Cytolethal distending toxin (CDT) is found in Gram-negative bacteria, especially in certain Proteobacteria such as the Pasteurellaceae family, including Haemophilus ducreyi and Aggregatibacter (Actinobacillus) actinomycetemcomitans, in the Enterobacteriaceae family and the Campylobacterales order, including the Campylobacter and Helicobacter species. In vitro and in vivo studies have clearly shown that this toxin has a strong effect on cellular physiology (inflammation, immune response modulation, tissue damage). Some works even suggest a potential involvement of CDT in cancers. In this review, we will discuss these different aspects.

Impact of CDT Toxin on Human Diseases

Objectives 
We characterized clinical isolates of Campylobacter using whole-genome sequencing (WGS) for detection of virulence genes, antimicrobial resistance markers and phylogenetic analysis in order to increase the knowledge on the molecular epidemiology of Campylobacter in Ireland, where there are significant gaps due to the widespread in the use of culture independent methods for the diagnosis of campylobacteriosis.


Methods 
WGS was applied to 122 Campylobacter human isolates collected over a 10-years period, from diarrhoeal stool samples submitted for routine enteric screening.


Results 
Genes associated with cytotoxin production such as cdtA, cdtB and cdtC were found in 88%, 89% and 89% isolates, respectively; adherence, colonization and invasion genes such as cadF, dnaJ, racR, iam, virB11 and ciaB were found in 99%, 99%, 98%, 99%, 1% and 80% isolates, respectively. Genetic markers associated with resistance to quinolones (C257T in gyrA), beta-lactams (blaoxa-61) and tetracycline (tet(O)) were present in 43%, 71% and 25% isolates, respectively. The cmeABC operon was present in 94% of isolates. No macrolide or aminoglycoside resistance markers were detected. Phylogenetic analysis showed that 112 isolates were assigned to 29 sequence types grouped into 17 clonal complexes. Four clusters previously unidentified were detected. These results shown the similarity of Irish data compared to what has been described globally.


Conclusions 
WGS has shown a high discriminatory power for cluster detection, demonstrating that its integration in routine laboratory surveillance could improve the detection and management of outbreaks. In addition we were able to demonstrate that virulence genes in clinical Campylobacter infections in Ireland were similar to those known previously. High prevalence of quinolone resistance markers has been found, which has implications for antimicrobial stewardship.

/pdf/molecular-characterization-of-campylobacter-causing-human-4m4zrhxoh4.pdf

Molecular characterization of Campylobacter causing human clinical infection using whole-genome sequencing: Virulence, antimicrobial resistance and phylogeny in Ireland.

In this study, phenotypic and genotypic features of 10 L. garvieae strains isolated from rainbow trout farms were examined with 3 reference strains (Spain, England and ATCC 43921) comperativly. Rapid 32 STREP and conventional microbiologic tests were used for determining phenotipic features of L. garvieae strains. Altough there are diff erences, in Rapid 32 STREP system, between strains in terms of β-Glucuronidase, D-ribose, sorbitol, lactose, raffinose, alanyl-phenylalanyl-proline arylamidase, pyrrolidonyl arylamidase, hippurate hydrolysis, urease tests, all strains have been confirmed as L. garvieae by API web. In RAPD PCR analysis, in which ERIC 2 primer is used, L. garvieae isolates were genotyped within 3 separate clusters according to similarity coefficient index of 70%, and it was detected that a vast majority of isolates with Turkey-origin (8 isolates) belongs to predominant type LG1 genotype. In addition to this, antimicrobial tests of L. garvieae strains shows that there are resistance against gentamycin, neomycin, lincomycin, sulfamethoxazole-trimethoprim, oxytetracycline, erythromycin, amoxicillin, fl orfenicol and doxycycline, which are frequently used on fish in our country.

