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.

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.

scholarly journals Characterization of a Haemophilus ducreyi Mutant Deficient in Expression of Cytolethal Distending Toxin

1999 ◽  
Vol 67 (8) ◽  
pp. 3900-3908 ◽  
Author(s):  
Marla K. Stevens ◽  
Jo L. Latimer ◽  
Sheryl R. Lumbley ◽  
Christine K. Ward ◽  
Leslie D. Cope ◽  
...  
Keyword(s):  
Gene Cluster ◽  
Hela Cells ◽  
Culture Supernatant ◽  
Haemophilus Ducreyi ◽  
Cytolethal Distending Toxin ◽  
Supernatant Fluid ◽  
Hacat Keratinocytes ◽  
Wild Type ◽  
Insertional Inactivation

ABSTRACT Haemophilus ducreyi expresses a soluble cytolethal distending toxin (CDT) that kills HeLa, HEp-2, and other human epithelial cells in vitro. H. ducreyi CDT activity is encoded by a three-gene cluster (cdtABC), and antibody to the cdtC gene product can neutralize CDT activity in vitro (L. D. Cope, S. R. Lumbley, J. L. Latimer, J. Klesney-Tait, M. K. Stevens, L. S. Johnson, M. Purven, R. S. Munson, Jr., T. Lagergard, J. D. Radolf, and E. J. Hansen, Proc. Natl. Acad. Sci. USA 94:4056–4061, 1997). Culture supernatant fluid from a recombinant Escherichia colistrain containing the H. ducreyi cdtABC gene cluster readily killed both HeLa cells and HaCaT keratinocytes and had a modest inhibitory effect on the growth of human foreskin fibroblasts. Insertional inactivation of the cdtC gene in this recombinant E. coli strain eliminated the ability of this strain to kill HeLa cells and HaCaT keratinocytes. This mutatedH. ducreyi cdtABC gene cluster was used to construct an isogenic H. ducreyi cdtC mutant. Monoclonal antibodies against the H. ducreyi CdtA, CdtB, and CdtC proteins were used to characterize protein expression by this cdtCmutant. Culture supernatant fluid from this H. ducreyi cdtCmutant did not detectably affect any of the human cells used in this study. The presence of the wild-type H. ducreyi cdtC gene in trans in this H. ducreyi mutant restored its ability to express a CDT that killed both HeLa cells and HaCaT keratinocytes. The isogenic H. ducreyi cdtC mutant was shown to be as virulent as its wild-type parent strain in the temperature-dependent rabbit model for experimental chancroid. Lack of expression of the H. ducreyi CdtC protein also did not affect the ability of this H. ducreyi mutant to survive in the skin of rabbits.

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.

Treatments with Nisin and Chelators to Reduce Salmonella and Escherichia coli on Beef†

1995 ◽  
Vol 58 (9) ◽  
pp. 1028-1030 ◽  
Author(s):  
CATHERINE N. CUTTER ◽  
GREGORY R. SIRAGUSA
Keyword(s):  
Escherichia Coli ◽  
Salmonella Typhimurium ◽  
Chelating Agents ◽  
In Vitro Studies ◽  
Sodium Hexametaphosphate ◽  
Escherichia Coli O157 ◽  
E Coli ◽  
Lean Beef

Salmonella typhimurium ATCC 14028 or Escherichia coli O157:H7 attached to lean beef tissue were treated with citrate, lactate, sodium hexametaphosphate, or EDTA, alone or in combination with nisin in simple buffers, and incubated at 4°C for up to 3 days. Lactate with nisin reduced S. typhimurium attached to beef by 040 log10 CFU/cm2, while EDTA and nisin reduced E. coli O157:H7 by 0.42 log10 CFU/cm2. Unlike earlier in vitro studies in which treatments with nisin and chelating agents resulted in reductions of > 4 log10 CFU/cm2, such reductions were not observed in situ.

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.

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.

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