Comparison of Extended-Spectrum Beta-Lactamase-Producing Escherichia coli Isolates From Rooks (Corvus frugilegus) and Contemporary Human-Derived Strains: A One Health Perspective

During winter, a large number of rooks gather and defecate at the park of a university clinic. We investigated the prevalence of extended-spectrum beta-lactamase (ESBL)–producing Escherichia coli in these birds and compared recovered isolates with contemporary human isolates. In 2016, fecal samples were collected from 112 trap-captured rooks and investigated for presence of ESBL producers using eosin methylene blue agar supplemented by 2 mg/L cefotaxime; 2,455 contemporary human fecal samples of patients of the clinics sent for routine culturing were tested similarly. In addition, 42 ESBL-producing E. coli isolates collected during the same period from inpatients were also studied. ESBL genes were sought for by PCR and were characterized by sequencing; E. coli ST131 clones were identified. Epidemiological relatedness was determined by pulsed-field gel electrophoresis and confirmed using whole genome sequencing in selected cases. Thirty-seven (33%) of sampled rooks and 42 (1.7%) of human stools yielded ESBL-producing E coli. Dominant genes were blaCTX–M–55 and blaCTX–M–27 in corvid, blaCTX–M–15 and blaCTX–M–27 in human isolates. ST162 was common among rooks. Two rook-derived E. coli belonged to ST131 C1-M27, which was also predominant (10/42) among human fecal and (15/42) human clinical isolates. Another potential link between rooks and humans was a single ST744 rook isolate grouped with one human fecal and three clinical isolates. Despite possible contact, genotypes shared between rooks and humans were rare. Thus, rooks are important as long-distance vectors and reservoirs of ESBL-producing E. coli rather than direct sources of infections to humans in our setting.

Arthroderma tuberculatum and Arthroderma multifidum Isolated from Soils in Rook (Corvus frugilegus) Colonies as Producers of Keratinolytic Enzymes and Mineral Forms of N and S

Keratinolytic fungi representing the genus Arthroderma that were isolated from the soils of a rook (Corvus frugilegus) colony were used as biological agents for the disposal of waste feathers. The aim of this study was to assess the abilities of Arthroderma tuberculatum and Arthroderma multifidum fungi with a varied inflow of keratin matter to biodegrade waste feathers. The evaluation was based on the determination of feather mass loss, the activity of keratinolytic enzymes, and the content of mineral N and S forms. It was found that the activity of protease released by the fungi contributed to an increase in the level of soluble proteins and peptides and the concentration of ammonium ions, as well as alkalization of the culture medium. Keratinase activity was significantly correlated with sulfate release, especially in A. tuberculatum cultures. The strains of A. tuberculatum fungi isolated from the soil with the highest supply of organic matter, i.e., strains III, IV, and V, had the lowest enzymatic activity, compared to the A. multifidum strains, but they released mineral nitrogen and sulfur forms that are highly important for fertilization, as well as nutritionally important peptides and amino acids. A. tuberculatum strains can be used for the management of waste feathers that can be applied in agricultural practice.