Clinical diagnosis and characterization of Pseudomonas aeruginosa isolated from otitis in humans and cats

Abstract

Background: Pseudomonas aeruginosa is Gram-negative bacterium which recognized for its adaptability and opportunistic nature, with poses a substantial challenge in clinical settings due to its complicated antibiotic resistance mechanisms, biofilm formation, and capacity for persistent infections in both animal and human hosts.
Aims: This study aimed to isolate Pseudomonas aeruginosa bacteria that cause otitis in cats and their owners, and to study the clinical signs of the disease, as well as the morphological and biochemical characteristics of the bacteria.
Results: A total of 123 ear swabs were collected from humans (total number =53) and cats (total number=70) having otitis, in addition to 10 apparently healthy cats as controls Swabs were cultured in various agars (Nutrient, MacConkey, Blood, Cetrimide), tested biochemically, and confirmed by the VITEK 2 compact system. The results showed that (17.07%) of study samples were positive to P. aeruginosa, including (18.87%), in human and (15.71%) in cats. Case history and clinical examination revealed that the diseased human having ear discharge, pain, congestion, and hearing loss, while diseased cats were having pain on palpation, purulent discharge, head shaking, scratching, excessive earwax, and foul odor. Temperature, pulse rate, and respiration rates of positively infected cats were increased significantly (P≤ 0.05) when compared to control. The colonies of P. aeruginosa isolates were appeared as blue-green pigmentation on nutrient agar. In MacConkey agar, the growth was shown as pale yellowish, regular, flat, colorless margin colonies. Hemolysis in addition to smooth mucous and blue-green colonies with grape-like odor was identified in Blood agar. In Cetrimide agar, the colonies of P. aeruginosa produced water-soluble green pigment.

Conclusion: In conclusion, Pseudomonas aeruginosa is one of the main causes of ear infections which might be transmitted from humans to cats or vice versa. It should not be neglected when examining cases of ear infections.