Selektive Anreicherung von Staphylokokken-Panton-Valentine-Leukozidin mit Aluminiumoxid-Cholesterin / Selective Enrichment of Staphylococcus “Panton-Valentine”-Leukocidine with Aluminium Oxide Cholesterol

A selective concentration of “Panton-Valentine”-leukozidine (PVL) from the culture-supernatant Staphylococcus aureus was achieved through adsorption of most of the a-hemolysin, coagulase, eggyolk-opacity factor and fibrinolysin to aluminiumoxide cholesterol. PVL was further concentrated through dialysis against a saturated ammonium sulfate solution and subsequent pressure-filtration. Through pressure-filtration relatively low-molecular staphylococcal substances, such as a part of a nuclease, could be separated from PVL.

Effects of the collagenolytic cell wall component of Fusobacterium necrophorum subsp. necrophorum on bovine hepatocytes

The effects of the collagenolytic cell wall component (CCWC) of Fusobacterium necrophorum subsp. necrophorum on bovine hepatic cell and cytoskeletons were investigated. Scanning electron microscopy (SEM) demonstrated that CCWC damaged the cell surfaces, forming tiny holes on the cell membranes. Sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE) profiles revealed that CCWC degraded bovine cytokeratin and vimentin and by indirect fluorescent antibody (IFA) method, it was shown that CCWC caused the deformation of hepatocellular vimentin. This suggested that CCWC contributes to bovine hepatic injury and it may be as important pathogenic factor in the development of bovine hepatic abscesses.

Attempts to separate female Ascaris suum antigen and to investigate its partial characterization

The location and separation of Ascaris suum antigen for serological testing was investigated. The antigenic constituent was rich in the ovary of the adult worm and was obtained by dialysis with 50% ammonium sulphate saturated solution. Sodium dodecyl sulphate polyacrylamide gel electrophoresis and immunoblotting analysis demonstrated that the heat labile antigenic preparation showed one major and seven faint bands. The major band seemed also to be a glycoprotein. The sera from pigs with/without hepatic milk spot showed relatively high precipitation titres, while, those from the specific pathogen free pigs manifested low titres.

Collagenolytic activity of a cell wall preparation from Fusobacterium necrophorum subsp. necrophorum

A collagenolytic preparation of Fusobacterium necrophorum subsp. necrophorum was derived from the bacterial cell. It was further treated for gel permeation with Toyopearl HW 50, followed by Sepharose 4B column chromatography. In sodium dodecyl sulphate polyacrylamide gel electrophoresis, the final preparation exhibited one definite band and at least one faint band. It was inactivated completely by adjusting the pH to 4.0 or by heating at 80 degrees C for 30 min.

Effects of Fusobacterium necrophorum subspecies necrophorum on extracellular matrix of tissue-cultured bovine kidney cells

The effects of Fusobacterium necrophorum subsp. necrophorum on the extracellular matrix were investigated. The toxic preparation from the culture induced reduction in the number of tissue-cultured bovine kidney cells. The exposed cells often manifested partial loss of cytoplasm and were morphologically irregular. Scanning electron microscopy demonstrated partial loss of the microvilli on the exposed cells and roughness of the cell surfaces. Finally, sodium dodecyl sulphate polyacrylamide gel electrophoresis profiles revealed complete degradation of bovine collagen type 1 after treatment with the toxic preparation. This degradation was inhibited by the addition of homologous antiserum. These findings indicate that the degradation may contribute to the establishment of the infection caused by F.n. subsp. necrophorum.

Adherence of Fusobacterium necrophorum subsp. necrophorum to ruminal cells derived from bovine rumenitis

Fusobacterium necrophorum subsp. necrophorum strain VPI 2891 was shown to adhere to the surfaces of ruminal cells derived from bovine rumenitis. The strain also attached to bovine type 1 collagen. Treatment of the bacterium with antiserum to bacterial cells reduced attachment. The bacterial attachment was also markedly reduced when the ruminal cells had been pretreated with anticollagen serum. Fluorescence specific for the collagen was demonstrated on the surface of bovine tissue affected with rumenitis. These findings suggest that F. necrophorum subsp. necrophorum strain VPI 2891 adheres to the ruminal cells derived from rumenitis tissue and that the attachment may be mediated by cellular collagen.

