Faecal carriage of extended-spectrum β-lactamase-producing Enterobacteriaceae is common 12 months after infection and is related to strain factors.
We aimed to determine the duration of faecal carriage of extended-spectrum β-lactamase (ESBL) -producing Enterobacteriaceae (EPE) in patients with clinical infection caused by an EPE, to study host strains during carriage, and to identify factors associated with prolonged carriage. Patients (n = 61) were followed with faecal samples and questionnaires about antimicrobial treatment and risk factors for EPE, 1, 3, 6 and 12 months after EPE infection. The EPE isolates were subjected to ESBL genotyping, epidemiological typing with pulsed-field gel electrophoresis and PCR-based replicon typing. Escherichia coli isolates were analysed with PCR for phylogrouping, detection of pabB (ST131) and virulence content. Patient-related and strain-related variables were compared for carriers and non-carriers at 12 months. Carriage of EPE was observed in 51 of 61 (84%) patients after 1 month, 36 of 61 (66%) after 3 months, 31 of 61 (55%) after 6 months and 26 of 61 (43%) after 12 months. Of the 26 carriers at 12 months, five had previous negative samples. In 17 of 61 patients, ESBL was found in a new bacterial species and/or strain during carriage. Among E. coli, 14 of 49 belonged to the international clone ST131. Phylogroup B2 and CTX-M-gr.-9 were associated with being carriers at 12 months (OR 4.3, 95% CI 1.1-16.3 and OR 6.4, 95% CI 1.3-30.9, respectively). In conclusion, EPE carriage is common 12 months after infection and persisting carriage may be associated with E. coli phylogroup B2 and CTX-M-gr.-9. The host strain frequently changes throughout carriage and negative samples do not imply eliminated carriage.
Department of Infectious Diseases, Division of Medicine, Karolinska University Hospital, Huddinge, Stockholm, Sweden; Clinical Microbiology, Karolinska Institutet - MTC, Karolinska University Hospital, Solna, Stockholm, Sweden.
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Titelman
C M
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Hasan
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Iversen
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Nauclér
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Kais
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Kalin
C G
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Giske
D000900:Anti-Bacterial Agents / Q000627:therapeutic use; D002353:Carrier State / Q000453:epidemiology* / Q000382:microbiology; D015331:Cohort Studies; D004269:DNA, Bacterial / Q000235:genetics; D004755:Enterobacteriaceae / Q000145:classification / Q000201:enzymology* / Q000235:genetics / Q000302:isolation & purification; D004756:Enterobacteriaceae Infections / Q000453:epidemiology* / Q000382:microbiology; D005243:Feces / Q000382:microbiology*; D005260:Female; D005838:Genotype; D006801:Humans; D008297:Male; D008875:Middle Aged; D058889:Molecular Typing; D011446:Prospective Studies; D011795:Surveys and Questionnaires; D013997:Time Factors; D001618:beta-Lactamases / Q000378:metabolism*
D000900:Anti-Bacterial Agents; D004269:DNA, Bacterial; D001618:beta-Lactamases
CTX-M-15; ST131; extended-spectrum β-lactamase; phylogroup B2; stool colonization