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M Plommet

Publications and source records attributed to M Plommet.

At least 37 records · Page 2Linked to original sources
PubMed1983

Immune serum-mediated effects on brucellosis evolution in mice.

Immune serum injected into mice before a footpad challenge of virulent strain Brucella abortus 544 can prevent dissemination of infection to the spleen. Sera from mice infected with Brucella for at least 2 months or from mice vaccinated with a protein-bound cell wall peptidoglycan Brucella fraction completely stopped dissemination. Brucella lipopolysaccharide and polysaccharide cross-reacting Yersinia immune sera reduced dissemination. Both peptidoglycan and lipopolysaccharide immune sera injected simultaneously with an intravenous challenge caused a shift in Brucella from spleen to liver. When immune sera were injected simultaneously with an intravenous challenge, the kinetics of splenic infection showed two effects: an early one, optimally measured at day 7 postchallenge, showed reduced numbers in the spleen due to the shift of Brucella to the liver; a late effect, measured at day 21 postchallenge, showed reduced numbers in spleen and liver with nearly complete clearance by day 49 postchallenge. Brucella lipopolysaccharide and cross-reacting bacterial antisera induced the early effect only, whereas peptidoglycan and infected mouse sera induced both effects. When peptidoglycan immune serum was injected 2 or 7 days after intravenous challenge, the late effect was somewhat reduced. Hence, immune sera to protein and polysaccharide surface antigens can (i) prevent dissemination of systemic infection and (ii) help destroy intercellular bacteria (protein antigen only). These effects may represent a large part of vaccinal immunity.

Animals↗
PubMed1983

A laboratory reference vaccine to titrate immunogenic activity of antibrucella vaccines in mice.

The number of bacteria (CFU) in spleens of mice fifteen days after a standard intraperitoneal challenge of Brucella abortus, is dependent on vaccinal immune status of mice. From this observation, a control method of vaccinal activity was previously proposed, which classified the responses in relation to fixed reference values. A reference vaccine, a lyophilized formalin-killed bacterial cell suspension of B. melitensis strains H38 was prepared and titrated. From the dose response curve, the quantities giving reference values were calculated and expressed in a Unit system. This vaccine makes possible inter-laboratory comparisons of vaccinal activity, that can be expressed on the Units basis.

Animals↗
PubMed1982

[Development of a splenic infection in mice of 4 strains, inoculated by the venous route, with 3 doses of Brucella abortus].

Brucella abortus strain 544 was inoculated at three doses into outbred female Swiss mice CD-1 and OF1, and inbred strains CBA and DBA/2. Brucella were enumerated in the mice spleens which were first weighed, at 2, 7, 14, 21, 35 and 49 days post-challenge. A phase of multiplication occurred, reaching a maximum between 7 and 21 days according to the mice, but independently of challenge doses. A decreasing phase followed that was still going on in CD-1 and OF1 mice at 49 days, but ended by a plateau or recurrence in CBA and DBA/2. Spleen weights increased from the beginning to a maximum then decreased. This maximum was reached either before (DBA/2), after (CBA) or at the infection acme (CD-1, OF1). Hence, immune mechanisms may be turned on according to several sequences, but feed-back regulation would work similarly in different breeds.

Animals↗
PubMed1982

[Course of chronic brucellosis in mice is not improved by administration of a vaccinal antigen].

Of1 female Swiss mice inoculated with Brucella abortus virulent strain 544 since four weeks, were treated by subcutaneous injections of a B. abortus 19 cell-wall vaccine extracted by boiling sodium dodecylsulfate suspended in oil adjuvant (PG-B19). Vaccinations were administered at 10 or 100 micrograms dose per mouse, two to four times, at 15-30 days interval. Groups of six mice were killed at 4 week intervals up to 24 weeks post challenge to follow the evolution of splenic infections by enumeration of brucella. No significant changes were elicited by treatments. Since in this system, infections evolve spontaneously and progressively toward self-cure, an additional antigenic stimulation is unable to improve the immune response efferent arc.

Animals↗
PubMed1976

[Structure and constituents of Brucella. Characterization and biological properties of the fractions].

