1,721,115 research outputs found
Host restriction factors and Human immunodeficiency Virus (HIV-1): a dynamic interplay involving all phases of the viral life cycle
No full textMammalian cells have evolved several mechanisms to prevent or block lentiviral infection and spread. Among the innate immune mechanisms, the signaling cascade triggered by type I interferon (IFN) plays a pivotal role in limiting the burden of HIV-1. In presence of IFN, human cells upregulate the expression of a number of genes, referred to as IFN-stimulated genes (ISGs), many of them acting as antiviral restriction factors (RFs). RFs are dominant proteins that target different essential steps of the viral cycle, thereby providing an early line of defense against the virus. The identification and characterization of RFs have provided unique insights into the molecular biology of HIV-1, further revealing the complex host-pathogen interplay that characterizes the infection. The presence of RFs drove viral evolution, forcing the virus to develop specific proteins to counteract their activity. The knowledge of the mechanisms that prevent viral infection and their viral counterparts may offer new insights to improve current antiviral strategies. This review provides an overview of the RFs targeting HIV-1 replication and the mechanisms that regulate their expression as well as their impact on viral replication and the clinical course of the disease
Comparison of MycoPrep and the new MYCO-TB kit: rapid and efficient digestion and decontamination of respiratory specimens for the detection of Mycobacteria
No full textThe long incubation time required for Mycobacteria detection may allow cultures to become overgrown by contaminating organisms. Therefore, samples need to be decontaminated before solid and liquid culture. MYCO-TB is a ready-to-use digestion and decontamination kit with single-sample formulation developed by Copan. Sample processing time (3 minutes) is shorter than that of other commercial kits. The aim of this study was to compare the performance of MYCO-TB with MycoPrep, both based on N-acetyl-Lcysteine and sodium hydroxide solution, in terms of culture contamination and Mycobacterial detection by culture. We tested 162 respiratory samples: the overall proportions of contamination of both liquid and solid media were 1.8% for MYCO-TB and 1.8% for MycoPrep. Mycobacterial growth was detected without significant differences in times to positivity (TTP) in liquid culture: 10.5 days for MYCO-TB and 11.1 days for MycoPrep. Samples decontaminated with MYCO-TB were suitable for molecular assays such as Xpert MTB/RIF Ultra and GenoType CMdirect. Extending decontamination times (up to 10 minutes) with MYCO-TB of 20 Mycobacteria-positive specimens did not produce any difference in TTP in liquid culture or in Ultra IS1081/IS6110 probe Ct values. In conclusion, the MYCO-TB kit proved to be effective for the rapid digestion and decontamination of respiratory materials for the detection of Mycobacteria, making it possible to reduce the manual skills required and lower the risk of contamination. Longer decontamination time could be used for samples with a high level of contamination, such as those from cystic fibrosis patients
Conflicting interpretations of the prevalence of mutations associated with drug resistance in antiviral naive HIV-1 patients with acute and chronic infection
No full textThe routine determination of drug resistance in newly HIV-1 infected individuals records a potential increase in transmissions of drug-resistant variants. Plasma samples from 38 individuals classified as newly infected (seroconversion time <12 months) and twenty four individuals with an established infection (seroconversion time ranging from 3 to 10 years) were analyzed for the presence of mutations by Trugene HIV-1 genotyping assay and Virtual phenotype. Results on the newly infected and the chronically infected individuals showed a limited number of relevant mutations associated with substantial resistance to reverse transcriptase and protease inhibitors. In particular, three patients (4.8%) carried viral major mutations (T69D and M41L) associated with resistance to reverse transcriptase inhibitors, whereas only one showed the presence of M46L, which is correlated with partial resistance to some protease inhibitors. The clinical interpretation based on different approaches to monitor resistance showed that the Virconet interpretation was less grave than Trugene, suggesting that these interpretations need standardization for the currently used sequencing methods and that they may be associated with different outcomes when eventually are used
Comparison of the Aptima HIV-1 Quant Dx Assay with the COBAS® AmpliPrep/COBAS® TaqMan® HIV-1 v2.0 Test for HIV-1 Viral Load Quantification in Plasma Samples from HIV-1-Infected Patients.
Full text linkBackground and aims: HIV‐1 RNA viral load (VL) in plasma samples of HIV‐1–positive
patients is used to assess the level of viral replication, the risk of disease progression, and the
response and efficacy to antiretroviral treatment. Knowing the performance of different tests
for HIV‐1 RNA detection is, therefore, important for clinical care. This study compared the performance
of the recently introduced Aptima HIV‐1 Quant Dx assay (Hologic, Inc) and the standard
COBAS AmpliPrep/COBAS TaqMan HIV‐1 v2.0 Test (CAP/CTM2) (Roche Molecular System,
Inc) for HIV‐1 RNA quantitation.
