Presence Of Drug Resistance Mutations Research Articles

HIV-1 drug resistance among naïve patients in Armenia in 2017–2021

Background. The increased antiretroviral therapy (ART) coverage of patients in the absence of routine drug resistance (DR) tests highlight the importance of HIV-1 drug resistance surveillance in Armenia. Aim. The aim of this study was a determination of the prevalence of HIV-1 DR on a large-scale cohort of HIV-infected citizens of the Republic of Armenia who had no experience of taking antiretroviral drugs. Materials and methods. The study was carried out on a cohort of more than 20% of PLHIV in the Republic of Armenia. The resulting 982 nucleotide sequences of the HIV-1 pol gene fragment, encoding the protease and reverse transcriptase region, as well as 367 sequences of the integrase gene, were analyzed using the Stanford University database and the CPR tool for the presence of drug resistance mutations and determination of the resistance level to ARV drugs. The HIV-1 subtype was determined using the Stanford University database and confirmed by phylogenetic analysis. Results. The overall prevalence of HIV DR to ARV drugs in naïve patients was 13.8%. Resistance to non-nucleoside reverse transcriptase inhibitors was 11.2%, nucleotide reverse transcriptase inhibitors — 1.4%, protease inhibitors — 2.0% and integrase inhibitors — 0.5%. The predominant genetic variant among viruses containing DR mutations was subtype B. Resistance was most often recorded among men who have sex with men living in Yerevan. Conclusion. In our study, prevalence of DR was high only for the NNRTI drugs. The results show that the first-line ARV drugs recommended in current national guidelines are highly likely to be effective. The analysis was carried out on a significant proportion of HIV-infected citizens of the Republic of Armenia, which increases the reliability and accuracy of the data obtained.

Identification of potential inhibitors for drug-resistant EGFR mutations in non-small cell lung cancer using whole exome sequencing data.

Epidermal growth factor receptor (EGFR) gene mutations are prevalent in about 50% of lung adenocarcinoma patients. Highly effective tyrosine kinase inhibitors (TKIs) targeting the EGFR protein have revolutionized treatment for the prevalent and aggressive lung malignancy. However, the emergence of new EGFR mutations and the rapid development of additional drug resistance mechanisms pose substantial challenge to the effective treatment of NSCLC. To investigate the underlying causes of drug resistance, we utilized next-generation sequencing data to analyse the genetic alterations in different tumor genomic states under the pressure of drug selection. This study involved a comprehensive analysis of whole exome sequencing data (WES) from NSCLC patients before and after treatment with afatinib and osimertinib with a goal to identify drug resistance mutations from the post-treatment WES data. We identified five EGFR single-point mutations (L718A, G724E, G724K, K745L, V851D) and one double mutation (T790M/L858R) associated with drug resistance. Through molecular docking, we observed that mutations, G724E, K745L, V851D, and T790M/L858R, have negatively affected the binding affinity with the FDA-approved drugs. Further, molecular dynamic simulations revealed the detrimental impact of these mutations on the binding efficacy. Finally, we conducted virtual screening against structurally similar compounds to afatinib and osimertinib and identified three compounds (CID 71496460, 73292362, and 73292545) that showed the potential to selectively inhibit EGFR despite the drug-resistance mutations. The WES-based study provides additional insight to understand the drug resistance mechanisms driven by tumor mutations and helps develop potential lead compounds to inhibit EGFR in the presence of drug resistance mutations.

HIV drug resistance among patients experiencing antiretroviral therapy failure in Russia, 2019–2021

Increasing HIV drug resistance is an important public health concern. The current study aimed to assess HIV drug resistance among people who live with HIV (PLWH) experiencing virological failure.Blood samples and epidemiological characteristics were collected in four Siberian regions from PLWH experiencing ART failure. Partial pol gene sequences were obtained for the study individuals. Drug resistance mutations (DRMs) were predicted using the Stanford HIVdb Program. The association of HIV DRM with epidemiological characteristics was estimated using logistic regression analysis. Further analysis was performed for children (0–14 y old) and adults (≥15 y old) separately.In total, 815 (89.4%) patients were included in the final dataset. Overall, 501 (61.5%) patients had DRM detected. NRTI DRM was more common in children, while NRTI+NNRTI DRM was more frequent in adults (P < 0.001). Krasnoyarsk region, male sex and high viral load were positively associated with the presence of DRM in adults, while higher CD4 cell count and PI/INSTI-based ART had a negative association. No association between epidemiological characteristics and DRM was identified in children. The remaining 38.5% of patients with virological failure had no DRM detected; those patients were likely to have insufficient ART adherence. Most (55.5%) patients had HIV CRF63_02A6, followed by sub-subtype A6 (39.2%).This study revealed poor ART adherence as a main factor driving ART failure among PLWH in the Siberian region. DRM was detected in over 60% of PLWH experiencing ART failure. The current results highlight an urgent need for the introduction of special programs focusing on ART adherence improvement.

