their substrates have been identified using cell culture models in combination with proteasome inhibitors, but not in more physiological settings. We recently developed theUbbiostrategy to isolate ubiquitinated proteins in flies and have now identified by mass spectrometry analysis the neuronal proteins differentially ubiquitinated by those ligases. This is an example of how flies can be used to provide biological material in order to reveal steady state substrates of disease causing genes. Collectively our results provide new leads to the possible physiological functions of the activity of those two disease causing E3 ligases. Particularly, in the case of Parkin the novelty of our data originates from the experimental setup, which is not overtly biased by acute mitochondrial depolarisation. In the case of UBE3A, it is the first time that a nonbiased screen for its neuronal substrates has been reported.


2010 ◽  
Vol 192 (8) ◽  
pp. 2044-2052 ◽  
Author(s):  
Jyl S. Matson ◽  
Hyun Ju Yoo ◽  
Kristina Hakansson ◽  
Victor J. DiRita

ABSTRACTAntimicrobial peptides are critical for innate antibacterial defense. Both Gram-negative and Gram-positive microbes have mechanisms to alter their surfaces and resist killing by antimicrobial peptides. InVibrio cholerae, two natural epidemic biotypes, classical and El Tor, exhibit distinct phenotypes with respect to sensitivity to the peptide antibiotic polymyxin B: classical strains are sensitive and El Tor strains are relatively resistant. We carried out mutant screens of both biotypes, aiming to identify classicalV. choleraemutants resistant to polymyxin B and El TorV. choleraemutants sensitive to polymyxin B. Insertions in a gene annotatedmsbB(encoding a predicted lipid A secondary acyltransferase) answered both screens, implicating its activity in antimicrobial peptide resistance ofV. cholerae. Analysis of a defined mutation in the El Tor biotype demonstrated thatmsbBis required for resistance to all antimicrobial peptides tested. Mutation ofmsbBin a classical strain resulted in reduced resistance to several antimicrobial peptides but in no significant change in resistance to polymyxin B.msbBmutants of both biotypes showed decreased colonization of infant mice, with a more pronounced defect observed for the El Tor mutant. Mass spectrometry analysis showed that lipid A of themsbBmutant for both biotypes was underacylated compared to lipid A of the wild-type isolates, confirming that MsbB is a functional acyltransferase inV. cholerae.


2018 ◽  
Vol 7 (11) ◽  
Author(s):  
Adelaide Milani ◽  
Gianpiero Zamperin ◽  
Alice Fusaro ◽  
Annalisa Salviato ◽  
Luca Bano ◽  
...  

Using a metagenomics approach, we were able to determine for the first time the full-genome sequence of a psittacine adenovirus 1 isolate that was recovered from the liver of a dead Senegal parrot (Poicephalus senegalus) in Italy. The results of the phylogenetic investigations revealed the existence of high genetic diversity among adenoviruses circulating in psittacine birds.


Viruses ◽  
2018 ◽  
Vol 10 (7) ◽  
pp. 385 ◽  
Author(s):  
Asimina Katsiani ◽  
Varvara Maliogka ◽  
Nikolaos Katis ◽  
Laurence Svanella-Dumas ◽  
Antonio Olmos ◽  
...  

Little cherry virus 1 (LChV1, Velarivirus, Closteroviridae) is a widespread pathogen of sweet or sour cherry and other Prunus species, which exhibits high genetic diversity and lacks a putative efficient transmission vector. Thus far, four distinct phylogenetic clusters of LChV1 have been described, including isolates from different Prunus species. The recent application of high throughput sequencing (HTS) technologies in fruit tree virology has facilitated the acquisition of new viral genomes and the study of virus diversity. In the present work, several new LChV1 isolates from different countries were fully sequenced using different HTS approaches. Our results reveal the presence of further genetic diversity within the LChV1 species. Interestingly, mixed infections of the same sweet cherry tree with different LChV1 variants were identified for the first time. Taken together, the high intra-host and intra-species diversities of LChV1 might affect its pathogenicity and have clear implications for its accurate diagnostics.


2002 ◽  
Vol 184 (3) ◽  
pp. 629-635 ◽  
Author(s):  
J. M. Nieto ◽  
C. Madrid ◽  
E. Miquelay ◽  
J. L. Parra ◽  
S. Rodríguez ◽  
...  

