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Tracking down antibiotic-resistant Pseudomonas aeruginosa isolates in a wastewater network.

Slekovec C, Plantin J, Cholley P, Thouverez M, Talon D, Bertrand X, Hocquet D - PLoS ONE (2012)

Bottom Line: They were found in hospital wastewater and some produced ESBLs such as PER-1 and MBLs such as IMP-29.The WWTP greatly reduced P. aeruginosa counts in effluent, but the P. aeruginosa load in the river was nonetheless higher downstream than upstream from the WWTP.We conclude that the antibiotic-resistant P. aeruginosa released by hospitals is found in the water downstream from the WWTP and in sludge, constituting a potential risk of environmental contamination.

View Article: PubMed Central - PubMed

Affiliation: Service d'Hygiène Hospitalière, Centre Hospitalier Universitaire, Besançon, France.

ABSTRACT
The Pseudomonas aeruginosa-containing wastewater released by hospitals is treated by wastewater treatment plants (WWTPs), generating sludge, which is used as a fertilizer, and effluent, which is discharged into rivers. We evaluated the risk of dissemination of antibiotic-resistant P. aeruginosa (AR-PA) from the hospital to the environment via the wastewater network. Over a 10-week period, we sampled weekly 11 points (hospital and urban wastewater, untreated and treated water, sludge) of the wastewater network and the river upstream and downstream of the WWTP of a city in eastern France. We quantified the P. aeruginosa load by colony counting. We determined the susceptibility to 16 antibiotics of 225 isolates, which we sorted into three categories (wild-type, antibiotic-resistant and multidrug-resistant). Extended-spectrum β-lactamases (ESBLs) and metallo-β-lactamases (MBLs) were identified by gene sequencing. All non-wild-type isolates (n = 56) and a similar number of wild-type isolates (n = 54) were genotyped by pulsed-field gel electrophoresis and multilocus sequence typing. Almost all the samples (105/110, 95.5%) contained P. aeruginosa, with high loads in hospital wastewater and sludge (≥3×10(6) CFU/l or/kg). Most of the multidrug-resistant isolates belonged to ST235, CC111 and ST395. They were found in hospital wastewater and some produced ESBLs such as PER-1 and MBLs such as IMP-29. The WWTP greatly reduced P. aeruginosa counts in effluent, but the P. aeruginosa load in the river was nonetheless higher downstream than upstream from the WWTP. We conclude that the antibiotic-resistant P. aeruginosa released by hospitals is found in the water downstream from the WWTP and in sludge, constituting a potential risk of environmental contamination.

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Related in: MedlinePlus

Map of the study area.The large map indicates the precise location of the sampling sites, with the inset map indicating the location of the area in France.
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pone-0049300-g001: Map of the study area.The large map indicates the precise location of the sampling sites, with the inset map indicating the location of the area in France.

Mentions: This study was carried out in the city of Besançon, in eastern France (130,000 inhabitants). The WWTP studied serves approximately 120,000 people and had a mean hydraulic load in 2011 of 30,000 m3 per day. The effluent treated by the plant includes effluents from two University hospital sites, with 800 and 400 beds, urban wastewater and rainwater (Figure 1). The water is treated by a sequence of three typical treatments (sedimentation, biological content degradation and effluent polishing) before sludge production and the discharge of the treated effluent into the river. Of the 7,500 metric tons of sludge produced each year, 4,500 metric tons are used as fertilizer. The river upstream from the WWTP contained treated water originating from medical facilities 80 km upstream from the city of Besançon. Mean monthly rainfall was 46 mm during the study period, and 88 mm over the last decade.


Tracking down antibiotic-resistant Pseudomonas aeruginosa isolates in a wastewater network.

Slekovec C, Plantin J, Cholley P, Thouverez M, Talon D, Bertrand X, Hocquet D - PLoS ONE (2012)

Map of the study area.The large map indicates the precise location of the sampling sites, with the inset map indicating the location of the area in France.
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC3526604&req=5

pone-0049300-g001: Map of the study area.The large map indicates the precise location of the sampling sites, with the inset map indicating the location of the area in France.
Mentions: This study was carried out in the city of Besançon, in eastern France (130,000 inhabitants). The WWTP studied serves approximately 120,000 people and had a mean hydraulic load in 2011 of 30,000 m3 per day. The effluent treated by the plant includes effluents from two University hospital sites, with 800 and 400 beds, urban wastewater and rainwater (Figure 1). The water is treated by a sequence of three typical treatments (sedimentation, biological content degradation and effluent polishing) before sludge production and the discharge of the treated effluent into the river. Of the 7,500 metric tons of sludge produced each year, 4,500 metric tons are used as fertilizer. The river upstream from the WWTP contained treated water originating from medical facilities 80 km upstream from the city of Besançon. Mean monthly rainfall was 46 mm during the study period, and 88 mm over the last decade.

Bottom Line: They were found in hospital wastewater and some produced ESBLs such as PER-1 and MBLs such as IMP-29.The WWTP greatly reduced P. aeruginosa counts in effluent, but the P. aeruginosa load in the river was nonetheless higher downstream than upstream from the WWTP.We conclude that the antibiotic-resistant P. aeruginosa released by hospitals is found in the water downstream from the WWTP and in sludge, constituting a potential risk of environmental contamination.

View Article: PubMed Central - PubMed

Affiliation: Service d'Hygiène Hospitalière, Centre Hospitalier Universitaire, Besançon, France.

ABSTRACT
The Pseudomonas aeruginosa-containing wastewater released by hospitals is treated by wastewater treatment plants (WWTPs), generating sludge, which is used as a fertilizer, and effluent, which is discharged into rivers. We evaluated the risk of dissemination of antibiotic-resistant P. aeruginosa (AR-PA) from the hospital to the environment via the wastewater network. Over a 10-week period, we sampled weekly 11 points (hospital and urban wastewater, untreated and treated water, sludge) of the wastewater network and the river upstream and downstream of the WWTP of a city in eastern France. We quantified the P. aeruginosa load by colony counting. We determined the susceptibility to 16 antibiotics of 225 isolates, which we sorted into three categories (wild-type, antibiotic-resistant and multidrug-resistant). Extended-spectrum β-lactamases (ESBLs) and metallo-β-lactamases (MBLs) were identified by gene sequencing. All non-wild-type isolates (n = 56) and a similar number of wild-type isolates (n = 54) were genotyped by pulsed-field gel electrophoresis and multilocus sequence typing. Almost all the samples (105/110, 95.5%) contained P. aeruginosa, with high loads in hospital wastewater and sludge (≥3×10(6) CFU/l or/kg). Most of the multidrug-resistant isolates belonged to ST235, CC111 and ST395. They were found in hospital wastewater and some produced ESBLs such as PER-1 and MBLs such as IMP-29. The WWTP greatly reduced P. aeruginosa counts in effluent, but the P. aeruginosa load in the river was nonetheless higher downstream than upstream from the WWTP. We conclude that the antibiotic-resistant P. aeruginosa released by hospitals is found in the water downstream from the WWTP and in sludge, constituting a potential risk of environmental contamination.

Show MeSH
Related in: MedlinePlus