scholarly journals A novel high-content screening approach for the elucidation of C. jejuni biofilm composition and integrity

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Matthew V. X. Whelan ◽  
Jeremy C. Simpson ◽  
Tadhg Ó Cróinín

Abstract Background Campylobacter jejuni is the leading cause of bacterial gastroenteritis worldwide and the main source of infection is contaminated chicken meat. Although this important human pathogen is an obligate microaerophile, it must survive atmospheric oxygen conditions to allow transmission from contaminated chicken meat to humans. It is becoming increasingly evident that formation of biofilm plays a key role in the survival of this organism for extended periods on poultry products. We have recently demonstrated a novel inducible model for the study of adherent C. jejuni biofilm formation under aerobic conditions. By taking advantage of supercoiling mediated gene regulation, incubation of C. jejuni with subinhibitory concentrations of the Gyrase B inhibitor novobiocin was shown to promote the consistent formation of metabolically active adherent biofilm. Results In this study, we implement this model in conjunction with the fluorescent markers: TAMRA (live cells) and SytoX (dead cells, eDNA) to develop a novel systematic high-content imaging approach and describe how it can be implemented to gain quantifiable information about the integrity and extracellular polymeric substance (EPS) composition of adherent C. jejuni biofilm in aerobic conditions. We show that this produces a model with a consistent, homogenous biofilm that can be induced and used to screen a range of inhibitors of biofilm adherence and matrix formation. Conclusions This model allows for the first time a high throughput analysis of C. jejuni biofilms which will be invaluable in enabling researchers to develop mechanisms to disrupt these biofilms and reduce the viability of these bacteria under aerobic conditions.

1984 ◽  
Vol 93 (2) ◽  
pp. 325-332 ◽  
Author(s):  
J. Oosterom ◽  
C. H. den Uyl ◽  
J. R. J. Bänffer ◽  
J. Huisman

SummaryFifty-four Rotterdam patients in which a primary infection withCampylobacter jejunihad been detected (index patients) were compared with 54 control subjects with regard to the consumption and preparation of foods 7 days before onset of illness and the keeping of pet animals. Significantly more index patients than controls had eaten chicken meat (47v. 29;P= 0·0002), particularly at barbecues (14v. 2;P= 0·0015). Marginally more index patients had eaten pork (47v. 39;P= 0·048) or inadequately heated meat (13v. 8), though in the last case numbers were too small to be statistically significant. The consumption of beef or mutton and outdoor eating (other than at barbecues) were essentially the same in both groups. There was no significant association with the keeping of pet animals, although a few more index patients had cage birds than controls (18v. 12).Twenty-one (15%) of 130 household contacts of index patients also suffered from diarrhoea during the same period. Circumstantial evidence pointed to a common source of infection with the index patient in 13 instances (nine households) and probable intrafamilial spread of infection in six instances.Campylobacters were isolated from one of 110 swabs of kitchen work surfaces and eight of 107 swabs taken from lavatory bowls in index households.


2010 ◽  
Vol 76 (7) ◽  
pp. 2122-2128 ◽  
Author(s):  
Mark Reuter ◽  
Arthur Mallett ◽  
Bruce M. Pearson ◽  
Arnoud H. M. van Vliet

ABSTRACT The microaerophilic human pathogen Campylobacter jejuni is the leading cause of food-borne bacterial gastroenteritis in the developed world. During transmission through the food chain and the environment, the organism must survive stressful environmental conditions, particularly high oxygen levels. Biofilm formation has been suggested to play a role in the environmental survival of this organism. In this work we show that C. jejuni NCTC 11168 biofilms developed more rapidly under environmental and food-chain-relevant aerobic conditions (20% O2) than under microaerobic conditions (5% O2, 10% CO2), although final levels of biofilms were comparable after 3 days. Staining of biofilms with Congo red gave results similar to those obtained with the commonly used crystal violet staining. The level of biofilm formation by nonmotile aflagellate strains was lower than that observed for the motile flagellated strain but nonetheless increased under aerobic conditions, suggesting the presence of flagellum-dependent and flagellum-independent mechanisms of biofilm formation in C. jejuni. Moreover, preformed biofilms shed high numbers of viable C. jejuni cells into the culture supernatant independently of the oxygen concentration, suggesting a continuous passive release of cells into the medium rather than a condition-specific active mechanism of dispersal. We conclude that under aerobic or stressful conditions, C. jejuni adapts to a biofilm lifestyle, allowing survival under detrimental conditions, and that such a biofilm can function as a reservoir of viable planktonic cells. The increased level of biofilm formation under aerobic conditions is likely to be an adaptation contributing to the zoonotic lifestyle of C. jejuni.


2019 ◽  
Author(s):  
Laura I FitzGerald ◽  
Luigi Aurelio ◽  
Moore Chen ◽  
Daniel Yuen ◽  
Bim Graham ◽  
...  

