Scolices Of Echinococcus Granulosus Research Articles

Hydatid Cyst of Inferior Rectus.

A 34-year-old male, presented with a three-month progressive decrease in visual acuity and chemosis in the left eye. The patient had limitation in ocular motility, proptosis, and chemosis of conjunctiva in left eye (A). MRI demonstrated a localized, circumscribed lesion that was homogenously hypo-intense in sagittal and coronal T1 images (B and C, respectively). The inferior rectus muscle fibers were carefully dissected through an inferior trans-conjunctival incision, until the cyst was revealed. The content of the cyst cavity was aspirated, irrigated by a 15% hypertonic saline solution, and re-aspirated carefully; Then, the cyst was resected completely (D). Histopathologic examination showed a laminated membranous cyst wall (arrowhead) with inner germinal layer (arrow) and scolices of Echinococcus granulosus (double arrow), pathognomonic for hydatid cyst (E). Systemic Albendazole (400 mg twice daily) and Praziquantel (40 mg/kg per day) were prescribed for 2 weeks before operation and continued 3 months after the surgery. There was no clinical evidence of recurrent disease in a 24-month follow-up. Hydatid cyst of the inferior rectus muscle is a rare entity among orbital intramuscular masses, even in endemic regions. Preoperative suspicion is essential to prevent complications during and after surgery.

Delayed cerebral vasospasm and systemic inflammatory response syndrome following intraoperative rupture of cerebral hydatid cyst

Dear Editor, Treatment for symptomatic cerebral hydatid cyst is usually surgical excision. Surgery for cerebral hydatid cyst remains tricky, as inadvertent rupture may cause dissemination and occasionally allergic shock [3]. We report an unusual complication of delayed cerebral vasospasm and systemic inflammatory response syndrome (SIRS) following intraoperative rupture of hydatid cyst. A twenty-two-year old male presented with bifrontal headache for 5 years that worsened over the last 4 months, along with vomiting and left brachio-facial weakness in the last 1 month. Radiology revealed multiloculated large cystic lesion in the right temporal lobe, with the cyst walls partly enhancing (Fig. 1a–d). The lesion was approached through middle temporal gyrus, and multiple white translucent cysts were encountered, adhered to the medial temporal lobe and tentorium. Though the cysts were excised completely, there was some spillage of fluid from the inadvertent rupture (due to adhesions) of the first cyst into the cisternal spaces. Thereafter, 10 % betadine-soaked gauze was put over the operative cavity for 30 min, followed by thorough saline lavage. The cyst fluid showed scolices of echinococcus granulosus with several protoscolices and hooklets. The immediate pos operative period was uneventful. Twenty-four hours later, the patient became drowsy and developed left grade 3/5 hemiparesis with low grade fever. Blood examination showed marked leucocytosis. CT scan of the head showed diffuse brain edema with no infarcts (Fig. 1e– g). In view of new focal neurological deficit after a day, vasospasm was suspected. Cerebral digital subtraction angiography (DSA) revealed diffuse vasospasm of bilateral vertebral, basilar posterior cerebral arteries and focal vasospasm of the right posterior communicating artery. Intraarterial nimodipine was infused in bilateral vertebral and internal carotid arteries that showed radiological improvement of vasospasm (Fig. 1i–l). However, there was no clinical improvement. Diagnostic lumbar puncture and cerebrospinal fluid (CSF) examination revealed cell count of 170/dl (55 % neutrophils) and normal sugar. CSF culture was sterile. His sensorium worsened over the next 2 days, alongwithworsening of hemiparesis to left hemiplegia. High grade fever had set in and leucocytosis persisted. Blood, urine and tracheal aspirate culture did not show any growth. Steroids were administered. On the fourth post-operative day, the patient became hemodynamically unstable. Haematological workup showed pancytopenia. He expired a day later. Repeat CT head showed no new findings (Fig. 1h). Unfortunately, an autopsy was not performed. Cerebral hydatidosis is often encountered in developing countries [3]. The intraparenchymal cysts are usually unilocular cysts and tend to occur in the middle cerebral artery territory. These are non-enhancing spherical cystic lesions without perilesional edema. With progressive neurological deficits and raised intracranial pressure (ICP), surgical excision remains the treatment of choice. A high index of suspicion is necessary as intraoperative cyst rupture is not desirable. The preoperative diagnosis, however, may be missed in case of multiple loculations and wall enhancement as in the index case. Besides, despite all attempts to avoid cyst Not presented at any conference.

