The influence of inhibitors of apoptosis proteins (IAPs) on chronic rhinosinusitis with nasal polyps.

BACKGROUND: Inhibitors of apoptosis proteins (IAPs) modulate the inflammatory process, and may facilitate the formation of chronic rhinosinusitis with nasal polyps (CRSwNP). This study aimed to observe if IAPs were differently expressed between patients with CRSwNP and controls, and to correlate the expression of IAPs with some inflammatory markers, as with the response to nasal corticosteroids in patients with CRSwNP. METHODOLOGY: We obtained nasal biopsies from patients with CRSwNP (n=27) and controls (n=16). qRT-PCR measured the expression of IAPs and caspases, while Luminex assay measured the concentration of cytokines. Unpaired parametric tests and Principal Component Analysis (PCA) were used for statistical analysis. RESULTS: We observed lower expression of IAP genes (XIAP, BIRC2/IAP1, and BIRC3/IAP2) in CRSwNP patients compared to controls, and we identified that patients with bad response to corticosteroids presented lower levels of BIRC2/IAP1, XIAP, BCL2, CASP9, and IL-17, and higher levels of CASP7 and TGF-B. CONCLUSIONS: IAPs expression was downregulated in CRSwNP, and was associated with poorer response to nasal corticosteroids. The present findings suggest the importance of IAPs as a link between environment and the host inflammatory responses, and this pathway could be explored as a potential new target therapy for patients with CRSwNP.

Smell loss associated with SARS-CoV-2 is not clinically different from other viruses: a multicenter cohort study.

BACKGROUND: Although the COVID-19 pandemic has increased the prevalence of cases with olfactory loss, other respiratory viruses can also cause this condition. We aimed to compare the prevalence of acute SARS-CoV-2 infection and other respiratory viruses in patients with sudden smell loss, and to assess the impact of SARS-CoV-2 viral load and co-infection on olfactory symptoms. METHODS: Patients with sudden smell loss were recruited in a multicenter prospective cohort study in 15 hospitals in Brazil. Clinical questionnaire, Connecticut Chemosensory Clinical Research Center (CCCRC) olfactory test and nasopharyngeal swab to perform a PCR-based respiratory viral panel were collected at first visit (day 0) and 30 and 60 days after recruitment. RESULTS: 188 of 213 patients presented positive test result for SARS-CoV-2, among which 65 were co-infected with other respiratory viruses (e.g., rhinovirus, enterovirus, and parainfluenza). 25 had negative test results for SARS-CoV-2. Patients in both SARSCoV-2 and non-SARS-CoV-2 groups had objective anosmia (less than 2 points according to the psychophysical olfactory CCCRC) at day 0, with no significant difference between them. Both groups had significant smell scores improvement after 30 and 60 days, with no difference between them. Co-infection with other respiratory viruses, and SARS-CoV-2 viral load did not impact olfactory scores. CONCLUSION: Patients with sudden smell loss associated with SARS-CoV-2 and other respiratory viruses had similar presentation, with most participants initiating with anosmia, and total or near total recovery after 60 days. SARS-CoV-2 viral load and co-infections with other respiratory viruses were not associated with poorer olfactory outcomes.

Experimental manipulation of humidity in a cavity-nesting bird influences ectoparasites' abundance.

Climate change effects on host­parasite interactions have been poorly studied in arid or semi-arid habitats. Here, we conducted an experiment aimed to increase the temperature inside European roller Coracias garrulus nest boxes located in a semi-arid habitat on different nest-site types to look for effects on different ectoparasite abundances and nestling growth. Average nest temperature was slightly higher in heated nests than in control nests, although differences were not statistically significant. However, relative humidity was significantly lower at night in heated nests as compared to control nests. The abundance of sand flies, mites and carnid flies was significantly higher in heated, less humid, nests while biting midge abundance was significantly lower in heated nests. Other ectoparasites were not significantly affected by treatment. Relative humidity was high even in heated nests, reaching more than 60%. Sand fly abundance was higher in nests located in sandstone walls, while mite abundance was higher in isolated farmhouses. In addition, sand fly prevalence was higher in nests located in isolated farmhouses and sandstone walls. Heat treatment, nest-site type or ectoparasite abundances did not affect the nestling body mass, wing length or their growth at different nestling ages.

miRNA-205-5p can be related to T2-polarity in Chronic Rhinosinusitis with Nasal Polyps.

