FACTORS WICH AFFECT THE
VIABILITY OF LEPTOSPIRES
Factor which affect the viability of leptospires are:
Imperfectly cleaned glassware.
Inappropriate media
- Milk samples are best inoculated on solid medium (EMJH) with 1% agar. Immediately after
sampling inoculate at 1:10-1:10,000 dilutions. Comparisons were made of semi-solid and
solid media. Only solid medium was capable of isolating from cow's milk. Cultures from
milk were only obtained during the first 10 days of "mastitis". In culture
isolations from cow's urine, semi-solid medium with 5FU proved to be the most efficient.
Filtration through 0,22 um filters should be considered as useful.
Inhibitory substances
- When rabbit serum is to be added to the medium this serum should first be checked for
antibodies against leptospires. Even fetal calf serum should alwaysbe checked for the
presecne of antibodies against leptospires.
Antibiotic therapy
- Antibiotic treatment reduces the chance of isolation
Contamination
- Contamination with other micro-organiss, i.e. overgrowth with bacteria
Incubation temperature
- The optimum temperature is from 28 C till 30 C
pH of the medium
- It is important that the medium has a pH from 7.2 to 7.4.