Two Dog-Related Infections Leading to Death: Overwhelming Capnocytophaga canimorsus Sepsis in a Patient With Cystic Echinococcosis

Capnocytophaga canimorsus is a fastidious, capnophilic, fusiform, and filamentous gram-negative rod. It is part of the normal oral flora of dogs and cats and can cause an infection in humans, but is of generally low virulence in healthy individuals. A case of fatal sepsis due to Capnocytophaga canimorsus in a 46-year-old woman with clinically silent cystic echinococcosis discovered postmortem is present. She had been bitten by a dog 3 days before the symptoms appeared. The family had owned the dog for 4 years. A preliminary diagnosis of septic shock of unknown etiology with multisystem organ failure was established. Despite all the efforts, the patient died on the seventh day of hospitalization. Laboratory findings received postmortem showed Capnocytophaga canimorsus isolated from the blood culture after 7 incubation days. Autopsy showed a cyst in the liver with a fibrotic wall and necrotic eosinophilic interiors containing fragments of Echinococcus granulosus scolices. In conclusion, an interaction possibly established long ago between the host and Echinococcus granulosus conditioned immunosuppression mechanisms developed by the parasite in this case, which can explain such an aggressive course of the infection with Capnocytophaga. Two dog-related infections were fatal in the middle-aged dog owner considered healthy before this hospitalization. Vigilance concerning recent exposure to dogs or cats and potential immunosuppression risk factors must be maintained in a patient presenting with clinical features of fulminant sepsis.

Hydatid disease: a cause of renal cystic masses in children

Sirs, Primary hydatidosis of the kidney is very rare, even in endemic areas such as our country [1–4]. Diagnosis of the hydatid cyst is mainly on the basis of serologic tests and/or imaging studies [1–3]. Ultrasound and computed tomography (CT) are the important imaging modalities for hydatid disease and may clearly demonstrate the floating membranes, and typical daughter cysts in the cystic lesions [1, 2]. A 9-year-old boy was referred to our center with the chief complaint of right flank pain and weight loss. He had no history of fever. On physical examination a mildly tender bulging at the right flank area was palpated. Laboratory investigations, including those for blood sugar, blood urea nitrogen, creatinine, liver enzymes, and urinalysis, gave normal findings. Complete blood count was normal except for mild leukocytosis [white blood cells (WBCs): 12,000]. On transabdominal ultrasound, multiple anechoic cystic masses were demonstrated in the right kidney. For further delineation of the cystic masses computed tomography (CT) was performed, the scan revealing multiple cystic space-occupying lesions and excellently depicting the daughter cysts in the kidney (Fig. 1a). On the 7th day of admission, after we had obtained informed consent, the patient underwent surgical exploration under general anesthesia for confirmation of the diagnosis of hydatid disease and for the ruling out of other renal masses such as cystic renal cell carcinoma or cystic nephroma. During the operation, one of the cysts was completely removed, and the surgical specimen was diagnosed as the hydatid cyst. Owing to extensive involvement of the kidney and high risk of life-threatening rupture, complete removal of the cysts was very difficult; therefore right-sided nephrectomy was carried out. The rest of the abdomen and pelvis showed no evidence of involvement. Microscopic examination disclosed the scolices of Echinococcus granulosus, with adjacent laminated membrane, and confirmed the diagnosis (Fig. 1b). CT may be superior to ultrasonographic examination because of its capability of better evaluation of the cystic masses and for its demonstration of any enhancement in other lesions such as renal abscess, tumors, and focal pyelonephritis. In our case we observed that the CT scan could detect the daughter cysts more satisfactorily. The possibility of a striking clinical resemblance between a hydatid cyst and malignant disease of the kidney such as cystic renal cell carcinoma or cystic nephroma has been emphasized in the English literature [3–6]. We also indicate this important point in our patient. In conclusion, the most important factor in the diagnosis of hydatid disease is the high index of suspicion about its possibility. Primary hydatidosis of the kidney should always be considered in the differential diagnosis of any cystic renal mass in the pediatric groups, even in the absence of accompanying involvement of liver or other visceral organs. Pediatr Nephrol (2009) 24:1251–1252 DOI 10.1007/s00467-008-0963-2

