Prevalence Of Drug Resistance Research Articles

Prevalence of acquired and transmitted HIV drug resistance in Iran: a systematic review and meta-analysis.

There is no systematic review on the prevalence of HIV drug resistance (HIVDR) in Iran. We aimed to estimate the prevalence of HIVDR among people living with HIV (PLHIV) in Iran. We assessed HIVDR prevalence in antiretroviral therapy (ART) naïve PLHIV (i.e., those without a history of ART) and PLHIV receiving ART. We systematically searched Scopus, PubMed, Web of Science, Embase, Iranian databases (Iranian Medical Research Information System, Magiran, and Scientific Information Database), the references of studies, and Google Scholar until March 2023. A random-effects model was used to calculate a point estimate and 95% confidence interval (95% CI) for the prevalence of HIVDR in PLHIV. Among 461 potential publications, 22 studies were included in the meta-analysis. The pooled prevalence of acquired HIVDR in PLHIV receiving ART was 34% (95% CI: 19, 50) for nucleoside/nucleotide reverse transcriptase inhibitors (NRTIs), 27% (95% CI: 15, 41) for non-nucleoside reverse transcriptase inhibitors (NNRTIs), and 9% (95% CI: 3, 18) for protease inhibitors (PIs). The pooled prevalence of acquired HIVDR in treatment failure PLHIV was 50% (95% CI: 31, 69) for NRTIs, 49% (95% CI: 29, 69) for NNRTIs, 11% (95% CI: 2, 24) for PIs, and 1% (95% CI: 0, 4) for integrase inhibitors (INIs). The pooled prevalence of transmitted HIVDR in ART-naïve people was 3% (95% CI; 1, 6) for NRTIs, 5% (95% CI: 2, 9) for NNRTIs, and 0 for PIs and INIs. The prevalence of HIVDR was relatively high in both ART-naïve PLHIV and those receiving ART. Without universal pretreatment HIVDR testing and more frequent routine HIV viral load testing among PLHIV who are on ART, the HIVDR prevalence might increase in PLHIV in Iran.

PCR-RFLP study on drug resistance of Haemonchus contortus to benzimidazole in sheep, North region of Iran

Haemonchosis is one of the most important parasitic diseases of the gastrointestinal tract of small ruminants in different parts of Iran and worldwide. While the disease poses major economic problems in the livestock industry, there are many reports on parasites’ resistance to benzimidazoles necessita­ting to study of the level of this drug resistance in pathogens. The aim of this study was to evaluate the drug resistance of Haemonchus contortus to benzimidazole using molecular method in sheep from the North region of Iran. In this study, the resistance to benzimidazole was investigated using the PCR-RFLP method in the nematode Haemonchus contortus from sheep slaughtered in the northern region of Iran (Gilan and Mazandaran provinces). The samples examined in this study were evaluated between April 2020 and September 2021 from a total of 2400 sheep by determining the age groups of <2 years, 2-4 years, and >4 years. Three hundred Haemonchus contortus nematodes were randomly selected and investigated by means of PCR-RFLP and using TaaI endonuclease enzyme (SNP) in the beta-tubulin gene, responsible for drug resistance of Haemonchus contortus to benzimidazole. Haemonchus contortus was found in 66.8% and 60.5% of sheep in Gilan and Mazandaran. The results of the study showed that the drug sensitivity rate was 24% (72/300), the drug resistance rate was 54% (162/300) and 22% (66/300) of the samples had both resistant and sensitive alleles. Presented data showed a high level of prevalence of drug resistance in the nematode Haemonchus contortus in sheep in the northern region of Iran, which requires special attention to control the development of this resistance and the epidemic of haemonchosis in ruminants.

Profiling of antimicrobial resistance (AMR) and multi drug resistance (MDR) of <em>Escherichia coli</em> isolates from livestock, wild animals and an ornamental fish farm in Polgahawela, Sri Lanka

