To establish the role of local transmission versus possible pathogen import due to previous foreign exposure in infections caused by carbapenem non-susceptible Enterobacteriaceae in the Arabian Peninsula, 200 independent isolates collected in 16 hospitals of Saudi Arabia, Kuwait, Oman and the United Arab Emirates were studied. All strains were multidrug resistant; 42.5% of them also qualified as extremely drug resistant. The frequency of various carbapenemases varied according to the participating countries, but in the collection, as a whole, bla NDM-1 was the most frequently encountered carbapenemase gene (46.5%) followed by bla OXA-48-like gene (32.5%). A comparatively high rate (8.9%) of multi-clonal strains carrying both bla NDM and bla OXA-48-like genes in the United Arab Emirates, representing the most resistant subgroup, was encountered. No KPC-expressing isolates were detected. Three major clones of bla NDM-1 carrying Klebsiella pneumoniae of ST152 (n = 22, Saudi Arabia), ST14 (n = 7, United Arab Emirates) and ST147 types (n = 9, Oman) were identified, the latter two clones carrying similar, but not identical HI1b incompatibility type plasmids of >170kb. While from 78.6% of the cases with documented foreign hospitalization bla NDM positive strains were isolated, these strains formed only 25.6% of all the isolates expressing this enzyme. In fact, 56.8% of the NDM, 75.7% of OXA-48-like and 90.9% of VIM positive strains were recovered from patients without documented foreign exposure, neither in the form of travel or prior hospitalization abroad, suggesting a high rate of autochthonous infections. This, considering the extensive links of these countries to the rest of the world, predicts that trends in the local epidemiology of carbapenem resistant strains may increasingly affect the spread of these pathogens on the global scale. These results call for improved surveillance of carbapenem resistant Enterobacteriaceae in the countries of the Arabian Peninsula.

The secondary structure of the 59 end of the FIV genome reveals a long-range interaction between R/U5 and gag sequences, and a large, stable stem-loop JULIA C. KENYON ABSTRACT Feline immunodeficiency virus (FIV) is a lentivirus that infects cats and is related to human immunodeficiency virus (HIV).Although it is a common worldwide infection, and has potential uses as a human gene therapy vector and as a nonprimate model for HIV infection, little detail is known of the viral life cycle. Previous experiments have shown that its packaging signal includes two or more regions within the first 511 nucleotides of the genomic RNA. We have undertaken a secondary structural analysis of this RNA by minimal free-energy structural prediction, biochemical mapping, and phylogenetic analysis, and show that it contains five conserved stem-loops and a conserved long-range interaction between heptanucleotide sequences 59-CCCUGUC-39 in R/U5 and 59-GACAGGG-39 in gag. This long-range interaction is similar to that seen in primate lentiviruses where it is thought to be functionally important. Along with strains that infect domestic cats, this heptanucleotide interaction can also occur in speciesspecific FIV strains that infect pumas, lions, and Pallas' cats where the heptanucleotide sequences involved vary. We have analyzed spliced and genomic FIV RNAs and see little structural change or sequence conservation within single-stranded regions of the 59 UTR that are important for viral packaging, suggesting that FIV may employ a cotranslational packaging mechanism.Keywords: FIV; lentivirus; packaging signal; dimerization; RNA INTRODUCTIONFeline immunodeficiency virus (FIV) is a lentivirus related to human immunodeficiency virus (HIV), the causative agent of AIDS (Olmsted et al. 1989;Talbott et al. 1989). Like HIV, FIV causes in its host, the domestic cat, a prolonged disease that is characterized by progressive depletion of CD4 + T cells, ultimately leading to a fatal immunodeficiency (Pedersen et al. 1987;Yamamoto et al. 1988;Siebelink et al. 1990). Many other parallels exist between the two viruses and these render FIV infection in cats a potentially useful small animal model for HIV (Olmsted et al. 1989; and reviewed in Elder et al. 2008). In addition to this, FIV is being developed as a human gene therapy vector as, like all lentiviruses, it is able to transduce nondividing cells while being associated with fewer safety concerns than primate lentiviral vectors (reviewed in Saenz and Poeschla 2004). FIV also poses a serious veterinary concern in its own right, as it infects domestic cats and big cats alike, with a worldwide distribution and a high seroprevalence (Troyer et al. 2005). A better understanding of the mechanisms of FIV replication is needed in order to utilize the virus to its full potential as an HIV model or as a gene therapy vector, and to seek ways to combat its spread in feline species. Examining the structure of functionally important regions of the FIV RNA will not only aid this, but may also enhance our understand...

