Preliminary Study of Randomly-Amplified Polymorphic DNA Analysis for Typing Extended-Spectrum Beta-Lactamase (ESBL)-Producing Klebsiella pneumoniae
Chanwit Tribuddharat MD, PhD*, Somporn Srifuengfung PhD*, Wararat Chiangjong MSc*
Affiliation : * Department of Microbiology, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok
Objective : Extended-spectrum beta-lactamases (ESBLs) are most prevalent in Klebsiella pneumoniae. This
organism is frequently isolated from clinical specimens and can cause septicemia, pneumonia or urinary tract
infection. There were occasionally suspicious outbreaks of ESBL-producing K. pneumoniae in patients’ wards.
The objective is to determine whether the randomly amplified polymorphic DNA (RAPD), which is a polymerase
chain reaction (PCR)-based typing technique, can be used as a typing method for studying the molecular
epidemiology of ESBL-producing K. pneumoniae.
Material and Method: The present study was carried out by using 30 ESBL-producing K. pneumoniae isolates
obtained from different patients admitted to Siriraj Hospital between January and February 2004. RAPD was
evaluated for three primers. All isolates were re-examined by using Southern blot hybridization.
Results : It was found that 29 DNA band patterns were generated individually by either AP4 or HLWL74 and
R108 primers (30 patterns) for RAPD analysis and 30 patterns for Southern blot hybridization with class 1
integron (intI1) probe. Different patterns indicated that these 30 isolates could not be the cause of an outbreak
in Siriraj Hospital.
Conclusion : The RAPD typing is good and can be used as a screening, rapid and inexpensive test for ESBL-
producing K. pneumoniae during investigation of outbreaks.
Keywords : Klebsiella pneumoniae, Extended-spectrum beta-lactamase, ESBL, Randomly amplified polymorphic DNA, RAPD
