Antibiotic resistance profiles in cultivable microbiota isolated from some romanian natural fishery lakes included in Natura 2000 network

• Published in: BMC veterinary research Vol. 17; no. 1; p. 52
• Main Authors: Lazăr, Veronica, Gheorghe, Irina, Curutiu, Carmen, Savin, Ioana, Marinescu, Florica, Cristea, Violeta Corina, Dobre, Dumitru, Popa, Gabriela Loredana, Chifiriuc, Mariana Carmen, Popa, Mircea Ioan
• Format: Journal Article
• Language: English
• Published: London BioMed Central 26.01.2021; BioMed Central Ltd; BMC
• Subjects: aminoglycosides; Analysis; Anti-Bacterial Agents - pharmacology; Antibiotic resistance; Antibiotics; Antimicrobial agents; Antimicrobial resistance; Aquaculture; Aztreonam; Bacteria; Bacteriology and mycology; beta-lactamase; Cefazolin; Ceftazidime; Ceftriaxone; Cefuroxime; disk diffusion antimicrobial test; Drug resistance; Drug resistance in microorganisms; Drug Resistance, Bacterial; E coli; Enterobacterales; Enterococcus; Enterococcus - drug effects; Enterococcus - genetics; Enterococcus - isolation & purification; Enterococcus sp; ErmA gene; Erythromycin; fish; Fisheries; Food; genes; Genes, Bacterial - genetics; Integrase; integrases; Lakes; Lakes - microbiology; Lowland fishery lakes; Medicine; Medicine & Public Health; Microbial Sensitivity Tests; Microbiota; Microbiota (Symbiotic organisms); Microbiota - drug effects; Microbiota - genetics; Microorganisms; Multiplex Polymerase Chain Reaction; phenotype; Phenotypes; pollution; polymerase chain reaction; Quinolones; Research Article; risk; Romania - epidemiology; Sediments; species; Strains (organisms); Sulfonamides; Tetracyclines; Transgenics; Vancomycin; Veterinary Medicine/Veterinary Science; Water Microbiology; Zoology; β Lactamase; β-Lactam antibiotics; Romania; Lowland fishery lakes; sp; Antimicrobial resistance; Enterococcus sp; Enterobacterales
• ISSN: 1746-6148; 1746-6148
• DOI: 10.1186/s12917-021-02770-8

Background The present study aims the characterization of antibiotic resistance phenotypes and encoding genes in bacterial strains isolated from some Romanian aquatic fishery lowland salted lakes. Material/Methods This study was conducted on 44 bacterial strains, mainly belonging to species used as microbiological indicators of fecal pollution isolated from four natural fishery lakes. All strains were tested for their antibiotic susceptibility by disk diffusion method. Simplex and multiplex PCR were performed to identify the β-lactams antibiotic resistance genes ( bla NMD , bla OXA−48 , bla VIM , bla IMP , bla CTX−M , bla TEM ), sulfonamides (Sul1, Sul2), tetracyclines (TetA, TetB, TetC, TetD, TetM), aminoglycosides (aac3Ia), vancomycin (VanA, VanB, VanC), macrolides (ermA, ermB, ermC) as well as the plasmid-mediated quinolone resistance (PMQR) markers (QnrA, QnrB, QnrS), and class 1 integrons (Int1, drfA1-aadA1). Results The Enterococcus spp. isolates exhibited phenotypic resistance to vancomycin (35 %) and macrolides (erythromycin) (75 %); from the vancomycin – resistant strains, 5 % harboured VanA ( E. faecalis ), while the erythromycin resistant isolates were positive for the ermA gene ( E. faecalis − 10 %, E. faecium − 5 %). The Gram- negative rods (GNR) exhibited a high level of resistance to β-lactams: cefuroxime (63 %), cefazolin (42 %), ceftriaxone (8 %), ceftazidime and aztreonam (4 % each). The genetic determinants for beta-lactam resistance were represented by bla CTX−M−like (33 %), bla NDM−like and bla IMP−like (8.33 %) genes. The resistance to non-β-lactam antibiotics was ascertained to the following genes: quinolones (QnrS − 4.16 %); sulfonamides (Sul1–75 %, Sul2–4.16 %); aminoglycosides (aac3Ia − 4.16 %); tetracyclines (tetA – 25 %, tetC − 15 %). The integrase gene was found in more than 50 % of the studied strains (58.33 %). Conclusions The cultivable aquatic microbiota from fishery lakes is dominated by enterococci and Enterobacterales strains. The GNR strains exhibited high levels of β-lactam resistance mediated by extended spectrum beta-lactamases and metallo-β-lactamases. The Enterococcus sp. isolates were highly resistant to macrolides and vancomycin. The high level and diversity of resistance markers, correlated with a high frequency of integrons is suggesting that this environment could act as an important reservoir of antibiotic resistance genes with a great probability to be horizontally transmitted to other associated species from the aquatic sediments microbiota, raising the potential zoonotic risk for fish consumers.