Second-Line Switch to Dolutegravir for Treatment of HIV Infection

BackgroundData to inform the switch from a ritonavir-boosted protease inhibitor (PI) to dolutegravir in patients living with human immunodeficiency virus (HIV) infection who do not have genotype information and who have viral suppression with second-line therapy containing a ritonavir-boosted PI have been limited.MethodsIn a prospective, multicenter, open-label trial conducted at four sites in Kenya, we randomly assigned, in a 1:1 ratio, previously treated patients without genotype information who had viral suppression while receiving treatment containing a ritonavir-boosted PI to either switch to dolutegravir or continue the current regimen. The primary end point was a plasma HIV type 1 RNA level of at least 50 copies per milliliter at week 48, assessed on the basis of the Food and Drug Administration snapshot algorithm. The noninferiority margin for the between-group difference in the percentage of participants who met the primary end point was 4 percentage points. Safety up to week 48 was assessed.ResultsA total of 795 participants were enrolled, with 398 assigned to switch to dolutegravir and 397 assigned to continue taking their ritonavir-boosted PI; 791 participants (397 in the dolutegravir group and 394 in the ritonavir-boosted PI group) were included in the intention-to-treat exposed population. At week 48, a total of 20 participants (5.0%) in the dolutegravir group and 20 (5.1%) in the ritonavir-boosted PI group met the primary end point (difference, −0.04 percentage points; 95% confidence interval, −3.1 to 3.0), a result that met the criterion for noninferiority. No mutations conferring resistance to dolutegravir or the ritonavir-boosted PI were detected at the time of treatment failure. The incidence of treatment-related grade 3 or 4 adverse events was similar in the dolutegravir group and the ritonavir-boosted PI group (5.7% and 6.9%, respectively).ConclusionsIn previously treated patients with viral suppression for whom there were no data regarding the presence of drug-resistance mutations, dolutegravir treatment was noninferior to a regimen containing a ritonavir-boosted PI when the patients were switched from a ritonavir-boosted PI–based regimen. (Funded by ViiV Healthcare; 2SD ClinicalTrials.gov number, NCT04229290.)

Hepatitis B virus genotypes and drug resistance mutations circulating in blood donors in Beira, Mozambique.

Hepatitis B virus (HBV) infects nearly 300 million people and is the leading cause of hepatitis and hepatocellular carcinoma worldwide. Despite the high burden of HBV in sub-Saharan Africa, countries such as Mozambique have limited data available on circulating HBV genotypes and the presence of drug resistance mutations. Blood donors from Beira, Mozambique were tested for HBV surface antigen (HBsAg) and HBV DNA at the Instituto Nacional de Saúde in Maputo, Mozambique. Regardless of HBsAg status, donors with detectable HBV DNA were evaluated for HBV genotype. PCR was performed with primers amplifying a 2.1-2.2 kilobase fragment of the HBV genome. PCR products were submitted for next generation sequencing (NGS), and consensus sequences were evaluated for HBV genotype, recombination, and the presence or absence of drug resistance mutations. Of the 1281 blood donors tested, 74 had quantifiable HBV DNA. The polymerase gene could be amplified from 45 of 58 (77.6%) individuals with chronic HBV infection and 12 of 16 (75%) with occult HBV infection. Among these 57, 51 (89.5%) sequences belonged to HBV genotype A1, while 6 (10.5%) were HBV genotype E. All genotype E sequences were E/A recombinants, and clustered separately from other genotype E references. Genotype A samples had a median viral load of 637 IU/mL, while genotype E samples had a median viral load of 476,084 IU/mL. No drug resistance mutations were observed in the consensus sequences. The current study demonstrates the genotypic diversity of HBV in blood donors in Mozambique, but the absence of dominant (consensus) drug resistance mutations. Studies in other at-risk populations are essential for understanding the epidemiology, risk of liver disease, and likelihood of treatment resistance in resource-limited settings.

HIV-1 integrase resistance associated mutations and the use of dolutegravir in Sub-Saharan Africa: A systematic review and meta-analysis.

