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Isolation and Characterization of NDM-Positive Escherichia coli from Municipal Wastewater in Jeddah, Saudi Arabia

View Article: PubMed Central - PubMed

ABSTRACT

The emergence of resistance to last-resort antibiotics is a public health concern of global scale. Besides direct person-to-person propagation, environmental pathways might contribute to the dissemination of antibiotic-resistant bacteria and antibiotic resistance genes (ARGs). Here, we describe the incidence of blaNDM-1, a gene conferring resistance to carbapenems, in the wastewater of the city of Jeddah, Saudi Arabia, over a 1-year period. blaNDM-1 was detected at concentrations ranging from 104 to 105 copies/m3 of untreated wastewater during the entire monitoring period. These results indicate the ubiquity and high incidence of blaNDM-1 in the local wastewater. To track the bacteria carrying blaNDM-1, we isolated Escherichia coli PI7, a strain of sequence type 101 (ST101), from wastewater around the Hajj event in October 2013. Genome sequencing of this strain revealed an extensive repertoire of ARGs as well as virulence and invasive traits. These traits were further confirmed by antibiotic resistance profiling and in vitro cell internalization in HeLa cell cultures. Given that this strain remains viable even after a certain duration in the sewerage, and that Jeddah lacks a robust sanitary infrastructure to fully capture all generated sewage, the presence of this bacterium in the untreated wastewater represents a potential hazard to the local public health. To the best of our knowledge, this is the first report of a blaNDM-1-positive E. coli strain isolated from a nonnosocomial environment in Saudi Arabia and may set a priority concern for the need to establish improved surveillance for carbapenem-resistant E. coli in the country and nearby regions.

No MeSH data available.


Genetic map of the plasmid carrying blaNDM-1 in E. coli PI7 (pKOX_NDM1) and contigs mapping against pKOX_R1 of Klebsiella oxytoca. Relevant characteristics related to antimicrobial resistance (orange), metal resistance (light blue), mobilization elements (purple), and plasmid maintenance and stability (green) are highlighted in the map. (a) pKOX_NDM1 was fully sequenced in this study and shares 99% sequence identity with the reported sequence for K. oxytoca (18). (b) pKOX_R1 was drawn based on the reported sequence for K. oxytoca (18). The inner green circle in the pKOX_R1 map represents the coverage of the contigs in this study mapping against pKOX_R1. Genes highlighted in red type represent those encoding relevant traits mapping outside the contigs found in this study.
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Figure 2: Genetic map of the plasmid carrying blaNDM-1 in E. coli PI7 (pKOX_NDM1) and contigs mapping against pKOX_R1 of Klebsiella oxytoca. Relevant characteristics related to antimicrobial resistance (orange), metal resistance (light blue), mobilization elements (purple), and plasmid maintenance and stability (green) are highlighted in the map. (a) pKOX_NDM1 was fully sequenced in this study and shares 99% sequence identity with the reported sequence for K. oxytoca (18). (b) pKOX_R1 was drawn based on the reported sequence for K. oxytoca (18). The inner green circle in the pKOX_R1 map represents the coverage of the contigs in this study mapping against pKOX_R1. Genes highlighted in red type represent those encoding relevant traits mapping outside the contigs found in this study.

Mentions: The E. coli PI7 genome is 4.6 Mb in size and has an average GC content of 50.85%. It harbors 108 noncoding RNAs (ncRNAs) and 4,320 open-reading frames (ORFs) corresponding to 842 and 3,478 hypothetical and nonhypothetical proteins, respectively. MLST analysis based on seven housekeeping genes on the chromosomal genome revealed that E. coli PI7 belongs to ST101. Besides the chromosomal genome, E. coli PI7 also carries one plasmid of 110 kb from the IncF incompatibility group and a secondary IncA/C plasmid that was partially identified (Fig. 2). The IncF plasmid shared high similarity (>97%) with Klebsiella oxytoca pKOX_NDM, while the other plasmid in E. coli PI7 contains contigs that showed high BLAST hit scores with pKOX_R1 of Klebsiella oxytoca (18).