Actin degradation concomitant with Fusobacterium necrophorum subsp. necrophorum adhesion to bovine portal cells

The effects of Fusobacterium necrophorum subsp. necrophorum on cellular actin were investigated using tissue-cultured bovine portal cells. Fluorescence studies revealed the appearance of intense fluorescent spots on the cellular actin and the spots increased in a time dependent manner. Sodium dodecyl sulphate polyacrylamide gel electrophoresis profiles manifested partial or complete degradation of actin preparation after treatment with the bacterial cells. These findings suggest that the bacterial cell wall may contribute to the degradation of the cellular actin during the initial stage of the infection caused by F. necrophorum subsp. necrophorum.

Fusobacterium necrophorum haemolysin stimulates motility of ileal longitudinal smooth muscle of the guinea-pig

Fusobacterium necrophorum haemolysin (0.5-3.1 mg protein/mL) dose-dependently induced contractions of the isolated ileal longitudinal smooth muscle of the guinea-pig. The haemolysin (3.1 mg protein/mL) -induced maximum contraction of 75% of the response to 60 mM K+ declined within 17 min and the muscles then demonstrated rhythmic contractions. Tetrodotoxin (3.1 x 10(-6) M) had no effect on the contraction due to the haemolysin. After incubation in Ca(2+)-free medium, the ileal response to the haemolysin was lost. Verapamil, a Ca2+ channel blocker, dose-dependently inhibited the contraction to the haemolysin. The rabbit anti-serum against F. necrophorum haemolysin inhibited the haemolysin-induced contraction of ileal muscle. The bacterial haemagglutinin and the lipopolysaccharide had no effect on the response of ileal muscle. These findings suggest that the haemolysin-induced direct stimulation of ileal motility dependant on Ca2+ influx will increase the probability of contact of F. necrophorum and ileal mucosa and could increase the chances of colonization for F. necrophorum.

Adherence of Fusobacterium necrophorum subspecies necrophorum to different animal cells

The adherence of Fusobacterium necrophorum subsp. necrophorum to the surfaces of animal cells was studied in order to elucidate the differences between the bacterial appearance in clinical specimens from various animals. The bacterial cells had a strong affinity for murine and rabbit cheek cell surfaces. The bacterium showed a moderate affinity for goat cells, whereas it adhered not so well to canine, feline, human or porcine cells. Treatment of the bacterial cells with haemagglutinin antiserum prior to the binding assay reduced the degree of attachment to murine and rabbit cells. Scanning electron microscopy revealed that the adherent fusobacteria often penetrated into murine and rabbit cell membranes. These observations indicate that the bacterial attachment contributes to the establishment of the infection in mice and rabbits. It is suggested that the weak binding ability resulted in a low incidence of the bacterium in canine, feline and porcine lesions.

Location of haemagglutinin in bacterial cells of Fusobacterium necrophorum subsp. necrophorum

The location of haemagglutinin (HA) of Fusobacterium necrophorum subsp. necrophorum VPI 2891 strain was investigated by immunofluorescence, confocal laser scan microscopy and immunoelectron microscopy. The immunofluorescence study demonstrated the fluorescence specific for the HA on the bacterial cells and confocal laser scan microscopy indicated similar fluorescence around the cross section of the bacterial cell. The immunoelectron microscopic study also revealed that the protein A-gold conjugates were located around the bacterial surfaces. These findings suggest that HA is one of the components of the cell surfaces of F. necrophorum subsp, necrophorum.

Detection of cytotoxic effects of Clostridium novyi type A on bovine kidney cells

The cytotoxic effects of a toxic preparation from Clostridium novyi type A were demonstrated on tissue-cultured bovine kidney cells. The cytotoxic response was dose-dependent and could be neutralized by homologous antiserum. Scanning electron microscopy revealed damaged kidney cell surfaces. These findings indicated that the cytotoxicity may contribute to the formation of the foci in bovine tissue during an infection with C. novyi.

Cloning and sequencing of the genome of chicken anaemia virus (CAV) TK-5803 strain and comparison with other CAV strains

The complete genomic sequence of chicken anaemia virus (CAV) TK-5803 strain was determined. Comparisons of sequence data showed 37 nucleotide differences between TK-5803 and Cux-1, 38 nucleotide differences between TK-5803 and 26P4, and 48 nucleotide differences between TK-5803 and 82-2. There were 65 nucleotide differences in the largest open reading frame (ORF3) between TK-5803 and one Australian isolate. Base changes introduced amino acid changes at 6 positions in the C-terminal half of VP3, at 4 positions in the C-terminal quarter of VP2 and at 17 positions in VP1 among the strains. These indicate that the N-terminal half of VP3 and the N-terminal three quarter of VP2 are well conserved, and might sustain essential function of these proteins. The amino acid changes in VP1 which is thought to be the capsid protein may influence the antigenic character of different VP1s.