As sub-Saharan Africa (SSA) countries are transitioning to dolutegravir (DTG)-based ART, baseline data are required for optimal monitoring of therapeutic response. In this frame, we sought to generate up-to-date evidence on the use of integrase-strand transfer inhibitors (INSTI) and associated drug resistance mutations (DRMs) within SSA. In this systematic review and meta-analysis, we included randomized and non-randomized trials, cohort-studies, cross-sectional studies, and case-reports published on INSTI or integrase DRMs in SSA. We included studies of patients exposed to DTG, raltegravir (RAL) or elvitegravir (EVG). Primary outcomes were "the rate of virological control (VC:<50copies/ml)" and "the presence of DRMs" on INSTI-based regimens among patients in SSA. We synthesised extracted data using subgroup analysis, and random effect models were used where appropriate. Additional analyses were conducted to assess study heterogeneity. We identified 1,916 articles/citations through database searches, of which 26 were included in the analysis pertaining to 5,444 patients (mean age: 37±13 years), with 67.62% (3681/5444) female. Specifically, 46.15% (12/26) studies focused on DTG, 26.92% (7/26) on RAL, 23.08% (6/26) on both DTG and RAL, and 3.85% (1/26) on EVG. We found an increasing use of DTG overtime (0% before 2018 to 100% in 2021). Median treatment duration under INSTI-based regimens was 12 [9-36] months. Overall, the rate of VC was 88.51% [95%CI: 73.83-97.80] with DTG vs. 82.49% [95%CI: 55.76-99.45] and 96.55% [95%CI: 85.7-100.00] with RAL and EVG, respectively. In univariate analysis, VC with DTG-containing vs. other INSTI-regimens was significantly higher (OR = 1.44 [95%CI: 1.15-1.79], p = 0.0014). Among reported DRMs at failure, the only DTG resistance-mutations were G118R and R263K. In SSA, DTG presents a superiority effect in VC compared to other INSTIs. Nonetheless, the early detection of INSTI-DRMs calls for sentinel surveillance for a successful transition and a sustained efficacy of DTG in SSA. PROSPERO Registration Number: CRD42019122424.

HIV-1 drug resistance mutations among individuals with low-level viraemia while taking combination ART in Botswana.

To assess whether a single instance of low-level viraemia (LLV) is associated with the presence of drug resistance mutations (DRMs) and predicts subsequent virological failure (VF) in adults receiving ART in 30 communities participating in the Botswana Combination Prevention Project. A total of 6078 HIV-1 C pol sequences were generated and analysed using the Stanford HIV drug resistance database. LLV was defined as plasma VL = 51-999 copies/mL and VF was defined as plasma VL ≥ 1000 copies/mL. Among 6078 people with HIV (PWH), 4443 (73%) were on ART for at least 6 months. Of the 332 persons on ART with VL > 50 copies/mL, 175 (4%) had VL ≥ 1000 copies/mL and 157 (4%) had LLV at baseline. The prevalence of any DRM was 57 (36%) and 78 (45%) in persons with LLV and VL ≥ 1000 copies/mL, respectively. Major DRMs were found in 31 (20%) with LLV and 53 (30%) with VL ≥ 1000 copies/mL (P = 0.04). Among the 135 PWH with at least one DRM, 17% had NRTI-, 35% NNRTI-, 6% PI- and 3% INSTI-associated mutations. Among the 3596 participants who were followed up, 1709 (48%) were on ART for ≥6 months at entry and had at least one subsequent VL measurement (median 29 months), 43 (3%) of whom had LLV. The OR of experiencing VF in persons with LLV at entry was 36-fold higher than in the virally suppressed group. A single LLV measurement while on ART strongly predicted the risk of future VF, suggesting the use of VL > 50 copies/mL as an indication for more intensive adherence support with more frequent VL monitoring.

Viral load as a risk factor of reverse transcriptase inhibitor drug resistance mutation in antiretroviral-treated people living with HIV/AIDS

Background The human immunodeficiency virus type 1 (HIV-1) is a major contagion faced by the population of Indonesia. The success of antiretroviral treatment (ART) is threatened by the emergence of drug resistance mutations (DRM). The aim of this study was to determine the association between CD4 count, CD4 count changes, viral load, adherence to therapy, and therapy history in the presence of DRM in people living with HIV/AIDS (PLWHA). MethodsThis was a cross-sectional study involving 269 adults who underwent antiretroviral (ARV) therapy for at least 6 months. The frequencies of DRM and polymorphisms were measured by partial amplification of the reverse transcriptase (RT) gene using RT-nested PCR on samples with viral loads of &gt;1000 copies/mL. Sequencing was performed using the Sanger method, and edited by BioEdit. The edited sequences were submitted to http://hivdb.stanford.edu for DRM determination. Respondents’ medical data, CD4 count, viral load, and DRM were analyzed by simple and multiple logistic regression. ResultsThe multiple logistic regression analysis showed a significant association of CD4 count (aOR=12.47; 95% CI: 1.45 -107.39; p=0.023) and viral load at the time of study (aOR=29.56; 95% CI: 3.47-251.52; p=0.002) with the presence of DRM in respondents. ARV substitution history was not associated with the presence of DRM. There were 17 respondents (6.3%) carrying HIV-1 DRM, with M184V/I (11 sequences) as the most frequent pattern of NRTI resistance, and K103 (9 sequences) as that of NNRTI resistance. ConclusionThis study demonstrated that viral load at the time of the study was the most influential determinant factor for the presence of DRM in PLWHA.

