1,721,231 research outputs found
WINTER DISEASE IN ASSOCIATION WITH INTESTINAL NON-FORMING XENOMA MICROSPORIDIA IN GILTHEAD SEABREAM (SPARUS AURATA)
No full textAIM OF THE STUDY:
Winter disease (WD) is a multifactorial disease found primarily in sea caged gilthead sea bream (Sparus aurata) along the
Mediterranean coast.1,2 An emaciative syndrome has been recently observed in Spain and Enterospora nucleophila, a new
microsporidian species of the family Enterocytozoonidae has been described; these intracellular, non-forming xenoma
microsporidia, opportunistic in nature exploit a w eakened host immune status, as it could happen in WD.6 Teleost intestine
contains Mast Cells (MCs), w hose functional properties are similar to those of mammalian mast cells;5 recruitment of MCs to
sites of persistent inflammation is a general response in parasites-affected fish. An increased number of the MCs is also
reported in WD-affected fish.3,4 In December 2013 a disease outbreak in sea caged gilthead seabream in Italy, affecting 0+
year fish occurred. The aim of this study w as to evaluate the histopathological changes related to these tw o conditions, to
characterize the MCs by immunohistochemistry and the microsporidia by PCR.
MATERIAL AND METHODS:
From tw enty gilthead sea bream intestinal tracts w ere fixed in buffered formalin at the sample site and sent to DIMEVET.
Routine histological sections w ere obtained; Luna stain w as also performed. Immunohistochemistry w ith CD117 antibody
(1:100, Dako) w as also carried out. Intestinal tissue w as also subjected to molecular analysis; a fragment of the 18S rDNA
w as amplified and then sequenced.
RESULTS:
Hindgut show ed a moderate dilatation of the lumen in association w ith w hitish casts, similar to the milk-like mucous casts
reported in WD outbreaks.1,2 A severe mucosal atrophy w ith total folds flattening w as present; w ithin lamina propria and
submucosa a mild to moderate MCs hyperplasia and mild mucous cells hyperplasia w ere observed. Multifocally, w ithin
enterocytes and rodlet cells, the nucleus and/or cytoplasm contained microsporidian spores, more evident w ith Luna stain.
The sequences obtained from intestines show ed 99.9% identity w ith E. nucleophila. Within perivisceral exocrine pancreatic
acini, focal necrosis and MCs infiltration have been observed, as reported by other authors during WD outbreaks.
CONCLUSIONS:
MCs are interpreted as ‘‘standing force’’ in particular tissues consistently exposed to pathogens, in contrast to a ‘‘mobilization
force’’ that has been an advantage in those being exposed to noxious agents only occasionally.7 The severe mucosal
flattening could be interpreted as an effect of a chronic insult, not only related to the microsporidia infection; other
concurrent predisposing factors as those reported in WD could be then considered into the development of an overt
pathology.
BIBLIOGRAPHY:
1Birincioglu et al, 2013; 2Colorni, 2011; 3Contessi et al,2006; 4Ibarz et al, 2010; 5Lauriano et al.,2012;6 Palenzuela et
al.,2014; 7Reite and Evensen,2006
A 9000 YEARS LONG HISTORY OF TREMATODES PARASITISM IN BRACKISH SETTINGS OF ITALY
No full textThe rising global temperature and sea-level have led to concern about the increase of parasites at our latitudes. Ecological studies on parasitism is forcibly restricted to short-time intervals (months/years). The Holocene fossil record can offer a quantitative archive of ecological responses to geological short (102-103 yr) but societally relevant past climate transitions. This study investigates infestation frequency (prevalence) of trematode flatworms attributed to Gymnophallids through the last 9ky in modern and Holocene brackish settings. These parasites typically display a complex lifecycle with three hosts. It is usually in the second host that gymnophallids encyst in a latent stage of metacercaria and induce the active growth of oval pits on the interior of the shell. These pits are preserved in the fossil record, thus providing a proxy for past parasitic dynamics. We focused on the brackish bivalve Abra segmentum due to its abundance in Holocene brackish settings. A sampling campaign was performed in the lagoons of Piallassa Baiona, Saline di Cervia (Emilia Romagna) and Lesina (Apulia). As for Emilia Romagna sites, ~200 specimens have been collected from June to July 2017. In Lesina, ~100 specimens were collected in the winter of 2016 and ~200 specimens in the following summer. Each specimen was examined to detect the