Mapping a brain parasite: Occurrence and spatial distribution in fish encephalon

Parasites, especially brain-encysting trematodes, can have an impact on host behaviour, facilitating the transmission to next host and completion of the life cycle, but insufficient research has been done on whether specific brain regions are targeted. Using Cardiocephaloides longicollis as a laboratory model, the precise distribution of metacercariae in experimentally-infected, wild and farmed fish was mapped. The brain regions targeted by this parasite were explored, also from a histologic perspective, and potential pathogenic effects were evaluated. Experimental infections allowed to reproduce the natural infection intensity of C. longicollis, with four times higher infection intensity at the higher dose (150 vs 50 cercariae). The observed metacercarial distribution, similar among all fish groups, may reflect a trematode species-specific pattern: metacercariae occur with highest density in the optic lobe area (primarily infecting the periventricular gray zone of optic tectum) and the medulla oblongata, whereas other areas such as the olfactory lobes and cerebellar lobes may be occupied when the more frequently invaded parts of the brain were crowded. Mono- and multicysts (i.e. formed either with a single metacercaria, or with 2-25 metacercariae encapsulated together) may be formed depending on the aggregation and timing of metacercariae arrival, with minor host inflammatory response. Larvae of C. longicollis colonizing specific brain areas may have an effect on the functions associated with these areas, which are generally related to sensory and motor functions, but are also related to other host fitness traits such as school maintenance or recognition of predators. The detailed information on the extent and distribution of C. longicollis in fish encephalon sets the ground to understand the effects of brain parasites on fish, but further investigation to establish if C. longicollis, through purely mechanical damage (e.g., occupation, pressure and displacement), has an actual impact on host behaviour remains to be tested under controlled experimental conditions.

Genetic variation of Sparicotyle chrysophrii (Monogenea: Microcotylidae) from the gilthead sea bream Sparus aurata (Teleostei: Sparidae) in the Mediterranean Sea

The gill monogenean Sparicotyle chrysophrii (Van Beneden & Hesse, 1863) Mamaev, 1984 is a specific and common parasite of wild and cultured gilthead sea bream Sparus aurata Linnaeus, 1758, able to cause disease and mortality in aquaculture systems. Few molecular studies have been carried out on this monogenean, and its population structure and genetic diversity are barely known. This study provides the first contribution to the population genetic variation of S. chrysophrii, based on two molecular markers - the structural ribosomal RNA (rRNA) for the large subunit (28S) and the cytochrome c oxidase subunit I (COI) gene. Samples were collected from the gills of farmed and wild S. aurata from Italy and the Spanish Mediterranean. The analysis included previously published sequences. The 28S rDNA analysis was consistent with previous studies of specimens isolated from S. aurata and confirmed the presence of only one species on the gills of this host in the Mediterranean Sea. The COI sequences analysis suggested that the samples isolated in a previous study from a different host species, wild Boops boops (Linnaeus, 1758) in the Adriatic Sea, may represent a new undescribed sister species of S. chrysophrii. The low nucleotide diversity of S. chrysophrii isolated only from S. aurata versus the high haplotype diversity revealed small differences between haplotypes. The haplotypes shared between wild and farmed hosts from Spain provided the first molecular evidence of the possible transfer of S. chrysophrii between wild and farmed populations of S. aurata. The mtDNA COI analysis did not show a clear genetic structure, probably the result of several factors including coevolution, wild and farmed host interactions, and host population structure in space and time.

Cohort profile: the ESC EURObservational Research Programme Non-ST-segment elevation myocardial infraction (NSTEMI) Registry

AIMS

The European Society of Cardiology (ESC) EURObservational Research Programme (EORP) Non-ST-segment elevation myocardial infarction (NSTEMI) Registry aims to identify international patterns in NSTEMI management in clinical practice and outcomes against the 2015 ESC Guidelines for the management of acute coronary syndromes in patients presenting without ST-segment-elevation.

METHODS AND RESULTS

Consecutively hospitalised adult NSTEMI patients (n = 3620) were enrolled between 11 March 2019 and 6 March 2021, and individual patient data prospectively collected at 287 centres in 59 participating countries during a two-week enrolment period per centre. The registry collected data relating to baseline characteristics, major outcomes (in-hospital death, acute heart failure, cardiogenic shock, bleeding, stroke/transient ischaemic attack, and 30-day mortality) and guideline-recommended NSTEMI care interventions: electrocardiogram pre- or in-hospital, pre-hospitalization receipt of aspirin, echocardiography, coronary angiography, referral to cardiac rehabilitation, smoking cessation advice, dietary advice, and prescription on discharge of aspirin, P2Y12 inhibition, angiotensin converting enzyme inhibitor (ACEi)/angiotensin receptor blocker (ARB), beta-blocker, and statin.

CONCLUSION

The EORP NSTEMI Registry is an international, prospective registry of care and outcomes of patients treated for NSTEMI, which will provide unique insights into the contemporary management of hospitalised NSTEMI patients, compliance with ESC 2015 NSTEMI Guidelines, and identify potential barriers to optimal management of this common clinical presentation associated with significant morbidity and mortality.

Genetic diversity of wild rodents and detection of Coxiella burnetii, the causative agent of Q fever, in Saudi Arabia

Throughout history, wildlife has been regarded as a major source of infectious diseases. Rodentia, the most speciose order of mammals, whose members are recognised hosts of more than 60 zoonotic diseases, represent a potential threat to human health. Recently, epidemiological data from Saudi Arabia indicated an actual growth in the number of emerging and/or re-emerging cases of several zoonoses. However, there is a lack of studies focusing on the molecular taxonomy of rodents and the pathogens they may harbour in this region. In this study, the first molecular characterisation of six rodent taxa in this region is provided, based on partial Cyt B and 16S genes. The data confirm the spread of rodent-associated C. burnetii strains in Jazan, southwestern Saudi Arabia. The PCR targeting IS111, the multi-copy transposase gene, revealed 17.5% (36/205) positive samples, whereas the second nested PCR, targeting the single-copy Com1 gene, revealed 16.6% (34/205) positive samples. Phylogenetic and network analyses indicated the presence of four haplotypes of C. burnetii within the studied localities. One major haplotype (H-2) was observed in all rodent species and from 18 localities. The infection rates of C. burnetii among studied species, localities and habitats were not significantly different (>0.05). Our results facilitate the assessment of the health risk associated with rodents and the development of strategies to control the increasing impacts of Q fever.

