Serotyping of chlamydial clinical isolates from birds with monoclonal antibodies.

Forty-nine avian chlamydial strains, isolated mainly from various regions in France and from different species of birds, were analyzed and tested with a panel of nine monoclonal antibodies (MAbs) by the indirect microimmunofluorescence test (MIF). The MAbs included five serovar-specific MAbs, three MAbs raised against Chlamydia psittaci and Chlamydia pecorum ovine strains, and one genus-specific MAb. Of the 49 isolates, 41 came from parrots or budgerigars; the rest were from pigeons, a canary, a duck, and a dove. Two additional strains were from unknown hosts. Most of these avian strains were successfully serotyped according to their reactions with five serovar-specific MAbs by the MIF test. The serovars of 44 strains were determined: 39 were of serovar A, 3 of serovar B, and 2 of serovar E. The remaining five isolates were unclassified because they did not react with any of five serovar-specific MAbs but did react with genus MAb or the MAbs produced with ovine strains. The five unclassified isolates (two from budgerigars, two from Gabon gray parrots, and one from a duck) indicate that one or more additional serovars of C. psittaci exist in birds. The heterogeneity within each subgroup was evident because the 49 avian isolates gave 10 subgroups when the results of the five serovar-specific MAbs were combined with results from the three MAbs produced with ovine strains. This heterogeneity of the serovar isolates, as shown by the combination of MAbs, could provide strain markers very useful for epidemiologic studies.

Biodistribution of mixed fluorocarbon-hydrocarbon dowel molecules used as stabilizers of fluorocarbon emulsions: a quantitative study by fluorine nuclear magnetic resonance (NMR).

19F NMR spectroscopy was used to determine quantitatively the organ distribution and organ retention time in rats of the mixed fluorocarbon-hydrocarbon dowel molecule C6F13CH = CHC10H21 (F6H10E), which stabilizes highly concentrated injectable fluorocarbon emulsions destined for in vivo oxygen transport and delivery. The only fluorine resonances detected in the 19F NMR spectra of the organs analyzed were those of the F6H10E dowel itself, indicating that metabolites, if present, have very low concentrations (< 10(-4) M, limit of our assay). The F6H10E content in the liver peaked 1 day after administration (7 days for the spleen). At a dose of 3.6 g/kg body weight, the half-life of F6H10E in the liver was 25 +/- 5 days.

Perfluoroalkylated surfactants: relationships between structure and acute toxicity in mice.

New single chain neutral, and single and double chain zwitterionic perfluoroalkylated surfactants or co-surfactants have been evaluated for in vivo applications. A study of the relationship between structure and acute toxicity in mice is presented. Acute toxicity evaluations i.v. in mice indicate the following trends (increasing tolerance): zwitterionic single-chain less than neutral single-chain less than zwitterionic double-chain and, where the polar head is concerned, single-chain compounds: phosphocholine less than phosphoramidate less than trehalose approximately sucrose less than maltose less than xylitol.

[Bovine brucellosis caused by Brucella melitensis in France]. / La brucellose bovine à Brucella melitensis en France.

Each Brucella species is known to have a definite host preference. In this respect, brucellosis in cattle is primarily due to B. abortus. As part of an investigation of the species and biovars responsible for bovine brucellosis in France, 312 strains have been examined since 1978 by the methods recommended by the Subcommittee on the Taxonomy of the genus Brucella. Of these, 264 (85%) were indeed classified as B. abortus members. However the 48 others (15%) had all the characteristics that define the species B. melitensis which usually affects small ruminants. Of these 48 strains, 43 (90%) came from the southern part of France in which B. melitensis infection in sheep and goats is enzootic and where the dissemination of this species by sheep flocks moving to mountain pastures most often accounted for cattle contamination. Evidence that B. melitensis infection in cattle traced to infected small ruminants was also strongly supported by biotyping. Of the 48 strains, 45 (94%) indeed were B. melitensis biovar 3 which is the most common in infected sheep and goats in France. B. melitensis infected cattle, which also constitutes a serious risk for public health, must therefore be considered by veterinary authorities because of epizootiologic implications in eradication and control programmes of sheep and goat brucellosis.