ABSTRACT Escherichia coli nucleoid-associated H-NS protein interacts with the Hha protein, a member of a new family of global modulators that also includes the YmoA protein from Yersinia enterocolitica. This interaction has been found to be involved in the regulation of the expression of the toxin α-hemolysin. In this study, we further characterize the interaction between H-NS and Hha. We show that the presence of DNA in preparations of copurified His-Hha and H-NS is not directly implicated in the interaction between the proteins. The precise molecular mass of the H-NS protein retained by Hha, obtained by mass spectrometry analysis, does not show any posttranslational modification other than removal of the N-terminal Met residue. We constructed an H-NS-His recombinant protein and found that, as expected, it interacts with Hha. We used a Ni2+-nitrilotriacetic acid agarose method for affinity chromatography copurification of proteins to identify the H-NS protein of Y. enterocolitica. We constructed a six-His-YmoA recombinant protein derived from YmoA, the homologue of Hha in Y. enterocolitica, and found that it interacts with Y. enterocolitica H-NS. We also cloned and sequenced the hns gene of this microorganism. In the course of these experiments we found that His-YmoA can also retain H-NS from E. coli. We also found that the hns gene of Y. enterocolitica can complement an hns mutation of E. coli. Finally, we describe for the first time systematic characterization of missense mutant alleles of hha and truncated Hha′ proteins, and we report a striking and previously unnoticed similarity of the Hha family of proteins to the oligomerization domain of the H-NS proteins.


2008 ◽  
Vol 76 (12) ◽  
pp. 5777-5789 ◽  
Author(s):  
Hideyuki Takahashi ◽  
Russel W. Carlson ◽  
Artur Muszynski ◽  
Biswa Choudhury ◽  
Kwang Sik Kim ◽  
...  

ABSTRACT The lipooligosaccharide (LOS) of Neisseria meningitidis can be decorated with phosphoethanolamine (PEA) at the 4′ position of lipid A and at the O-3 and O-6 positions of the inner core of the heptose II residue. The biological role of PEA modification in N. meningitidis remains unclear. During the course of our studies to elucidate the pathogenicity of the ST-2032 (invasive) meningococcal clonal group, disruption of lptA, the gene that encodes the PEA transferase for 4′ lipid A, led to a approximately 10-fold decrease in N. meningitidis adhesion to four kinds of human endothelial and epithelial cell lines at an multiplicity of infection of 5,000. Complementation of the lptA gene in a ΔlptA mutant restored wild-type adherence. By matrix-assisted laser desorption ionization-time-of-flight mass spectrometry analysis, PEA was lost from the lipid A of the ΔlptA mutant compared to that of the wild-type strain. The effect of LptA on meningococcal adhesion was independent of other adhesins such as pili, Opc, Opa, and PilC but was inhibited by the presence of capsule. These results indicate that modification of LOS with PEA by LptA enhances meningococcal adhesion to human endothelial and epithelial cells in unencapsulated N. meningitidis.


Author(s):  
Marie Bicikova ◽  
Martin Hill ◽  
Daniela Ripova ◽  
Pavel Mohr

AbstractThe role of GABAergic pathways in the pathophysiology of schizophrenia is generally accepted. Therefore, the information concerning alterations of the steroid metabolome associated with the disease and/or its treatment is of interest with regard to the pathophysiology of the disease. Hence, we assessed 18 serum steroids and steroid polar conjugates in a group of drug-naive patients (13 adult men) and after 6-months therapy by atypical antipsychotics and age-matched controls (19 men) using gas chromatography-mass spectrometry analysis. This study, for the first time, demonstrates the altered circulating GABAergic steroids in schizophrenic men as well as the effect of the therapy with two types of atypical antipsychotics. The GABAergic androsterone (3α5α) and etiocholanolone (3α5β) are reduced in schizophrenic men but the therapy with atypical antipsychotics reinstates their levels. This reinstatement could be of importance when considering that the GABAergic substances generally improve the well-being of patients. In addition to the unconjugated androsterone, being the most abundant GABAergic steroid in men, most of the other GABAergic steroids also tended to decrease in the patients. By contrast, the conjugated 5β-pregnanolone isomers were elevated in the patients. In conclusion, although schizophrenia status in adult men is associated with unfavorable alterations in neuroactive steroids, the treatment with antipsychotics could at least partly reinstate their circulating levels.


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