Comparison of subclinical dermatophyte infection in short- and long-haired cats

Dermatophytosis in Companion Animals in Portugal: A Comprehensive Epidemiological Retrospective Study of 12 Years (2012-2023)

Dermatophytosis, commonly referred to as ringworm, is a common superficial fungal infection in companion animals and humans. Between 2012 and 2023, plucked hair and scraped scale samples from domestic dogs and cats with clinical suspicion of dermatophytosis were collected from 355 veterinary medical centres across mainland Portugal. A total of 4716 animal samples were inoculated onto DERM agar, incubated at 25 °C for up to 4 weeks, and periodically examined macro- and micro-scopically to observe and evaluate fungal growth. Of these, 271 samples were removed due to contaminant fungi. Of the 568 positive cultures, the highest number were from the North (48.1%; 95% CI: 44.0-52.2%) and Centre (32.4%; 95% CI: 28.7-36.4%) regions. Microsporum canis was the most frequently isolated species (63.9%), followed by Trichophyton spp. (20.3%) and Nannizia gypsea (formerly Microsporum gypseum) (8.1%). Felines exhibited a higher frequency (17.4%) compared with dogs (9.1%) (p < 0.001). In dogs, the Yorkshire Terrier, West Highland White Terrier, Miniature Pinscher, Dalmatian and Miniature Schnauzer demonstrated a significant predisposition to dermatophytosis (p < 0.05). In cats, the Persian and Scottish Fold breeds were significantly predisposed (p < 0.05). No significant differences were found between sexes (p > 0.05). These findings underscore dermatophytosis as an increasing public health concern due to its zoonotic and contagious nature, providing comprehensive insights into the epidemiology of dermatophytosis in Portugal.

Comparative analysis of the distribution and antifungal susceptibility of yeast species in cat facial hair and human nails

Zoonotic yeast species have been implicated in disease development in both humans and cats. This study analyzed the yeast mycobiota present in feline facial hair and human nails and explored potential interspecies associations. A total of 118 biological specimens were examined, including 59 feline facial hair and 59 human nail samples. DNA extraction and DNA sequencing were performed to identify the specific yeast species. The most predominant yeast species in humans and cats were selected for antifungal susceptibility testing (itraconazole, ketoconazole, miconazole, and terbinafine). The findings unveiled diverse yeast species in cats and humans. Malassezia pachydermatis (45.8%) and Malassezia furfur (30.5%) were the most common yeast species in cats and humans, respectively. However, no significant correlation was detected between the yeast species identified in cats and their owners residing in the same household (p > 0.05). Miconazole exhibited the highest minimum inhibitory concentrations (MICs) against Malassezia pachydermatis and Malassezia furfur in both cat and human isolates, whereas terbinafine showed the lowest MICs against most Malassezia pachydermatis and Malassezia furfur in both cat and human isolates. Diverse yeast species in cat facial hair and human nails suggest possible cross-contamination among humans, pets, and environments.

Dermatophytosis caused by trichophyton mentagrophytes complex in organic pigs

BACKGROUND

Dermatophytosis (ringworm) caused by members of the Trichophyton mentagrophytes complex is rarely diagnosed in pigs but has been recognized as an increasingly common infection in humans. Further, resistance to antifungal drugs have been reported both in Asia and in Europe. This is the first scientific report of infection by the T. mentagrophytes complex in pigs in the Nordic countries.

CASE PRESENTATION

Skin lesions developed in grower pigs in an organic fattening pig farm with outdoor production and following laboratory analyses, dermatophytosis caused by members of the T. mentagrophytes complex was diagnosed. Infection was linked to poor hygiene, high humidity, and moderate outdoor temperatures, in combination with high pig density. A farm worker developed a skin lesion after close contact with affected pigs, which highlighted the zoonotic potential of porcine dermatophytosis. The dermatophytes may have originated from the herd supplying the growers where similar lesions occurred in pigs. Further, pigs from another organic fattening herd that received growers from the same supplier herd also developed dermatophytosis. The lesions healed without treatment as the housing conditions were improved. Isolation of affected pigs prevented spread to other pigs CONCLUSION: Members of the T. mentagrophytes complex can cause ringworm in pigs. The fungi probably persist in the haircoat and may cause overt disease when environmental conditions promote growth of mycelia.