Methods: Assay performance was assessed using 335 clinical samples, a standard HIV‐1 low
VL panel, and 2 diluted samples from well‐characterized patients infected with different HIV‐1
subtypes tested in 5 replicates over 3 days. All samples were tested on both assays to evaluate
inter‐assay agreement, both qualitatively and quantitively. Altogether, we evaluated assay sensitivity,
linearity, accuracy, precision, repeatability, and reproducibility.
Results: Assay agreement for qualitative results in 335 clinical samples was fair (80.6%). Correlation
of quantitative assay results (n = 164) was excellent (R2 = 0.97), with 96.3% of the results
within the 95% limit of assay agreement (−0.42 to +0.86 log), and 98.8% within 1 log of each
other. Aptima‐HIV‐1 yielded results, on average, 0.22 log higher than CAP/CTM2. Both assays
accurately quantitated the HIV‐1 standard at low VL (R2 ≥ 0.94), with all samples within 0.5 log
of the target.
Conclusion: Aptima‐HIV‐1 assay demonstrated sensitivity, accuracy, reproducibility, and precision
for the detection and quantitation of HIV‐1 RNA across a wide dynamic range of VLs. Its
performance, together with full automation and high throughput, suggests that Aptima‐HIV‐1
could be a suitable assay for reliable monitoring of HIV‐1 VL in patients undergoing treatment
Acute onset myopericarditis as unusual presentation of primary HIV infection
No full textA 30-year-old man was admitted to hospital after complaining of a retrosternal burning pain, radiating to the jugular region, and to both upper limbs. An electrocardiography examination showed a ST segment elevation involving the lower-lateral leads. A trans-thoracic ultrasonography showed findings compatible with an acute myopericarditis. All performed serological testings excluded other recent infections with cardiac tropism. Among screening tests, a peripheral lymphocyte subset analysis was performed and an inversion of the CD4/CD8 ratio was found. Therefore, HIV testing was performed and proved positive for HIV-1 antibodies. The discovery of a primary HIV infection with involvement of a vital organ led us to start HAART. On day 20, our patient underwent a right heart catheterization and endomyocardial biopsy. During the following days, the clinical conditions of our patient improved, and a further heart ultrasonography documented a mild pericardial thickening as a result of the recent myopericarditis. Also the evolving changes of ECG were compatible with a benign evolution of myopericarditis. The histopathologic studies revealed a mild fibrosis of the myocardial right ventricular tissue, and inflammatory findings compatible with a recent myocarditis. At the real-time PCR analysis on bioptic sample, only HHV6 DNA and HIV-DNA were reactive. An immunofluorescence staining was performed to highlight the HIV p24 protein and a positive signal was detected in myocardial tissue. Considering the low avidity level of the anti-HIV IgG antibodies and the positivity of HIV-DNA in the endomyocardial tissue, we believe that the clinical manifestation presented can be referred to the recent primary HIV-infection
Clinical management of dyslipidaemia associated with combination antiretroviral therapy in HIV-infected patients
No full textThe introduction of potent combination antiretroviral therapy (cART) has had a remarkable impact on the natural history of HIV infection, leading to a dramatic decline in the mortality rate and a considerable increase in the life expectancy of HIV-positive people. However, cART use is frequently associated with several metabolic complications, mostly represented by lipid metabolism alterations, which are reported very frequently among persons treated with antiretroviral agents. In particular, hyperlipidaemia occurs in up to 70%-80% of HIV-positive subjects receiving cART and is mainly associated with specific antiretroviral drugs belonging to three classes of antiretroviral agents: NRTIs, NNRTIs and PIs. The potential long-term consequences of cART-associated dyslipidaemia are not completely understood, but an increased risk of premature coronary heart disease has been reported in HIV-infected patients on cART, so prompt correction of lipid metabolism abnormalities is mandatory in this population. Dietary changes, regular aerobic exercise and switching to a different antiretroviral regimen associated with a more favourable metabolic profile are the first steps in clinical management, but lipid-lowering therapy with fibrates or statins is often required. In this case, the choice of hypolipidaemic drugs should take into account the potential pharmacokinetic interactions with many antiretroviral agents
Genital and extra-genital Chlamydia trachomatis and Neisseria gonorrhoeae infections in young women attending a Sexually Transmitted Infections (STI) clinic
