Management of multidrug-resistant CMV infection in immunocompromised patients: case report of a heart-transplant recipient and review of the literature.

Cytomegalovirus (CMV) remains a leading cause of morbidity after solid organ transplantation. The efficiency of antivirals for the treatment of CMV infections may be hampered because of the emergence of CMV resistance to antivirals. The development of CMV multidrug resistance, which remains uncommon but does occur, constitutes a clinically challenging complication and may contribute to difficult therapeutic management and adverse clinical outcome.

Human cytomegalovirus (CMV) susceptibility to currently approved antiviral drugs does not impact on CMV terminase complex polymorphism.

Currently approved anti-human cytomegalovirus (CMV) drugs, all targeting the viral DNA polymerase, are associated with significant toxicities and emergence of drug resistance. In this context, CMV terminase complex constitutes a promising target for novel antiviral compounds. In this study, we describe the low natural polymorphism (interstrain identity >97.

High level of HIV-1 resistance in patients failing long-term first-line antiretroviral therapy in Mali.

Objectives: In resource-limited settings, few data are available on virological failure after long-term first-line antiretroviral therapy. This study characterized the genotypic resistance patterns at the time of failure after at least 36 months of a first-line regimen in Mali, West Africa.

Methods: Plasma samples from 84 patients who were receiving first-line antiretroviral treatment and with an HIV-1 RNA viral load (VL) >1000 copies/mL were analysed.

Factors associated with a low HIV reservoir in patients with prolonged suppressive antiretroviral therapy.

Objectives: The relevance of low-level HIV DNA in patients who have undergone prolonged therapy is not well understood. The objective of this study was to determine factors that influence the establishment of low-level HIV DNA in long-term treated patients (excluding treatment since acute infection).

Methods: This was a cross-sectional study involving 243 patients receiving highly active antiretroviral therapy (HAART) for ≥6 months (median: 9 years of treatment) with plasma HIV RNA <50 copies/mL at the study timepoint, for whom total DNA measurements were performed.

Surveillance of herpes simplex virus resistance to antivirals: a 4-year survey.

Herpes simplex virus (HSV) resistance to antivirals constitutes a therapeutic challenge, especially among immunocompromised patients. This observational survey on HSV resistance to antivirals was conducted retrospectively over a 4-year period (2008-2012). A total of 211 HSV-positive clinical samples (94 HSV-1 and 117 HSV-2) recovered from 139 patients (11 immunocompetent patients, 85 immunocompromised patients, and 43 patients with unknown immune status) with suspected HSV drug-resistance were analyzed for acyclovir and foscarnet susceptibility.

Molecular characterization of herpes simplex virus 2 strains by analysis of microsatellite polymorphism.

The complete 154-kbp linear double-stranded genomic DNA sequence of herpes simplex virus 2 (HSV-2), consisting of two extended regions of unique sequences bounded by a pair of inverted repeat elements, was published in 1998 and since then has been widely employed in a wide range of studies. Throughout the HSV-2 genome are scattered 150 microsatellites (also referred to as short tandem repeats) of 1- to 6-nucleotide motifs, mainly distributed in noncoding regions. Microsatellites are considered reliable markers for genetic mapping to differentiate herpesvirus strains, as shown for cytomegalovirus and HSV-1.

Polymorphism of gp41 glycoprotein might influence the progression to disease in HIV-1 infection.

We analysed the impact of envelope glycoprotein gp41 polymorphism on the persistence of long-term nonprogressor (LTNP) status in 59 HIV-1-infected individuals over a period of time exceeding 6 years. The presence of a leucine at the codon 830, instead of the predominant isoleucine residue, was significantly associated with nonprogression, independently of the presence of two particular classes of antigp41 antibodies (antigp41 IgG2 and anti-SWSNKS peptide) previously reported as markers of LTNP status.

Frequency of amino acid changes associated with resistance to attachment inhibitor BMS-626529 in R5- and X4-tropic HIV-1 subtype B.

Objectives: Resistance to attachment inhibitor BMS-626529, which inhibits the binding of HIV to CD4, involves mutations in the HIV-1 gp120 gene. There is a lack of information on the primary resistance of HIV-1 subtype B to attachment inhibitors, so we decided to investigate.

Methods: Sequences from 109 attachment-inhibitor-naive patients infected with HIV-1 subtype B were analysed for the presence of previously described in vivo resistance mutations associated with attachment inhibitor BMS-626529 and tropism determination.

