Abnormal Trichuris trichiura eggs detected during an epidemiological survey

Abnormal eggs of Trichuris trichiura were found in the stools of one of the patients during a study on the prevalence of intestinal parasitoses among an institutionalized population. The abnormalities observed included great variation in shape, size, and color. Similar atypical whipworm eggs have been reported in patients after treatment with mebendazole, thiabendazole, tetracloroethylene, and dithiazanine. Apparently some anthelminthics have an effect on the reproductive system of female T. trichiura, resulting in production of abnormal eggs, which could lead to misdiagnosis of the infection, since they can be mistaken as eggs of other parasites or artifacts.

Blood-feeding in the young adult filarial worms Litomosoides sigmodontis.

In this study with the filarial model Litomosoides sigmodontis, we demonstrate that the worms ingest host red blood cells at a precise moment of their life-cycle, immediately after the fourth moult. The red blood cells (RBC) were identified microscopically in live worms immobilized in PBS at 4 degrees C, and their density assessed. Two hosts were used: Mongolian gerbils, where microfilaraemia is high, and susceptible BALB/c mice with lower microfilaraemia. Gerbils were studied at 12 time-points, between day 9 post-inoculation (the worms were young 4th stage larvae) and day 330 p.i. (worms were old adults). Only the very young adult filarial worms had red blood cells in their gut. Haematophagy was observed between days 25 and 56 p.i. and peaked between day 28 and day 30 p.i. in female worms. In males, haematophagy was less frequent and intense. Similar kinetics of haematophagy were found in BALB/c mice, but frequency and intensity tended to be lower. Haematophagy seems useful to optimize adult maturation. These observations suggest that haematophagy is an important step in the life-cycle of L. sigmodontis. This hitherto undescribed phenomenon might be characteristic of other filarial species including human parasites.

Zoonotic onchocerciasis caused by a parasite from wild boar in Oita, Japan. A comprehensive analysis of morphological characteristics of the worms for its diagnosis.

Histological examination of a nodule removed from the back of the hand of a 58-year-old woman from Oita, Kyushu, Japan showed an Onchocerca female sectioned through the posterior region of the worm (ovaries identifiable) and young (thin cuticle). Six Onchocerca species are enzootic in that area: O. gutturosa and O. lienalis in cattle, O. suzukii in serows (Capricornis crispus), O. skrjabini and an Onchocerca sp. in Cervus nippon nippon, and O. dewittei japonica in wild boar (Sus scrofa leucomystax). Diagnostic characters of female Onchocerca species, such as the cuticle and its ridges, change along the body length. Tables of the histologic morphology of the mid- and posterior body-regions of the local species are presented. In addition, it was observed that transverse ridges arose and thickened during the adult stage (examination of fourth stage and juvenile females of O. volvulus). The specimen described in this report, with its prominent and widely spaced ridges, was identified as O. d. japonica. Four of the 10 zoonotic cases of onchocerciasis reported worldwide were from Oita, three of them being caused by O. d. japonica, the prevalence of which in local wild boar was 22 of 24 (92%).

Monoclonal antibody to amphomycin. A tool to study the topography of dolichol monophosphate in the membrane.

Understanding the topographical orientation of dolichol monophosphate (Dol-P) in the membrane of the endoplasmic reticulum (ER) is of utmost importance for studying the regulation of asparagine-linked protein glycosylation in eukaryotic cells. This was practically impossible due to the nonavailability of a suitable probe. Recent studies on the specific interaction between a lipopeptide, amphomycin, and Dol-P, provided an insight to develop a monospecific antibody to amphomycin which could recognize the amphomycin-Dol-P complex in order to detect Dol-P immunocytochemically in the ER membrane. We report herein the successful production of a monoclonal antibody to amphomycin. The antibody belongs to the IgG+IgM subclasses and is specific for amphomycin when analyzed by the enzyme-linked immunoassay and immunoblot procedures. The antibody recognizes with equal potency both the native amphomycin and also mild acid-hydrolyzed amphomycin from which N-terminal fatty acylated aspartic acid has been removed. Preincubation of amphomycin with the antibody partially reduced the inhibitory action of amphomycin on dolichol phosphate mannosyltransferase (EC 2.4.1.83). Furthermore, exposure of capillary endothelial cells to amphomycin, followed by the monoclonal antibody to amphomycin, followed sequentially by staining with FITC-conjugated goat anti-mouse IgG and examination under a fluorescent microscope gives intense fluorescence at the perinuclear region of the cell with a structure reminiscent of the ER.