HIV-1 Drug Resistance Among Treatment-Naive Transgenders from India.

Transgenders (TGs) are highly affected by HIV with high prevalence of 3.14% in India. Since 2017, targeted preventive efforts have been initiated by the government and HIV-infected TGs are being provided the antiretroviral (ART) treatment. Information on the primary HIV drug resistance is crucial for appropriate treatment selection to curb further spread of HIV in this population. In this study, we analyzed HIV-1 pol gene sequences from 36 TGs for presence of drug resistance mutations. To our knowledge, this first study from India reports high-level primary drug resistance (13.8%) among the TG population. Mutations M184V, A98G, K103N, G190A, and Y318F associated with resistance to nucleoside reverse transcriptase inhibitor and non-nucleoside reverse transcriptase inhibitors were observed. All pol gene sequences revealed HIV-1 subtype C in all study TG. High-level HIV-1 drug resistance warrant nationwide larger studies on TGs to understand the level of primary ART drug resistance among this population.

Diversity of the hepatitis C virus NS5B gene during HIV co-infection.

Viral diversity is an important feature of hepatitis C virus (HCV) infection and an important predictor of disease progression and treatment response. HIV/HCV co-infection is associated with enhanced HCV replication, increased fibrosis, and the development of liver disease. HIV also increases quasispecies diversity of HCV structural genes, although limited data are available regarding the impact of HIV on non-structural genes of HCV, particularly in the absence of direct-acting therapies. The genetic diversity and presence of drug resistance mutations within the RNA-dependent RNA polymerase (NS5B) gene were examined in 3 groups of women with HCV genotype 1a infection, including those with HCV mono-infection, antiretroviral (ART)-naïve women with HIV/HCV co-infection and CD4 cell count <350 cells/mm3, and ART-naïve women with HIV/HCV co-infection and CD4 cell count ≥350 cells/mm3. None had ever been treated for HCV infection. There was evidence of significant diversity across the entire NS5B gene in all women. There were several nucleotides and amino acids with distinct distributions across the three study groups, although no obvious clustering of NS5B sequences was observed based on HIV co-infection or CD4 cell count. Polymorphisms at amino acid positions associated with resistance to dasabuvir and sofosbuvir were limited, although the Q309R variant associated with ribavirin resistance was present in 12 individuals with HCV mono-infection, 8 HIV/HCV co-infected individuals with CD4 <350 cells/mm3, and 12 HIV/HCV co-infected individuals with CD4 ≥350 cells/mm3. Previously reported fitness altering mutations were rare. CD8+ T cell responses against the human leukocyte antigen (HLA) B57-restricted epitopes NS5B2629-2637 and NS5B2936-2944 are critical for HCV control and were completely conserved in 44 (51.8%) and 70 (82.4%) study participants. These data demonstrate extensive variation across the NS5B gene. Genotypic variation may have a profound impact on HCV replication and pathogenesis and deserves careful evaluation.

HIV-1 pol gene diversity and molecular dating of subtype C from Sri Lanka.