Transmitted antiretroviral drug resistance in newly HIV-infected and untreated patients in Ségou and Bamako, Mali.

The WHO recommends regular surveillance for transmitted antiretroviral drug-resistant viruses in HIV antiretroviral treatment (ART)-naive patients in resource-limited settings. This study aimed to assess the prevalence of mutations associated with resistance in ART-naive patients newly diagnosed with HIV in Bamako and Ségou in Mali. HIV-positive patients who never received ART were recruited in Bamako and Ségou, Mali.

HIV-1 genome is often defective in PBMCs and rectal tissues after long-term HAART as a result of APOBEC3 editing and correlates with the size of reservoirs.

Objectives: Precise characterization of viruses present in reservoirs in long-term pretreated patients will be a major issue to consider in the context of viral eradication. We assessed the frequency of defective viruses present in cellular reservoirs.

Methods: Peripheral blood mononuclear cells (PBMCs) and rectal biopsy samples were compared between five patients on successful long-term highly active antiretroviral therapy (HAART) (>7 years without blips) and five untreated patients.

Clinical and microbiological evaluation of travel-associated respiratory tract infections in travelers returning from countries affected by pandemic A(H1N1) 2009 influenza.

Background: Although acute respiratory tract infections (RTI) have been recognized as a significant cause of illness in returning travelers, few studies have specifically evaluated the etiologies of RTI in this population.

Methods: This prospective investigation evaluated travelers returning from countries with endemic influenza A(H1N1) 2009, and who were seen in our department at the onset of the outbreak (April-July 2009). Patients were included if they presented with signs of RTI that occurred during travel or less than 7 days after return from overseas travel.

Genotypic characterization of herpes simplex virus DNA polymerase UL42 processivity factor.

The herpes simplex virus (HSV) DNA polymerase is composed of the UL30 catalytic subunit and the UL42 processivity factor. The UL42 subunit increases the processivity of the polymerase along the DNA template during replication. The molecular mechanisms of HSV resistance to drugs interfering with viral DNA synthesis reported so far mainly rely on modifications of the viral thymidine kinase and DNA polymerase.

Upgraded Cobas Ampliprep-Cobas TaqMan version 2.0 HIV-1 RNA quantification assay versus first version: correction of underestimations.

The large underestimations of HIV RNA quantification observed in 17 patients with the first version of Cobas TaqMan assay have been successfully corrected in the upgraded version 2.0. In comparison with the Abbott RealTime assay, the mean difference that was 1.

[Evaluation of the LightCycler 480 real-time PCR system for the measurement of CMV, EBV, HHV-6 and BKV viral loads in whole blood].

Objective: The Roche LightCycler 480 (LC480) system was evaluated for quantitative molecular diagnosis of opportunistic viral infections caused by human cytomegalovirus (CMV), Epstein-Barr virus (EBV), human herpesvirus 6 (HHV-6), and BK virus (BKV), in comparison with "in-house" real-time PCR assays.

Patients And Methods: A total of 253 whole blood specimens obtained from transplant recipients were tested.

Results: Both the "in-house" and the LC480 methods were highly correlated (Spearman correlation coefficient Rho> or =0.

Genetic analysis and putative role in resistance to antivirals of the human cytomegalovirus DNA polymerase UL44 processivity factor.

Background: The human cytomegalovirus (HCMV) DNA polymerase is composed of the UL54 catalytic subunit and the UL44 accessory protein. UL44 increases the processivity of polymerase along the DNA template during replication and, incidentally, is a substrate for the UL97 phosphotransferase. The molecular mechanisms of HCMV resistance to antiviral drugs interfering with viral DNA synthesis reported so far only rely on the presence of amino acid changes within the UL97 and UL54 viral enzymes.

Use of the Roche LightCycler 480 system in a routine laboratory setting for molecular diagnosis of opportunistic viral infections: Evaluation on whole blood specimens and proficiency panels.

The Roche LightCycler 480 (LC480) system was evaluated for quantitative molecular diagnosis of opportunistic viral infections caused by human cytomegalovirus (HCMV), Epstein-Barr virus (EBV), human herpesvirus 6 (HHV-6) and BK virus (BKV), in comparison with "in-house" real-time PCR assays. A total of 253 whole blood specimens obtained from transplant recipients were tested. Both the "in-house" and the LC480 methods were highly correlated (Spearman correlation coefficient Rho>or=0.

