Phenotypic and genomic hallmarks of a novel, potentially pathogenic rapidly growing Mycobacterium species related to the Mycobacterium fortuitum complex

Abstract

Previously, we have identified a putative novel rapidly growing Mycobacterium species, referred to as TNTM28, recovered from the sputum of an apparently immunocompetent young man with an underlying pulmonary disease. Here we provide a thorough characterization of TNTM28 genome sequence, which consists of one chromosome of 5,526,191 bp with a 67.3% G + C content, and a total of 5193 predicted coding sequences. Phylogenomic analyses revealed a deep-rooting relationship to the Mycobacterium fortuitum complex, thus suggesting a new taxonomic entity. TNTM28 was predicted to be a human pathogen with a probability of 0.804, reflecting the identification of several virulence factors, including export systems (Sec, Tat, and ESX), a nearly complete set of Mce proteins, toxin-antitoxins systems, and an extended range of other genes involved in intramacrophage replication and persistence (hspX, ahpC, sodA, sodC, katG, mgtC, ClpR, virS, etc.), some of which had likely been acquired through horizontal gene transfer. Such an arsenal of potential virulence factors, along with an almost intact ESX-1 locus, might have significantly contributed to TNTM28 pathogenicity, as witnessed by its ability to replicate efficiently in macrophages. Overall, the identification of this new species as a potential human pathogen will help to broaden our understanding of mycobacterial pathogenesis.

Comparative genome analysis reveals high-level drug resistance markers in a clinical isolate of Mycobacterium fortuitum subsp. fortuitum MF GZ001

“…The MF GZ001 has a wrinkled colony surface and rough morphotype which are consistent with a previous study (Gharbi et al, 2021). The rough morphotype M. fortuitum and M. abscessus comparatively possess more pathogenic potential (Brambilla et al, 2016;Gharbi et al, 2021). Recently, Dedrick et al, predicted the prophage length from 39.1 kb bp to 80.7 kb in clinical isolates, with an average size of ∼55.3 kbp (Dedrick et al, 2021), which was closely related to prophage (39.521 kb) from our clinical strain MF GZ001 and distantly related to prophage (<11.0 kb) from M. smegmatis (Jordan et al, 2014;Sewell, 2017).…”

Culture-Independent PCR Detection and Differentiation of Mycobacteria spp. in Antemortem Respiratory Samples from African Elephants (Loxodonta Africana) and Rhinoceros (Ceratotherium Simum, Diceros Bicornis) in South Africa

“…This could result in positive ESAT-6/CFP-10 PCR, but culture negative results (Table 1). For many of these NTMs, opportunistic human and animal infections have been reported [2,[33][34][35]. Two cases of atypical mycobacteriosis, caused by M. szulgai, have been reported in zoo elephants, as well as disease caused by M. kansasii infection in a bontebok herd, which were all positive for antibodies to ESAT-6/CFP-10 [16,36].…”

Culture-Independent PCR Detection and Differentiation of Mycobacteria spp. in Antemortem Respiratory Samples from African Elephants (Loxodonta africana) and Rhinoceros (Ceratotherium simum, Diceros bicornis) in South Africa

“…This could result in positive ESAT-6/CFP-10 PCR, but culture negative results (Table 1). For many of these NTMs, opportunistic human and animal infections have been reported [2,[34][35][36]. Two cases of atypical mycobacteriosis caused by M. szulgai have been reported in zoo elephants as well as disease caused by M. kansasii infection in a bontebok herd, which all were positive for antibodies to ESAT-6/CFP-10 [16,37].…”