BackgroundThe first case of HIV infection in Sri Lanka was reported in 1987 and at the end of 2018 there were 3500 people living with HIV. There have been commendable efforts made towards the detection, treatment, and prevention of HIV in the country. Even though the genetic diversity of HIV has been shown to affect the parameters ranging from detection to vaccine development, there is no data available with respect to the molecular epidemiology of HIV-1 in Sri Lanka.MethodsIn this report we have performed the ancillary analysis of pol gene region sequences (n = 85) obtained primarily for the purpose of HIV-1 drug resistance genotyping. Briefly, dried blood spot specimens (DBS) collected from HIV-1 infected individuals between December 2015 and August 2018 were subjected to pol gene amplification and sequencing. These pol gene sequences were used to interpret the drug resistance mutation profiles. Further, sequences were subjected to HIV-1 subtyping using REGA 3.0, COMET, jPHMM and, RIP online subtyping tools. Moreover, Bayesian phylogenetic analysis was employed to estimate the evolutionary history of HIV-1 subtype C in Sri Lanka.ResultsOur analysis revealed that the majority (51.8%) of pol gene sequences were subtype C. Other than subtype C, there were sequences categorized as subtypes A1, B, D and G. In addition to pure subtypes there were sequences which were observed to be circulating recombinant forms (CRFs) and a few of the recombinants were identified as potential unique recombinants (URFs). We also observed the presence of drug resistance mutations in 56 (65.9%) out of 85 sequences. Estimates of the Bayesian evolutionary analysis suggested that the HIV-1 subtype C was introduced to Sri Lanka during the early 1970s (1972.8).ConclusionThe findings presented here indicate the presence of multiple HIV-1 subtypes and the prevalence of drug resistance mutations in Sri Lanka. The majority of the sequences were subtype C, having their most recent common ancestor traced back to the early 1970s. Continuous molecular surveillance of HIV-1 molecular epidemiology will be crucial to keep track of drug resistance, genetic diversity, and evolutionary history of HIV-1 in Sri Lanka.

Challenges of scale-up to dolutegravir-based regimens in sub-Saharan Africa.

Evaluate the potential effectiveness of the implementation of dolutegravir (DTG)-based regimens in patients on failing current antiretroviral treatment (ART) given the high levels of nucleoside reverse transcriptase inhibitor (NRTI) resistance in Togo. Patients on ART attending health facilities for routine follow-up visits and for whom HIV viral load test was performed were consecutively included. Protease, reverse transcriptase and integrase fragments were sequenced and analyzed for presence of drug resistance mutations for patients with viral load more than 1000 copies/ml. Among 1681 patients, 320 (19.04%) had viral load more than 1000 copies/ml and 200 were tested for drug resistance mutations. Reverse transcriptase gene was successfully sequenced for 181/200 (90.5%) patients; 140/181 (77.4%) were resistant to NRTIs and non-NRTIs, 4/181 (2.2%) to NRTIs only and 18/181 (9.9%) to non-NRTIs only. Many viral strains accumulated mutations predicting resistance to NRTIs recommended in first and second-line DTG-based ART regimens. ART switch to a DTG-based regimen after viral load testing (viral load >1000 copies/ml) or blind switch without prior viral load testing to a new DTG-based first line, estimated 31% and 47.6% of patients to be potentially on functional DTG monotherapy respectively. Overall, our results predict that, at the scale of sub-Saharan Africa a significant proportion of patients could be on functional monotherapy. To achieve the third 90 of UNAIDS objectives, implementation of DTG-based regimens should be accompanied with an accelerated scaling up of access to viral load. Studies designed to quantify the implications of use of suboptimal DTG-based regimens are also needed.

Genetic characterization of HIV-1 epidemic in Anhui Province, China

BackgroundAnhui Province in China is facing a severe HIV epidemic with an increasing number of newly diagnosed cases.MethodsIn this study, HIV genetic characteristics in the province were investigated. Newly reported HIV-positive individuals from 15 districts of Anhui Province were enrolled and interviewed. Total viral RNA was extracted from plasma isolated from blood samples. We amplified and sequenced an HIV pol fragment of the 1062 bp. The sequences were used for determination of HIV subtypes and the presence of drug resistance mutations. Transmission networks were constructed to explore possible relationships. And all of assembled partial pol genes were submitted to the Stanford HIV Drug Resistance Database website to find the transmitted drug resistance.ResultsPartial pol gene sequences were obtained from 486 cases. The results showed that MSM was the most dominant transmission route (253, 52.06%), followed by heterosexual transmission (210, 43.21%) and blood-borne transmission (1, 0.21%). Many subtypes were identified, including CRF01_AE (226, 46.50%), CRF07_BC (151, 31.07%), subtype B (28, 5.76%), CRF08_BC (20, 4.12%), CRF55_01B (15, 3.09%), CRF68_01B (7, 1.44%), CRF67_01B (3, 0.62%), CRF57_BC (2, 0.41%), CRF59_01B (2, 0.41%), CRF79_0107 (2, 0.41%), subtype C (2, 0.41%), CRF64_BC (1, 0.21%), and circulating recombinant forms (URFs) (27, 5.55%). Four transmission subnetworks containing high transmission risk individuals (with degree ≥4) were identified based on CRF01_AE and CRF07_BC sequences, including two CRF01_AE transmission subnetworks constituted by elderly people with average ages of 67.9 and 61.5 years. Infection occurred most likely through heterosexual transmission, while the other two CRF07_BC transmission subnetworks consist mainly of MSMs with average ages of 31.73 and 34.15. The level of HIV-transmitted drug resistance is 3.09%.ConclusionsThe simultaneous spread of multiple HIV subtypes in Anhui province underscores that close surveillance of the local HIV epidemic is necessary. Furthermore, the elderly people were frequently involved, arguing for behaviour intervention in this specific population besides the MSM risk group.