Morphological and molecular study of Didymodiclinus marginati n. sp. (Trematoda: Didymozoidae) gill parasite of Epinephelus marginatus from the central and western Mediterranean Sea

The current study provides a morphological and molecular characterization of a new species of Didymodiclinus (Trematoda: Didymozoidae) infecting the dusky grouper, Epinephelus marginatus (Teleostei: Serranidae) from the Mediterranean Sea. A total of 279 dusky grouper specimens were examined for didymozoid gill parasites from the Mediterranean Sea between 1998 and 2020. New species differs from the most similar congeneric species by the rudiments of female reproductive organs in functional male specimens, and the seminal receptacle, Mehlis gland and accessory gland cells in functional female specimens, not observed in Didymodiclinus branchialis (Yamaguti, 1970), Didymodiclinus epinepheli (Abdul-Salam, Sreelatha and Farah, 1990) and Didymodiclinus pacificus (Yamaguti, 1938), respectively. These species are also characterized by their different hosts and location within the host tissues, being from other geographical localities. Moreover, this is the first species reported in E. marginatus from the central and western Mediterranean Sea. Genetic analyses were performed on partial 28S and partial internal transcribed spacer-2 ribosomal RNA regions and the mitochondrial cytochrome oxidase 1 (cox1) gene by polymerase chain reaction. Comparison of genetic sequences of Didymodiclinus marginati n. sp. with the available deposited sequences of 28S revealed that the new isolates cluster with several unidentified didymozoids and groups as a sister clade of the Nematobothrinae subfamily. Moreover, 28S and cox1 phylogenetic trees evidenced that Didymodiclinae is well separated from Didymozoinae and other gonochoric didymozoids. Following both morphological and genetic results, a key of identification for the genus Didymodiclinus is proposed.

Stages of Granulomatous Response Against Histozoic Metazoan Parasites in Mullets (Osteichthyes: Mugilidae)

Simple Summary

Parasitic diseases represent a common issue in fish and, when histozoic forms are present, this elicits a chronic inflammatory reaction leading to granuloma formation. Despite the large knowledge of granuloma formation due to parasites in visceral organs, little is known about the development and the evolutive stages of granulomas in naturally infected fish. Mullets (Osteichthyes: Mugilidae) are a widespread euryhaline fish species that harbor different parasites, thus representing a suitable model for the study of parasite-induced granulomas. Combining histopathology and immunohistochemical tools, we identified three developmental granuloma stages (pre-granuloma, intermediate, and late stage), that ranged from an intact parasite with mild signs of tissue reaction to the formation of a structured granuloma. The identified histological patterns could be reliable tools in the staging of the granulomatous response associated with histozoic parasites and are an attempt to broaden the knowledge of the inflammatory response in different host–parasite systems.

Abstract

Histozoic parasite–fish host interaction is a dynamic process that leads to the formation of a granuloma, a specific chronic inflammatory response with discernible histological features. Mullets (Osteichthyes: Mugilidae) represent a suitable model concerning the development of such lesions in the host–parasite interface. The present work aimed to identify granuloma developmental stages from the early to the late phase of the infection and to characterize the immune cells and non-inflammatory components of the granuloma in different stages. For this purpose, 239 mullets were collected from 4 Sardinian lagoons, and several organs were examined by combining histopathological, bacteriological, and immunohistochemical methods. Granulomas associated with trematode metacercariae and myxozoan parasites were classified into three developmental stages: (1) pre-granuloma stage, characterized by intact encysted parasite and with no or mild tissue reaction; (2) intermediate stage, with partially degenerated parasites, necrosis, and a moderate number of epithelioid cells (ECs); and (3) late stage, with a necrotic core and no detectable parasite with a high number of ECs and fibroblasts. The three-tier staging and the proposed morphological diagnosis make it conceivable that histopathology could be an essential tool to evaluate the granulomas associated with histozoic parasitic infection in fish.

Cardicola mediterraneus n. sp. (Trematoda, Aporocotylidae): a new species infecting the gilthead seabream, Sparus aurata L., from the Western Mediterranean Sea

The genus Cardicola Short, 1953 has the highest number of species within the family Aporocotylidae (Trematoda: Digenea). Five Cardicola species have been reported to date in the Mediterranean Sea, one of them in the gilthead seabream Sparus aurata L. Analyses of infected S. aurata recovered from cultured fish off Sardinia (Italy) and from wild and cultured fish off the Levantine coast (Southeastern Spain) have revealed the presence of two species identified as Cardicola aurata Holzer, Montero, Repullés, Nolan, Sitjà-Bobadilla, Álvarez-Pellitero, Zarza and Raga, 2008 and Cardicola mediterraneus n. sp.. New morphological and molecular data are provided for both species. Features of C. aurata specimens differ slightly from those of the original description of the species, the most important differences being the longer extension of the metraterm and the central and posterior position of the female genital pore. Cardicola mediterraneus n. sp. can be easily distinguished from other Cardicola species by two unique specific characters: (i) the very unequal posterior caeca length and (ii) the shape of the testis, deeply notched at the anterior extremity. Cardicola spp. from sparids occupy a basal phylogenetic position respect the other congeneric species. The genus Cardicola has a complex taxonomy and shows high intrageneric differences for both 28S and ITS2 rDNAs, similar to the intergeneric differences among other aporocotylid genera, suggesting that it could be split. The presence of two Cardicola species could hamper treatment design and application; thus, data discriminating species herein reported can improve the infection management in fish farms.

