First report of a member of the family Mermithidae parasitizing the sandhopper Orchestoidea tuberculata (Amphipoda, Talitridae) in Chile

Specimens of the sandhopper Orchestoidea tuberculata (Amphipoda; Talitridae) collected from sandy beaches in south-central Chile, were found to be parasitized by juvenile mermithids, constituting the first record of a mermithid infecting a marine amphipod in Chile. A morphological description of juveniles is provided. Sequence analyses based on mitochondrial COI and nuclear 18S rDNA of the mermithids showed extremely low genetic variation. Phylogenetic analyses indicate that the mermithid is more closely related to Hexamermis agrotis, which parasitize Coleoptera, than to Thaumamermis zealandica, which parasitizes New Zealand confamilial talitrid amphipods.

Review of the concept of Profilicollis Meyer, 1931 with a description of Profilicollis rancoensis n. sp. (Acanthocephala: Polymorphidae) from the freshwater crab, Aegla abtao Schmitt, 1942 (Decapoda: Anomura) in Chile, with a key to congeneric species

Profilicollis rancoensis n. sp. is the tenth species of Profilicollis Meyer, 1931 which includes 9 other species mostly known from marine decapod crabs and shore birds. Cystacanths of P. rancoensis are described from the dominant freshwater crab Aegla abtao in Ranco Lake, Chile and are morphologically distinguished from cystacanths of the 9 other species based on a combination of 4 characters. These are body size, number of proboscis hook rows, number of hooks per row, and length of the largest anterior 2-4 hooks. Male and female cystacanths of P. rancoensis are 2.10-3.33 mm long having an ovoid proboscis with 14 rows of 6-7 hooks per row, with the largest anterior 2-4 hooks being 105-110 micrometers long; the anterior trunk has many small spines in 70-80 concentric rings, each with 50-60 spines around them; hook roots are simple, directed posteriorly, about as long as the blades anteriorly with unremarkable anterior manubria; the cephalic ganglion are in mid-receptacle just anterior to the level of the anterior trunk; the lemnisci are long and slender; the testes are in the anterior trunk, posterior trunk, or one in each; the primordia of 2 tubular cement glands are evident; strong bundles of fibers link the anterior and posterior trunk; and the posterior trunk has a corrugated surface cuticula. Molecular analysis (COI and 18S) sequences coincided with the morphology and support its taxonomy. The phylogenetic profile revealed that P. rancoensis n. sp. fell into the Profilicollis clade. Both sequences showed low genetic variation, and three different haplotypes were found. The new species was more closely related to P. botulus (Van Cleave, 1916) Witenberg, 1932 than to other Profilicollis species.

New perspectives on morphological and genetic variability of Corynosoma bullosum [Linstow, 1892] parasitizing southern elephant seals from the Antarctic Peninsula

Previous descriptions of Corynosoma bullosum (Linstow, 1892) show that specimens vary greatly in the proportions of different body structures, measurements of females and males, number of rows of hooks, and egg measurements, among other features. We redescribe this species from specimens found in southern elephant seal faeces from King George Island. We also provide a molecular characterization, in addition to 5.8S and internal transcribed spacer (ITS) existing sequences. We examined 41 elephant seals, and 30 adult acanthocephalans were found in 15 of them. The specimens were identified as belonging to the genus Corynosoma due to each having a tubular body with an inflated anterior part forming a thorny disk and the posterior part bearing somatic spines on the ventral surface, and genital spines surrounding the genital pore. Individual morphology corresponded to C. bullosum: large size, marked sexual dimorphism, and proboscis with 16-18 rows of spines with 11-15 spines per row. The molecular profile of three specimens of C. bullosum was analysed using 18S rDNA. We inferred phylogenetic relationships of the family Polymorphidae using maximum likelihood and Bayesian inference. We provide an updated morphological redescription for C. bullosum including electron microscopy photographs and molecular data. The 18S gene sequences showed low genetic variation and supported that C. bullosum is a sister to Corynosoma australe.

Phylogeny and Life Cycles of the Archiacanthocephala with a Note on the Validity of Mediorhynchus gallinarum

PURPOSE

The molecular profile of specimens of Mediorhynchus gallinarum (Bhalero, 1937) collected from chickens, Gallus gallus L. in Indonesia was analysed. The aim of this study was to assess the phylogenetic position of species of Mediorhynchus within the order Giganthorhynchida.

