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La coccidioidomicosis es una enfermedad fúngica causada por el hongo Coccidioides, endémico en regiones áridas del hemisferio occidental como la franja fronteriza de México con EUA. Se transmite principalmente por la inhalación de esporas presentes en el suelo. Las manifestaciones que van desde asintomáticas hasta potencialmente mortales. La virulencia se relaciona con la capacidad del patógeno para multiplicarse y dañar al hospedero, requiriendo invasión activa de los tejidos. La identificación de estos factores y organismos susceptibles guía la investigación para desarrollar medidas preventivas o terapéuticas.

Tuberculosis (TB) remains a major health problem worldwide, and the emergence of multi-resistant strains to first-line drugs has become the biggest obstacle to its treatment. On the other hand, the incidence of non-tuberculous mycobacteria (NTM) in humans has increased remarkably in recent years. The search for new and better treatments against mycobacterial infections is a constant at the global level. Hence, in this study, we propose to investigate the antimycobacterial effect of the extracts and major compounds of Hedeoma drummondii against clinical isolates of Mycobacterium tuberculosis and non-tuberculous mycobacteria: M. abscessus, M. fortuitum, M. intracellulare, and M. gordonae. To determine the antimycobacterial activity, a microdilution assay was used to establish the minimum inhibitory concentration (MIC) of the different strains of Mycobacterium. The methanolic extract presented the best activity against M. tuberculosis, inhibiting ten of the twelve strains analyzed at a concentration < 2500 µg/mL; meanwhile, the hexanic extract presented the best activity against non-tuberculous mycobacteria (NTM) by inhibiting eight of the ten strains studied at ≤625 µg/mL. Moreover, there is a strong positive correlation between the antimycobacterial activity of pulegone and the hexanic extract against non-tuberculous strains, so this compound could serve as a predictability marker against these types of microorganisms.

The Mycobacterium tuberculosis complex (MTBC) is a successful human pathogen. In 2022, approximately 10.6 million people have developed the active phase of the disease, and around 1.6 million people died due to tuberculosis (TB). The deciphering of the genome of M. tb has helped us to understand its evolutionary history and the causes underlying its worldwide spread. Using various genotyping methods and whole-genome sequencing techniques indicate that the M. tb complex is grouped in nine lineages, some are specifically adapted to humans, while others are animal-adapted lineages. The presence of most of the lineages in Africa makes this continent the most likely place of MTBC origin. Studies of the genome of M. tb have also assisted in the identification of genes involved in its virulence, pathogenicity, and the long co-evolutionary process with its main host, the human being. In this review of selected literature, we describe the genotypic and phenotypic diversity of the MTBC and its clinical and epidemiological implications., El complejo de Mycobacterium tuberculosis (CMTB) es uno de los patógenos con mayor éxito evolutivo por su alta transmisión en las poblaciones humanas. En el 2022, la OMS estimó que aproximadamente 10.6 millones de personas desarrollaron la fase activa de la enfermedad, principalmente la forma pulmonar (tuberculosis pulmonar, TBP), y alrededor de 1.6 millones, más, fallecieron debido a la tuberculosis (TB). Diversas técnicas con base en el genotipo y la secuencia del genoma de Mycobacterium tuberculosis (M. tb) han permitido entender su historia evolutiva y comprender las causas de su propagación mundial. El análisis y las comparaciones de la secuencia de los genomas completos indican que el CMTB se compone de nueve linajes, algunos están específicamente adaptados a los humanos y otros a los animales. La presencia de la mayoría de los linajes en África, hace de este continente el origen del CMTB. Los estudios del genoma del CMTB también han hecho posible la identificación de los genes implicados en su virulencia y patogenicidad, así como en el largo proceso co-evolutivo con su principal hospedero, el ser humano. En esta revisión se describe la diversidad genotípica y fenotípica del CMTB y sus implicaciones clínicas y epidemiológicas.