Production of monoclonal antibodies to Sp2/O-Ag 14 myeloma cells.

The hybridoma technology developed by Kohler and Milstein allows the obtention of antibodies of a single specificity (i.e. monoclonal antibodies). This methodology was first introduced in the Immunology Laboratory of the Department of Microbiology at the Medical Sciences Campus (MSC), University of Puerto Rico (UPR) in 1986. The production of monoclonal antibodies to Sp2/O-Ag 14 reported herein describes the procedure used and is of importance because it constitutes the first work on monoclonal antibodies performed at our institution and in Puerto Rico.

Enzootic Brugia infection in a two-year-old Colombian girl.

Mature male and female filarial worms were present in a lymphatic vessel near a retro-auricular lymph node removed from a 2-year old Colombian girl. Although apparently mature microfilariae were present in the uterus of the female, none was detected in blood samples (Knott's) of peripheral blood taken during day or night. The identification of the worms as a species of Brugia is suggested by their location in a dilated lymphatic vessel, morphology of adults, and the distribution pattern of tail nuclei of the microfilariae. This case is similar to another Colombian case reported from the Departamento del Santander del Sur, and suggests that zoonotic filarial infections may not be uncommon in Colombia.

Filariasis in Colombia: prevalence of Mansonella ozzardi in the Departamento de Meta, Intendencia del Casanare, and Comisaría del Vichada.

The prevalence and distribution of filarial infections among the inhabitants of adjacent regions of the Departamento del Meta, Intendencia del Casanare, and Comisaría del Vichada in northeastern Colombia was determined by collection and examination of blood samples using the Knott's method. Mansonella ozzardi, the only species detected, was found in 2.5% of the samples collected in Meta (6/243), in 4.9% from Casanare (12/247) and in 2.5% from Vichada (3/137). All of the microfilaria carriers were Indians who had migrated from other parts of eastern Colombia, principally from the interior of Meta and Vichada. These results indicate that filariases are not endemic in the regions examined, and suggest that influx of microfilaria carriers with sufficiently high microfilaremia could establish new foci of transmission in areas where appropriate vectors are abundant.

Filariasis in Colombia: prevalence and distribution of Mansonella ozzardi and Mansonella (=Dipetalonema) perstans infections in the Comisaría del Guainía.

A survey was conducted to determine the prevalence and distribution of filarial infections among the inhabitants of Comisaría. Approximately 25% of the 604 individuals bled (Knott's sample) harbored microfilariae; more men (29.7%) were infected than women (23.7%); approximately 6% were infected with Mansonella (=Dipetalonema) perstans, 13% with Mansonella ozzardi, and 7% with both filariae. Mansonella ozzardi was more common in men than in women, and its prevalence increased with age in both sex groups; it was detected in most of the resident ethnic groups but was most common in the Puinave and the Curripaco Indians, and appeared to be distributed throughout the Comisaría. The prevalence of M. perstans was essentially the same in men as in women, and in age-groups from the 2nd to 4th decade, although its tendency to increase with age was not as marked as in M. ozzardi infections. Mansonella perstans appeared to be limited to the central and southern regions of the Comisaría, was found principally in the Curripaco Indians, and was detected in settlements situated within the drainage of both the Río Orinoco and the upper Río Negro. Approximately 9% of the white settlers (colonos) harbored M. ozzardi, and 5% M. perstans. These results indicate that both M. perstans and M. ozzardi are endemic in the Comisaría del Guainía, and suggest that the focus of M. perstans may extend further into the South American continent along the Río Negro and its tributaries.

Ultrastructure of Mansonella ozzardi microfilaria, with a comparison of the South American (simuliid-transmitted) and the Caribbean (culicoid-transmitted) forms.

Ultrastructural studies conducted to elucidate and compare the microanatomy of the South American (simuliid-transmitted) and the Caribbean (culicoid-transmitted) microfilariae of Mansonella ozzardi revealed that these microfilariae are essentially identical. The only difference detected was the larger central body of the Colombian microfilariae. Although the microanatomy of M. ozzardi microfilaria is essentially the same as that of other microfilariae, some of the subtle differences noted between M. ozzardi and other microfilariae include: amphids of unequal lengths, a large nucleus located approximately 30 microns from the anterior end, and an esophagus which appears to be less developed than that of Loa loa and Brugia spp. The microfilaria has a small cephalic hook, intracellular bacteriae in the hypodermal cells, and crystalloid inclusions which are most prominent in the R-1 cell and are also present in the hypodermal and esophageal cells. These crystalloids appear to be unique to M. ozzardi microfilariae.

