During a large hospital outbreak of OXA-48 producing bacteria, most K. pneumoniaeOXA-48 isolates were phenotypically resistant to meropenem or imipenem, whereas most E. coliOXA-48 isolates were phenotypically susceptible to these antibiotics. In the absence of molecular gene-detection E. coliOXA-48 could remain undetected, facilitating cross-transmission and horizontal gene transfer of blaOXA-48. Based on 868 longitudinal molecular microbiological screening results from patients carrying K. pneumoniaeOXA-48 (n = 24), E. coliOXA-48 (n = 17), or both (n = 40) and mathematical modelling we determined mean durations of colonisation (278 and 225 days for K. pneumoniaeOXA-48 and E. coliOXA-48, respectively), and horizontal gene transfer rates (0.0091/day from K. pneumoniae to E. coli and 0.0015/day vice versa). Based on these findings the maximum effect of horizontal gene transfer of blaOXA-48 originating from E. coliOXA-48 on the basic reproduction number (R0) is 1.9%, and it is, therefore, unlikely that phenotypically susceptible E. coliOXA-48 will contribute significantly to the spread of blaOXA-48. Copyright:

dx.doi.org/10.1371/journal.pone.0140960, hdl.handle.net/1765/91487

Haverkate, M.R, Dautzenberg, M.J.D, Ossewaarde, T.M, van der Zee, A, Den Hollander, J.G, Troelstra, A, … Bootsma, M. (2015). Within-host and population transmission of blaOXA-48 in K. pneumoniae and E. coli. PLoS ONE, 10(10). doi:10.1371/journal.pone.0140960