Comparison of microbial communities in sequencing batch reactors (SBRs) exposed to trace erythromycin and erythromycin-H₂O

• Published in: Applied microbiology and biotechnology Vol. 98; no. 6; pp. 2667 - 2673
• Main Authors: Wang, Shanquan, Fan, Caian, Low, Adrian, He, Jianzhong
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer-Verlag 01.03.2014; Springer Berlin Heidelberg; Springer Nature B.V
• Subjects: Acidobacteria; Actinobacteria; Analysis; Anti-Bacterial Agents - metabolism; Antibiotic resistance; Antibiotics; Antimicrobial agents; Bacteria; Bacteria - classification; Bacteria - drug effects; Bacteria - genetics; Batch reactors; biofilm; Biofilms; Biomedical and Life Sciences; Bioreactors - microbiology; Biota; Biotechnology; Control systems; Dechloromonas; DNA, Bacterial - chemistry; DNA, Bacterial - genetics; DNA, Ribosomal - chemistry; DNA, Ribosomal - genetics; Drug resistance; Environmental Biotechnology; erythromycin; Erythromycin - metabolism; Genes; Health; human health; Life Sciences; Membrane reactors; Microarray Analysis; microarray technology; Microbial activity; microbial communities; Microbial Genetics and Genomics; Microbiology; Microorganisms; Molecular Sequence Data; Nitrospira; proteins; Reactors; RNA, Ribosomal, 16S - genetics; Sequence Analysis, DNA; Sludge; Studies; Taxonomy; Thauera; Waste Water - microbiology; wastewater treatment; Wastewater treatment plants; Water treatment; Water treatment plants; Zoogloea; Erythromycin (ERY); Antibiotics; PhyloChip; Sequencing batch reactors (SBRs); Microbial community; Dehydrated erythromycin (ERY-H; O
• ISSN: 0175-7598; 1432-0614
• DOI: 10.1007/s00253-013-5205-2

Wastewater treatment plants (WWTPs) are major collection pools of antibiotics of which low concentrations may induce antibiotic resistance in their microbial communities and pose threat to human health. However, information is still limited on the microbial community alteration in WWTPs upon exposure to low-dose antibiotics due to absence of negative control systems without input of resistant bacteria and resistance genes. Here we report the impact of trace erythromycin (ERY) and dehydrated erythromycin (ERY-H₂O) on microbial community dynamics in three long-term (1 year) running sequencing batch reactors (SBRs), R1 (ERY-H₂O), R2 (ERY), and negative control R3. The PhyloChip microarray analysis showed that ERY-H₂O and ERY significantly altered their microbial communities based on bacterial richness (e.g., 825 operational taxonomic units (OTUs) in R1, 699 OTUs in R2, and 920 OTUs in R3) and population abundance (15 and 48 subfamilies with >80 % abundance decrease in R1 and R2, respectively). ERY-H₂O and ERY have broad but distinct antimicrobial spectrums. For example, bacteria of all the major phyla (i.e., Proteobacteria, Actinobacteria, Bacteroidetes, and Chloroflexi) present in SBRs were severely inhibited by ERY-H₂O and ERY, but bacteria of Acidobacteria, Chlorobi, Firmicutes, Nitrospira and OP10 phyla were only inhibited by ERY. Very limited bacterial groups showed antibiotic resistance to ERY-H₂O or ERY through forming biofilms (e.g., Zoogloea) or synthesizing resistant proteins (e.g., Thauera, Candidatus Accumulibacter, Candidatus Competibacter, and Dechloromonas) in the SBRs. Inhibition was observed to be the main effect of ERY-H₂O and ERY on microbial communities in the reactors. The results would broaden our knowledge of effects of low-dose antibiotics on microbial communities in WWTPs.