Proteus

The genus Proteus belongs to the family Enterobacteriaceae. It is a Gram-negative facultatively anaerobic bacteria characterized by a swarming phenomenon.

General characteristics
It is a genus of bacteria with considerable mobility, which is made possible by the presence of several flagella. It differs from other enterobacteria in its ability to deaminate some amino acids to ketoacids and ammonia. They produce hydrogen sulfide and have significant proteolytic activity, breaking down organic matter in garbage. A very specific property that can be observed during cultivation is swarming on the blood agar surface in the form of concentric rings (the so-called Rauss phenomenon). It also grows on Endo agar. They are commonly found on plants, in soil, or in faeces and is usually transimtted in the fecal-oral way (though the transmission is mostly endogenic). They are also human pathogens – common agents of urinary tract infections (especially P. mirabilis), where the released ammonia irritates the mucous membranes and alkalinizes the urine, which can contribute to the formation of urinary stones. They can also cause secondary infections in wounds or decubitus. The entire genus has increased resistance to some disinfectants and includes 8 species, with P. vulgaris and P. mirabilis being particularly important.

Therapy
The antibiotics of choice for Proteus spp. are usually cephalosporins of 1st and 2nd generation for P. mirabilis, eventually nitrofurantoin for P. vulgaris. Generally, the genus became resistent to colistine and tetracyclines.

Proteus mirabilis
Proteus mirabilis is probably the most important species of the genus Proteus. It is one of the common pathogens causing urinary tract infections.

Proteus vulgaris
Proteus vulgaris is a slightly less common representative of the genus. It is commonly isolated from wound infections and can cause disease in immunosuppressed patients.

Related articles

 * Proteus mirabilis
 * Escherichia coli
 * Salmonella
 * Vibrio
 * Urinary tract infections