Technologies Developed

1. Infecting large animal. Infecting large animals by percutaneous method (Rabbit, Sheep, Goat, Pig, Cattle etc.) with schistosome cercariae for experimental work on chemotherapy, pathology, immunology or any other purpose has always been difficult. It required control of the animals with the use of sedatives and was much time consuming as individual animal has to be handled else there were chances of spoilage of the cercariae.
We have observed that the schistosome cercariae survive in the water with full biological activities even if kept in a polythene bag. This prompted us to put counted number of cercariae in polythene bag and tie it in paw of the Guinea pigs. To our surprise, all the cercariae penetrated the paw skin and the guinea pigs developed the infection. We repeated this technique by using ear pinna of the rabbit, tail of the pigs , and ear pinna of the goats. In all these animals, the schistosome infection developed with recovery of blood flukes which was not different from that of traditional method

2. Perfusion of animal. Recovery of the Schistosomes from killed animals is important either for confirming diagnosis or assessing chemotherapy, immunology or any other parameter on schistosomiasis. For accurate fluke recovery, a perfusion technique is always recommended which is being carried out by a peristaltic pump or any other such device.
In India we have used first time perfusion technique for recovery of the blood flukes . In the technique one automatic pipetting machine was used for perfusing the animals.This was suitable only for small animals and resulted in breaking of glass syringes due to neglect. Therefore, it is felt if automatic pipetting machine can be replaced by any other simple device or equipment. The trials with horizontal water pump commonly used in desert water coolers proved successful. Thus the technique showed two clear cut advantages over automatic pipetting machine.

(a) While automatic pipetting machine was useful only in rat & mice, the new technique with water pump was useful in all the animals of all sizes.

(b) The cost of horizontal water pump is only Rs. 600/- while that of automatic pipetting machine or peristaltic pump is 30,000=00 to 80,000/-.


3. Use of polythene bag. All over the world ,all the medical & veterinary Diagnostic laboratories are examining faecal samples for parasitic infections by using micro slide & cover slip. This traditional technique inherits following disadvantages.

(a) The slide dries up within one hour and it is important to check the sample within stipulated period.

(b) The slide cannot be kept as reference material as it spoils within a day or so. The slide cannot be dispatched outside the city by ordinary mail for taking second opinion of another expert. The cost of slide & cover slips is more than Rs. 1.5 /-

(c) We thought to device some simple technique which may rectify the above problems.
At last we were successful when processed faecal material was kept in small LDPE polythene bag whose opening end was sealed with an electric rod. We can observe all the helminthic eggs as well as protozoan cysts under microscope using 100, 400 magnification. The polythene bags may be stored for about a month and may be transported to any place by ordinary post. Additionally the cost of the polythene bags is not more than 25 paise.

4. Biological Control of fresh water Snails. Fresh water snails (Indoplanorbis exustus, & L.luteola and L. accuminata) are responsible for transmitting almost all fluke infections in India.Therefore, it is important to search out any biological control agent for these fresh water snails.

During our work, we developed a simple technique of keeping fresh water snails in the artificial pond.The conditions were simulating to natural conditions. The methodology was quiet well for 2 years. But after wards we observed diminishing number of snails and no new snails were coming up. A thorough investigation to the problem for about a year , revealed that one wingless aquatic insect was responsible for eating young snails.

The insects were carnivorous and feeding on snails under natural conditions. These were identified as nymphs of the dragon fly. Our repeated work have shown that these nymphets breed & develop favorably in the aquatic environment which is also favourable for the fresh water snails. Since both the organisms are surviving in the same environment ,it will be more feasible & appropriate to develop nymphets as biological control agent for the fresh water snails. These nymphets are known to feed on mosquito larvae/ pupae ( we have confirmed the same) and other insects. However, feeding on fresh water snails appears our original observation. The work may be explored further for control of fluke infections. We may provide consultancy on this subject.