The feeding mechanism of intracellular muscle larvae trichinella nativa and trichinella pseudospiralis
Hulinska, D.; Grim, M.; Shaikenov, B.
Folia Parasitologica (Ceske Budejovice) 32(1): 61-66
The EM confirms that Trichinella larvae feed directly on the host [mouse] tissue during their initial development. They suck, by using a stylet acting as a piston, all components of the muscle cell which develops into a nurse cell into their oral cavity. The stylet is controlled by a muscle retractor. At day 10 p.i. [postinfection] fragments of myofilaments and glycogen are present in the esophagus of the larva of T. nativa, mitochondria occur in it at day 20 p.i. During the larval growth of T. pseudospiralis, remnants of a contractile material are present in the digestive system. The composition of the food ingested by the larva is in agreement with the development of changes in the muscle fiber. Initial changes in the fiber caused by the 2 Trichinella spp. are comparable; later changes are not. T. pseudospiralis influences the character of changes by its uninterrupted movement inside the fiber. From days 50-90 p.i. with T. pseudospiralis, a focally distributed sarcotubular system proliferates irregularly in different sites of the fiber. This is in contrast to a heavy proliferation of tubules inside a concentric membranous system around the larva of T. nativa becoming enclosed in a capsule. The larva which has ceased to feed on the host tissue of this time feeds apparently on low-molecular substances of the membranous system transported from the surrounding vascular system which has increased in quantity in the endomysium. In the later course of the infection, the enzymatic activity increases in the vicinity of the larva of T. nativa, i.e., in the sarcoplasm inside the capsule. In an infection with T. pseudospiralis, the focally distributed succinic dehydrogenase activity is high in the entire fiber from the start of the infection.