scholarly journals Microbiota from Specific Pathogen-Free Mice Reduces Campylobacter jejuni Chicken Colonization

Pathogens ◽  
2021 ◽  
Vol 10 (11) ◽  
pp. 1387
Author(s):  
Ayidh Almansour ◽  
Ying Fu ◽  
Tahrir Alenezi ◽  
Mohit Bansal ◽  
Bilal Alrubaye ◽  
...  
Keyword(s):  
Campylobacter Jejuni ◽  
Bacterial Pathogen ◽  
In Vitro Growth ◽  
Specific Pathogen Free ◽  
Effective Prevention ◽  
Effective Strategies ◽  
Gut Colonization ◽  
Specific Pathogen ◽  
Pathogen Colonization

Campylobacter jejuni, a prevalent foodborne bacterial pathogen, is mainly transmitted from poultry with few effective prevention approaches. In this study, we aimed to investigate the role of microbiota on C. jejuni chicken colonization. Microbiota from specific pathogen-free (SPF) mouse stools were collected as SPF-Aerobe and SPF-Anaerobe. Birds were colonized with SPF-Aerobe or SPF-Anaerobe at day 0 and infected with C. jejuni AR101 at day 12. Notably, C. jejuni AR101 colonized at 5.3 and 5.6 log10 C. jejuni CFU/g chicken cecal digesta at days 21 and 28, respectively, while both SPF-Aerobe and SPF-Anaerobe microbiota reduced pathogen colonization. Notably, SPF-Aerobe and SPF-Anaerobe increased cecal phylum Bacteroidetes and reduced phylum Firmicutes compared to those in the nontransplanted birds. Interestingly, microbiota from noninfected chickens, SPF-Aerobe, or SPF-Anaerobe inhibited AR101 in vitro growth, whereas microbiota from infected birds alone failed to reduce pathogen growth. The bacterium Enterobacter102 isolated from infected birds transplanted with SPF-Aerobe inhibited AR101 in vitro growth and reduced pathogen gut colonization in chickens. Together, SPF mouse microbiota was able to colonize chicken gut and reduce C. jejuni chicken colonization. The findings may help the development of effective strategies to reduce C. jejuni chicken contamination and campylobacteriosis.

scholarly journals Metabolic and fitness determinants for in vitro growth and intestinal colonization of the bacterial pathogen Campylobacter jejuni

PLoS Biology ◽  
2017 ◽  
Vol 15 (5) ◽  
pp. e2001390 ◽  
Author(s):  
Beile Gao ◽  
Hanne Vorwerk ◽  
Claudia Huber ◽  
Maria Lara-Tejero ◽  
Juliane Mohr ◽  
...  
Keyword(s):  
Campylobacter Jejuni ◽  
Bacterial Pathogen ◽  
In Vitro Growth ◽  
Intestinal Colonization

scholarly journals Comparative study of egg contamination with Salmonella Heidelberg and Salmonella Typhimurium

2019 ◽  
Vol 56 (1) ◽  
pp. e150479
Author(s):  
Germana Vizzotto Osowski ◽  
Lana Flávia Baron ◽  
Arlei Codebella ◽  
Francisco Noé Fonseca ◽  
Sandra Camile Almeida Mota ◽  
...  
Keyword(s):  
Bacterial Pathogen ◽  
Negative Control ◽  
Infection Model ◽  
Hostile Environment ◽  
Specific Pathogen Free ◽  
Foreign Markets ◽  
Serological Tests ◽  
Statistical Software ◽  
Bacterial Penetration ◽  
Specific Pathogen