Factors affecting induction of neurological disorders in mice by paralysis-inducing Friend-related PVC viruses

Our previous studies showed that the passage of the Friend virus complex through rats generated variant MuLVs, designated PVC111, PVC211, PVC321 and PVC441, that induced neurological disorders associated with tremor and paralysis. In this study, we tested the pathogenicity of four different PVC viruses in mice. Although histopathological studies revealed spongiform degeneration in the spinal cords of NFS mice infected with each PVC virus, only PVC441 frequently induced tremor and paralysis. After a long latency, all of these viruses induced leukemia associated with severe anemia. Further studies with PVC441 revealed dose- and age-dependence for tremor induction. In contrast to NFS mice, BALB/c, DBA/2 and C57BL/6 mice infected with PVC441 virus showed no neurological symptoms, although the virus could be isolated from the tissues of central nervous system. Despite the absence of neurological symptoms, a high degree of neuronal degeneration in the lumbar spinal cord was found in PVC441-infected BALB/c mice. A low degree of neuronal degeneration was found in PVC441-infected DBA/2 or C57BL/6 mice. Genetic crosses of these resistant mice with susceptible NFS mice indicated that resistance to tremor induction by PVC441 was dominant in all mouse strains and suggested that various host genes may control the susceptibility of mice to tremor induction by PVC441 virus.

Isolation of obligate and facultative anaerobic bacteria from feline subcutaneous abscesses

A total of 113 specimens collected from purulent skin lesions of household cats was examined bacteriologically. Ninety seven isolates obtained from 74 specimens (65.5%). Of these, 11 specimens (9.7%) contained obligate anaerobes only, 18 specimens (15.9%) yielded both obligate and facultative anaerobes. In the obligate anaerobes detected, genus Fusobacterium was the most frequently observed and F. nucleatum was most common species. Pasteurella multocida was the facultative anaerobe which was most frequently detected.

Use of enzyme-linked-immunosorbent assay for detection of IgG and IgM antibodies to Fusobacterium necrophorum in cattle

An enzyme-linked-immunosorbent assay (ELISA) with HCl heat-extracted antigen of Fusobacterium necrophorum was conducted to detect specific immunoglobulins G and M in infected cattle. The ELISA revealed an increase (> 0.40) in specific IgG in most of the animals with hepatic abscesses but not that in specific IgM. All the lesions were positive for F. necrophorum. These findings indicated that the ELISA for immunoglobulin G detection may prove to be a useful tool for predictive serodiagnosis of F. necrophorum infection in cattle.

Biphasic immune responses of cats under controlled infection with a feline enteric coronavirus-79-1683 strain

Kittens inoculated orally with 10(2) PFU of feline enteric coronavirus developed no antibody to the virus despite the repeated challenges. However, they developed antibody for a long period with 5 x 10(3)-1.6 x 10(5) (mean 3 x 10(4)) and with 2.5 x 10(3)-2 x 10(4) (mean 6 x 10(3)) immunoperoxidase antibody titer when they were challenged with 10(5) and 10(3) PFU of virus following previous challenges, respectively. Viremia was found when kittens were inoculated with 10(5) PFU of virus, but not with 10(3) PFU of virus. The dose of 10(3) PFU of virus seemed to be a lower limit to establish infection. These results indicate that local infection induces a low antibody response and systemic infection induces a high antibody response.

Dermonecrotic activity of a cell wall preparation from Fusobacterium necrophorum

A cell wall preparation of Fusobacterium necrophorum induced haemorrhagic necrosis in the skins of guinea pigs and rabbits. Effects in mice and rats were weak or absent. The toxic activity of the cell wall preparation was not reduced by heat treatment. A dermonecrotic toxin was isolated from the cell wall preparation with sodium dodecylsulphate and concentrated by precipitation with ethanol. A preparation of the bacterial cytoplasm from Fus. necrophorum induced mainly erythema.

Ultrastructure and cytochemical characteristics of leukocyte infected with Hepatozoon canis

We have observed the ultrastructure of a canine leukocyte infected with Hepatozoon canis by transmission electron microscope. The infected leukocytes contained many small vesicles and a few typical granules in the cytoplasm. They also contained a few rough surfaced endoplasmic reticula, mitochondria and a segmented nucleus with condensed chromatin. Cytochemical analysis indicated that the infected leukocytes with H. canis contained little alkaline phosphatase, peroxidase, naphthol AS-D chloroacetate esterase or alpha naphthol acetate esterase. These results suggested that the infected leukocytes were neutrophils or monocytes which lost their typical characteristics.