851Predictors and causes of inappropriate shocks by subcutaneous defibrillators (S-ICD) in a cohort of sardinian Brugada syndrome patients

Funding Acknowledgements

Project Code CRP- 6175. Regione Autonoma della Sardegna

Background

The subcutaneous defibrillator (S-ICD) is an attractive option for patients with Brugada syndrome (BrS) at high risk, as it is highly effective to prevent arrhythmic sudden cardiac death (SCD) while avoiding some of the complications associated to transvenous devices. However, S-ICD are not free from complications, one of the most common being inappropriate shocks.

Objective

To assess the causes and predictors of inappropriate shocks by subcutaneous defibrillators (S-ICD) in a cohort of sardinian BrS patients

Methods

From February 2013 to September 2019, 373 patients were diagnosed as BrS patients. Sixty-five patients were considered to be at high risk of SCD, and implanted with an ICD. Of them, 36 were implanted with an S-ICD. Patients went through regular follow-up visits (physical examination, 12-lead ECG, device interrogation, occurrence of symptoms). Appropriate and inappropriate shocks were analyzed to establish their cause.

Results

Thirty-six BrS patients were implanted with an S-ICD (9.7% of the total BrS group, 55% of ICD implants). Twenty-four patients (67%) were male, mean age at diagnosis was 45± 14 y.o., and 31 (86%) were probands.  Seventeen patients (47%) had a family history of SCD. Ten patients (28%) had a spontaneous type 1 ECG at diagnosis and 14 (19%) had an spontaneous type 1 ECG at least once since the diagnosis , 2 patients (5.7%) had a type 1 ECG during fever, and 11 (31%) presented an S wave ≥40 msec in lead DI. Twelve patients (33%) underwent EP study, and 8 (67%) were inducible for ventricular fibrillation.

During a mean follow-up of 46 ± 67 months, 2 patients (6%) had appropriate shocks, while 5 (14%) had inappropriate shocks. The rate between inappropriate and appropriate shock was 2.5.  The causes of inappropriate shock were T-wave oversensing (4 patients, 80%) and air entrapment (1 patient, 20%).

Gender, proband status, sport practice, family history of SCD, type 1 ECG during fever, S wave ≥40 msec in lead DI, VF inducibility EP study, or the presence of symptoms during the follow-up (vaso-vagal syncope, arrhythmic syncope, nocturnal enuresis, ventricular fibrillation, atrial fibrillation) did not associated with inappropriate shock; neither did the technique of screening for S-ICD (manual or automated tool) nor the selected vector of sensing of the S-ICD.

A spontaneous type 1 ECG at diagnosis (4 (80%) versus 6 (21%), p = 0.009), or at any time from diagnosis during follow-up (4 (80%) versus 10 (33%), p = 0.0049) and having a high-pass filter programmed OFF/not available [3 (75% versus 7 (25%), p = 0.044], were significantly associated with inappropriate shock of S-ICD in these population.

Conclusions

Brugada syndrome patients implanted with S-ICD present a higher rate of inappropriate shock compared to appropriate shock (2.5 times). Patients with spontaneous type 1 ECG are at  higher risk to receive inappropriate shock from S-ICDs, while programming a high-pass filter ON may prevent some of these episodes.

Determination of Praziquantel in Sparus aurata L. after Administration of Medicated Animal Feed

Simple Summary

The present study aimed to determine the praziquantel concentration in Sparus aurata muscle after oral administration of medicated feed. The in-feed treatment is commonly used in aquaculture breeding because it allows the treatment of a large fish population without stress. However, no residue limit exists for praziquantel in fish for human consumption, so the purpose of this work was to verify if this drug was able to accumulate in fish tissues after this treatment. The high-sensitivity analytical method developed in this work permitted to identify and quantify low concentrations of the drug in gilthead sea bream muscle, after the above-mentioned treatment. This method can be useful to competent authorities in evaluating the appropriate withdrawal time in fish treated with praziquantel and intended for human consumption.

Abstract

Praziquantel (PZQ) is an anthelmintic drug used in humans and animals against Platyhelminthes and in aquaculture in the Far East. Medicated feed is one of the most convenient forms of oral administration of drugs in aquaculture because it allows to treat a large population of fish in an easy way. However, this treatment may lead to residues in fish intended for human consumption. In this study, a liquid chromatography with tandem mass spectrometry (LC-MS/MS) method was developed in order to verify the presence of PZQ in samples of Sparus aurata after oral administration of feed treated with PZQ. The method was validated according to international guidelines. It showed good recoveries, selectivity and sensitivity (LOD and LOQ were 3.0 and 9.3 ng/g, respectively), with precision and matrix effect values ≤ 15%. This method could also be applied to determine PZQ residue in other fish species and thus to evaluate the appropriate withdrawal time in treated fish intended for human consumption.

Multilocus approach reveals discordant molecular markers and corridors for gene flow between North African populations of Fasciola hepatica

Fasciolosis is a foodborne trematodosis characterised by a worldwide distribution. Various approaches have been developed for the study of the causative agents of this parasitic infection: Fasciola hepatica, Fasciola gigantica and the aspermic intermediated forms (hybrid and introgressed). In the present study, novel and common molecular markers (pepck and pold, ITS, CO1, ND1 and CO1-trnT-rrnL) were used to characterise Fasciola flukes from the Tunisian-Algerian border, to estimate the gene flow between these populations and to evaluate the reliability of different molecular markers. All nuclear and mitochondrial markers, apart from pepck, supported the monophyly of the studied flukes identified as F. hepatica. Multiplex PCR for pepck revealed three different genotypes corresponding to F. hepatica (pepck-Fh), F. gigantica (pepck-Fg) and the aspermic Fasciola flukes (pepck-Fh/Fg). Sequence analysis of pepck revealed high polymorphism, length variation, within this intronic marker. The observed inconsistencies were due to the position of the forward primer within the intronic region. Pepck sequences showed different level of heterozygosity and homozygosity with length polymorphisms in the introns. Pepck multiplex PCR patterns could not differentiate between Fasciola species. All studies based on only pepck multiplex PCR with mitochondrial markers should be revised. Nuclear and mitochondrial markers revealed an important gene flow between Tunisian and Algerian populations of F. hepatica. The combination of nuclear and mitochondrial sequence analysis is still the best method to distinguish these taxa. Effective measures are needed in order to better control cross-country illegal trade of vector.

