[Phenotypical antibiotic resistances of bacteriological isolates originating from pet, zoo and falconry birds]

The prevalence of resistant bacteria in pet birds, zoo birds and falconry birds is still largely unknown. Therefore, antibiograms of rapidly-growing aerobic bacteria obtained from these birds were retrospectively evaluated.

Between 2007 and 2016 a total of 1036 antibiograms were evaluated. The bacteria isolates originated from 811 birds of 20 zoological orders (mostly Psittaciformes [61.8 %] and Passeriformes [14.5 %] and from alive patients or pathological examinations. The birds were primarily kept in Southern Germany. Phenotypic in vitro sensitivity of bacterial isolates to various antibiotics was determined using a standardized agar diffusion test.

The most frequently examined bacteria species were Escherichia coli (n = 386 isolates), Staphylococcus (S.). aureus (n = 150), Enterobacter cloacae (n = 122), Klebsiella pneumoniae (n = 86) and Pseudomonas aeruginosa (n = 64). Resistance to at least one antibiotic agent was detected in 53.1 % of the E. coli isolates, most commonly to doxycycline (50.3 %) and ampicillin (46.1 %), as well as in 95.9 % of Enterococcus faecalis isolates and 78.0 % of Staphylococcus aureus isolates. Multidrug resistance to 3 or more antibiotic groups was frequent in S. aureus (37.3 % of isolates). Resistance rates were higher in isolates from pet birds and captive birds of prey than in isolates from zoo birds.Resistant isolates were more common in Psittaciformes than in Passeriformes. An increasing resistance rate for fluoroquinolones in E. coli (a minimum of 0 % in 2005 and a maximum of 27.3 % in 2011) and decreasing resistance rates for tetracyclines in S. aureus (a maximum of 38.2 % in 2007 and lowest values of 0 % in 2014 and 2015) were observed over the examined period.

The detected resistance rates of bacteria in pet birds, zoo birds and falconry birds must be considered as being problematic. They indicate the importance of microbial sensitivity testing for a conscientious therapy of pet birds, zoo birds and falconry birds. Critical treatment situations may arise from infections with S. aureus.