Improvement in detecting cytomegalovirus drug resistance mutations in solid organ transplant recipients with suspected resistance using next generation sequencing.

ObjetivesThe aim of this study was to identify CMV drug resistance mutations (DRM) in solid organ transplant (SOT) recipients with suspected resistance comparing next-generation sequencing (NGS) with Sanger sequencing and assessing risk factors and the clinical impact of resistance.MethodsUsing Sanger sequencing as the reference method, we prospectively assessed the ability of NGS to detect CMV DRM in the UL97 and UL54 genes in a nationwide observational study from September 2013 to August 2016.ResultsAmong 44 patients recruited, 14 DRM were detected by Sanger in 12 patients (27%) and 20 DRM were detected by NGS, in 16 (36%). NGS confirmed all the DRM detected by Sanger. The additional six mutations detected by NGS were present in <20% of the sequenced population, being located in the UL97 gene and conferring high-level resistance to ganciclovir. The presence of DRM by NGS was associated with lung transplantation (p = 0.050), the administration of prophylaxis (p = 0.039), a higher mean time between transplantation and suspicion of resistance (p = 0.038) and longer antiviral treatment duration before suspicion (p = 0.024). However, the latter was the only factor independently associated with the presence of DRM by NGS in the multivariate analysis (OR 2.24, 95% CI 1.03 to 4.87).ConclusionsNGS showed a higher yield than Sanger sequencing for detecting CMV resistance mutations in SOT recipients. The presence of DRM detected by NGS was independently associated with longer antiviral treatment.

Frequency and patterns of second-line resistance conferring mutations among MDR-TB isolates resistant to a second-line drug from eSwatini, Somalia and Uganda (2014\u20132016)

BackgroundPulmonary tuberculosis is a leading cause of morbidity and mortality in developing countries. Drug resistance, a huge problem in this contagious disease, is driven by point mutations in the Mycobacterium tuberculosis genome however, their frequencies vary geographically and this affects applicability of molecular diagnostics for rapid detection of resistance. Here, we report the frequency and patterns of mutations associated with resistance to second-line anti-TB drugs in multidrug-resistant (MDR) M. tuberculosis isolates from eSwatini, Somalia and Uganda that were resistant to a second-line anti-TB drug.MethodsThe quinolone resistance determining region (QRDR) of gyrA/gyrB genes and the drug resistance associated fragment of rrs gene from 80 isolates were sequenced and investigated for presence of drug resistance mutations. Of the 80 isolates, 40 were MDR, of which 28 (70%) were resistant to a second-line anti-TB injectable drug, 18 (45%) were levofloxacin resistant while 12 (30%) were extensively drug resistant (XDR). The remaining 40 isolates were susceptible to anti-TB drugs. MIRU-VNTR analysis was performed for M/XDR isolates.ResultsWe successfully sub-cultured 38 of the 40 M/XDR isolates. The gyrA resistance mutations (Gly88Ala/Cys/Ala, Ala90Val, Ser91Pro, Asp94Gly/Asn) and gyrB resistance mutations (Asp500His, Asn538Asp) were detected in 72.2% (13/18) and 22.2% (4/18) of the MDR and levofloxacin resistant isolates, respectively. Overall, drug resistance mutations in gyrA/gyrB QRDRs occurred in 77.8% (14/18) of the MDR and levofloxacin resistant isolates. Furthermore, drug resistance mutations a1401g and g1484 t in rrs occurred in 64.3% (18/28) of the MDR isolates resistant to a second-line anti-TB injectable drug. Drug resistance mutations were not detected in drug susceptible isolates.ConclusionsThe frequency of resistance mutations to second-line anti-TB drugs in MDR-TB isolates resistant to second line anti-TB drugs from eSwatini, Somalia and Uganda is high, implying that rapid molecular tests are useful in detecting second-line anti-TB drug resistance in those countries. Relatedly, the frequency of fluoroquinolone resistance mutations in gyrB/QRDR is high relative to global estimates, and they occurred independently of gyrA/QRDR mutations implying that their absence in panels of molecular tests for detecting fluoroquinolone resistance may yield false negative results in our setting.

