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Abstract Mycobacterium abscessus is an opportunistic, extensively drug-resistant non-tuberculous mycobacterium. Few genomic studies consider its diversity in persistent infections. Our aim was to characterize microevolution/reinfection events in persistent infections. Fifty-three sequential isolates from 14 patients were sequenced to determine SNV-based distances, assign resistance mutations and characterize plasmids. Genomic analysis revealed 12 persistent cases (0-13 differential SNVs), one reinfection (15,956 SNVs) and one very complex case (23 sequential isolates over 192 months), in which a first period of persistence (58 months) involving the same genotype 1 was followed by identification of a genotype 2 (76 SNVs) in 6 additional alternating isolates; additionally, ten transient genotypes (88-243 SNVs) were found. A macrolide resistance mutation was identified from the second isolate. Despite high diversity, the genotypes shared a common phylogenetic ancestor and some coexisted in the same specimens. Genomic analysis is required to access the true intra-patient complexity behind persistent infections involving M. abscessus.

Background: SARS-CoV-2 genomic analysis has been key to the provision of valuable data to meet both epidemiological and clinical demands. High-throughput sequencing, generally Illumina-based, has been necessary to ensure the widest coverage in global variant tracking. However, a speedier response is needed for nosocomial outbreak analyses and rapid identification of patients infected by emerging VOCs. An alternative based on nanopore sequencing may be better suited to delivering a faster response when required; however, although there are several studies offering side-by-side comparisons of Illumina and nanopore sequencing, evaluations of the usefulness in the hospital routine of the faster availability of data provided by nanopore are still lacking. Results: We performed a prospective 10-week nanopore-based sequencing in MinION in a routine laboratory setting, including 83 specimens where a faster response time was necessary. The specimens analyzed corresponded to i) international travellers in which lineages were assigned to determine the proper management/special isolation of the patients; ii) nosocomial infections and health-care-worker infections, where SNP-based comparisons were required to rule in/out epidemiological relationships and tailor specific interventions iii) sentinel cases and breakthrough infections to timely report to the Public Health authorities. MinION-based sequencing was compared with the standard procedures, supported on Illumina sequencing; MinION accelerated the delivery of results (anticipating results 1-12 days) and reduced costs per sample by 28€ compared to Illumina, without reducing accuracy in SNP calling. Conclusions: Parallel integration of Illumina and nanopore sequencing strategies is a suitable solution to ensure both high-throughput and rapid response to cope with accelerating the surveillance demands of SARS-CoV-2 while also maintaining accuracy.

Centers for Disease Control and Prevention guidelines consider SARS-CoV-2 reinfection when sequential COVID-19 episodes occur >90 days apart. However, genomic diversity acquired over recent COVID-19 waves could mean previous infection provides insufficient cross-protection. We used genomic analysis to assess the percentage of early reinfections in a sample of 26 patients with 2 COVID-19 episodes separated by 20–45 days. Among sampled patients, 11 (42%) had reinfections involving different SARS-CoV-2 variants or subvariants. Another 4 cases were probable reinfections; 3 involved different strains from the same lineage or sublineage. Host genomic analysis confirmed the 2 sequential specimens belonged to the same patient. Among all reinfections, 36.4% involved non-Omicron, then Omicron lineages. Early reinfections showed no specific clinical patterns; 45% were among unvaccinated or incompletely vaccinated persons, 27% were among persons

IntroductionSince the COVID-19 outbreak, specific mRNA-based anti-SARS-CoV-2 vaccines have been developed and distributed worldwide. Because this is the first time that mRNA vaccines have been used, there are several questions regarding their capacity to confer immunity and the durability of the specific anti-SARS-CoV-2 response. Therefore, the objective of this study was to recruit a large cohort of healthcare workers from the Gregorio Marañón Hospital vaccinated with the mRNA-1273 or BNT126b2 vaccines and to follow-up on IgG anti-RBD levels at 8 months post-vaccination.MethodsWe recruited 4,970 volunteers and measured IgG anti-RBD antibodies on days 30 and 240 post-vaccination.ResultsWe observed that both vaccines induced high levels of antibodies on day 30, while a drastic wane was observed on day 240, where mRNA-1273 vaccinated induced higher levels than BNT162b2. Stratifying by vaccine type, age, gender, and comorbidities, we identified that older mRNA-1273-vaccinated volunteers had higher antibody levels than the younger volunteers, contrary to what was observed in the BNT162b2-vaccinated volunteers.DiscussionIn conclusion, we observed that mRNA-1273 has a higher capacity to induce a humoral response than BNT162b2 and that age is a factor in the specific response.