On the occurrence of Crocidura Suaveolens Pallas (Mammalia, Insectivra) in the Maltese Islands with notes on other Maltese shrews

Crocidura suaveolens Pallas, 1811 is recorded definitely for the first time from the Maltese Islands. Previous records of this species are reviewed and are shown to refer to other species or else to be unconfirmed. Besides C. suaveolens, two other shrews inhabit the Maltese Islands. Sunclts e"ruscus (Savi) is distributed in both Malta and Gozo while both C. suaveolens Pallas and C. russula (Hermann) appear to be restricted to the island of Gozo. The latter species has not, however, been recorded in this study.peer-reviewe

A note concerning the scorpions (Arachnida : Scorpiones) of the Maltese Islands (Central Mediterranean)

All scorpions collected from the islands of Malta, Gozo, Camino and St. Paul's belonged to Euscorpius (s.str.) carpathicus (linnaeus, 1773) ssp. candiota Birula, 1903 as used by Kinzelbach (1975) for populations showing a complex of morphological characters intermediate between E.carpathicus carpathicus and E.mesotrichus Hadzi. Similar intermediate populations are found in several eastern Mediterranean localities (Greece, some Greek islands and Crete)" however the Maltese populations are more heterogenous than any other so far studied. The literature contains records of other species of scorpion from the Maltese Islands whereas the collections of the British Museum (Natural History), London include specimens of Mesobuthus gibbosus (Brulle) reportedly collected from Malta. These records are discussed and it is postulated that they are either errors of identification or labelling, or else represent introduced exotics now locally extinct.peer-reviewe

On the occurrence of Agama agama (L.) (Reptilia : Agamidae) in the Maltese Islands

A live female specimen of Agama agama (L.) was found amongst crates of imported beer at Marsa, Malta in October 1979. This lizard was probably transported to Malta from North Africa with cargo.peer-reviewe

Notes concerning the semi-terrestrial and freshwater amphipods (Crustacea : Peracarida) of the Maltese Islands

Interest in Mediterranean amphipods has been re-focused recently by the appearance of a new multi-author monograph on the group edited by Professor Sandro Ruffo (1982 and continuing) which, when complete, will replace the classic work of Chevreux & Fage (1925). In spite of this progress, however, wide areas of the Mediterranean are still almost unknown amphipodologically (Ruffo (ed.), 1982) and detailed fauna lists are wanting for many regions. For the past few years, one of us (P.I.S.) has been surveying bodies of freshwater in the Maltese Islands and samples have now been amassed from all the main fresh- and brackish water sites in the islands. Since just about every body of freshwater dries up early in the summer (and remains so for the best part of six months each year) it is interesting to see just how many amphipod species the islands' freshwaters support. Since present knowledge of Maltese semi-terrestrial amphipods is also limited they too have been included in our surveys. The following list summarizes our taxonomic (P.G.M.) and ecological (P.I.S.) knowledge of the Amphipoda from these habitats on the Maltese Islands. All material is deposited in the personal collections of P.I.S. with the exception of Allorchestes aquilinus (A. Costa) which is in the collections of P.G.M.peer-reviewe

Occurrence of Paraleucilla magna Klautau et al., 2004 (porifera : Calcarea) in Malta

The calcareous sponge Paraleucilla magna, first recorded from the Mediterranean in 2001 (southern Tyrrhenian, southern Adriatic and northwest Ionian coasts of Italy), is recorded from Malta (Central Mediterranean) where it was found forming part of the fouling community on small, surface marker-buoys around a fish-farm in Marsaxlokk Bay.peer-reviewe

New records of the genus Pachygrapsus (Crustacea : Decapoda) from the central Mediterranean Sea with a review of its Mediterranean zoogeography

The occurrence of Pachygrapsus maurus and Pachygrapsus transversus is reported from the Maltese Islands for the first time on the basis of one specimen of P. maurus collected in 1990 and numerous recent specimens, and the distribution of the two species is mapped. The controversial presence of P. maurus in Italy is confirmed and two new sites for this species are reported, including the first for the mainland of Italy. The examination of the historical specimen of P. maurus from the Genova area revealed a misidentification of P. transversus; this record could be a result of ship-mediated transport. First notes on the habitat of P. maurus in the central Mediterranean Sea are given. Updated maps of the distribution of P. maurus and P. transversus in the Mediterranean are provided and the zoogeography of these species is revisited.peer-reviewe

Macrofaunal diversity of infralittoral cobble beds in the Maltese Islands

This research work was partially funded through the European Social Fund under a STEPS scheme grant awarded to JE.The Mediterranean “biocoenosis of infralittoral pebbles ” has been poorly studied, but is generally considered to be impoverished. Systematic sampling of cobble beds at 17 sites around the Maltese Islands yielded a total of 35,687 individuals belonging to 310 different taxa. Very shallow sites (<2 m depth) had a slightly poorer faunal assemblage than deeper ones (2 -12 m depth), but still included 152 taxa. These results suggest that infralittoral cobbles beds may not be as impoverished as previously thought, probably due to the high structural complexity of these habitats.peer-reviewe

