6 research outputs found
Antibiotic susceptibility of Fusobacterium necrophorum isolated from liver abscesses
Antibiotic susceptibility patterns of thirty-seven isolates of Fusobacterium necrophorum (21 biotype A and 16 biotype B) from liver abscesses of feedlot cattle were determined. These isolates were generally susceptible to penicillins, tetracyclines (chlortetracycline and oxytetracycline), lincosamides (clindamycin and lincomycin), and macrolides (tylosin and erythromycin) but resistant to aminoglycosides (kanamycin, neomycin, gentamycin and streptomycin), ionophores(except narasin), and peptides (avoparcin, polymixin, and thiopeptin). Differences in antibiotic sensitivity patterns were observed between the two biotypes
only for clindamycin and lincomycin. The minimum inhibitory concentrations (MIC) of
FDA-approved antibiotics for liver abscess control did not parallel their efficacy in preventing clinical liver abscesses in feedlot cattle. Continuous tylosin feeding did not appear to induce antibiotic resistance in F.necrophorum
Experimental induction and monitoring of liver abscesses in cattle with ultrasonography
We have demonstrated that ultrasonography can be used to visualize liver
abscess in live cattle. We have also developed a nonsurgical method of catheterizing
the bovine portal vein and experimentally inducing liver abscesses by inoculating the
portal vein with Fusobacterium necrophorum bacteria
Bacteriological and histopathological investigations of liver abscesses
Fusobacterium necrophorum was the predominant bacterial isolate from 49
liver abscesses. Biotype A tended to occur in pure infections and produced a more
severe tissue reaction than biotype B, which tended to occur as a mixed infection
Fusobacterium necrophorum leukotoxoid vaccine for prevention of liver abscesses
The efficacy of Fusobacterium
necrophorum crude leukotoxoid vaccine to
immunize and protect steers against experimentally
induced liver abscesses was evaluated.
The vaccine consisted of cell-free
culture supernatant of a high leukotoxin-producing
strain of F. necrophorum, inactivated
with formalin and homogenized with an
oil emulsion adjuvant. Vaccine was injected
subcutaneously on days 0 and 21. Blood
samples were collected weekly to monitor
immune response. Three weeks after the
second vaccination, steers were injected
intraportally with F. necrophorum culture to
induce liver abscesses. Three weeks later (day
63), steers were euthanatized and necropsied;
livers were examined, and protection was
assessed. Anti-leukotoxin antibody titers in
the control steers generally did not differ
from the baseline (week 0) titers. The titers
in the vaccinated groups increased, more so
after the second injection, and the increase
was generally dose dependent. At necropsy,
all steers in the control group had liver
abscesses. In the vaccinated groups, two out
of five steers in the 1.0 ml group and one
each in the 2.0, 5.0, and 2.25 ml (concentrated)
groups had liver abscesses. The difference
suggests a protective effect of antileukotoxin antibodies against experimentally
induced liver abscesses
An immunochromatographic serological assay for the diagnosis of Mycobacterium tuberculosis
10.1016/S0147-9571(01)00016-9Comparative Immunology, Microbiology and Infectious Diseases25121-27CIMI