Intracellular trafficking governs receptor signalling, pathogenesis, immune responses and the cellular fate of nanomedicines. These processes are typically tracked by confocal microscopy, where colocalization of fluorescent markers implies an interaction or co-compartmentalization. However, this type of analysis is inherently low-throughput, is limited by the resolution of microscopy, and can miss fleeting interactions. To address this, we have developed a localization sensor composed of a quenched and attachable SNAP-tag substrate (SNAPSwitch). SNAPSwitch enables quantitative detection of protein, nucleic acid and nanoparticle trafficking to locations of interest within live cells using flow cytometry. Using this approach, we followed the trafficking of DNA complexes travelling from endosomes into the cytosol and to the nucleus. We also show that antibody targeted to the transferrin (CD71) or hyaluronan (CD44) receptor is initially sorted into different compartments following endocytosis. These results demonstrate SNAPSwitch is a high-throughput and broadly applicable tool to quantitatively track the localization of materials in cells.


2010 ◽  
Vol 18 (3) ◽  
pp. 449-454 ◽  
Author(s):  
S. L. Layton ◽  
M. J. Morgan ◽  
K. Cole ◽  
Y. M. Kwon ◽  
D. J. Donoghue ◽  
...  

ABSTRACTCampylobacteris a leading cause of bacterial gastroenteritis in humans and is often linked to contaminated poultry products. LiveSalmonellavectors expressing three linear peptide epitopes fromCampylobacterproteins Cj0113 (Omp18/CjaD), Cj0982c (CjaA), and Cj0420 (ACE393) were administered to chicks by oral gavage on the day of hatch, and the chicks were challenged withCampylobacter jejunion day 21. All three candidate vaccines produced consistent humoral immune responses with high levels of serum IgG and mucosal secretory IgA (sIgA), with the best response from the Cj0113 peptide-expressing vector.Campylobacterchallenge following vaccination of three candidate vaccine groups decreasedCampylobacterrecovery from the ileum compared to that for controls on day 32. The Cj0113 peptide-expressing vector reducedCampylobacterto below detectable levels. TheSalmonella-vectored Cj0113 subunit vaccine appears to be an excellent candidate for further evaluation as a tool for the reduction ofCampylobacterin poultry for improved food safety.


Animals ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 1718
Author(s):  
Zuamí Villagrán-de la Mora ◽  
María Esther Macías-Rodríguez ◽  
Jenny Arratia-Quijada ◽  
Yesica Sughey Gonzalez-Torres ◽  
Karla Nuño ◽  
...  

Clostridium perfringens (Cp.) is the cause of human foodborne desease. Meat and poultry products are identified as the main source of infection for humans. Cp. can be found in poultry litter, feces, soil, dust, and healthy birds’ intestinal contents. Cp. strains are known to secrete over 20 identified toxins and enzymes that could potentially be the principal virulence factors, capable of degrading mucin, affecting enterocytes, and the small intestine epithelium, involved in necrotic enteritis (NE) pathophysiology, also leading to immunological responses, microbiota modification and anatomical changes. Different environmental and dietary factors can determine the colonization of this microorganism. It has been observed that the incidence of Cp-associated to NE in broilers has increased in countries that have stopped using antibiotic growth promoters. Since the banning of such antibiotic growth promoters, several strategies for Cp. control have been proposed, including dietary modifications, probiotics, prebiotics, synbiotics, phytogenics, organic acids, and vaccines. However, there are aspects of the pathology that still need to be clarified to establish better actions to control and prevention. This paper reviews the current knowledge about Cp. as foodborne pathogen, the pathophysiology of NE, and recent findings on potential strategies for its control.


Author(s):  
Dieter Uhl ◽  
André Jasper

Abstract Wildfires occurred more or less regularly in many Pennsylvanian ecosystems, not only in seasonally dry regions but also in the ever wet tropics. One of the reasons for this was probably the relatively high atmospheric oxygen conditions prevailing during this period. The present study reports evidence for the occurrence of wildfires during deposition of the Upper Pennsylvanian Heusweiler Formation (“Stephanian B”, Kasimovian–Gzhelian) in the intramontane Saar-Nahe (or Saar-Lorraine) Basin in SW-Germany. Based on anatomical features of the charcoal, as well as the co-occurring adpression flora, it seems possible that some of the fires occurred in an ecosystem inhabited by Cordaites. Some of the charcoal fragments exhibit traces of pre-charring decay by fungi, indicating either the consumption of litter by ground or surface fires, or of still standing (partly) dead trees by crown fires.


2014 ◽  
Vol 77 (10) ◽  
pp. 1682-1688 ◽  
Author(s):  
CATHERINE D. CARRILLO ◽  
DANIEL PLANTE ◽  
IRÈNE IUGOVAZ ◽  
ROBYN KENWELL ◽  
GHISLAINE BÉLANGER ◽  
...  