BACKGROUND: microRNAs (miRNAs) are directly associated with inflammatory response, but their direct role in CRSwNP (chronic rhinosinusitis with nasal polyps) remains evasive. This study aimed to compare the expression of several miRNAs in tissue samples obtained from patients with CRSwNP and controls and to evaluate if miRNAs correlate to a specific inflammatory pattern (T1, T2, T17, and Treg) or intensity of symptoms in CRSwNP. METHODS: nasal polyps (from patients with CRSwNP - n=36) and middle turbinate mucosa (from control patients - n=41) were collected. Microarray determined human mature miRNA expression, and the results obtained were validated by qPCR. miRNAs that were differentially expressed were then correlated to cytokine proteins (by Luminex), tissue eosinophilia, and SNOT-22. RESULTS: After microarray and qPCR analyses, six microRNAs were up-regulated in CRSwNP samples when compared with controls: miR-205-5p, miR-221-3p, miR-222-3p, miR-378a-3p, miR-449a and miR-449b-5p. All these miRNAs are directly implicated with cell cycle regulation and apoptosis, and to a minor extent, with inflammation. Importantly, miR-205-5p showed a significantly positive correlation with IL-5 concentration and eosinophil count at the tissue and with the worst SNOT-22 score. CONCLUSIONS: miRNA 205-5p was increased in CRSwNP compared to controls, and it was especially expressed in CRSwNP patients with higher T2 inflammation (measured by both IL-5 levels and local eosinophilia) and worst clinical presentation. This miRNA may be an interesting target to be explored in patients with CRSwNP.

New viral biogeochemical roles revealed through metagenomic analysis of Lake Baikal.

BACKGROUND: Lake Baikal is the largest body of liquid freshwater on Earth. Previous studies have described the microbial composition of this habitat, but the viral communities from this ecosystem have not been characterized in detail. RESULTS: Here, we describe the viral diversity of this habitat across depth and seasonal gradients. We discovered 19,475 bona fide viral sequences, which are derived from viruses predicted to infect abundant and ecologically important taxa that reside in Lake Baikal, such as Nitrospirota, Methylophilaceae, and Crenarchaeota. Diversity analysis revealed significant changes in viral community composition between epipelagic and bathypelagic zones. Analysis of the gene content of individual viral populations allowed us to describe one of the first bacteriophages that infect Nitrospirota, and their extensive repertoire of auxiliary metabolic genes that might enhance carbon fixation through the reductive TCA cycle. We also described bacteriophages of methylotrophic bacteria with the potential to enhance methanol oxidation and the S-adenosyl-L-methionine cycle. CONCLUSIONS: These findings unraveled new ways by which viruses influence the carbon cycle in freshwater ecosystems, namely, by using auxiliary metabolic genes that act upon metabolisms of dark carbon fixation and methylotrophy. Therefore, our results shed light on the processes through which viruses can impact biogeochemical cycles of major ecological relevance. Video Abstract.

High-resolution structural insights into the heliorhodopsin family.

Rhodopsins are the most abundant light-harvesting proteins. A new family of rhodopsins, heliorhodopsins (HeRs), has recently been discovered. Unlike in the known rhodopsins, in HeRs the N termini face the cytoplasm. The function of HeRs remains unknown. We present the structures of the bacterial HeR-48C12 in two states at the resolution of 1.5 Å, which highlight its remarkable difference from all known rhodopsins. The interior of HeR's extracellular part is completely hydrophobic, while the cytoplasmic part comprises a cavity (Schiff base cavity [SBC]) surrounded by charged amino acids and containing a cluster of water molecules, presumably being a primary proton acceptor from the Schiff base. At acidic pH, a planar triangular molecule (acetate) is present in the SBC. Structure-based bioinformatic analysis identified 10 subfamilies of HeRs, suggesting their diverse biological functions. The structures and available data suggest an enzymatic activity of HeR-48C12 subfamily and their possible involvement in fundamental redox biological processes.

