The first KPC-3-producing K. pneumoniae isolates detected in the UK were highly genetically related to a KPC-3-producing Israeli K. pneumoniae strain. This relatedness was consistent with the history of one UK patient, who had been hospitalized previously in Israel. However, this strain may be circulating more widely since the second UK patient had no identifiable links with Israel or other overseas countries.

ObjectiveThe aim of the study was to evaluate the use of proviral DNA as a source of viral genetic material for genotypic coreceptor tropism testing (GTT). MethodsGTT consisted of bulk V3 sequencing followed by geno2pheno interpretation with the interpretative cut-off [false positive rate (FPR)] set at 5 and 10%. GTT was performed for 165 patients with a viral load of 4500 HIV-1 RNA copies/mL on simultaneously collected plasma RNA and proviral DNA, and for 126 patients with a viral load of o500 copies/mL on current proviral DNA and pretreatment plasma RNA. Phenotypic tropism testing (PTT) results were available for 142 samples. ResultsIn the simultaneous RNA/DNA comparison, concordance in prediction was 95.2% (at FPR 10%) and 96.4% (at FPR 5%). Six RNA-R5/DNA-X4 and two RNA-X4/DNA-R5 discordances were observed at an FPR of 10%, and six RNA-R5/DNA-X4 discordances were observed at an FPR of 5%. In the longitudinal RNA/DNA comparison, concordance was 88.1% (at FPR 10%) and 90.5% (at FPR 5%). Eight RNA-X4/DNA-R5 and seven RNA-R5/DNA-X4 discordances were seen at an FPR of 10%, and 10 RNA-R5/DNA-X4 and two RNA-X4/DNA-R5 discordances at an FPR of 5%. The overall concordance of RNA GTT with PTT was 82% (at FPR 10%) and 83% (at FPR 5%). The overall concordance of DNA GTT with PTT was 85% (at both 10 and 5% FPRs). ConclusionsGTT produced highly concordant tropism predictions for proviral DNA and plasma RNA. GTT on proviral DNA offers a promising approach for tropism prediction in clinical practice, particularly for the assessment of treated patients with low or suppressed viraemia.Keywords: chemokine (C-C motif) receptor 5 (CCR5) inhibitors, genotypic tropism testing, HIV-1 coreceptor, HIV-1 proviral DNA Accepted 25 January 2011Introduction Chemokine (C-C motif) receptor 5 (CCR5) antagonists, members of the class of HIV-1 entry inhibitors, selectively inhibit the replication of CCR5-using (R5) viral strains. Before introducing a CCR5 antagonist as a component of antiretroviral therapy (ART), coreceptor usage, or viral tropism, must be determined to exclude the possibility of the presence of chemokine (C-X-C motif) receptor 4 (CXCR4)-using (X4) strains, as these are associated with poor virological response to the drug [1]. The output of the earliest HIV-1 phenotypic tropism testing (PTT) assay was the formation of syncytia in cultured MT2 cells after virus inoculation. This assay is less well suited for use in routine clinical practice because of inherent difficulties with Correspondence: Prof. Chris Verhofstede, AIDS Reference Laboratory, University Hospital, De Pintelaan 185, B-9000 Ghent, Belgium. Tel: 1 32 9 332 51 61; fax: 1 32 9 332 38 41; e-mail: Chris.verhofstede@ugent.be DOI: 10.1111/j.1468-1293.2011.00922.x HIV Medicine (2011 GTT is based on analysis of the V3-loop sequence of the HIV-1 envelope (env) gene using bioinformatic prediction models to deduce coreceptor usage. GTT has the advantage of being less technically demanding, more rapid and less expensive than PTT, thereby meeting today's need for a fast and...

Clinical and microbiological efficacies of temocillin are unaffected by ESBL/dAmpC production, confirming its potential application as a carbapenem-sparing agent. Both CCR and MCR are optimized by a regimen of 2 g twice daily ORAE in ESBL/dAmpC-positive infection.

Background: Maraviroc (MVC) has shown good efficacy and tolerability in treatment-naive and treatment-experienced HIV-1-infected patients with CCR5-tropic virus. Data on patients switching to MVC while on suppressive antiretroviral therapy (ART) are limited. The aim of this study was to evaluate patients on suppressive ART switching to an MVC-containing regimen (MVC-CR), and test the hypothesis that the switch may have an impact on T cell activation. Methods: The study population comprised 20 treated adults who started MVC with a plasma HIV-1-RNA load (viral load, VL) of <50 copies/ml. Viral tropism was assessed by V3 loop sequencing using proviral DNA from peripheral blood mononuclear cells (PBMCs). Changes in clinical and laboratory parameters were evaluated at a median of 2 and 6 months of follow-up. T cell activation was determined by measuring soluble CD30 in plasma. Results: Reasons for switching to a MVC-CR were drug toxicity and tolerability, low CD4 cell count and ART simplification. Over median 7.5 months of follow-up, 3/20 patients discontinued MVC due to severe headache, fatigue and VL rebound. A significant reduction in soluble CD30 levels in MVC-treated patients was observed during follow-up at both 2 (p = 0.027) and 6 months (p = 0.001). Conclusions: Switching suppressive ART to a MVC-CR based upon genotypic tropism prediction from proviral DNA improves tolerability. The observed impact on T cell activation warrants further investigation.