Growth of Leptospira pomona and Its Effect on Various Tissue Culture Systems

Abstract

NOR-MAN G. MILLER, AND ROBERTA J. WHITE. Growth of Leptospira pqmona and its effect on various tissue culture systems. J. Bacteriol. 92:502-509. 1966.-Leptospira pomona strain 3341 was grown in association with primary fetal bovine kidney (PBK) and human embryonic skin-muscle fibroblastic (HE) cells in Eagle's minimal essential medium (MEM) with 5% sheep serum. Growth curves of leptospires in PBK and HE cell cultures showed no substantial increase in growth above that obtained in Eagle's MEM in the absence of tissue culture cells. This suggested that no stimulatory growth factors for leptospires were produced by the tissue cells. Fibroblastic cells of the PBK monolayer showed separation, deterioration, and, finally, complete disintegration. Epithelial-like cells remained unaffected. HE cells showed the same cytopathic effect as PBK fibroblastic cells, indicating that this effect was not limited to PBK fibroblastic cells. Warthin-Starry stains of PBK and HE cell monolayers showed masses of leptospires adhering to fibroblastic cells, whereas only a few were seen on epithelial-like cells. Large numbers of leptospires on the surface of fibroblastic cells are very likely associated with the cytopathic effect. Dislodgment of leptospires from fibroblastic cells did not increase the total number ot spirochetes in the culture. This indicated that leptospiral growth did not occur on the surtace of these cells.

Enhancement of Growth of Leptospira icterohaemorrhagiae by Tissue Cell Cultures

“…When Eagle's medium was supplemented with haemolysed serum, in medium alone or in association with cell lines Clone B or BHK 21, the leptospirae grew abundantly. The latter results are very similar to those obtained by Miller et al (1966) in the culture of serotype pomone in Eagle's medium, with primary foetal bovine kidney and human embryonic skin muscle fibroblast cell cultures-Eagle's medium supplemented with non-haemolysed serum produced poor growth in medium alone. In association with cell line Clone B the growth was enhanced but inferior to that obtained in ME medium supplemented with haemolysed serum (with or without tissue cells).…”

Cytotoxic Factor in the Blood and Plasma of Animals During Leptospirosis

“…The effect of plasma from infected hamsters on HeLa cells. Earlier studies using whole cultures of virulent leptospires (12,14) as well as CPE factor prepared from culture filtrates (24) showed that a CPE occurred only on fibroblastic but not epithelial cells; consequently it was of interest to determine whether this was also true for cytotoxic factor (CTF).…”

“…The selective action of CTF on L cells (fibroblastic) and not HeLa cells (epithelial) correlates with the activity of whole viable leptospires (14) and their products (24) on these cell types. This may be attributed to the affinity of CTF to the mucopolysaccharide on the surface of fibroblastic cells (15).…”

“…A significant difference between the activity of whole leptospires, supernatant fluid from cultures, and CTF on cell monolayers was that CTF produced extensive CPE in 24 h, whereas the supernatant fluid and whole cultures required 6 (24) and 9 (12,14) days, respectively, for comparable CPE to occur. This may be because host tissues provide a more complete medium for the production of toxin than the culture media currently used for growing leptospires.…”

Genetic variability and expression of sphA and sphB genes and immunogenicity of SphA and SphB of Leptospira borgpetersenii serovar hardjo

“…leptospiral cytotoxic factor (108,109). TTie cytotoxic activity has not been characterized, and it is unclear if it is limited solely to virulent organisms.…”