The major human and avian E. coli ST clones associated with multidrug resistance were identified. A subset of ST clones belonging to CC10 and CC23 poses a potential zoonotic risk.

The enhancer complex regulatory region at the 3V of the immunoglobulin heavy cluster (IgH3VEC) is duplicated in apes along with four constant genes and the region is highly conserved throughout humans. Both human IgH3VECs consist of three loci high sensitive (HS) to DNAse I with enhancer activity. It is thus possible that the presence of structural divergences between the two IgH3VECs and of relative polymorphisms correspond to functional regulatory changes. To analyse the polymorphisms of these almost identical regions, it resulted mandatory to identify the presence of divergent sequences, in order to select distinctive primers for specific PCR genomic amplifications. To this aim, we first compared the two entire IgH3VECs in silicio, utilising the updated GenBank (GB) contigs, then we analysed the two IgH3'ECs by cloning and sequencing amplicons from independent genomes. In silicio analysis showed that several inversions, deletions and short insertions had occurred after the duplication. We analysed in detail, by sequencing specific regions, the polymorphisms occurring in enhancer HS1,2-A (which lies in IgH3VEC-1, 3V to the Ca-1 gene) and in enhancer HS1,2-B (which lies in IgH3VEC-2, 3V to Ca-2). Polymorphisms are due to the repetition (occurring one to four times) of a 38-bp sequence present at the 3V of the core of enhancers HS1,2. The structure of both human HS1,2 enhancers has revealed not yet described polymorphic features due to the presence of variable spacer elements separating the 38-bp repetitions and to variable external elements bordering the repetition cluster. We found that one of the external elements gave rise to a divergent allele 3 in the two clusters. The frequency of the different alleles of the two loci varies in the Italian population and allele 3 of both loci are very rare. The analysis of the Callicebus moloch, Gorilla gorilla and Pan troglodytes HS1,2 enhancers showed the transformation from the ancestral structure with the 31-to the 17-bp external element in hominids.The relevance of the polymorphisms in the HS1,2 enhancers is due to the variable number of binding sites for the transcription factors: NF-nB, CMYB, BSAP1/2, AP1/4, E47, MyoD and AE5 and thus to the possible influence of these variations on switch, production of Ig and on maturation of B cells.

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MDRO colonization is common among residents in Italian LTCFs.

Fourteen plasmids carrying blaCTX -M-1, blaSHV -12 or blaCMY -2 genes from Escherichia coli of both avian and human origin were analysed. IncI1 plasmids were largely predominant. Plasmid mutilocus sequence typing and comparative analysis revealed that the blaCMY -2 -ST12-IncI1 plasmids from avian E. coli were identical to those previously found in Salmonella from humans, but different to those associated with human E. coli. The IncI1-ST3 plasmids carrying blaCTX -M-1 or blaSHV -12 were related to those previously identified in avian E. coli, but different to those identified in human E. coli. Overall, no plasmids shared by E. coli of both origin (human/avian) were identified; however, further investigations are needed.