The ESC ACCA EAPCI EORP acute coronary syndrome ST-elevation myocardial infarction registry

Aims 

The Acute Cardiac Care Association (ACCA)–European Association of Percutaneous Coronary Intervention (EAPCI) Registry on ST-elevation myocardial infarction (STEMI) of the EurObservational programme (EORP) of the European Society of Cardiology (ESC) registry aimed to determine the current state of the use of reperfusion therapy in ESC member and ESC affiliated countries and the adherence to ESC STEMI guidelines in patients with STEMI.

Methods and results 

Between 1 January 2015 and 31 March 2018, a total of 11 462 patients admitted with an initial diagnosis of STEMI according to the 2012 ESC STEMI guidelines were enrolled. Individual patient data were collected across 196 centres and 29 countries. Among the centres, there were 136 percutaneous coronary intervention centres and 91 with cardiac surgery on-site. The majority of centres (129/196) were part of a STEMI network. The main objective of this study was to describe the demographic, clinical, and angiographic characteristics of patients with STEMI. Other objectives include to assess management patterns and in particular the current use of reperfusion therapies and to evaluate how recommendations of most recent STEMI European guidelines regarding reperfusion therapies and adjunctive pharmacological and non-pharmacological treatments are adopted in clinical practice and how their application can impact on patients’ outcomes. Patients will be followed for 1 year after admission.

Conclusion 

The ESC ACCA-EAPCI EORP ACS STEMI registry is an international registry of care and outcomes of patients hospitalized with STEMI. It will provide insights into the contemporary patient profile, management patterns, and 1-year outcome of patients with STEMI.

New insight into genetic variation and haplotype diversity of Fasciola hepatica from Algeria

The liver fluke Fasciola hepatica is the main cause of fasciolosis in North Africa leading to significant economic losses and public health problems. In this study, the ribosomal internal transcribed spacer (ITS), cytochrome c oxidase I (COI), the mitochondrial region spanning the COI-trnT-rrnL, and the NADH dehydrogenase subunit I (NADI) markers were used to characterize Fasciola flukes from Algeria. Fasciola appeared widespread from the east to the west of Algeria. Among 1701 sampled cattle from 8 Algerian provinces, 5% were infected. Using morphological and morphometric analysis, one morphotype of Fasciola was observed. Nuclear ITS marker indicated that all collected flukes belong to F. hepatica. Multiple alignments of ITS dataset revealed two haplotypes, one described here for the first time. Analysis of molecular variance (AMOVA) of mitochondrial markers revealed weak population structure in Algeria. Mismatch distributions, neutrality tests, and median-joining network analysis all were compatible with a recent expansion of Algerian F. hepatica population. Fasciolosis appeared common in Algerian cattle, it seems that the absence of control strategy coupled to the favorable Mediterranean climate may lead to a reconstruction and dispersion of its populations. This study provides important results concerning the genetic characterization and variability of F. hepatica in Algeria as well as the significant role of cattle importation in shaping its dispersal route worldwide.

Description of epithelial granular cell in catshark spiral intestine: Immunohistochemistry and ultrastructure

We evaluated the histology of the spiral intestine of the blackmouth catshark (Galeus melastomus), a small shark distributed in the eastern Atlantic and Mediterranean Sea basin. Entire digestive tracts of 10 G. melastomus were studied using histochemical, immunohistochemical, and ultrastructural methods. Our studies identified a unique, large granular cell type in the intestinal epithelium. Transmission electron microscopy showed that the epithelial granular cell type made intimate contact, by means of junctional complexes, with adjacent epithelial and mucous cells. Several histochemical staining methods showed that the cytoplasmic granules were strongly eosinophilic. Immunostaining of intestinal sections revealed immunoreactivity of the granular cell to tumor necrosis factor-α (TNF-α) antibody. However, no reactivity to inducible-nitric oxide synthase (i-NOS), interleukin-6 (IL-6), interleukin IL-1β, lysozyme, serotonin 5-HT antibodies was detected.

Ecological and histopathological aspects of Didymodiclinus sp. (Trematoda: Didymozoidae) parasite of the dusky grouper, Epinephelus marginatus (Osteichthyes: Serranidae), from the western Mediterranean Sea

The dusky grouper Epinephelus marginatus (Lowe) is an ecologically and commercially important fish species of the Atlantic and Mediterranean coastal rocky habitats. Despite records of didymozoid infections in several grouper species, the identification and pathogenesis of these parasites in E. marginatus are lacking. The aim of this study is to characterize the didymozoids of E. marginatus, particularly their mechanisms of infection and histopathological features. Dusky groupers (n = 205) were caught off Majorca Island (western Mediterranean Sea) and examined for parasites. Of the fish sampled, 45% were infected with white and yellow didymozoid capsules and brown nodules, found on the gills and pseudobranchs. Parasite abundance had a strong positive relationship with the fish length; only fish larger than 20 cm were infected, suggesting infection via consumption of an intermediate host, for which E. marginatus size was a limiting factor. The capsules contained two convoluted viable adult trematodes, identified as Didymodiclinus sp., in close contact with host capillary vessels, with no evidence of the tissue inflammatory response. Conversely, nodules containing degraded parasites were surrounded by an intense inflammatory infiltrate. The findings suggest that Didymodiclinus sp. have the potential to evade the host's immune system by inhibiting the inflammatory response.