presence of sporocyst, cercariae and metacercariae of digenean trematodes. The soft tissues of infected clams have been preserved in ethanol 70% and photographed with a digital camera at different magnification (4x and 10x) for morphological and molecular identification. The shells of all bivalves (modern and fossil) were observed with a stereomicroscope to detect the presence of parasite traces. In modern brackish setting parasite prevalence, when restricted to samples with only metacercariae, shows a low spatial variability. The mean prevalence is comparable among Lesina and Saline di Cervia (21%±5%, and 20%±5%, respectively) and lower in Piallassa Baiona (7%±3%). At seasonal scale, Lesina samples collected in the winter show a reduced prevalence respect to the summer ones, attaining a maximum value of 6%. On the contrary, across Holocene brackish deposits single sample infestation, range from 6% to 70% and display a significant temporal variation along core (that is, outside the 95% confidence bound estimated via randomization). Significantly elevated infestations are recovered proximity to previously documented flooding surfaces. Whereas, non-significantly prevalence estimates (i.e., within 95% confidence bound) all occurred within the sedimentary units bounded by surfaces that testify past floods. In addition, measurements of the pits on the living bivalve shells are smaller and morphologically less pronounced (shallow) than the fossil counterparts. Finally, the average infestation (pits) in the brackish deposits during phases of rapid sea level rise (flooding surfaces), is significantly higher (~57% ± 4%) than the highest prevalence recorded in modern settings (~32% ± 4%). This result hints a possible association between significantly elevated prevalence and centennial scale flooding events and support the link between sea-level rise and increasing parasite activity. The recognition of the link between parasite prevalence and past sea-level rises provides us with an important reference framework for assessing near-future parasite related threats ignited by global warming
Risk mapping of zoonotic parasites in Italian aquaculture
No full textIntroduction: The diffusion of new eating habits and the increase of fish products demand lead to a raising risk for consumers inherent food-borne parasitic zoonoses. In this scenario the scientific community and food security authorities are called to assess the possible risks linked to consumption of products from fishery and aquaculture and to set up strategies aimed to their management. Thus, the collection of epidemiological information on the presence of zoonotic parasites in fish products through extensive epidemiological surveys is necessary. Concerning aquaculture, according to EFSA (2010) and Regulation (EU) 1276/2011 only for the Atlantic salmon the risk of transmission of parasites to man can be considered negligible. At this purpose, in the framework of the EU funded project ParaFishControl a wide parasitological survey has been carried out on the main farmed fish species in Italy and other countries such as Spain, Greece, Denmark, Norway and Hungary. The present work reports the results from Italy. Methodology: From 2016 to 2018 a total of 4728 farmed fish have been examined from 5 marine and 5 freshwater farms located in Italy: 1563 gilthead sea bream (GSB), 1571 European sea bass (ESB) and 1594 rainbow trout (RT) have been sampled. Besides harvest quality fish, runts were also examined. Parasitological analyses to search for anisakid nematodes, diphyllobothriid cestodes and Opisthorchioidea digeneans were performed utilizing different methodologies such as visual inspection and candling as provided by the EU regulation, implemented by UV-press
method, muscular compression/artificial digestion followed by microscopic examination when required.
Results: No zoonotic parasites were found in any of the examined fish, including runts. Only one L4 specimen of the nematode Hysterothylacium fabri has been found on the surface of the liver in one ESB. Conclusion: The results of this survey are very encouraging and allow to assess the risk of the presence of zoonotic parasites in farmed GSB, ESB and RT as negligible, similarly to Atlantic
salmon
Studi sulle infestazioni da stadi larvali di Trematodi Digenei in Palaemon spp. (Decapoda: Palaemonidae delle lagune del delta del Po / Studies on infestations by larval stages of digenean trematodes in Palaemon spp. from Po Delta lagoons.
