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Dahle, U. R.

Publications and source records attributed to Dahle, U. R..

2 recordsLinked to original sources

Impact of narrow spectrum Penicillin V on the oral and fecal resistome in a young child treated for otitis media

BackgroundAntibiotic overuse has led to a global emergence of resistant bacteria, and children are among the frequent users. Most studies with broad-spectrum antibiotics show severe impact on the resistome development of patients. Although narrow-spectrum antibiotics are believed to have less side-effects, their impact on the microbiome and resistome is mostly unknown. The aim of this study was to investigate the impact of the narrow-spectrum antibiotic phenoxymethylpenicillin (Penicillin V) on the microbiome and resistome of a child treated for acute otitis media (OM).\n\nMethodsOral and fecal samples were collected from a one-year child before (day 0) and after (day 5 and 30) receiving Penicillin V against OM. Metagenomic sequencing data was analysed to determine taxonomic profiling, using Kraken and Bracken software, and resistance profiling, using KMA in combination with the ResFinder database.\n\nResultsIn the oral samples, 11 antimicrobial resistance genes (ARGs), belonging to four classes, were identified at baseline. At day 5, the abundance of some ARGs was increased, some remained unchanged, while others disappeared. At day 30, most ARGs had returned to baseline levels, or lower. In the fecal samples we observed seven ARGs at baseline and five at day 5, with only one gene observed at day 5 being present at baseline. At day 30 the number of ARGs increased to 21 ARGs from 7 different classes.\n\nConclusionsPenicillin V had a remarkable impact on the fecal resistome indicating that even narrow-pectrum antibiotics may have important consequences in selecting for a more resistant microbiome.

microbiology↗

Genome-based transmission modeling separates imported tuberculosis from recent transmission within an immigrant population

BackgroundIn many countries tuberculosis incidence is low and largely shaped by immigrant populations from high-burden countries. This is the case in Norway, where more than 80 per cent of TB cases are found among immigrants from high-incidence countries. A variable latent period, low rates of evolution and structured social networks make separating import from within-border transmission a major conundrum to TB-control efforts in many low-incidence countries.\n\nMethodsClinical Mycobacterium tuberculosis isolates belonging to an unusually large genotype cluster associated with people born in the Horn of Africa, have been identified in Norway over the last two decades. We applied modeled transmission based on whole-genome sequence data to estimate infection times for individual patients. By contrasting these estimates with time of arrival in Norway, we estimate on a case-by-case basis whether patients were likely to have been infected before or after arrival.\n\nResultsIndependent import was responsible for the majority of cases, but we estimate that about a quarter of the patients had contracted TB in Norway.\n\nConclusionsThis study illuminates the transmission dynamics within an immigrant community. Our approach is broadly applicable to many settings where TB control programs can benefit from understanding when and where patients acquired tuberculosis.

epidemiology↗