METHODS

We used one mitochondrial gene (cytochrome oxidase 1) and one nuclear gene (18S ribosomal RNA) to infer phylogenetic relationships of class Archiacanthocephala.

RESULTS

The COI and 18S rDNA genes sequences showed that M. gallinarum had low genetic variation and that this species is sister to Mediorhynchus africanus Amin, Evans, Heckmann, El-Naggar, 2013. The phylogenetic relationships of the Class Archiacanthocephala showed that it is not resolved but, however, were mostly congruent using both genes. A review of host-parasite life cycles and geographic distributions of Archiacanthocephala indicates that mainly small mammals and birds are definitive hosts, while termites, cockroaches, and millipedes are intermediate hosts.

CONCLUSIONS

While the intermediate hosts have wide geographic distributions, the narrow distribution of the definitive hosts limit the access of archiacanthocephalans to a wider range of prospective hosts. Additional analyses, to increase taxonomic and character sampling will improve the development of a robust phylogeny and provide more stable classification. The results presented here contribute to better understanding of the ecological and evolutionary relationships that allow the host-parasite co-existence within the class Archiacanthocephala.

A comparative assessment of the morphology of Profilicollis altmani (Acanthocephala, Polymorphidae) from crustaceans and shore birds in Peru, with special notes on hook elemental analysis (EDXA), SEM imaging, histopathology, and molecular profile

The morphology of cystacanths and adults of Profilicollis altmani (Perry, 1942) Van Cleave, 1947 (Polymorphidae) were studied from the Pacific mole crab Emerita analoga (Stimpson) (Crustacea, Hippidae) and Belcher's gull Larus belcheri (Vigors) (Aves, Laridae), respectively, in Peru. Comparative morphometrics with accounts of other populations of P. altmani from elsewhere off the Pacific and Atlantic coasts of North and South America revealed marked intraspecific population variations. We report scanning electron micrographs (SEM) of new features, not before noted or captured in line drawings by earlier observers. We further present microscope images that reveal internal details not previously reported or possible to see with SEM. Energy dispersive X-ray analysis (EDXA) revealed unusual patterns in the chemistry of proboscis hooks especially the high sulfur and diminished phosphorous and calcium in hook tips and low sulfur and high levels of phosphorous and calcium at mid hooks. The size and shape of all hooks of the cystacanths are reported for the first time. Histopathological studies in L. belcheri from Peru are also included. Cystacanths of P. altmani from California were also analyzed for molecular patterns and compared with other sequences reported from other locations. The molecular data and the analysis of our new sequences of cytochrome oxidase I (COI) showed that haplotypes of P. altmani had low genetic variation; the species is not geographically structured, and within its clade no monophyletic group is formed.

GEOGRAPHICAL VARIATION OF ENTEROPARASITISM IN THE SOUTHERN SEA LION OTARIA FLAVESCENS (SHAW, 1800) OFF THE COAST OF CHILE AS EVIDENCED WITH COPROLOGICAL TESTS: IMPLICATONS FOR ZOONOTIC RISKS

The scarce information on the helminth fauna in otariids from the Southeastern Pacific comes mainly from stranded individuals or killed for that purpose. In this study, we compared the abundance and composition of enteroparasitic assemblages of Otaria flavescens using coprological techniques. Three sampling localities from north to south spanning 2,200 km off the Chilean coast were considered (Iquique, Viña del Mar, and Talcahuano). In all, 60 fecal samples were collected, and eggs belonging to 5 taxa were found in 91.6% of the samples. They were the anisakid nematodes Contracaecum and Pseudoterranova, the cestode Adenocephalus (syn. Diphyllobothrium), the trematode Ogmogaster, and the acanthocephalan Corynosoma. Samples from southern Chile (Talcahuano) showed the highest prevalence. Adenocephalus eggs had the highest prevalence and abundance in Iquique and Talcahuano, whereas Ogmogaster was the less prevalent and abundant in all sampling localities. Corynosoma eggs had similar prevalence and abundance among sampling localities, and Pseudoterranova eggs were absent in Iquique and with median prevalence values in Viña del Mar and Talcahuano. Thus, the composition of parasite egg assemblages was different between sampling localities. These differences between sampling localities may help to explain differential records of some zoonotic parasitoses such as pseudoterranovosis and diphyllobothriosis in Peru and Chile, where consumption of raw or marinated fish (ceviche) is common. For example, the lower diversity of parasite egg assemblages in the northern Chilean coast may be due to the absence or lower abundance of first intermediate/paratenic hosts of Pseudoterranova.

