scholarly journals A Novel Natural Antimicrobial Can Reduce the in vitro and in vivo Pathogenicity of T6SS Positive Campylobacter jejuni and Campylobacter coli Chicken Isolates

2018 ◽  
Vol 9 ◽  
Author(s):  
Filip Sima ◽  
Alexandros Ch. Stratakos ◽  
Patrick Ward ◽  
Mark Linton ◽  
Carmel Kelly ◽  
...  
2016 ◽  
Vol 2016 ◽  
pp. 1-9 ◽  
Author(s):  
Marine Meunier ◽  
Muriel Guyard-Nicodème ◽  
Edouard Hirchaud ◽  
Alberto Parra ◽  
Marianne Chemaly ◽  
...  

Campylobacteriosis is the most prevalent bacterial foodborne gastroenteritis affecting humans in the European Union. Human cases are mainly due toCampylobacter jejuniorCampylobacter coli, and contamination is associated with the handling and/or consumption of poultry meat. In fact, poultry constitutes the bacteria’s main reservoir. A promising way of decreasing the incidence of campylobacteriosis in humans would be to decrease avian colonization. Poultry vaccination is of potential for this purpose. However, despite many studies, there is currently no vaccine available on the market to reduce the intestinalCampylobacterload in chickens. It is essential to identify and characterize new vaccine antigens. This study applied the reverse vaccinology approach to detect new vaccine candidates. The main criteria used to select immune proteins were localization, antigenicity, and number of B-epitopes. Fourteen proteins were identified as potential vaccine antigens.In vitroandin vivoexperiments now need to be performed to validate the immune and protective power of these newly identified antigens.


2015 ◽  
Vol 59 (7) ◽  
pp. 3880-3886 ◽  
Author(s):  
Jeremiah G. Johnson ◽  
Caroline Yuhas ◽  
Thomas J. McQuade ◽  
Martha J. Larsen ◽  
Victor J. DiRita

ABSTRACTCampylobacter jejuniis a major cause of food-borne illness due to its ability to reside within the gastrointestinal tracts of chickens. Multiple studies have identified the flagella ofC. jejunias a major determinant of chicken colonization. An inhibitor screen of approximately 147,000 small molecules was performed to identify compounds that are able to inhibit flagellar expression in a reporter strain ofC. jejuni. Several compounds that modestly inhibited motility of wild-typeC. jejuniin standard assays were identified, as were a number of small molecules that robustly inhibitedC. jejunigrowth,in vitro. Examination of similar bacterial screens found that many of these small molecules inhibited only the growth ofC. jejuni. Follow-up assays demonstrated inhibition of other strains ofC. jejuniandCampylobacter colibut no inhibition of the closely relatedHelicobacter pylori. The compounds were determined to be bacteriostatic and nontoxic to eukaryotic cells. Preliminary results from a day-of-hatch chick model of colonization suggest that at least one of the compounds demonstrates promise for reducingCampylobactercolonization loadsin vivo, although further medicinal chemistry may be required to enhance bioavailability.


Gut Pathogens ◽  
2021 ◽  
Vol 13 (1) ◽  
Author(s):  
De Xi ◽  
Lukas Hofmann ◽  
Thomas Alter ◽  
Ralf Einspanier ◽  
Stefan Bereswill ◽  
...  

Abstract Background Campylobacter jejuni (C. jejuni) infections are of increasing importance worldwide. As a typical mucosal pathogen, the interaction of C. jejuni with mucins is a prominent step in the colonisation of mucosal surfaces. Despite recent advances in understanding the interaction between bacterial pathogens and host mucins, the mechanisms of mucin glycosylation during intestinal C. jejuni infection remain largely unclear. This prompted us to identify relevant regulatory networks that are concerted by miRNAs and could play a role in the mucin modification and interaction. Results We firstly used a human intestinal in vitro model, in which we observed altered transcription of MUC2 and TFF3 upon C. jejuni NCTC 11168 infection. Using a combined approach consisting of in silico analysis together with in vitro expression analysis, we identified the conserved miRNAs miR-125a-5p and miR-615-3p associated with MUC2 and TFF3. Further pathway analyses showed that both miRNAs appear to regulate glycosyltransferases, which are related to the KEGG pathway ‘Mucin type O-glycan biosynthesis’. To validate the proposed interactions, we applied an in vivo approach utilising a well-established secondary abiotic IL-10−/− mouse model for infection with C. jejuni 81-176. In colonic tissue samples, we confirmed infection-dependent aberrant transcription of MUC2 and TFF3. Moreover, two predicted glycosyltransferases, the sialyltransferases ST3GAL1 and ST3GAL2, exhibited inversely correlated transcriptional levels compared to the expression of the identified miRNAs miR-125a-5p and miR-615-3p, respectively. In this study, we mainly focused on the interaction between miR-615-3p and ST3GAL2 and were able to demonstrate their molecular interaction using luciferase reporter assays and RNAi. Detection of ST3GAL2 in murine colonic tissue by immunofluorescence demonstrated reduced intensity after C. jejuni 81-176 infection and was thus consistent with the observations made above. Conclusions We report here for the first time the regulation of glycosyltransferases by miRNAs during murine infection with C. jejuni 81-176. Our data suggest that mucin type O-glycan biosynthesis is concerted by the interplay of miRNAs and glycosyltransferases, which could determine the shape of intestinal glycosylated proteins during infection.


