Browsing by Author "Sloan, Derek J."

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    Decreased Dolutegravir and Efavirenz Concentrations With Preserved Virological Suppression in Patients With Tuberculosis and Human Immunodeficiency Virus Receiving High-Dose Rifampicin
    (Clinical Infectious Diseases, 2022) Sekaggya-Wiltshire, Christine; Nabisere, Ruth; Musaazi, Joseph; Otaalo, Brian; Aber, Florence; Alinaitwe, Lucy; Nampala, Juliet; Najjemba, Letisha; Buzibye, Allan; Omali, Denis; Gausi, Kamunkhwala; Kengo, Allan; Lamorde, Mohammed; Aarnoutse, Rob; Denti, Paolo; Dooley, Kelly E.; Sloan, Derek J.
    Higher doses of rifampicin may improve treatment outcomes and reduce the duration of tuberculosis (TB) therapy. However, drug–drug interactions with antiretroviral therapy (ART) and safety in people with human immunodeficiency virus (HIV) have not been evaluated. Methods. This was a randomized, open-label trial where newly diagnosed TB patients were randomized to higher (35 mg/kg) or standard (10 mg/kg) daily-dose rifampicin. ART treatment–naive patients were randomized to dolutegravir- or efavirenz-based ART. At week 6, trough dolutegravir or mid-dose efavirenz plasma concentrations were assayed. HIV viral load was measured at week 24. Results. Among 128 patients randomized, the median CD4 count was 191 cells/mm3. The geometric mean ratio (GMR) for trough dolutegravir concentrations on higher- vs standard-dose rifampicin was 0.57 (95% confidence interval [CI], .34–.97; P =.039) and the GMR for mid-dose efavirenz was 0.63 (95% CI, .38–1.07; P= .083). There was no significant difference in attainment of targets for dolutegravir trough or efavirenz mid-dose concentrations between rifampicin doses. The incidence of HIV treatment failure at week 24 was similar between rifampicin doses (14.9% vs 14.0%, P= .901), as was the incidence of drug-related grade 3–4 adverse events (9.8% vs 6%). At week 8, fewer patients remained sputum culture positive on higherdose rifampicin (18.6% vs 37.0%, P =.063). Conclusions. Compared with standard-dose rifampicin, high-dose rifampicin reduced dolutegravir and efavirenz exposures, but HIV suppression was similar across treatment arms. Higher-dose rifampicin was well tolerated among people with HIV and associated with a trend toward faster sputum culture conversion.
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    Pan-Resistome Characterization of Uropathogenic Escherichia coli and Klebsiella pneumoniae Strains Circulating in Uganda and Kenya, Isolated from 2017–2018
    (Antibiotics, 2021) Gonzales Decano, Arun; Pettigrew, Kerry; Sabiiti, Wilber; Sloan, Derek J.; Neema, Stella; Bazira, Joel; Kiiru, John; Onyango, Hellen; Asiimwe, Benon; Holden, Matthew T. G.
    Urinary tract infection (UTI) develops after a pathogen adheres to the inner lining of the urinary tract. Cases of UTIs are predominantly caused by several Gram-negative bacteria and account for high morbidity in the clinical and community settings. Of greater concern are the strains carrying antimicrobial resistance (AMR)-conferring genes. The gravity of a UTI is also determined by a spectrum of other virulence factors. This study represents a pilot project to investigate the burden of AMR among uropathogens in East Africa. We examined bacterial samples isolated in 2017–2018 from in- and out-patients in Kenya (KY) and Uganda (UG) that presented with clinical symptoms of UTI. We reconstructed the evolutionary history of the strains, investigated their population structure, and performed comparative analysis their pangenome contents. We found 55 Escherichia coli and 19 Klebsiella pneumoniae strains confirmed uropathogenic following screening for the prevalence of UTI virulence genes including fimH, iutA, feoA/B/C, mrkD, and foc. We identified 18 different sequence types in E. coli population while all K. pneumoniae strains belong to ST11. The most prevalent E. coli sequence types were ST131 (26%), ST335/1193 (10%), and ST10 (6%). Diverse plasmid types were observed in both collections such as Incompatibility (IncF/IncH/IncQ1/IncX4) and Col groups. Pangenome analysis of each set revealed a total of 2862 and 3464 genes comprised the core genome of E. coli and K. pneumoniae population, respectively. Among these are acquired AMR determinants including fluoroquinolone resistance-conferring genes aac(3)-Ib-cr and other significant genes: aad, tet, sul1, sul2, and cat, which are associated with aminoglycoside, tetracycline, sulfonamide, and chloramphenicol resistance, respectively. Accessory genomes of both species collections were detected several -lactamase genes, blaCTX-M, blaTEM and blaOXA, or blaNDM. Overall, 93% are multi-drug resistant in the E. coli collection while 100% of the K. pneumoniae strains contained genes that are associated with resistance to three or more antibiotic classes. Our findings illustrate the abundant acquired resistome and virulome repertoire in uropathogenic E. coli and K. pneumoniae, which are mainly disseminated via clonal and horizontal transfer, circulating in the East African region. We further demonstrate here that routine genomic surveillance is necessary for high-resolution bacterial epidemiology of these important AMR pathogens.