Morphological updates and molecular description of Heterosentis holospinus Amin, Heckmann, & Ha, 2011 (Acanthocephala, Arhythmacanthidae) in the Pacific Ocean off Vietnam

Heterosentis holospinus Amin, Heckmann & Ha, 2011 (Arhythmacanthidae) was first described from the striped eel catfish, Plotosus lineatus (Plotosidae) in Halong Bay, Vietnam. New morphological information, scanning electron microscope images, molecular analysis, and Energy Dispersive X-ray analysis (EDXA) of hooks of specimens of H. holospinus from a new collection from the common ponyfish, Leiognathus equulus (Leiognathidae), in Quang Binh, Gulf of Tonkin, Vietnam are reported here for the first time. Additional details of the anterior trunk cone, proboscis hooks, wholly spined trunk, duck-bill-like spines with micropores, and micropore distribution, are described. The unique metal composition of hooks (EDXA) demonstrated a considerably higher level of calcium and phosphorus but lower level of sulfur at the hook basal arch than at the hook tip and edge. An analysis of our new sequences of cytochrome oxidase 1 (COI) showed that H. holospinus had low genetic variation and two haplotypes.

Widespread infection of Areospora rohanae in southern king crab (Lithodes santolla) populations across south Chilean Patagonia

Cottage cheese disease is caused by microsporidian parasites that infect a wide range of animal populations. Despite its potential to affect economically important activities, the spatial patterns of prevalence of this disease are still not well understood. Here, we analyse the occurrence of the microsporidian Areospora rohanae in populations of the king crab Lithodes santolla over ca 800 km of the southeastern Pacific shore. In winter 2011, conical pots were deployed between 50 and 200 m depth to capture crabs of a wide range of sizes. The infection was widely distributed along the region, with a mean prevalence of 16%, and no significant association between prevalence and geographical location was detected. Males, females and ovigerous females showed similar prevalence values of 16.5 (13-18.9), 15 (9.2-15) and 16.7% (10-19%), respectively. These patterns of prevalence were consistent across crab body sizes, despite the ontogenetic and sex-dependent variations in feeding behaviour and bathymetric migrations previously reported for king crabs. This study provided the first report of the geographical distribution of A. rohanae infecting southern king crabs.

Mesoscale spatiotemporal variability in a complex host-parasite system influenced by intermediate host body size

BACKGROUND

Parasites are essential components of natural communities, but the factors that generate skewed distributions of parasite occurrences and abundances across host populations are not well understood.

METHODS

Here, we analyse at a seascape scale the spatiotemporal relationships of parasite exposure and host body-size with the proportion of infected hosts (i.e., prevalence) and aggregation of parasite burden across ca. 150 km of the coast and over 22 months. We predicted that the effects of parasite exposure on prevalence and aggregation are dependent on host body-sizes. We used an indirect host-parasite interaction in which migratory seagulls, sandy-shore molecrabs, and an acanthocephalan worm constitute the definitive hosts, intermediate hosts, and endoparasite, respectively. In such complex systems, increments in the abundance of definitive hosts imply increments in intermediate hosts' exposure to the parasite's dispersive stages.

RESULTS

Linear mixed-effects models showed a significant, albeit highly variable, positive relationship between seagull density and prevalence. This relationship was stronger for small (cephalothorax length >15 mm) than large molecrabs (<15 mm). Independently of seagull density, large molecrabs carried significantly more parasites than small molecrabs. The analysis of the variance-to-mean ratio of per capita parasite burden showed no relationship between seagull density and mean parasite aggregation across host populations. However, the amount of unexplained variability in aggregation was strikingly higher in larger than smaller intermediate hosts. This unexplained variability was driven by a decrease in the mean-variance scaling in heavily infected large molecrabs.

CONCLUSIONS

These results show complex interdependencies between extrinsic and intrinsic population attributes on the structure of host-parasite interactions. We suggest that parasite accumulation-a characteristic of indirect host-parasite interactions-and subsequent increasing mortality rates over ontogeny underpin size-dependent host-parasite dynamics.