Charting the diversity of uncultured viruses of Archaea and Bacteria.

BACKGROUND: Viruses of Archaea and Bacteria are among the most abundant and diverse biological entities on Earth. Unraveling their biodiversity has been challenging due to methodological limitations. Recent advances in culture-independent techniques, such as metagenomics, shed light on the unknown viral diversity, revealing thousands of new viral nucleotide sequences at an unprecedented scale. However, these novel sequences have not been properly classified and the evolutionary associations between them were not resolved. RESULTS: Here, we performed phylogenomic analysis of nearly 200,000 viral nucleotide sequences to establish GL-UVAB: Genomic Lineages of Uncultured Viruses of Archaea and Bacteria. The pan-genome content of the identified lineages shed light on some of their infection strategies, potential to modulate host physiology, and mechanisms to escape host resistance systems. Furthermore, using GL-UVAB as a reference database for annotating metagenomes revealed elusive habitat distribution patterns of viral lineages and environmental drivers of community composition. CONCLUSIONS: These findings provide insights about the genomic diversity and ecology of viruses of prokaryotes. The source code used in these analyses is freely available at https://sourceforge.net/projects/gluvab/.

Regeneration of a keystone semiarid shrub over its range in Spain: habitat degradation overrides the positive effects of plant-animal mutualisms.

Global change drivers are currently affecting semiarid ecosystems. Because these ecosystems differ from others in biotic and abiotic filters, cues for plant regeneration and management derived from elsewhere may not be applicable to semiarid ecosystems. We sought to determine the extent to which regional variation in regeneration prospects of a long-lived semiarid keystone shrub depends on anthropogenic habitat degradation, plant-animal interactions and climate determinants. We investigated the regeneration ability (via population size structure, juvenile density and juvenile/adult ratio), fruit set and seed dispersal of Ziziphus lotus in 25 localities spanning the range of its threatened habitats in Spain. We dissected the relative contribution of different regeneration determinants using multiple regression and structural equation modelling. Population regeneration was extremely poor, and size structures were biased towards large classes and low juvenile densities and juvenile/adult ratios. Poor regeneration was often coincident with seed dispersal collapse. However, the positive effect of seed dispersal on population regeneration disappeared after considering its relationship with habitat degradation. Protected areas did have juveniles. Together, these data suggest that habitat degradation directly impacts juvenile establishment. Our results provide insights into habitat and species management at the regional level. Z. lotus populations are currently driven by persistence-based dynamics through the longevity of the species. Nonetheless, collapsed seed dispersal, poor regeneration and the removal of adults from their habitats forecast extinction of Z. lotus in many remnants. The extreme longevity of Z. lotus provides opportunities for recovery of its populations and habitats through effective enforcement of regulations.

Cephalometric, muscular and swallowing changes in patients with OSAS.

