Molecular analysis of Salmonella paratyphi A from an outbreak in New Delhi, India.

Letters clinical presentation of the patients, response to trivalent botulinum antitoxin, and isolation of toxigenic C. butyricum from one of the consumed food articles strongly suggest that the outbreak was caused by food contaminated with toxigenic C. butyricum. Neurotoxigenic C. butyricum was first reported in 1986 in two cases of infant botulism in Rome (6). Recently, neurotoxigenic C. butyricum was isolated from the food implicated in an outbreak of clinically diagnosed type E botulism in China (7). In this outbreak, it appears that sevu, because of improper storage, was contaminated with the spores of C. butyricum, which subsequently germinated and produced toxin. To the best of our knowledge, this is the first report of neurotoxigenic C. butyricum causing foodborne botulism in India. The changing epidemiology of foodborne disease as highlighted in this report calls for improved surveillance, including the development of new technology for identifying outbreaks. for polyvalent botulinum antitoxin; and the medical and paramedical staff of Civil Hospital, Ahemdabad. of an organism that produces type E botulinal toxin but which resembles Clostridium butyricum from the feces of an infant with type E botulism. et al. Characterization of a neurotoxigenic Clostridium butyricum strain isolated from the food implicated in an outbreak of food-borne type E botulism. To the Editor: In the context of emerging infectious diseases, enteric fever caused by Salmonella paratyphi A deserves increased attention and vigilance, although its severity is often milder than that of S. typhi disease. Outbreaks associated with this organism are exceedingly rare but have recently been reported in India (1) and Thailand. In India, the first reported outbreak of disease associated with S. paratyphi A (1) provided an opportunity to study the molecular epidemiology of infection caused by this organism. A total of 18 human blood isolates of S. paratyphi A, 13 from the outbreak in New Delhi, India (from September to October 1996) (1) and 5 sporadic isolates from cases unrelated to the outbreak, were used in this study. A total of 36 culture-positive cases were detected during the 6-week outbreak. All strains were phage type 1 and were sensitive to all antibiotics tested. Isolates were analyzed by ribotyping and pulsed-field gel electrophoresis (PFGE) (2,3). PFGE/ribotype profiles were assigned arbitrary designations and analyzed by defining a similarity (Dice) coefficient, F (3), where F = 1.0 indicates complete pattern identity and F = 0, complete dissimilarity. The five sporadic isolates of S. paratyphi A …