Mycobacterium microti : More Widespread than Previously Thought

Abstract

Letters to the Editor Mycobacterium microti: More Widespread than Previously Thought Mycobacterium microti typically causes disease in voles, wood mice, and shrews (6). Only rarely has this bacterium been isolated from other animals, among which are a llama, cats, pigs, a rock hyrax, and a ferret (2, 4, 5). Recently, M. microti isolates from different sources were characterized by using novel genetic markers (5), and this study for the first time disclosed four cases of M. microti infections in humans in The Netherlands. Here we describe the finding of additional M. microti infections in animals and a human in the United Kingdom (UK) that were identified by spoligotyping (3). In the framework of a European Union project on the development of novel standardized methodology for the identification of and nomenclature for Mycobacterium bovis, spoli

Molecular epidemiology of tuberculosis and other mycobacterial infections: main methodologies and achievements

“…The subspecies in the complex: M. tuberculosis, M. bovis, M. africanum, M. microti and M. canettii , and the attenuated M. bovis BCG bacteria that constitutes the vaccine against tuberculosis are often difficult to distinguish on the basis of biochemical tests or growth characteristics. DNA fingerprinting is therefore increasingly applied to classify M. tuberculosis complex isolates into subspecies [39–41, 46–62] Identification to the subspecies level may have important implications for the epidemiology of the respective case, as M. bovis strains are thought not to be transmitted amongst humans. It should be noted that the term ‘strain typing’ should be reserved for the distinction of strains within a (sub)species.…”

“…Most M. bovis and all M. bovis BCG strains lack, in addition, spacers 3, 9 and 16 [120, 125, 154]. M. microti strains can be distinguished in ‘vole’ and ‘lama’ types by their characteristic spoligo patterns [41, 49].…”

Tuberculosis Caused by Mycobacterium microti in South American Camelids

“…17 In cats, M. microti has been assumed to be acquired from infected wild rodents, but this assumption has not been supported by the results of genotyping analyses. 5,27,47 To the authors' knowledge, no study has been carried out to determine the prevalence of tuberculosis in Swiss wild field vole populations as was undertaken by Burthe et al 19 in England. The owner of herd 1 was asked to trap wild field voles near the hayrack of SAC in his barn because of the potential implications of these rodents as a reservoir of M. microti.…”

“…5,17,[19][20][21][22][23][24][25][26][27][28] Limited information currently is available regarding the manifestations of M. microti infection in South American camelids (SAC). 5,26,27,29 To date, no appropriate antemortem clinical test for M. microti infection in animals is available. Comparative intradermal tuberculin testing with bovine protein purified derivate (PPD) and avian PPD appears to be inconclusive, 30 and specific intradermal tuberculin tests using M. microti antigens are not established.…”

A novel multi SNP based method for the identification of subspecies and associated lineages and sub-lineages of theMycobacterium tuberculosiscomplex by whole genome sequencing

“…There were three clinical isolates of M. microti , all of which were also correctly identified by Mykrobe predictor but not KvarQ or TB-Profiler with their default reference libraries. There have been at least 26 cases of M. microti infection in humans reported in the literature both with and without close contact with relevant animals being a feature of the clinical history 22,[49][50][51][52][53] . In a case series from Scotland, three out of four M. microti infections occurred in individuals not known to be immunocompromised and two of these had no known contacts with relevant animals 51 .…”