Xenoligophoroides cobitis (Ergens, 1963) n. g., n. comb. (Monogenea: Ancyrocephalidae), a parasite of Gobius cobitis Pallas (Perciformes: Gobiidae) from the Mediterranean and Black seas

Based on an integrative taxonomic approach, combining morphological characters and partial sequences of the nuclear 28S rRNA gene, a new genus and combination for the species Xenoligophoroides cobitis (Ergens, 1963) is proposed, to accommodate ancyrocephalid monogeneans, parasites on the gills of Gobius cobitis Pallas (Gobiidae) from the western Mediterranean Sea and the northern Black Sea. A morphological comparison of newly collected material with the descriptions of Ancyrocephalus cobitis Ergens, 1963 and Haliotrema cupensis Sasal, Pages & Euzet, 1998, recently synonymised and named as Haliotrema cobitis (Ergens, 1963), confirms their similarity and belonging to the same species. However, characters of this species, as the vas deferens not looping the caecal branch, the bilobed base of the male copulatory organ and the marginal hooks with an upright thumb, do not correspond to the diagnosis of Haliotrema Johnston & Tiegs, 1922. Morphologically, this species is close to members of Ligophorus Euzet & Suriano, 1977 and Kriboetrema Sarabeev, Rubtsova, Yang & Balbuena, 2013, but differs from the former in the accessory piece articulated with MCO and two prostatic reservoirs, and from the latter in the uncoiled MCO with bilobed base and the dextral vaginal pore. Moreover, all species of Ligophorus and Kriboetrema are parasites of grey mullets. A 28S rDNA-based phylogenetic analysis of sequences derived from specimens of X. cobitis from the Mediterranean and Black seas, along with sequences from several closely related genera of the Ancyrocephalidae, suggested the occurrence of a new taxonomic unit, which corresponded to the X. cobitis specimens. This finding supports the establishment of the new genus for the ancyrocephalid parasites on the gills of G. cobitis from the western Mediterranean Sea and the northern Black Sea.

Intestinal granular cells of a cartilaginous fish, thornback ray Raja clavata: Morphological characterization and expression of different molecules

This investigation aims to fill gaps in our understanding of the intestinal immune cells of elasmobranchs. Whole digestive tracts of fifteen thornback ray Raja clavata were provided by a trawl fleet from the Gulf of Asinara (Sardinia, western Mediterranean Sea). Histochemical, immunohistochemical and ultrastructural observations were conducted on the spiral intestine. Three types of granular cells were identified; type I in epithelium, types II and III in lamina propria-submucosa, with each of them containing cytoplasmic granules with different ultrastructural characteristics. Data on size and density of each granular cell type are provided. Immunostaining of intestinal sections showed the reactivity of the granular cells: type I cells were positive for lysozyme, mast cell tryptase and tumor necrosis factor-ɑ based on antibody staining; type III cells were immune-reactive to anti-interleukin 6 antibody, whilst type II cells were negative to all the antibodies used. Comparison of each granular cell type with immune cells of teleosts or mammals and an hypothesis on their nature and function are reported. A potential role for granular cells in intestinal cellular immunity is also discussed with respect to type I and type III cells having similarities to Paneth cells and neutrophils, respectively.

Occurrence of Nematodes of the Genus Anisakis in Mediterranean and Atlantic Fish Marketed in Sardinia

Anisakiasis is a gastrointestinal fish-borne zoonosis caused by the ingestion of third stage larvae of the genus Anisakis. Between January and December 2013, 1112 specimens of four commercial fish species (Engraulis encrasicolus, Merluccius merluccius, Scomber colias and Trachurus mediterraneus) marketed in Sardinia (Italy) were examined for Anisakis sp. The overall prevalence of Anisakis spp larvae was 39.9%, all morphologically identified as Type I. Scomber colias showed the highest prevalence (100%), followed by M. merluccius (Atlantic 91.0%, Mediterranean 71.2%), T. mediterraneus (32.7%) and E. encrasicolus (25.9%). All the larvae found in Mediterranean hosts were genetically identified as Anisakis pegreffii, whereas 90.0% of the larvae found in the Atlantic M. merluccius belonged to Anisakis simplex sensu stricto and 10.0% to A. pegreffii. The mean abundance of Anisakis sp. larvae was positively correlated with fish size in E. encrasicolus, Atlantic M. merluccius and local M. merluccius. The prevalence of infection was greater in the body cavity (37.9%) than in the edible muscle (9.4%). However, 1.8% of the examined fish were infected exclusively in the muscle. Therefore, the risk associated to the consumption of raw or undercooked fishery products poses the need of measures such as visual inspection and preventive treatments to guarantee consumers' health.

Epidemiological and molecular data on heterophyid trematode metacercariae found in the muscle of grey mullets (Osteichthyes: Mugilidae) from Sardinia (western Mediterranean Sea)

This study is a contribution to the molecular taxonomy and epidemiology of heterophyid (Trematoda: Heterophyidae) metacercariae found in the muscle of Mugilidae (Osteichthyes) from Sardinia (western Mediterranean Sea). Sixty specimens of mugilids (13 Chelon labrosus, 18 Liza aurata, 6 Liza ramada, 8 Liza saliens, 15 Mugil cephalus) were examined and 17,899 metacercariae isolated in 95 % of the hosts. Four types of metacercariae were identified: Heterophyes sp. (n = 14,113), Heterophyes sp. -small (1225), Stictodora sp. (1606), and Ascocotyle (Phagicola) sp. (955). The experimental infection of a hamster with Heterophyes sp. metacercariae produced six adults identified as Heterophyes heterophyes and two as Heterophyes cf. nocens. The morphology of Heterophyes sp. -small metacercariae matched with that of Heterophyes dispar. The sequence analysis of the ITS2 and 28S portions of rDNA confirmed the morphological identification of metacercariae, showing four clusters. All adults grouped together with the Heterophyes sp. metacercariae, whereas adults of Heterophyes nocens from Korea clustered separately, showing that this species is distinguished from H. heterophyes, and suggesting caution in the exclusive use of the number of rodlets of the genital sucker to separate the two species. The presence of metacercariae was high in all hosts; the highest prevalence is of Heterophyes sp. (prevalence ≥78 %; mean intensity ≥135 metacercariae/100 g muscle), and the most heavily infected host is M. cephalus (prevalence = 100 %; mean intensity = 841 metacercariae/100 g muscle).