Tuberculosis (TB) remains a major health problem worldwide, and the emergence of multi-resistant strains to first-line drugs has become the biggest obstacle to its treatment. On the other hand, the incidence of non-tuberculous mycobacteria (NTM) in humans has increased remarkably in recent years. The search for new and better treatments against mycobacterial infections is a constant at the global level. Hence, in this study, we propose to investigate the antimycobacterial effect of the extracts and major compounds of Hedeoma drummondii against clinical isolates of Mycobacterium tuberculosis and non-tuberculous mycobacteria: M. abscessus, M. fortuitum, M. intracellulare, and M. gordonae. To determine the antimycobacterial activity, a microdilution assay was used to establish the minimum inhibitory concentration (MIC) of the different strains of Mycobacterium. The methanolic extract presented the best activity against M. tuberculosis, inhibiting ten of the twelve strains analyzed at a concentration < 2500 µg/mL; meanwhile, the hexanic extract presented the best activity against non-tuberculous mycobacteria (NTM) by inhibiting eight of the ten strains studied at ≤625 µg/mL. Moreover, there is a strong positive correlation between the antimycobacterial activity of pulegone and the hexanic extract against non-tuberculous strains, so this compound could serve as a predictability marker against these types of microorganisms.

Marine environments represent a great opportunity for the discovery of compounds with a wide spectrum of bioactive properties. Due to their large variety and functions derived from natural selection, marine natural products may allow the identification of novel drugs based not only on newly discovered bioactive metabolites but also on already known compounds not yet thoroughly investigated. Since drug resistance has caused an increase in infections by Mycobacterium tuberculosis and nontuberculous mycobacteria, the re-evaluation of known bioactive metabolites has been suggested as a good approach to addressing this problem. In this sense, this study presents an evaluation of the in vitro effect of laurinterol and aplysin, two brominated sesquiterpenes isolated from Laurencia johnstonii, against nine M. tuberculosis strains and six nontuberculous mycobacteria (NTM). Laurinterol exhibited good antimycobacterial activity, especially against nontuberculous mycobacteria, being remarkable its effect against Mycobacterium abscessus, with minimum inhibitory concentration (MIC) values lower than those of the reference drug imipenem. This study provides further evidence for the antimycobacterial activity of some sesquiterpenes from L. johnstonii, which can be considered interesting lead compounds for the discovery of novel molecules to treat NTM infections.

Coccidioides immitis es un hongo dimorfo causante de la coccidioidomicosis. Esta es una infección que se presenta principalmente al sur de Estados Unidos y al norte de México. Existen distintos factores que determinan la virulencia de C. immitis, entre los cuales se encuentra la relación entre los macrófagos tisulares y las artroconidias de C. immitis. Esta infección fúngica puede causar un amplio espectro de manifestaciones clínicas, desde tomar un curso asintomático hasta padecer manifestaciones pulmonares graves o infección diseminada. Las manifestaciones cutáneas también pueden ocurrir tanto por diseminación hematógena como por inoculación directa, siendo la primera de estas la más frecuente. Existen factores de virulencia que presenta Coccidioides spp. como la envoltura hidrofóbica de la parte exterior de la pared del conidio que sirve como protección contra la destrucción de las enzimas y productos oxidativos liberados por las células de defensa del hospedero, la gran cantidad de endosporas que son liberadas por cada esférula y que cada una de ellas es una esférula potencial, y la sustancia mucilaginosa que envuelve a las endosporas cuando estas emergen de la esférula, la cual actúa como protección contra los fagocitos del hospedero. Los subcultivos se han usado extensamente para atenuar a los patógenos humanos, uno de estos es el ya conocido bacilo de Calmette y Guérin. Se han realizado estudios en nuestro servicio con Norcardia brasiliensis y Mycobacterium tuberculosis en donde se observa que pierden su virulencia al subcultivarse. El objetivo de este trabajo fue analizar el efecto del subcultivo de C. immitis sobre la virulencia del patógeno.

Leprosy is a chronic human disease caused by the yet-uncultured pathogen Mycobacterium leprae. Although readily curable with multidrug therapy (MDT), over 200,000 new cases are still reported annually. Here, we obtain M. leprae genome sequences from DNA extracted directly from patients’ skin biopsies using a customized protocol. Comparative and phylogenetic analysis of 154 genomes from 25 countries provides insight into evolution and antimicrobial resistance, uncovering lineages and phylogeographic trends, with the most ancestral strains linked to the Far East. In addition to known MDT-resistance mutations, we detect other mutations associated with antibiotic resistance, and retrace a potential stepwise emergence of extensive drug resistance in the pre-MDT era. Some of the previously undescribed mutations occur in genes that are apparently subject to positive selection, and two of these (ribD, fadD9) are restricted to drug-resistant strains. Finally, nonsense mutations in the nth excision repair gene are associated with greater sequence diversity and drug resistance.