Comparative morphology of Mansonella ozzardi microfilariae from Colombia and Haiti. A light microscope study.

Comparative morphological studies were conducted at the light microscope level to determine whether any difference could be detected in thin smears, thick smears, or Knott samples, between Colombian (simuliid-transmitted) and Haitian (culicoid-transmitted) Mansonella ozzardi microfilaria. Results indicated that the microfilariae from these two geographical areas are essentially identical. The small differences observed in the dimensions of microfilariae in thick and in thin smears can be attributed to different preparative procedures. The consistent morphological differences, noted in PAS-hematoxylin-stained microfilariae, from Knott smears, was that the central body was thinner and stained less intensely with the Schiff reagent in the Haitian than in the Colombian microfilariae. Although these observations suggest a physiological difference between these two forms, additional studies are needed to exclude the possibility that these differences are not indications of the age or a state of physiological activity of the microfilariae.

Attempts to establish Onchocerca volvulus infection in primates and small laboratory animals.

Attempts were made to transmit O. volvulus infection to small laboratory animals and several species of primates to identify a practical laboratory host for human onchocerciasis. Infective larvae of O. volvulus of Guatemalan origin were inoculated into the following animals: rhesus monkeys, bonnet monkeys, golden spider monkeys, black spider monkeys, galagos, opossums, jirds, newborn and adult Swiss mice, kinkajou, cebus monkey, normal and splenectomized multimammate rats, and a calf. The animals were examined for signs of developing infection for up to two years after inoculation. None of the animals tested developed a patent infection, and neither larvae nor O. volvulus adults were found during the necropsy of all the animals which died or were killed during or at the end of the examination period. It is concluded that none of the animals tested is susceptible to infection with O. volvulus.

Filariasis in Colombia: presence of Dipetalonema perstans in the Comisaría del Guainía.

Examination of 75 blood samples (Knott preparation) collected in Puerto Inrida, Coco, and Pajuil, in the Comisaría del Guainía, Colombia, disclosed 26 microfilaria carriers. Eighteen persons harbored only Mansonella ozzardi microfilariae, three were infected with M. ozzardi and Dipetalonema perstans and five harbored only D. perstans. M. ozzardi infections were found in whites, and in Indians belonging to the Curripaco, Puinave, Tukano, Guanano and Saliva tribes, but D. perstans was found only in the Curripaco Indians. Numbers of circulating microfilariae (mf) were low, 73% of the carriers had less than 200 mf/ml of blood: persons who harbored only D. perstans had less than 310 mf/ml. These results confirm the presence of D. perstans in Colombia, and suggest that its prevalence and distribution in the Comisarïa del Guainía and neighboring areas may be far greater than has been hitherto suspected.

Susceptibility of laboratory primates to infection with Mansonella ozzardi from man.

The study was undertaken to determine primates were susceptible to infection with Caribbean and/or Amazon strains of Mansonella ozzardi of man. Twenty-three animals including three chimpanzees, four squirrel monkeys, one capuchin, five rhesus and 10 patas monkeys each received, by subcutaneous or intraperitoneal injection, 25-170 infective larvae of M. ozzardi harvested either from infected Culicoides furens collected in Haiti or Simulium sp. (sanguineum complex) collected in the Colombian Amazon and transported to our laboratories in Louisiana. Patent infections were obtained in seven of 10 patas monkeys but not in any other species of primates. The prepatent period ranged in duration from 149-186 days with a mean of 168 days. All of the patas monkeys developed modest microfilaremias that persisted for as long as 1 year, the duration of our observations. Adult worms were obtained at necropsy from three of four patas monkeys. The worms were recovered from soakings of the carcass and skin rather than from the abdominal cavity and mesenteries. However, their precise habitat was not determined.

[On the Filariae of the genus Aproctella (Splendidofilariinae) (author's transl)]. / Sur les Filaires Splendidofilariinae du genre Aproctella.

