EN
One month old male Wistar rats were infected with 4,000 T. spiralis muscle larvae and exposed to intraperitoneal challenge with a lyophilized cell wall extract of Propionibacterium granulosum. The animals were arranged in groups which included naive controls, single and concurrent treatment. The latter comprised several groups differing only in the interval between infection with T. spiralis and administration of the bacterial extract. The intensity of infection was assessed during the intestinal (5 DAI, 10 DAI) and muscle (42 DAI) phases of infection, fecundity indices were calculated and changes in the relative concentration of peripheral blood leucocytes, erythrocytes and haemoglobin levels were monitored. No changes in erythrocyte concentration were detected in groups treated with the immunomodulator and infected with T. spiralis, but increased leucocyte counts, haematocrit and haemoglobin levels depended on the time of treatment in relation to infection and day on which the parameters were monitored. All rats treated with the bacterial extract had lower adult worm counts but harboured worms with enhanced fecundity relative to the control group. The intensity of the muscle phase was lower only in those groups treated with the bacterial extract after nematode infection.