Genetic Characterization of Microsporum canis Clinical Isolates in the United States

Microsporum canis is the primary agent causing dermatophytosis in cats, and also infects humans, dogs, and other species. Assessment of genetic variation among M. canis isolates in the United States has not been conducted. Further, M. canis mating type and assessment of disease severity associated with genotypic characteristics have not been rigorously evaluated. We therefore isolated M. canis from 191 domestic cats across the US and characterized genotypes by evaluation of ITS sequence, MAT locus, and microsatellite loci analysis. The genes SSU1 and SUB3, which are associated with keratin adhesion and digestion, were sequenced from a subset of isolates to evaluate potential genetic associations with virulence. Analysis of microsatellite makers revealed three M. canis genetic clusters. Both clinic location and disease severity were significant predictors of microsatellite variants. 100% of the M. canis isolates were MAT1-1 mating gene type, indicating that MAT1-2 is very rare or extinct in the US and that asexual reproduction is the dominant form of replication. No genetic variation at SSU1 and SUB3 was observed. These findings pave the way for novel testing modalities for M. canis and provide insights about transmission and ecology of this ubiquitous and relatively uncharacterized agent.

Prevalence of Microsporum canis from Pet Cats in Small Animal Hospitals, Chiang Mai, Thailand

Dermatophytosis is a disease caused by dermatophytes, a group of fungi that can cause disease both in humans and animals. The important genera that are pathogenic in animals include Trichophyton and Microsporum. Microsporum canis is an important species because it can cause zoonosis and is commonly found in domestic animals. Cats, which live very close to humans, may expose humans to this pathogen. This research focused on the epidemiology of M. canis found in cats. Hair samples were collected via the Mackenzie technique from cats with and without skin lesions, preliminarily examined with 10% KOH preparation, and cultured for fungal identification. Samples were confirmed with molecular techniques including polymerase chain reaction, gel electrophoresis, and sequencing. Samples were collected from 138 cats located in 93 households, 43 from cats with skin lesions (31.16%) and 95 from cats without skin lesions (68.84%). Eighteen cats with lesions (13.04%) and ten cats without lesions (7.2%) were found to carry M. canis. In eleven of the eighteen cats both with skin lesions and positive for M. canis (61.11%), the pathogen was found both at the site of the lesion and at other sites in the body. Because the pathogen can be found in the hair of cats with and without skin lesions, owners, keepers, veterinarians, and others who come into contact with these animals are at risk of infection if they are not aware or do not take precautions after contact with them.

Prevalence and in vitro antifungal susceptibility of commensal yeasts in the external ear canal of cats

Background

Lifestyle factors such as hair length, the frequency of ear cleaning and bathing, age, cat rearing, and sex may contribute to opportunistic yeast infections in the external ear canal of cats. This study aimed to determine the prevalence of commensal yeast organisms in cats’ external ear canals, evaluate their predisposing lifestyle factors, and test the susceptibility of Malassezia pachydermatis to antifungal agents.

Results

A total of 53 cats (33 male and 20 female) seronegative for feline leukemia virus and feline immunodeficiency virus were enrolled in this study. Their mean age (± standard deviation) was 6.04 (± 3.49) years. Fungal cultures and polymerase chain reaction tests were performed to identify the yeast species derived from the external ear canal. The association between lifestyle factors and the presence of M. pachydermatis was evaluated using Fisher’s exact test. The susceptibility of M. pachydermatis to antifungal agents was also analyzed. M. pachydermatis was the most frequently recovered yeast species, with a prevalence of 50.94 % (95 % confidence interval [CI]: 36.84–64.94 %). There was an association between hair length and a positive culture for M. pachydermatis (p = 0.0001). The odds of a negative culture for M. pachydermatis among short-haired cats was 11.67 (95 % CI, 3.22–42.24) times higher than that among long-haired cats (p = 0.0002). There was also an association between the frequency of ear cleaning and the presence of M. pachydermatis (p = 0.007). The odds of a negative culture for M. pachydermatis in cats that were receiving ear cleaning at intervals of ≤ 2 weeks was 5.78 (95 % CI, 1.67–19.94) times greater than that of cats receiving ear cleaning at intervals greater than 2 weeks or never (p = 0.0055). Ranges of minimum inhibitory concentrations (MICs) and minimum fungicidal concentrations for itraconazole, ketoconazole, miconazole, and terbinafine against M. pachydermatis were ≤ 0.063–4 and ≤ 0.063–≥32, ≤ 0.063–8 and 0.125–≥32, ≤ 0.063–≥32 and 0.5–≥32, and ≤ 0.016–1 and 0.125–8 µg/ml, respectively.

Conclusions

M. pachydermatis was the most commonly identified yeast organism in the external ear canal of healthy cats. Hair length and the frequency of ear cleaning played a role in the colonization of M. pachydermatis. The M. pachydermatis isolates had various MIC levels for common fungicides.