JOURNAL ARTICLE

Co-production of SFO-1 and DHA-1 β-lactamases and 16S rRNA methylase ArmA in clinical isolates of Klebsiella pneumoniae

Qinglan Guo, Peng Wang, Ying Ma, Yang Yang, Xinyu Ye, Minggui Wang
Journal of Antimicrobial Chemotherapy 2012, 67 (10): 2361-6
22778158

OBJECTIVES: To investigate the epidemiology and genetic characteristics of the plasmid-mediated extended-spectrum β-lactamase (ESBL) gene bla(SFO-1) in clinical isolates of ESBL-producing Klebsiella pneumoniae and Escherichia coli.

METHODS: The prevalence of the bla(SFO-1) gene was examined by PCR amplification. Conjugation and transformation experiments were performed and the presence of antimicrobial resistance determinants was investigated by the PCR method. The genetic environments of the bla(SFO-1) and armA genes were determined by direct sequencing of plasmid pHS20. Plasmids were typed by PCR-based replicon typing. PFGE and multilocus sequence typing were performed on SFO-producing strains.

RESULTS: Of 158 ESBL-producing strains of K. pneumoniae, 3 (1.9%) carried the bla(SFO-1) gene. All of the SFO-producing isolates belonged to the ST11 epidemic clone, with a single PFGE type and had high-level resistance to third-generation cephalosporins, aminoglycosides and ciprofloxacin. The bla(SFO-1) gene was co-transferred with the armA, aac(6')-Ib-cr and bla(TEM-1) genes by transformation, whereas the armA, bla(DHA-1) and qnrB4 genes were co-transferred by conjugation. The armA genes were located within the composite transposon Tn1548 on two different plasmids in the strain 08-129. The bla(SFO-1) gene was located upstream of an ampR gene from the coding region and flanked by two inverted repeats of IS26. Plasmids carrying bla(DHA-1) were identified as IncFII, while the bla(SFO-1)-bearing plasmids were non-typeable.

CONCLUSIONS: Although SFO-1 is a low-occurrence ESBL, it has been captured by a plasmid accumulating multiple resistance determinants including armA and aac(6')-Ib-cr, and accompanied by a large DHA-1-bearing IncFII plasmid in a prevalent K. pneumoniae ST11 clone.

Full Text Links

Find Full Text Links for this Article

Discussion

You are not logged in. Sign Up or Log In to join the discussion.

Related Papers

Remove bar
Read by QxMD icon Read
22778158
×

Save your favorite articles in one place with a free QxMD account.

×

Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"