Isolation of shiga toxin-producing Escherichia coli from a South American camelid (Lama guanicoe) with diarrhea

Shiga toxin-producing Escherichia coli belonging to serotype O26:H11 was isolated from a 2-month-old guanaco with severe watery diarrhea. E. coli colonies carried the stx1 and eae genes, showed localized adherence to HEp-2 cells, and produced enterohemolysin. A serological response to lipopolysaccharide O26 was observed at the onset of diarrhea.

Non-O157 Shiga toxin-producing Escherichia coli isolated from diarrhoeic calves in Argentina

Faecal samples from 76 diarrhoeic calves belonging to 36 farms located in the Pampas plain, Argentina, were examined for Shiga toxin-producing Escherichia coli (STEC). A total of 15 STEC strains were isolated from 12 (15.8%) calves which came from six different farms. All stx positive strains assayed by PCR were also positives in the Vero cell cytotoxicity test. The majority (60.0%) of the STEC strains carried the stx(1) gene. Twelve (80.0%) of the STEC isolates which belonged to serotypes O5:H- (n = 4), O26:H11 (n = 4), O26:H- (n = 1), O111:H- (n = 2), and O123:H38 (n = 1) were also enterohaemolysin (EHly) positive and carried the gene encoding for intimin (eae). All the stx positive strains were negative for the bfpA gene. Localized adherence to HEp-2 cells were observed in 83.3% of the eae+ STEC strains. STEC belonging to serotype O5:H- showed atypical biochemical properties, including urease production. Urease was also produced by two strains belonging to serotypes O153:H? and non-typeable, respectively. Resistance to three or more antibiotics was observed in 12 (80.0%) of the STEC isolates. Most of the serotypes of STEC recovered in this survey carried virulence traits that are associated with increased human and bovine pathogenicity. The present study shows that highly virulent STEC strains are being shed by diarrhoeic calves from farms located in a high incidence area of human STEC infections.

Serine proteinases with gelatinolytic activity in an Aspergillus fumigatus allergenic extract

The presence of proteolytic activity in Aspergillus fumigatus (Af) extract was analyzed in polyacrylamide gelatine containing gels at different pHs. The gelatinolytic pattern showed three major activities (180, 70, and 34 kDa bands) over a broad pH range (pH 4-8). All bands showed maximum activity at pH 8, and the activity declined at lower pH, showing no activity at pH 2. The susceptibility of the proteolytic activity to protease inhibitors confirmed that the fungal extract contained serine proteinases, and one of them, the 34 kDa band, showed a chymotrypsin-like proteinase. The immunochemical fungal extract properties were studied by western blot, and the samples were run in the presence or absence of denaturing and reducing (DTT) conditions. Two protein bands located at approximately 180 and 84 kDa showed immunoreactivity with allergenic patients' anti-Af serum, when the samples were run under denaturing and reducing conditions. In the native form an additional third immunoreactive band of about 70 kDa was found. There were no immunoreactive bands toward IgE about 34 kDa. Periodate treatment caused the decrease or disappearance of the immunoreactivity in the bands, demonstrating that epitopes recognized by serum IgE specific to Af are partially composed by carbohydrates (180 and 70 kDa bands) while others (84 kDa) are carbohydrates. Although further investigations are needed, these preliminary results suggest alkaline serine proteinases from Aspergillus fumigatus as one of the factors responsible for the fungal allergenicity.

Occurrence and characteristics of CS31A antigen-producing Escherichia coli in calves with diarrhoea and septicaemia in Argentina

CS31A is a K88-related non-fimbrial adhesin first described on Escherichia coli strains isolated from diarrhoeic and septicaemic calves. In this report, CS31A antigen was screened by immunological methods and confirmed by PCR among bovine E. coli isolates. In addition, CS31A-producing strains were characterized with respect to different fimbrial antigens, O-serogroup and other properties related to virulence. Faecal or tissue specimens of 100 diarrhoeic or septicaemic calves and 27 older cattle with different pathologies from 71 outbreaks or individual cases that occurred in Buenos Aires province, Argentina, were examined. CS31A + E. coli strains were isolated from 21 (21.0%) calves from 16 outbreaks or individual cases. No CS31A + E. coli was detected in samples from cattle more than 1 year old. Fimbriae F5, F41, F17a and F17b were not detected among the CS31A-producing strains. Three (14.3%) of the CS31A+ E. coli strains expressed the F17c fimbria. All of the 21 isolates exhibited at least one property of septicaemic strains (resistance to serum, production of aerobactin or colicins) but none of them demonstrated heat-stable enterotoxigenic activity. CS31A + E. coli isolates belonged to 10 serogroups, more commonly O8, O7, O17 and O21. The results obtained here confirm the worldwide distribution of CS31A antigen in bovine E. coli strains. However, CS31A + or CS31A + /F17c + E. coli were less frequently isolated than they were in North hemisphere countries.

