Extended-Spectrum β-Lactamase- and plasmid AmpC- producing Escherichia coli causing community-onset bloodstream infection: the association of bacterial clones and virulence genes with septic shock, source of infection and recurrencies.

Fröding I, Hasan B, Sylvin I, Coorens M, Nauclér P, Giske CG

Antimicrob. Agents Chemother. - (-) - [2020-05-18; online 2020-05-18]

Invasive infections due to extended-spectrum β-lactamase- and pAmpC-producing Escherichia coli (ESBL/pAmpC-EC) are an important cause of morbidity, often caused by the high-risk clone ST131 and isolates classified as extra-intestinal pathogenic E. coli (ExPEC). The relative influence of host immunocompetence versus microbiological virulence factors in the acquisition and outcome of bloodstream infections (BSI) is poorly understood. Herein, we used whole genome sequencing on 278 blood culture isolates of ESBL/pAmpC-EC from 260 patients with community-onset BSI collected during 2012-2015 in Stockholm, to study the association of virulence genes, sequence types and antimicrobial resistance with severity of disease, infection source, ESBL/pAmpC-EC BSI low-risk patients and patients with repeated episodes.ST131 subclade C2 comprised 29% of all patients. Factors associated with septic shock in multivariable analysis were patient host factors (hematologic cancer or transplantation and reduced daily living activity), presence of the E. coli virulence factor iss (increased serum survival), absence of phenotypic multidrug-resistance and absence of the genes pap and hsp Adhesins, particularly pap, were associated with urinary tract infection (UTI) source, while isolates from post-prostate biopsy sepsis had low overall number of virulence operons, including adhesins, and commonly belonged to ST131 clades A, B and subclade C1, ST1193, and ST648. ST131 was associated with recurrent episodes. In conclusion, the most interesting finding is the association of iss with septic shock. Adhesins are important for UTI pathogenesis, while otherwise low-pathogenic isolates from the microbiota can cause post-prostate biopsy sepsis.

Clinical Genomics Stockholm [Service]

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PubMed 32423949

DOI 10.1128/AAC.02351-19

Crossref 10.1128/AAC.02351-19

pii: AAC.02351-19