2021 ◽  
Author(s):  
Victoria L. Jeter ◽  
Jorge C. Escalante-Semerena

Posttranslational modifications are mechanisms for rapid control of protein function used by cells from all domains of life. Acetylation of the epsilon amino group ( N ε ) of an active-site lysine of the AMP-forming acetyl-CoA synthetase (Acs) enzyme is the paradigm for the posttranslational control of the activity of metabolic enzymes. In bacteria, the alluded active-site lysine of Acs enzymes can be modified by a number of different GCN5-type N -acetyltransferases (GNATs). Acs activity is lost as a result of acetylation, and restored by deacetylation. Using a heterologous host, we show that Campylobacter jejuni NCTC11168 synthesizes enzymes that control Acs function by reversible lysine acetylation (RLA). This work validates the function of gene products encoded by the cj1537c , cj1715, and cj1050c loci, namely the AMP-forming acetate:CoA ligase ( Cj Acs), a type IV GCN5-type lysine acetyltransferase (GNAT, hereafter Cj LatA), and a NAD + -dependent (class III) sirtuin deacylase ( Cj CobB), respectively. To our knowledge, these are the first in vivo and in vitro data on C. jejuni enzymes that control the activity of Cj Acs. IMPORTANCE This work is important because it provides the experimental evidence needed to support the assignment of function to three key enzymes, two of which control the reversible posttranslational modification of an active-site lysyl residue of the central metabolic enzyme acetyl-CoA synthetase ( Cj Acs). We can now generate Campylobacter jejuni mutant strains defective in these functions, so we can establish the conditions in which this mode of regulation of Cj Acs is triggered in this bacterium. Such knowledge may provide new therapeutic strategies for the control of this pathogen.


2010 ◽  
Vol 10 (1) ◽  
pp. 232 ◽  
Author(s):  
Carla M Carvalho ◽  
Ben W Gannon ◽  
Deborah E Halfhide ◽  
Silvio B Santos ◽  
Christine M Hayes ◽  
...  

2019 ◽  
Vol 201 (8) ◽  
Author(s):  
Alejandra Kolehmainen ◽  
Mirko Rossi ◽  
Jacek Stupak ◽  
Jianjun Li ◽  
Michel Gilbert ◽  
...  

ABSTRACTCampylobacter jejuniandCampylobacter coliare the most common causes of bacterial gastroenteritis in the world. Ganglioside mimicry byC. jejunilipooligosaccharide (LOS) is the triggering factor of Guillain-Barré syndrome (GBS), an acute polyneuropathy. Sialyltransferases from glycosyltransferase family 42 (GT-42) are essential for the expression of ganglioside mimics inC. jejuni. Recently, two novel GT-42 genes,cstIVandcstV, have been identified inC. coli. Despite being present in ∼11% of currently availableC. coligenomes, the biological role ofcstIVandcstVis unknown. In the present investigation, mutation studies with two strains expressing eithercstIVorcstVwere performed and mass spectrometry was used to investigate differences in the chemical composition of LOS. Attempts were made to identify donor and acceptor molecules usingin vitroactivity tests with recombinant GT-42 enzymes. Here we show that CstIV and CstV are involved inC. coliLOS biosynthesis. In particular,cstVis associated with LOS sialylation, whilecstIVis linked to the addition of a diacetylated nonulosonic acid residue.IMPORTANCEDespite the fact thatCampylobacter colia major foodborne pathogen, its glycobiology has been largely neglected. The genetic makeup of theC. colilipooligosaccharide biosynthesis locus was largely unknown until recently.C. coliharbors a large set of genes associated with lipooligosaccharide biosynthesis, including genes for several putative glycosyltransferases involved in the synthesis of sialylated lipooligosaccharide inCampylobacter jejuni. In the present study,C. coliwas found to express lipooligosaccharide structures containing sialic acid and other nonulosonate acids. These findings have a strong impact on our understanding ofC. coliecology, host-pathogen interaction, and pathogenesis.


