Prolonged carriage of resistant E. coli by returned travellers: clonality, risk factors and bacterial characteristics
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The aim of this study was to delineate the potential risks and dynamics of the prolonged carriage of resistant E. coli in returned travellers. A sample of 274 previously collected E. coli resistant to ceftriaxone (CRO), ciprofloxacin, gentamicin and/or nalidixic acid recovered from 102 travellers was studied. Travellers were assessed pre-travel then longitudinally (maximum 6 months) with peri-rectal/rectal swabs. Clonality was determined by REP-PCR and the presence of O25b-ST131 was assessed. Comparison was made longitudinally for individuals and between identified co-travellers. The risk of prolonged carriage was lower for CRO than for ciprofloxacin or gentamicin resistance. Repeated isolation of the same phenotype at different time points occurred in 19% of initial CRO-resistant carriers compared with 50% of ciprofloxacin- or gentamicin-resistant carriers. The duration of carriage was also longer for the latter resistance phenotypes (75th quartile 8 vs 62 and 63 days respectively). In multivariate analysis, risks of prolonged carriage included antimicrobial use whilst travelling (3.3, 1.3–8.4) and phylogenetic group B2 (9.3, 3.4–25.6) and D (3.8, 1.6–8.8). Clonality amongst longitudinal isolates from the same participant was demonstrated in 92% of participants who were assessable and most marked amongst CRO-resistant isolates. ST-131 was surprisingly infrequent (3% of participants). Prolonged carriage of ciprofloxacin- and gentamicin-resistant isolates is more frequent and prolonged than CRO resistance after travel. Risks of prolonged carriage indicate a contribution of host and bacterial factors to this carriage. These require further elucidation. The strong clonality identified suggests that carriage of a “phenotype” was mediated by persistence of bacteria/plasmid combinations rather than persistence of the plasmid after horizontal transfer to other bacteria.
KeywordsCeftriaxone Phylogenetic Group Resistant Isolate AmpC Accelerate Failure Time Model
Thank you to Prof. Mark Schembri for his review of this manuscript.
Conflict of interests
BR, KK, HS, MJ and DP declare that they have no conflicts of interest.
- 7.Lautenbach E, Tolomeo P, Mao X, Fishman NO, Metlay JP, Bilker WB, Nachamkin I (2006) Duration of outpatient fecal colonization due to Escherichia coli isolates with decreased susceptibility to fluoroquinolones: longitudinal study of patients recently discharged from the hospital. Antimicrob Agents Chemother 50(11):3939–3943PubMedCrossRefGoogle Scholar
- 8.Horcajada JP, Vila J, Moreno-Martinez A, Ruiz J, Martinez JA, Sanchez M, Soriano E, Mensa J (2002) Molecular epidemiology and evolution of resistance to quinolones in Escherichia coli after prolonged administration of ciprofloxacin in patients with prostatitis. J Antimicrob Chemother 49(1):55–59PubMedCrossRefGoogle Scholar
- 9.Weintrob AC, Roediger MP, Barber M, Summers A, Fieberg AM, Dunn J, Seldon V, Leach F, Huang XZ, Nikolich MP, Wortmann GW (2010) Natural history of colonization with gram-negative multidrug-resistant organisms among hospitalized patients. Infect Control Hosp Epidemiol 31(4):330–337PubMedCrossRefGoogle Scholar
- 15.Clermont O, Dhanji H, Upton M, Gibreel T, Fox A, Boyd D, Mulvey MR, Nordmann P, Ruppe E, Sarthou JL, Frank T, Vimont S, Arlet G, Branger C, Woodford N, Denamur E (2009) Rapid detection of the O25b-ST131 clone of Escherichia coli encompassing the CTX-M-15-producing strains. J Antimicrob Chemother 64(2):274–277PubMedCrossRefGoogle Scholar
- 16.Rodriguez-Bano J, Navarro MD, Romero L, Martinez-Martinez L, Muniain MA, Perea EJ, Perez-Cano R, Pascual A (2004) Epidemiology and clinical features of infections caused by extended-spectrum beta-lactamase-producing Escherichia coli in nonhospitalized patients. J Clin Microbiol 42(3):1089–1094PubMedCrossRefGoogle Scholar
- 19.Gupta K, Hooton TM, Naber KG, Wullt B, Colgan R, Miller LG, Moran GJ, Nicolle LE, Raz R, Schaeffer AJ, Soper DE (2011) International clinical practice guidelines for the treatment of acute uncomplicated cystitis and pyelonephritis in women: a 2010 update by the Infectious Diseases Society of America and the European Society for Microbiology and Infectious Diseases. Clin Infect Dis 52(5):e103–e120PubMedCrossRefGoogle Scholar
- 20.Antibiotic Expert Group, Spicer J, Therapeutic Guidelines Limited (2010) Therapeutic guidelines: antibiotic. Therapeutic Guidelines, Melbourne, p xxxiv, 445Google Scholar