Cases of salmonellosis in humans have been associated with consumption of eggs contaminated with this bacterial pathogen due to insufficient heat treatment. The most prevalent serotypes of Salmonella in Brazil include serotypes Enteritidis, Typhimurium, and Heidelberg. The first two serotypes are major causes for eggs to be withheld from sale and for recalls over Salmonella contamination concerns in both domestic and foreign markets. Eggs may be contaminated through transovarian infection (transovarial transmission) due to the presence of the microorganism in the hen’s oviduct and bacterial penetration of the eggshell. There is little data in the literature on the susceptibility of egg contamination and eggshell penetration by Brazilian serotypes of Salmonella. The present study aimed to evaluate the ability of S. Heidelberg and S. Typhimurium serotypes to penetrate through the eggshell and detect these bacteria in the albumen and yolk according to the thickness of the eggshell. SPF (specific-pathogen-free) eggs were artificially contaminated by contact with moist cotton containing Salmonella (15 x 108 CFU/ml). Eggs were divided into the following groups: negative control (not contaminated), S. Heidelberg, and S. Typhimurium. Subsequently, these eggs were incubated at 37°C, and their contents analyzed after 4 h and 24 h of incubation. The evaluation (assessment) of the contamination was performed by traditional bacteriology and confirmed by biochemical and serological tests. Treatments were compared with Fisher’s test using a SAS statistical software. For S. Heidelberg, the percentage of positivity (positive cases) was lower in both albumen and yolk at 4 h and 24 h intervals (33.33% and 3.7%, and 3.7% and 3.7%, respectively) compared to S. Typhimurium (26.63% and 7.41%, and 33.33% and 33.33%, respectively). These findings suggest that the former strain (S. Heidelberg) was unable to survive in the hostile environment of the albumen. In contrast, eggshell thickness had no significant correlation with the number of positive samples. In conclusion, the results obtained in the egg infection model show that the Salmonella strains tested were able to penetrate the eggshell and multiply in both the albumen and yolk and that S. Typhimurium proved to be the most efficient to grow within these portions of the egg.

In Vitro Attachment of Salmonella typhimurium to Chicken Cecal Mucus: Effect of Cations and Pretreatment with Lactobacillus spp. Isolated from the Intestinal Tracts of Chickens

1998 ◽  
Vol 61 (3) ◽  
pp. 265-271 ◽  
Author(s):  
S. E. CRAVEN ◽  
D. D. WILLIAMS
Keyword(s):  
Salmonella Typhimurium ◽  
Chelating Agents ◽  
Culture Supernatant ◽  
Divalent Cations ◽  
Supernatant Fluid ◽  
Specific Pathogen Free ◽  
Intestinal Mucus ◽  
Specific Pathogen ◽  
Lactobacillus Spp

The attachment of radiolabeled Salmonella typhimurium 3333/O cells to immobilized cecal mucus from specific-pathogen-free leghorn chickens was determined in the presence of d-mannose. The attachment of S. typhimurium was inhibited by the chelating agents EDTA and citrate and by lanthanum but was enhanced in the presence of the calcium, barium, and manganese divalent cations. Summary findings of the effect of lectins are included. Attachment of lactobacilli, previously isolated from the intestines of chickens, to mucus was also enhanced by calcium and inhibited by chelators. The pretreatment of immobilized mucus with portions of cultures of five of eight strains of lactobacilli inhibited subsequent attachment of the S. typhimurium strain. Spent culture supernatant fluid and/or washed cells from these cultures inhibited attachment, and inhibition was enhanced by preheating the cells or supernatant fluid at 80°C. Results indicate that S. typhimurium mucus attachment not involving mannosyl-dependent receptors is influenced by presence of cations. Lactobacillus spp. isolated from the intestinal tracts of chickens produce cellular and cell-free components that inhibit this form of attachment to chicken intestinal mucus.

scholarly journals Pyruvate is required for catecholamine-stimulated growth of different strains of Campylobacter jejuni

PeerJ ◽  
2020 ◽  
Vol 8 ◽  
pp. e10011
Author(s):  
Meicen Liu ◽  
Mark Lyte
Keyword(s):  
Escherichia Coli ◽  
Campylobacter Jejuni ◽  
Pathogenic Bacteria ◽  
Intestinal Tract ◽  
Nerve Terminals ◽  
In Vitro Growth ◽  
Gastrointestinal Infections ◽  
Different Strains ◽  
Iron Delivery

