agar and Dysentery--Bacillary

From 1989 through 1991, 6033 stool specimens from patients at Orleans Hospital (France), were cultured for enteric pathogens. Hektoen agar (HE) was compared with Salmonella-Shigella agar (SS) after direct streaking and after overnight enrichment in Mueller-Kauffmann broth. Yersinia strains were not computed. Seven strains of Salmonella serotype Typhi were isolated, on both media, and excluded from computations for discussed reasons. Out of a total of 9 Shigella strains, HE isolated 9 and SS isolated 7. No statistically significant difference appeared about isolation of non-Typhi Salmonella strains (127 vs 114 from direct streaking, 237 vs 243 after enrichment). Predictive values of suspicious colonies were not statistically different. Numbers of false positives were not different, except for black centred colonies of the direct streaking (231 on HE vs 186 on SS, p less than 0.05). The skill of technologists was not taken into account but was found likely to be more accurate on SS agar. This data suggest that, since the frequency of Shigella sp became much lower, the differential of efficiency of HE vs SS agar is no longer obvious in human medical routine.

Topics: Agar; Bacteriological Techniques; Culture Media; Dysentery, Bacillary; Feces; Humans; In Vitro Techniques; Salmonella; Salmonella Infections; Salmonella typhi; Shigella

Growth promoting properties and selectivity of 11 commercially produced media recommended for Salmonella and Shigella isolation were evaluated. The following media were tested: EMB (Eosin methylene blue agar), Endo, Płoskiriew, MacConkey, DC (Deoxycholate citrate agar), SS (Salmonella-Shigella agar), BS (Bismuth sulfite agar) and Mueller-Hinton as a medium with no selective properties. The media were produced in Czechoslovakia, East Germany, West Germany, Poland, and Soviet Union. Quantitative studies were performed on 71 strains representing 8 genera of Enterobacteriaceae family; both reference and wild newly + isolated from clinical material strains were included. It was found that none of DC and BS media provided suitable growth conditions for Shigella strains and in particular for S. dysenteriae, S. boydii, and S. flexneri. It was also found that the same medium (name and content) but derived from different producer can vary significantly in respect to growth promotion and selectivity especially for Shigella strains. All media with selective, differentiating properties for Salmonella and Shigella isolation should not be used without previous quantitative control test for their selective and growth promoting properties checked by user. The need for such a control performed both on reference and freshly isolated strains was shown in this study. In the set of control strains all species of Shigella should be represented.

Topics: Agar; Bismuth; Colony Count, Microbial; Culture Media; Deoxycholic Acid; Dysentery, Bacillary; Growth Substances; Humans; Salmonella; Salmonella Infections; Shigella; Temperature

Topics: Agar; Child; Child, Preschool; Culture Media; Deoxycholic Acid; Diarrhea; Dysentery, Bacillary; Female; Humans; Infant; Infant, Newborn; Male; Shigella; Xylose

Topics: Agar; Bacteriological Techniques; Chloramphenicol; Culture Media; Dysentery, Bacillary; Humans; Shigella sonnei

A mixture of Shigella sonnei and Eubacterium lentum produced H2S in triple sugar iron agar; however, neither produced any in pure culture. A second culture of S. sonnei, isolated in Japan, is thought to be the first documented H2S+ Shigella.

Topics: Agar; Anaerobiosis; Child, Preschool; Dysentery, Bacillary; Female; Humans; Shigella sonnei

Topics: Agar; Child, Preschool; Culture Media; Dysentery, Bacillary; Humans; Infant; Infant, Newborn; Shigella; Specimen Handling

Topics: Agar; Bacteriophages; Dysentery, Bacillary; In Vitro Techniques; Shigella

Topics: Agar; Bacillus; Dysentery; Dysentery, Bacillary; Lacticaseibacillus casei; Yeast, Dried

Topics: Agar; Bismuth; Dysentery, Bacillary; Shigella; Sulfites