The analysis of the components of a bacterium may be envisaged from the biological aspect (fractionation), the ultrastructural aspect (staining of the structures examined electron-microscopically), and the biological aspect (measure of an activity). In this report we attempt to examine the components of brucella from all three aspects simultaneously. The brucella envelopes have the same ultrastructure as that of gramnegative bacteria: outer membrane, thick stratum or peptidoglycane, periplasmic space, cytoplasmic membrane. The outer membrane of brucella in phase S contains many types of polysaccharides: (1) the lipopolysaccharide (LPS) (S) and polysaccharide B are solubilized by the phenol-uater and ether-water methods, by trichloracetic acid (TCA), by heated sodium dodecyl-sulfate (SDS). The exact localization of polysaccharide B is not known; by the phenol-water extraction method, the LPS (S) in its toxic form (endotoxin) passes in solution into the phenol phase, unlike the endotoxin of enterobacteria, which passes into the aqueous phase. In addition to its toxicity, this LPS (S) is responsible for reactions of immediate hypersensitivity as well as serological reactions towards the standard antigen. It presents A + M antigenic sites; (2) one or more of the polysaccharides remains unsolubilized by the ether-water method, but solubilized by heated SDS; (3) a polysaccharide is linked to peptidoglycane. The structure of the outer membrane of the brucella in phase R is analogous to that of LPS, carrying antigen R, characteristic of these strains. This antigen may be utilized for the serological diagnosis of infections due to brucella R (B. ovis) or vaccinations by a vaccine in phase R. The peptidoglycane fraction extracted by the heated SDS has a more complex structure than that of E. coli: it consists of a supplementary outer layer containing amino acids and polysaccharides. This fraction has a vaccinal activity. A soluble protein fraction, without organized structure, no doubt of cytoplasmic origin, may be extracted by a cold saline solution. This fraction, known as "brucelline", reveals delayed hypersensitivity when injected intradermally. The biological activity of the other structures (periplasm, cytoplasmic membrane, ribosomes...) is not known. Biological activities have been attributed to fractions, but since these are badly defined from the structural point of view it is difficult to determine the connection between activities and structures.

Antigens, Bacterial↗
PubMed1976

[Treatment of experimental brucellosis of mice and guinea pigs by rifampicin].

The intracellular and bactericidal activity of rifampicine was observed in the treatment of experimental brucellosis in the mouse and guinea pig. Batches of mice infected by intraperitoneal route with B. melitensis, strain 53 H 38, were treated with rifampicine (20 mg/kg/day) or with tetracycline-base (200 mg/kg/day). When the treatment begins 14 days after inoculation and lasts a week, the rifampicine produces a more significant decrease of the weight of the spleen than does tetracycline. After 14 days' treatment, apart from this effect, the degree of infection of the spleen decreases at least 10(5) times with rifampicine and 10(2) times with tetracycline. After 21 days, bacteriological sterilization is obtained with rifampicine whereas 66% of the tetracycline-treated mice are still infected. However, a residual infection of weak intensity persists in 6.6% of the rifampicine-treated mice against 75% of the tetracycline-treated mice, as shown by an injection of Corynebacterium parvum and a cortisone treatment at the end of the antibiotherapy. If the antibiotic treatment begins on the day of inoculation, the greatly superior efficacity of rifampicine is in that case more rapid. Rifampicine (100 mg/kg/day) offers comparable efficacity in the guinea pig infected by intraperitoneal route with B. abortus strain 544; these efficacity is shown by the decrease in the weight of the spleen and the intensity of splenic and ganglionic infection. The rapid decrease of agglutinins and amboceptors after 7 days of treatment suggests the possible role of a suppressor of this antibiotic. Finally, the effect of rifampicine on the growth of the guinea pig was noted.

Animals↗
PubMed1976

Vaccination against bovine brucellosis with a low dose of strain 19 administered by the conjunctival route.

Eighteen 25 month old cows were vaccinated once either with 10(6) to 10(10) living bacteria of Brucella abortus B 19 by the conjunctival route, or with 2.5 to 5 X 10(10) formalin-killed bacteria of the same strain by subcutaneous injection. Fifteen days post-vaccination, low but definite agglutination titers were present in sera of cattle receiving 10(10) living bacteria by the conjunctival route, whereas high titers were observed in the control group given subcutaneous injection of killed bacteria (table I). Agglutination reactions were negative in sera from all cattle receiving less than 10(10) bacteria, and complement fixation tests were negative with all sera. Seventy-one 4 month old claves were vaccinated by the conjunctival route with different doses (10(6) to 10(10)) of living bacteria, either freshly prepared or lyophilized. At autopsy about 15 or about 30 days later, the parotid, submaxillary and retropharyngeal lymph nodes were removed and cultured on Brucella selective medium. Blood samples were taken at autopsy for testing by agglutination, complement fixation, Coombs test and (for some samples) by the Rose Bengal plate test. Colonization of at least one lymph node was observed in 26 of 34 calves given 10(9) bacteria, in all 9 calves given 5 X 10(9) bacteria and in all 12 calves given 10(10) bacteria. Serological responses were demonstrated rarely, and then only in agglutination and Coombs tests. The 5 X 10(9) dose, wich following conjunctival inoculation consistently colonized the regional lymph nodes without inducing significant serological response, would be the most suitable dose for the vaccination of calves and cows.

