Macap Fill 2834(9).qxd Introduction Rats and mice harbor a number of helminth parasites, which can be transmitted to man and other vertebrates (Oldham, 1931). Helminth parasitized rats were studied to identify the species and for determination of prevalence and intensity of helminths (Stanly and Virgin, 1993; Alam et al., 2003; Khanum and Arefin, 2003). Cestode and nematode parasites in rat have been reported from all parts of the world. Vampirolepis nana and Hymenolepis diminuta are commonly found in rats and mice and potentially transmissible (Zoonoses) to man. The occur- rence of H. diminuta and V. nana in certain rodents is of interest since the possibility exists that rats and mice may serve as reservoir hosts and aid in the dissemination of these worms to domestic animals and man (Jawdat and Mahmoud, 1980); causing zoonoses. In Bangladesh, several studies have been carried out on iden- tification of the parasites of rats and mice but no histopotho- logical investigation have been done (Huq, 1969; Shaha, 1974; Bhuiyan et al., 1996; Alam et al., 2003 and; Khanum and Arefin, 2003). The effects of parasites on their host can also be examined by pathological condition. Inspite of sev- eral pathological works on parasitic infestation in our coun- try no pathological investigation have so far been undertaken on histopathology of the infes- tation on Long-Evans. The present study was carried out on identification of para- site species prevalence and histopathological effect of para- sites on their host and for securing additional information on the helminth parasites of laboratory rat. Materials and Methods During the study period from April 2007 to March 2008 a total of 48 Long-Evans were collected weekly and monthly basis from Animal Research Section of the Institute of Food Science and Technology (IFST) of Bangladesh Council of Scientific and Industrial Research (BCSIR), Dhaka. To col- lect the parasites tested Long-Evans were dissected, the vis- cera were collected and brought to the parasitology laborato- ry of the Department of Zoology, University of Dhaka. A histopathological investigation was carried out on thin sec- tions of tissues. Then permanent slides were prepared from the tissues and permanent slides were prepared by Cable, 1963. Nematode and Cestode Prevalence, Organal Distribution and Histological Effects Due to Parasitic Infection in Laboratory Rat Strain, Long-Evans (Rattus norvegicus Berkenhout, 1769) Hamida Khanuma , Farhana Muznebina* and Zaibun Nessab aDepartment of Zoology, University of Dhaka, Dhaka-1000, Bangladesh and bInstitute of Food Science and Technology, BCSIR, Dhaka-1205, Bangladesh. Abstract Endoparasitic infection and histopathological effects in the laboratory rat, Long-Evans (Rattus norvegicus Berkenhout 1769) was evalu- ated. Five species of helminth parasites from two taxonomic groups were identified. They were -Cestodes (Vampirolepis nana Siebold, 1852 and Hymenolepis diminuta Rudolphi, 1819) and Nematodes (Citellina dispar Prendel, 1928; Heterakis spumosa Schneider, 1866 and Syphacia muris Yamaguti, 1941). All the worms were collected from the alimentary tract of the Long-Evans. The prevalence of infection was found highest in caecum (95.83%) and the intensity of infestation was found highest in anterior parts of the intestine (51.33±10.63). The histopathological study of helminth infected alimentary canal showed that the intestinal wall was severely damaged. Key words: Nematodes, Cestodes, Prevalence, Vampirolepis nana, Hymenolepis diminuta, Citellina dispar, Heterakis spumosa and Syphacia muris. Bangladesh J. Sci. Ind. Res. 44(2), 207-210, 2009 BCSIR Available online at www.banglajol.info BANGLADESH JOURNAL OF SCIENTIFIC AND INDUSTRIAL RESEARCH E-mail: bjsir07@gmail.com *Corresponding Author, Email: farhana_zoologydu@yahoo.com. 208 Nematode and Cestode Prevalence, Organal Distribution 44(2) 2009 Results and Discussion The intestine of the Long-Evans (Rattus norvegicus) was infested by cestode parasites Vampirolepis nana (Siebold, 1852) and Hymenolepis diminuta (Rudolphi, 1819) and nematodes