Evaluation of experimentally induced Fusobacterium necrophorum infections in mice

Conlon, Paul; Hepper, K P; Teresa, G. W.

doi:10.1128/iai.15.2.510-517.1977

Cited by 13 publications

(2 citation statements)

References 24 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Several investigators have attempted to induce protective immunity against F. necrophorum by using a variety of antigenic components. Attempts to induce protective immunity have included the use of whole-cell cultures (Roberts, 1970;Abe et al, 1976a;Cameron and Fuls, 1977;Conlon et al, 1977;Smith et al, 1985Smith et al, , 1989, cytoplasmic fractions (Garcia et al, 1974(Garcia et al, , 1975aGarcia and McKay, 1978), lipopolysaccharides (Garcia et al, 1974(Garcia et al, , 1975aAbe et al, 1976a;Cameron and Fuls, 1977;Conlon et al, 1977;Smith et al, 1985Smith et al, , 1989, outer membrane proteins (Emery and Vaughn, 1986), leukotoxins (Roberts, 1970;Garcia et al, 1975a;Clarke et al, 1986;Emery et al, 1986a,b;Saginala et al, 1996a,b), and culture supernatants (Jensen et al, 1954c;Takeuchi et al, 1984;Saginala et al, 1996aSaginala et al, ,b, 1997. Efficacy has varied from nil to significant protection.…”

Section: Itemmentioning

confidence: 99%

Liver abscesses in feedlot cattle: a review.

Nagaraja

Chengappa

1998

Journal of Animal Science

333

194

View full text Add to dashboard Cite

Liver abscesses in slaughtered beef cattle result from aggressive grain-feeding programs. The incidence, averaging from 12 to 32% in most feedlots, is influenced by a number of dietary and management factors. Liver abscesses represent a major economic liability to producers, packers, and ultimately consumers. Besides liver condemnation, economic impacts include reduced feed intake, reduced weight gain, decreased feed efficiency, and decreased carcass yield. Fusobacterium necrophorum, a member of the ruminal anaerobic bacterial flora, is the primary etiologic agent. Actinomyces pyogenes is the second most frequently isolated pathogen. Ruminal lesions resulting from acidosis generally are accepted as the predisposing factors for liver abscesses. F. necrophorum possesses or produces a number of virulence factors that participate in the penetration and colonization of the ruminal epithelium and subsequent entry and establishment of infection in the liver. However, only a few virulence factors have been characterized well. Control of liver abscesses in feedlot cattle generally has depended on the use of antimicrobial compounds. Five antibiotics (i.e., bacitracin methylene disalicylate, chlortetracycline, oxytetracycline, tylosin, and virginiamycin) are approved for prevention of liver abscesses in feedlot cattle. Tylosin is the most effective and the most commonly used feed additive. Tylosin feeding reduces abscess incidence by 40 to 70%. The mode of action of antibiotics in preventing liver abscesses is believed to be via inhibition of ruminal F. necrophorum. Protective immunity against F. necrophorum induced by a variety of antigenic components has ranged from ineffectual to significant protection.

show abstract

Section: Itemmentioning

confidence: 99%

Liver abscesses in feedlot cattle: a review.

Nagaraja

Chengappa

1998

Journal of Animal Science

333

194

View full text Add to dashboard Cite

show abstract

“…necrophorum type B strains has been reported to be 5 x 106 CFU per mouse (WENZEL et al 1983)) considerably lower than that obtained with a, human type A strain. I n studies using a bovine strain of Fusobacterium, CONLON et al (1977) found a dose of 4 x lo6 was necessary to produce abscesses in liver, kidney and spleen. Mice were protected from abscess formation when they were pretreated with lipopolysaccharide isolated from the homologous bacterial strain.…”

Section: Discussionmentioning

confidence: 99%

Studies on bacterial synergism in mice infected with Bacteroides intermedius and Fusobacterium necrophorum

Price

McCallum

1987

J. Basic Microbiol.

View full text Add to dashboard Cite

This study was undertaken to characterize the kinetics of possible bacterial synergy using a mouse model of mixed intraabdominal infection with Bacteroides intermedius and Fusobacterium necrophorum. Female CD-1 mice were injected intraperitoneally with B. intermedius, F. necrophorum or mixtures of both organisms. Generalized septic peritonitis developed within 24 hr, with abscess formation occurring after one to two wk in survivors with the mixed infection. Involvement of the reticuloendothelial system was evidenced by dose-dependent hepatosplenomegaly, which appeared during the first wk postinfection and progressed throughout the course of the experiment. Indirect immunofluorescence confirmed the presence of both species of bacteria in frozen sections of liver tissue. The median lethal dose (LD50) was 2.11 x 10(9) for the mixture, 3.03 X 10(9) for B. intermedius alone, and 1.07 X 10(9) for F. necrophorum alone. The median abscess-producing dose (AD50), the dose required to produce abscesses in fifty percent of the surviving mice at two wk, was approx. 1/100 of the LD50 dose. The AD50 for intrahepatic abscesses was 2.8 x 10(8) for the mixture, whereas the AD50 for intraabdominal abscesses occurring in any site was 5.14 X 10(7). Both Bacteroides and Fusobacterium persisted in tissue for at least 22 wk following mixed infection. The persistence of the Bacteroides in tissue represents a synergistic result of mixed infection with Fusobacterium and contributed to the chronicity of intraabdominal abscess formation. Bacteroides, injected alone, did not produce abscesses at any of the doses tested. However, when passaged (isolated from mixed infection hepatic abscesses) B. intermedius was used, the bacteria did induce abscesses.

show abstract

Fusobacterium necrophorum infections: Virulence factors, pathogenic mechanism and control measures

1996

View full text Add to dashboard Cite

Fusobacterium necrophorum, a Gram-negative, non-spore-forming anaerobe, is a normal inhabitant of the alimentary tract of animals and humans. Two types of F. necrophorum, subspecies necrophorum (biotype A) and funduliforme (biotype B), have been recognized, which differ morphologically, biochemically, and biologically. The organism is an opportunistic pathogen that causes numerous necrotic conditions (necrobacillosis) such as bovine hepatic abscesses, ruminant foot abscesses and human oral infections. The pathogenic mechanism of F. necrophorum is complex and not well defined. Several toxins, such as leukotoxin, endotoxin, haemolysin, haemagglutinin and adhesin, have been implicated as virulence factors. Among these, leukotoxin and endotoxin are believed to be more important than other toxins in overcoming the host's defence mechanisms to establish the infection. F. necrophorum is encountered frequently in mixed infections and, therefore, synergisms between F. necrophorum and other pathogens may play an important role in infection. Several investigators have attempted to induce protective immunity against F. necrophorum using bacterins, toxoids, and other cytoplasmic components. Generally, none of the immunogens has afforded satisfactory protection against Fusobacterium infections. Because of the unavailability of suitable immunoprophylaxis, the control of F. necrophorum infection has depended mainly on the use of antimicrobial compounds.

show abstract

Evaluation of experimentally induced Fusobacterium necrophorum infections in mice

Cited by 13 publications

References 24 publications

Liver abscesses in feedlot cattle: a review.

Liver abscesses in feedlot cattle: a review.

Studies on bacterial synergism in mice infected with Bacteroides intermedius and Fusobacterium necrophorum

Fusobacterium necrophorum infections: Virulence factors, pathogenic mechanism and control measures

Contact Info

Product

Resources

About