Emergence of multidrug-resistant Gram-negative bacteria during selective decontamination of the digestive tract on an intensive care unit.
OBJECTIVE
During treatment with selective decontamination of the digestive tract (SDD), four multidrug-resistant (MDR) strains, three different Escherichia coli and one Klebsiella pneumoniae, were isolated from four patients not known as carriers of such MDR strains before their admission to the intensive care unit (ICU) in the Academic Medical Center (AMC) in Amsterdam. These isolates were extended-spectrum beta-lactamase (ESBL)-positive. We investigated whether this was due to interspecies transfer of resistance genes.


METHODS
The MDR strains were typed by amplified fragment length polymorphism (AFLP) analysis. The plasmids from these strains were characterized by restriction fragment length polymorphism and the resistance genes were characterized by PCR and sequence analysis.


RESULTS
The strains were genetically unrelated and contained identical plasmids with ESBL genes.


CONCLUSIONS
We identified an outbreak of plasmid-mediated ESBL genes during SDD treatment in the ICU. The use of third-generation cephalosporins in SDD is associated with the emergence of ESBLs. We conclude that identification of emerging MDR Gram-negative bacteria and recognition of resistance plasmid transfer during SDD treatment are crucial for optimal application of this regimen in ICUs.
Al Naiemi
Nashwan
N
Academic Medical Center, Department of Medical Microbiology Amsterdam, The Netherlands.
Heddema
Edou R
ER
Bart
Aldert
A
de Jonge
Evert
E
Vandenbroucke-Grauls
Christina M
CM
Savelkoul
Paul H M
PH
Duim
Birgitta
B
D000900:Anti-Bacterial Agents / Q000008:administration & dosage / Q000494:pharmacology; D003666:Decontamination / Q000379:methods*; D004064:Digestive System / Q000187:drug effects* / Q000382:microbiology; D024901:Drug Resistance, Multiple, Bacterial; D004926:Escherichia coli / Q000145:classification / Q000187:drug effects* / Q000302:isolation & purification; D006090:Gram-Negative Bacteria / Q000187:drug effects / Q000201:enzymology / Q000302:isolation & purification; D006801:Humans; D007362:Intensive Care Units; D007711:Klebsiella pneumoniae / Q000145:classification / Q000187:drug effects* / Q000302:isolation & purification; D008826:Microbial Sensitivity Tests; D010957:Plasmids / Q000235:genetics; D016133:Polymerase Chain Reaction; D012150:Polymorphism, Restriction Fragment Length; D017422:Sequence Analysis, DNA; D001618:beta-Lactamases / Q000235:genetics
D000900:Anti-Bacterial Agents; D001618:beta-Lactamases