In this work, we have studied the in vitro translational features of a bicistronic mRNA of the extremely thermophilic Archaeon Sulfolobus solfataricus, with the aim of determining the nature of the cis-acting signals controlling the recognition of the translation initiation sites in the Archaea. We found that the most important feature for efficient initiation was the presence of a Shine-Dalgarno (SD)-like ribosome-binding motif, whose disruption entirely abolished the translation of the corresponding cistron. The influence of other features, such as the type of initiation codon, was variable and depended upon the gene and its position in the mRNA. However, the translational block caused by the disruption of the SD sequences could be removed by deleting the 5' untranslated region altogether, thereby creating a 'leaderless' mRNA. This suggests that 'leaderless' initiation operates by a default mechanism that does not require a specific mRNA-rRNA interaction and may be common to all three primary domains of life

Whole genome sequences of SARS-CoV-2 obtained from two patients, a Chinese tourist visiting Rome and an Italian, were compared with sequences from Europe and elsewhere. In a phylogenetic tree, the Italian patient’s sequence clustered with sequences from Germany while the tourist’s sequence clustered with other European sequences. Some additional European sequences in the tree segregated outside the two clusters containing the patients’ sequences. This suggests multiple SARS-CoV-2 introductions in Europe or virus evolution during circulation.

Background: The genome of Bacillus anthracis, the etiological agent of anthrax, is highly monomorphic which makes differentiation between strains difficult. A Multiple Locus Variable-number tandem repeats (VNTR) Analysis (MLVA) assay based on 20 markers was previously described. It has considerable discrimination power, reproducibility, and low cost, especially since the markers proposed can be typed by agarose-gel electrophoresis. However in an emergency situation, faster genotyping and access to representative databases is necessary.

BackgroundEndemic presence of Klebsiella pneumoniae resistant to carbapenem in Italy has been due principally to the clonal expansion of CC258 isolates; however, recent studies suggest an ongoing epidemiological change in this geographical area.Methods50 K. pneumoniae strains, 25 carbapenem-resistant (CR-Kp) and 25 susceptible (CS-Kp), collected from march 2014 to march 2016 at the Laboratory of Bacteriology of the Paolo Giaccone Polyclinic University hospital of Palermo, Italy, were characterized for antibiotic susceptibility and fully sequenced by next generation sequencing (NGS) for the in silico analysis of resistome, virulome, multi-locus sequence typing (MLST) and core single nucleotide polymorphism (SNP) genotypesResultsMLST in silico analysis of CR-Kp showed that 52% of isolates belonged to CC258, followed by ST395 (12%), ST307 (12%), ST392 (8%), ST348 (8%), ST405 (4%) and ST101 (4%). In the CS-Kp group, the most represented isolate was ST405 (20%), followed by ST392 and ST15 (12%), ST395, ST307 and ST1727 (8%). The in silico β-lactamase analysis of the CR-Kp group showed that the most detected gene was blaSHV (100%), followed by blaTEM (92%), blaKPC (88%), blaOXA (88%) and blaCTX-M (32%). The virulome analysis detected mrk operon in all studied isolates, and wzi-2 was found in three CR-Kp isolates (12%). Furthermore, the distribution of virulence genes encoding for the yersiniabactin system, its receptor fyuA and the aerobactin system did not show significant distribution differences between CR-Kp and CS-Kp, whereas the Klebsiella ferrous iron uptake system (kfuA, kfuB and kfuC genes), the two-component system kvgAS and the microcin E495 were significantly (p < 0.05) prevalent in the CS-Kp group compared to the CR-Kp group.Core SNP genotyping, correlating with the MLST data, allowed greater strain tracking and discrimination than MLST analysis.ConclusionsOur data support the idea that an epidemiological change is ongoing in the Palermo area (Sicily, Italy). In addition, our analysis revealed the co-existence of antibiotic resistance and virulence factors in CR-Kp isolates; this characteristic should be considered for future genomic surveillance studies.

The 60 kDa molecular chaperones (chaperonins) are high molecular weight protein complexes having a characteristic double-ring toroidal shape; they are thought to aid the folding of denatured or newly synthesized polypeptides. These proteins exist as two functionally similar, but distantly related families, one comprising the bacterial and organellar chaperonins and another (the so-called CCT-TRiC family) including the chaperonins of the archaea and the eukaryotes. Although some evidence exists that the archaeal chaperonins are implicated in protein folding, much remains to be learned about their precise cellular function. In this work, we report that the chaperonin of the thermophilic archaeon Sulfolobus solfataricus is an RNA-binding protein that interacts specifically in vivo with the 16S rRNA and participates in the maturation of its 5Ј extremity in vitro. We further show that the chaperonin binds RNA as the native heterooligomeric complex and that RNA binding and processing are inhibited by ATP. These results agree with previous reports indicating a role for the bacterial/ organellar chaperonins in RNA protection or processing and suggest that all known chaperonin families share specific and evolutionarily ancient functions in RNA metabolism.

A highly aggressive meningococcal C strain was involved in the cluster of severe IMD occurred in Tuscany, a Region with high vaccine coverage among children. Whether this was due to low herd immunity related to the short duration of vaccine protection needs further investigation.

BackgroundIn Italy, anthrax is endemic but occurs sporadically. During the summer of 2004, in the Pollino National Park, Basilicata, Southern Italy, an anthrax epidemic consisting of 41 outbreaks occurred; it claimed the lives of 124 animals belonging to different mammal species. This study is a retrospective molecular epidemiological investigation carried out on 53 isolates collected during the epidemic. A 25-loci Multiple Locus VNTR Analysis (MLVA) MLVA was initially performed to define genetic relationships, followed by an investigation of genetic diversity between epidemic strains through Single Nucleotide Repeat (SNR) analysis.Results53 Bacillus anthracis strains were isolated. The 25-loci MLVA analysis identified all of them as belonging to a single genotype, while the SNR analysis was able to detect the existence of five subgenotypes (SGTs), allowing a detailed epidemic investigation. SGT-1 was the most frequent (46/53); SGTs 2 (4/53), 3 (1/53) 4 (1/53) and 5 (1/53) were detected in the remaining seven isolates.ConclusionsThe analysis revealed the prevalent spread, during this epidemic, of a single anthrax clone. SGT-1 - widely distributed across the epidemic area and present throughout the period in question - may, thus, be the ancestral form. SGTs 2, 3 and 4 differed from SGT-1 at only one locus, suggesting that they could have evolved directly from the latter during the course of this epidemic. SGT-5 differed from the other SGTs at 2-3 loci. This isolate, thus, appears to be more distantly related to SGT-1 and may not be a direct descendant of the lineage responsible for the majority of cases in this epidemic. These data confirm the importance of molecular typing and subtyping methods for in-depth epidemiological analyses of anthrax epidemics.

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