No full textChlamydia trachomatis and Neisseria gonorrhoeae are the most common agents of bacterial sexually transmitted infections (STIs) worldwide. Here, we evaluated genital and extra-genital C. trachomatis and N. gonorrhoeae infection prevalence in a cohort of young women attending an STI Outpatients Clinic in Italy. From May 2019 to December 2019, 134 women aged 18-26 years were enrolled. A vaginal, a pharyngeal and a rectal swab for the molecular detection of C. trachomatis and N. gonorrhoeae were collected from each patient. Chlamydia-positive samples underwent a molecular genotyping based on pmpH gene. Total prevalence of C. trachomatis and N. gonorrhoeae infections was 17.9% and 11.2%, respectively. Chlamydial infections were prevalent in the urogenital (16.4%) and rectal (13.4%) sites, whereas N. gonorrhoeae predominated in the genital (7.4%) and pharyngeal (6%) mucosa. Overall, 5.2% of cases would have been missed if extra-genital sites had not been tested. Notably, 60% of women with a rectal infection did not report anal sex. A history of sexual contacts with a positive partner (P=0.03) and a history of ≥3 partners in the last 6 months (P=0.0075) were highly predictive of a bacterial STI. No cases of lymphogranuloma venereum were found. These data could help set up effective strategies to prevent the spread of STIs
RILEVAZIONE DELLA STRUTTURA MOSAICO DEL GENE PENA IN SEDE ORO-FARINGEA
No full textIntroduzione. Le infezioni faringee da Neisseria gonorrhoeae sono alquanto frequenti tra i soggetti omosessuali (MSM). Questo dato è di particolare rilevanza, dal momento che l’oro-faringe rappresenta un sito cruciale per l’emergenza di resistenze multiple in N. gonorrhoeae. Infatti, è stato riportato che la struttura a mosaico penA, osservata in alcuni isolati di gonococco e associata a una ridotta suscettibilità e resistenza alle cefalosporine a spettro esteso, è dovuta alla ricombinazione con geni penA, ritrovabili in ceppi di N. meningitidis o specie di Neisseria commensali dell’oro-faringe. Nel nostro lavoro abbiamo voluto investigare la prevalenza della struttura mosaico del gene penA nell’oro-faringe di MSM, negativi per infezioni faringee da gonorrea. Materiali e metodi. Da Gennaio 2016 a Giugno 2018, sono stati arruolati 351 pazienti afferenti l’ambulatorio MTS del policlinico S. Orsola-Malpighi di Bologna, che riportavano rapporti orali non protetti e negativi per N. gonorrhoeae a livello faringeo. I tamponi faringei sono stati analizzati tramite una multiplex Real-Time PCR (Versant CT / GC DNA 1.0 Assay, Siemens), che rileva, simultaneamente, la presenza del genoma di N. gonorrhoeae e C. trachomatis. A partire dal DNA estratto dei campioni negativi, è stata seguita una Real-Time PCR per la rilevazione del mosaico penA. Per confermare la presenza della struttura mosaico, gli amplificati sono stati sequenziati e gli elettroferogrammi ottenuti sono stati analizzati tramite BLAST (https://blast.ncbi.nlm.nih.gov/Blast.cgi). Per valutare le differenze statisticamente significative è stato utilizzato il t-test per confrontare i dati quantitativi, mentre i dati categorici sono stati analizzati con il test Chi-quadro. Un valore di P <0.05 è stato considerato significativo. Lo studio ha ricevuto parere favorevole da parte del comitato etico del Policlinico (78/2017/U/Tess). Risultati. L’età media dei soggetti arruolati era di 33.7 ± 10.3 anni e il 20.2% dei pazienti è risultato HIV-positivo. Più dell’8% dei soggetti sono risultati positivi alla presenza del mosaico penA, senza che questo dato fosse influenzato da età o stato di HIV. In generale, tutti i campioni penA positivi hanno mostrano una elevata sovrapponibilità (90.1%-99.4%) con sequenze depositate su BLAST di ceppi di Neisseria noti per la loro positività al mosaico penA. Conclusioni. I nostri dati potrebbero aiutare ad impostare strategie innovative per il controllo e la prevenzione delle resistenze antibiotiche di N. gonorrhoeae. Uno screening faringeo per il gene penA in soggetti negativi per la gonorrea faringea, ma con un rischio particolarmente elevato di andare incontro a tale infezione, potrebbe aprire la via a protocolli per la de-colonizzazione da specie di Neisseria commensali, in casi selezionati
No correlation between statin exposure and incident diabetes mellitus in HIV-1-infected patients receiving combination antiretroviral therapy
Full text linkObjectives: Recent clinical studies and one meta-analysis have shown a modest but significant increase in the incidence of diabetes mellitus associated with statin exposure, so this correlation was investigated in a cohort of HIV-positive subjects. Methods: A retrospective cohort study including adult HIV-1-infected patients followed at our Clinic of Infectious Diseases between 2007 and 2014 was performed. Results: We assessed 3170 HIV-positive patients with a median follow-up of 5.2 years. The incidence of diabetes mellitus was 1.2 per 100 person-years and it was not significantly associated with the prescription of statins [hazard ratio (HR) 1.09 per year of statin exposure; 95% confidence interval (CI) 0.7-1.49; P = 0.067], while it was associated with older age, chronic hepatitis C, antiretroviral-naïve vs. antiretroviral experienced condition, high body mass index, and high serum concentration of triglycerides. Conclusions: In our study, a higher risk of diabetes mellitus was not associated with statin treatment, but with some traditional risk factors
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