Obstructive Sleep Apnoea Syndrome (OSAS) is believed to be associated with craniofacial and neuromuscular changes, although the interplay among these variables still is poorly recognised. The objective of this study was to identify hyoid, muscular and swallowing changes associated with OSAS, and to correlate these alterations with OSAS severity. Cross-sectional study, in a tertiary referral centre. Seventy-two adult individuals participated in this study: 12 controls (without apnoea) and 60 patients with apnoea (mild, moderate and severe OSAS-20 individuals in each group). All participants were initially evaluated by otorhinolaryngologist and neurologist and underwent polysomnography for OSAS stratification. Cephalometric data, clinical myofunctional status and swallow videofluoroscopy exam were assessed. A hybrid effect model was used to analyse swallowing parameters; dependent variables were age, body mass index (BMI) and cephalometric measures. Individuals with OSAS presented lower hyoid position and narrower posterior airway distance when compared to controls. These parameters correlated to OSAS severity. Additionally, OSAS patients exhibited significantly lower myofunctional scores. Both velum and hyoid contraction times were significantly lower in the OSAS group at videofluoroscopy, regardless of its severity. Premature leakage into pharynx was more common in OSAS groups. Laryngeal penetration phenomenon occurred only in two patients (both from OSAS group). Our results suggest that hyoid bone position is associated with OSAS severity. Muscular pattern and swallowing are impaired in OSAS patients, irrespective of OSAS severity and facial profile. These findings indicate a higher predisposition of OSAS patients to present an inferior hyoid positioning, accompanied by myofunctional and swallowing disorders.

The pathogens profile in children with otitis media with effusion and adenoid hypertrophy.

OBJECTIVES: To evaluate the presence of viruses and bacteria in middle ear and adenoids of patients with and without otitis media with effusion (OME). METHODS: Adenoid samples and middle ear washes (MEW) were obtained from children with OME associated with adenoid hypertrophy undergoing adenoidectomy and tympanostomy, and compared to those obtained from patients undergoing cochlear implant surgery, as a control group. Specific DNA or RNA of 9 respiratory viruses (rhinovirus, influenza virus, picornavirus, syncytial respiratory virus, metapneumovirus, coronavirus, enterovirus, adenovirus and bocavirus) and 5 bacteria (S. pneumoniae, H. influenzae, M. catarrhalis, P. aeruginosa and S. aureus) were extracted and quantified by real-time PCR. RESULTS: 37 OME and 14 cochlear implant children were included in the study. At the adenoid, virus and bacteria were similarly detected in both OME and control patients. At the middle ear washes, however, a higher prevalence of bacteria was observed in patients with OME (p = 0.01). S. pneumoniae (p = 0.01) and M. catarrhalis (p = 0.022) were the bacteria responsible for this difference. Although total virus detection was not statistically different from controls at the middle ear washes (p = 0.065), adenovirus was detected in higher proportions in adenoid samples of OME patients than controls (p = 0.019). CONCLUSIONS: Despite both OME and control patients presented similar rates of viruses and bacteria at the adenoid, children with OME presented higher prevalence of S. pneumonia, M. catarrhalis in middle ear and adenovirus in adenoids when compared to controls. These findings could suggest that these pathogens could contribute to the fluid persistence in the middle ear.

Trimetilaminuria o «síndrome de olor a pescado»: ¿una entidad infradignosticada? / Trimethylaminuria or «the fish odor syndrome»: ¿under-diagnosed entity?

La trimetilaminuria o síndrome de olor a pescado es un trastorno metabólico, probablemente infradiagnosticado, caracterizado por un déficit de la enzima flavinmonooxigenasa 3. Dicho déficit ocasiona una excesiva acumulación de trimetilamina (TMA) en las secreciones corporales, causando un olor corporal similar al del pescado podrido. El diagnóstico de esta entidad se realiza mediante la cuantificación en orina de TMA y trimetilamina N-óxido, aunque actualmente se solicita directamente el estudio genético. El tratamiento no curativo se basa en dietas restringidas en precursores de TMA y pautas cortas de antibioterapia para paliar el olor corporal (AU)

Trimethylaminuria or the fish odor syndrome is a metabolic disorder, probably under-diagnosed, characterized by a failure in flavinmonooxigenase enzime. This failure provoques abnormal amount of TMA in body secretions, which can confers a body odor resembling rotting fish. The diagnosis of this entity is based on urine quantification of TMA and TMAO, although actually genetic study is directly requested. The non curative treatment is based on restricted diet of TMA precursors and short antibiotic pattern for body odor palliation (AU)

Morphological, molecular and phylogenetic analyses of the spirurid nematode Stegophorus macronectes (Johnston & Mawson, 1942).

