A novel functional class 2 integron in clinical Proteus mirabilis isolates.
OBJECTIVES
To describe a novel functional class 2 integron that was found in clinical Proteus mirabilis isolates.


METHODS
Class 1 and 2 integrons were screened by PCR in 153 clinical Proteus isolates. The variable regions of class 1 and 2 integrons were determined by restriction analysis and sequencing. The mutations of internal stop codons in class 2 integrons and their common promoters were also determined by sequencing. Enterobacterial repetitive intergenic consensus (ERIC)-PCR was used to analyse the phylogenetic relations of class 2 integron-positive P. mirabilis isolates.


RESULTS
Class 1 integrons were detected in 96 (63%) of 153 Proteus isolates: eight different gene cassette arrays were detected, including dfrA32-ereA1-aadA2, which was detected for the first time in P. mirabilis. Class 2 integrons were detected in 101 (66%) of 153 Proteus isolates: four different gene cassette arrays were detected, including dfrA1-catB2-sat2-aadA1, which was detected for the first time in a class 2 integron. A novel functional class 2 integron was detected in 38 P. mirabilis isolates with a common promoter (-35 TTTAAT|16 bp|-10 TAAAGT). The variable region of this functional class 2 integron contained dfrA14 and three novel open reading frames with unknown functions. Very similar ERIC-PCR fingerprinting patterns were detected in these 38 P. mirabilis isolates and were different from other class 2 integron-positive isolates.


CONCLUSIONS
A novel functional class 2 integron was found for the first time in P. mirabilis. These functional class 2 integron-harbouring P. mirabilis isolates were likely to be clonally spread in our hospital.
['Wei|Quhao|Q|', 'Hu|Qingfeng|Q|', 'Li|Shanshan|S|', 'Lu|Huoyang|H|', 'Chen|Guoqiang|G|', 'Shen|Beiqiong|B|', 'Zhang|Ping|P|', 'Zhou|Yonglie|Y|']
D018388:Codon, Terminator D004269:DNA, Bacterial D005838:Genotype D006801:Humans D032023:Integrons D008969:Molecular Sequence Data D058889:Molecular Typing D010802:Phylogeny D016133:Polymerase Chain Reaction D012150:Polymorphism, Restriction Fragment Length D011401:Promoter Regions, Genetic D011512:Proteus Infections D011513:Proteus mirabilis D017422:Sequence Analysis, DNA
gene cassettes horizontal gene transfer integrases recombination