Citellina dispar (Prendel, 1928); Heterakis spumosa (Schneider, 1866) and Syphacia muris (Yamaguti, 1941). A total of 1643 nematodes were collected from 46 infested hosts and 1911 cestodes from 38 infested hosts. The preva- lence of cestodes and nematodes were 79.17% and 95.83% respectively. Prevalence of nematodes was higher than the cestodes. Intensity of cestodes and nematodes were 50.29 ±14.13 and 35.71 ±7.89 respectively. The parasites were most abundant in anterior part of intes- tine. No parasites were found in stomach. In duodenum 46 (43.75%) parasites were collected and 1848 (75%) parasites were collected from anterior intestine, 729 (77.08%) para- sites from posterior intestine and 931 (95.83%) parasites were collected from caecum. Lower intensity of infestation was found in duodenum (2.19 ±0.42). The highest inten- sity was found in anterior intestine (51.3±10.63). Slightly higher intensity of infestation was found in caecum (20.23±2.60) and in posterior intestine (19.70 ±2.37) respec- tively (Table I). In species mix distribution the highest prevalence of V. nana was recorded from anterior intestine (53.33%). While, lower prevalence was found in duodenum (41.66%). The highest prevalence of H. diminuta was found also in anterior intes- tine (50%). The lower prevalence was recorded in duodenum 4.16% and in posterior intestine (4.17%). But duodenum and caecum contain higher and equal prevalence (20.83%). On the other hand, 0% prevalence was found in stomach, duode num and anterior intestine in case of C. dispar, H. spumosa and S. muris. The highest prevalence of C. dispar was found in caecum (60.42%) and comparatively lower in posterior intestine (52.08%). But the highest prevalence (62.50%) was found in caecum both in case of H. spumosa and S. muris. The lower prevalence of them was found in posterior intes- tine 39.58% and 54.17% respectively. The intensity of V. nana showed the highest intensity in ante- rior intestine (61.71) while, parasites were totally absent in stomach, posterior intestine and caecum. Lower intensity was found in duodenum (2.2). The highest intensity of H. diminuta was found in anterior intestine (5) and lower inten- sity (1) was found in duodenum, posterior intestine and cae- cum. The highest intensity of C. dispar and S. muris were found in caecum (11.79 and 13.83) and slightly lower inten- sity was found in posterior intestine (9.88 and 13.42). H. spumosa was showed the highest intensity in posterior intes- tine (6.84) and comparatively lower intensity were found in caecum (5.33) (Table II). The intestine of Long-Evans is a coil and long tube and its wall is consists of serosa, muscularis, submucosa and mucosa. These layers are arranged serially one below the other. The muscularis consists of thick circular and thin lon- gitudinal muscle layer. The parasites were found firmly attached to the intestinal wall with their adhesive organs bearing gland cells or hooks by which they remain attached to the host mucosa. The parasites damaged the walls at the sites of their attachment. This disruption was mainly due to the action of sucker of helminth parasites. As a result the intestinal wall was heavily destroyed. In some cases, tissues were found to disappear completely (Fig. 1-3). Thus vacular structure appeared. Fibrosis or necrosis and few pigments were also observed. Table I. Organ wise prevalence and intensity of helminth parasites in Long-Evans. Organ Total no. of Total no. of Prevalence Total no. of Intensity hosts examined hosts infected (%) worms collected (± SD ) Stomach 48 0 0 0 0 Doudenum 48 21 43.75 46 2.19 ±0.42 Ant. Intestine 48 36 75 1848 51.33 ±10.63 Post. Intestine 48 37 77.08 729 19.70 ±2.3 Caecum 48 46 95.83 931 20.23 ±2.60 Table II. Prevalence and intensity of organ wise each species of helminth parasites in Long-Evans. Organ V. nana H. diminuta C. dispar H. spumosa S. muris No.of hosts infected 20 2 0 0 0 No. of worms collected 44 2 0 0 0 Doudenum Prevalence % 41.66 4.16 0 0 0 Intensity 2.20 1.00 0 0 0 No.of hosts infected 28 24 0 0 0 No. of worms collected 1728 120 0 0 0 Ant. Intestine