A hypervariable genomic island identified in clinical and environmental Mycobacterium avium subsp hominissuis isolates from Germany

作者：Sanchini Andrea; Semmler Torsten; Mao Lei; Kumar Narender; Dematheis Flavia; Tandon Kshitij; Peddireddy Vidyullatha; Ahmed Niyaz; Lewin Astrid

来源：International Journal of Medical Microbiology, 2016, 306(7): 495-503.

DOI：10.1016/j.ijmm.2016.07.001

• Mycobacterium avium
• Mycobacterium avium subsp hominissuis
• Genomic island
• mmpL
• antibiotic-resistance
• horizontal gene transfer

Mycobacterium avium subsp. hominissuis (MAH) is an opportunistic human pathogen widespread in the environment. Genomic islands (GI)s represent a part of the accessory genome of bacteria and influence virulence, drug -resistance or fitness and trigger bacterial evolution. We previously identified a novel GI in four MAH genomes. Here, we further explored this GI in a larger collection of MAH isolates from Germany (n = 41), including 20 clinical and 21 environmental isolates. Based on comparative whole genome analysis, we detected this GI in 39/41 (95.1%) isolates. Although all these GIs integrated in the same insertion hotspot, there is high variability in the genetic structure of this GI: eight different types of GI have been identified, designated A-H (sized 6.2-73.3 kb). These GIs were arranged as single GI (23/41, 56.1%), combination of two different GIs (14/41, 34.1%) or combination of three different GIs (2/41, 4.9%) in the insertion hotspot. Moreover, two GI types shared more than 80% sequence identity with sequences of. M. canettii, responsible for Tuberculosis. A total of 253 different genes were identified in all GIs, among which the previously documented virulence -related genes mmpL10 and mce. The diversity of the GI and the sequence similarity with other mycobacteria suggests cross-species transfer, involving also highly pathogenic species. Shuffling of potential virulence genes such as mmpL10 via this GI may create new pathogens that can cause future outbreaks.

• 出版日期2016-11