Occurrence of Trichophyton verrucosum in cattle in the Ningxia Hui autonomous region, China

Eukaryotic Infections in Dairy Calves: Impacts, Diagnosis, and Strategies for Prevention and Control

Eukaryotic infections are common among dairy calves and can have significant impacts on their health and growth rates. Fungal infections caused by Aspergillus fumigatus, Trichophyton verrucosum, and Candida albicans can cause respiratory diseases, dermatophytosis, and diarrhea, respectively. Protozoan parasites, including Cryptosporidium parvum, Giardia duodenalis, and Eimeria spp., are also common in dairy calves. C. parvum is highly contagious and can cause severe diarrhea and dehydration, while Giardia duodenalis can lead to poor growth and is transmissible to humans through contaminated food or water. Eimeria spp. can cause coccidiosis and lead to reduced growth rates, poor feed conversion, and death. The common helminthic infections in dairy calves include Ostertagia ostertagi, Cooperia spp., Fasciola hepatica, and Strongyloides papillosus. These parasitic infections significantly impact calf health, growth, and dairy industry productivity. Diagnosis of these infections can be made through fecal samples using microscopy or molecular methods. However, diagnosis of the infections can be challenging and requires a combination of clinical signs and laboratory tests such as culture and PCR. Preventing and controlling eukaryotic infections in dairy calves requires several measures. Good hygiene and sanitation practices, proper management strategies, and timely treatment of affected animals are important. It is also necessary to avoid overcrowding and consider vaccination against ringworm. Further research is needed to better understand the epidemiology and characterization of eukaryotic infections in dairy calves, which will help in the development of more effective prevention and control strategies. In general, good hygiene practices, appropriate management strategies, and timely treatment of affected animals are crucial in preventing and controlling the infections, ensuring the health and well-being of dairy calves.

Molecular study and antifungal susceptibility profile of Trichophyton rubrum and Trichophyton mentagrophytes strains isolated from lesions of humans and cattle

Background and Objectives

Monitoring of contagious diseases is important to advance our knowledge of their epidemiology and to enable more impressive investigation and prevention efforts. This study aimed to examine antifungal drug susceptibility and molecular analysis of clinical isolates of Trichophyton rubrum and Trichophyton mentagrophytes in humans and cattle.

Materials and Methods

A total of 400 patients and 500 cattle were evaluated in this study. Dermatophytosis was confirmed in cases by direct microscopy and culture methods. Antifungal drug susceptibility profiles, MIC₅₀, and MIC₉₀ of isolates were determined using the broth microdilution method. Multiplex-PCR, RAPD PCR, and sequencing methods were used for the genetic analysis of virulence genes and the ITS1 and ITS2 regions, respectively.

Results

A total of 175 patients and 120 cattle were diagnosed with dermatophytosis. Dermatophytes showed a remarkable rate (30%) of terbinafine resistance. T. mentagrophytes showed lower susceptibility than T. rubrum (MIC₅₀ =16 μg/mL). Strains harboring Mep1, Mep2, and Mep4 genes had the highest frequency among all genotypes. A RAPD-PCR dendrogram divided T. mentagrophytes and T. rubrum strains into three and six groups, respectively.

Conclusion

A notable rate of resistance to terbinafine in isolated dermatophytes was reported in this study. Examination of RAPD-PCR results showed that T. rubrum strains had higher genetic diversity than T. mentagrophytes. Genetic monitoring of dermatophytes must be considered an important factor in providing fungal infection prevention and treatment approaches.