Proteinase and gelatinolytic activities of house dust mite and cockroach extracts

The presence of gelatinolytic activity in dust mite and Periplaneta americana allergenic crude extracts were studied. The former presented major activity in a broad band between 45 and 66 kDa and minor activity at 32 kDa, while the latter showed a more complex pattern with gelatinolytic activity at 90, 78, 65, 34, 32 and 24 kDa. When the proteolytic activity patterns of dust mites and cockroach crude extracts were analyzed at three different pH levels, the proteases in both cases were optimally active at pH 6, showed no activity at pH 3.5 and little activity at pH 8.5. The susceptibility of both extracts to a set of well-known protease inhibitors suggested that they are composed of cysteine and serine proteinases, the latter probably being a trypsin-like type. When immunochemical properties were studied, dust mite bands of about 200, 110, 65, 60 and 43 kDa showed immunoreactivity against a polyclonal human anti-dust mite serum, with the band of approximately 200 kDa presenting the highest antigenicity. A similar analysis was applied to the cockroach extract, which exhibited immunoreactive bands at 90, 78, 65 and 34 kDa when incubated with a polyclonal rabbit anti-Blatta serum. Only those of 90, 78 and 65 kDa reacted against a polyclonal human anti-Blatta serum. These results suggested a correlation between some proteases with gelatinolytic activity and the allergenicity of both extracts.

Bat feces as an indoor allergen

We have demonstrated in an animal model (specific IgG) as well as in atopic patients suffering from rhinitis/asthma (specific IgE) that bat feces have antigenic properties. A single peak with high glycoprotein content was obtained by chromatography, while SDS-PAGE revealed several proteins between 29 and 116 kDa which showed immune serum blotting at 43.6 and 66 kDa. Positive specific skin tests with bat feces and IgE-RAST anti-bat feces were detected in atopic patients living in tall buildings and old houses in Buenos Aires. As bat feces did not cross-react with bat epithelium, studies evaluating rat serum and epithelium and pigeon feces in order to analyze the role of bat serum proteins, such as IgA, are encouraged.

Hypersensitivity pneumonitis induced by Penicillium notatum antigens in guinea pigs

Data concerning the experimental induction of hypersensitivity pneumonitis in guinea pigs using a glycoprotein derived from Penicillium notatum are presented. This antigen was obtained from the mycelial and metabolic products of the cultures passed through a Sephadex G-50 column. It was aerosolized for inhalation by adult guinea pigs for 12 weeks to detect specific serum IgM, IgG and IgE antibodies as well as sensitized leukotriene CD4 cells. Histopathological studies of the lungs showed interstitial infiltrates of macrophages and leukotriene cells, cellular bronchiolitis and single non-necrotizing granulomas. The results from this animal model suggest that this hypersensitivity pneumonitis is a typical delayed-type reaction due to chronic contact with the heterologous glycoprotein of Penicillium.

Interstitial pneumonitis induced in guinea pigs by the antigens of Rhizopus nigricans

Rhizopus nigricans (Rn) is one of the most common members of the Mucorales that produces opportunistic infections and hypersensitivity states. Data concerning experimental induction in guinea pigs of hypersensitivity pneumonitis with a glycoprotein antigen are presented. This antigen was obtained from the mycelial and metabolic products of the cultures and was aerosolized during 12 weeks. The presence of specific antibodies (IgG and/or IgE) was detected by serological techniques; histopathological studies of the lungs showed interstitial infiltrates of macrophages and LTCD8+ cells, as revealed by the MoAb used. Single non-necrotizing granulomas were characteristic from the tenth week to the end of the experiment. The results from this animal model suggest that hypersensitivity pneumonitis is a typical delayed-type reaction due to chronic contact with the heterologous glycoprotein of Rn. The relation of Rn antigen and the development of occupational diseases of the lung such as malt-worker's lung and wood-trimmer's disease is proposed and discussed.

