Fate of antibiotic resistance genes in sewage treatment plant revealed by metagenomic approach

2014 ◽  
Vol 62 ◽  
pp. 97-106 ◽  
Author(s):  
Ying Yang ◽  
Bing Li ◽  
Shichun Zou ◽  
Herbert H.P. Fang ◽  
Tong Zhang
Entecho ◽  
2019 ◽  
Vol 2 (1) ◽  
pp. 6-12
Author(s):  
Ivan Karpíšek ◽  
Jitka Zachová ◽  
Dana Vejmelková ◽  
Vladimír Sýkora

Aktivovaný kal na čistírnách odpadních vod je neustále vystavován nízkým koncentracím antimikrobiálních látek a dalších léčiv. To vyvolává otázku, jak mikroorganismy k těmto látkám na čistírně odpadních vod přistupují. Zda jsou schopny se v tomto prostředí na tyto látky adaptovat, degradovat je, případně je využít jako substrát. Nebo jestli jsou tyto látky aktivovaným kalem opomíjeny. Pro posouzení adaptace aktivovaného kalu byla využita metoda PCR pro sledování genů resistence a testy biologické rozložitelnosti. Pro testy byl využit aktivovaný kal z ČOV a kal adaptovaný v laboratorních SBR modelech při koncentracích antibiotik 500 ng∙l−1 a 500 μg∙l−1. Biologická rozložitelnost byla posuzována dle normy ČSN ISO 14593. Testované látky byly sledovány pomocí skupinového stanovení celkového anorganického uhlíku. Jako testované látky byly vybrány: benzylpenicilin, ampicilin, streptomycin, erythromycin, chloramfenikol, sulfamethoxazol a trimetoprim. Aktivovaný kal z čistírny odpadních vod neměl vyvinutou aktivitu k biodegradaci testovaných antibiotik. Je pravděpodobné, že vysoké zatížení snadno biologicky rozložitelným substrátem a krátké zdržení odpadní vody na ČOV, vede k tomu, že mikroorganismy aktivovaného kalu nejsou nuceny tyto látky aktivně utilizovat a brání se jim pouze tvorbou obranných mechanismů pomocí genů antibiotické resistence. Nízké koncentrace antibiotik v SBR modelech vytvářely selekční tlak na mikroorganismy a podněcovaly šíření genů antibiotické resistence. English Activated sludge in wastewater treatment plants is constantly exposed to low concentrations of antimicrobials and other drugs. This raises the question of how microorganisms approach to these substances in the sewage treatment plant. Whether they can adapt, degrade, or use antibiotics as a substrate in this environment or the activated sludge neglects these substances. To assess the adaptation of activated sludge, the PCR method for monitoring antibiotic resistance genes and biodegradability tests were used. These tests were carried out with activated sludge from WWTP and sludge adapted in laboratory SBR models at 500 ng∙l−1 and 500 μg∙l−1 of chosen antibiotics. Their biodegradability was assessed according to ČSN ISO 14593. The tested substances were monitored by group determination of total inorganic carbon. The chosen substances were: benzylpenicillin, ampicillin, streptomycin, erythromycin, chloramphenicol, sulfamethoxazole and trimethoprim. Activated sludge had no developed activity for biodegradation of tested antibiotics. It is likely that the high load of readily biodegradable substrate and the short retention of the wastewater at the WWTP lead to the activated sludge not being forced to actively utilize these substances and will only prevent from them by forming defence mechanisms using antibiotic resistance genes. Low concentrations of antibiotics in SBR models produced selective pressure on microorganisms and stimulated the spread of antibiotic resistance genes.


2015 ◽  
Vol 188 ◽  
pp. 79-83 ◽  
Author(s):  
Anthony Naquin ◽  
Arsen Shrestha ◽  
Mingma Sherpa ◽  
Rajkumar Nathaniel ◽  
Raj Boopathy

Entecho ◽  
2019 ◽  
Vol 2 (1) ◽  
pp. 6-12
Author(s):  
Ivan Kapríšek ◽  
Jitka Zachová ◽  
Dana Vejmelková ◽  
Vladimír Sýkora