The pattern of antimicrobial resistance (AMR) and the prevalence of multi drug resistance (MDR) of Escherichia coli (E. coli) isolates from livestock, wild animals and an ornamental fish farm were investigated in a selected area in Polgahawela, Sri Lanka. Sampling area of one square Km containing an ornamental fish farm, a broiler farm, cattle, goat, and backyard poultry which are located separately within the sampling area but not in an integrated farming system with its associated wildlife was mapped using GPS. Faecal samples were examined from 89 wild animals (terrestrial and avian species), 28 livestock animals (including poultry) as well as 40 samples from an ornamental fish farm (fish faecal material, pond water and pond sediment). E. coli was isolated using standard methods and AMR profiles were investigated for 12 antimicrobials using Kirby-Bauer disc diffusion method. Sixty nine percent (62/89) of wild animals and 86% (24/28) of livestock samples were positive for E. coli whereas the isolation rate was 17.5% (7/40) in the samples from the ornamental fish farm. A maximum of two randomly selected E. coli isolates from each sample, making a total of 164 isolates were tested for AMR of which 114, 43 and 7 were from wild animals, livestock and the ornamental fish farm, respectively. The E. coli isolates tested against 12 antimicrobials reflected that the proportions of E. coli isolates resistant to at least one antimicrobial were 30%, 63% and 71% in wild animals, livestock and the ornamental fish farm, respectively. Multidrug-resistant E. coli isolates were detected in wild animals, livestock and the samples from ornamental fish farm. Overall, according to the statistical analysis, E. coli isolated from livestock and the ornamental fish farm reflected a significantly higher chance of carrying AMR compared with E. coli from wild animals.

Prevalence of HIV-1 drug resistance among patients with high viral loads while on second-line antiretroviral treatment in Butha-Buthe and Mokhotlong, Lesotho

Prevalence of HIV-1 drug resistance among patients with high viral loads while on second-line antiretroviral treatment in Butha-Buthe and Mokhotlong, Lesotho

Molecular epidemiological characteristics of newly diagnosed HIV-1 cases in Fujian Province in 2020

To investigate the HIV-1 genotype and distribution of newly diagnosed HIV-1 cases in Fujian Province in 2020, so as to provide insights into formulation of the precise AIDS control strategy in the province. Newly diagnosed HIV-1 cases without antiretroviral therapy (excluding AIDS patients) were randomly sampled from each city of Fujian Province in 2020 at a proportion of 50% of the mean number of HIV-infected cases reported across 9 cities of Fujian Province during the past three years. Subjects' demographic and epidemiological data were collected and blood samples were collected. The HIV-1 pol gene was amplified using nested reverse-transcription PCR assay, and the gene sequences were used for HIV-1 genotyping and phylogenetic analysis. The gene sequences were uploaded to the HIV Drug Resistance Database (http://hivdb.stanford.edu) for genotypic drug resistance assays, and the scores and level of HIV drug resistance were estimated using the HIVDB Algorithm version 9.5. A total of 1 043 newly diagnosed HIV-1 cases were reported in Fujian Province in 2020, and 936 gene sequences were successfully obtained following sequencing of blood samples. There were 9 HIV-1 genotypes characterized in blood samples from 936 newly diagnosed HIV-1 cases, with CRF07_BC (52.1%) and CRF01_AE (30.4%) as predominant subtypes, followed by CRF08_BC (4.9%), CRF55_01B (3.0%), subtype C (2.5%), subtype B (2.1%), CRF85_BC (1.7%), CRF59_01B (0.3%) and CRF65_CPX (0.1%), and unidentified subtypes were found in 26 blood samples. HIV-1 drug resistance was detected in 43 out of the 936 newly diagnosed HIV-1 cases, with 4.6% prevalence of HIV-1 drug resistance prior to therapy, and the highest drug resistance was found in the HIV CRF59_01B subtype, followed by in CRF08_BC, B, C, CRF01_AE, CRF07_BC and other subtypes, with a significant difference in the genotype-specific prevalence of HIV-1 drug resistance (χ2 = 45.002, P < 0.05). There was a HIV-1 genotype diversity in Fujian Province in 2020, and emerging recombinant and drug-resistant HIV-1 strains were detected and spread across patients and regions. Monitoring of HIV-1 genotypes is recommended to be reinforced for timely understanding of the transmission and spread of novel recombinant and drug-resistant HIV-1 strains.

Repurposing a human acetyl-CoA carboxylase inhibitor firsocostat to treat fungal candidiasis alone and in combination.

