Edward R.B. Moore
|Publicerad i||26th ECCMID 2016, 9 - 12 April 2016, Amsterdam, Netherlands|
Institutionen för biomedicin
Institutionen för biomedicin, avdelningen för infektionssjukdomar
Background: Microbial resistance to antibiotics is unfolding worldwide and this sets the treatment and control of infections at risk. Great concern has been directed towards the emergence of multi-resistant ESBL-producing E. coli (ESBL-E. coli). Certain virulent clones of ESBL- E. coli, such as O25b-ST131 clone (including the fimH30Rx–ST131 subclone), increasingly cause extra-intestinal infections and are of particular concern. Since they are greatly responsible for the global emerge of ESBL- E. coli, we compared the frequency of this clone to the other ESBL- E. coli types in patients with recurring urinary tract infections (UTI). Material/methods: Isolates from patients with repeated clinical UTIs due to ESBL-E. coli in Western Sweden from June 2008 to October 2010 were investigated. Patients with an initial UTI caused by ESBL-E. coli of O25b-ST131 clone (n=31) were compared with patients with ESBL-E.coli that tested negative for this clone (n=20). Presence of ESBL was confirmed with the double-disk diffusion test and with a multiplex PCR; PCR assays were used to detect the O25b-ST131 clone. In addition, the phylogenetic groups of E. coli strains were analysed and, for the non-O25b-ST131 isolates, PFGE-types were determined to verify possible strain identity. Results: For all patients in this study, the recurrent UTI was caused by the same E coli type as for the initial UTI, regardless of the E. coli strain type. Only one patient from non-O25b-ST131 group was infected by a different E. coli type, compared to the initial UTI isolate. All O25b-ST131 isolates belonged to the phylogenetic group, B2. The non-O25b-ST131 group was more heterogeneous; 36 % belonged to phylogenetic group A, 22 % to F, 16 % to B2, 10 % to D, 9 % to C and 7 % to group B1 and 21 distinct PFGE types were noted. The patients with previous O25b-ST131 infections exhibited a longer period of recurring infections. The maximum range of months was 25 for the O25b-ST131 group and 11 for the non-O25b-ST131, (mean: seven months versus four months, respectively) and almost twice as many episodes of UTI during the study period, compared to those caused by the non-O25b-ST131 isolates. Conclusions: Patients with recurring UTI caused by ESBL- E. coli were repeatedly infected with their initially isolated strain, which is of concern regarding those infected initially with E. coli O25b-ST131 isolates of known virulence potential. These patients also had more recurrences and for longer time-periods than those with UTI caused by other types. Further attention and consideration should be taken in patients infected by ESBL- E. coli of O25b-ST131 clone.