LIGHT AND ELECTRON MICROSCOPIC STUDIES ON THE MICROFILARIAE OF DIPTALONEMA VITAE DERPKAGORSKAYA, 1923 (NEMATODA: FILARIIDAE) PARASITIZING THE BLOOD OF FRUIT BATS ROUSETTUS AEGYPTIACUS AEGYPTIACUS AT ASSIUT LOCALITY

Dept. of Zoology,

Faculty of Science, Assiut University.

LIGHT AND ELECTRON MICROSCOPIC STUDIES ON THE MICROFILARIAE OF DIPTALONEMA VITAE DERPKAGORSKAYA, 1923 (NEMATODA: FILARIIDAE) PARASITIZING THE BLOOD OF FRUIT BATS ROUSETTUS AEGYPTIACUS AEGYPTIACUS AT ASSIUT LOCALITY

(With 4 Figures)

By

G.H. ABED; R.M. Khalifa*; NAWAL A. Mazen

 and B. Abd-Elmaleck

*Dept. of Parasitology, Fac. of Med., Assiut University, Assiut, Egypt

(Received at 23/3/2005)

دراسات بالميکروسکوب الضوئى والالکترونى على الميکروفلاريا

ديبتالونيما فيتا الذي يصيب خفاش الفواکه روزتيس ايجبتکس ايجبتکس

بإقليم أسيوط

جمال عابد ، رفعت خليفة ،نوال مازن ،برکات عبدالمالک

تناولت الدراسة فحص عدد 179 من خفاش الفواکه روزتيس ايجبتکس ايجبتکس وقد أوضحت الدراسة أن 3 خفافيش فقط بنسبة 7ز1% مصابين بالميکروفلاريا ديبتالونيما فيتا في الدم الطرفي. هـــذا وقد أوضحت الدراسة أن الميکروفلاريا لها نهاية راسية عريضة ونهاية خلفية مدببة وجسمها منحنى ويصل متوسط طولها 187.5 - 202 ميکرون وعرضه ا4-6 ميکرون (202 × 5 ميکرون) وقد أوضحت الدراسة بالميکروسکوب الإلکتروني النافذ أن النهاية الراسية خالية من الانوية أما باقي الجسم فهو ممتلئ بالانوية.

SUMMARY

Out of 179 bats examined only three (1.7%) were infected with the microfilariae of Diptalonema vitae. the microfilariae were encountered in the peripheral blood of Rousettus aegyptiacus aegyptiacus. They are unsheathed and have a broad cephalic end and a blunt posterior end. They measured 187.5–220 mm in length and 4–6 mm in width (average 202 x 5 mm). and the body is a smoothly curved in graceful curves. Transmission electron microscope (TEM) revealed that the cephalic end of the body is devoid from nuclei while the remaining of the body is occupied by a well demonstrated column of nuclei.

Key words: Rousettus aegyptiacus aegyptiacus, microfilaria of Diptalonema vitae, light microscope and tnsmission  electron microscope

INTRODUCTION

Fauna of parasitic nematodes of bats from Egypt was published by Jagerskiold (1909) and Boulenger (1926). Stiles & Nolan (1931) gave the most detailed account of bat nematodes in admirable key catalogue. Galal & Abed (1993) recorded the larval stage of Physaloptera sp,. from Egyptian bats. Esteban et al., (1995) found Physaloptera brevivaginata parasitising the stomach of two species of bats of the family vespertilionidae. The parasite was described as severely pathogenic as histopathological observations of the stomach lesions revealed destruction of the mucosa, degeneration of gastric glands and focal necrosis at the points where cephalic ends of both sexes of this nematode were attached to the mucosa. Foster et al. (1996) reported the same parasite from Brazihian free-tailed bats from Florida. Ammar (2001) redescribed the parasite from the stomach and gut of Taphozous nudiventris nuidiventris and Rhinopoma hardwickei cystops. Abdominal and thoracic cavities as well as the subcutaneous tissue of bats are ideal locations for filaroid nematodes Ammar (2001) described Diptalonema vitae (males, females from subcutaneous tissues and microfilariae from peripheral blood) and Litosoma egyptiacum n.sp. (adults from body cavities) and microfilariae from the peripheral blood.

The present work was aimed to detailed description of the microfilariae of Diptalonema vitae from peripheral blood of fruit bats Rosettus aegyptiacus aegyptiacus from Assiut –Upper Egypt.

MATERIALS and METHOD

Total number of 179 fruit bats Rosettus aegyptiacus aegyptiacus captured from different localities at Assiut Governorate were examined for blood microfilariae through thick and thin blood films stained with Giemsa`s stain.

For transmission electron microscopy studies: Venous blood were collected from infected Rousettus aegyptiacus aegyptiacus. The blood were immediately fixed in 2% glutaraldehyde solution in phosphate buffer (pH 7.2), for 24 hours and, postfixed in 1% osmium tetroxide for 30 minutes. & washed with the same buffer. Dehydrated in ascending grades of ethyl alcohol series and finally embedded in Epon.Semi-thin sections were prepared, stained with toluidine blue,examined by light microscope and photographed. Ultra-thin sections were contrasted with urinyl acetate and lead citrate and examined using transmission electron microscopy (Jeol CXII 100) at   80 kv.

