Development of highly ciprofloxacin-resistant laboratory mutants of Acinetobacter baumannii lacking topoisomerase IV gene mutations

description. To our knowledge, this is also the first report of group 2 CTX-M enzymes in the UK; the isolates were from three hospitals and it is possible that they represent separate introductions. Group 2 are the most prevalent CTX-M enzymes in parts of South America and in Israel; group 9 enzymes are prevalent in Spain. In summary, we have developed a multiplex PCR assay that was able to detect and distinguish alleles encoding CTX-M enzymes belonging to all five phylogenetic groups. CTX-M ESBLs are recognized worldwide as an increasingly serious public health concern. Simple PCR assays, as described here and by others, will assist in monitoring their emergence and dissemination.