scholarly journals Pathogenicity of Chlamydia gallinacea in chickens after oral inoculation

2021 ◽  
pp. 109166
Author(s):  
Marloes Heijne ◽  
Jeanet van der Goot ◽  
Herma Buys ◽  
Annemieke Dinkla ◽  
Hendrik Jan Roest ◽  
...  
Keyword(s):  
Oral Inoculation

Bacteriophages reduce Escherichia coli O157:H7 levels in experimentally inoculated sheep

2009 ◽  
Vol 89 (2) ◽  
pp. 285-293 ◽  
Author(s):  
S J Bach ◽  
R P Johnson ◽  
K. Stanford ◽  
T A McAllister
Keyword(s):  
Escherichia Coli ◽  
Oral Administration ◽  
Coliform Bacteria ◽  
Escherichia Coli O157 ◽  
Fecal Shedding ◽  
Total Coliforms ◽  
E Coli ◽  
Oral Inoculation ◽  
Experimental Treatments ◽  
And Control

Bacteriophage biocontrol has potential as a means of mitigating the prevalence of Escherichia coli O157:H7 in ruminants. The efficacy of oral administration of bacteriophages for reducing fecal shedding of E. coli O157:H7 by sheep was evaluated using 20 Canadian Arcott rams (50.0 ± 3.0) housed in four rooms (n = 5) in a contained facility. The rams had ad libitum access to drinking water and a pelleted barley-based total mixed ration, delivered once daily. Experimental treatments consisted of administration of E. coli O157:H7 (O157), E. coli O157:H7+bacteriophages (O157+phage), bacteriophages (phage), and control (CON). Oral inoculation of the rams with 109 CFU of a mixture of four nalidixic acid-resistant strains of E. coli O157:H7 was performed on day 0. A mixture of 1010 PFU of bacteriophages P5, P8 and P11 was administered on days -2, -1, 0, 6 and 7. Fecal samples collected on 14 occasions over 21 d were analyzed for E. coli O157:H7, total E. coli, total coliforms and bacteriophages. Sheep in treatment O157+phage shed fewer (P < 0.05) E. coli O157:H7 than did sheep in treatment O157. Populations of total coliforms and total E. coli were similar (P < 0.05) among treatments, implying that bacteriophage lysis of non-target E. coli and coliform bacteria in the gastrointestinal tract did not occur. Bacteriophage numbers declined rapidly over 21 d, which likely reduced the chance of collision between bacteria and bacteriophage. Oral administration of bacteriophages reduced shedding of E. coli O157:H7 by sheep, but a delivery system that would protect bacteriophages during passage through the intestine may increase the effectiveness of this strategy as well as allow phage to be administered in the feed.Key words: Escherichia coli O157:H7, bacteriophage, sheep, environment, coliforms

scholarly journals Early development of cytotoxic T lymphocytes in neonatal foals following oral inoculation with Rhodococcus equi

2011 ◽  
Vol 141 (3-4) ◽  
pp. 312-316 ◽  
Author(s):  
Seth P. Harris ◽  
Melissa T. Hines ◽  
Robert H. Mealey ◽  
Debra C. Alperin ◽  
Stephen A. Hines
Keyword(s):  
T Lymphocytes ◽  
Early Development ◽  
Cytotoxic T Lymphocytes ◽  
Rhodococcus Equi ◽  
Oral Inoculation

scholarly journals Clinical and Microbiological Responses of Volunteers to Combined Intranasal and Oral Inoculation with a Streptococcus gordonii Carrier Strain Intended for Future Use as a Group A Streptococcus Vaccine

2005 ◽  
Vol 73 (4) ◽  
pp. 2360-2366 ◽  
Author(s):  
Karen L. Kotloff ◽  
Steven S. Wasserman ◽  
Kevin F. Jones ◽  
Sofie Livio ◽  
Dennis E. Hruby ◽  
...  
Keyword(s):  
Clinical Trials ◽  
Group A Streptococcus ◽  
Nasal Congestion ◽  
Vaccine Vector ◽  
Mucosal Vaccine ◽  
Respiratory Pathogens ◽  
Streptococcus Gordonii ◽  
Protein Antigens ◽  
Oral Inoculation ◽  
Group A

ABSTRACT Streptococcus gordonii shows promise as a live mucosal vaccine vector for immunization against respiratory pathogens. In preparation for clinical trials to evaluate S. gordonii engineered to express group A streptococcal M protein antigens, we characterized the responses of 150 healthy volunteers to combined nasal and oral inoculation with approximately 1.5 × 109 CFU of SP204(1-1), an S. gordonii strain not bearing vaccine antigens. SP204(1-1) was selected for resistance to streptomycin and 5-fluoro-2-deoxyuridine to distinguish it from indigenous flora. In two antibiotic treatment studies, we performed serial culturing of nose, mouth, and saliva samples from 120 subjects treated with azithromycin beginning 5 days after inoculation to determine whether SP204(1-1) could be rapidly eliminated should safety concerns arise. A natural history study was performed to assess the time until spontaneous eradication in the remaining 30 subjects, who did not receive the antibiotic and who were monitored with repeated culturing for 14 weeks after inoculation. SP204(1-1) was generally well tolerated. Symptoms reported most often within 5 days of inoculation were nasal congestion (36%), headache (30%), and sore throat (19%). The strain was detected by culturing in 98% of subjects. A single dose of azithromycin eliminated colonization in 95% of subjects; all subjects receiving a 5-day course of an antibiotic showed clearance by day 11. Without the antibiotic, 82% of subjects showed spontaneous eradication of the implanted strain within 7 days, and all showed clearance by 35 days. The results of these clinical trials provide encouragement that the use of S. gordonii as a live mucosal vaccine vector is a feasible strategy.

