2 research outputs found
Extended-spectrum beta-lactamases in ceftazidime-resistant Escherichia coli and Klebsiella pneumoniae isolates in Turkish hospitals
Purpose: To study the prevalence of TEM-, SHV- and GES-type β
-lactamases among Escherichia coli and Klebsiella pneumoniae
strains having ceftazidime MICs higher than 2 mg/L. Methods: A total
of 63 E. coli and 41 K. pneumoniae isolated from five different
university hospitals were studied for the existence of TEM-, SHV- and
GES-type β -lactamases. Susceptibility tests were carried out
according to the criteria of National Committee for Clinical Laboratory
Standards. MICs were obtained by agar dilution method. Existence of
extended-spectrum β -lactamases (ESBLs) were assessed by
double-disc synergy test (DDST). Existence of the above-mentioned
β -lactamase genes were studied both by PCR with specific
oligonucleotide primers and isoelectric focusing methods. Results:
None of the isolates were carbapenem-resistant. DDSTs were positive in
50 (79.3%) and 33 (80.5%) of E. coli and K. pneumoniae ,
respectively. TEM gene was detected in 41 (65.1%) and 19 (46.3%),
whereas SHV gene in 18 (28.6%) and 20 (48.8%) of E. coli and K.
pneumoniae strains, respectively. GES genes were not detected.
Conclusions: TEM and SHV genes are highly prevalent among
ESBL-producing E. coli and K. pneumoniae , whereas GES-type ESBLs are
absent and found not to be responsible of ceftazidime resistance in
Turkish hospitals