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.

I've got you under my skin: inflammatory response to elephant seal's lice.

Seals (Phocidae) undergo an annual cycle of moulting that implies hair regeneration, and in the case of southern elephant seals, it also involves the superficial strata of the epidermis. Therefore, surviving the moulting period is crucial for their obligate and permanent ectoparasites. Throughout evolutionary time, sucking lice (Echinophtiriidae) have developed morphological, behavioural and ecological adaptations to cope with the amphibious lifestyle of their hosts. Lepidophthirus macrorhini, the Southern elephant seal louse species, faces the additional challenge of surviving attached to the host during the moulting period. Since lice live on the skin, L. macrorhini has developed a unique survival strategy by piercing the skin of their host, thus keeping them protected from moulting. During fieldwork in Patagonia and Antarctica, skin samples with lice within were collected for histological analysis to assess whether these parasites caused damage to the host. Lice generate an inflammatory process in the host's dermis, and these lesions could alter the normal chemical and mechanical protective properties of the skin facilitating secondary infections. Further studies that analyse the potential pathogens in those skin lesions are necessary to properly assess the real impact of ectoparasites on their host health.

So happy together: juvenile crabeater seal behavior improves lice transmission.

Lice from family Echinophthiriidae are of the few insects that have successfully colonized marine environment living as ectoparasites of pinnipeds, i.e., sea lions, seals, and the walrus. They have developed unique adaptations to cope with the amphibious lifestyle of their hosts. Because eggs do not survive underwater, lice could only reproduce when their host remains on pack ice enough time. Consequently, lice generations per year are limited by host haul-out behavior. The objective of this work is to study the effect of host sex and age class, and the annual variation on the prevalence and mean abundance of Antarctophthirus lobodontis in crabeater seals from the Antarctic Peninsula. During three consecutive field-seasons, we collected lice from 41 crabeater seals (23 females, 16 males, 2 indeterminate, being 24 adults, and 17 juveniles). We investigated this effect on the prevalence and mean abundance by a generalized linear model formulation in a Bayesian framework. According to the lowest Deviance Index Criterion model, sex host does not affect prevalence nor mean abundance. We found that juveniles present greater abundance and prevalence than adults, possibly due to foraging habits. They spent more time on the ice than adults in groups of dozens of animals. This behavior would favor both egg development and lice transmission. We do not find adult females with lice, which suggests that transmission of A. lobodontis should be horizontal. The high mean abundance of lice in 2014 could be associated with an unusual increase in Lobodon carcinophaga population, probably related to the pack-ice availability and zooplankton abundance.

Lousy mums: patterns of vertical transmission of an amphibious louse.

In this study, we document patterns of vertical transmission of the amphibious louse Antarctophthirus microchir (Echinophthiriidae) in pups of South American sea lion, Otaria flavescens, from Patagonia. Vertical transmission is fundamental for the long-term stability of A. microchir populations because only pups stay long enough (1 month) on land for the louse to reproduce. A total of 72 pups ≤7 days old from a single rookery were captured and examined for lice. Infection parameters and population structure of A. microchir did not differ among pups collected at the beginning, middle, and end of the reproductive season, suggesting that patterns of early vertical transmission are not affected by the increase of rookery size during this period. Over 60% of 1-day-old pups were infected with A. microchir, and recruitment increased in pups up to 3 days old and then leveled off. In 1-day-old pups, significantly more adults than nymphs were found, but the pattern was reversed in older pups. The number of first-stage nymphs was significantly smaller than that of second- and third-stage nymphs, as it was the number of males vs. females, particularly in 1-day-old pups. Three non-exclusive hypotheses could account for these patterns, i.e., recruitment merely reflects the population structure of A. microchir is cows; the relative ability of lice to pass from cows onto pups increases in advanced instars; and/or natural selection favors transmission of adults, especially females, because they accrue greater fitness. The importance of latter hypothesis should not be underestimated in a species with a tight reproductive schedule.

Life begins when the sea lion is ashore: microhabitat use by a louse living on a diving mammal host.

Among Anoplura, the family Echinophthiriidae includes species that infest pinnipeds and otters. Previous evidence obtained from pinnipeds infested by echinophthiriids, specifically from seals, indicates that flippers are the preferred infestation sites, while lice from fur seals select areas in the pelage. We studied habitat selection of Antarctophthirus microchir on South American sea lion pups (Otaria flavescens Shaw, 1800) from Patagonia, Argentina, during the austral summer of 2009. We found a clear pattern of habitat selection: eggs are laid on the dorsal surface; nymphs 1 hatch there and then migrate to the belly, where they develop into adults and copulate; and then ovigerous females return to the dorsal surface. On the one hand, nymphs 1 are characterised by their low locomotory ability; therefore, the fact that they migrate as soon as they hatch suggests a clear pressure leading to microhabitat restriction. On the other hand, the described pattern of microhabitat selection seems to respond to the physiological requirements of each stage, which vary according to the physiological process considered, e.g. oviposition, morphogenesis, hatching and development. Accordingly, it appears that A. microchir would prefer the host's ventral area for development and copulation and the dorsal area for oviposition. However, the causes of this pattern are not clear, and many factors could be involved. Considering that sea lion pups periodically soak at high tides, and that prolonged immersion and very high humidity are known to be lethal for lice eggs, selecting the dorsal area would be advantageous for oviposition because it dries much faster. Furthermore, because humidity should be retained for longer periods on the ventral surface of the pup, wetter conditions on the sea lion would prevent desiccation of the nymphs in the very arid environment where O. flavescens breeds.

