Immediate pools of malaria infections at diagnosis combined with targeted deep sequencing accurately quantifies frequency of drug resistance mutations

Antimalarial resistance surveillance in sub-Saharan Africa is often constrained by logistical and financial challenges limiting its breadth and frequency. At two sites in Ghana, we have piloted a streamlined sample pooling process created immediately by sequential addition of positive malaria cases at the time of diagnostic testing. This streamlined process involving a single tube minimized clinical and laboratory work and provided accurate frequencies of all known drug resistance mutations after high-throughput targeted sequencing using molecular inversion probes. Our study validates this method as a cost-efficient, accurate and highly-scalable approach for drug resistance mutation monitoring that can potentially be applied to other infectious diseases such as tuberculosis.

Ferroptosis-Related Genes in Lung Adenocarcinoma: Prognostic Signature and Immune, Drug Resistance, Mutation Analysis

Graphical AbstractFerroptosis genes in lung adenocarcinoma.

Macrolide Susceptibility and Molecular Characteristics of Bordetella Pertussis

ObjectiveTo compare the macrolide resistance and molecular characteristics of clinical isolated Bordetella pertussis, and explore the relationship between the macrolide-resistance and genotypes. MethodsErythromycin、azithromycin and clarithromycin susceptibility of clinical isolates during 2018-2020 was determined by E-test. The A2047G of the 23S rRNA genes was sequenced for drug-resistance mutation. Multilocus antigen sequence typing (MAST)、Multiple Locus Variable-number tandem repeat Analysis (MLVA) and Pulsed field gel electrophoresis (PFGE) methods were employed to do molecular typing for the strains. Results58 strains were isolated in this study, 46 of them were macrolide-resistant and 12 sensitive. All macrolide-resistant strains carried a genetic mutation at the A2047G site, genotype was prn1/ptxP1/ptxA1/fim3-1/fim2-1, the MLVA types were identified as MT195、MT55 and MT104, PFGE profiles were classified into BPSR23 and BpFINR9 types. However, no mutations were found in all macrolide-sensitive strains whose genotypes were (prn9 or prn2)/ptxP1/ptxA1/fim3-1/fim2-1 and MT27, and PFGE classified other profiles. ConclusionsThe clinical isolated Bordetella pertussis has serious resistance to erythromycin and began to spread to other macrolides. There were differences between macrolide-resistant and -sensitive Bordetella pertussis in genotypes. The acquisition of macrolide resistance may be associated with change of specific molecular types.

Accumulation of HIV-1 Drug Resistance Mutations and Methamphetamine Use

Background: Antiretroviral therapy (ART) non-adherence and methamphetamine use are associated with higher HIV drug resistance prevalence. How they affect drug resistance mutation accumulation is less studied. Objective: We assessed factors associated with drug resistance mutation accumulation. Methods: We evaluated HIV chronically-infected patients from a clinic-based research cohort on first-line ART regimens with genotype results within 30 days of baseline. Methamphetamine use and ART adherence were self-reported at each study visit. High ART adherence was defined as 0-5% missed doses in the prior 30 days. Results: One-hundred twenty-five patients contributed 496 study visits. At baseline, 81% of patients reported high ART adherence; 90% reported no methamphetamine use in the prior 4 months, 8% used monthly or less and 2% used daily or weekly. Methamphetamine users and non-users had similarly high ART adherence (p=0.93). Adjusted incidence rate ratio (aIRR) of drug resistance mutations accumulation was 2.04 (95% CI 0.64, 6.46) for daily/weekly users and 1.71 (95% CI 0.66, 4.42) for patients with monthly or less users, compared to non-users. aIRR was 0.71 (95% CI 0.44, 1.15) with >5-10% missed ART doses and 1.21 (95% CI 0.80, 1.83) with >10% missed doses compared to 0-5% missed doses. Conclusions: We found no strong evidence for the effect of methamphetamine use and ART adherence on drug resistance mutation accumulation. Research cohort patients may have been more engaged in care and treatment adherence than non-cohort patients. Our findings suggest methamphetamine use might not lead to treatment failure among HIV patients who are otherwise engaged in care.

Transmitted HIV drug resistance and subtype patterns among blood donors in Poland

Surveillance on the HIV molecular variability, risk of drug resistance transmission and evolution of novel viral variants among blood donors remains an understudied aspect of hemovigilance. This nationwide study analyses patterns of HIV diversity and transmitted resistance mutations. Study included 185 samples from the first time and repeat blood donors with HIV infection identified by molecular assay. HIV protease, reverse transcriptase and integrase were sequenced using population methods. Drug resistance mutation (DRM) patterns were analyzed based on the Stanford Interpretation Algorithm and standardized lists of transmitted mutations. Phylogeny was used to investigate subtyping, clustering and recombination patterns. HIV-1 subtype B (89.2%) followed by subtype A6 (7.6%) were predominant, while in three (1.6%) cases, novel recombinant B/A6 variants were identified. Non-B variants were more common among repeat donors (14.5%) compared to the first time ones (1.8%), p = 0.011, with higher frequency (9.9%) of A6 variant in the repeat donor group, p = 0.04. Major NRTI DRMs were observed in 3.8%, NNRTI and PI in 0.6% and INSTI 1.1% of cases. Additionally, E157Q polymorphism was observed in 9.8% and L74I in 11.5% of integrase sequences. Transmission of drug resistance among blood donors remains infrequent. Subtype patters increase in complexity with emergence of novel intersubtype A6B recombinants.

