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Listeria monocytogenes is a widespread Gram-positive pathogenic bacterium that causes listeriosis, a rather rare but severe foodborne disease. Pregnant women, infants, the elderly, and immunocompromised individuals are considered particularly at risk. L. monocytogenes can contaminate food and food-processing environments. In particular, ready-to-eat (RTE) products are the most common source associated with listeriosis. L. monocytogenes virulence factors include internalin A (InlA), a surface protein known to facilitate bacterial uptake by human intestinal epithelial cells that express the E-cadherin receptor. Previous studies have demonstrated that the presence of premature stop codon (PMSC) mutations naturally occurring in inlA lead to the production of a truncated protein correlated with attenuate virulence. In this study, 849 L. monocytogenes isolates, collected from food, food-processing plants, and clinical cases in Italy, were typed and analyzed for the presence of PMSCs in the inlA gene using Sanger sequencing or whole-genome sequencing (WGS). PMSC mutations were found in 27% of the isolates, predominantly in those belonging to hypovirulent clones (ST9 and ST121). The presence of inlA PMSC mutations in food and environmental isolates was higher than that in clinical isolates. The results reveal the distribution of the virulence potential of L. monocytogenes circulating in Italy and could help to improve risk assessment approaches.

Listeria monocytogenes (L. monocytogenes) is a widespread opportunistic pathogen that causes the listeriosis foodborne disease. This bacterium has become a common contaminant of handled food, and a relevant public health issue. Here we describe a nosocomial outbreak of listeriosis caused by an ST451 strain of L. monocytogenes involving three cancer and one immunocompromised patients hospitalized in different units from the same hospital during September and October 2020. The epidemiological investigation was conducted using traditional microbiological methodology combined with a whole genome sequencing approach. The source of contamination was identified in the kitchen hospital, where a meat slicer used to prepare patients’ meals was tested positive to the same sequence type (ST) of L. monocytogenes. This is the first report of an outbreak of listeriosis caused by ST451 in Italy.

A coiled shell is the most evident feature of the typical Bauplan of a gastropod mollusc. However, at least 54 families independently evolved an apparently simplified shell morphology: the limpet. Species with this largely uncoiled, depressed shell morphology occur in almost every aquatic habitat and are associated to a number of different lifestyles and diets. The marine gastropod family Capulidae includes 18 recognised genera, the large majority of which are coiled, but with a number of limpet-like species. Capulid shell plasticity is also associated to a broad range of feeding ecologies, from obligate suspension feeders to kleptoparasites. To investigate the evolution of the limpet-like shell in the family Capulidae we performed an ancestral state reconstruction analysis on a time-calibrated phylogenetic tree (COI, 16S, and ITS2) including 16 species representing a good deal of its morphological diversity. Our results identified at least three capulid lineages that independently evolved limpet-like shells, suggesting that a recurrent limpetization process characterizes this family. One of the limpet-like genera was undescribed and was here named Cryocapulus n. gen. We suggest that capulids evolved from a coiled suspension feeder lineage and that the shift to kleptoparasitism, which occurred in the family ancestor, may have represented a strategy to save energy through the exploitation of the water current produced by the host. Probably the major drivers of shell evolution in capulids are related to their ecology, most of them being kleptoparasites, include the shape and the kind of host substrate, and lead to the repeated acquisition of a limpet-like shape.

Giannuzzi-Savelli, Riccardo, Pusateri, Francesco, Prkić, Jakov, Bartolini, Stefano, Russini, Valeria, Fassio, Giulia, Oliverio, Marco (2020): Revision of Mediterranean and NE Atlantic Raphitomidae (Gastropoda, Conoidea) 8: The genus Leufroyia Monterosato, 1884. Zoosystema 42 (22): 433-473, DOI: 10.5252/zoosystema2020v42a22

The systematics of several Eastern Atlantic conoidean species, traditionally ascribed to the genus RaphitomaBellardi, 1847, are revised on the basis of DNA sequence data from three gene regions (cytochrome c oxidase subunit I, 16S rRNA and 12S rRNA). We assign genus ranking to three major lineages (Raphitoma, CyrilliaKobelt, 1905 and LeufroyiaMonterosato, 1884) and suggest that two West African species belong in the subgenus Daphnella (Paradaphne) Laseron, 1954. A new classification, based on molecular systematics and critical study of morphology, is provided for all Eastern Atlantic and Mediterranean species that are currently ascribed to Raphitoma s.l. The genus ClathromangeliaMonterosato, 1884 is confirmed as belonging to Raphitomidae. Phylogenetic relationships and genetic distances suggest that Raphitoma maculosaHøisæter, 2016 and R. obesaHøisæter, 2016 may be divergent morphotypes of R. bicolor (Risso, 1826) and Cyrillia aequalis (Jeffreys, 1867), respectively.

The recent report of Nemoura lacustris Pictet, 1865 in Great Britain has raised doubts on its identity, given the isolation with respect to the Mediterranean and continental populations of this species. Using molecular analyses, we tested if populations from the United Kingdom and the Iberian Peninsula were conspecific and tested the hypotheses of a recent colonization event versus a more ancient origin for the British populations. Phylogenetic analysis of the mitochondrial marker COI allowed us to conclude that the United Kingdom specimens morphologically ascribed to N. lacustris were conspecific with populations from France and the Iberian Peninsula. Based on the genetic divergence of the two reciprocally monophyletic clades from the Iberian Peninsula and Great Britain/France, respectively, the present distribution of N. lacustris can be postulated as a relatively recent dispersal or introduction into Great Britain from France. Finally, we note the isolated position displayed by N. lacustris in the phylogenetic tree of Nemoura species based on COI sequences, as the sister to all included species of the genus. This isolated position corresponds with the specific morphology of N. lacustris genitalia and requires additional studies to ascertain clearer generic boundaries within the Nemouridae.

The thermophilic Aphaenogaster testaceopilosa-group is a taxon consisting of 14 species in Europe. Recently, this group was recently revisited using morphological characters suggesting different changes in the systematic of this group. For the first time, in this work we used a molecular approach using the DNA barcoding on the european members of the genus Aphaenogaster in order to: i) validate the current systematic of the A. testaceopilosa group in Italy, ii) test the efficiency of COI marker to delimit the species belonging to the genus Aphaenogaster. In the first phase, we morphologically identified 54 specimens of A. testaceopilosa group collected along the entire Italian range. In the second phase, fragments of COI and CAD markers were sequenced from phenotyped individuals. Phylogenetic reconstructions and genetic distances clearly showed six lineages (MOTUs) in agreement with morphological identification except for one specimen collected in a likely contact zone between Aphaenogaster picena and Aphaenogaster semipolita. Furthermore, this study confirms the powerful of DNA barcoding to support the morphological analysis to delimit the species belonging to Aphaenogaster testaceopilosa-group. Therefore, genetic data could be a valid tool to investigate other more problematics groups of this little-known genus.