Population dynamics of Antarctophthirus microchir (Anoplura: Echinophthiriidae) in pups from South American sea lion, Otaria flavescens, in Northern Patagonia.

We analysed population dynamics of the louse Antarctophthirus microchir in pups of the South American sea lion, Otaria flavescens, at the Punta León rookery (Argentina) over a period of 2 years. A total of 136 pups were aged and marked at the beginning of the lactation period ashore, then sampled for lice at different times within 30 days. Sampling was restricted to the chest and belly, two sites where lice were especially abundant. This concentration on ventral areas might protect lice from thermal stress in the austral summer. Infestation patterns in pups 3 days old suggested that the potential for transmission increased from first nymphs to adults. Population trends of each instar with pup age, based on standardised values of abundance, were conserved between years, reflecting the basic dynamics of recruitment and reproduction. However, trends based on log-transformed abundances varied significantly between years; apparently, environmental conditions affected growth of lice populations differently each year. Stage-based deterministic models for population growth of A. microchir suggested generation times from 18 to 23 days. Accordingly, only 2 lice generations might be produced before pups start going to the sea. Shortening the cycle to accommodate a third generation might be risky, whereas a 2-generation cycle might at least result in larger females producing higher numbers of viable offspring.

Screening of tetanus antibodies with the aid of dot-enzyme-linked immunosorbent assay (Dot-ELISA). Validation of the results using standard ELISA and passive hemagglutination test.

A Dot-ELISA is described that lends itself to the screening of large series of sera in relation to tetanus antibodies. A threshold of 0.06 I.U. per ml has been chosen as representing the protective tetanus antibody level. Two hundred and fifty-four sera were assayed by conventional ELISA, passive hemagglutination test and Dot-ELISA. The results obtained using concurrently these 3 techniques were in agreement with one another and permitted us to ascribe the same sera as tested by the various techniques to the same group of sera containing a non protective antitetanus antibody level and to the same group of sera-containing a protective level. It is suggested that Dot-ELISA should be used for the assessment of the tetanus immune status of populations.

A dot-ELISA for the detection of IgG antibodies to mumps and varicella viruses.

An enzyme-linked immunosorbent assay using nitrocellulose strips (dot-ELISA) for the routine laboratory detection of IgG antibodies to mumps and varicella viruses is described. The virus antigens are dotted onto nitrocellulose strips, and the dotted strips are incubated with the sera to be tested. The bound antibodies are revealed using enzyme-labeled antihuman IgG antibodies. Reliable results are obtained when the assay is carried out at 37 degrees C. The reported data indicate that the dot-ELISA can reliably be used for the detection of IgG antibodies to mumps and varicella viruses in human sera.

A dot-ELISA intended for the specific and simultaneous detection of antibodies directed to antigens derived from Toxoplasma gondii, rubella virus, cytomegalovirus, and type 1 and type 2 herpesviruses.

A procedure for the routine and simultaneous laboratory detection of IgG antibodies produced in humans in the course of various infectious diseases is described. The procedure, based on dot-enzyme-linked immunosorbent assay (ELISA), used single nitrocellulose strips onto which several antigens were dotted in close proximity. Optimal conditions were specified that allowed the unequivocal and simultaneous detection of IgG antibodies specifically directed against Toxoplasma gondii, rubella virus, cytomegalovirus, and herpes simplex virus type 1 and type 2 antigens. This technique has proved to be simultaneously specific, sensitive, and reliable, and it has been applied to prenatal screening of sera from pregnant women. It is suggested that this technique should also be used for the screening of large numbers of sera under field trial conditions.

Rapid assessment of the antitetanus immune status of a subject using Dot-ELISA.

We describe a Dot-ELISA system for the rapid, specific and reliable assessment of a subject's antitetanus immune status. The conditions for Dot-ELISA were selected to give positive reactions only for sera with antitetanus antibody titers equal to or higher than 0.06 I.U./ml, considered to represent protection when using "in vitro" methods. This Dot-ELISA method could advantageously be applied to the monitoring of vaccination campaigns, as well as for assessing the antitetanus immune status of the wounded.