Cross reactivity between the antigens of Periplaneta americana and Triatoma infestans

The cockroach Periplaneta americana (Pa) and the reduviid Triatoma infestans (Ti) are two very common insects in Argentina that pollute indoor and outdoor environments. They are also strongly immunogenic in animals and in atopic men. Several immunological methods such as serological absorption procedures, diffusion gel methods and capillary electrophoresis were applied in order to establish the existence of common glycoprotein epitopes in the cockroach and in the reduviid. The presence of specific antibodies (IgG & IgE) were detected in rabbits as well as in human sera. The RAST and RAST-inhibition confirmed the cross-reactivity between these two antigens. Capillary electrophoresis evoked similar patterns among Pa, Ti and the moults of the nymphs of Ti. All these findings have clinical and epidemiological importance.

IgE antibodies against snake venoms

A similar event was detected in the clinical records of a small group of atopic patients living in the northern provinces of Argentina, i.e., they were bitten by a snake of the Bothrops species (or yarará) during their rural activities (woodcutters, cattle-drivers and farmers). Those who were bitten twice suffered an acute episode of hives and angioedema within 15 minutes after the snake bite. The presence of specific antibodies against Bothrops alternata (Ba) extract was detected by means of RAST for IgE and Ouchterlony and Boyden for IgG. The Ouchterlony also demonstrated crossreactivity among the venoms of the Bothrops species and the positivity of the six fractions obtained by DEAE-cellulose column fractionation against the horse anti-Ba serum. The Ba antigen induced a definite inhibition of the RAST. We presume that hives and angioedema in atopic patients immediately after a second snake bite could be attributed to the presence of a specific IgE antibody against the venom, and must not be misinterpreted with the toxic effects that appear later.

Interstitial pneumonitis induced in guinea pigs by Triatoma infestans antigens

Data concerning the experimental induction of hypersensitivity pneumonitis in guinea pigs with a Triatoma infestans antigen are presented. Glycoproteins obtained from the chitinous structures of T. infestans (79 kd + 11 kd) were aerosolized daily to guinea pigs during 7 weeks. The presence of specific antibodies (IgG and IgE) was detected by serological techniques; histopathological studies of the lungs showed interstitial infiltrates of macrophages and T-cells. Single non-necrotizing granulomas were seen at the seventh week of the experiment. The results from this animal model suggest that this hypersensitivity pneumonitis is a typical delayed-type reaction due to chronic contact with the heterologous glycoproteins of T. infestans.

A citrus fruit-exclusion diet in sensitive patients and its influence on specific antibodies

The presence and kinetics of specific IgE and IgG antibodies against the oranges Citrus aurantium sinensis (CAS) and Citrus silension (CS) were studied in 41 atopic and 20 non-atopic children aged 8-12 years. Diagnostic procedures such as intracutaneous skin tests, IgE PRIST and anti-CAS and anti-CS IgE and IgG RAST were performed in both groups. A citrus fruit-exclusion diet was maintained for 180 days. The comparison of the results before and after the diet showed no significant changes in skin reactivity and RAST values, and even a slight increase was recorded in the latter. We have attempted to explain these puzzling findings.

Immunochemical properties of the antigens of Triatoma infestans

Taxonomically related to the cockroach Periplaneta americana (Pa), Triatoma infestans (Ti) is an insect that parasitizes two-thirds of Argentina and acts as a vector for American trypanosomiasis. The glycoproteins obtained by a Sephadex G-150 column fractionation from the whole-body extract prepared with the chitinous structures revealed antigenicity in rabbits, which developed specific IgG after 8 weeks of immunization, as detected by several serological techniques. Atopic patients living in the northern provinces of Argentina--Santiago del Estero and Chaco (endemic area for Ti)--with rhinitis/asthma showed immediate positive skin tests to Ti and its fractions, as well as an IgE-RAST-anti-Ti in 30-36% of them. Healthy nonatopic adults of the same area and other atopics and nonatopics from Buenos Aires (non-endemic area) were selected as controls and showed negative type I skin tests, as well as specific RAST. The existence of common epitopes between Ti and Pa was confirmed by absorption techniques, RAST inhibition, IEF and STIF-RAST. These findings have clinical and epidemiological connotations.