Aproctella alessandroi n. sp., parasitic in various Passeriformes in Colombia and Guadeloupe, and A. golvani n. sp., a similar species with smaller microfilariae parasitic in sparrows in Guadeloupe, are described. The life cycle of A. alessandroi was studied in Aedes togoi (development in 13 days in the flight muscles; first-stage larva cylindrical; third-stage larva 1 330-1 600 microns long; oesophago-intestinal junction distinct). The larval biology of Aproctella is very similar to that of Cardiofilaria, confirming the close relationship of these two genera. The biology differs from that of two other genera of Splendidofilariinae of birds, Splendidofilaria and Chandlerella (vectors: Culicoides and Simuliids; development in flight muscles and haemocoel; first stage larva almond-shaped; third stage larva 400-600 microns de long; oesophago-intestinal junction indistinct). In these latter genera, the larval biology is remarkably similar to that of Lemdaninae of reptiles and birds (Saurositus, Eufilaria). It seems there is not a distinct separation between the Splendidofilariinae and the Lemdaninae.

Experimental congenital infection of Toxoplasma gondii in Macaca arctoides.

Congenital toxoplasmosis was studied in Macaca arctoides as a model for primates. Time-mated female monkeys were assigned to 5 experimental groups and inoculated with 4 different strains of Toxoplasma gondii before pregnancy and during various stages of gestation. All monkeys showed a rise in indirect hemagglutination antibody (IHA) titers following infection, and some had demonstrable parasitemia. Of the 23 progeny, 2 were stillbirths and 2 died soon after birth, but only the one neonate born of a mother inoculated intrauterally succumbed to acute toxoplasmosis. No physical anomalies were observed in any of the progeny. The toxoplasms organism was not isolated from any of the placentas obtained nor from the cord blood. None of the tissues from the stillborn or infant monkeys that died were positive for toxoplasmosis by mouse inoculation. The live progeny were usually born with high IHA antibody titers which were usually soon lost, indicating presence of passively acquired maternal antibody. However, 2 babies, born of mothers infected with tissue cysts on day 79 and 149 of gestation, maintained moderate to high titers for about 8 and 19 months respectively, indicating that an active infection had taken place but no clinical disease was detected. Data obtained suggest that although certain developmental stages of the toxoplasma organism and of the fetus may favor the occurrence of congenital infection, very little neonatal disease results in this primate model.

Transovarially-transmitted intracellular microorganisms in adult and larval stages of Brugia malayi.

Observation of intracellular organisms in the lateral chords of Brugia malayi adults initiated further studies to determine the prevalence of these organisms within the tissues of adult worms and of larvae. The organisms were found in the lateral chords of adult males and females, microfilariae, first-, second-, third-, and fourth-stage larvae. In the females, they were present in the oogonia, oocytes, and developing eggs, suggesting transovarial transmission within the life cycle of the filarid. The organisms may have a developmental cycle consisting of more than one stage, including a small spheroidal stage up to 0.6 micrometer in size and a larger form up to 1.5 micrometer in length, all of which occur in the cytoplasm within a vesicle formed of host membrane. Each stage lacks a definite cell wall, being bound by 2 trilaminate membranes. The bacterial entities in B. malayi resemble both in morphology and development the organisms found in other filarids, but whether they affect the vertebrate host in any way remains to be determined. Their presence within certain cells of the developing eggs could be exploited as intracellular markers for the organogenesis of the lateral chords and the ovary.

Intracytoplasmic bacteria in Onchocerca volvulus.

Ultrastructural studies on Onchocerca volvulus disclosed intracellular organisms within the lateral chords of adult worms and of the larval stages. In the females the organisms were also present in the oogonia, oocytes, developing eggs and microfilariae. The organisms, found within vesicles of host (filarid) membrane and limited to the cytoplasm of infected cells, appeared to have a developmental cycle consisting of three morphologically distinct forms: a small spheroidal form up to 0.3 micronm in size, a bacillary form up to 1.5 micron7 in length and 0.7 micronm in diameter, and a third form, intermediate in size between the former and the latter, characterized by a dense inclusion. The intravesicular location and the developmental cycle consisting of three distinct forms are the two characteristics which suggest that these organisms are more similar to the chlamydiae than to the rickettsiae, in spite of their being transovarially transmitted. The significance of these findings with respect to the host-parasite relationship and pathogenesis of onchocerciasis is presently unknown and will require further study.