Bidirectional transcription of lipooligosaccharide synthesis genes from Campylobacter jejuni

Phongsisay, Vongsavanh; Fry, Benjamin N.

doi:10.1016/j.ijmm.2007.05.003

Cited by 3 publications

(2 citation statements)

References 29 publications

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“…Another interesting finding was the presence of neuA gene in the clusters 2d and 2e, grouping only C. coli strains. This gene is involved in the pathogenesis of GBS being essential for the formation of structures similar to the LOS and human gangliosides [29]. Recently, C. coli strains were identified in faeces of patients with GBS [30,31] and the presence of the epitope-NeuAc, crucial for molecular mimicry, was reported [32].…”

Section: Resultsmentioning

confidence: 99%

Characterization of Antimicrobial Resistance Patterns and Detection of Virulence Genes in Campylobacter Isolates in Italy

Giannatale

Serafino

Zilli

et al. 2014

Sensors

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Campylobacter has developed resistance to several antimicrobial agents over the years, including macrolides, quinolones and fluoroquinolones, becoming a significant public health hazard. A total of 145 strains derived from raw milk, chicken faeces, chicken carcasses, cattle faeces and human faeces collected from various Italian regions, were screened for antimicrobial susceptibility, molecular characterization (SmaI pulsed-field gel electrophoresis) and detection of virulence genes (sequencing and DNA microarray analysis). The prevalence of C. jejuni and C. coli was 62.75% and 37.24% respectively. Antimicrobial susceptibility revealed a high level of resistance for ciprofloxacin (62.76%), tetracycline (55.86%) and nalidixic acid (55.17%). Genotyping of Campylobacter isolates using PFGE revealed a total of 86 unique SmaI patterns. Virulence gene profiles were determined using a new microbial diagnostic microarray composed of 70-mer oligonucleotide probes targeting genes implicated in Campylobacter pathogenicity. Correspondence between PFGE and microarray clusters was observed. Comparisons of PFGE and virulence profiles reflected the high genetic diversity of the strains examined, leading us to speculate different degrees of pathogenicity inside Campylobacter populations.

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Section: Resultsmentioning

confidence: 99%

Characterization of Antimicrobial Resistance Patterns and Detection of Virulence Genes in Campylobacter Isolates in Italy

Giannatale

Serafino

Zilli

et al. 2014

Sensors

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“…Transcriptional fusion analysis was performed to demonstrate whether the difference in leukotoxin expression was as a result of transcriptional fusion between orf X and ltx A operon in the created mutant strains as described previously 37 . To do this we carried out two step RT-PCR.…”

Section: Methodsmentioning

confidence: 99%

Increased leukotoxin production: Characterization of 100 base pairs within the 530 base pair leukotoxin promoter region of Aggregatibacter actinomycetemcomitans

Sampathkumar

Velusamy

Godboley

et al. 2017

Sci Rep

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Aggregatibacter actinomycetemcomitans leukotoxin (LtxA) is a major virulence factor that kills leukocytes permitting it’s escape from host immune surveillance. A. actinomycetemcomitans strains can produce high or low levels of toxin. Genetic differences reside in the “so called JP2” ltxA promoter region. These hyper-leukotoxin producing strains with the 530 bp deletion have been studied in detail. However, regions contained within the 530 bp deletion that could be responsible for modulation of leukotoxin production have not been defined. Here, we report, for the first time, on regions within the 530 bp that are responsible for high-levels of ltxA expression. We constructed a deletion of 530 bps in a primate isolate of A. actinomycetemcomitans, which produced leukotoxin equivalent to the JP2 strain. We then constructed sequential deletions in regions that span the 530 bps. Results indicated that expression of the ltxA transcript was reduced by a potential transcriptional terminator in promoter region 298 to 397 with a ΔG = −7.9 kcal/mol. We also confirmed previous findings that transcriptional fusion between the orfX region and ltxC increased ltxA expression. In conclusion, we constructed a hyper-leukotoxin producing A. actinomycetemcomitans strain and identified a terminator located in the promoter region extending from 298–397 that alters ltxA expression.

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Antiganglioside antibodies and their pathophysiological effects on Guillain-Barre syndrome and related disorders--A review

2009

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Guillain-Barré syndrome (GBS) is an acute immune-mediated polyradiculoneuropathy which can cause acute quadriplegia. Infection with micro-organisms, including Campylobacter jejuni (C. jejuni), Haemophilus influenzae, and Cytomegalovirus (CMV), is recognized as a main triggering event for the disease. Lipooligosaccharide (LOS) genes are responsible for the formation of human ganglioside-like LOS structures in infectious micro-organisms that can induce GBS. Molecular mimicry of LOSs on the surface of infectious agents and of ganglioside antigens on neural cells is thought to induce cross-reactive humoral and cellular immune responses. Patients with GBS develop antibodies against those gangliosides, resulting in autoimmune targeting of peripheral nerve sites, leading to neural damage. Heterogeneity of ganglioside expression in the peripheral nervous system (PNS) may underlie the differential clinical manifestation of the GBS variants. Recent studies demonstrate that some GBS sera react with ganglioside complexes consisting of two different gangliosides, such as GD1a and GD1b, or GM1 and GD1a, but not with each constituent ganglioside alone. The discovery of antiganglioside complex antibodies not only improves the detection rate of autoantibodies in GBS, but also provides a new concept in the antibody-antigen interaction through clustered carbohydrate epitopes. Although ganglioside mimicry is one of the possible etiological causes of GBS, unidentified factors may also contribute to the pathogenesis of GBS. While GBS is not considered a genetic disease, host factors, particularly human lymphocyte antigen type, appear to have a role in the pathogenesis of GBS following C. jejuni infection.

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Bidirectional transcription of lipooligosaccharide synthesis genes from Campylobacter jejuni

Cited by 3 publications

References 29 publications

Characterization of Antimicrobial Resistance Patterns and Detection of Virulence Genes in Campylobacter Isolates in Italy

Characterization of Antimicrobial Resistance Patterns and Detection of Virulence Genes in Campylobacter Isolates in Italy

Increased leukotoxin production: Characterization of 100 base pairs within the 530 base pair leukotoxin promoter region of Aggregatibacter actinomycetemcomitans

Antiganglioside antibodies and their pathophysiological effects on Guillain-Barre syndrome and related disorders--A review

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