Antibody response to 'O' antigens of various gram negative organisms isolated from patients with malignant diseases

A total of 349 passive haemagglutination tests were carried out using serum samples from ancer patients against various 'O' antigens prepared from their own body isolates. The n tigens employed were those of eleven different gram negative bacterial species. 94.6% serum samples gave positive tests. Antibody titres obtained ranged from zero to as high as 1:5120, with median titre of 1:80. In contrast, fourteen passive haemagglutination tests were set up using serum samples from healthy individuals against antigens of their own body isolates of which only 50.0% were found to be positive, antibody titres ranging from zero to a low maximum of 1:40, with a median being zero. To test serum samples of healthy individuals against 'O' antigens of patients body isolates, 8 passive haemagglutination tests were set up. Only 21.3% were found to be positive, titres a aging from zero to 1:40, with a median titre o f zero. The results reveal that antibody titre can be .red not only as an index for establishing the immune status of the host but also for discriminating the infecting bacterial species from the colonizing species

Study of opportunistic bacterial species associated with immunocompromised patients suffering from various malignancies

To study the bacterial species associated with infections in immunocompromised patients, samples of sputum, urine and blood from 125 cancer patients at various stages of radiotherapy were studied. Simultaneously similar specimens from 25 healthy individuals were collected to act as controls. Out of 125 patients, gram negative bacterial species were isolated and identified from 58.4% individuals, whereas gram negative bacterial species were isolated from 22.0% healthy individuals only. Eleven species of gram negative organisms were isolated from specimens of sputum, urine and blood of these patients. In contrast, only four different gram negative bacterial species were isolated from the group of healthy individuals. Escherichia coli was the organism most frequently isolated from both sets of individuals. The data obtained were also analysed to reveal the frequency of opportunistic gram negative bacterial species at various stages of therapy, as well as their correlation with the clinical samples. It was seen that gram negative opportunistic bacteria were mostly isolated during post-treatment stage of therapy. The highest number of patients yielded gram negative opportunistic bacteria from their sputum samples