Antibiotic resistance profile of main bacterial genera according to taxonomic classification and mechanisms of action. (a) Penicillin-resistant bacteria; (b) tetracycline-resistant bacteria. Darkness indicates degrees of resistance. Alpha, Beta and Gamma groups indicate Alpha-, Beta- and Gammaproteobacteria, respectively. Ami, amikacin; Gen, gentamycin; Kan, kanamycin; Tet, tetracycline; Hyg, hygromycin; Ery, erythromycin; Chl, chloramphenicol; Amp, ampicillin; Cip, ciprofloxacin; Nov, novobiocin; Rif, rifampicin; Tri, trimethoprim.