GROWTH AND DEVELOPMENT OF BRUGIA-PAHANGI LARVAE UNDER VARIOUS INVITROCONDITIONS

In vitro culture methods were utilized to investigate specific nutriti onal requirements of Brugia pahangi larvae. Infective third-stage larv ae (L.) isolated from Aedes aegypti (Liverpool) mosquitoes were cultur ed in NCTC 135:IMDM (NI) medium plus various types of serum under 5% C O2/air and 5% CO2/N2 atmospheres. Larvae grew, developed, and molted t o the fourth stage (L4); however. further growth and differentiation b eyond the mid-L4 were minimal. Serum supplementation was necessary to induce molting of B. pahangi L3s. Iron-supplemented calf serum (FeCS) consistently promoted higher percentages of molting than the other 4 t ypes of serum tested. Specific nutritional requirements for B. pahangi larvae were assessed through testing of supplements known to be impor tant for growth of mammalian cells or other parasites in vitro. Additi on of various concentrations and combinations of hemoglobin, insulin, transferrin, selenium, albumin, cholesterol, or a cell feeder layer di d not improve larval growth, molting. or survival compared to that obt ained with FeCS alone. The L4s derived from in vitro culture, when inj ected intraperitoneally into jirds, developed to sexually mature, micr ofilarial-producing adults in a normal in vivo time frame. Developing L4s isolated from jirds molted to young adults in vitro in NI medium p lus serum.