''Trichophyton mentagrophytes'' is a species in the fungal genus '' Trichophyton''. It is one of three common fungi which cause ringworm in companion animals. It is also the second-most commonly isolated fungus causing tinea infections in humans, and the most common or one of the most common fungi that cause zoonotic skin disease (i.e., transmission of

mycotic Fungal infection, also known as mycosis, is disease caused by fungi. Different types are traditionally divided according to the part of the body affected; superficial, subcutaneous, and systemic. Superficial fungal infections include common ti ...

skin disease from species to species). ''Trichophyton mentagrophytes'' is being frequently isolated from dogs, cats, rabbits,

guinea pig The guinea pig or domestic guinea pig (''Cavia porcellus''), also known as the cavy or domestic cavy (), is a species of rodent belonging to the genus '' Cavia'' in the family Caviidae. Breeders tend to use the word ''cavy'' to describe the ...

s and other rodents, though at least some genetic variants possess the potential of human-to-human transmission, e.g. Type VII and Type VIII. Particular genetic variants of the fungus have distinct geographic ranges.

Drug resistance

In ''T. mentagrophytes'', antifungal drug resistance is mainly associated with Type VIII isolates. Drug-resistant ''T. mentagrophytes'' strains have been found in many places across

Asia Asia (, ) is one of the world's most notable geographical regions, which is either considered a continent in its own right or a subcontinent of Eurasia, which shares the continental landmass of Afro-Eurasia with Africa. Asia covers an are ...

and

Europe Europe is a large peninsula conventionally considered a continent in its own right because of its great physical size and the weight of its history and traditions. Europe is also considered a Continent#Subcontinents, subcontinent of Eurasia ...

India India, officially the Republic of India (Hindi: ), is a country in South Asia. It is the List of countries and dependencies by area, seventh-largest country by area, the List of countries and dependencies by population, second-most populous ...

is the most affected country, with the rate of microbiological resistance to terbinafine estimated at 11.4%. There are also reports on terbinafine-resistant Type II isolates from

Japan Japan ( ja, 日本, or , and formally , ''Nihonkoku'') is an island country in East Asia. It is situated in the northwest Pacific Ocean, and is bordered on the west by the Sea of Japan, while extending from the Sea of Okhotsk in the n ...

and

Denmark ) , song = ( en, "King Christian stood by the lofty mast") , song_type = National and royal anthem , image_map = EU-Denmark.svg , map_caption = , subdivision_type = Sovereign state , subdivision_name = Kingdom of Denmark , establish ...

Molecular strain typing

For studies on the

epidemiology Epidemiology is the study and analysis of the distribution (who, when, and where), patterns and determinants of health and disease conditions in a defined population. It is a cornerstone of public health, and shapes policy decisions and evi ...

of ''T. mentagrophytes'', two molecular strain typing techniques are available. The first one is based upon amplification of nontranscribed spacer of

ribosomal DNA Ribosomal DNA (rDNA) is a DNA sequence that codes for ribosomal RNA. These sequences regulate transcription initiation and amplification, and contain both transcribed and non-transcribed spacer segments. In the human genome there are 5 chro ...

, and the second one involves a comparison of

internal transcribed spacer Internal transcribed spacer (ITS) is the spacer DNA situated between the small-subunit ribosomal RNA (rRNA) and large-subunit rRNA genes in the chromosome or the corresponding transcribed region in the polycistronic rRNA precursor transcript. ...

sequences within defined boundaries.

Nomenclature

Along with closely related '' T. interdigitale'', the species has been traditionally treated as a part of

polyphyletic assemblage A polyphyletic group is an assemblage of organisms or other evolving elements that is of mixed evolutionary origin. The term is often applied to groups that share similar features known as homoplasies, which are explained as a result of conver ...

, named "''T. mentagrophytes'' sensu lato". From 1999 to 2017 the two species have been collectively referred to as ''T. interdigitale'', while the name "''T. mentagrophytes''" has been used for current ''T. quinckeanum''. ''Trichophyton interdigitale'' seems to be strictly anthropophilic, and is associated with foot and nail infections.

Mating and meiosis

''Trichophyton mentagrophytes'' is capable of mating. This species is also able to undergo

meiosis Meiosis (; , since it is a reductional division) is a special type of cell division of germ cells in sexually-reproducing organisms that produces the gametes, such as sperm or egg cells. It involves two rounds of division that ultimately ...

.Weitzman I, Allderdice PW, Silva-Hutner M, Miller OJ. Meiosis in Arthroderma benhamiae (=Trichophyton mentagrophytes). Sabouraudia. 1968 Jun;6(3):232-7. PMID: 5679669 The haploid

chromosome complement Ploidy () is the number of complete sets of chromosomes in a cell, and hence the number of possible alleles for autosomal and pseudoautosomal genes. Sets of chromosomes refer to the number of maternal and paternal chromosome copies, respective ...

of ''T. mentagrophytes'' is four. The fusion of haploid nuclei ( karyogamy) preceding meiosis occurs in the penultimate cell of a typical crozier, an anatomical feature of the sexual phase of many fungi in the Division Ascomycota.

References

Arthrodermataceae {{eurotiomycetes-stub