Among 28 clinically relevant, carbapenem non-susceptible Enterobacteriaceae isolates collected in 2009-2011 in the United Arab Emirates three Klebsiella pneumoniae, two Escherichia coli, one Enterobacter cloacae and one Citrobacter freundi were identified to produce NDM-1 carbapenemase. Unexpectedly, with the exception of a K. pneumoniae strain, sequence type ST11, originally acquired in India and subsequently spread nosocomially in the UAE, the majority of the strains could not be directly linked to foreign travel. All isolates harboured the bla NDM-1 gene on plasmids of IncA/C, IncHI1b and IncX3 types, or were untypable. IncX3 type plasmids with a mass of 50 kb and with the same or highly similar restriction patterns, with regions flanking the bla NDM-1 gene identical to the IncX3 NDM plasmids described from China were present in three different species, Enterobacter cloacae, Escherichia coli and C. freundii. Our findings strongly support the assumptions that, beyond the Indian subcontinent, the Middle East is an important reservoir of NDM-producing organisms. Furthermore, we also provide evidence that IncX3 plasmids, recently implicated in the spread of bla NDM-1 in China, have been widely distributed and are important vehicles of the inter-species spread of the NDM-1 gene.

This is the first report on the presence of the plasmid-coded mcr-1 gene in a variety of multi-resistant clinical isolates from the Arabian Peninsula indicating that several commonly used antibiotics can potentially facilitate the spread of mcr-1 carrying strains, or directly, mcr-1 containing plasmids.

The packaging determinants of feline immunodeficiency virus (FIV) consist of two discontinuous core regions, extending from R to ϳ150 bp of the 5 untranslated region and the first ϳ100 bp of gag. However, the role of sequences intervening between the core regions in packaging has not been clear. A mutational analysis was conducted to determine whether the intervening sequences played a role in FIV RNA packaging, using an in vivo packaging assay complemented with semiquantitative reverse transcriptase PCR. Our analyses reveal that the intervening sequences are dispensable not only for vector RNA packaging but also for propagation, confirming the discontinuous nature of the FIV packaging signal.A series of recent studies have suggested that the packaging determinants of feline immunodeficiency virus (FIV) are complex and multipartite, consisting of at least two discontinuous core regions, one located upstream of the major splice donor sequence from R/U5 at the 5Ј end to the first ϳ150 bp of the 5Ј untranslated region (UTR), while the other is within the first 100 bp of gag (2, 3, 6, 7). To determine whether the region intervening between the core determinants was required for maintaining the stability of the FIV packaging signal, we modified our previously described vector, MB15 (2), and constructed a series of transfer vectors, AG002 to AG004, that maintained the R/U5 and 100 bp of gag but kept only the first 90, 120, or 150 bp of the 5Ј UTR, generating incremental deletions between the core packaging determinants (Fig. 1). In a second series, AG013 to AG015, the deletions were replaced with heterologous sequences of the same lengths to further determine whether the deleted/substituted region had a role at the structural level or acted only as a spacer (Fig. 1).The two series of mutant vector RNAs were tested for their ability to be packaged by FIV proteins, using our well-established in vivo packaging assay along with TR394, which contains the entire 270-bp UTR with a 333-bp gag sequence (1-3). The amount of transfer vector RNA packaged into viral particles was analyzed by reverse transcriptase PCR (RT-PCR) (10) for variable cycle numbers, and the resulting products were Southern blotted and hybridized using an R/U5 probe. All mutant vector RNAs, either with deletions or deletion/ substitution, were packaged into the virus particles but with different efficiencies, while the control vectors, MB15 and TR394, were packaged at similar levels ( Fig. 2A). This was despite the fact that all cultures produced similar levels of viral particles and the transfection efficiencies were within twofold of each other ( Fig. 2B and C). Since the PCRs were conducted across the deleted or deleted/substituted region, the size of the PCR fragment varied with each construct, confirming that correct packaging constructs were being expressed in each transfection.To determine the packaging efficiencies of the various constructs accurately, RT-PCRs were repeated using primers within the R/U5 region that would result in same-sized fragme...