Dot-enzyme immunoassay for visual detection of Brucella melitensis antibodies.

An indirect enzyme-linked immunosorbent assay, using antigen coupled to paper, has been adapted for the detection of Brucella melitensis antibodies. Optimum conditions were achieved by incubation of 1 ml of diluted serum with a single piece of paper coated with purified Brucella antigens for a period of one hour, and by addition of a goat anti-human enzyme conjugate antibody for one hour again. Under these conditions 80 human sera were examined and the results obtained were compared with Wright agglutination test.

Influence of ceftizoxime on the immune system.

In the last few years the interest about the influence on host/parasite relations exerted by antibiotics has increased. In this study we have studied the effect of ceftizoxime, a third generation cephalosporin, on some functional parameters of human macrophages and granulocytes. Ceftizoxime does not seem to exert any stimulatory effect on phagocytosis and chemotaxis, but at the same time it allows these cells to explicate their functions during an infective process. A separate series of experiments was designed in order to investigate the immunogenicity of ceftizoxime and its immunological cross-reactivity versus other beta-lactam antibiotics. The low ELISA title of ceftizoxime indicates its weak immunogenic power. Cross-reactivity was also very low (title 1:25) when ceftizoxime was tested against the other antibiotics.

Rapid dot-immunobinding for detecting antibodies to Toxoplasma gondii in human serum.

A modified dot-immunobinding assay is described for the rapid, specific and reliable screening of human sera for Toxoplasma gondii immunity status. This simple, rapid and sensitive assay proved to be a practical diagnostic technique since it can be performed in 3 hours employing a small amount of antigen (0.3 micrograms/microliters).

Evaluation of anti-Listeria monocytogenes antibodies by ELISA.

A new ELISA test using the purified Listeria monocytogenes-derived antigen LM 84 Ag is described together with its application in the diagnosis of listeriosis. Fifty-seven human sera were titrated by the ELISA and the complement fixation method and compared for specificity and sensitivity. The problem of possible cross-reactions with other antigens is discussed.

The restoration of impaired macrophage functions using as immunomodulator the Corynebacterium granulosum-derived P40 fraction.

Many microorganisms and compounds of microbial origin exhibit immunomodulatory activities and have been extensively used in immunotherapy of experimental animal tumors and in patients with neoplasia. In this paper we describe the effect of the C. granulosum-derived P40 fraction on the growth and metastatization of the transplantable epithelioma T8 of Guèrin. Moreover, we evaluated the effect of P40 treatment on several depressed macrophage functions of tumor-bearing rats. In particular, the phagocytic and chemotactic activities of such cells were studied, as well as the antiviral intrinsic and extrinsic activities against HSV-1 and the anti-Toxoplasma gondii activity. All these functions were depressed in untreated tumor-bearing rats. Administration of a single intravenous injection of P40 fraction led to the restoration of all depressed macrophage activities to normal values. In particular, the possibility of restoring the antimicrobial activity of macrophages from tumor-bearing rats by treatment with this immunomodulator is of great concern when one considers the increasing incidence of opportunistic infections in immunocompromised hosts. Results are discussed in terms of both the possible mechanism of action of P40 and of its possible target cells.

[Evaluation of anti-HAV IgG on 2 samples of closed populations]. / Valutazione di IgG anti-HAV su due campioni di popolazione "chiusa".

The authors have carried out an epidemiologic research about the diffusion of antibody to hepatitis A antigen in the inhabitants of Ginostra, fraction of Stromboli, and Alicudi Islands (Eolie's arcipelago). We have examined by ELISA 86 human sera. We have detected a percentage of positivity about 82 and 70.6% for two populations. A critic examination of the results with parameters auxiliary (sex, age), showed significant differences of positivity about two different sexs and ages.

Enzyme-linked immunosorbent assay (ELISA) for streptokinase antibodies.

A micro plate Enzyme-linked immunosorbent assay (ELISA), developed for detection of antibodies to Streptokinase, was used to analyze 80 human sera. The aim was to provide a simple method for antibody screening that required neither sophisticated equipment nor a high degree of technological skill. Preliminary results show that ELISA is specific, reproducible and sensitive. Comparative evaluation of the ELISA and the coagulum lysis test for antibodies against streptokinase show excellent correlation. We also evaluated the anti-Streptolysin O titer either by conventional method or ELISA. The sensitivity of ELISA for detecting anti-Streptolysin O antibodies was 3-4-fold higher than that of the hemolytic test. The sensitivity of ELISA for detecting anti-streptokinase antibodies was 10-20-fold higher than that of the coagulum lysis. The Enzyme-linked immunosorbent assay seems to offer some advantages over the more commonly used coagulum lysis test as far as sensitivity is concerned and potentially it is suggested that this method could be usefully employed clinically in human streptococcal infections.