Complex patterns of protease inhibitor resistance among antiretroviral treatment-experienced HIV-2 patients from Senegal: implications for second-line therapy.

Protease inhibitor (PI)-based antiretroviral therapy (ART) can effectively suppress HIV-2 plasma load and increase CD4 counts; however, not all PIs are equally active against HIV-2, and few data exist to support second-line therapy decisions. To identify therapeutic options for HIV-2 patients failing ART, we evaluated the frequency of PI resistance-associated amino acid changes in HIV-2 sequences from a cohort of 43 Senegalese individuals receiving unboosted indinavir (n = 18 subjects)-, lopinavir/ritonavir (n = 4)-, or indinavir and then lopinavir/ritonavir (n = 21)-containing ART. Common protease substitutions included V10I, V47A, I54M, V71I, I82F, I84V, L90M, and L99F, and most patients harbored viruses containing multiple changes. Based on genotypic data, we constructed a panel of 15 site-directed mutants of HIV-2ROD9 containing single- or multiple-treatment-associated amino acid changes in the protease-encoding region of pol. We then quantified the susceptibilities of the mutants to the HIV-2 "active" PIs saquinavir, lopinavir, and darunavir using a single-cycle assay. Relative to wild-type HIV-2, the V47A mutant was resistant to lopinavir (6.3-fold increase in the mean 50% effective concentration [EC50]), the I54M variant was resistant to darunavir and lopinavir (6.2- and 2.7-fold increases, respectively), and the L90M mutant was resistant to saquinavir (3.6-fold increase). In addition, the triple mutant that included I54M plus I84V plus L90M was resistant to all three PIs (31-, 10-, and 3.8-fold increases in the mean EC50 for darunavir, saquinavir, and lopinavir, respectively). Taken together, our data demonstrate that PI-treated HIV-2 patients frequently harbor viruses that exhibit complex patterns of PI cross-resistance. These findings suggest that sequential PI-based regimens for HIV-2 treatment may be ineffective.

[Vulvar squamous cell carcinoma in a HIV-1 infected patient with first-line antiretroviral therapy failure]. / Carcinome épidermoïde de la vulve chez une patiente infectée par le VIH-1 en échec de traitement antirétroviral de première ligne.

Vulvar cancer has been rarely reported in the literature. In young women, it is most often caused by human papillomavirus (HPV), whereas in postmenopausal women, in whom this cancer is more common, it would be caused by estrogen deficiency. Moreover, HIV infection increases the risk of developing vulvar cancer in HIV-positive women as a consequence of the high prevalence of HPV infection in these subjects. Thus, in patients with suspected vulva lesion, biopsy followed by anatomo-pathological examination should be performed in order to establish the diagnosis. We here report a case of vulvar squamous cell carcinoma in a HIV-1-positive patient with first-line antiretroviral therapy (ARV) failure.

[HIV-2 infection in Senegal: virological failures and resistance to antiretroviral drugs (ARVs)]. / Infection à VIH-2 au Sénégal: échecs virologiques et résistances aux antirétroviraux (ARV).

INTRODUCTION: HIV-2, endemic in West Africa, has a natural resistance to non-nucleoside reverse transcriptase inhibitors (NNRTIs) which makes it difficult to treat it in developing countries. METHODS: We conducted a descriptive, longitudinal, prospective study over the period November 2005-June 2017. Virologic failure has been defined as any viral load greater than 50 copies/ml after 6 months of ARV treatment administered twice. Assays for detecting drug-resistance mutations was performed in the protease-coding region and in the reverse transcriptase-coding region. RESULTS: Data from a total of 110 patients were collected. The patients had a median age of 46 years (ranging from 18 to 67) with a sex-ratio F/M of 2.54. At inclusion, viral load could be assessed in 44% of cases with a median of 935cp/ml (ranging from 17 to 144038). Antiretroviral regimen consisted of a combination of 2 NRTIs and 1IP in 94% of cases. The median follow-up was 1200 days (ranging from 1 to 3840); 94 then 76 patients completed their 12-month and 24-month assessments respectively. At 24-month follow-up, 39 patients had virologic failure, reflecting a prevalence of 39% estimated at 33% at 12-month follow-up and at 11% at 24-month follow-up; NRTIs resistance was observed in 45% of patients, IP resistance in 41% of patients while multi-NRTIs resistance and multi-IP resistance in 30% of patients. CONCLUSION: Currently, there is an urgent need to make available the new therapeutic classes of ARV for second line ART for patients living with HIV-2 with therapeutic failure in resource-limited settings.

Infections caused by extended-spectrum beta-lactamases producing Enterobacteriaceae: clinical and economic impact in patients hospitalized in 2 teaching hospitals in Dakar, Senegal.