The first record of Gyrodactylus corleonis Paladini, Cable, Fioravanti, Faria & Shinn, 2010 (Monogenea: Gyrodactylidae) from the wild

Specimens of Gyrodactylus corleonis Paladini, Cable, Fioravanti, Faria & Shinn, 2010 (Monogenea: Gyrodactylidae) were collected from the body and fins of Gobius cobitis Pallas in the western Mediterranean Sea off northwestern Sardinia. This is the first finding of this species in the wild and also represents a new host record. A morphological comparison of the new material with the type description of G. corleonis is presented. Since G. corleonis was found in the wild on representatives of the Gobiidae, a comparison with species of Gyrodactylus von Nordmann, 1832 parasitising gobies is included. The occurrence of G. corleonis on different host species and its phylogenetic relationships with gyrodactylids from sand gobies are discussed.

Metazoan gill parasites of the Atlantic bluefin tuna Thunnus thynnus (Linnaeus) (Osteichthyes: Scombridae) from the Mediterranean and their possible use as biological tags

The gills of 63 specimens of the Atlantic bluefin tuna Thunnus thynnus (Linnaeus) (Osteichthyes: Scombridae) from three localities of the Mediterranean (Sardinian, Tyrrhenian and Levantine Seas) were examined for metazoan parasites. The parasite fauna of T. thynnus from the Sea of Sardinia included 11 species: five didymozoid trematodes, three capsalid and one hexostomid monogeneans, and one caligid and one pseudocycnid copepods. Four didymozoids were found in fish from the Levantine Sea and only one didymozoid was recorded in fish from the Tyrrhenian Sea. Dividing the hosts into four size-groups (small, medium-sized, large and extra large), the pairwise comparison of prevalence and mean abundance of the new and literary data) showed differences according to host size. The differences in the composition of the parasitic faunas and in the prevalence of parasites, observed between the small tunas from the Tyrrhenian Sea and the medium-sized tunas from the Adriatic Sea, Levantine Sea and the North-East (NE) Atlantic Ocean, indicated that these groups form discrete units. The parasite fauna of the large tunas from the Sea of Sardinia is the richest among the bluefin tuna populations of the Mediterranean and the NE Atlantic, due to the presence of species not found elsewhere in bluefin tunas, such as Caligus coryphaenae Steenstrup et Lütken, 1861, Capsala magronum (Ishii, 1936) and C. paucispinosa (Mamaev, 1968). This fact and the prevalence of some parasites of this group (lower than those of medium-sized fish from the NE Atlantic and higher than the small and medium-sized tunas from the Mediterranean) suggest that the large-sized tuna group in the western Mediterranean is formed by Mediterranean resident tunas (poorly infected), and by tunas migrating from the Atlantic Ocean (heavily infected).

Molecular and epidemiological data on Anisakis spp. (Nematoda: Anisakidae) in commercial fish caught off northern Sardinia (western Mediterranean Sea)

Anisakiasis is a fish-borne zoonosis caused by third stage larvae of the nematode Anisakis sp. present in fish or cephalopods. This is the first contribution to the molecular identification and epidemiology of Anisakis spp. in commercial fish from the Gulf of Asinara (Sardinia, western Mediterranean Sea). Between April 2006 to November 2011, 777 specimens of 10 fish species (Engraulis encrasicolus, Merluccius merluccius, Micromesistius poutassou, Phycis blennoides, Sardina pilchardus, Sardinella aurita, Scomber colias, Sphyraena viridensis, Trachurus mediterraneus, Trachurus trachurus) were examined for Anisakis sp. larvae. A total of 1286 larvae were found in 218 fish. The great majority of larvae were located in the body cavity, and only a small part (60, 4.7%) in the muscle. All the Type I larvae (1272) were identified as Anisakis pegreffii and all the Type II (14) as Anisakis physeteris, confirming that A. pegreffii is the dominant species and the most important agent of human anisakiasis in the western Mediterranean Sea.

Metazoan parasites on the gills of the skipjack tuna Katsuwonus pelamis (Osteichthyes: Scombridae) from the Alboran Sea (western Mediterranean Sea)

The gills of 31 skipjack tuna Katsuwonus pelamis (L.) caught in the Alboran Sea (western Mediterranean Sea) were examined for metazoan parasites, and the gills of 4 specimens from the Balearic Sea (also western Mediterranean Sea) were analysed for comparative purposes. Nine -species of parasites were found, including 8 didymozoid trematodes (Atalostrophion cf. bio-varium, Didymocylindrus filiformis, Didymocylindrus simplex, Didymocystis reniformis, Didymoproblema fusiforme, Didymozoon longicolle, Koellikeria sp. and Lobatozoum multisacculatum) and 1 caligid copepod (Caligus bonito). Koellikeria sp. and L. multisacculatum were not recorded in the Balearic Sea. Most of the parasites (79.2% of all specimens) were didymozoids. Didymozoon longicolle was the dominant species; A. cf. biovarium, D. simplex, D. fusiforme and L. multisacculatum are reported from the Mediterranean Sea for the first time. No correlation was found between the intensity of infection of any parasite species and host size or sex. Most of the parasites, particularly didymozoids, showed a high site-specificity. Significant differences were found between the parasite assemblages of K. pelamis from the Alboran Sea and from the Atlantic Ocean. D. fusiforme, D. longicolle and L. multisacculatum are suggested as potential tags to follow skipjack tuna migrations between the Atlantic Ocean and Mediterranean Sea.

