Reaction and response of newborn guinea pigs to experimental Salmonella typhi infection.

Newborn guinea pigs, orally infected with Salmonella typhi were examined at various intervals of time in order to determine bacterial distribution in tissues and to establish possible correlation with the clinical aspects manifested. Histopathological examination evidenced typical lesions in jejunum, ileum, caecum and especially in regional lymphatic tissues. Spleen, liver and mesenteric lymph nodes presented granulomatous lesions similar to those observed in in human typhoid fever. After oral administration, the animals reacted with anorexia, febrile reactions, bacteremia, diarrhoea, positive stool cultures, dehydration, lethargy and antibodies too were produced. Our results indicate that typhoid infection may be induced in newborn guinea pigs; the model may be used for an assessment of attenuated live typhoid vaccine control.