BACKGROUND: Infections caused by extended-spectrum beta-lactamases producing Enterobacteriaceae (ESBL-E) are of major concern in clinical practice because of limited therapeutic options effective to treat them. Published studies showed that ESBL-E, widely spread in Europe, United States or Asia; are also frequent in Africa. However, the impact of ESBL-E infections is yet to be adequately determined in Sub-Saharan African countries, particularly in Senegal. The aim of our study was to estimate the incidence rate of ESBL-E infections and to assess their clinical and economic impact in Senegal. METHODS: Two retrospective cohort studies were conducted in patients hospitalized from April to October 2012. A classic retrospective cohort study comparing patients infected by an Enterobacteriaceae producer of ESBL (ESBL+) and patients infected by an Enterobacteriaceae non-producer of ESBL (ESBL-) was carried out for fatal outcomes. Besides, a retrospective parallel cohort study comparing infected patients by an ESBL+ and ESBL- versus uninfected patients was carried out for the excess LOS analyses. Multivariable regression analysis was performed to identify risk factors for fatal outcomes. A multistate model and a cost-of-illness analysis were used to estimate respectively the excess length of stay (LOS) attributable to ESBL production and costs associated. Cox proportional hazards models were used to assess the independent effect of ESBL+ and ESBL- infections on LOS. RESULTS: The incidence rate of ESBL-E infections was 3 cases/1000 patient-days (95 % CI: 2.4-3.5 cases/1000 patient-days). Case fatality rate was higher in ESBL+ than in ESBL- infections (47.3 % versus 22.4 %, p = 0.0006). Multivariable analysis indicated that risk factors for fatal outcomes were the production of ESBL (OR = 5.7, 95 % CI: 3.2-29.6, p = 0.015) or being under mechanical ventilation (OR = 5.6, 95 % CI: 2.9-57.5, p = 0.030). Newborns and patients suffering from meningitidis or cancer were patients at-risk for fatal outcomes. ESBL production increased hospital LOS (+4 days) and reduced significantly the hazard of discharge after controlling for confounders (HR = 0.3, 95 % CI:0.2-0.4). The additional cost associated with ESBL-production of €100 is substantial given the lower-middle-income status of Senegal. CONCLUSION: Our findings show an important clinical and economic impact of ESBL-E infections in Senegal and emphasize the need to implement adequate infection control measures to reduce their incidence rate. An antibiotic stewardship program is also crucial to preserve the effectiveness of our last-resort antibiotic drugs.

Culture of previously uncultured members of the human gut microbiota by culturomics.

Metagenomics revolutionized the understanding of the relations among the human microbiome, health and diseases, but generated a countless number of sequences that have not been assigned to a known microorganism1. The pure culture of prokaryotes, neglected in recent decades, remains essential to elucidating the role of these organisms2. We recently introduced microbial culturomics, a culturing approach that uses multiple culture conditions and matrix-assisted laser desorption/ionization-time of flight and 16S rRNA for identification2. Here, we have selected the best culture conditions to increase the number of studied samples and have applied new protocols (fresh-sample inoculation; detection of microcolonies and specific cultures of Proteobacteria and microaerophilic and halophilic prokaryotes) to address the weaknesses of the previous studies3-5. We identified 1,057 prokaryotic species, thereby adding 531 species to the human gut repertoire: 146 bacteria known in humans but not in the gut, 187 bacteria and 1 archaea not previously isolated in humans, and 197 potentially new species. Genome sequencing was performed on the new species. By comparing the results of the metagenomic and culturomic analyses, we show that the use of culturomics allows the culture of organisms corresponding to sequences previously not assigned. Altogether, culturomics doubles the number of species isolated at least once from the human gut.

HIV-2 integrase variation in integrase inhibitor-naïve adults in Senegal, West Africa.

BACKGROUND: Antiretroviral therapy for HIV-2 infection is hampered by intrinsic resistance to many of the drugs used to treat HIV-1. Limited studies suggest that the integrase inhibitors (INIs) raltegravir and elvitegravir have potent activity against HIV-2 in culture and in infected patients. There is a paucity of data on genotypic variation in HIV-2 integrase that might confer intrinsic or transmitted INI resistance. METHODS: We PCR amplified and analyzed 122 HIV-2 integrase consensus sequences from 39 HIV-2-infected, INI-naive adults in Senegal, West Africa. We assessed genetic variation and canonical mutations known to confer INI-resistance in HIV-1. RESULTS: No amino acid-altering mutations were detected at sites known to be pivotal for INI resistance in HIV-1 (integrase positions 143, 148 and 155). Polymorphisms at several other HIV-1 INI resistance-associated sites were detected at positions 72, 95, 125, 154, 165, 201, 203, and 263 of the HIV-2 integrase protein. CONCLUSION: Emerging genotypic and phenotypic data suggest that HIV-2 is susceptible to the new class of HIV integrase inhibitors. We hypothesize that intrinsic HIV-2 integrase variation at "secondary" HIV-1 INI-resistance sites may affect the genetic barrier to HIV-2 INI resistance. Further studies will be needed to assess INI efficacy as part of combination antiretroviral therapy in HIV-2-infected patients.