Genomic analysis has markedly improved our knowledge of the M. tuberculosis transmission dynamics. The high-throughput analysis provided by the short-read platforms in reference laboratories assures the coverage of all TB cases in a population, guaranteeing the capture of all transmission chains. However, this strategy is associated to unavoidable delays until genomic data are available at a local level. We evaluate an alternative approach based on nanopore sequencing of primary cultures from every incident case, following a case-by-case pace. The strategy was evaluated in 23 stain-positive consecutive cases diagnosed in Almería, Spain along a 4-month period (March-July 2023). DNA was purified from LWJ primary cultures after less than 31 days of incubation for >90% of the cases. 20 sequencing runs were performed including 1-2 isolates; 7flow cells were used, recycling in the cases it was possible 4-6 times. Good coverages (>90% at >20X) were obtained after 51min-4 hours of sequencing, which allowed us to label the new cases, within the same day, as clustered (43.5%), or orphan (56.5%). Nanopore data fully correlated with those finally obtained by high-throughput short-read analysis. Our strategy may constitute a flexible and fast decentralized alternative for local settings, if we pursue that genomic data arrives timely for tailoring epidemiological intervention.