Opportunistic fungal infections, particularly caused by Candida albicans, remain a common cause of high morbidity and mortality in immunocompromised patients. The escalating prevalence of antifungal drug resistance necessitates the immediate exploration of alternative treatment strategies to combat these life-threatening fungal diseases. In this study, we investigated the antifungal efficacy of firsocostat, a human acetyl-CoA carboxylase (ACC) inhibitor, against C. albicans. Firsocostat alone displayed moderate antifungal activity, while combining it with voriconazole, itraconazole, or amphotericin B exhibited synergistic effects across almost all drug-sensitive and drug-resistant C. albicans strains tested. These observed synergies were further validated in two mouse models of oropharyngeal and systemic candidiasis, where the combination therapies demonstrated superior fungicidal effects compared to monotherapy. Moreover, firsocostat was shown to directly bind to C. albicans ACC and inhibit its enzymatic activity. Sequencing spontaneous firsocostat-resistant mutants revealed mutations mapping to C. albicans ACC, confirming that firsocostat has retained its target in C. albicans. Overall, our findings suggest that repurposing firsocostat, either alone or in combination with other antifungal agents, holds promising potential in the development of antifungal drugs and the treatment of candidiasis.

Prevalence of HIV drug resistance among adolescents receiving ART in Cameroon with low- or high-level viraemia.

To characterize HIV drug resistance (HIVDR) below and above the WHO threshold of 1000 copies/mL, considered for the definition of HIV ART failure in resource-limited settings. From a cohort of 280 adolescents (aged 10-19 years) receiving ART for at least 6 months, genotypic resistance testing (GRT) was attempted for two groups of participants: participants with low-level viraemia [LLV; viral load (VL) 200-999 copies/mL] and those in virological failure (VF; confirmed VL ≥1000 copies/mL) using an in-house method. The Stanford HIValg Program was used to identify relevant HIVDR mutations and predict the efficacy of the newly introduced tenofovir-lamivudine-dolutegravir combination. GRT was successfully performed in 54/58 (93.1%) eligible participants, of which 28/31 (90.3%) were in VF and 26/27 (96.3%) had LLV. A high level of resistance was found both in adolescents with LLV and those in VF, with respectively 84.6% (22/26) and 75.0% (21/28) of participants harbouring at least one HIVDR mutation. NRTIs and NNRTIs were the most affected drug classes in both population groups. In contrast, PIs were not significantly affected and dolutegravir was expected to be active for all participants tested. However, for the newly introduced dolutegravir-based combination, functional monotherapy (dolutegravir only) was potentially possible for 22.7% (5/22) of the participants with LLV. Our findings show that the 1000 copies/mL threshold is not an indicator of virological success and we call for a revision of the current WHO definition of VF in resource-limited countries.

Molecular characterization and immune protective efficacy of 3 Eimeria tenella antigens

Avian coccidiosis caused by Eimeria is a serious parasitic disease that poses a threat to the poultry industry. Currently, prevention and treatment mainly rely on the administration of anticoccidials and live oocyst vaccines. However, the prevalence of drug resistance and the inherent limitations of live vaccines have driven the development of novel vaccines. In this study, the surface protein (Et-SAG14), a previously annotated rhoptry protein (Eten5-B), and a gametocyte phosphoglucomutase (Et-PGM1) were characterized and the vaccine potential of the recombinant proteins were evaluated. Et-SAG14 was dispersed in the form of particles in the sporozoite and merozoite stages, whereas Et-PGM1 was distributed in the apical part of the sporozoite and merozoite stages. The previously annotated rhoptry Eten5-B was found not to be located in the rhoptry but distributed in the cytoplasm of sporozoites and merozoites. Immunization with rEten5-B significantly elevated host interferon gamma (IFN-γ) and interleukin 10 (IL-10) transcript levels and exhibited moderate anticoccidial effects with an anticoccidial index (ACI) of 161. Unexpectedly, both recombinant Et-SAG14 and Et-PGM1 immunization significantly reduced host IFN-γ and IL-10 transcription levels, and did not show protection against E. tenella challenge (ACI < 80). These results suggest that the rEten5-B protein can trigger immune protection against E. tenella and may be a potential and effective subunit vaccine for the control of coccidiosis in poultry.

Epidemiological characteristics of HIV transmission in southeastern China from 2015 to 2020 based on HIV molecular network.