RESULTS

Out of 179 fruit bats Rousettus aegyptiacus aegyptiacus were examined in peripheral blood ,only 3 (1.7 %) were found to be infected withthe microfilariae of Diptalonema vitae  (Fig.1). They exhibited no periodicity, as they were found in blood smears day and night. The microfilaria is unsheathed and they have a broad cephalic end and a blunt posterior end. In fresh blood specimens, they move actively in a worm-like movement in between the red blood corpuscles. They measured 187.5–220 mm in length and 4–6 mm in width (average 202 x 5 mm). The body is smoothly curved in graceful curves (Fig.2), and is occupied by a well-demonstrated column of nuclei which extended to the tip of the blunt tail. However, the cephalic end devoid of nuclei   (Fig. 3).

DISCUSSION

 The incidence of microfilariae in the present work was very low, only 3 specimens of the fruit bats were found to be infected with these parasites. This may be due to the paucity of a suitable vectors in collected zone.

 Filaroid worms belonging to the genus Diptalonema exceed 40 species, but none of them are found in bats except recently where Ammar (2001) encountered for the first time, adults and microfilariae of Diptalonema vitae Drepkagorskaya, 1933 from the subcutaneous tissues and peripheral blood of Taphozous mudiventries nudiventris in Qena Governorate. Diptalonema vitae microfilariae were reported for the first time from naturally infected Rattus norvegicus, Rattus r. frugivorus and Rattus r. alexandrinus collected from the suburban areas from Assiut City by Arafa(1968). Monib (1980) reported the same parasite from the same area in Rattus norvegicus and Rattus r. frugivorus.

 Monib (1980) in his study on parasites of small mammals in Assiut, examined 48 Rousettus aegyptiacus aegyptiacus bats and found them free from any pasasite. He also examined 23 Rhinopoma hardweckei cystops bats where he found them infected only with trematodes and cestodes.

 During the present study, only microfilariae were encountered, but they were very similar to these described by Ammar (2001). Hence, they were identified as belonging to the genus Diptalonema and the species D. vitae Derpkagorskaya, 1933. However, the bat Rousettus aegyptiacus aegypticaus is a new host record and Assiut is a new locality for the parasite.

REFERENCES

Ammar, K.N.A. (2001): Studies on helminth parasites and nematodes infecting bats in upper Egypt. A Thesis Ph.D. Faculity of Science, South Villey University, Egypt.

Arafa, M.S. (1968): Studies on ecto-and endo-parasites of rats and mice in U.A.R. with special reference to parasites potentially transmissible to man. M. D. Thesis Fac. Of Medicine. Ain shams University, Cairo.

Boulenger, C.L. (1926): Reports on a collection of parasitic nematodes mainly from Egypt Part IV. Trichostrongylidae and Strongylidae Parasitology 18: 86– 100.

Esteban-JG., Botella, P. and Toledo, R. (1995): Redescription of Physaloptera brevivaginata Seurat. 1917 (Nematoda: Physalopteridae) from the bat Myotis blythii (tomes) (Chiroptera: Vesspertilionidae) in spain. System. Parasitol. 32: 2, 107-112.

Foster, W.; Garry, and Martins, W. James (1996): Parasitic helminthes and arthropods from Brazilian Free-Tailed Bats (Tadarida brasiliensis cynocephala) in Florida. J. Helminthol. Soc. Wash., 63 (2), pp. 240-245.

Galal, A.A. and Abdel, H.G. (1993): Some parasites of Egyptian bats. Az. J. Pharm. Sci., 12, 122-139.

Jagerskiold, L.A. (1909): Nematoden aus Aegypten und dem sudden (eingesammelt von der schwedischen zoologischen expedition), I. Rictularia und dichelyne. Results of the Swedish zoological expedition to Egypt and the white Nile, 1901, under the direction of L.A. Jagerskiold (K.W. Appelberge, upsala) 3: 1-66.

Monib, M.E.M. (1980): Studies on helminth parasites in some small mammals in Assiut Governorate. A thesis Ph.D. (Parasitology) Faculty of Medicine, Assiut University.

Stiles, C.W. and Nolan, M.D. (1931): Key-catologue of parasites reported for Chiroptera (bats) with their possible public importance. Nat. Inst. Health Bull (155). U.S. Pub. Health Serv. 603 – 742.

EXPLANATION OF FIGURES

Fig.  1: Photomicrograph of the blood smears stained with Giemsa`s stain showing the microfilariae of Dipatalonema vitae (arrow) x 1000

Fig.  2: Photomicrograph of semi-thin section stained with toluidine blue showing the microfilariae of Dipatalonema vitae (arrow head) x 1000

Fig. 3: Transmission electron micrograph showing occupied all the body of microfilariae with nuclei except, the cephalic end of the body devoid of nuclei. (arrows) x10000

Fig. 4: Camera lucida drawing showing microfilariae of Dipatalonema vitae