No full textRIASSUNTO – I gamberetti di laguna del genere Palaemon rappresentano una risorsa tradizionale locale per
generazioni di pescatori e consumatori delle zone lagunari del Delta del Po e rivestono un importante ruolo negli
ecosistemi vallivi. Le informazioni scientifiche concernenti la loro parassitofauna sono però estremamente scarse
sia a livello nazionale che internazionale. Da tale mancanza di dati nasce il presente studio, che si è posto come
obiettivo principale quello di approfondire le conoscenze sulla parassitofauna delle specie Palaemon adspersus e
P. elegans, focalizzando le ricerche sulle infestazioni da stadi larvali di trematodi digenei Microphallidae in
questi gamberetti nella laguna di Comacchio (Emilia-Romagna, Italia). Tutti gli esemplari sono stati sottoposti ad
analisi parassitologiche quantitative e qualitative ed i parassiti digenei rinvenuti allo stadio di metacercaria sono
stati oggetto di analisi morfometriche volte alla loro identificazione. I risultati ottenuti hanno evidenziato
un’ampia diffusione di metacercarie di trematodi Microphallidae, peraltro con valori estremamente elevati di
prevalenza, nei gamberetti esaminati rilevando la spiccata idoneità di questi crostacei come ospiti intermedi pur
con importanti differenze dei valori d'intensità di infestazione in relazione alla taglia ed alla stagionalità. Sulla
base delle caratteristiche morfologiche è stato possibile riferire il parassita oggetto di studio alla specie
Maritrema oocysta (Microphallidae), che non risultava ad oggi essere mai stata descritta in Palaemon adspersus e
P. elegans.
SUMMARY - Lagoon shrimps of the genus Palaemon represent a traditional local resource for generations of
fishermen and consumers of the lagoon areas of the Po Delta and play an important role in the valley ecosystems.
However, scientific information concerning their parasitic fauna is extremely scarce both nationally and
internationally. From this lack of data comes the present study, which has had as its main objective to deepen the
knowledge on the parasitofauna of the species Palaemon adspersus and P. elegans, focusing research on the
infestations by larval stages of Microphallidae digenean trematodes in these shrimps in the Comacchio lagoon
(Emilia-Romagna, Italy). All the specimens were subjected to quantitative and qualitative parasitological
analyses and the digenean parasites recovered at the stage of metacercaria underwent morphometric studies
aimed at their identification. The results obtained showed a wide diffusion of Microphallidae trematode
metacercariae, moreover with extremely high prevalence values, in the examined shrimps, highlighting the
marked suitability of these crustaceans as intermediate hosts albeit with important differences in the infestation
intensity values in relation to the size and seasonality. On the basis of the morphological characteristics, it was
possible to refer the parasite under study to the species Maritrema oocysta (Microphallidae), which to date had
never been described in Palaemon adspersus and P. elegans
Differential diagnosis between Tunga penetrans (L, 1758) and T. trimamillata Pampiglione et al., 2002 (Insecta, Siphonaptera), the two species of the genus Tunga parasitic in man
No full textOf the ten currently known species of sand fleas, only two, Tunga penetrans and Tunga trimamillata, are known to be parasites of man, besides other warm blooded animals, most of which are peridomestic. The hosts of the other eight are limited to a few genera of wild mammals. T. trimamillata was only recently identified and differentiated from T. penetrans by features of the gravid female phase. In the present paper the different morphological characters of both for non-gravid females and males of the two species are described. In the non-gravid-females the distinguishing characters are : a) differences in the length of the first two segments of the maxillary palps (the first is the longest in T. trimamillata, whereas the second is the longest in T. penetrans), this feature is associated with another character i.e. the presence of short, thick spines in addition to the bristles on the surface of the segments only in T. trimamillata ; b) the presence, only in T. trimamillata, of a row of spines on the antero-medial surface of the tibia of the 3rd pair of legs ; c) the last abdominal spiracle protrudes in T. trimamillata but not in T. penetrans ; d) the hood of the hilla in spermatheca is surrounded by a papilla only in T. penetrans. The following morphological characters differentiate males of T. trimamillata and T. penetrans ; a) T. trimamillata has a row of spines on the antero-medial surface of the tibia of the 3rd pair of legs ; b) the diameter of the abdominal spiracles of T. trimamillata is smaller than that of T. penetrans and the edges of the spiracles are more regular ; c) the claspers and aedeagus of T. trimamillata are shorter than those of T. penetrans ; d) the profile of the aedeagal apodeme differs between the two species