HIV/AIDS remains a global public health problem, and understanding the structure of social networks of people living with HIV/AIDS is of great importance to unravel HIV transmission, propose precision control and reduce new infections. This study aimed to investigate the epidemiological characteristics of HIV transmission in Fujian province, southeastern China from 2015 to 2020 based on HIV molecular network. Newly diagnosed, treatment-naive HIV/AIDS patients were randomly sampled from Fujian province in 2015 and 2020. Plasma was sampled for in-house genotyping resistance test, and HIV molecular network was created using the HIV-TRACE tool. Factors affecting the inclusion of variables in the HIV molecular network were identified using univariate and multivariate logistic regression analyses. A total of 1,714 eligible cases were finally recruited, including 806 cases in 2015 and 908 cases in 2020. The dominant HIV subtypes were CRF01_AE (41.7%) and CRF07_BC (38.3%) in 2015 and CRF07_BC (53. 3%) and CRF01_AE (29.1%) in 2020, and the prevalence of HIV drug resistance was 4.2% in 2015 and 5.3% in 2020. Sequences of CRF07_BC formed the largest HIV-1 transmission cluster at a genetic distance threshold of both 1.5 and 0.5%. Univariate and multivariate logistic regression analyses showed that ages of under 20 years and over 60 years, CRF07_BC subtype, Han ethnicity, sampling in 2015, absence of HIV drug resistance, married with spouse, sampling from three cities of Jinjiang, Nanping and Quanzhou resulted in higher proportions of sequences included in the HIV transmission molecular network at a genetic distance threshold of 1.5% (p < 0.05). Our findings unravel the HIV molecular transmission network of newly diagnosed HIV/AIDS patients in Fujian province, southeastern China, which facilitates the understanding of HIV transmission patterns in the province.

High frequency of ofloxacin resistance patterns of Mycobacterium leprae from India: An indication to revisit second line anti-leprosy treatment regimen

Drug resistance in leprosy is an emerging concern, leading to treatment failures, recurrences, and potential spread of resistant Mycobacterium leprae in the community. In this study, we aimed to assess drug resistance prevalence and patterns amongst leprosy patients at a tertiary care referral hospital in India. Mutations in drug resistance determining regions for dapsone, rifampicin, and ofloxacin of the M. leprae genome in DNA extracted from skin biopsies of 136 leprosy patients (treatment-naive=67, with persistent skin lesions=35, with recurrence=34) were analysed by polymerase chain reaction followed by Sanger sequencing. Wild-type strain (Thai-53) was used as a reference strain. Resistance mutations were identified in a total of 23 patients, constituting 16.9% of the cohort. Within this subset of 23 cases, resistance to ofloxacin was observed in 17 individuals (12.5%), while resistance to both dapsone and rifampicin was detected in three patients each (2.2% for both). The occurrence of ofloxacin resistance showed minimal disparity between recurrent and treatment-naive cases, at 17.6% and 16.4%, respectively. Dapsone resistance emerged in two treatment-naive cases and one case with persistent skin lesions. Notably, none of the treatment-naive cases or those with recurrence/relapse exhibited rifampicin resistance. Subsequently, no statistically significant correlation was identified between other clinical variables and the presence of antimicrobial resistance. The occurrence of resistance to the current multidrug therapy regimen (specifically dapsone and rifampicin) and to ofloxacin, a secondary antileprosy medication in M. leprae, represents a concerning scenario. This calls for an expansion towards bactericidal drug options and the establishment of robust surveillance for drug resistance in countries burdened with high leprosy rates. Moreover, the introduction of stringent antimicrobial stewardship initiatives is imperative. As a single centre study, it represents a limited, cross-sectional view of the real situation in the field.

Multiproperty Polyethylenimine-Caged Platinum Nanoclusters Promote Apoptosis of Osteosarcoma Cells via Regulating the BAX-Bcl-2/Caspase-3/PARP Axis.

