Molecular identification of diarrheal using immuno magnetic polymerase chain reaction (IM-PCR) technique: a comparative study with conventional culture method.

BACKGROUND

are ubiquitous bacteria causing many clinical conditions including acute diarrhea. Diarrheagenic harbors aerolysin gene secreting virulent enterotoxin, aerolysin.

OBJECTIVES

To develop a molecular and immunological based method for detection of .

METHODS

Diarrheal strains were identified from stool samples using culture, enterotoxicity testing using mice model. During immune magnetic polymerase chain reaction IM-PCR protocol, aerolysin specific antibodies were bound with immuno magnetic binding. Sensitivity and specificity tests for IM-PCR were conducted.

RESULTS

There was high detection of using IM-PCR (12.4 %) technique when compared to low isolation with culture (5.1%). Our study confirmed that some strains of enterotoxic strains were uncultivable. Enterotoxicity tests on culture isolates revealed many strains were negative. IM-PCR detected high, (62/500) rate of identification of Aeromonas with aerolysin toxin gene. species identified after IM-PCR were A. hydrophila (40.3% ), A. veronii (17.7 %), A. caviae (14.5 %), A. trota (11.2 %), A. jandei (9.6 %) and (6.4%). All strains were undetected by cultivation.

CONCLUSION

High sensitivity and specificity of IM-PCR are due to preparation of aerolysin antibodies and immuno magnetic binding, prior to PCR. Since diseases due to are increasingly reported, IM-PCR is recommended for detection from clinical specimens.