Molecular characterization of the EhaG and UpaG trimeric autotransporter proteins from pathogenic Escherichia coli

Trimeric autotransporter proteins (TAAs) are important virulence factors of many Gram-negative bacterial pathogens. A common feature of most TAAs is the ability to mediate adherence to eukaryotic cells or extracellular matrix (ECM) proteins via a cell surface-exposed passenger domain. Here we describe the characterization of EhaG, a TAA identified from enterohemorrhagic Escherichia coli (EHEC) O157:H7. EhaG is a positional orthologue of the recently characterized UpaG TAA from uropathogenic E. coli (UPEC). Similarly to UpaG, EhaG localized at the bacterial cell surface and promoted cell aggregation, biofilm formation, and adherence to a range of ECM proteins. However, the two orthologues display differential cellular binding: EhaG mediates specific adhesion to colorectal epithelial cells while UpaG promotes specific binding to bladder epithelial cells. The EhaG and UpaG TAAs contain extensive sequence divergence in their respective passenger domains that could account for these differences. Indeed, sequence analyses of UpaG and EhaG homologues from several E. coli genomes revealed grouping of the proteins in clades almost exclusively represented by distinct E. coli pathotypes. The expression of EhaG (in EHEC) and UpaG (in UPEC) was also investigated and shown to be significantly enhanced in an hns isogenic mutant, suggesting that H-NS acts as a negative regulator of both TAAs. Thus, while the EhaG and UpaG TAAs contain some conserved binding and regulatory features, they also possess important differences that correlate with the distinct pathogenic lifestyles of EHEC and UPEC

Wanted dead or alive : high diversity of macroinvertebrates associated with living and ’dead’ Posidonia oceanica matte

The Mediterranean endemic seagrass Posidonia oceanica forms beds characterised by a dense leaf canopy and a thick root-rhizome ‘matte’. Death of P. oceanica shoots leads to exposure of the underlying matte, which can persist for many years, and is termed ‘dead’ matte. Traditionally, dead matte has been regarded as a degraded habitat. To test whether this assumption was true, the motile macroinvertebrates of adjacent living (with shoots) and dead (without shoots) matte of P. oceanica were sampled in four different plots located at the same depth (5–6 m) in Mellieha Bay, Malta (central Mediterranean). The total number of species and abundance were significantly higher (ANOVA; P<0.05 and P<0.01, respectively) in the dead matte than in living P. oceanica matte, despite the presence of the foliar canopy in the latter. Multivariate analysis (MDS) clearly showed two main groups of assemblages, corresponding to the two matte types. The amphipods Leptocheirus guttatus and Maera grossimana, and the polychaete Nereis rava contributed most to the dissimilarity between the two different matte types. Several unique properties of the dead matte contributing to the unexpected higher number of species and abundance of motile macroinvertebrates associated with this habitat are discussed. The findings have important implications for the conservation of bare P. oceanica matte, which has been generally viewed as a habitat of low ecological value.peer-reviewe

Distinct ecological fitness factors coordinated by a conserved Escherichia coli regulator during systemic bloodstream infection

The ability of bacterial pathogens to adapt to host niches is driven by the carriage and regulation of genes that benefit pathogenic lifestyles. Genes that encode virulence or fitness-enhancing factors must be regulated in response to changing host environments to allow rapid response to challenges presented by the host. Furthermore, this process can be controlled by preexisting transcription factors (TFs) that acquire new roles in tailoring regulatory networks, specifically in pathogens. However, the mechanisms underlying this process are poorly understood. The highly conserved Escherichia coli TF YhaJ exhibits distinct genome-binding dynamics and transcriptome control in pathotypes that occupy different host niches, such as uropathogenic E. coli (UPEC). Here, we report that this important regulator is required for UPEC systemic survival during murine bloodstream infection (BSI). This advantage is gained through the coordinated regulation of a small regulon comprised of both virulence and metabolic genes. YhaJ coordinates activation of both Type 1 and F1C fimbriae, as well as biosynthesis of the amino acid tryptophan, by both direct and indirect mechanisms. Deletion of yhaJ or the individual genes under its control leads to attenuated survival during BSI. Furthermore, all three systems are up-regulated in response to signals derived from serum or systemic host tissue, but not urine, suggesting a niche-specific regulatory trigger that enhances UPEC fitness via pleiotropic mechanisms. Collectively, our results identify YhaJ as a pathotype-specific regulatory aide, enhancing the expression of key genes that are collectively required for UPEC bloodstream pathogenesis