Osteosarcoma, a prevalent primary bone cancer in children, exhibits a poor prognosis due to the high prevalence of drug resistance. The objective of this study was to investigate the potential of fluorescent ultrafine polyethylenimine-coated caged platinum nanoclusters (PEI-Pt NCs) as an antitumor agent in osteosarcoma. The primary focus of this study involved the utilization of osteosarcoma cells (U2-OS and MG-63) and normal control cells (hBMSC) as the primary subjects of investigation. The capacity of PEI-Pt NCs to enter osteosarcoma cells was observed through the implementation of confocal microscopy. The impact of PEI-Pt NCs on migration and proliferation was assessed through the utilization of various methodologies, including the CCK8 assay, Ki-67 immunofluorescence, clone formation assay, transwell assay, and wound healing assay. Furthermore, the influence of PEI-Pt NCs on apoptosis and its underlying mechanism was explored through the implementation of flow cytometry and Western blotting techniques. The PEI-Pt NCs demonstrated the capability to enter osteosarcoma cells, including the nucleus, while also exhibiting fluorescent labeling properties. Furthermore, the PEI-Pt NCs effectively impeded the migration and proliferation of osteosarcoma cells. Additionally, the PEI-Pt NCs facilitated apoptosis by modulating the BAX-Bcl-2/Caspase 3/PARP axis. The novel nanomaterial PEI-Pt NCs possess diverse advantageous capabilities, including the ability to impede cell proliferation and migration, as well as the capacity to modulate the BAX-Bcl-2/Caspase 3/PARP axis, thereby promoting cell apoptosis. Consequently, this nanomaterial exhibits promising potential in addressing the issue of inadequate platinum-based treatment for osteosarcoma.

Assessment of risk factors associated with multi-drug resistant tuberculosis (MDR-TB) in Gulu regional referral hospital.

Multi-drug resistant tuberculosis (MDR-TB) is increasingly recognized as emerging infectious disease of public health concern. Globally, 206030 people were diagnosed with MDR-TB in 2019, representing a 10% increase from 186883people who had it in 2018. In Uganda, the prevalence of MDR among new TB cases is 4.4% and 17.7% among previously treated TB cases. To determine the risk factors associated with MDR-TB among tuberculosis patients in Gulu regional referral hospital. A cross-sectional analytical study using both quantitative and qualitative methods of data collection and analysis was used. Data was collected from 384 TB patients using data extraction form and 6 Key informant interviews conducted. Analysis using Pearson chi-square test was run. HIV positive patients were 2.6 times more likely to be infected with MDR-TB than HIV negative patients [AOR=2.6: 95% CI 1.34- 5.85: P=0.006]. Previously treated TB patients were 2.8 times more likely to be infected with MDR-TB than newly diagnosed TB patients [AOR=2.8: 95% CI 1.33- 5.85: P=0.006]. Defaulting TB patients were 3.1 times more likely to be infected with MDR-TB than the non-defaulting TB patients [AOR=3.1]. There is high prevalence of drug resistance among patients attending TB treatment at the facility.

Antibacterial and antioxidant activity of compounds from Citrus sinensis peels and in silico molecular docking study

The increasing prevalence of drug resistance, adverse side effects of existing antibiotics, and the resurgence of previously known infections have necessitated the search for new, safe, and effective antimicrobial agents. The peels of Citrus sinensis (300 g) were extracted using maceration and ultrasonic-assisted extraction methods with ethanol, resulting in yields of 20.99 g and 11.5 g (7%, 7.5%), respectively. Silica gel column chromatographic separation of the ethanol extract yielded N-(1,3,4,5-tetrahydroxydecan-2-y1)octanamide (1), decanoic acid (2), β-sitosterol-3-O-β-D-glucopyranoside derivative (3), and (z)-ethyl tetradec-7-enoate (4). GC-MS analysis of the essential oil detected 7 chemical components accounting for 99.84% of the total composition of which limonene was found to be the predominant constituent (87.5%). In vitro antibacterial tests revealed promising zones of inhibition by ethanol extract (12.67±0.58 mm, at 150 mg/mL), compound 4 (15.67±2.88 mm, at 6 mg/mL), and compound 1 (12.00±0.00 mm, at 6 mg/mL) against E. faecalis, S. typhimurium, and P. aeruginosa, respectively, compared to gentamicin (13.00±1.73 mm, 18.00±1.00 mm, and 16.67±1.15 mm, respectively at 10 µg/mL). DPPH radical scavenging activity indicated that compound 1 exhibited an IC50 value of 0.05 mg/mL, compared to ascorbic acid's 0.016 mg/mL. In silico molecular docking studies revealed that compounds 1 and 3 had the lowest scoring poses against E. coli DNA gyrase B enzyme, human peroxiredoxin 5, and S. aureus pyruvate kinase, respectively. These findings support traditional applications of Citrus peels in treating infectious diseases, particularly against Gram-positive strains, and highlight their potential use as antibacterial ingredients in cosmetics.