Seasonal periodical appearance of Hepatozoon canis gamont in the peripheral blood

We investigated the appearance of gamonts in peripheral leukocytes of 13 Hepatozoon canis infected dogs from June 1990 to December 1992. In almost all the dogs, the numbers of gamonts increased from spring to autumn, and decreased from autumn to winter. Particularly in the dogs used for hare hunting, a large number of gamonts was detected from spring to autumn. This finding reveals that the gamont increases in number in the dog which ingested the infected ticks during the hunting season.

Humoral immune responses of cats to feline infectious peritonitis virus infection

Immunoperoxidase antibody (IPA) method as a titrating method of feline infectious peritonitis (FIP) virus (FIPV) was developed for titrating antibody to FIPV (IPA-titer). By this method the immune responses of the cats that had been infected with FIPV, were traced. The infected cats could be grouped into three types by their immune response to FIPV and clinical appearances. Type I cats lived for a long time, formed a major group among infected cats, had 160 to 1 x 10(4) IPA-titers, and showed healthy appearances without any changes both on autopsy and histopathologically. From among type I cats, type II cats appeared sporadically with rapid elevation of IPA titers to 3.2 x 10(5) and showing clinical signs of FIP, and died. Type III cats lived healthily for a long time with gradual elevation of IPA-titers to a plateau of about 1 x 10(5), then showed neuronal disorder of hind leg paralysis with the descending IPA-titers to 2 x 10(4), and died. Thus, typical FIP appeared as a hyper-immune disease. Other related problems are discussed.

Fusobacterium necrophorum hemolysin in bovine hepatic abscess

An immunofluorescence study was made on bovine hepatic abscess containing Fusobacterium necrophorum predominantly. The abscess section stained with anti F. necrophorum hemolysin serum demonstrated fluorescence which formed irregular and granular shapes. Actinomyces pyogenes isolates from the abscess were not stained with the serum. These findings suggest that the bacterial hemolysin contributes to the formation of the hepatic abscess during an infection with F. necrophorum.

Leukotoxic activity of Clostridium perfringens of equine origin

Leukotoxic activity of equine isolates of Clostridium perfringens type A was examined. Thirty-seven isolates (94.9%) of 39 isolates demonstrated leukotoxic effects on mouse peritoneal macrophages. Phase contrast microscopy revealed that the toxic preparations induced rounded protoplasmic extrusion and sometimes destruction of the cells, leaving some membrane fragments. These findings suggest that the leukotoxic activity could be considered to be a virulence factor of C. perfringens.

Bovine platelet aggregation by Fusobacterium necrophorum

Fusobacterium necrophorum aggregated bovine platelets. The aggregation was paralleled by the haemagglutinating ability of the organism. Treatment of the bacterial cells with antiserum to the homologous purified haemagglutinin reduced the degree of platelet aggregation. Scanning electronmicroscopy revealed that little lysis of the affected platelets occurred during the 1-h incubation period. Purified haemagglutinin became bound to the surfaces of the platelet cells as shown by immunofluorescence microscopy. These observations suggest that platelet aggregation is mediated by the haemagglutinin and may be related to the pathogenicity of the bacterium.

Effects of Fusobacterium necrophorum on the mesenteric microcirculation of guinea pigs

Thrombi formation was demonstrated in mesenteric microcirculation of guinea pigs inoculated with Fusobacterium necrophorum and the bacterial hemagglutinin (HA). The thrombi were initially observed in venules and later, in arterioles. Immunofluorescence study revealed that the HA bound to the thrombi in the microcirculation. These results indicate that thrombosis is an early step in the pathogenesis of necrosis.

Effects of leukocidin from Fusobacterium necrophorum on bovine peripheral leukocytes in vitro

Partially purified leukocidin from Fusobacterium necrophorum damaged bovine peripheral leukocytes as demonstrated by trypan blue staining. Granulocytes were most and T-lymphocytes least sensitive to the leukocidin. Heating for 30 min at 60 degrees C completely inactivated the leukocidin. The cytotoxicity of the leukocidin could be neutralized by homologous anti-leukocidin. Scanning electron microscopy of the exposed cells revealed an apparent destruction of the cell membranes, loss of the microvilli and smoothing of the cell surfaces.