Stegophorus macronectes (Johnston & Mawson, 1942) is a gastrointestinal parasite found in Antarctic seabirds. The original description of the species, which was based only on females, is poor and fragmented with some unclear diagnostic characters. This study provides new morphometric and molecular data on this previously poorly described parasite. Nuclear rDNA sequences (18S, 5.8S, 28S and internal transcribed spacer (ITS) regions) were isolated from S. macronectes specimens collected from the chinstrap penguin Pygoscelis antarctica Forster on Deception Island, Antarctica. Using 18S rDNA sequences, phylogenetic analyses (maximum likelihood, maximum parsimony and Bayesian inference) of the order Spirurida were performed to determine the phylogenetic location of this species. Primer pairs of the ITS regions were designed for genus-level identification of specimens, regardless of their cycle, as an alternative to coprological methods. The utility of this molecular method for identification of morphologically altered specimens is also discussed.

Tratamiento con óxido nítrico, levosimendán y sildenafilo en paciente con disfunción ventricular derecha e hipertensión pulmonar severa tras cirugía cardíaca / Nitrid oxide, levosimendan and sildenafile in a patient with right ventricle dysfunction and severe pulmonary hypertension after cardiac surgery

La hipertensión pulmonar (HTP), y como consecuencia la disfunción del ventrículo derecho, son importantes factores de riesgo de morbimortalidad en pacientes sometidos a cirugía cardíaca. El tratamiento de la HTP y la disfunción del ventrículo derecho debe ir enfocado a proteger la función cardíaca. Como objetivos principales del manejo hemodinámico se incluye mantener una adecuada precarga del ventrículo derecho, mejorar su función, reducir la poscarga del ventrículo derecho y las resistencias vasculares pulmonares con vasodilatadores. La terapia combinada con fármacos vasodilatadores que presentan diferentes mecanismos de acción es una opción terapéutica emergente en el tratamiento de la HTP. Presentamos el caso de una mujer de 65 años diagnosticada de insuficiencia mitral, aórtica, tricuspídea y con una dilatación de aorta ascendente con HTP sistólica de 115 mmHg estimada mediante ecografía. Se le practicó una plastia mitral, aórtica, tricuspídea y una aortoplastia. En el perioperatorio presentó disfunción del ventrículo derecho e HTP, siendo tratada con óxido nítrico, sildenafilo intravenoso y levosimendán. La evolución fue satisfactoria, manteniéndose el control de la funcionalidad cardíaca y de la HTP sin presentar fenómenos de hipotensión arterial sistémica ni alteraciones respiratorias relevantes (AU)

Pulmonary hypertension (PHT) and the resulting right ventricle dysfunction are important risk factors in patients who undergo cardiac surgery. The treatment of PHT and right ventricle dysfunction should be focused on maintaining the correct right ventricle after load, improving right ventricle function and reducing the right ventricle pre-load and therefore reducing pulmonary vascular resistance by means of vasodilators. A combined therapy of vasodilators and medicines which have different mechanisms of action, is becoming an option for the treatment of PHT. We present a 65 year old woman that suffered from mitral regurgitation, aortic valve disease, tricuspid and ascending aortic dilation with 115 mmHg of pulmonary artery pressure (by ultrasound evaluation). The patient was operated on of mitral, aortic valve and tricuspid plastia and proximal aortic artery plastia as well. Previosly to surgery the patient suffered right ventricle dysfunction and PHT and was treated with nitric oxide, intravenous sildenafil and levosimendan. Subsequent evolution was satisfactory, PHT being controlled, without arterial hypotension nor respiratory alterations (AU)

Hypertrophic adenoid is a major infection site of human bocavirus 1.

