Study of some virulence factors in Proteus sp. associated with diarrhea

Abstract

Various virulence factors including protease, lipase, lecithinase, deoxyribonuclease, gelatin liquefaction, haemolysin, congo red binding and urease production were determined for 94 Proteus isolates recovered from stool specimens of 518 children suffering from diarrhea. Eighty six (91.5%) of these isolates were belong to Proteus mirabilis and 8 (8.5%) were Proteus penneri. The results showed that the distribution of virulence factors was variable among the tested isolates. All isolates 94 (100%) were urease producers' but have different ability for binding to Congo red, gelatin liquefaction, deoxyribonuclease, lipase, protease, lecithinase, and haemolysin production. In order to study the invasion character, mice (Balb/c) infants were sucked with the suspension of (1) selected virulent isolate of Proteus mirabilis (positive for all the virulence factors), histological sections were performed to study the mode of the entry of bacteria into the enterocytes, and the histological changes in the liver. Microscopical examination for histological sections showed pathological effect on two organs when compared with the control organs. The results give clear evidence that Proteus mirabilis more virulent than Proteus penneri.