blaKPC and rmtB on a single plasmid in Enterobacter amnigenus and Klebsiella pneumoniae isolates from the same patient

• Published in: European journal of clinical microbiology & infectious diseases Vol. 31; no. 7; pp. 1585 - 1591
• Main Authors: Sheng, J.-F., Li, J.-J., Tu, S., Sheng, Z.-K., Bi, S., Zhu, M.-H., Shen, X.-M., Li, L.-J.
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer-Verlag 01-07-2012; Springer
• Subjects: Adult; Aged; Aged, 80 and over; Anti-Bacterial Agents - pharmacology; beta-Lactamases - genetics; Biological and medical sciences; Biomedical and Life Sciences; Biomedicine; Cluster Analysis; Drug Resistance, Multiple, Bacterial; Electrophoresis, Gel, Pulsed-Field; Enterobacter - drug effects; Enterobacter - genetics; Enterobacter - isolation & purification; Enterobacteriaceae Infections - microbiology; Female; Genes, Bacterial; Genotype; Humans; Infectious diseases; Internal Medicine; Klebsiella pneumoniae - drug effects; Klebsiella pneumoniae - genetics; Klebsiella pneumoniae - isolation & purification; Male; Medical Microbiology; Medical sciences; Methyltransferases - genetics; Middle Aged; Multilocus Sequence Typing; Plasmids - isolation & purification; Polymerase Chain Reaction; Single Plasmid; Enterobacter Amnigenus; Colistin; Tigecycline; Klebsiella Pneumoniae Carbapenemase; Human; Infection; Plasmid; Enterobacter; Microbiology; Bacteria; Klebsiella pneumoniae; Enterobacteriaceae
• ISSN: 0934-9723; 1435-4373
• DOI: 10.1007/s10096-011-1481-x

Enterobacter amnigenus
(EA76) and
Klebsiella pneumoniae
(KP76) isolates with multidrug-resistant (MDR) patterns were identified from the same patient in the neurosurgery department of our hospital. An outbreak of MDR
K. pneumoniae
had also occurred in this department. To characterize the resistance mechanism and molecular epidemiology of these isolates, sequential experiments including antimicrobial susceptibility testing, polymerase chain reaction (PCR), plasmid analysis, pulsed field gel electrophoresis (PFGE), and multilocus sequence typing (MLST) were performed. EA76 and KP76 were resistant to all of the antibiotics tested, except colistin and tigecycline.
bla
KPC-2
,
bla
TEM-1
,
bla
SHV-12
,
bla
CTX-M-3
,
bla
CTX-M-14
, and
rmtB
genes were identified in both isolates, with
bla
KPC-2
,
bla
TEM-1
,
bla
CTX-M-14
, and
rmtB
being co-carried on one plasmid in each isolate. Further analysis showed different restriction patterns between the two KPC-carrying plasmids. Of the 11 carbapenem-resistant isolates found in the outbreak, all were resistant to all of the β-lactams tested, with 63.64% (7/11) also exhibiting resistance to aminoglycosides and 72.73% (8/11) exhibiting resistance to quinolones. PCR analysis and molecular typing of the 11
K. pneumoniae
strains revealed that the seven aminoglycoside-resistant isolates shared the same antibiotic-resistant gene pattern and identical or one-band-difference PFGE profiles relative to KP76. In addition, all of the eight aminoglycoside-resistant isolates, including KP76, belonged to the national epidemic clone ST11. The overall results indicate the emergence of
E. amnigenus
and outbreak of ST11
K. pneumoniae
, with both co-harboring
bla
KPC
and
rmtB
genes on a single plasmid in our neurosurgery wards.