Animals↗
PubMed1976

Vaccination against bovine brucellosis with a low dose of strain 19 administered by the conjunctival route. III. -- Serological response and immunity in the pregnant cow.

Seventy-four heifers, 7 to 12 months old, were randomized in four groups: group A, 8 heifers as controls; group B, 19 heifers vaccinated subcutaneously with 9 X 10(10) Brucella abortus strain B 19; group C, 19 heifers vaccinated as in group B, then revaccinated by the conjunctival route 6 to 8 months later with 5 X 10(9) bacteria; group D, 28 heifers vaccinated twice by the conjunctival route with the same dose and time intervals as in group C. Serological responses in agglutination, complement fixation and Rose Bengal tests were typical of those following standard vaccination with Strain B 19 in group B. Iu group C after the booster vaccination, there was a transient rise in titers which lasted about 3 months. Iu group D, titers were infrequent, low, and lasted no more than 8 weeks, after both primary and secondary vaccination. Fifty of the heifers, when 4 1/2 to 6 1/2 months pregnant, were challenged by the conjunctival route, with 16 X 10(6) B. abortus strain 544. Calves were born at full term (greater than or equal to 264 days) to 1/7 heifers in group A, 6/12 in group B, 8/II in group C and 14/19 in group D. Serological tests every two weeks after challenge; bacteriological examination of vaginal mucus, colostrum, foetuses and dead calves; bacterial enumeration of ten mixed samples of lymph nodes and organs taken at slaughter about 6 weeks after parturition, were made to determine the infection status of the heifers. Brucella was isolated at some time from 7/7 heifers in group A, II/I2 in group B, 6/I2 in group C and I4/I9 in group D. Five heifers (2 in B, I in C, 2 in D) cleared themselves of infection between parturition and slaughter, The average degree of infection per group at slaughter, expressed as a logarithmic index of the number of Brucella isolated from the ten samples, was significantly lower in the three vaccinated groups than in the controls, and in groups C and D than in groups B, and it was not significantly different in group C and D. For field vaccination, a booster vaccination by the conjunctival route, as in group C, would provide more protection than the standard vaccination without serious interference in routine diagnostic tests. Two vaccinations by the conjunctival route, as in group D, would be simpler, more economical and at least as effective as the standard system of vaccination, and would have the advantage that vaccination could be done at nay age without risk of serological response.

Agglutination Tests↗
PubMed1975

Vaccination against bovine brucellosis with a low dose of strain 19 administered by the conjunctival route. I.--Protection demonstrated in guinea pigs.

Guinea pigs were vaccinated with different doses of strain Brucella abortus B 19, subcutaneously (SC) or by the conjunctival route (C), once or a second time three months later. Agglutination and complement fixation titers were determined on sera of guinea pigs taken at random at intervals from each vaccine group. Protection afforded by the vaccination was determined by intramuscular injection of the challenge strain, B. abortus 544 (5 X 10(3) bacteria) three months after the last vaccination. Forty days later the guinea pigs were killed and Brucella looked for and counted in the spleen and lymph nodes. After conjunctival vaccination with 10(6) or 10(7) bacteria, seriological responses were weak and transient even after the re-vaccination, and were lower than after subcutaneous vaccination with the 10(6) dose, and much lower than after the standard vaccination dose of 7 X 10(9) given subcutaneously. Protection, expressed as percentage of guinea pigs free of infection at autopsy (table 4) was 40 p. 100 in the standard vaccination group (SC, 7 X 10(9)) and 57 p. 100 in groups receiving successively 7 X 10(9) (SC) and 10(6) or 10(7) (C). Two successive conjunctival vaccinations with the 10(6) to 10(9) doses gave 47 to 60 p. 100 protection; two SC vaccinations with the 10(6) dose gave 75 p. 100 protection. All the control guinea pigs were heavily infected. The differences in protection rate among the groups vaccinated twice were not significant. Since vaccination through the conjunctiva with two successive instillations of 10(7) bacteria induced only a weak antibody response and protection equivalent to that of standard subcutaneous vaccination, the method appears worthy of application in cattle.

Animals↗
PubMed1973

Anti-gamma haemolysin as a diagnostic test in staphylococcal osteomyelitis.

The anti-alpha-haemolysin test is widely used in the diagnosis of staphylococcal osteomyelitis. An additional test would be welcomed because raised antibodies to this antigen are not seen in all proven cases. This communication reports that anti-gamma-lysin was present in the serum of most of the 19 patients with proven staphylococcal osteomyelitis studied here. In two cases followed up after chemotherapy was initiated both tests indicated the satisfactory progress of the patient.

Adolescent↗