Pulmonary hydatidosis: An unusual cause of haemoptysis

A 28-year-old female patient was referred to us with complaints of massive haemoptysis and cough with expectoration, of two years' duration. Her chest radiograph, computed tomography scan and video-bronchoscopy revealed a cystic lesion in the right upper and lower zones of the lungs. Aspiration from the cyst fluid was grossly hemorrhagic and full of inflammatory cells. On digestion of the fluid with potassium hydroxide, it showed plenty of hooklets and scolices of Echinococcus granulosus. An intact brood capsule was also seen. Diagnosis of hydatidosis was further confirmed by a positive serological and therapeutic response to albendazole.

Latex agglutination test (LAT) for antigen detection in the cystic fluid for the diagnosis of cystic echinococcosis

Latex agglutination test (LAT) was standardized and evaluated to detect hydatid antigen in fluid samples aspirated from 6 surgically proved human cases of cystic echinococcosis (CE), 4 suspected human cases of CE (2 cases of cysts in the liver which were not confirmed surgically and 2 cases of pelvic cysts later confirmed as abscesses) and 7 cases of hydatid cysts of liver in cattle. Echinococcus granulosus scolices and hook lets were seen in aspirated fluid by microscopy and the characteristic germinal layer of the cyst wall was demonstrated by histopathology in 6 human hydatid cysts operated and removed by surgery. In case of cattle hydatid liver cysts no scolices or hook lets were seen in aspirated fluid as they were sterile cysts but characteristic laminated layer of the cyst wall was demonstrated by histopathology of these cysts. The LAT could detect antigen in fluid samples collected from all 6 human cases of surgically proved CE and 7 cases of hydatid cyst liver in cattle, thus showing sensitivity of 100%. The LAT could detect antigen in fluid samples collected from 2 suspected cases of CE liver in humans, which were not operated. The LAT was found to be specific .No cross reactivity was observed .The results of the study showed that LAT could be employed as a simple and rapid diagnostic procedure, as an alternate to microscopy, to confirm the hydatid etiology of a suspected cyst.

Detection of hydatid antigen by co-agglutination in fluid samples from hydatid cysts

The co-agglutination (Co-A) procedure was standardized and evaluated to detect hydatid antigen in fluid samples aspirated from hydatid cysts. Samples were collected from 14 hydatid cysts in different organs (liver, 7; lung, 5; multiple abdominal cysts, 1; and kidney, 1) by surgery. Echinococcus granulosus scolices and booklets were seen in only 6 (42.85%) samples by routine microscopy. In contrast, hydatid antigen was demonstrated in all the samples by Co-A (100% sensitivity). Co-A could be employed as a simple and rapid diagnostic procedure, as an alternative to microscopy, to confirm the hydatid aetiology of a suspected cyst.

Influence of Ionizing Irradiation on Infectivity of Eggs of Echinococcus granulosus in Laboratory Rodents