IgE antibodies against Neisseria flavescens

Bacterial allergy is still a matter of controversy. We sustain that this name should be employed only in the presence of a specific IgE against antigens from bacteria. In 100 atopic patients and 100 healthy controls with Neisseria flavescens in their pharyngeal exudates, we performed type I immediate skin tests with Neisseria flavescens and IgE-RAST throughout 1 year. Positive wheal and flare reactions were elicited in 8 of 100 atopic patients as well as in 3 of 100 nonatopic subjects. IgE-RAST/anti-Neisseria flavescens was found in 6 of the former group and in 1 of the latter. Neither late-phase nor Arthus-like reactions were recorded. Neisseria flavescens is a non-pathogenic commensal of the oropharynx with scarce antigenic properties and seems not to play an important role in these conditions (rhinitis/asthma). Bacterial immunotherapy should be considered only in the presence of specific IgE antibodies with careful selection of the bacteria or their antigens.

Antigenicity of Penicillium notatum in animals and in atopic patients

A mycelial and metabolic extract of Penicillium notatum (PN) was passed through Sephadex G-50 and DEAE-cellulose columns in order to separate soluble fractions that revealed a complex composition. Their proteins and hexoses were recorded with a LKB Uvicord spectrophotometer and quantified by the Lowry and the indol techniques. On the other hand an animal model was developed in rabbits and an IgG precipitin and hemagglutinating antibodies were obtained. The PN extract as well as those fractions with the higher protein content appeared positive when they were checked against the antiserum by means of Ouchterlony, Boyden and immunoelectrophoresis. The molecular weight of PN was established in 52,000 daltons approximately in comparison with well known marker proteins. Adult human beings suffering perennial rhinitis and bronchial asthma showed positive type I skin tests with PN and its most conspicuous fractions (glycoproteins). A RAST-IgE-anti-PN was prepared following Ceska's procedure and challenged against all human sera. Only 40% of the patients revealed a positive RAST IgE-anti-PN which correlated significatively with the protein fractions (35%) and with the skin tests (43% and 39%, respectively). These results reinforced the idea that PN is a potent antigenic mold both in animals and in humans in whom we detected an IgE specific antibody presumably related to their atopic clinical condition.

Induction of anti-orange antibodies in rabbits

The capacity of certain foods to cause allergic reactions is well known. The four types of mechanisms that Gell and Coombs described in 1968, are involved in these reactions, although the reaginic antibodies retain the paramount attention of the immunologists. The physiochemical composition of the allergen molecule is the goal of investigators with the purpose to clarify the intrinsic kinetics of antibody synthesis. This paper contributes to the conflicting data about orange allergens especially those obtained from Citrus Aurantium Sinensis and Citrus Silension (CAS and CS, respectively). Glycoproteins were separated by gel filtration through a Sephadex G-50 column. A definite protein peak was obtained meanwhile several hexoses appeared throughout the fractionation procedure. These molecules have adequate physiochemical properties that make them able to trigger the immunological response (molecular weight, definite chemical composition and glycoprotein content). Although CAS and CS have a similar chemical composition a slight inverse proportion of proteins and hexoses was demonstrated between the two classes. Molecular weights were different for CAS (51.500) and for CS (37.000) in comparison with well established protein makers. Ouchterlony revealed two precipitin lines in the CAS-anti-CAS system but none in the CS-anti-CS one. The Boyden technique showed a titre of 1/256 in the first case and only of 1/64 in the second of specific anti-orange antibodies. All the eluted fractions gave negative results although they were concentrated ten times by pre-evaporation. This animal model reinforced the statement that after a long and continuous exposure to orange antigens it was possible to develop specific antibodies. It is assumed that this phenomenon happens in atopic children with it's diagnostic and therapeutic importance.

Immunological findings in human beings with autoimmune uveitis

Thirty-four adult patients suffering from uveitis of unknown origin were submitted to an immunological protocol where specific and non-specific parameters were checked. Serum IgA, IgG and IgM appeared within normal values meanwhile IgE-PRIST was undoubtedly increased in 27 out of 34 patients. The presence of autoantibodies such as antimitochondrial and antismooth muscle were detected in a few patients with Harada's syndrome; high serum levels of immune complexes were also detected in this little group of patients with posterior uveitis. Serum complement fractions showed no significant changes. Antirretinal IgG antibodies were present in almost 40% of the patients especially in those who also have autoantibodies and immunocomplexes. The histoimmunofluorescent technique revealed positive images at the retinal membrane agreeing with the histopathological lesions obtained in the experimental model. The positive cross reactivity between bovine tissue sections and the sera from patients with uveitis reinforced the idea of the presence of common epitopes in the S-antigen of both origins. LT-CD4 and LT-CD8 serum lymphocytes showed contradictory results though both subpopulations appeared diminished. The ratio between them kept within the normal range or slightly increased (2.3-2.8). Sensitized lymphocytes to the S-antigen were detected by the MIF technique in one-third of the patients. The presence of IgG antiretinal antibodies led us to speculate about the possibility that an ADCC mechanism could also participate in the etiopathogenesis of the autoimmune uveitis. On the other hand the presence of a specific antiretinal IgE antibody must play a paramount role in increasing the vascular permeability and thus enhancing the humoral and cellular events in the inflammatory focus.(ABSTRACT TRUNCATED AT 250 WORDS)