Prevalence % 53.33 50.00 0 0 0 Intensity 61.71 5.00 0 0 0 No.of hosts infected 0 2 25 19 26 No. of worms collected 0 3 247 130 349 Post. Intestine Prevalence % 0 4.17 52.08 39.58 54.17 Intensity 0 1.50 9.88 6.84 13.42 No.of hosts infected 0 10 29 30 30 No. of worms collected 0 15 342 160 415 Caecum Prevalence % 0 20.83 60.42 62.50 62.50 Intensity 0 1.50 11.79 5.33 13.83 Total number of host examined was 48, No parasite was found in the stomach. Khanum, Muznebina and Nessa 209 Khanum and Arefin (2003) reported that in laboratory mice the prevalence of infestation was highest in anterior intestine (70.5%) and the lowest in stomach (5.83%). The intensity of infestation in laboratory mice was found lowest in duode- num and the highest in anterior intestine. From the above investigation indicates that the intestine and caecum is the favorite niche of most parasites where they were heavily abundant. Abundance of V. nana was highest in anterior part of the intestine (small intestine) in Long-Evans in present observa- tion supports Jawdat and Mahmoud (1980) who also found similar distribution. From histopathological investigation it was observed that, the intestine was affected and tissues were damaged serious- ly by V. nana and H. diminuta. Degenerated tissues were observed within the folds around the parasites. The muscu- laris mucosa was found to be disrupted and damaged by the parasites. Disrupted tissue of Mucosa Fig 1. Transverse section of infected intestine of Long- Evans (40 x 10). Hemorrhages and lesion of villi Fig 2. Transverse section of infected intestine of Long-Evans (40 x 10). 210 Nematode and Cestode Prevalence, Organal Distribution 44(2) 2009 Conclusion The histopathological observation showed that the presence of parasites within the organs causes hazard to the host in many ways. Heavy infection to the intestine may cause per- foration and thereby physiological function might be abnor- mal. Damage of villi tissues may cause many reactions to the host. Acknowledgement The authors wish to offer thanks to Dr. M. Formuzul Haque, Ex. Director, IFST, BCSIR, Dhaka for providing laboratory facilities during the research work. The authors are indebted to Dipa Islam, Scientific Officer, IFST, BCSIR, Dhaka, for her co-operation and helpful guidance. The authors are also grateful to M. Abdur Razzak, Senior Laboratory Attendant, Animal Research Section, IFST, BCSIR, Dhaka for his assis- tance during this research. References Alam M. S., Khanum H., and Nessa Z. (2003) Helminth infection in laboratory rat strain, Long-Evans (Rattus norvegicus Berkenhout, 1769). Bangladesh J. Zool. 31(2): 221-225. Bhuiyan A. I., Ahmed T. A., and Khanum H. (1996) Endoparasitic Helminths in Rattus rattus Linnaeus and Bendicota bengalensis Gray. J. Asit. Soc. Bangladesh, Sci. 22: 189-194. Cable R. M. (1963) An illustrated laboratory manual for Parasitology. Burgress Publishing Company, Minneapolis. PP. 169. Huq M. M. (1969) A survey of the helminth parasites of roof rats Rattus rattus, digger rats Bendicota ben- galensis and mole Scalopus scalopus in Mymensingh district, East Pakistan. Pak. J. Vet. Sci. 3: 65-68. Jawdat S. Z., and Mahamoud S. N. (1980) The incidence of cestoidean and acanthocephalan parasites of some rodents in Iraq. Bull. Nat. Hist. Res. Centre. 7(4): 55-71. Khanum H., and Arefin N. (2003) Helminth Burden in Laboratory mice, Mus musculus. Bangladesh J. Zool. 31: 117-123. Oldham J. N. (1931) The helminth parasites of common rats. J. Helminth. 9: 49-60. Shaha J. G. (1974) Taxonomy of some of the helminths of house rats, house mice and house shrews of Dacca city. M. Sc. thesis. University of Dhaka, Bangladesh. PP. 120. Stanley S. L. J. R., and Virgin, I. V. H. W. (1993) Scid as models for parasitic infections. Parasitol Today. 9: 406- 411. Received : September, 03, 2008; Accepted : December, 18, 2008 Fig 3. Transverse section of infected intestine of Long- Evans (40 x 10). Destructed and damaged mucosa and submucosa layers Jahangir, Mondal, Nada, Sarker, Moniruzzaman and Hossain. 6 Response of Different Level of Nitrogen and Phosphorus 44(2) 2009