Related Experiment Video
Updated: Jun 22, 2026
06:34
Identification of Rare Bacterial Pathogens by 16S rRNA Gene Sequencing and MALDI-TOF MS
Published on: July 11, 2016
Mycobacterium insubricum sp. nov.
Enrico Tortoli1, Serena Baruzzo, Yvonne Heijdra
1Mycobacteriology Reference Center, Microbiology Laboratory, Careggi Hospital, Florence, Italy. e.tortoli@libero.it
Summary
Five novel Mycobacterium strains were identified, distinct from known species. Genetic analysis, including 16S rRNA sequencing, confirmed these non-pigmented rapid growers as a new species, Mycobacterium insubricum.
Area of Science:
- Microbiology
- Bacteriology
- Mycobacteriology
Background:
- Clinical samples can harbor unrecognized bacterial species.
- Distinguishing novel Mycobacterium species is crucial for accurate diagnostics and understanding microbial diversity.
Purpose of the Study:
- To characterize five phenotypically and genotypically distinct Mycobacterium strains.
- To determine if these strains represent a novel species within the Mycobacterium genus.
Main Methods:
- Phenotypic analysis including cell-wall lipid profiling.
- Genotypic analysis using 16S rRNA, hsp65, rpoB gene sequencing, and 16S-23S rRNA gene internal transcribed spacer (ITS) sequencing.
- Polymerase chain reaction (PCR) restriction fragment length polymorphism (RFLP) analysis.
Main Results:
- The five strains exhibited unique phenotypic traits, including non-pigmented rapid growth and a cell-wall lipid pattern similar to Mycobacterium brumae and Mycobacterium fallax.
- Multigene sequencing (16S rRNA, hsp65, rpoB, ITS) demonstrated significant genetic divergence from all recognized Mycobacterium species.
- The internal transcribed spacer (ITS) region showed striking variability, with only limited homology to other mycobacteria.
- PCR restriction analysis patterns were distinct from previously reported strains.
Conclusions:
- The five strains represent a novel species, proposed as Mycobacterium insubricum sp. nov.
- The genetic distinctiveness, particularly in the ITS region, supports the classification of Mycobacterium insubricum as a new species.
- This finding expands the known diversity within the Mycobacterium genus.
Related Concept Videos
01:30Bacterial Phylum Actinobacteria
Coryneform bacteria are gram-positive, aerobic, nonmotile rods that exhibit irregular, club-shaped, or V-shaped arrangements. Their V-shape results from snapping division, where the inner cell wall layer forms the cross-wall, while the outer layer remains intact until it ruptures on one side, causing the daughter cells to bend away.The primary genera are Corynebacterium and Arthrobacter. Corynebacterium includes diverse species, ranging from saprophytes to pathogens like Corynebacterium...
01:26Pulmonary Tuberculosis IV
Tuberculosis, more commonly referred to as TB, is an infectious disease stemming from Mycobacterium tuberculosis. While it primarily impacts the lungs, TB can also affect other body areas. Given its severity and global impact, timely and accurate diagnosis is crucial for controlling its spread and improving patient outcomes.
Several diagnostic approaches are used to detect TB. The conventional method is the Tuberculin Skin Test (TST), also known as the Mantoux test. However, this method has...
Several diagnostic approaches are used to detect TB. The conventional method is the Tuberculin Skin Test (TST), also known as the Mantoux test. However, this method has...
01:23Tuberculosis
Tuberculosis (TB) remains a significant global health concern, primarily targeting the lungs and spreading through airborne transmission. Infection begins when aerosolized droplet nuclei, expelled by an individual with active TB, are inhaled by another person. These microscopic particles carry Mycobacterium tuberculosis, the causative agent of TB. Upon reaching the alveoli, the bacilli are engulfed by alveolar macrophages. However, due to their specialized lipid-rich cell wall, these pathogens...
01:24Bacterial Phylum Tenericutes
The phylum Tenericutes, which includes the single class Mollicutes, comprises bacteria that lack cell walls. The term "Mollicutes" derives from the Latin word mollis, meaning "soft." These organisms are among the smallest known and are commonly referred to as mycoplasmas due to the prominence of the genus Mycoplasma, which includes well-known human pathogens. Despite their inability to stain gram-positively (a result of their lack of cell walls), mycoplasmas are phylogenetically related to the...
01:31Pulmonary Tuberculosis III
Tuberculosis (TB) is a contagious infection primarily affecting the lung parenchyma but which can also affect other body parts. TB can be classified based on disease development, presentation, and the affected anatomical site.
The first classification is based on the development of the disease, and it includes the following categories:
The first classification is based on the development of the disease, and it includes the following categories:
01:29Pulmonary Tuberculosis I
Tuberculosis, often called TB, is a contagious illness primarily caused by Mycobacterium tuberculosis. It mainly affects the lung parenchyma but can also impact other body parts.
Causative Organism
The primary infectious agent causing tuberculosis is Mycobacterium tuberculosis, a slow-growing, acid-fast, aerobic rod that exhibits sensitivity to heat and ultraviolet light. Instances of Mycobacterium bovis and Mycobacterium avium contributing to the development of TB infection are rare.
Mode of...
Causative Organism
The primary infectious agent causing tuberculosis is Mycobacterium tuberculosis, a slow-growing, acid-fast, aerobic rod that exhibits sensitivity to heat and ultraviolet light. Instances of Mycobacterium bovis and Mycobacterium avium contributing to the development of TB infection are rare.
Mode of...