Biochemical tests for the differentiation of Klebsiella and Cloaca

Abstract

The, l a t e s t report (1 ) of t h e Enterobacteriaceae Subcommittee (1953) d e f i n e s t h e K l e b s i e l l a group, ( i n c l u d i n g Aerobacter aerogenes) a s made up of nonmotile, indole-negative, MR-negat i v e , VP-positive, c i t r a t e -p o s i t i v e , non-gelatin-liquefying, Gram-negative rods. They a l s o decompose urea, although t h e i r u r e a s e a c t i v i t y is much weaker t h a n t h a t of Proteus. While a l l t h e s e biochemical c h a r a c t e r s a r e considered t y p i c a l of t h e group, t h e r e p o r t a l s o mentions t h a t included i n t h e group a r e i n d i v i d u a l c u l t u r e s which give aberrant r e s u l t s i n one o r more of t h e s e t e s t s . Although it was r e a l i z e d t h a t m o t i l e and nonmotile s t r a i n s had many c h a r a c t e r s i n common, a s t h e Subcommittee e l i m i n a t e d m o t i l e s t r a i n s from K l e b s i e l l a , it was possible t o c o r r e l a t e m o t i l i t y with biochemical behaviour. There a r e , t h e r e f o r e , sound reasons f o r p l a c i n g t h e s e m o t i l e s t r a i n s i n a s p e c i a l group of t h e i r own, t h e Cloaca group.Brooke (2) compared 108 c u l t u r e s of Cloaca, 71 of them motile, with 303 nonmotile K l e b s i e l l a s t r a i n s . He found t h a t a l l s t r a i n s of Cloaca l i q u e f i e d g e l a t i n , none produced g a s from g l y c e r o l , one fermented i n o s i t o l , one d u l c i t o l , 20 were u r e a -p o s i t i v e and o n l y 9 promptly fermented s a l i c i n . A l l 303 Klebsiella cultures produced gas €ran glycerol, 296 promptly fermented i n o s i t o l , 91 d u l c i t o l , 1 7 l i q u e f i e d g e l a t i n , 300 were u r e a -p o s i t i v e and 302 fermented s a l i c i n i n 24 hours.He concluded t h a t g e l a t i n l i q u e f a c t i o n , m o t i l i t y , i n a b i l i t y t o produce g a s from g l y c e r o l , and t o ferment i n o s i t o l , a r e t h e b e s t characters t o i d e n t i f y Cloaca, while d u l c i t o l , s a l i c i n and urea t e s t s may a l s o be useful. H i s c u l t u r e s of Klebsiella included 13 MR-positive s t r a i n s , 12 i n d o l e producers, and 1 VP-negative s t r a i n . C e l l o b i o s e and s t a r c h were not used by Brooke. For t h e urea t e s t he used t h e Christensen medium a s modified by K r i s t e n s e n , w i t h phenol r e d i n d i c a t o r a s recommended by Kauffmann ( 3 ) . Moeller ( 4 )

Studies on the Bacterial Flora of the Alimentary Tract of Pigs. I. Enterobacteriaceae and Other Gram‐negative Bacteria

“…Urease production. This was also determined with both Christensen's urea agar medium (Report, 1958) and the urea medium of Hormaeche & Munilla (1957) incubated a t 37" for 48 hr.…”

“…Arginine and ornithine decarboxylation, and production of arginine dihydrolase. The first, two of these tests were done according to the methods of Moller (1955) and the last by the method of Hormaeche & Munilla (1957).…”

“…Moiler (1955) determined the reaction products derived from arginine by several members of the Enterobacteriaceae and described a peptone-meat extract medium containing pyridoxal and glucose for arginine decarboxylase and dihydrolase production, in which the presence of NH, indicated the action of arginine dihydrolase. Pyridoxal was omitted from the medium in a modification of the arginine dihydrolase test by Hormaeche & Munilla (1957). During the present investigation, the ninhydrin reagent described by Chinard (1 952) has been adapted for the detection of ornithine in cultures grown in the AM medium, and a simultaneous test for NH, has also been carried out.…”

Numerical Taxonomy Study of the Enterobacteriaceae

“…At this point it seemed possible that these characters may have been chosen subjectively by us and, in fact, may give rise to a completely different arrangement if the strains were clustered on only these characters. This possibility was investigated by examining each of the 33 Fig. 6.…”

Membrane Filter Procedure for Enumerating the Component Genera of the Coliform Group in Seawater

“…The use of the urease reaction to differentiate Klebsiella from other coliforms has been used previously by Hormaeche and Munilla (16), Barry et al (2), and Matsen (17). They were at least 93% successful in properly identifying Klebsiella through the use of a urea substrate, tube test performed at 50 C. The test proposed in this study utilizes a low pH which allows Klebsiella colonies to be distinguished from other coliform colonies while they are still on the filter.…”