PREVALENCE AND STRUCTURE OF HIV-1 DRUG RESISTANCE AMONG TREATMENT NAÏVE PATIENTS SINCE THE INTRODUCTION OF ANTIRETROVIRAL THERAPY IN THE RUSSIAN FEDERATION

Aim:to analyze the prevalence, structure of drug resistance and drug resistance mutations in the protease and reverse transcriptase genes of HIV-1 among treatment naïve patients.Materials and methods.We analyzed protease and reverse transcriptase sequences from 1560 treatment naïve HIV-infected patients from all Federal Districts of the Russian Federation with the first positive immune blot during 1998–2017. Sequences were analyzed for the presence of drug resistance mutations and predicted drug resistance to antiretroviral drugs using two algorithms — Stanford HIVDR Database (HIVdb) and the 2009 SDRM list (CPR).Results.The prevalence of drug resistance mutations was 11,1%. More often the prevalence of drug resistance was found for non-nucleoside reverse transcriptase inhibitor drugs (rilpivirine, nevirapine, efavirenz). The prevalence of transmitted drug resistance associated with mutations from the SDRM list was 5,3%, which is classified by the WHO as a moderate level. However, it should be noted that since the large-scale use of antiretroviral drugs in the Russian Federation, there has been a trend towards a gradual increase in the level of the transmitted drug resistance, and in 2016 it has already reached 6,1%.Conclusion.The results demonstrate the need for regular surveillance of the prevalence of HIV drug resistance to antiretroviral drugs among treatment naïve patients in the Russian Federation.

HIV transmission in discordant couples in Africa in the context of antiretroviral therapy availability.

The study aims to understand the basis of continued HIV-1 transmission in Zambian and Rwandan HIV-1-discordant couples in the context of antiretroviral therapy (ART). We identified nine Zambian and seven Rwandan acutely infected, epidemiologically-linked couples from government couples' voluntary counseling and testing (CVCT) clinics where transmitting partners reported being on ART near the time of transmission. We quantified viral load and plasma antiretroviral drug concentrations near the time of transmission and used these as surrogate measures for adherence. We also sequenced the polymerase gene from both donor and recipient partners to determine the presence of drug resistance mutations (DRMs). In Zambia, all transmitting partners had detectable viral loads, and 8/9 were not on therapeutic antiretroviral regimens. In the remaining couple, despite being on a therapeutic regimen, DRMs were present and transmitted. In Rwanda, although six of seven transmitting partners had detectable viral loads, therapeutic levels of antiretroviral drugs were detected in four of seven, but were accompanied by DRMs. In the remaining three couples, either no antiretrovirals or subtherapeutic regimens were detected. A reduction of ART effectiveness in nontrial settings was associated with lack of antiretrovirals in plasma and detectable viral load, and also drug resistance. In Zambia, where CVCT is not widely implemented, inconsistent adherence was high in couples unaware of their HIV discordance. In Rwanda, where CVCT is deployed country-wide, virologic failure was associated with drug resistance and subsequent transmission. Together, these findings suggest that increasing ART availability in resource-limited settings without risk reduction strategies that promote adherence may not be sufficient to control the HIV epidemic in the post-ART era.

Nationwide Estimates of Viral Load Suppression and Acquired HIV Drug Resistance in Cameroon

BackgroundPopulation-based studies to estimate viral load (VL) suppression and rate of acquired HIV drug resistance (ADR) are essential in sub-Saharan Africa. We conducted the first nationally representative study estimating VL suppression and ADR in Cameroon. MethodsEligible participants were patients on antiretroviral therapy (ART) for 12 to 24 months (ART 12–24) or 48 to 60 months (ART 48–60). ART 12–24 participants were recruited from 24 randomly selected clinics in both urban and rural regions. ART 48–60 participants were recruited from 7 urban clinics. Recruitment occurred from February to August 2015. Dried blood spots (DBSs) and plasma specimens were collected and tested for HIV-1 RNA level and presence of drug resistance mutations (DRM) when VL ≥1000 copies/ml. ResultsOverall, 1064 ART 12–24 and 388 ART 48–60 participants were recruited. Viral suppression in the ART 12–24 group was 72.1% (95% CI: 66.3–77.2) overall, 75.0% (65.2–82.7) in urban sites, and 67.7% (58.3–75.8) in rural sites. In the ART 48–60 group, viral suppression was 67.7% (55.8–77.7). Overall, HIV drug resistance (HIVDR) was 17.7% (15.1–20.6) and 28.3% (17.4–42.5) in the ART 12–24 and ART 48–60 groups, respectively. However, among patients with VL ≥1000 copies/ml, HIVDR was identified in 63.3% (52.0–73.3) of ART 12–24 patients, and in 87.7% (67.4–96.1) of ART 48–60 patients. ConclusionsResults of this first nationwide study indicate alarming levels of virological failure and ADR in Cameroon. Better ART management is urgently needed and should focus on improving ART adherence, availability of VL monitoring, and more timely switches to second-line ART.