Aktivovaný kal na čistírnách odpadních vod je neustále vystavován nízkým koncentracím antimikrobiálních látek a dalších léčiv. To vyvolává otázku, jak mikroorganismy k těmto látkám na čistírně odpadních vod přistupují. Zda jsou schopny se v tomto prostředí na tyto látky adaptovat, degradovat je, případně je využít jako substrát. Nebo jestli jsou tyto látky aktivovaným kalem opomíjeny. Pro posouzení adaptace aktivovaného kalu byla využita metoda PCR pro sledování genů resistence a testy biologické rozložitelnosti. Pro testy byl využit aktivovaný kal z ČOV a kal adaptovaný v laboratorních SBR modelech při koncentracích antibiotik 500 ng∙l−1 a 500 μg∙l−1. Biologická rozložitelnost byla posuzována dle normy ČSN ISO 14593. Testované látky byly sledovány pomocí skupinového stanovení celkového anorganického uhlíku. Jako testované látky byly vybrány: benzylpenicilin, ampicilin, streptomycin, erythromycin, chloramfenikol, sulfamethoxazol a trimetoprim. Aktivovaný kal z čistírny odpadních vod neměl vyvinutou aktivitu k biodegradaci testovaných antibiotik. Je pravděpodobné, že vysoké zatížení snadno biologicky rozložitelným substrátem a krátké zdržení odpadní vody na ČOV, vede k tomu, že mikroorganismy aktivovaného kalu nejsou nuceny tyto látky aktivně utilizovat a brání se jim pouze tvorbou obranných mechanismů pomocí genů antibiotické resistence. Nízké koncentrace antibiotik v SBR modelech vytvářely selekční tlak na mikroorganismy a podněcovaly šíření genů antibiotické resistence. English Activated sludge in wastewater treatment plants is constantly exposed to low concentrations of antimicrobials and other drugs. This raises the question of how microorganisms approach to these substances in the sewage treatment plant. Whether they can adapt, degrade, or use antibiotics as a substrate in this environment or the activated sludge neglects these substances. To assess the adaptation of activated sludge, the PCR method for monitoring antibiotic resistance genes and biodegradability tests were used. These tests were carried out with activated sludge from WWTP and sludge adapted in laboratory SBR models at 500 ng∙l−1 and 500 μg∙l−1 of chosen antibiotics. Their biodegradability was assessed according to ČSN ISO 14593. The tested substances were monitored by group determination of total inorganic carbon. The chosen substances were: benzylpenicillin, ampicillin, streptomycin, erythromycin, chloramphenicol, sulfamethoxazole and trimethoprim. Activated sludge had no developed activity for biodegradation of tested antibiotics. It is likely that the high load of readily biodegradable substrate and the short retention of the wastewater at the WWTP lead to the activated sludge not being forced to actively utilize these substances and will only prevent from them by forming defence mechanisms using antibiotic resistance genes. Low concentrations of antibiotics in SBR models produced selective pressure on microorganisms and stimulated the spread of antibiotic resistance genes.


2019 ◽  
Author(s):  
Liguan Li ◽  
Arnaud Dechesne ◽  
Jonas Stenløkke Madsen ◽  
Joseph Nesme ◽  
Søren J. Sørensen ◽  
...  

AbstractThe current epidemic of antibiotic resistance has been facilitated by the wide and rapid horizontal dissemination of antibiotic resistance genes (ARGs) in microbial communities. Indeed, ARGs are often located on plasmids, which can efficiently shuttle genes across diverse taxa. While the existence conditions of plasmids have been extensively studied in a few model bacterial populations, their fate in complex bacterial communities is poorly understood. Here, we coupled plasmid transfer assays with serial growth experiments to investigate the persistence of the broad-host-range IncP-1 plasmid pKJK5 in microbial communities derived from a sewage treatment plant. The cultivation conditions combined different nutrient and oxygen levels, and were non-selective and non-conducive for liquid-phase conjugal transfer. Following initial transfer, the plasmid persisted in almost all conditions during a 10-day serial growth experiment (equivalent to 60 generations), with a transient transconjugant incidence up to 30%. By combining cell enumeration and sorting with amplicon sequencing, we mapped plasmid fitness effects across taxa of the microbial community. Unexpected plasmid fitness benefits were observed in multiple phylotypes of Aeromonas, Pseudomonas and Enterobacteriaceae, which resulted in community-level plasmid persistence. We demonstrate, for the first time, that plasmid fitness effects across community members can be estimated in a high-throughput way without prior isolation. By gaining a fitness benefit when carrying plasmids, members within complex microbial communities might have a hitherto unrecognized potential to maintain plasmids for long-term community-wide access.