Prevalence of Anisakis spp. and Hysterothylacium spp. larvae in teleosts and cephalopods sampled from waters off Sardinia

A study was carried out on the presence of Anisakis and Hysterothylacium larvae in fish and cephalopods caught in Sardinian waters. A total of 369 specimens of 24 different species of teleosts and 5 species of cephalopods were collected from different fishing areas of Sardinia. Larvae were detected and isolated by both visual inspection and enzymatic digestion. These methods allowed Anisakis type I and type II third-stage larvae and Hysterothylacium third- and fourth-stage larvae to be detected. The prevalence, mean intensity, and mean abundance were calculated. The results obtained showed the highest prevalence of Anisakidae in Zeus faber (100%) and of Anisakis in Micromesistius poutassou (87.5%). The highest prevalence of Anisakis type I larvae was in M. poutassou (81.2%), and that of Anisakis type II larvae was in Todarodes sagittatus (20%). The highest values for prevalence, mean intensity, and mean abundance for Hysterothylacium were found in Z. faber. These prevalences and the mean intensity and abundance were higher than those reported by different authors in other Mediterranean areas. This may be because the enzymatic digestive method used in this research resulted in higher recovery levels. The data suggest that Sardinia may be a high-risk area for zoonotic diseases and that measures such as information campaigns, aimed at both sanitary service personnel and consumers, should be employed to limit the spread of such zoonosis.

Molecular characterization of Hysterothylacium aduncum (Nematoda: Raphidascaridae) from different fish caught off the Tunisian coast based on nuclear ribosomal DNA sequences

Larval forms of the genus Hysterothylacium have been previously reported in teleost fish from the North African coasts of central Mediterranean Sea by morphological analysis. In the present study, samples identified morphologically as Hysterothylacium aduncum (n = 62), from Merluccius merluccius, Trachurus mediterraneus and Pagellus erythrinus from different geographical locations of the Tunisian coasts, were genetically characterised by sequences of the first (ITS-1), the 5.8S and second (ITS-2) Internal Transcribed Spacers (ITS) of nuclear ribosomal DNA (rDNA). Comparison of the sequences obtained with those available in public gene databases confirmed that all the samples from the Tunisian coasts belong to a single species, namely H. aduncum. All specimens from the Tunisian coasts showed one indel in position 787 in ITS-2 sequences not reported by any of the previously published sequences from the Atlantic and Pacific Oceans, Adriatic Sea (Mediterranean Sea) and the East Greenland Sea, suggesting the existence of a population-specific pattern exhibiting a low differentiation of this parasite in this area. This is the first molecular characterization of H. aduncum from the Tunisian coasts using ITS rDNA sequences which allows the definition of genetic markers for their unequivocal identification, and provides further biological data on these nematodes in marine fish off the Tunisian coasts, improving the picture of the occurrence of these taxa in the North African coasts of central Mediterranean Sea.

Molecular characterization of Fasciola spp. from the endemic area of northern Iran based on nuclear ribosomal DNA sequences

Fasciolosis caused by Fasciola spp. (Platyhelminthes: Trematoda: Digenea) is considered as the most important helminth infection of ruminants in tropical countries, causing considerable socioeconomic problems. In the endemic regions of the North of Iran, Fasciola hepatica and Fasciola gigantica have been previously characterized on the basis of morphometric differences, but the use of molecular markers is necessary to distinguish exactly between species and intermediate forms. Samples from buffaloes and goats from different localities of northern Iran were identified morphologically and then genetically characterized by sequences of the first (ITS-1) and second (ITS-2) Internal Transcribed Spacers (ITS) of nuclear ribosomal DNA (rDNA). Comparison of the ITS of the northern Iranian samples with sequences of Fasciola spp. from GenBank showed that the examined specimens had sequences identical to those of the most frequent haplotypes of F. hepatica (n=25, 48.1%) and F. gigantica (n=20, 38.45%), which differed from each other in different variable nucleotide positions of ITS region sequences, and their intermediate forms (n=7, 13.45%), which had nucleotides overlapped between the two Fasciola species in all the positions. The ITS sequences from populations of Fasciola isolates in buffaloes and goats had experienced introgression/hybridization as previously reported in isolates from other ruminants and humans. Based on ITS-1 and ITS-2 sequences, flukes are scattered in pure F. hepatica, F. gigantica and intermediate Fasciola clades, revealing that multiple genotypes of Fasciola are able to infect goats and buffaloes in North of Iran. Furthermore, the phylogenetic trees based upon the ITS-1 and ITS-2 sequences showed a close relationship of the Iranian samples with isolates of F. hepatica and F. gigantica from different localities of Africa and Asia. In the present study, the intergenic transcribed spacers ITS-1 and ITS-2 showed to be reliable approaches for the genetic differentiation of Fasciola spp., providing bases for further studies on F. hepatica, F. gigantica and their intermediate forms in the endemic areas in Asia.

Males of Ichthyofilaria argentinensis Incorvaia, 1999 and I. bergensis (Wülker, 1930) (Dracunculoidea:Guyanemidae): new morphological aspects and emendation of the generic diagnosis

Abstract: The adult male of dracunculoid nematode Ichthyofilaria argentinensis Incorvaia, 1999 (Guyanemidae) is described for the first time based on specimens found in the swimbladder of its type host, Merluccius hubbsi Marini (Merlucciidae), caught off the coast of Buenos Aires, Argentina (western Atlantic Ocean). In addition, the males of Ichthyofilaria bergensis (Wülker, 1930) Køie, 1993 are redescribed from specimens collected from the body cavity and visceral surface of Molva macrophthalma (Rafinesque) (Lotidae) caught in the western Mediterranean Sea, off the coast of Sardinia. Light and scanning electron microscopy examinations revealed some new morphological features for the genus, such as a pair of deirids located near the end of muscular oesophagus, the body wall conspicuously twisted immediately anterior to the cloaca, the presence of a copulatory plate, one pair of adcloacal papillae and a pair of phasmids situated on the posterior half of the tail. On the basis of this material, the generic diagnosis of Ichthyofilaria is modified to include some of these newly observed features, as well as to indicate the absence of spicules. The diagnosis of Guyanemidae is extended to include that a copulatory plate and/or two spicules may be present as characteristics for this family.

