Evaluation of Enzymatic Activity of Microsporum canis Isolates from Pet Cats by API-ZYM Test

Microsporum canis is one of the most common causes of zoonotic dermatophytosis. This study aimed to isolate M. canis from suspected cases of dermatophytosis in pet cats and evaluate the enzymatic activities.

(147) hair and skin samples were collected from pet cats suspected with dermatophytosis. Traditional laboratory methods were used for initial fungal isolation and identification, Confirmed by Conventional polymerase chain reaction. API ZYM test is used to determine the activity of enzymes secreted by M.canis isolated which have an important role in the pathogenicity of infection.

Microsporum canis was identified in 30/174 (17.2%) of the samples based on conventional mycological approaches and they show positive results by PCR. (30) isolates of M. canis were used for detection of their enzymatic activities by API ZYM test. The enzymatic activity profile revealed the highest activities for lipase, naphthol-AS-BI-phosphohydrolase, leucine arylamidase and esterase lipase (C8), each showed the activity percentage in 100%. (24) isolates (80%) with high activity of acid phosphatase, (6) isolates (3.3%) with no activity, followed by valine arylamidase in which five isolates (16.6%) produce this enzyme strongly while (25) isolates (83.3%) produced it moderately. Only one isolate (3.3) with high activity of cystine arylamidase and 29 isolates (96.6%) showed moderate activity. Twenty four isolates (80%) with high activity of acid phosphatase, 5 isolates (16.6%) with moderate activity and one isolate (3.3%) with no activity, a-glucosidase produced in 28 isolates (93.3) with strong activity and two isolates (6.6%) produce this enzyme moderately. It has become necessary to enhance the results of fungal identification by molecular methods like PCR, accompanied by measuring enzymes which considered as an important virulence factor of M.canis, contributing it is severity of the infection.