Immunochemical properties of the antigens involved in the pigeon breeder's disease

The pigeon breeder's disease is a form of extrinsic allergic alveolitis caused by the exposure to pigeon droppings. Chemical analysis of this antigen was carried out employing column fractionation techniques. Sephadex G-50 and DEAE cellulose were performed and several proteins and hexoses peaks were recorded. Molecular weights were determined by comparison with standardized marker proteins passed through a drop counting fraction collector. The whole extract revealed a molecular weight of 100 Kd while fraction 1 showed 66 Kd and fraction 2 only 30 Kd. A guinea pig experimental model was developed with the whole extract injected by the intradermal route, administered by an intragastric catheter or aerosolized in a glass chamber. Histopathological studies were carried out with the lungs, kidneys, liver and spleen obtained by the necropsy of the animals. The lungs and the kidneys showed the paramount changes in their structures with lymphomononuclear infiltrates and an Arthus-like phenomenon surrounding the vessels. Immunological techniques were applied to the sera and the lymphocytes obtained from the animals. Precipitin and hemagglutinating IgG antibodies were detected against the whole extract and the fractions obtained by column fractionation. Sensitized lymphocytes were also detected. This experimental model represents a guide in the approach to the human allergic alveolitis whose immunological findings will be presented in a forth-coming report.

Immunochemical properties of the antigens of Blattaria sudamericana

An extract of the cockroach Blattaria sudamericana (BS), a very common insect in Argentina, was passed through Sephadex G-200 and DEAE cellulose ion exchange columns. This method yielded 2 proteins and 6 hexoses whose quantities were determined by absorbance in a LKB Uvicord spectrophotometer at 280 nm and 470 nm respectively. Protein contents were also recorded by the Lowry method and the micro-Kjehldal technique. Adult albino rabbits were immunized with a mixture of BS and complete Freund's adjuvant over a period of thirteen weeks. The antisera obtained were studied by the Ouchterlony method, the immunoelectrophoresis and the passive hemagglutination technique against BS and the eluated fractions with the highest protein content. Molecular weights were studied with the usual marker proteins subjected to gel filtration by a Sephadex G-200 column. Each protein concentration was 13.5 mg/ml in a volume of 1.5 ml meanwhile BS was 42 mg/ml. This antigen showed a molecular weight of 180,000 daltons. Fifty untreated atopic patients of both sexes with ages between 19 and 74 years suffering perennial rhinitis and bronchial asthma were chosen according to the American Thoracic Society criteria. Their IgE levels ranged between 110 and 3000 KU/L with an average of 620 KU/L. IgE anti-BS-RAST showed positive results in half of the patients while type I positive skin tests with BS 1:100 appeared in 62% of the atopic group.

Isolation and characterization of soluble fractions of Dermatophagoides farinae

Dermatophagoides farinae extract was filtered through Sephadex G-50 and DEAE-cellulose columns to study its chemical composition. Fractionation on Sephadex G-50 resulted in one definite peak of protein and in three sugar peaks. Fractionation of the protein peak on DEAE-cellulose produced four more protein peaks and another five sugar peaks. Twenty-one untreated allergic patients suffering from perennial rhinitis and bronchial asthma with clinical sensitivity to house dust were subjected to skin tests with house dust 1:100, dermatophagoides farinae 1:100 and also its thirteen eluted fractions 1:100. Positive results were recorded with house-dust, mite and six or perhaps seven fractions consisting of three or four proteins and three sugars. Immunization in rabbits with mite extract revealed only one slight precipitin band by the Ouchterlony technique and a 1:20 titer of hemagglutinating antibodies. The antigen or antigens of mite extract seemed to be producers of type I reactions rather than circulating antibodies of the IgG class. This represented a point of controversy for the therapeutic application of Dermatophagoides farinae in human desensitization.