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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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Minimal spanning tree analysis of P. aeruginosa strains based on MLST data and isolation sites.
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pone-0049300-g004: Minimal spanning tree analysis of P. aeruginosa strains based on MLST data and isolation sites.

Mentions: As PFGE typing is more discriminatory than MLST, we assumed that all the isolates with a given PT belonged to the same ST. We therefore determined the MLST profiles of the 54 PTs including at least one resistant or multi-resistant isolate. These 54 PTs included 81 isolates: 25 wild-type and all 56 resistant or multidrug-resistant isolates. These PTs belonged to 41 different STs. Three major STs were identified: ST235 (including 13 isolates from hospital wastewater and WWTP); ST395 (including eight isolates from the various sampling points of the wastewater network) and ST253 (including six isolates from the river and the WWTP) (Figure 4). We determined the clonal relationship between STs by the MST method based on allelic profile [21]. Two allelic mismatches were allowed for group definition, as in group definition with eBURST. We represented the MST of the isolates with respect to their resistance profiles (Figure 3) or their origins (Figure 4). The 41 STs identified were distributed into 35 singletons (73 isolates) and two clonal complexes of six isolates (CC111, which included ST111 and ST966; and CC446, which included ST446 and ST296). The details of the STs (antibiotic resistance profile and origin) are provided in Table S1.


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)

Minimal spanning tree analysis of P. aeruginosa strains based on MLST data and isolation sites.
© Copyright Policy
Related In: Results  -  Collection

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

pone-0049300-g004: Minimal spanning tree analysis of P. aeruginosa strains based on MLST data and isolation sites.
Mentions: As PFGE typing is more discriminatory than MLST, we assumed that all the isolates with a given PT belonged to the same ST. We therefore determined the MLST profiles of the 54 PTs including at least one resistant or multi-resistant isolate. These 54 PTs included 81 isolates: 25 wild-type and all 56 resistant or multidrug-resistant isolates. These PTs belonged to 41 different STs. Three major STs were identified: ST235 (including 13 isolates from hospital wastewater and WWTP); ST395 (including eight isolates from the various sampling points of the wastewater network) and ST253 (including six isolates from the river and the WWTP) (Figure 4). We determined the clonal relationship between STs by the MST method based on allelic profile [21]. Two allelic mismatches were allowed for group definition, as in group definition with eBURST. We represented the MST of the isolates with respect to their resistance profiles (Figure 3) or their origins (Figure 4). The 41 STs identified were distributed into 35 singletons (73 isolates) and two clonal complexes of six isolates (CC111, which included ST111 and ST966; and CC446, which included ST446 and ST296). The details of the STs (antibiotic resistance profile and origin) are provided in Table S1.

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