Molecular epidemiology of tuberculosis in Tasmania and genomic characterisation of its first known multi-drug resistant case.

BackgroundThe origin and spread of tuberculosis (TB) in Tasmania and the types of strains of Mycobacterium tuberculosis complex (MTBC) present in the population are largely unknown.ObjectiveThe aim of this study was to perform the first genomic analysis of MTBC isolates from Tasmania to better understand the epidemiology of TB in the state.MethodsWhole-genome sequencing was performed on cultured isolates of MTBC collected from 2014–2016. Single-locus variant analysis was applied to determine the phylogeny of the isolates and the presence of drug-resistance mutations. The genomic data were then cross-referenced against public health surveillance records on each of the cases.ResultsWe determined that 83.3% of TB cases in Tasmania from 2014–2016 occurred in non-Australian born individuals. Two possible TB clusters were identified based on single locus variant analysis, one from November-December 2014 (n = 2), with the second from May-August 2015 (n = 4). We report here the first known isolate of multi-drug resistant (MDR) M. tuberculosis in Tasmania from 2016 for which we established its drug resistance mutations and potential overseas origin. In addition, we characterised a case of M. bovis TB in a Tasmanian-born person who presented in 2014, approximately 40 years after the last confirmed case in the state’s bovids.ConclusionsTB in Tasmania is predominantly of overseas origin with genotypically-unique drug-susceptible isolates of M. tuberculosis. However, the state also exhibits features of TB that are observed in other jurisdictions, namely, the clustering of cases, and drug resistance. Early detection of TB and contact tracing, particularly of overseas-born cases, coordinated with rapid laboratory drug-susceptibility testing and molecular typing, will be essential for Tasmania to reach the World Health Organisation’s TB eradication goals for low-incidence settings.

HIV Antiretroviral Resistance and Transmission in Mother–Infant Pairs Enrolled in a Large Perinatal Study

BackgroundDetection of antiretroviral (ARV) resistance in HIV-infected individuals is not uncommon and may be particularly problematic in HIV-infected pregnant women as it can lead to infant infection with resistant strains. To better evaluate the effect of drug resistance mutations (DRMs) on HIV mother-to-child transmission (MTCT), we determined the prevalence of DRMs in a subset of mother–infant pairs enrolled in a multi-center trial of infant prophylaxis among women not receiving ARVs during the current pregnancy.MethodsA case–control design of 1:4 (1 transmitter to 4 nontransmitters) was utilized to evaluate ARV resistance as a predictor of HIV MTCT in specimens obtained from mother–infant pairs. Secondary objectives included identification of potential risk factors associated with the presence of DRMs. Viroseq HIV-1 Genotyping System was performed on mother–infant specimens to assess for mutations that might result in a substantial reduction in drug susceptibility and clinical outcome, as determined by the Stanford HIV Drug Resistance Database.ResultsOne hundred and forty infants were infected. Of these, 123 HIV infected mother–infant pairs and 483 of 560 women who did not transmit HIV had amplifiable HIV nucleic acid enabling ARV resistance testing. A wide variety of DRMs were detected (Figure 1). Sixty (10%) of 606 women had clinically relevant DRMs; 12 (2%) had DRMs against more than 1 ARV class. Among 123 HIV− infected infants, 13 (11%) had clinically relevant DRMs with 3 (2%) harboring DRMs against more than 1 ARV class. Of 13 infants with DRMs, 10 (77%) were infected in utero. In univariate and multivariate analyses, DRMs in mothers were not associated with increased risk of HIV MTCT (AOR 0.79, 95% CI 0.38–1.5). Log HIV viral load was the only predictor of MTCT (OR 1.4, 95% CI 1.2−1.6). The presence of DRMs in mothers who transmitted was strongly associated with the presence of DRMs in infants (P < 0.001).ConclusionIn infected pregnant women without ARV exposure during their current gestation, the presence of pre-existing DRMs with a wide diversity was noted. DRMs do not increase the risk of HIV MTCT. However, if women with DRMs are not virologically suppressed they are likely to transmit resistant mutations even without selective ARV pressure, thus complicating treatment options.Disclosures All authors: No reported disclosures.