A Comparison of the Survival in Feces and Water of Escherichia coli O157:H7 Grown under Laboratory Conditions or Obtained from Cattle Feces

2006 ◽  
Vol 69 (1) ◽  
pp. 6-11 ◽  
Author(s):  
L. SCOTT ◽  
P. McGEE ◽  
J. J. SHERIDAN ◽  
B. EARLEY ◽  
N. LEONARD
Keyword(s):  
Escherichia Coli ◽  
Foodborne Pathogen ◽  
Hemorrhagic Colitis ◽  
Contaminated Water ◽  
Escherichia Coli O157 ◽  
E Coli ◽  
Cattle Feces ◽  
Oral Inoculation ◽  
Before And After ◽  
Uremic Syndrome

Escherichia coli O157:H7 is an important foodborne pathogen that can cause hemorrhagic colitis and hemolytic uremic syndrome. Cattle feces and fecally contaminated water are important in the transmission of this organism on the farm. In this study, the survival of E. coli O157:H7 in feces and water was compared following passage through the animal digestive tract or preparation in the laboratory. Feces were collected from steers before and after oral inoculation with a marked strain of E. coli O157:H7. Fecal samples collected before cattle inoculation were subsequently inoculated with the marked strain of E. coli O157:H7 prepared in the laboratory. Subsamples were taken from both animal and laboratory-inoculated feces to inoculate 5-liter volumes of water. E. coli O157:H7 in feces survived up to 97 days, and survival was not affected by the method used to prepare the inoculating strain. E. coli O157:H7 survived up to 109 days in water, and the bacteria collected from inoculated cattle were detected up to 10 weeks longer than the laboratory-prepared culture. This study suggests that pathogen survival in low-nutrient conditions may be enhanced by passage through the gastrointestinal tract.

Successful intestinal Echinococcus multilocularis oncosphere invasion and subsequent hepatic metacestode establishment in resistant RccHan™:WIST rats after pharmacological immunosuppression

Parasitology ◽  
2016 ◽  
Vol 143 (10) ◽  
pp. 1252-1260 ◽  
Author(s):  
MARIA TERESA ARMUA-FERNANDEZ ◽  
DEBORAH JOEKEL ◽  
ALEXANDER SCHWEIGER ◽  
RAMON MARC EICHENBERGER ◽  
JUN MATSUMOTO ◽  
...  
Keyword(s):  
T Cell ◽  
Host Resistance ◽  
Echinococcus Multilocularis ◽  
Wistar Rats ◽  
Alveolar Echinococcosis ◽  
Parasite Clearance ◽  
Parasite Invasion ◽  
Oral Inoculation ◽  
Complete Resistance ◽  
Successful Establishment

SUMMARYSusceptibility/resistance to larval Echinococcus multilocularis infection varies greatly depending on host species and strains. Whereas several mice strains and non-human primates are highly susceptible to alveolar echinococcosis, rats and most of humans are considered as more resistant. In this study, we aimed to elucidate factors responsible for host resistance in rats (Experiments A–D). (A) The parasite establishment was not observed in immunocompetent Wistar rats orally inoculated with sodium hypochlorite resistant eggs with/without pig bile, or activated/non-activated oncospheres (NAO). Peritoneal inoculation with NAO or metacestode tissue allowed the parasite establishment in rats. (B) T-cell-deficient athymic nude rats showed complete resistance against the metacestode establishment after oral inoculation with parasite eggs. This finding suggests that T-cell-independent parasite clearance occurred in the animals during early phase of the parasite invasion. Finally, Wistar rats that received pharmacological immunosuppression using either dexamethasone (DMS) alone or methotrexate (MTX) i.p. alone or a combination of these compounds were orally inoculated with the parasite's eggs. As a result (D), successful establishment of metacestode with protoscoleces was observed in all 3 rats treated with DMS (s.c.) alone or in all 6 rats treated with DMS (s.c.) plus MTX but not in 8 rats with MTX alone, suggesting that factors affected by DMS treatment are responsible to regulate the parasite invasion and establishment.

THE OCCURRENCE AND DISTRIBUTION OF SALMONELLA TYPES IN FOWL: II. STUDIES OF ARTIFICIAL S. BAREILLY AND S. ORANIENBURG INFECTIONS IN HENS

1947 ◽  
Vol 25f (6) ◽  
pp. 316-325
Author(s):  
F. E. Chase
Keyword(s):  
Egg Production ◽  
Intestinal Tract ◽  
Experimental Studies ◽  
Similar Nature ◽  
Development Of Resistance ◽  
Oral Inoculation

Experimental studies carried out on a limited number of hens infected orally with S. bareilly indicated that occasionally such hens may lay contaminated eggs. Using the estimated numbers of S. bareilly in the feces as the criterion of infection, considerable variation in susceptibility was evident, the carrier period ranging from 5 to 40 days. The organisms were recovered from the intestinal tract and in one instance from the spleen. The apparent development of resistance to repeated oral inoculation was demonstrated. Experiments of a similar nature were made with hens infected orally with S. oranienburg. No contaminated eggs were found, though in this case low egg production resulting from some of the hens moulting reduces the significance of this finding. Fecal counts were lower than those obtained from the S. bareilly infected hens. S. bonariensis was isolated from the feces of two hens during this experiment.

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