Haemagglutination, haemolysin production and serum resistance of proteus and related species isolated from clinical sources.

A total of 148 strains of Proteus and related species comprising of Proteus mirabilis (116), Proteus vulgaris (24), Providentia rettgeri (4), Providentia alcalifaciens (2), Providentia stuarti (1) and Morganella morganii (1), isolated from various sources, were examined for haemagglutination (HA), haemolysin production (HL) and serum resistance (SR). Maximum isolates were obtained from urine (47.30%) and pus (40.54%) and they were multidrug resistant. The sensitivity to Ciprofloxacin was 78.38%, Gentamicin: 62.84%, Cefotaxime: 29.73%, Norfloxacin: 22.97%, Tetracycline: 20.95% and Ampicillin: 6.76%. There were four commonest resistance patterns shown by 58.62% of Proteus mirabilis and 66.67% of Proteus vulgaris strains. Haemagglutination was shown by 91 (61.49%) strains, HL production in 126 (85.14%) strains and SR by 124 (83.78%) isolates. All the three i.e. HA, HL and SR were simultaneously present in 77 (52.27%) strains, any two were present in 40 (27.03%) strains and any one was positive in 30 (20.03%) strains. Thus in as many as 147 (98.32%) isolates, any one or more virulence factors were present. The virulence in commensal pathogen like Proteus is basically a multifactorial phenomenon. The presence of more virulence factors in one strain may increase its pathogenic ability. The evaluation of multiple virulence factors instead of one single parameter will be of greater help in assessing its pathogenic potential.