Outbreak of Sciaenacotyle panceri (Monogenea) on cage-reared meagre Argyrosomus regius (Osteichthyes) from the western Mediterranean Sea

Two different batches of meagre Argyrosomus regius were stocked in the same floating cage located in north-eastern Sardinia (western Mediterranean Sea). After 4 mo, the fish started showing non-specific disease signs, such as lethargy, emaciation, gill anaemia and mortality. In total 65 specimens of meagre of both stocks were sampled for parasitological and microbiological analysis, and only 1 species of parasite, the microcotylid monogenean Sciaenacotyle panceri, was found on the gills of caged meagre. No protozoan or other metazoan parasites were found and no bacteria or viruses were isolated. After the outbreak, a total mortality rate of 5 to 10% was estimated for the older fish stock, while no noteworthy mortality was recorded in younger fish (<2%). This is the first account of S. panceri on the gills of cultured meagre as causative agent of disease and mortality. The effects of the presence of this parasite emphasise the need for disease control strategies of cultured meagre, and investigating the transfer of microcotylids from wild to caged fish.

Redescriptions of Ligophorus cephali Rubtsova, Balbuena, Sarabeev, Blasco-Costa & Euzet, 2006 and L. chabaudi Euzet & Suriano, 1977 (Monogenea: Ancyrocephalidae), with notes on the functional morphology of the copulatory organ

Redescriptions of Ligophorus cephali Rubtsova, Balbuena, Sarabeev, Blasco-Costa & Euzet, 2006 and L. chabaudi Euzet & Suriano, 1977 based on original material from the Black Sea, the Mediterranean Sea and the Sea of Japan are presented. A comparison of samples of these two species from different regions was carried out with the aid of principal components analysis. The occurrence of L. chabaudi on Mugil cephalus in the Sea of Japan was confirmed. The functional morphology of the male copulatory organ was examined, and the use of the shape of this structure in the taxonomy of Ligophorus Euzet & Suriano, 1977 is discussed.

Molecular evidence for the occurrence of Contracaecum rudolphii A (Nematoda: Anisakidae) in shag Phalacrocorax aristotelis (Linnaeus) (Aves: Phalacrocoracidae) from Sardinia (western Mediterranean Sea)

Specimens of Contracaecum rudolphii Hartwich, 1964 (Nematoda: Anisakidae) from Phalacrocorax aristotelis (Linnaeus) from the Archipelago of La Maddalena (Sardinia, western Mediterranean Sea) were characterised genetically and compared with C. rudolphii A sensu D'Amelio et al. 1990 and C. rudolphii B sensu D'Amelio et al. 1990 from Phalacrocorax carbo sinensis (Blumenbach) from north-eastern Italy, and with C. rudolphii C sensu D'Amelio et al. 2007 from Phalacrocorax auritus (Lesson) from west-central Florida, USA. The sequencing of the small subunit of the mitochondrial ribosomal RNA gene (rrnS) and by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) analysis of the same gene and of the internal transcribed spacers (ITS) of nuclear ribosomal DNA (rDNA) allowed the identification of all specimens of C. rudolphii from P. aristotelis as C. rudolphii A. The results confirmed that the definition of genetic markers, following the analysis of nuclear ribosomal and mitochondrial DNA, provides quick and practical diagnostic tools for the detection of the 3 sibling species of C. rudolphii. The occurrence of C. rudolphii in P. aristotelis is reported for the first time from the Mediterranean area, improving the picture of the dispersal patterns of the populations of these piscivorous birds, and confirming the existence of different and isolated populations between the North and South European waters.

Reinstatement of Philometra jordanoi (López-Neyra, 1951) (Nematoda:Philometridae): a parasite of the Mediterranean dusky grouper Epinephelus marginatus (Lowe) (Osteichthyes, Serranidae)

Morphological examination of a single male philometrid nematode, recovered from the ovary of a dusky grouper Epinephelus marginatus caught off the north-east Mallorca (western Mediterranean), revealed morphological differences between this specimen and philometrid males from the gonads of other marine fish hosts. These differences, together with discrepancies between the descriptions of philometrid females found in the gonads of Mediterranean E. marginatus and those described to date in various hosts and/or seas, lead us to propose that Philometra jordanoi (López-Neyra, 1951) should be reinstated as a species parasitic in the gonads of the Mediterranean dusky grouper. The male of P. jordanoi is described for the first time.

Occurrence of Philometra lateolabracis (Nematoda: Philometridae) in the gonads of marine perciform fishes in the Mediterranean region

Gravid females of the nematode Philometra lateolabracis (Yamaguti, 1935), a parasite of gonads of marine perciform fishes, were found in wild and cultured dusky grouper Epinephelus marginatus (Lowe) from waters near the Balear Islands (Spain, Mediterranean Sea) and Sicily (Italy, Thyrrenean Sea), and in the greater amberjack Seriola dumerili (Risso) in Croatia (south-eastern Adriatic Sea). In wild E. marginatus in Spain, the overall prevalence was 21% and the intensity of infection 1 nematode per fish. The nematodes are briefly described and illustrated. The species Sanguinofilaria jordanoi López-Neyra, 1951, described from the ovary of Epinephelus gigas Brünich from Morocco, is synonymized with P. lateolabracis. This is the first documented record of P. lateolabracis from fishes of the Mediterranean region and its finding in S. dumerili represents a new host record. The possible importance of this pathogenic parasite for cultures of marine perciform fishes in the region is stressed.