/pdf/phenotypic-genotypic-characterisation-and-antimicrobial-fbe4llyqfg.pdf

Phenotypic, genotypic characterisation and antimicrobial susceptibility determination of Lactococcus garvieae strains.

There are still major gaps in our understanding of the bacterial factors that influence the outcomes of human Campylobacter jejuni infection. The aim of this study was to compare the virulence-associated features of 192 human C. jejuni strains isolated from hospitalized patients with diarrhoea (150/192, 78.1%), bloody diarrhoea (23/192, 11.9%), gastroenteritis (3/192, 1.6%), ulcerative colitis (3/192, 1.5%), and stomach ache (2/192, 1.0%). Traits were analysed with genotypic and phenotypic methods, including PCR and extracellular matrix protein (ECMP) binding, adhesion, and invasion capacities. Results were studied alongside patient symptoms, but no distinct links with them could be determined. Since the capacity of C. jejuni to invade host epithelial cells is one of its most enigmatic attributes, a high throughput transcriptomic analysis was performed in the third hour of internalization with a C. jejuni strain originally isolated from bloody diarrhoea. Characteristic groups of genes were significantly upregulated, outlining a survival strategy of internalized C. jejuni comprising genes related (1) to oxidative stress; (2) to a protective sheath formed by the capsule, LOS, N-, and O- glycosylation systems; (3) to dynamic metabolic activity supported by different translocases and the membrane-integrated component of the flagellar apparatus; and (4) to hitherto unknown genes.

https://www.mdpi.com/2076-2607/8/4/531/pdf

Virulence Traits of Inpatient Campylobacter jejuni Isolates, and a Transcriptomic Approach to Identify Potential Genes Maintaining Intracellular Survival.

The presence of virulence and cytolethal distending toxin (Cdt) genes was investigated in isolates of Campylobacter jejuni, C. coli, C. lanienae, and C. lari that originated from intestinal contents and gallbladders of clinically healthy sheep. These genes have important roles in the pathogenicity of campylobacters. A total of 363 Campylobacter isolates (221 C. jejuni, 135 C. coli, five C. lanienae, and two C. lari) were used in this study. The frequency of racR, dnaJ, ciaB, pldA, flaA, and cadF virulence genes in all the isolates were determined to be 34.4%, 30%, 24.8%, 30.9%, 95%, and 81.3%, respectively, while the virB11 virulence gene could not be detected in any isolates. CdtA, cdtB, and cdtC genes were detected in 54.5%, 55.9%, and 52.3% of the isolates, respectively. None of the virulence and toxin genes examined here were detected in a total of 19 Campylobacter isolates consisting of 10 C. jejuni and nine C. coli. This is the first study investigating the presence of virulence and toxin genes in a large number of Campylobacter species isolated from clinically healthy sheep by scanning a large area. In addition, this is the first report investigating the presence of virulence and toxin genes in sheep-originated C. lanienae and C. lari isolates.

Investigation of Virulence and Cytolethal Distending Toxin Genes in Campylobacter spp. Isolated from Sheep in Turkey

The genetic diversity of 168 Campylobacter jejuni isolates originating from human (n=30), cattle (n=36), sheep (n=44), dog (n=35), and poultry (n=21) and cdt genes prevalence of the isolates were investigated. To determine the genetic diversity of these strains, random amplified polymorphic DNA-polymerase chain reaction (PCR) using a random primer (M13) was performed. The numbers of genotypes determined in human, cattle, sheep, dog, and poultry isolates were 19, 18, 17, 18, and 6, respectively. To find out the prevalence of cdt genes in C. jejuni isolates simultaneously, a multiplex PCR was performed. The prevalence of the separate cdt genes was found to vary from 69% to 100% for cdtA, 92% to 100% for cdtB, and 39% to 98% for cdtC. These rates without host discriminating were 95%, 98%, and 93% for cdtA, cdtB, and cdtC, respectively. The prevalence of all three cdt genes in strains originating from human, cattle, sheep, dog, and poultry were 87%, 67%, 84%, 89%, and 39%, respectively. These results showed the relatively high genetic heterogeneity and variation of cdt genes among C. jejuni isolates from various sources except for poultry isolates. This study gives baseline data on molecular characterization of C. jejuni strains from different sources.