Eggs of Echinococcus granulosus were subjected to X-irradiation at levels of 5, 10, 20, or 30 kr, and its influence on their infectivity in laboratory rodents was measured. A dose of 10 kr was sufficient to produce a significant reduction in the number of cysts developing from the embryos in each animal inoculated intraperitoneally with 15-day-old eggs. Doses of 20 and 30 kr had an inhibitory effect on both the number of animals becoming infected and the number of cysts formed. Eggs stored for 60 days were less susceptible to X-irradiation than those stored for 15 days prior to exposure. Eggs exposed to ultraviolet irradiation for 24 hr showed a marked reduction in infectivity for mice. No animals became infected after receiving 500 ultraviolet-irradiated eggs. Even in animals receiving 2,000 ultraviolet-irradiated eggs the number developing into cysts was significantly reduced compared to the controls. The findings are discussed in relation to available information on the effects of ionizing irradiation on cestode tissues and eggs. The influence of ionizing irradiation on nematodes has been studied in relation to the possible attenuation of parasites for immunization (Urquhart et al., 1962). Less attention has been given to cestodes but available evidence suggests they are highly radio-resistant. Schiller (1959) studied the effect of Xirradiation on the proglottids of Hymenolepis nana and found that eggs retained their infectivity for Tribolium confusum after doses of 15 and 20 kr. However, the resulting cysticercoids showed developmental abnormalities and were not capable of producing infections in mice. Similar results were obtained by Kuhlman (1961) who reported that eggs of Hymenolepis microstoma were able to survive doses of 10 and 15 kr. In contrast, adults of this species exposed to a series of 2.5, 5, and 7 kr showed no change in growth rate when compared to controls (Tan Bian Djoen, 1965). Dow et al. (1962) X-irradiated oncospheres of Taenia taeniaeformis with a dose of 40 kr and challenged 20 animals of which only three became infected, each having only a single cyst. Sixty kr were necessary to eliminate infectivity for mice. Movsesijan et al. (1968) demonstrated that some scolices of Echinococcus granulosus survive doses of 10, 20, 25, and 30 kr of X-rays. Development in dogs ceased or became grossly abnormal after exposure to the higher levels. The influence of ultraviolet irradiation on Received for publication 7 January 1971. cestodes has been little studied. Atmowisastro (1936) showed that only 225 ergs of ultraviolet light at 2,537 A for 15 sec reduced infectivity of eggs of Moniezia expansa by 98%. Those subjected to 510 ergs over 39 sec were no longer infective. Laws (1968) irradiated eggs of Taenia pisiformis at 3,660 A for 24 hr and demonstrated that this treatment had no effect on in vitro activation of the embryos. Prolonging exposure for a total of 8 days did not affect this result. We have been unable to find data on the se itivity of eggs of E. granulosus to ionizing radiation, although such information could have important implications both in the decontamination of infectious material or equipment and with regard to possible attenuation of oncospheres for immunization studies. The present work was carried out in an attempt to determine if exposure to measured doses of X-rays or ultraviolet light has an effect on the infectivity of eggs of E. granulosus in labora-

Study on the relation between the osmotic pressure and the evagination of Echinococcus granulosus.

In the present report the influence of the osmotic pressure on the evagination of Echinococcus granulosus scolices was studied using different concentrations of sodium chloride and sucrose solutions.

Biological Activities of Various Lipid Fractions from Echinococcus granulosus Scolices on In vitro Cultures of Hymenolepis diminuta

Thin-layer chromatography of lipid extracts of Echinococcus revealed substances with stimulatory and depressive effects on growth of excysted cysticercoids of Hymenolepis diminuta in in vitro cultures. Cholesterol depressed growth and increased mortality, unidentified steroids increased mortality and a substance with Rfs similar to farnesal stimulated growth of these forms by as much as 100%. Similar substances, untested as yet for biological activity, were found in lipid extracts of infective larvae of Trichinella spiralis and miracidia of Fasciola hepatica. The complexity of the life cycles of parasitic helminths dictates reasonably sophisticated control mechanisms. The molts of larvae and maturation to adulthood are not unlike those of insects. The bulk of literature during the last 10 years on in vitro cultivation of parasitic helminths illustrates the rather primitive state of our knowledge regarding these phenomena. A finer understanding of the involved mechanisms might well open up new avenues for control of these parasites. A chance observation that lipoidal materials were being leached from scolices of Echinococcus granulosus during preparation of ES (excretion and secretion) antigens, and the fact that scolices of this organism live in hydatid cysts in an excellent culture medium, yet do not mature, prompted these studies. MATERIALS AND METHODS The procedure followed for the collection of scolices was essentially that of Agosin et al. (1957). Livers collected from sheep and cattle at the Beirut abattoir were brought to the laboratory within 2 hr after slaughter of the host animals. The fluid was withdrawn aseptically from hydatid cysts with a syringe and needle. The settling scolices were transferred to centrifuge tubes with a Pasteur pipette, washed 3 or 4 times with distilled water Received for publication 16 February 1968. * These studies were supported in part by research grants from the Medical Research Committee, American University of Beirut and from the National Institute of Allergy and Infectious Diseases, National Institutes of Health, Public Health Service (AI-02205-08 and AI-07218-01). t Present address: Department of Biology, University of Notre Dame, Notre Dame, Indiana. + Present address: School of Pharmacy, University of Kentucky, Lexington, Kentucky. and separated by low speed centrifugation. The thoroughly washed scolices were used alive for one experiment and lyophilized to a dry powder for the remainder. Total lipids from scolices were extracted by a procedure similar to that of Folch et al. (1957). The lyophilized scolices (0.495 g) were mixed with 100 volumes (w/v) of a mixture of chloroform: methanol (2:1, v/v) and agitated on a shaker for 6 hr. The insoluble residue was then separated from the solvent by low speed centrifugation and the supernatant fluid filtered through paper. This extraction was repeated 3 more times. The combined extracts were reduced to 10 ml under reduced pressure at 40 C and were subsequently washed with an equal volume of distilled water (Beames, 1965). After standing 1 hr, the separated chloroform layer was washed with 1/2 volume of 1% KC1 solution. To the aqueous phase, an equal volume of a mixture of chloroform: methanol (2:1) was added, and in a few minutes the chloroform layer (lower phase) was easily separated. The combined chloroform extracts were kept overnight at -20 C and quickly filtered in the cold. The filtrate was dried over Na2SO4 and evaporated to dryness under reduced pressure at 40 C. The residue was weighed (0.0672 g; 13.6% of dry weight) and immediately picked up in a minimum volume of chloroform and spotted on thin layer chromatography (TLC) plates for the fractionation of its lipid content. Preliminary qualitative extractions of infective larvae of Trichinella spiralis and miracidia of Fasciola hepatica were done in a similar way. Unless otherwise specified, thin layer plates 0.25 mm thick were prepared from Silica Gel G (Merck according to Stahl). The plates were oven-dried at 110 C for 30 min and stored in a dessicator. They were reactivated at 110 C for 10 min immediately before use. Eastman Chromagrams (0.1 mm thick) were also used. Solvent development was allowed to proceed to 12 to 13 cm from the point of sample application (1.5 cm from the lower edge of the plate) in preequilibrated chambers away from light.

