IMÁGENES MICROBIOLÓGICAS

Cytopathic effect in BHK 21 (C13) cells inoculated with Leptospira interrogans serovar Pomona isolated from a porcine abortion

BHK 21 (C13) cells inoculated with a wild strain of Leptospira interrogans serovar Pomona isolated from a porcine abortion exhibited cythopathic effect (CPE) consistent in degenerative morphological alterations whereas no cell changes or alterations were observed in cells infected with a non-pathogenic Leptospira biflexa serovar Patoc strain.
BHK 21 (C13) cells were seeded on 24 well cell culture plates containing MEM-E medium with 10% fetal bovine serum and no antibiotics; 5 x 10⁴ cells per ml were poured into each well. Cell cultures were infected with one milliliter of a suspension from each separate strain containing 1 x 10⁷ leptospires/ml. Cells were subsequently incubated at 37 °C in a 5% CO₂ atmosphere and fixed with methyl alcohol at 24 and 48 h pi. Cell morphology and leptospiral CPE were microscopically assessed in May Grünwald-Giemsa stained smears. In this study, several CPE caused by a wild strain of L. interrogans serovar Pomona were observed at 24 h pi: ballooning, loss of cell structure, vacuolization and lysis (Figures 1 and 2). This fact demonstrated the ability of leptospires to produce cell damage. No changes were observed in BHK 21 (C13) cells infected with a non-pathogenic L. biflexa serovar Patoc strain (Figure 3). Origin of Leptospira strains: Laboratory of Leptospirosis, Instituto de Patobiología, CICVyA-CNIA, Instituto Nacional Tecnología Agropecuaria, Castelar, Buenos Aires, Argentina.

Figure 1. BHK 21 (C13) cells inoculated with a wild type L. interrogans serovar Pomona. Arrows show vacuolization. May Grünwald-Giemsa. 400X

Figure 2. BHK 21 (C13) cells inoculated with a wild type L. interrogans serovar Pomona. Arrow shows ballooning and loss of cell structure. May Grünwald-Giemsa. 400X

Figure 3. BHK 21 (C13) cells inoculated with L. biflexa serovar Patoc. No cell changes or alterations are observed. May Grünwald-Giemsa. 400X

B. Brihuega¹, A. Venzano¹, O. Zabal², D. Funes¹, C. Auteri¹, G. Romero¹, L. Samartino¹.

¹Instituto de Patobiología.
²Instituto de Virología.
Centro de Investigaciones en Ciencias Veterinarias y Agronómicas. INTA. Las Cabañas y Los Reseros (1712) Castelar, Buenos Aires, Argentina.

E-mail: bbrihuega@cnia.inta.gov.ar