Suchergebnisse

We demonstrated that some non-synonymous and synonymous mutations in $\textit{gyrA}$ in $\textit{Mycobacterium tuberculosis}$ result in systematic false-resistance results to fluoroquinolones using the Hain GenoType MTBDRsl assays (version 1 and 2) by preventing the binding of wild-type probes. Moreover, such mutations can prevent the binding of mutant probes, designed for the identification of specific resistance mutations. Although these mutations are likely rare globally, they occur in approximately 7% of multidrug-resistant tuberculosis strains in some settings. ; T.M.W. is a University of Oxford National Institute for Health Research (NIHR) academic clinical lecturer. N.A. was supported by a doctoral study fund from Colciencias. T.S. was supported by grants from the Swedish Heart and Lung Foundation and the Marianne and Marcus Wallenberg Foundation. F.C. was supported by the Wellcome Trust (grant 201344/Z/16/Z). D.W.C. and T.E.A.P. are NIHR senior investigators supported by the NIHR Oxford Biomedical Research Centre, NIHR Oxford Health Protection Research Unit on Healthcare Associated Infection and Antimicrobial Resistance (grant HPRU-2012-10041), and the Health Innovation Challenge Fund (grant T5-358). S.N. was supported by grants from the German Center for Infection Research (DZIF), the European Union TB-PAN-NET (grant FP7-223681), and PathoNgenTrace (grant 278864). S.J.P. was supported by the Health Innovation Challenge Fund (grants HICF-T5-342 and WT098600), a parallel funding partnership between the UK Department of Health and Wellcome Trust. C.U.K. is a junior research fellow at Wolfson College, Cambridge.

Background The relationship between the presence of antibodies to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and the risk of subsequent reinfection remains unclear. Methods We investigated the incidence of SARS-CoV-2 infection confirmed by polymerase chain reaction (PCR) in seropositive and seronegative health care workers attending testing of asymptomatic and symptomatic staff at Oxford University Hospitals in the United Kingdom. Baseline antibody status was determined by anti-spike (primary analysis) and anti-nucleocapsid IgG assays, and staff members were followed for up to 31 weeks. We estimated the relative incidence of PCR-positive test results and new symptomatic infection according to antibody status, adjusting for age, participant-reported gender, and changes in incidence over time. Results A total of 12,541 health care workers participated and had anti-spike IgG measured; 11,364 were followed up after negative antibody results and 1265 after positive results, including 88 in whom seroconversion occurred during follow-up. A total of 223 anti-spike–seronegative health care workers had a positive PCR test (1.09 per 10,000 days at risk), 100 during screening while they were asymptomatic and 123 while symptomatic, whereas 2 anti-spike–seropositive health care workers had a positive PCR test (0.13 per 10,000 days at risk), and both workers were asymptomatic when tested (adjusted incidence rate ratio, 0.11; 95% confidence interval, 0.03 to 0.44; P=0.002). There were no symptomatic infections in workers with anti-spike antibodies. Rate ratios were similar when the anti-nucleocapsid IgG assay was used alone or in combination with the anti-spike IgG assay to determine baseline status. Conclusions The presence of anti-spike or anti-nucleocapsid IgG antibodies was associated with a substantially reduced risk of SARS-CoV-2 reinfection in the ensuing 6 months. (Funded by the U.K. Government Department of Health and Social Care and others.)