Virological failure and antiretroviral resistance among HIV-infected children after five years follow-up in the ANRS 12225-PEDIACAM cohort in Cameroon

Objective In the present study, we aimed to evaluate the virological failure (VF) and drug resistance among treated HIV-infected children after five years follow-up in the ANRS-Pediacam cohort in Cameroon. Methods From November 2007 to October 2011, HIV-infected children born to HIV-infected mothers were included in the ANRS-PEDIACAM study and followed-up for more than 5 years. Plasma viral load (VL) was measured at each visit (every three months until month 24 and every 6 months thereafter). VF was the main outcome and HIV drug resistance test was performed using the ANRS procedures and algorithm. Results Data from 155 children were analyzed. The median age at combination antiretroviral therapy (cART) initiation was 4.2 months (interquartile range (IQR): 3.2–5.8), with 103 (66.5%) children taking LPV/r-containing regimen and 51 (32.9%) children taking NVP. After five years follow-up, 63 (40.6%; CI: 32.9–48.8) children experienced VF. The median duration between cART initiation and VF was 22.1 months (IQR: 11.9–37.1) with a median VL of 4.8 log10 (IQR: 4.0–5.5). Among the 57 children with HIV drug resistance results, 40 (70.2%) had at least one drug resistance mutation. The highest resistance rates (30.4–66.1%) were obtained with Lamivudine; Efavirenz; Nevirapine and Rilpivirine. Conclusions These results show high resistance to NNRTI and emphasize the need of VL and resistance tests for optimal follow-up of HIV-infected people especially children.

Short Communication: Integrase Strand Transfer Inhibitors Drug Resistance Mutations in Puerto Rico HIV-Positive Individuals

The HIV-1 integrase viral protein is responsible for incorporating the viral DNA into the genomic DNA. The inhibition of viral integration into host cell DNA is part of recent therapeutic procedures. Combination therapy with protease and reverse transcriptase inhibitors has demonstrated good synergistic results in reducing viral replication. The purpose of this study is to assess the occurrence of integrase drug resistance mutations from the period comprising 2013 through 2018 in Puerto Rico (PR). We analyzed 131 nucleotide sequences available in our HIV genotyping database, and we performed drug resistance mutation analyses using the Stanford HIV Drug Resistance Database. Twenty-one sequences (16.03%) harbored major or resistance-associated mutations. We identified the Q148HKR, G140S, Y143R, N155H, S147G, and E138EA major drug resistance mutations and the D232DN, T97TA, E157Q, G163GART accessory mutations. We detected high-level drug resistance to Elvitegravir and Raltegravir (76.19% and 85.71%). Moreover, we identified sequences harboring drug resistance mutations that could provide resistance to Dolutegravir. The transmission of strains with integrase antiretroviral resistance has been previously documented in treatment naïve patients. Given the increase of patients treated with integrase inhibitors, surveillance of drug resistance mutations is an essential aspect of PR’s clinical management of HIV infection.

Drug resistance gene mutations and treatment outcomes in MDR-TB: A prospective study in Eastern China

Background Multidrug-resistant tuberculosis (MDR-TB) poses a serious challenge to TB control. It is of great value to search for drug resistance mutation sites and explore the roles that they play in the diagnosis and prognosis of MDR-TB. Methods We consecutively enrolled MDR-TB patients from five cities in Jiangsu Province, China, between January 2013 and December 2014. Drug susceptibility tests of rifampin, isoniazid, ofloxacin, and kanamycin were routinely performed by proportion methods on Lowenstein–Jensen (LJ) medium. Drug resistance-related genes were sequenced, and the consistency of genetic mutations and phenotypic resistance was compared. The association between mutations and treatment outcomes was expressed as odds ratios (ORs) and 95% confidence intervals (CIs). Results Among 87 MDR-TB patients, 71 with treatment outcomes were involved in the analysis. The proportion of successful treatment was 50.7% (36/71). The rpoB gene exhibited the highest mutation rate (93.0%) followed by katG (70.4%), pncA (33.8%), gyrA (29.6%), eis (15.5%), rrs (12.7%), gyrB (9.9%) and rpsA (4.2%). Multivariable analysis demonstrated that patients with pncA gene mutations (adjusted OR: 19.69; 95% CI: 2.43–159.33), advanced age (adjusted OR: 13.53; 95% CI: 1.46–124.95), and nonstandard treatment (adjusted OR: 7.72; 95% CI: 1.35–44.35) had a significantly higher risk of poor treatment outcomes. Conclusions These results suggest that Mycobacterium tuberculosis gene mutations may be related to phenotypic drug susceptibility. The pncA gene mutation along with treatment regimen and age are associated with the treatment outcomes of MDR-TB.