Different properties of botulinum neurotoxin ( ntbo) type a between strains obtained from soil and from cases of infant botulism of mendoza.

PATRICIA CABALLERO; PAREJA V; L.DE JONG; LOPEZ GC; RA FERNANDEZ; SOSA MA

San Luis

Congreso; XXX Reunión Anual de la Sociedad de Biología de Cuyo; 2012

Sociedad de Biología de Cuyo

Infant botulism (BL) is a wideworld distributed; pathology caused by Clostridium botulinum (Cb) type A (toxiinfection). The soil (Su) is the main reservoir of the bacterial and probably the main source of infection in infants. The neurotoxin (NTBo) obtained from type A Cb is a complex of » 900 kDa (exclusive to this serotype). We have previously found morphological differences between colonies of strains obtained from diverse sources, and compared to prototype A Hall. The aim of this work was to compare NTBo from strains obtained from soil and patients with BL. To asses this, five strains were selected from Su, five from BL and three were from the prototype A Hall. Toxigenicity of strains was controlled by IP inoculationin white mice inCCM subculture (34ºC, 96 h). NTBo generated under anaerobic conditions (34º C, 96 h) was rescued from the medium, centrifuged and the supernatants were purified by salting. Toxigenicity and the DL50/ml was estimated (Reedand Muench). The specific activity (AE = DL50/mg protein) of the toxins was determined after measuring protein concentration, and also was evaluated their hemagglutinating activity (HA). Moreover, purified NTBo was analysed by electroforesis in gels of polyacrilamide (SDS-PAGE) under non-denaturing conditions. Results: We observed that AE varied significantly (p ≤ 0,001) between NTBo of Su and BL strains (Su: 3,93 ± 0,59; BL: 1,73 ± 0,44). In addition, both toxins exhibited apparent Mr of 300 kDa, in concordance with the absence of HA, and unlike the strain prototype (900 kDa), which showed a high HA. We concluded that NTBo from BL patients is molecularly similar to that from Su strain, although with different AE. This could indicate that either both strains are different or they are similar although the toxin may be processed somewhere in the patient.