Nucleoside reverse transcriptase inhibitor-sparing regimen (nonnucleoside reverse transcriptase inhibitor + protease inhibitor) was more likely associated with resistance comparing to nonnucleoside reverse transcriptase inhibitor or protease inhibitor + nucleoside reverse transcriptase inhibitor in the randomized ANRS 121 trial.

The use of nonnucleoside reverse transcriptase inhibitor (NNRTI) + protease inhibitor regimen for the treatment of antiretroviral-naive patients was less successful than classical nucleoside reverse transcriptase inhibitor (NRTI) based regimen and associated with more resistance for protease inhibitors and NNRTIs. The selection for NNRTI resistance was particularly observed in patients with high viral load (>100 000 copies/ml) and low efavirenz trough levels (<1100 ng/ml). Contrary to the results observed in trials evaluating mono or dual protease inhibitors strategies, gag gene mutations were not involved in the low efficacy of this strategy.

Impact of discrepancies between the Abbott realtime and cobas TaqMan assays for quantification of human immunodeficiency virus type 1 group M non-B subtypes.

Viral loads in 249 clinical samples from individual patients infected with human immunodeficiency virus type 1 non-B subtypes were determined with both the Abbott RealTime and Cobas TaqMan assays. The differences exceeded 0.5 log for about 20% of samples and 1 log for 3%, with higher values always from the Abbott assay in the latter cases.

Risk factors for selection of the L74I reverse transcriptase mutation in human immunodeficiency virus type 1-infected patients.

We analyzed 3,475 human immunodeficiency virus sequences and 241 therapeutic histories. The L74I mutation was carried by 7% of viruses. L74I was strongly associated with T215F, K70R, and V75M/S/T/A mutations and increased with the number of thymidine analog mutations.

Rapid determination of antiviral drug susceptibility of herpes simplex virus types 1 and 2 by real-time PCR.

An antiviral drug susceptibility assay of herpes simplex virus (HSV) was developed using real-time PCR quantification of intracellular viral DNA load. The number of HSV DNA copies within Vero cells after 24 h infection was strongly correlated with the number of plaques obtained after 72 h infection. Antiviral drug susceptibility of HSV was determined after virus growth for 24h by measuring the reduction of intracellular HSV DNA in the presence of increasing concentrations of either acyclovir (ACV) or foscarnet (PFA).

Quantification of Kaposi's sarcoma-associated herpesvirus in blood, oral mucosa, and saliva in patients with Kaposi's sarcoma.

The aims of this study were to measure Kaposi's sarcoma-associated herpesvirus (KSHV) load in oral mucosa and blood and to determine their relationship with clinical activity of KS in both AIDS-Kaposi's sarcoma (KS) and HIV-unrelated KS patients. Among AIDS patients, KSHV viral load in peripheral blood mononuclear cells (PBMCs) was higher in patients with active KS than in patients with KS in complete remission. In HIV-unrelated KS patients, KSHV viral load in PBMCs was not correlated with clinical stage.

Quantitative analysis of human mitochondrial DNA using a real-time PCR assay.

Objectives: Known for their ability to inhibit the human DNA polymerase-gamma, nucleoside analogues induce toxic effects on mitochondria ranging from increased serum lactate levels to fatal lactic acidosis. DNA polymerase-gamma ensures the mitochondrial DNA (mtDNA) replication and, thus, its inhibition leads to the decrease of the mtDNA. We describe a real-time PCR assay for mtDNA quantification associating DNA extraction procedures applied on peripheral blood mononuclear cells (PBMCs) and subcutaneous adipose tissues and to study the antiretroviral effect on mitochondria.

HIV and antiretroviral drug distribution in plasma and fat tissue of HIV-infected patients with lipodystrophy.

Objective: To determine HIV and antiretroviral drug distribution in plasma and fat tissue of HIV-infected patients with lipodystrophy.

Methods: Twenty-three consecutive HIV-infected patients (median age, 43 years; male:female ratio, 18:5; median CD4 cell count, 419 x 10(6)/l) undergoing Coleman's lipostructure were enrolled prospectively in this study. HIV-1 RNA and plasma concentration of antiretroviral drugs were determined blindly in plasma and adipocyte lysate samples.

Multiple herpes simplex virus infections with various resistance patterns in a matched unrelated donor transplant recipient.

A 45-year-old matched unrelated BMT recipient had sequential mucocutaneous herpes simplex virus (HSV) type 2 infections. Five months after BMT, a penile lesion occurred and was cured using acyclovir, as expected from in vitro susceptibility results. The same lesion recurred 1 month later but worsened with acyclovir.