Klebsiella pneumoniae 35 and 36 kDa porins are common antigens in different serotypes and induce opsonizing antibodies

Background. Klebsiella pneumoniae is a major cause of neonatal sepsis and n osocomial infections in Mexico. Antibiotic therapy is the first choice for treatment hut the increase in multiple resistance strains has forced scient ists to look for alternative treatments. such as immunotherapy. In this wor k, we propose that pol ins could be a common antigen among four different c apsular serotypes of Klebsiella pneumoniae for the production of immune ser a with opsonizing capacity. Methods. The 35 and 36 kDa porins from four different serotypes of the bact eria were isolated by the Nikaido method followed by purification in Sephac ryl column chromatography. The 36 kDa of serotype K8 was further purified b y electroelution. The 35 and 36 kDa porins were used to obtain rabbit polyc lonal antibodies (PolyAb) to the four serotypes and the 36 kDa from KS for the production of monoclonal antibodies (MoAb). Antigenic reactivity of Pol yAb and MoAb were analyzed by ELISA and WB and their opsonizing capacity fo r human PMN was measured by chemiluminescence (CL) using capsulated and non capsulated bacteria. Results. Porins from the four strains showed electrophoretic homology and c ross reaction by ELISA and WE. CL assays indicated that PolyAb opsonized he terologous strains and that MoAb perform this in the absence of capsule. Conclusions. K. pneumoniae 35 and 36 kDa porins are common antigens for the four se retypes studied and induce opsonizing antibodies. (C) 2000 IMSS. P ublished by Elsevier Science Inc.