Campylobacter is the most frequent cause of bacterial gastroenteritis in Canada, and the illness is commonly associated with poultry consumption. Whereas Canadian retail poultry is often contaminated with campylobacters, studies on the prevalence of this organism are inconsistent due to variability in sampling and microbiological methodology. To determine the current microbiological status of Canadian poultry, and to evaluate two commonly used microbiological methods, 348 raw poultry samples were collected at retail across Canada over a period of 3 years (2007 to 2010) and were analyzed for the presence of thermophilic Campylobacter species. The overall prevalence of Campylobacter spp. was found to be 42.8% by a combination of the two testing methods, with 33.9% of the samples positive for C. jejuni, 3.7% of the samples positive for C. coli, and 5.2% of the samples positive for both. Variability in Campylobacter spp. prevalence was observed in samples obtained from different regions across Canada and from poultry with or without skin, but this was not statistically significant. In co-contaminated samples, C. jejuni was preferentially recovered from Preston agar compared with mCCDA and Campy-Cefex agar, with an increase in recovery of C. coli on all selective media after 48 h of enrichment. A subset of 214 of the poultry rinses were analyzed by both Health Canada's standard method, MFLP-46 (enrichment in Park and Sanders broth), and a second method requiring enrichment in Bolton broth. Significantly more positive samples were obtained with the MFLP-46 method (40.6%) than with the alternate method (35.0%). This improved recovery with MFLP-46 may be due to the omission of cycloheximide from this method. These results demonstrate that determination of prevalence of Campylobacter spp. on poultry products may be significantly impacted by the choice of microbiological methods used. Canadian poultry continues to be a source of exposure to Campylobacter spp.


2009 ◽  
Vol 75 (23) ◽  
pp. 7310-7318 ◽  
Author(s):  
Nabila Haddad ◽  
Christopher M. Burns ◽  
Jean Michel Bolla ◽  
Hervé Prévost ◽  
Michel Fédérighi ◽  
...  

ABSTRACT Campylobacter jejuni is a leading cause of bacterial gastroenteritis worldwide. Infection generally occurs after ingestion of contaminated poultry products, usually conserved at low temperatures. The mechanisms promoting survival of C. jejuni in the cold remain poorly understood despite several investigations. The present study provides insight into the survival mechanism by establishing the involvement of polynucleotide phosphorylase (PNPase), a 3′-5′ exoribonuclease with multiple biological functions in cold survival. The role of PNPase was demonstrated genetically using strains with altered pnp genes (which encode PNPase) created in C. jejuni F38011 and C. jejuni 81-76 backgrounds. Survival assays carried out at low temperatures (4 and 10°C) revealed a difference of 3 log CFU/ml between the wild-type and the pnp deletion (Δpnp) strains. This did not result from a general requirement for PNPase because survival rates of the strains were similar at higher growth temperatures (37 or 42°C). trans-Complementation with plasmid pNH04 carrying the pnp gene under the control of its natural promoter restored the cold survival phenotype to the pnp deletion strains (at 4 and 10°C) but not to the same level as the wild type. In this study we demonstrate the role of PNPase in low-temperature survival of C. jejuni and therefore attribute a novel biological function to PNPase directly related to human health.


2008 ◽  
Vol 191 (5) ◽  
pp. 1631-1640 ◽  
Author(s):  
Lindsay M. Davis ◽  
Tsutomu Kakuda ◽  
Victor J. DiRita

ABSTRACT Campylobacter jejuni infection is a leading cause of bacterial gastroenteritis in the United States and is acquired primarily through the ingestion of contaminated poultry products. Here, we describe the C. jejuni orthologue of ZnuA in other gram-negative bacteria. ZnuA (Cj0143c) is the periplasmic component of a putative zinc ABC transport system and is encoded on a zinc-dependent operon with Cj0142c and Cj0141c, which encode the other two likely components of the transport system of C. jejuni. Transcription of these genes is zinc dependent. A mutant lacking Cj0143c is growth deficient in zinc-limiting media, as well as in the chick gastrointestinal tract. The protein is glycosylated at asparagine 28, but this modification is dispensable for zinc-limited growth and chick colonization. Affinity-purified FLAG-tagged Cj0143c binds zinc in vitro. Based on our findings and on its homology to E. coli ZnuA, we conclude that Cj0143c encodes the C. jejuni orthologue of ZnuA.


2009 ◽  
Vol 4 (02) ◽  
pp. 107-109 ◽  
Author(s):  
Jorge Ulloa ◽  
Mario Gonzalez ◽  
Carlos Hernandez ◽  
Maria Paz Villanueva ◽  
Heriberto Fernandez

Background: Gastroenteritis caused by Salmonella spp. is mainly related to the consumption of undercooked chicken meat or raw poultry products. The objective of this study was to assess the occurrence of Salmonella spp. in chicken carcasses and giblets commercialized in Southern Chile (Valdivia city). Methodology: A total of 560 samples were collected from four supermarkets and one poultry products dealer, during two periods (autumn-winter and spring-summer periods), and analysed for Salmonella using standard bacteriological procedures. Results: Five out of 280 analyzed carcasses (1.8%) and one out of 280 (0.4%) chicken giblets were Salmonella positive. The isolation frequency of Salmonella spp. considering the total samples analyzed was 1.1%. Salmonella Enteritidis was the only serotype isolated. No significant differences (P > 0.05) in the isolation rates between the autumn-winter and spring-summer periods were found. Conclusion: Salmonella Enteritidis was isolated in low frequency from chicken carcasses and giblets commercialized in Southern Chile (Valdivia city); however, in spite of the low frequency of contaminated samples, this kind of food could be a potential vehicle of Salmonella infection to humans.


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