Studies on the pathogenicity of classical enteropathogenic Escherichia coli strains isolated from acute diarrhoea among children 0-5 years of age.

The mechanisms of pathogenicity in EPEC strains were studied in tissue culture. Escherichia coli was isolated as the predominant organism in the primary culture of 1293 (70.54%) diarrhoeal cases. 284 (90.44%) cases from the age group of 1-6 months showed Escherichia coli as the predominant organism. Classical Enteropathogenic Escherichia coli) were detected in 311 (24.05%) cases. Among EPEC isolates 277 (89.06%) did not produce either LT or ST 32(10.28%) produced LT or ST. 2 strains produced verotoxins belong to serotypes 0:86; K:61, 0:26; K:60, sero groups 0.86 :K:61, 0.142:K 86, 0.128:K 67, 0.126:K 71, 0125:K 70 0119:K69 showed localised adherence and serogroups 0111:K58-055:K59 showed both localised and diffused adherence to HeLa cells.

A simple method to quantitate circulating immune complexes in different diseases.

Immune Complexes are involved in the Pathogenesis of many diseases of varied aetiology such as autoimmune disorders, protozoal diseases, bacterial and viral infections. Quantitation of immune Complexes in these diseases can be used for diagnosis and to ascertain the prognosis. The simple method of precipitation by polyethylene glycol and quantitation by single Radial Immunodiffusion has been used in leprosy, syphilis, bacterial endocarditis and systemic lupus erythematosus (SLE). This method found significantly higher levels of circulating immune complexes (CICs) in erythema nodosum leprosum, culture positive bacterial endocarditis and SLE where CICs are known to play an important role in the pathogenesis.

Differential diagnosis of viral hepatitis based on hepatitis viral markers.

192 patients of acute viral hepatitis (AVH) from three different hospitals of Madras metropolitan area during November 1985 to January 1986 were investigated for serologic markers of hepatitis A virus (anti HAVIgM) and hepatitis B virus (HBsAg, HBeAg, anti HBcIgM and anti HBs) by Enzyme linked immunosorbent assay (ELISA). While the overall pattern of AVH in Madras as revealed from the study showed Hepatitis A to be 36.4%, Hepatitis B 34.4% and Non-A Non-B 29.1%, the pattern differed significantly when areawise categorisation was done. The major AVH type in Government General Hospital was Hepatitis B (48.9%). While it was hepatitis A (46.9%) in Government Stanley Hospital and Non-A Non-B (40.0%) in Military Hospital. Using anti HBcIgM marker of Hepatitis B Virus and anti HAVIgM it was possible to make out that 13.5% of the cases, currently suffering from hepatitis A were either HBV carriers (8.3%) or cases convalescing from a previous Hepatitis B attack (5.3%). Various combinations of HBV markers positivity were observed and their diagnostic significance inferred.