Human bocavirus 1 (HBoV1) is associated with respiratory infections worldwide, mainly in children. Similar to other parvoviruses, it is believed that HBoV1 can persist for long periods of time in humans, probably through maintaining concatemers of the virus single-stranded DNA genome in the nuclei of infected cells. Recently, HBoV-1 was detected in high rates in adenoid and palatine tonsils samples from patients with chronic adenotonsillar diseases, but nothing is known about the virus replication levels in those tissues. A 3-year prospective hospital-based study was conducted to detect and quantify HBoV1 DNA and mRNAs in samples of the adenoids (AD), palatine tonsils (PT), nasopharyngeal secretions (NPS), and peripheral blood (PB) from patients undergoing tonsillectomy for tonsillar hypertrophy or recurrent tonsillitis. HBoV1 was detected in 25.3% of the AD samples, while the rates of detection in the PT, NPS, and PB samples were 7.2%, 10.5%, and 1.7%, respectively. The viral loads were higher in AD samples, and 27.3% of the patients with HBoV had mRNA detectable in this tissue. High viral loads and detectable mRNA in the AD were associated with HBoV1 detection in the other sample sites. The adenoids are an important site of HBoV1 replication and persistence in children with tonsillar hypertrophy. The adenoids contain high HBoV1 loads and are frequently positive for HBoV mRNA, and this is associated with the detection of HBoV1 in secretions.

Cavity types and microclimate: implications for ecological, evolutionary, and conservation studies.

The abiotic conditions of the immediate environment of organisms are key factors for a better understanding of ecological and evolutionary processes. Yet, information in this regard is biased towards some habitat types, landscapes, and organisms. Here, we present a 2-year comparative study of the microclimatic properties (temperature, relative humidity, and their fluctuation) of three cavity types (nest boxes, cavities in bridges, and burrows in sandy cliffs) in an arid environment. We found marked and consistent months-long differences in microclimate among the three cavity types. Nest boxes were colder than the other cavity types, with temperature oscillations being an order of magnitude higher than in other cavity types. In contrast, microclimate was very stable in burrows and cavities in bridges, the former being generally warmer and drier than the latter. We also discuss the biological implications of microclimatic conditions and its variation in different cavity types by presenting two case studies, namely the temperature-humidity index and water vapor pressure during the hatching period of an endotherm and the chilling period during the diapause of an ectotherm ectoparasite. We stress the need for comparative studies of the same organisms subjected to different microclimates given the important ecological, evolutionary, and conservation implications.

[Nitrid oxide, levosimendan and sildenafile in a patient with right ventricle dysfunction and severe pulmonary hypertension after cardiac surgery]. / Tratamiento con óxido nítrico, levosimendán y sildenafilo en paciente con disfunción ventricular derecha e hipertensión pulmonar severa tras cirugía cardíaca.

Pulmonary hypertension (PHT) and the resulting right ventricle dysfunction are important risk factors in patients who undergo cardiac surgery. The treatment of PHT and right ventricle dysfunction should be focused on maintaining the correct right ventricle after load, improving right ventricle function and reducing the right ventricle pre-load and therefore reducing pulmonary vascular resistance by means of vasodilators. A combined therapy of vasodilators and medicines which have different mechanisms of action, is becoming an option for the treatment of PHT. We present a 65 year old woman that suffered from mitral regurgitation, aortic valve disease, tricuspid and ascending aortic dilation with 115mmHg of pulmonary artery pressure (by ultrasound evaluation). The patient was operated on of mitral, aortic valve and tricuspid plastia and proximal aortic artery plastia as well. Previosly to surgery the patient suffered right ventricle dysfunction and PHT and was treated with nitric oxide, intravenous sildenafil and levosimendan. Subsequent evolution was satisfactory, PHT being controlled, without arterial hypotension nor respiratory alterations.

Temperature during the free-living phase of an ectoparasite influences the emergence pattern of the infective phase.