Prevalence of HIV-1 drug resistance among early diagnosed HIV-infected children enrolled through the national program for prevention of mother-to-child transmission in Southern and Central Highland provinces — Vietnam within 2017–2021

Prevalence of HIV-1 drug resistance among early diagnosed HIV-infected children enrolled through the national program for prevention of mother-to-child transmission in Southern and Central Highland provinces — Vietnam within 2017–2021

Emergence of clinical &lt;i&gt;vanA&lt;/i&gt;-type vancomycin-resistant &lt;i&gt;Staphylococcus aureus&lt;/i&gt; isolates in National Orthopaedic Hospital Dala, Kano, Nigeria

Background: The increasing prevalence of multi drug resistance (MDR) in strains of Staphylococcus aureus is a major challenge in the selection of an appropriate therapeutic agents, especially in persistent orthopaedic infections. This study investigated the patterns of antimicrobial resistance and identified the genetic determinants of resistance in S. aureus isolates from orthopaedic patients.&#x0D; Methodology: This was a descriptive cross-sectional study of hospitalized patients at National Orthopaedic Hospital Dala (NOHD), Kano, Nigeria from whom urine samples, and nasal and wound swabs were collected for isolation of S. aureus. Samples were cultured on standard media and S. aureus isolated and identified using both conventional biochemical tests and a standard rapid diagnostic kit. The antibiotic susceptibility was determined to a panel of 15 antibiotics using the modified Kirby-Bauer disc diffusion method. Vancomycin minimum inhibitory concentration (MIC) of each isolate was determined using vancomycin Epsilon-test strip. mecA and vanA were detected by multiplex polymerase chain reaction (PCR) assay.&#x0D; Results: From the total of 134 samples, S. aureus was isolated from 36 (26.8%); 10 (7.4%) from urine, 13 (9.7%) from nasal swab, and 13 (9.7%) from wound swab. Thirty-four (94.4%) isolates were phenotypically methicillin (cefoxitin) resistant (MRSA), while 2 (5.6%) isolates were methicillin sensitive (MSSA). Phenotypic resistance rate of the S. aureus isolates was highest to gentamicin (94.4%), followed by penicillin (88.8%), cephalosporins and fluoroquinolones (87.4%), while rate was lowest to vancomycin (11.1%, 4/36). Seventeen (47.2%) were MDR, 16 (44.4%) were extensively drug resistant (XDR), and 2 (5.6%) were pan-drug resistant (PDR) S. aureus isolates. The mecA gene was detected in 4 (11.8%) of the 34 phenotypic MRSA isolates and vanA genes in 2 (50.0%) of the 4 phenotypic VRSA isolates.&#x0D; Conclusion: The detection of vanA and mecA in clinical S. aureus isolates in this study is an indication that clinical VRSA has emerged in MRSA population in Nigeria. This emergence can pose a major threat to primary care-givers and a public health challenge among the daily inhabitants of National Orthopaedic Hospital Dala (NOHD), Kano and the community at large.

In vitro model to simulate multiple drugs with distinct elimination half-lives

The prevalence of drug resistance in pathogens such as HIV and selected bacteria has been steadily rising, resulting in an increased need for using multiple agents concurrently. Agents used in these combination therapies may have different elimination half-lives in humans. There is an unmet need for in vitro models to evaluate the efficacy of these combinations to guide early drug development. In order to realistically reflect in vivo conditions, useful in vitro model systems must be capable of simulating multiple pharmacokinetic profiles with distinct elimination half-lives. The goal of this study was to experimentally simulate four pharmacokinetic profiles with distinct elimination half-lives in an in vitro hollow-fibre system. For illustrative purposes, fluctuating exposures of ceftriaxone were simulated with distinct half-lives of 1, 2.5, 8, and 12 hours. A parallel experimental setup was used to independently connect four supplemental reservoirs to a central reservoir. Target maximum concentration was achieved by direct drug dosing into the central reservoir; supplemental reservoirs were also dosed to offset the rapid drug elimination rate from the central reservoir. Serial pharmacokinetic samples were obtained from the central reservoir, assayed by a spectrophotometric method, and characterized by a one-compartment model. The observed maximum concentrations and elimination half-lives were in agreement with the expected values obtained from the mathematical predictions. This in vitro experimental system can be used to evaluate the efficacy of up to four-drug combinations against multidrug-resistant bacteria or HIV-infected mammalian cells. The established framework represents an adaptable tool to advance the field of combination therapy.