Humans and food-producing animals are constantly exposed to and affected by stress. As a consequence of stress, the release of stress-related catecholamines, such as norepinephrine (NE) and dopamine (DA), from nerve terminals in the gastrointestinal tract potentiates both the growth and the virulence of pathogenic bacteria. This may lead to the enhancement of gastrointestinal infections in humans or food-producing animals. Compared with foodborne bacterial pathogens such as Escherichia coli and Salmonella spp., less is known about the effect of stress catecholamines on Campylobacter jejuni subsp. jejuni. The present study focuses on the effect(s) of stress catecholamines DA and NE in iron-restricted media and how they affect the growth of different C. jejuni strains NCTC 11168, 81–176, and ML2126. Results demonstrated that DA- and NE-enhanced growth of C. jejuni in iron-restricted media may involve different mechanisms that cannot be explained by current understanding which relies on catecholamine-mediated iron delivery. Specifically, we found that DA-enhanced growth requires pyruvate, whereas NE-enhanced growth does not. We further report significant strain-specific dependence of C. jejuni growth on various catecholamines in the presence or absence of pyruvate. These data provide novel insights into the effect(s) of stress catecholamines on the in vitro growth of C. jejuni in iron-restricted environments, such as the intestinal tract. They suggest a mechanism by which stress-related catecholamines affect the growth of C. jejuni in the intestinal tract of food-producing animals, which in turn may influence colonization and transmission to humans.

scholarly journals Mycobacterium tuberculosis Rv0991c is a redox-regulated molecular chaperone

2020 ◽  
Author(s):  
Samuel H. Becker ◽  
Kathrin Ulrich ◽  
Avantika Dhabaria ◽  
Beatrix Ueberheide ◽  
William Beavers ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Quality Control ◽  
Molecular Chaperone ◽  
Protein Quality ◽  
Bacterial Pathogen ◽  
Protein Quality Control ◽  
Effective Strategies ◽  
Unfolded Protein ◽  
Hsp70 Chaperone

ABSTRACTThe bacterial pathogen Mycobacterium (M.) tuberculosis is the leading cause of death by an infectious disease among humans. Here, we describe a previously uncharacterized M. tuberculosis protein, Rv0991c, as a molecular chaperone that is activated by oxidation. Rv0991c has homologues in most bacterial lineages and appears to function analogously to the well-characterized Escherichia coli redox-regulated chaperone Hsp33, despite a dissimilar protein sequence. Rv0991c is transcriptionally co-regulated with hsp60 and hsp70 chaperone genes in M. tuberculosis, suggesting that Rv0991c functions with these chaperones in maintaining protein quality control. Supporting this hypothesis, we found that, like oxidized Hsp33, oxidized Rv0991c prevents the aggregation of a model unfolded protein in vitro, and promotes its refolding by the M. tuberculosis Hsp70 chaperone system. Furthermore, Rv0991c interacts with DnaK and associates with many other M. tuberculosis proteins. Importantly, we found Rv0991c is required for the full virulence of M. tuberculosis in mice. We therefore propose that Rv0991c, which we named “Ruc” (redox-regulated protein with unstructured C-terminus), represents a founding member of a new chaperone family that protects M. tuberculosis and other species from proteotoxicity during oxidative stress.IMPORTANCEM. tuberculosis infections are responsible for more than one million human deaths per year. Developing effective strategies to combat this disease requires a greater understanding of M. tuberculosis biology. As in all cells, protein quality control is essential for the viability of M. tuberculosis, which likely faces proteome stress within a host. Here, we identify an M. tuberculosis protein, Ruc, that gains chaperone activity upon oxidation. Ruc represents a previously unrecognized family of redox-regulated chaperones found throughout the bacterial super-kingdom. In addition to elucidating the activity of this chaperone, we found that Ruc was required for full M. tuberculosis virulence in mice. This work contributes to a growing appreciation that oxidative stress may provide a particular strain on protein stability in cells, and may likewise play a role in M. tuberculosis pathogenesis.

Interference between low pathogenic avian influenza H9N2 and avirulent Newcastle diseases viruses in embryonated Specific Pathogen-Free chicken eggs

2021 ◽  
Vol 1 (2) ◽  
pp. 7-10
Author(s):  
Amal Essalah-Bennani ◽  
Asma Fagrach ◽  
Abderrazak El Khantour ◽  
Ouafaa Fassi Fihri ◽  
Moncef Bouzouaia ◽  
...  
Keyword(s):  
Avian Influenza ◽  
Virus Replication ◽  
Model Assessment ◽  
Specific Pathogen Free ◽  
Pathogenic Avian Influenza ◽  
Specific Pathogen ◽  
Pathogenic Avian Influenza Virus ◽  
Low Pathogenic Avian Influenza