2019 ◽  
Vol 7 (12) ◽  
pp. 679 ◽  
Author(s):  
Laurette Pinkerton ◽  
Mark Linton ◽  
Carmel Kelly ◽  
Patrick Ward ◽  
Gratiela Gradisteanu Pircalabioru ◽  
...  

Reducing acute mortality in aquatic crustaceans using natural alternatives to antibiotics has become a necessity, firstly for its positive impact on the aquaculture industry and, secondly, because the extensive use of antibiotics may lead to increased levels of drug resistance in pathogenic microorganisms. This study aimed to investigate the effect of a mixture of natural antimicrobials on the in vitro and in vivo virulence abilities of Type VI secretion system (T6SS)-positive Vibrio parahaemolyticus (A3 and D4), strains known as having potentially harmful health consequences for aquatic crustaceans and consumers. Herein, we report that a natural antimicrobial mixture (A3009) was capable of significantly reducing the virulence of V. parahaemolyticus strains A3 and D4 in an in vitro infection model, using the fish cell line CHSE-214, an effect which correlates with the bacterial downregulation of hcp1 and hcp2 gene expression and with the ability of the antimicrobial to efficiently retain low cytotoxic levels (p < 0.001). We show for the first time that a natural antimicrobial is able to significantly reduce the mortality of shrimps in a challenge experiment and is able to significantly attenuate H2O2 release during infection (p < 0.001), indicating that it could harbor positive intestinal redox balance effects.


2006 ◽  
Vol 50 (3) ◽  
pp. 1086-1088 ◽  
Author(s):  
Daniela Schönberg-Norio ◽  
Marja-Liisa Hänninen ◽  
Marja-Leena Katila ◽  
Suvi-Sirkku Kaukoranta ◽  
Markku Koskela ◽  
...  

ABSTRACT The in vitro susceptibilities of 478 Campylobacter jejuni and Campylobacter coli strains isolated from Finnish subjects during 2002 to 2004 were determined. Susceptibility to erythromycin remained high, and telithromycin did not offer any advantage over erythromycin. Reduced susceptibilities to fluoroquinolones and doxycycline were detected almost exclusively among isolates of foreign origin.


2008 ◽  
Vol 190 (6) ◽  
pp. 1879-1890 ◽  
Author(s):  
Baoqing Guo ◽  
Ying Wang ◽  
Feng Shi ◽  
Yi-Wen Barton ◽  
Paul Plummer ◽  
...  

ABSTRACT CmeR functions as a transcriptional repressor modulating the expression of the multidrug efflux pump CmeABC in Campylobacter jejuni. To determine if CmeR also regulates other genes in C. jejuni, we compared the transcriptome of the cmeR mutant with that of the wild-type strain using a DNA microarray. This comparison identified 28 genes that showed a ≥2-fold change in expression in the cmeR mutant. Independent real-time quantitative reverse transcription-PCR experiments confirmed 27 of the 28 differentially expressed genes. The CmeR-regulated genes encode membrane transporters, proteins involved in C4-dicarboxylate transport and utilization, enzymes for biosynthesis of capsular polysaccharide, and hypothetical proteins with unknown functions. Among the genes whose expression was upregulated in the cmeR mutant, Cj0561c (encoding a putative periplasmic protein) showed the greatest increase in expression. Subsequent experiments demonstrated that this gene is strongly repressed by CmeR. The presence of the known CmeR-binding site, an inverted repeat of TGTAAT, in the promoter region of Cj0561c suggests that CmeR directly inhibits the transcription of Cj0561c. Similar to expression of cmeABC, transcription of Cj0561c is strongly induced by bile compounds, which are normally present in the intestinal tracts of animals. Inactivation of Cj0561c did not affect the susceptibility of C. jejuni to antimicrobial compounds in vitro but reduced the fitness of C. jejuni in chickens. Loss-of-function mutation of cmeR severely reduced the ability of C. jejuni to colonize chickens. Together, these findings indicate that CmeR governs the expression of multiple genes with diverse functions and is required for Campylobacter adaptation in the chicken host.


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