Isolation and Characterization of NDM-Positive Escherichia coli from Municipal Wastewater in Jeddah, Saudi Arabia
Genetic map of the plasmid carrying blaNDM-1 in E. coli PI7 (pKOX_NDM1) and contigs mapping against pKOX_R1 of Klebsiella oxytoca. Relevant characteristics related to antimicrobial resistance (orange), metal resistance (light blue), mobilization elements (purple), and plasmid maintenance and stability (green) are highlighted in the map. (a) pKOX_NDM1 was fully sequenced in this study and shares 99% sequence identity with the reported sequence for K. oxytoca (18). (b) pKOX_R1 was drawn based on the reported sequence for K. oxytoca (18). The inner green circle in the pKOX_R1 map represents the coverage of the contigs in this study mapping against pKOX_R1. Genes highlighted in red type represent those encoding relevant traits mapping outside the contigs found in this study.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4997845&req=5

Figure 2: Genetic map of the plasmid carrying blaNDM-1 in E. coli PI7 (pKOX_NDM1) and contigs mapping against pKOX_R1 of Klebsiella oxytoca. Relevant characteristics related to antimicrobial resistance (orange), metal resistance (light blue), mobilization elements (purple), and plasmid maintenance and stability (green) are highlighted in the map. (a) pKOX_NDM1 was fully sequenced in this study and shares 99% sequence identity with the reported sequence for K. oxytoca (18). (b) pKOX_R1 was drawn based on the reported sequence for K. oxytoca (18). The inner green circle in the pKOX_R1 map represents the coverage of the contigs in this study mapping against pKOX_R1. Genes highlighted in red type represent those encoding relevant traits mapping outside the contigs found in this study.
Mentions: The E. coli PI7 genome is 4.6 Mb in size and has an average GC content of 50.85%. It harbors 108 noncoding RNAs (ncRNAs) and 4,320 open-reading frames (ORFs) corresponding to 842 and 3,478 hypothetical and nonhypothetical proteins, respectively. MLST analysis based on seven housekeeping genes on the chromosomal genome revealed that E. coli PI7 belongs to ST101. Besides the chromosomal genome, E. coli PI7 also carries one plasmid of 110 kb from the IncF incompatibility group and a secondary IncA/C plasmid that was partially identified (Fig. 2). The IncF plasmid shared high similarity (>97%) with Klebsiella oxytoca pKOX_NDM, while the other plasmid in E. coli PI7 contains contigs that showed high BLAST hit scores with pKOX_R1 of Klebsiella oxytoca (18).

View Article: PubMed Central - PubMed

ABSTRACT

The emergence of resistance to last-resort antibiotics is a public health concern of global scale. Besides direct person-to-person propagation, environmental pathways might contribute to the dissemination of antibiotic-resistant bacteria and antibiotic resistance genes (ARGs). Here, we describe the incidence of blaNDM-1, a gene conferring resistance to carbapenems, in the wastewater of the city of Jeddah, Saudi Arabia, over a 1-year period. blaNDM-1 was detected at concentrations ranging from 104 to 105 copies/m3 of untreated wastewater during the entire monitoring period. These results indicate the ubiquity and high incidence of blaNDM-1 in the local wastewater. To track the bacteria carrying blaNDM-1, we isolated Escherichia coli PI7, a strain of sequence type 101 (ST101), from wastewater around the Hajj event in October 2013. Genome sequencing of this strain revealed an extensive repertoire of ARGs as well as virulence and invasive traits. These traits were further confirmed by antibiotic resistance profiling and in vitro cell internalization in HeLa cell cultures. Given that this strain remains viable even after a certain duration in the sewerage, and that Jeddah lacks a robust sanitary infrastructure to fully capture all generated sewage, the presence of this bacterium in the untreated wastewater represents a potential hazard to the local public health. To the best of our knowledge, this is the first report of a blaNDM-1-positive E. coli strain isolated from a nonnosocomial environment in Saudi Arabia and may set a priority concern for the need to establish improved surveillance for carbapenem-resistant E. coli in the country and nearby regions.

No MeSH data available.