An Increase of Abundance and Transcriptional Activity for Acinetobacter junii Post Wastewater Treatment

Abstract

A membrane bioreactor (MBR)-based wastewater treatment plant (WWTP) in Saudi Arabia is assessed over a five-month period in 2015 and once in 2017 for bacterial diversity and transcriptional activity using metagenomics, metatranscriptomics and real time quantitative polymerase chain reaction (RT-qPCR). Acinetobacter spp. are shown to be enriched in the chlorinated effluent. Members of the Acinetobacter genus are the most abundant in the effluent and chlorinated effluent. At the species level, Acinetobacter junii have higher relative abundances post MBR and chlorination. RNA-seq analysis show that, in A. junii, 288 genes and 378 genes are significantly upregulated in the effluent and chlorinated effluent, respectively, with 98 genes being upregulated in both. RT-qPCR of samples in 2015 and 2017 confirm the upregulation observed in RNA-seq. Analysis of the 98 genes show that majority of the upregulated genes are involved in cellular repair and metabolism followed by resistance, virulence, and signaling. Additionally, two different subpopulations of A. junii are observed in the effluent and chlorinated effluent. The upregulation of cellular repair and metabolism genes, and the formation of different subpopulations of A. junii in both effluents provide insights into the mechanisms employed by A. junii to persist in the conditions of a WWTP.

Monitoring Antimicrobial Resistance Dissemination in Aquatic Systems

“…This special issue comprises of 11 research articles that fall within the scope of AMR. Broadly, topics extend from AMR monitoring and surveillance in environmental resources and effluents from water/wastewater treatment plants [32][33][34][35][36][37][38][39], antimicrobial ecological risk assessments of two river reservoir systems in China that are sources of drinking water supply [40,41], and exploring novel strategies of using engineered antimicrobial peptides (AMP) to target specific bacteria to disrupt biofilms that are major causes of chronic and persistent infections [42].…”

“…Jumat et al [37] conducted an ESBL study of diversity and transcriptional activity of bacteria in a WWTP in Saudi Arabia using metagenomics, metatranscriptomics and real-time qPCR. They found an increase in the relative abundance of Acinetobacter junii in MBR-and chlorinated treated effluent.…”

UV and bacteriophages as a chemical-free approach for cleaning membranes from anaerobic bioreactors

“…In addition, it was shown that certain bacteria, such as Acinetobacter spp. are strongly resistant to chemical disinfectants (14).…”

Nanoparticles applied in membrane bioreactors: potential impact on reactor performance and microbial communities

“…The presence of emerging contaminants (ECs) such as pharmaceuticals, illicit drugs, personal care products, antibiotic-resistant pathogens and antibiotic resistance genes in untreated wastewaters have been widely reported by many studies [1][2][3][4] . Heavy metals in influent of wastewater treatment plant located in Thuwal, Saudi Arabia was measured, and the result revealed heavy metal concentration to range from several ppb to more than 20000 ppb in the untreated wastewater 5 . Many of these ECs can detrimentally impact the natural ecosystems if left unremoved from the wastewaters.…”