Understanding the population dynamics and co-evolution of host­parasite systems requires detailed knowledge of their phenology which, in turn, requires a deep knowledge of the effect of abiotic factors on the life cycles of organisms. Temperature is known to be a key environmental influence that participates in the regulation of diapause. Yet, not much is known about the effect of temperature on the free-living stages of true parasites and how it may influence host­parasite interactions. Here we experimentally study the effect of ambient temperature on overwintering pupae of Carnus hemapterus (Diptera, Carnidae), an ectoparasitic fly of various bird species. We also test whether chilling is a prerequisite for completion of diapause in this species. In the course of three winter seasons we experimentally exposed carnid pupae from nests of various host species to spring temperatures with and without chilling and recorded the emergence patterns in experimental and control groups. Experimental groups showed an advanced emergence date, a lower emergence rate and, consequently, a protracted emergence period. Chilling had no obvious effect on the start of emergence but it did advance the mean emergence date, shortened the length of the emergence period when compared with the control treatment and increased the emergence rate when compared with the spring treatment. This study identifies an environmental cue, namely temperature during the free-living stage, affecting the emergence of a widespread parasite and demonstrates the plasticity of diapause in this parasite. Our findings are of potential significance in understanding host­parasite interactions.

Mixed life-history strategies in a local population of the ectoparasitic fly Carnus hemapterus.

A major issue for the proper understanding of the evolution of life-cycle histories is the regulation of voltinism and its variation. Diapause characteristics are known to regulate voltinism, but the underlying mechanisms are poorly understood. This paper studies diapause duration and voltinism variation in a haematophagous diptera parasitizing 2 sympatric hosts with very different breeding phenologies. We hypothesize that bivoltinism will be more frequent in carnid flies parasitizing an early breeding, multi-brooded species than in flies parasitizing a late breeder, single-brooded species. We obtained evidence of the co-occurrence of uni- and bivoltinism in both clutches of the multi-brooded Spotless starling (Sturnus unicolor) as well as in clutches of the single-brooded European roller (Coracias garrulus). Unexpectedly, the proportion of bivoltine flies was similar in both host species. A remarkable degree of host-parasite synchronization at the population level was found for bivoltine flies. Our findings reveal the facultative nature of diapause in Carnus. We discuss the influence of abiotic conditions and host availability on polymorphism in life-history cycles and the consequences both for the parasite and the host.

Gastrointestinal parasites in Chinstrap Penguins from Deception Island, South Shetlands, Antarctica.

Knowledge about parasites of Antarctic birds is fragmented and scarce. The aim of this work is to contribute to the knowledge of gastrointestinal parasites of the Chinstrap Penguin (Pygoscelis antarctica) from Deception Island (South Shetlands, Antarctica). Gastrointestinal tracts of 64 fresh dead individuals (61 chicks and three adults) were collected from December 2006 to February 2009 and examined for macroparasites. Three adult parasite species were found: two Cestoda species (Parorchites zederi and Tetrabothrius pauliani) and one Nematoda species (Stegophorus macronectes). Also, immature acanthocephalans (Corynosoma sp.) were found in one penguin. The low parasite richness observed could be related to the stenophagic and pelagic diet of the host species. False negatives were found in coprological studies.

Experimental assessment of the effects of gastrointestinal parasites on offspring quality in chinstrap penguins (Pygoscelis antarctica).

Parasites reduce host fitness and consequently impose strong selection pressures on their hosts. It has been hypothesized that parasites are scarcer and their overall effect on hosts is weaker at higher latitudes. Although Antarctic birds have relatively low numbers of parasites, their effect on host fitness has rarely been investigated. The effect of helminth parasitism on growth rate was experimentally studied in chinstrap penguin (Pygoscelis antarctica) nestlings. In a total of 22 two-nestling broods, 1 nestling was treated with anthelminthics (for cestodes and nematodes) while its sibling was left as a control. Increased growth rate was predicted in de-wormed nestlings compared to their siblings. As expected, 15 days after treatment, the experimental nestlings had increased body mass more than their siblings. These results show a non-negligible negative effect of helminth parasites on nestling body condition that would presumably affect future survival and thus fitness, and it has been suggested there is a strong relationship between body mass and mortality in chinstrap penguins.