SHV-34: an extended-spectrum beta-lactamase encoded by an epidemic plasmid.
OBJECTIVE
To elucidate the causes for treatment failure in children given extended-spectrum cephalosporins.


METHODS
During April 1998-March 2000, 18 isolates of members of the family Enterobacteriaceae, fulfilling microbiological criteria for carriage of extended-spectrum beta-lactamases (ESBLs) and carrying blaSHV, were isolated from paediatric inpatients. The collection was subjected to a retrospective molecular analysis.


RESULTS
Three species were represented in the collection: Citrobacter koseri (one isolate), Escherichia coli (one isolate) and Klebsiella pneumoniae (16 isolates). A common plasmid was found in these bacteria, as judged by restriction endonuclease digestion. This was able to transfer an ESBL phenotype from donors to a laboratory strain of E. coli. Nucleotide sequence analysis revealed that this phenotype was associated with a new variant in blaSHV encoding SHV-34.


CONCLUSIONS
Analysis reveals the presence of an epidemic plasmid in this collection of bacteria. This carries a gene encoding the SHV-34 ESBL, described for the first time in this report. Nucleotide sequence analysis shows that there is a mutation from A-->G affecting the codon at amino acid position 64 (GAA-->GGA), changing the glutamic acid typically seen in this position to glycine.
Heritage
John
J
Division of Microbiology, School of Biochemistry and Molecular Biology, University of Leeds, Leeds LS2 9JT, UK. j.heritage@leeds.ac.uk
Chambers
Philip A
PA
Tyndall
Caroline
C
Buescher
E Stephen
ES
D019943:Amino Acid Substitution; D002511:Cephalosporins / Q000627:therapeutic use; D002648:Child; D041041:Citrobacter koseri / Q000187:drug effects / Q000235:genetics; D003227:Conjugation, Genetic; D004755:Enterobacteriaceae / Q000187:drug effects / Q000235:genetics*; D004756:Enterobacteriaceae Infections / Q000188:drug therapy / Q000453:epidemiology* / Q000382:microbiology; D004926:Escherichia coli / Q000187:drug effects / Q000235:genetics; D029968:Escherichia coli Proteins / Q000235:genetics*; D006801:Humans; D007711:Klebsiella pneumoniae / Q000187:drug effects / Q000235:genetics; D008826:Microbial Sensitivity Tests; D010641:Phenotype; D010957:Plasmids / Q000235:genetics*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D017211:Treatment Failure; D001618:beta-Lactamases / Q000235:genetics*
D002511:Cephalosporins; D029968:Escherichia coli Proteins; D001618:beta-Lactamases; C487458:beta-lactamase SHV-34, E coli