Cytotoxic effects of a leukocidin from Fusobacterium necrophorum on bovine hepatic cells

Cytotoxic effects of a leukocidin from Fusobacterium necrophorum were demonstrated on bovine hepatic cells. The cytotoxic response was dose-dependent and could be inhibited by homologous antiserum. Scanning electron microscopy revealed damaged hepatic cell surface. These findings indicated a pathogenic role of the leukocidin in F. necrophorum infections.

Adherence of Fusobacterium necrophorum to bovine ruminal cells

The adherence of Fusobacterium necrophorum to the surface of bovine ruminal epithelial cells was paralleled by the organism's haemagglutinating ability. Treatment of the bacterial cells with haemagglutinin antiserum caused a reduction in the degree of attachment. The purified haemagglutinin became bound to the membranes of ruminal epithelial cells but lost its adherence when pre-incubated with haemagglutinin antiserum. These findings suggest that the adherence of F. necrophorum to the membrane of the ruminal cells is mediated by haemagglutinin.

Partial characterization of leukocidin from Fusobacterium necrophorum

Leukocidin from Fusobacterium necrophorum was produced in the diffusate of a dialysis culture. It was free from deoxyribonuclease, fibrinolysin, gelatinase, haemolysin, lipase, caseinase and endotoxin. The leukocidin had a molecular weight between 10,000 and 5,000 as estimated by membrane partition chromatography. It formed precipitin lines with anti-leukocidin-serum in double immunodiffusion tests. Mouse peritoneal cells were characteristically damaged by the leukocidin, as revealed by scanning electron microscopy. The damaged cells lost microvilli and suffered partial destruction of their cell membranes.

Adherence of Fusobacterium necrophorum to Vero cells

The adherence of the anaerobic species Fusobacterium necrophorum to the surface of Vero cells was studied. Adherence between the bacterium and the tissue culture cells was paralleled by the hemagglutinability of F. necrophorum. Treatment of the bacterial cells with lactoalbumin hydrolysate or anti-F. necrophorum-hemagglutinin serum reduced the intensity of the attachment. The purified hemagglutinin bound to the membranes of Vero cells. It lost its adherent property when mixed with the homologous anti-hemagglutinin serum. These observations suggest that the adherence of F. necrophorum to the surface of Vero cells is mediated by the bacterial hemagglutinin.

Isolation of obligate anaerobic bacteria from bovine abscesses in sites other than the liver

A survey in Japan showed that of 2036 slaughtered cattle 58(3%) had abscesses in sites other than the liver. In 21 of the affected animals the lesions were pulmonary and in 32 abdominal (excluding hepatic); in five animals the lesions were found elsewhere (muscle 2, skin 2, bone 1). Nineteen (33%) of the 58 cattle also had abscesses in the liver. Obligate anaerobes alone were isolated from 17(29%) of the affected animals (Fusobacterium necrophorum 14, Bacteroides spp. 2, Peptostreptococcus anaerobius 1). A mixture of obligate anaerobes and aerobes or facultative anaerobes was isolated from 31 affected cattle: of these animals 21 yielded large and five small numbers of F. necrophorum; three yield fusobacteria other than F. necrophorum; and two yielded Propionibacterium acnes. The remaining 10 affected animals yielded only aerobes or facultative anaerobes. The numbers of viable obligate anaerobes in pus specimens were in the range 10(3)-10(9)/ml.

Purification and partial characterization of Fusobacterium necrophorum hemagglutinin

Hemagglutinin (HAin) of Fusobacterium necrophorum was separated from the bacterial cells by trypsinization-sonication, and purified by the gel filtration on Sephadex G-100 column. The final product obtained from gel filtration gave one precipitin line in the immunodiffusion gel and produced a single band in polyacrylamide gel electrophoresis. The molecular weight of the HAin was estimated to be about 19000 by sodium dodecyl sulfate polyacrylamide gel electrophoresis. It was heat labile and comparatively rich in alanine, glutamine and histidine. Electron microscopy observation revealed that the HAin was a filamentous rod with 0.5-1.0 nm width or frequently showed a cluster form. The hemagglutinability was inhibited by addition of albumins but not by sugars and lipopolysaccharide. Anti HAin rabbit serum inhibited hemagglutination.

Effects of Panton-Valentine Leukocidin of Staphylococcus aureus on Leukocytes from Patients with Leukemia

Mature granulocytes from six patients with myelocytic leukemia and monocytic cells from two patients with monocytic leukemia were damaged after incubation with leukocidin from Staphylococcus aureus. The immature granulocytes were not significantly affected. The lymphocytic cells from one patient with lymphocytic leukemia were not markedly damaged. The numbers of erythrocytes from all nine patients remained practically unchanged with lower concentrations of leukocidin.