CHAPTEK 27 

 PROTEUS AND ZOPFIUS 



PROTEUS 



Definition. — Proteus. 



Highly pleomorphic rods, filaments and curved cells being common in young 

 cultures. Gram -negative. Actively motile. Characteristic spreading growth on 

 moist media. Often Uquefy gelatin and often produce vigorous decomposition 

 of proteins. Ferment glucose and usually sucrose, but not mannitol or lactose, 

 with production of acid and gas. 



Tjrpe species. P. vulgaris Hauser. 



Habitat.^ — Organisms of the Proteus group have been known since the earliest 

 days of bacteriology. They are widely distributed in nature, and constitute an 

 important part of the flora of decomposing organic matter of animal origin. They 

 are constantly present in rotten meat and in sewage, and very frequently in manure. 

 Though often demonstrable in the faeces of man and animals, they are rarely found 

 in large numbers except when the normal intestinal mechanism is deranged. 

 They are not uncommon in garden soil and on certain vegetables, such as melons 

 and celery (Cantu 1911), but it seems probable that their access to these materials 

 results largely from contamination with sewage or manure. 



Besides their wide saprophytic existence, Proteus bacilli are able under certain 

 conditions to grow in the animal body and even to give rise to pathological disturb- 

 ances. The role they play in summer diarrhoea is not yet entirely clear, but there 

 is no doubt that in some outbreaks of this disease they multiply enormously in the 

 intestinal canal, particularly of infants. This holds particularly true of Morgan's 

 bacillus which, in the light of Rauss's (1936) recent work, must be regarded as 

 belonging to the Proteus group. They are primarily responsible for some cases of 

 cystitis, and they are to be met with as secondary invaders in infections of the 

 bladder and in wounds. Many strains, referred to as Proteus X strains, have been 

 isolated from the urine, faeces, or blood of patients suffering from typhus fever, 

 though their exact relationship to the aetiological agent of this disease is still obscure 

 (see Chapter 83). 



Morphology. — The organisms are rod-shaped, but are subject to great variation 

 in size. In agar cultures after 24—48 hours, the majority are of the coliform type, 

 1-3 ju long by 0-4-0-6 jli wide, though short fat cocco-bacillary forms are not un- 

 common (Figs. 136, 137). In young rapidly growing cultures, however, in which 

 swarming (see p. 643) is apparent, many of the organisms are long, curved, and 

 filamentous, reaching 10, 20, or even 30 pi in length (Fig. 135). There is no very 

 characteristic arrangement ; the bacilli are distributed singly, in pairs, in short 

 chains, in small bundles, or in larger bundles in which the members tend to be 

 arranged concentrically, more or less simulating the isobars in a diagram of a 



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