Characteristics of genotype, drug resistance, and molecular transmission network among newly diagnosed HIV-1 infections in Shenzhen, China.

The HIV-1 pandemic has persisted for four decades, and poses a major challenge to global public health. Shenzhen, a city with large number of migrant populations in China, is suffering HIV-1 epidemic. It is necessary to continuously conduct the molecular surveillance among newly diagnosed HIV-1 patients in these migrant population. In this study, plasma samples of newly diagnosed and ART-naive HIV-1 infections were collected from Shenzhen city in China. The partial genes of HIV-1 gag and pol were amplified and sequenced for the analysis of genotype, drug resistance, and molecular transmission network. Ninety-one sequences of pol gene were obtained from newly diagnosed HIV-1 infections in Shenzhen, and seven HIV-1 subtypes were revealed in this investigation. Among them, the circulating recombinant form (CRF) 07_BC was the mostly frequent subtype (53.8%, 49/91), followed by CRF01_AE (20.9%, 19/91), CRF55_01B (9.9%, 9/91), unique recombinant forms (URFs) (8.8%, 8/91), B (3.3%, 3/91), CRF59_01B (2.2%, 2/91), and CRF08_BC (1.1%, 1/91). The overall prevalence of pretreatment drug resistance (PDR) was 23.1% (21/91), and 52.38% (11/21) of the PDR was specific for the nonnucleotide reverse transcriptase inhibitors (NNRTIs). Furthermore, a total of 3091 pol gene sequences were used to generate 19 molecular transmission clusters, and then one growing cluster, a new cluster, and a cluster with growth reactivation were identified. The result revealed that more sexual partner, CRF_07BC subtype, and seven amino acid deletions in gag p6 region might be the influencing factors associated with the high risk of transmission behavior. Compared with CRF01_AE subtype, CRF07_BC subtype strains were more likely to form clusters in molecular transmission network. This suggests that long-term surveillance of the HIV-1 molecular transmission should be a critical measure to achieve a precise intervention for controlling the spread of HIV-1 in China.

High-Level Drug-Resistant Mutations among HIV-1 Subtype A6 and CRF02_AG in Kazakhstan.

HIV incidence in Kazakhstan increased by 73% between 2010 and 2020, with an estimated 35,000 people living with HIV (PLHIV) in 2020. The development of antiretroviral drug resistance is a major threat to effective antiretroviral therapy (ART), yet studies on the prevalence of drug resistance in Kazakhstan are sparse. In this study on the molecular epidemiology of HIV in Kazakhstan, we analyzed 968 partial HIV-1 pol sequences that were collected between 2017 and 2020 from PLHIV across all regions of Kazakhstan, covering almost 3% of PLHIV in 2020. Sequences predominantly represented subtypes A6 (57%) and CRF02_AG (41%), with 32% of sequences exhibiting high-level drug resistance. We further identified distinct drug-resistant mutations (DRMs) in the two subtypes: subtype A6 showed a propensity for DRMs A62V, G190S, K101E, and D67N, while CRF02_AG showed a propensity for K103N and V179E. Codon usage analysis revealed that different mutational pathways for the two subtypes may explain the difference in G190S and V179E frequencies. Phylogenetic analysis highlighted differences in the timing and geographic spread of both subtypes within the country, with A62V-harboring subtype A6 sequences clustering on the phylogeny, indicative of sustained transmission of the mutation. Our findings suggest an HIV epidemic characterized by high levels of drug resistance and differential DRM frequencies between subtypes. This emphasizes the importance of drug resistance monitoring within Kazakhstan, together with DRM and subtype screening at diagnosis, to tailor drug regimens and provide effective, virally suppressive ART.

Age and CD4+ T cell counts are inversely associated with HIV drug resistance mutations in treatment naive female sex workers.

