Bacteriology of shigelosis

Abstract

In this paper there are given the results obtained in the bacteriologic diagnosis of organisms of the Shigella genera in São Paulo, Brazil, corresponding to the work of more than four years. The methods adopted are described and discussed, underlining the importance at the present state of knowledge regarding the antigenic structure of the organisms under consideration, with details about the methods for the obtention of the diagnostic sera used. Without discussing details about the classification of the "Shigella", the author gives the 3 following groups: 1rst. group: manitol + lactose - Sh. paradysenteriae, Sh. alkalescens, Sh. tietê; 2nd. group: manitol + lactose - Sh. sonnei, Sh. díspar; 3rd. group: manitol - lactose + Sh. dysenteriae, Sh. ambígua, Sh. sp, grupo Large-Sachs. In the differentiation of the components of the paradysenteriae group, the criterion used by J. S. K. Boyd, modified by K. M. Wheeler, is adopted. It has not been possible to find any antigenic difference between the Sh. paradysenteriae type VI and the new type described as Sh. rio. Like A. Assis, the author believes that Sh. tietê must be considered as a new shigella type and admits also the possibility of variants lactose positive in this group. His personal observations refer to:lrst.) The use of the swab method compared with the stool culture in 307 children with and without clinical diagnosis of diarrhea. Positive cultures in Swab 75% and Stool culture 57%. The positive cultures were: Sh. sonnei (12), Sh. paradysenteriae (9), Sh. alkalescens (6), Sh. ambigua (1); the death rate was: Sh. paradysenteriae (1), Sh, sonnei (2), Sh. alkalescens (2).2nd.) From 5.211 stool cultures made during a period of four years, 497 were positive for Shigella. The Shigella types encountered were: : Sh. paradysenteriae type I (16), type II (97), type III (30), type IV (28), type V (11),  type VI (20), type VII (4),  type VIII 2), no typed (18); Sh. alkalescens (73), Sh. tietê (50), Sh. sonnei (100), Sh. dysenteriae (6), Sh. ambigua (14), Sh. sp. Sachs Q 771 (3), Sh. sp. Sachs Q 454 (4).3rd). One hundred patients with chronical intestinal disease. In 23 the author was able to demonstrate the presence of a shigella organism in the stool: Sh. paradysenteriae (7), Sh. sonnei (3), Sh. alkcalescens (8), Sh. dispar (5), In two instances there was found more than one shigella type. The stool culture was made every week and for the same patient was a minimum of 2 to a maximum of 15. It was interesting that in the same patients the shigella was not found in the stool for long periods.