Biology subjects

Aceto, S.

Publications and source records attributed to Aceto, S..

5 recordsLinked to original sources

bioRxiv2025

First report of Photobacterium damselae subspecies damselae in Razorbill (Alca torda)

A razorbill (Alca torda) was found dead in Bacoli, Italy, on January 16, 2023, during an exceptional irruptive event. The bird, a young female weighing 800 g with a moderate nutritional status and no external traumatic injuries underwent a post-mortem examination, which revealed coelomitis with severe congestion of the liver, lungs, kidneys, and myocardium. Lung, liver, kidney, and heart samples were collected for microbiological and histopathological analyses. Bacterial isolation on blood agar showed the growth of spherical/ovoid colonies after 48 hours, consistent with the Photobacterium genus. Identification by MALDI-TOF MS and PCR confirmed the presence of Photobacterium damselae subsp. damselae (Pdd), supported by 16S gene sequencing and detection of the ureC gene. PCR screening for virulence factors identified the hlyAch gene in lung samples, suggesting a potentially pathogenic strain in avian species. Histopathological examination showed severe, inflammatory infiltrates and widespread hemorrhages in the liver, the lung tissue and kidneys. In the myocardium, mild and multifocal lymphocytic infiltrates were present. These findings suggest a significant role of P. damselae subsp. damselae in the observed lesions. The results of the study revealed a new cross-species transmission of this potential zoonotic bacterium and the need for further research in this field. ImportanceWith this study we revealed the first isolation of Photobacterium damselae subsp. damselae in a razorbill but especially the first in a migratory bird. We documented a new cross-species transmission of P. damselae subsp. damselae and the need for further research, highlighting its zoonotic potential and therefore raising concerns about potential implications for marine wildlife, aquaculture and human health. Considering the role of migratory birds in the spread of infectious diseases even over long distances and the effect of climate change on marine ecosystems, and consequently on the circulation of pathogens, it is essential to adopt a preventive approach to mitigate this potential zoonotic risks.

microbiology↗

bioRxiv2024

Simultaneous silencing of gut nucleases and a vital target gene by adult dsRNA feeding enhances RNAi efficiency and mortality in Ceratitis capitata adults.

Ceratitis capitata, known as Mediterranean fruit fly (Medfly), is a major dipteran pest significantly impacting fruit and vegetable farming. Currently, its control heavily relies mainly on chemical insecticides, which pose health risks and have effects on pollinators. A friendly and species-specific alternative strategy involves providing double-stranded RNA (dsRNA) through feeding to disrupt essential functions in pest insects, which is poorly explored in dipteran species. Previous reports in Orthoptera and Coleoptera species suggested that dsRNA degradation by two specific nucleases in the intestinal lumen is among the major obstacle to feeding-mediated RNAi in insects. In our study, we experimented with three-day adult feeding using a combination of dsRNA molecules that target the expression of the ATPase vital gene and two intestinal dsRNA nucleases. These dsRNA molecules were recently tested separately in two Tephritidae species, showing limited effectiveness [1,2]. In contrast, we observed 79% mortality over seven days, which was associated with a decrease in mRNA levels of the three targeted genes. As expected, we also observed a reduction in dsRNA degradation following RNAi against nucleases. This research illustrates the potential of utilizing molecules as pesticides to achieve mortality rates in Medfly adults by targeting crucial genes and intestinal nucleases. Furthermore, it underscores the importance of exploring RNAi-based approaches for pest management Simple SummaryThe control of insect pest species, mainly belonging to Orthoptera, Hemiptera, and Coleoptera species, can be based on novel emerging species-specific pesticides. These consist of dsRNA molecules delivered by feeding to insect larvae or adults, which suppress vital gene functions by RNA-RNA sequence complementarity and RNA interference. However, fewer studies of dsRNA feeding have been performed in dipteran pest insects. Two studies in Orthoptera and Coleoptera species have shown that suppressing intestinal enzymes degrading external dsRNA can improve insect mortality rates. Ceratitis capitata (Tephritidae), the Mediterranean fruit fly (Medfly), is a major dipteran pest significantly impacting fruit and vegetable farming. Currently, its control heavily relies mainly on chemical insecticides, which pose health risks and have effects on beneficial pollinators. Previous attempts to induce mortality by adult dsRNA-feeding in this and other Tephritidae species, such as Bactrocera tryoni and B. dorsalis, showed some effectiveness, but were often limited. We improved this method by simultaneously silencing two intestinal nucleases and a vital gene. We have found a mix of three dsRNAs able to induce much higher mortality (79%) within one week, following only three days of adult feeding.