The increasing prevalence of human immunodeficiency virus (HIV) drug resistance mutations (HIVDRM) in untreated seropositive persons has consequences for future treatment options. This is extremely important in key populations such as female sex workers (FSWs), where the prevalence of pretreatment drug resistance (PDR) and associated risk factors are unknown. In this study, we analyzed PDR and associated risk factors in recently diagnosed and treatment-naive FSWs in Nairobi, Kenya. In this cross-sectional study, we used 64 HIV-seropositive plasma samples collected from FSWs between November 2020 and April 2021. To identify HIVDRM, the pol gene was amplified and genotyped using sanger sequencing. The effects of age, tropism, CD4+ T cell count, subtype, and location on HIVDRM counts were examined using Poisson regression. Overall, the prevalence of PDR was 35.9% (95% CI: 24.3-48.9), which was strongly influenced by K103N and M184V mutations, which confer resistance to non-nucleoside reverse transcriptase inhibitors (NNRTIs) and nucleoside reverse transcriptase inhibitors (NRTI), respectively. Subtype A1 was predominant followed by subtype D with a notable increase in inter-subtype recombinants. We found statistically significant evidence that age was inversely related to HIVDRM. A FSW who is 1 year older had 12% less HIVDRM (incidence rate ratios [IRR]: 0.88; 95% CI: 0.82-0.95; P < .001), after adjusting for CD4+ T cell count, subtype, location, and tropism. Similarly, an increase in CD4+ T cell count by 1 unit, was associated with 0.4% fewer HIVDRM (IRR: 0.996; 95% CI: 0.994-0.998; P = .001), while controlling for the other variables. HIV-1 tropism was not associated with HIVDRM counts. In conclusion, our findings show a high prevalence of NNRTIs. Lower CD4+ T cell counts and younger age were significant risk factors that influenced HIVDRM loads. This finding underscores the relevance of targeted interventions and the importance of continuing to focus on FSWs as a way of addressing the HIV epidemic.

Concordance between Genotypic and Phenotypic Drug-Resistant Profiles of Shigella Isolates from Taiyuan City, Shanxi Province, China, 2005 to 2016.

Antimicrobial resistance in Shigella spp. is a global public health concern. In this study, the AMR phenotypic profiles of 10 kinds of antibiotics were compared with the genotypic profiles using genomic analysis of 218 Shigella isolates from Taiyuan City, Shanxi Province, China, 2005 to 2016. Core genome Multilocus Sequence Typing (cgMLST) based on the EnteroBase Escherichia/Shigella scheme was used to obtain the genetic relatedness of Shigella isolates. Multiple-drug resistance was observed in 96.79% Shigella spp., and the resistance to antimicrobial agents varied between S. flexneri and S. sonnei. The genotypic results correlated well with the phenotypic profiles with concordance rates of 96.42% and 94.50% in S. flexneri and S. sonnei isolates, respectively, from Taiyuan City, Shanxi Province. The sensitivity and specificity of the genotypic antimicrobial susceptibility testing (AST) were 97.56% and 95.34% for S. flexneri, and 95.65% and 93.31% for S. sonnei isolates, respectively. A discrepancy of genotypic and phenotypic AST results existed in some cephalosporin- and azithromycin-resistant Shigella isolates; there were no clear resistance patterns to predict ciprofloxacin resistance. There were major discrepancies between genotypic and phenotypic AST in the genotypically resistant but phenotypically susceptible isolates. The drug-resistance patterns and essential drug-resistance genes to predict the phenotypic drug-resistant profiles were the discrepancies between S. flexneri and S. sonnei isolates. Phylogenetic analysis showed that isolates of the same cluster but with different antibiotic-resistance gene patterns occurred because of the loss or gain of antibiotic-resistance genes located in the plasmids and multidrug-resistance islands. IMPORTANCE Antimicrobial resistance in Shigella spp. has become a global public health concern. In this study, we identified the antimicrobial susceptibility testing (AST) characteristics based on genomic sequences of 218 Shigella isolates and analyzed the correlation between genotypic and phenotypic antibiotic resistance profiles of Shigella spp., especially for fluoroquinolone, macrolides, and third-generation cephalosporins. Our results show that the genotypic results correlated with the phenotypic profiles with concordance rates of 96.42% and 94.50% in S. flexneri and S. sonnei isolates, respectively. The drug-resistance patterns and essential drug-resistance genes to predict the phenotypic drug-resistant profiles of S. flexneri and S. sonnei isolates in Taiyuan city were distinct. The discrepancy between genotypic and phenotypic AST was considerable in the genotypically resistant but phenotypically susceptible isolates. The information on drug resistance and resistance genes in this study can offer more details on the prevalence of drug resistance of Shigella spp.