2021 ◽  
Author(s):  
Hui Zhang ◽  
Hongwei Sun

Due to the irrational use of antibiotics, antibiotic resistance genes are widely present in the environmental media of our lives. Antibiotics have potential environmental and public health risks, and they bring harm to the environment in which we live. Sewage treatment plants are antibiotic resistance genes’ repository and important process for removing antibiotic resistance genes. The different processes they use in sewage treatment plants, the effect of removing antibiotic resistance genes is also different. In order to discuss the impact of different processes on the removal of antibiotic resistance genes, we selected three wastewater treatment plant samples with different treatment processes for testing, and used the fluorescence quantitative analysis technology of 16SrRNA gene to study the abundance, distribution and diversity of antibiotic resistance genes in different treatment processes. The results showed that the AAO process, the oxidation ditch process, and the CASS process all have high removal effect on antibiotic resistance genes, they all can reduce the diversity and abundance of antibiotic resistance genes, and the oxidation ditch process is the best process of the three treatment processes.


2021 ◽  
Author(s):  
Miguel Uyaguari

Abstract Background: Wastewater treatment plants are an essential part of maintaining the health and safety of the general public. However, they are also an anthropogenic source of antibiotic resistance genes. In this study, we characterized the resistome, the distribution of classes 1-3 integron-integrase genes (intI1, intI2, and intI3) as mobile genetic element biomarkers, and the bacterial and phage community compositions in the North End Sewage Treatment Plant in Winnipeg, Manitoba. Samples were collected from raw sewage, returned activated sludge, final effluent, and dewatered sludge. A total of 28 bacterial and viral metagenomes were sequenced over two seasons, fall and winter. Integron-integrase genes, the 16S rRNA gene, and the coliform beta-glucuronidase gene were also quantified during this time period. Results: Bacterial classes observed above 1% relative abundance in all treatments were Actinobacteria (39.24% ± 0.25%), Beta-proteobacteria (23.99% ± 0.16%), Gamma-proteobacteria (11.06% ± 0.09%), and Alpha-proteobacteria (9.18 ± 0.04%). Families within the Caudovirales order: Siphoviridae (48.69% ± 0.10%), Podoviridae (23.99% ± 0.07%), and Myoviridae (19.94% ± 0.09%) were the dominant phage observed throughout the NESTP. The most abundant bacterial genera (in terms of average percent relative abundance) in influent, returned activated sludge, final effluent, and sludge, respectively, includes Mycobacterium (37.4%, 18.3%, 46.1%, and 7.7%), Acidovorax (8.9%, 10.8%, 5.4%, and 1.3%), and Polaromonas (2.5%, 3.3%, 1.4%, and 0.4%).The most abundant class of antibiotic resistance in bacterial samples was tetracycline resistance (17.86% ± 0.03%) followed by peptide antibiotics (14.24% ± 0.03%), and macrolides (10.63% ± 0.02%). Similarly, the phage samples contained a higher prevalence of macrolide (30.12% ± 0.30%), peptide antibiotic (10.78% ± 0.13%), and tetracycline (8.69% ± 0.11%) resistance. In addition, intI1 was the most abundant integron-integrase gene throughout treatment (1.14x104 gene copies/mL) followed by intI3 (4.97x103 gene copies/mL) while intI2 abundance remained low (6.4x101 gene copies/mL).Conclusions: The wastewater treatment plant successfully reduced the abundance of bacteria, DNA bacteriophages, and antibiotic resistance genes although many of them still remained in effluent and biosolids. The presence of integron-integrase genes throughout treatment and in effluent suggests that antibiotic resistance genes could be actively disseminating resistance between both environmental and pathogenic bacteria.


PeerJ ◽  
2017 ◽  
Vol 5 ◽  
pp. e3269 ◽  
Author(s):  
Jess A. Millar ◽  
Rahul Raghavan

We explored the bacterial diversity of untreated sewage influent samples of a wastewater treatment plant in Tucson, AZ and discovered that Arcobacter cryaerophilus, an emerging human pathogen of animal origin, was the most dominant bacterium. The other highly prevalent bacteria were members of the phyla Bacteroidetes and Firmicutes, which are major constituents of human gut microbiome, indicating that bacteria of human and animal origin intermingle in sewage. By assembling a near-complete genome of A. cryaerophilus, we show that the bacterium has accumulated a large number of antibiotic resistance genes (ARGs) probably enabling it to thrive in the wastewater. We also determined that a majority of ARGs was being expressed in sewage, suggestive of trace levels of antibiotics or other stresses that could act as a selective force that amplifies multidrug resistant bacteria in municipal sewage. Because all bacteria are not eliminated even after several rounds of wastewater treatment, ARGs in sewage could affect public health due to their potential to contaminate environmental water.


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