Complication of Gynecomastia by Infection with a Novel Resistant Pseudomonas aeruginosa Strain in Male Goat

Abstract

Gynaecomastia is a glandular tissue proliferation leading to unilateral or bilateral enlargement of male mammary glands of man and animals. The present work describes a rare case of gynecomastia in a four-year-old Nubian buck. Place of Study: Departments of Microbiology, Pathology and Clinical Studies, College of Veterinary Medicine, King Faisal University, Al Ahsa, KSA.  Clinical examination revealed bilateral unequal enlargement of male rudimentary teats and both testicles were situated caudal to the udder. The animal performed well as a sire and produced liberal amount of normal milk from his udder. It was presented to the Veterinary Clinic for development of chronic mastitis. The case was referred to surgery and the decision was total amputation of the udder. On microbiological examination, Pseudomonas aeruginosa was identified by traditional methods and confirmed by the commercial VITEK 2 technique. Antimicrobial susceptibility test of the strain revealed resistance to common antibiotics in use to treat animals and was sensitive only for Aminoglycosides, Carbepenems, Cephalosporins and Lincosamides antimicrobial groups. Molecular bacteriology analysis by 16S rDNA sequence showed it is Pseud aeruginosa with only 99% similarity with the strains S164S, DQ8, PA96, PA1 and PA38182 pointing out it may be a new strain. Mastectomy was performed as radical treatment of gynaecomastia and chronic mastitis developed in the udder of the male goat. The animal performed well after surgery for up to two months follow-up. Histopathological examination demonstrated the udder connective tissue was completely transformed to multiform embryonic connective tissue with fibrosis. This picture is common in chronic infection and may not aid in differential diagnosis of the causes of gynaecomastia. The isolated Pseud aeruginosa strain was resistant to common antimicrobial agents with possible production of biosurfactants that induced development of chronic infection. Implication of gynecomastia in the health and performance of male goats and need to further investigate predisposing factors, are stressed.