Bothriocephalidean tapeworms (Cestoda) from the blackfish, Centrolophus niger (Perciformes: Centrolophidae)
No full textBothriocephalidean tapeworms parasitic in the blackfish, Centrolophus niger (Gmelin) (Perciformes: Centrolophidae),
are redescribed on the basis of the evaluation of freshly collected specimens and museum material. This evaluation enabled us to
supplement species diagnoses by new morphological characters of potential use for phylogenetic analyses, including the data
from scanning electron microscopical observations, and to provide a key to identification of the following four species occurring
in this fish: Amphicotyle heteropleura (Diesing, 1850); Milanella familiaris Kuchta et Scholz, 2008 (both Triaenophoridae); Bothriocotyle solinosomum Ariola, 1900; and Echinophallus wageneri (Monticelli, 1890) (both Echinophallidae). Large spini-
form microtriches were observed on the surface of the posterodorsal margin of segments of B. solinosomum, E. wageneri and M. familiaris. The invalidity of Atelemerus Guiart, 1935, first proposed by Bray et al. (1994), is supported by the present data and its type species, A. acanthodes Guiart, 1935, is newly synonymised with E. wageneri
Is the worm-like organism found in the statoblasts of Plumatella fungosa (Bryozoa, Phylactolaemata) the vermiform phase of Tetracapsuloides bryosalmonae (Myxozoa, Malacosporea)?
No full textTetracapsuloides bryosalmonae is a malacosporean parasite
causing Proliferative Kidney Disease (PKD) of salmonids, which
develops in a sac-shaped phase producing infective spores in
freshwater bryozoans. From 2001-2003, several samples of bryozoans
were collected along the Sile River (Treviso Province,
northern Italy) from sites which are in close communication with
two trout farms where PKD is enzootic. All the colonies found
were observed under a stereomicroscope in search of T.
bryosalmonae and to isolate statoblasts. The bryozoans were classified
by studying the superficial microarchitecture of the statoblasts
using a scanning electron microscope (SEM). The following
species were identified: Cristatella mucedo, Fredericella sultana,
Plumatella casmiana, P. emarginata, P. fungosa, P. repens, P.
reticulata, P. rugosa, and P. similirepens. Developmental stages of
T. bryosalmonae were never found in the colonies. In 11 out of
40 P. fungosa floatoblasts, treated with KOH for SEM study, vermiform
structures of 0.5-8 mm in length were observed. The possibility
that these structures could represent the vermiform phase
of T. bryosalmonae with a developmental stage similar to those
described for Buddenbrockia plumatellae is discussed
Dirofilarial human cases in the Old World, attributed to Dirofilaria immitis: A critical analysis
No full textAIMS: To review 28 cases of human dirofilariasis reported in the last 30 years in the Old World and attributed, by their respective authors, to Dirofilaria immitis or a species of Dirofilaria other than D. repens. METHODS AND RESULTS: Each case was analysed by examining the published accounts or by discussions with the authors, who were interviewed whenever possible. CONCLUSIONS: On the basis of these analyses we conclude that there is as yet no proof demonstrating with certainty that Old World D. immitis plays a pathogenic role in humans. It remains to be explained why D. immitis causes pulmonary infections in humans in the Americas while, in the Old World, this location appears, instead, to be always associated with D.repens, even though the former species is at times more frequent than the latter both in dogs and in the vectors. To explain this apparently different pathogenic power, two hypotheses are proposed: (i) there are perhaps twin populations with different genotypes on the two sides of the Atlantic, with different infective capacity for man and dog; (ii) the infective capacity to humans of the parasite could be modified, only in the Old World, by some unidentified factor, possibly inherent to the vector, that affects the complex mechanism of the vector-parasite relationship, affecting the survival of the larvae
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