Molecular typing and cdt genes prevalence of Campylobacter jejuni isolates from various sources

Summary: In this study, the role of Brucella spp. in cattle and sheep abortions among Kayseri region was investigated and predominant subspecies and biovars in this region were determined by conventional and molecular biotyping methods. For this purpose, 61 cattle and 64 sheep abortion material and also 50 human blood isolates were examined. A total of 29 Brucella spp. 17 (27.9%) and 12 (18.7%) of which were isolated from cattle and sheep specimens, respectively) were isolated from animal sources. Both animal and human isolates were typed by conventional and Enhanced AMOS-ERY PCR methods. All Brucella spp. strains isolated from cattle were found to belong to B. abortus biovar 3 and biovar 3b using conventional and molecular typing methods, respectively. All sheep originated Brucella spp. strains and human originated Brucella spp. strains were found to belong to B.melitensis biovar 3 using both conventional and molecular methods. As a result, predominant biovars causing brucellosis in human, cattle and sheep in Kayseri, Turkey were detected. These findings were considered to be useful in prevention and controlling activities for Brucellosis in Turkey. Keywords: Biotyping,

/pdf/conventional-and-molecular-biotyping-of-brucella-strains-2y5fucyv2x.pdf

Conventional and molecular biotyping of Brucella strains isolated from cattle, sheep and human

Handle everyday research tasks with reliable, citation-backed results

Your personal Research Agent to handle research tasks with citation-backed results

Popular Tasks used by Researchers

How can I help with your research?

Meet SciSpace

Get more enhanced response by uploading the PDFs you want me to reference.

No relevant PDFs in your library

SciSpace is the AI research assistant for academics. Run systematic literature reviews on 280M+ papers, and write papers with cited sources. Trusted by 1M+ students, PhDs & researchers.

SciSpace | AI for Research

Analyze PDFs

Code & Manuscripts

Funding & Grants

Literature & Patents

Medical & Clinical Data

Systematic Review

Visualize & Present

Web & Data

Build a Google Scholar-like website for your research.

Build a website

Create charts and images for your research

Create a Chart

Write a paper for submission to a journal

Draft a manuscript

Patent Search

Design eye-catching scientific posters in minutes.

Scientific Poster Generation

Systematic Literature Review

One task is running at the moment. Your messages will be shown right after.

Drag and drop or click here to browse

Loved by <highlight>1 million+</highlight> researchers

Extract a list of specific topics and their sources from unstructured text

Topics

Compare and analyze relevant papers that matches with your search

Papers

Get insights from PDFs and bookmarked papers from your library

My library

Recent searches

Try searching for:

Catch AI-generated content in scholarly and non-scholarly content

{ai} Detector

Ai Writer

Get PDF Summaries, highlighted text explanations 

Chat with PDF

Effortlessly create in-text citations and bibliographies in APA and 2,500 other formats

Citation generator

Get explanations, summaries, and answers on academic papers

Ease up your research workflow with {scispace}'s cohort of exciting AI tools

Elevate your academic writing skills and convey your ideas the way you want

Paraphraser

Explore our range of reading and writing tools

Your file is being prepared and should be ready in a few minutes. If it's a large file, it might take a bit longer. You can close this window, and we'll email you the file when it's done.

You have reached a maximum limit of <strong>{limit}</strong> columns in the table. Remove at least <strong>1</strong> column to add or create another one.

Duygu Percin

Author Tools

Chat about Author

Papers

Molecular typing and cdt genes prevalence of Campylobacter jejuni isolates from various sources

Conventional and molecular biotyping of Brucella strains isolated from cattle, sheep and human