Acinetobacter in Veterinary Medicine with emphasis on A. baumannii

Acinetobacter spp. are aerobic, rod-shaped Gram-negative bacteria belonging to the Moraxellaceae family of the class Gammaproteobacteria and are considered ubiquitous organisms. Among them, Acinetobacter baumannii is the most clinically significant species with an extraordinary ability to accumulate antimicrobial resistance and survive in the hospital environment. Recent reports indicate that A. baumannii has also evolved into a veterinary nosocomial pathogen. Although Acinetobacter spp. can be identified to species level by the use of the matrix-assisted laser ionization time-of-flight mass spectrometry (MALDI-TOF MS) coupled with an updated database, molecular techniques are still necessary for genotyping and determination of clonal lineages. It seems that the majority of infections due to A. baumannii in veterinary medicine are nosocomial. Such isolates have been associated with several type of infections such as canine pyoderma, feline necrotizing fasciitis, urinary tract infections, equine thrombophlebitis and lower respiratory tract infections, foal sepsis, pneumonia in mink and cutaneous lesions in hybrid falcon. Given the potential multidrug resistance of A. baumannii, treatment of diseased animals is often supportive and should be based preferably on in vitro antimicrobial susceptibility testing. It should be noted that animal isolates show a high genetic diversity and are in general distinct in their sequence types and resistance patterns from those found in humans. However, it cannot be excluded that animals may occasionally play a role as reservoir for A. baumannii. In line, it is of importance to implement infection control measures in veterinary hospitals to avoid nosocomial outbreaks with multidrug-resistant A. baumannii.