Evaluation of a Serpens species bacterin for treatment of digital dermatitis in dairy cattle.

Digital dermatitis is a major cause of lameness in many dairy herds and represents a detriment to milk production, reproductive efficiency, productive lifespan and welfare. The purpose of this study was to evaluate the therapeutic use of a Serpens species bacterin in a dairy herd known to have a significant prevalence of lameness due to digital dermatitis. Seventy-six mature lactating Holsteins were enrolled in this study. Group 1 (n=38) received three injections of a Serpens species bacterin at four-week intervals (weeks 0, 4, and 8) while group 2 (n=38) received only adjuvant. Blood samples were obtained prior to the first injection at week 0 and again at week 12 to evaluate antibody responses. Locomotion and digital dermatitis lesion measurements were performed at weeks 0, 12 and 18. Although Serpens-associated antibody titers increased from week 0 to 12 in vaccinated cows; the prevalence of digital dermatitis, the percentage of cows identified as clinically lame and the average width of digital dermatitis lesions did not differ from week 0 to 12 or from week 0 to 18 between groups. The results of this study indicate a lack of any clinical efficacy associated with vaccination in this herd, although inoculation with the bacterin did stimulate a measurable antibody response.

Biological activity of lipopolysaccharides from oral Selenomonas.

Lipopolysaccharides (LPSs) were extracted by phenol-water from three oral strains of Selenomonas. The preparations were tested for the ability to induce a blastogenic response in cultures of spleen cells from normal and nude BALB/c mice, to activate guinea pig complement and the clotting enzyme system of Limulus polyphemus amoebocytes, and to kill Actinomycin-D treated mice. The capacity of the three LPSs was comparable to that of enterobacterial LPS.

Phosphate-starvation-induced outer membrane proteins of members of the families Enterobacteriaceae and Pseudomonodaceae: demonstration of immunological cross-reactivity with an antiserum specific for porin protein P of Pseudomonas aeruginosa.

Bacteria from members of the families Enterobacteriaceae and Pseudomonadaceae were grown under phosphate-deficient (0.1 to 0.2 mM Pi) conditions and examined for the production of novel membrane proteins. Of the 17 strains examined, 12 expressed a phosphate-starvation-induced outer membrane protein which was heat modifiable in that after solubilization in sodium dodecyl sulfate at low temperature the protein ran on gels as a diffuse band of higher apparent molecular weight, presumably an oligomer form, which shifted to an apparent monomer form after solubilization at high temperature. These proteins fell into two classes based on their monomer molecular weights and the detergent conditions required to release the proteins from the peptidoglycan. The first class, expressed by species of the Pseudomonas fluorescens branch of the family Pseudomonadaceae, was similar to the phosphate-starvation-inducible, channel-forming protein P of Pseudomonas aeruginosa. The second class resembled the major enterobacterial porin proteins and the phosphate-regulated PhoE protein of Escherichia coli. Using a protein P-trimer-specific polyclonal antiserum, we were able to demonstrate cross-reactivity of the oligomeric forms of both classes of these proteins on Western blots. However, this antiserum did not react with the monomeric forms of any of these proteins, including protein P monomers. With a protein P-monomer-specific antiserum, no reactivity was seen with any of the phosphate-starvation-inducible membrane proteins (in either oligomeric or monomeric form), with the exception of protein P monomers. These results suggest the presence of conserved antigenic determinants only in the native, functional proteins.

Common lipopolysaccharide specificity: new type of antigen residing in the inner core region of S- and R-form lipopolysaccharides from different families of gram-negative bacteria.

A new antigenic specificity, referred to here as common lipopolysaccharide (LPS) specificity, is described in the LPSs of gram-negative bacteria belonging to various families. The specificity is present in S- and R-form LPS but absent in Re mutants of different enterobacterial genera. By the use of purified LPS and monospecific antibodies obtained by immunoabsorption, the specificity is differentiated from the known core specificities of the genus Salmonella and the lipid A specificity by aid of the passive hemolysis and passive hemolysis inhibition test. In Salmonella minnesota R-form LPS, the specificity may be cryptic (R345, Rb2 mutant) or partly exposed in the intact molecule (R7, Rd1 mutant). The specificity is either demasked or completely exposed after mild acid hydrolysis for a short time, whereas it is destroyed after prolonged hydrolysis. Periodate oxidation, reduction, and hydrolysis under conditions that do not affect the ketosidic linkages of 2-keto-3-deoxyoctulosonic acid destroy the specificity in R4 (Rd2 mutant) LPS, but do not do so in R7 LPS. It is suggested that 2-keto-3-deoxyoctulosonic acid and a following neutral sugar are the compositional requirements for expressing the specificity.

Application of the fluorescent antibody technique to the study of an isolate of Beijerinckia in soil.

Fluorescent antibody was prepared against a temperate-soil isolate of Beijerinckia obtained from a rhizosphere of rice growing in Camargue (France). The antibody did not cross-react with any of 6 species of Azotobacter, 4 species of Beijerinckia, or 44 unidentified soil bacteria isolated from a spectrum of rhizospheres, but strongly stained the homologous Beijerinckia isolate. The isolate grew well in autoclave Camargue soil, but increased in numbers only slightly in nonsterile soil during 9 days. Preliminary examination of rice plants grown in the laboratory in soil from which the Beijerinckia was originally isolated did not show detectable Beijerinckia in the rhizosphere. The fluorescent antibody was sufficiently sensitive and specific to permit more extensive study of Beijerinckia in relation to nitrogen fixation in the rhizospher of rice.

"Core" glycolipid of enterobacteriaceae: immunofluorescent detection of antigen and antibody.

The Re chemotype mutant of Salmonella minnesota R595 has a cell-wall glycolipid composed principally of 2-keto, 3 deoxyoctonate and Lipid A, which is an antigen widely shared by Enterobacteriaceae. High-titered antiserum against this antigen can be conjugated with fluorescein isothiocyanate for direct detection of this antigen in heterologous bacteria and staining of bacteria in tissue. Alternatively, the indirect immunofluorescence technique can be used for antigen detection on bacterial surfaces and in tissues, and this method can quantitate glycolipid antibody in mammalian sera. The latter may be particularly useful in serologic studies because, although the glycolipid antigen is a surface antigen and purified extracts can be used to coat latex particles, high-titered antisera will not agglutinate bacteria or coated latex particles.