Co-infection with low pathogenic avian influenza virus (LPAIV) H9N2 and Newcastle disease virus (NDV) has become a worrying concern for the poultry industry. The problem arises when the hidden virus influences the replication of another suspected virus. Subsequently, misdiagnosis of the actual cause may be ended up as a source of contamination for the other healthy flocks by the spread of the covered-up virus. In this preliminary study, we determined the potential impact of concurrent infection with H9N2 and avirulent NDV (Lasota) on the virus replication in Specific Pathogen-Free embryonated chicken egg (SPF-ECE) model. Assessment of the potential interference phenomena was carried out based on embryonic lesions, mortalities, and virus replication using real-time PCR. Our results showed that H9N2 interferes with LaSota growth, regardless of which infection occurred first. Our obtained preliminary results are a call for scientists to study the interference between LPAIV H9N2 and NDV both in-vivo and in-vitro in more detail.

Bacterial Isolates from the Chicken Gizzard and Ceca with In Vitro Inhibitory Activity against Salmonella typhimurium

1997 ◽  
Vol 60 (2) ◽  
pp. 120-124 ◽  
Author(s):  
DOUGLAS E. COSBY ◽  
STEPHEN E. CRAVEN ◽  
MARK A. HARRISON ◽  
NELSON A. COX
Keyword(s):  
Salmonella Typhimurium ◽  
Inhibitory Activity ◽  
Specific Pathogen Free ◽  
Bacterial Isolates ◽  
Gram Stain ◽  
Ammonium Sulfate Precipitation ◽  
Gram Negative ◽  
Specific Pathogen ◽  
Lactobacillus Spp

Bacterial isolates (197) obtained from the gizzard and ceca of 20 broiler and 40 specific-pathogen-free chickens, 21 days to 8 months of age, were evaluated for inhibitory activity against Salmonella typhimurium. One-hundred forty strains were characterized as gram negative and oxidase negative, typical of the Enterobacteriaceae. Five of the gram-negative and oxidase-negative isolates demonstrated inhibitory activity against six strains of S. typhimurium after 10- and 20-fold concentration and ammonium sulfate precipitation of the cell-free supernatant fluid from a culture grown in M9 minimal medium. Three isolates were identified as lactobacilli, 40 other strains exhibited Gram stain, oxidase, and catalase reactions typical of the Lactobacillus spp., and three known lactobacilli were included in the evaluation. Limited inhibitory activity was exhibited by these 46 isolates when tested against six S. typhimurium strains. Fourteen other strains not characterized as presumptive enterobacteria or lactic acid bacteria demonstrated little or no inhibitory activity against the six test strains.

Hyperoxia inhibits stimulated superoxide release by rat alveolar macrophages

1982 ◽  
Vol 53 (3) ◽  
pp. 685-689 ◽  
Author(s):  
H. J. Forman ◽  
J. J. Williams ◽  
J. Nelson ◽  
R. P. Daniele ◽  
A. B. Fisher
Keyword(s):  
Alveolar Macrophages ◽  
Polymorphonuclear Leukocytes ◽  
Cell Types ◽  
Lavage Fluid ◽  
Significant Decline ◽  
Specific Pathogen Free ◽  
Specific Pathogen ◽  
Cytochrome C Reduction

Factors responsible for the loss of respiratory burst capacity (stimulated extracellular O2-. release) of alveolar macrophages (AM) exposed to prolonged hyperoxia were assessed. Specific pathogen-free rats were exposed to 1 ATA O2 for 24–72 h, and lungs of survivors lavaged. Release of O2-. by cells after addition of concanavalin A, which stimulated AM but not polymorphonuclear leukocytes (PMN), or digitonin, which stimulated both cell types, was measured using cytochrome c reduction +/- superoxide dismutase. O2-. release by AM declined 47.2% (P less than 0.05) after 24 h of hyperoxia and 100% after 60 h. Percent PMN in the lavage was less than 3% at 0–36 h but increased to 16% at 48 h and to 44% at 72 h. Although addition of PMN to AM in vitro caused inhibition of AM O2-. release, the percent PMN required for inhibition was not reached in vivo until after a significant decline in AM O2-.-releasing capacity had already occurred. Cell-free lavage fluid from either control or hyperoxic rats did not affect AM O2-. release. AM in culture for 24 h in hyperoxia lost 76.7% (P less than 0.005) of O2-.-releasing capacity vs. cells incubated in 20% O2, although dye exclusion was unaffected. The results indicate that the major cause of loss of AM O2-. release by hyperoxia is a direct effect of O2 on the cells.

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