SCOLEX ANTIGENS IN THE LABORATORY DIAGNOSIS OF HYDATID DISEASE

An agar double-diffusion technique using an antigen made from the scolices of Echinococcus granulosus was tested as a diagnostic tool in hydatid disease and compared with similar tests using hydatid fluid as antigen. The specificity, sensitivity, and simplicity of the scolex-antigen method seems to warrant more extensive trials.

The evagination of Echinococcus granulosus scolices from lung cysts of bovine origin.

The present report deals with a study on the evagination of Echinococcus granulosus scolices from lung cysts of bovine origin, as compared to the results of an earlier one on scolices from liver cysts of equine origin. Considerably lower percentages of evagination were noted, and even the well known stimulation by a pepsin-HCl pre-treatment did not appear very effective. These slow reactions were connected with the fact that E. granulosus is obviously not fully adapted to cattle as intermediate hosts. The existence was concluded of a physiological difference between the scolices from lung cysts of bovine origin and scolices from liver cysts of equine origin, which would be related with the nature of these hosts. Finally, this difference is considered as supporting a proposed subspeciation of the European E. granulosus.

Studies on the metabolism of Echinococcus granulosus. IV. Enzymes of the pentose phosphate pathway

1. 1. Analysis of the extra-corporeal fluid of whole Echinococcus granulosus scolices at timed intervals during endogenous polysaccharide utilization showed the presence of glucose, fructose, ribulose, ribose, sedoheptulose, and glyceraldehyde. 2. 2. Evidence was obtained for the presence in cell-free extracts of glucose-6-phosphate and 6-phosphogluconic dehydrogenases, transketolase, transaldolase, phosphopentose isomerase, ribokinase, 3-phosphoglyceraldehyde dehydrogenase, triosephosphate isomerase, and possibly phosphoketopentose epimerase. No evidence for non-phosphorylative oxidation of glucose was obtained. 3. 3. The above findings indicate that the pentose phosphate pathway occurs in E. granulosus scolices, and that it is apparently operative in vivo and is thus of probably physiological importance.

Host-Parasite Relationships in Echinococcosis

Summary 1. White mice 48 days of age or younger at time of inoculation were highly susceptible to an initial infection with scolices of Echinococcus granulosus when the latter were given intraperitoneally. 2. Mice 71 days of age or older were relatively resistant to an initial infection under similar conditions. 3. Four mice which were unweaned at time of inoculation died on the 10th and 11th days postinfection. 4. The few cysts which developed in older mice were often larger than any which developed in younger counterparts. The possibility of an ecological “crowding effect” is suggested. 5. The difference in susceptibility to infection appeared to be related to the magnitude of the host's cellular response. 6. The development of hydratid cysts from scolices is described.