[The characterization of a Spanish strain of Borrelia burgdorferi]

BACKGROUND

The characteristics of a Spanish strain of Borrelia burgdorferi, the spirochete which causes Lyme's disease, and which, up to the present, has not been isolated in Spain, are described.

METHODS

The organism was obtained from ticks (Ixodes ricinus) from the northern part of Spain. It was studied in culture by dark field microscopy and the internal structure observed by electron transmission. The antigenic composition was analyzed under polyacrylamide electrophoresis, immunoblot and reactivity against monoclonal antibodies. Plasmid analysis was carried out by Southern blot.

RESULTS

In culture the length of the organism is somewhat shorter than normal. It grows slowly and tends to autoagglutinate. It has 6-13 periplasmic flagella. The antigenic analysis of this microorganism through immunoblot and reactivity against different monoclonal antibodies showed differences with regards to other North American strains, with the most significant being the composition of certain proteins of the surface of the organism. These differences may have clinical repercussion. DNA analysis by Southern blot demonstrated slight differences in regard to the composition of plasmids compared to other strains analyzed.

CONCLUSIONS

Borrelia burgdorferi exists in Spain. The isolated strain shows peculiar characteristics with respect to others analyzed. The availability of an autochthonous strain may allow more reliable serological diagnosis in Spain.

A study of the acid phosphatase of Treponema denticola

This study describes some of the properties of the acid phosphatase of the potential periodontopathogen Treponema denticola. The highest enzyme activity was found in 87 h old cells. Two optimum pHs for enzyme activity were detected, one at pH 4.8 and another at pH 6.2. Divalent cations did not influence the acid phosphatase of T. denticola. The anion F- added in the form of NaF and at a level greater than 20 micrograms/ml F- diminished the activity of the acid phosphatase of intact cells of T. denticola. The addition of 10 micrograms/ml F- as SnF2 induced a statistically significant reduction of acid phosphatase activity. The apparent Km for the acid phosphatase was 7.3 mM with p-nitrophenyl phosphate as substrate. Fluoride appeared to be a noncompetitive inhibitor of the enzyme with an apparent Ki of 0.3 mM. Acid phosphatase may be released partially in osmotic shock fluids. Also, 7-diazonium-1, 3-naphthalene disulfonate, which is incapable of penetrating the bacterial permeability barrier and is known to inactivate enzymes found in the bacterial periplasmic place, suppressed the activity of the acid phosphatase in intact cells of T. denticola.