genetics↗

bioRxiv2023

A WIDESPREAD PICORNAVIRUS AFFECTS THE HAEMOCYTES OF THE NOBLE PEN SHELL (PINNA NOBILIS) LEADING TO IMMUNOSUPPRESSION

The widespread mass mortality of the noble pen shell (Pinna nobilis) has occurred in several Mediterranean countries in the past seven years. Single-stranded RNA virus affecting immune cells and leading to immune disfunction have been widely reported in human and animal species. Here we present data linking P. nobilis mass mortality events (MMEs) to haemocyte picornavirus (PV) infection. This study was performed on 30 specimens, from wild and captive populations. We sampled P. nobilis from two regions of Spain, Catalonia [24 animals] and Murcia [two animals]), and one region in Italy (Venice [four animals]). The low number of analyzed specimens was due to the scarcity of remaining individuals in the Mediterranean Sea. In 100% of our samples, ultrastructure revealed the presence of a virus (20nm diameter), capable of replicating within granulocytes and hyalinocytes, leading to the accumulation of complex vesicles of different dimensions within the cytoplasm. As the PV infection progressed, dead haemocytes, infectious exosomes, and budding of extracellular vesicles were visible, along with endocytic vesicles entering other cells. The THC (total haemocyte count) values observed in both captive (eight animals) (3.5 x 104 - 1.60 x105 ml-1 cells) and wild animals (14 samples) (1.90 - 2.42 x105 ml-1 cells) were lower than those reported before MMEs. Sequencing of P. nobilis (six animals) haemocyte cDNA libraries revealed the presence of two main sequences of Picornavirales, family Marnaviridae. The highest number of reads belonged to animals that exhibited active replication phases and abundant viral particles from Trasmission Electron Microscopy (TEM) observations. These sequences correspond to the genus Sogarnavirus - a picornavirus identified in the marine diatom Chaetoceros tenuissimus (named C. tenuissimus RNA virus type II). Real time PCR performed on the two most abundant RNA viruses previously identified by in silico analysis revealed positive results only for the sequences similar to C. tenuissimus RNA virus. These results may not be considered conclusive of picornavirus identification in noble pen shell haemocytes, and require further studies. Our findings suggest that picornavirus infection likely causes immunosuppression, making individuals prone to opportunistic infections which is a potential cause for the MMEs observed in the Mediterranean.

pathology↗

bioRxiv2019

Diagnosis of Centrocestus formosanus Infection in Zebrafish (Danio rerio): A Window on a New Globalization-Derived Invasive Parasite.

Centrocestus formosanusis a digenetic trematode with a complex life cycle, involving invertebrate and vertebrate hosts, humans included. In particular, it causes gill lesions and mortality in freshwater fish species, and gastrointestinal symptoms in infected humans. Here,we describe the occurrence of C. formosanus infection in zebrafish imported in Italy. Gill arches of 30 zebrafish were examined for the presence of encysted metacercariae under a stereomicroscope, and processed through molecular analyses targeting the ribosomal Internal Transcribed Sequence 2 (ITS2) using species-specific primers of C. formosanus. Encysted metacercariae were found on the gills of 20/30 zebrafish and all were identified as C. formosanus.\n\nDespite C. formosanus distribution was originally restricted to Asia, it has been subsequently reported in new countries, revealing itself as an invasive species, and raising important concerns for biodiversity, economy, animal and public health. Given the crucial role likely played by the ornamental fish industry in the spreading of this parasite, there is an urgent need for control measures to prevent the introduction and establishment of C. formosanus in non-endemic areas, Europe included. An adequate surveillance and health-monitoring program should be conducted in the development of microbiological and epidemiological approaches to diagnose and face these new globalization-derived invasive species.

microbiology↗

bioRxiv2019

Genomics and transcriptomics to unravel sex determination pathway and its evolution in sand flies

BackgroundPhlebotomine sand flies (Diptera, Nematocera) are important vectors of several pathogens, including Leishmania parasites, causing serious diseases of humans and dogs. Despite their importance as disease vectors, most aspects of sand fly biology remain unknown including the molecular bases of their reproduction and sex determination, aspects also relevant for the development of novel vector control strategies.\n\nResultsUsing a comparative genomics/transcriptomics approach, we identified the sex determining genes in phlebotomine sand flies and proposed the first model for the sex determination cascade of these insects. For all the genes identified, we produced manually curated gene models, developmental gene expression profile and performed evolutionary molecular analysis. We identified and characterized, for the first time in a Nematocera species, the transformer (tra) homolog which exhibits both conserved and novel features. The analysis of the tra locus in sand flies and its expression pattern suggest that this gene is able to autoregulate its own splicing, as observed in the fruit fly Ceratitis capitata and several other insect species.\n\nConclusionsOur results permit to fill the gap about sex determination in sand flies, contribute to a better understanding of this developmental pathway in Nematocera and open the way for the identification of sex determining orthologs in other species of this important Diptera sub-order. Furthermore, the sex determination genes identified in our work also provide the opportunity of future biotech applications to control natural population of sand flies, reducing their impact on public health.

genomics↗