抄録
Biochemical studies on Aerobacter cloacae have been carried out by many workers. Recently, according to the advanced opinion and definite judgment of Edwards, A. aerogenes was classified into the Klebsiella group (Kauffmann, 1951) and A. cloacae into the Cloaca group of Castellani and Charmers (Kauffmann, 1954) . On the other hand, Edwards and Fife (1955) proposed to name the group “Aerobacter ”, since the name Aerobacter has been more commonly used than the name Cloaca and Aerobacter could not be clearly separated from Klebsiella. The present authors (1957) reported that typical Cloaca cultures in amino-acid decarboxylation tests were differentiable from Klebsiella and other similar cultures by means of biochemical tests.
In spite of its distinct biochemical properties, serological studies so far performed on. this group gave only unsatisfactory results. Edwards and Fife (1955) described that, among A. cloacae cultures studied, a half of them were encapsulated, 30% of the latter being typable with Klebsiella capsular sera. The authors (1957) concluded, however, that the organisms of the Cloaca group were generally acapsulated and definitely differed from. encapsulated motile Klebsiella-like organisms in amino-acid decarboxylation and sugar fermentation tests. Stuart, Wheeler, Rustigian and Zimmermann (1943) studied the former organisms biochemically and serologically by the name of paracolon Aerobactern without any account for O and H antigens of the organisms. Deacon (1952) found 12 O and 6 H antigens in the cultures of biotype 32011, which had been described by Stuart and his co-workers, and other related cultures of slowly lactose-fermenting A. cloacae by antigen analysis. Eveland and Faber (1953) also studied biotype 32011 serologically and established 21 O and 22 H antigen groups. However, it was assumed by Edwards and Ewing (1955) and confirmed by the authors (1957) that biotype 32011 belonged to the Hafnia group but not to the Cloaca group. Therefore, any of the serological studies made in the past can not afford information for establishment of the systematic serology of the Cloaca group,
The present studies were carried out to obtain sufficient information on the serological characteristics of the Cloaca organisms.
