Pseudobacteremia with amoxycillin-clavulanic acid-resistant Escherichia coli traced to cross-contamination during blood culture processing.
Escherichia coli has seldom been reported to cause pseudobacteremia. The investigation of an outbreak of amoxycillin-clavulanic acid-resistant E. coli pseudobacteremia is described. Seventeen cases occurred over a five-day period. The source of the E. coli was traced to the blood culture specimen of a patient (index patient) with genuine bacteremia as a result of urinary tract infection. The other 16 case-patients had pseudobacteremia which was found to be the result of cross-contamination during subculture of blood specimens. The E. coli strain was carried over from the culture bottle of the index patient, through the contaminated gloved hands of a technician to the culture bottles of the other 16 cases. Although the pseudobacteremia occurred over a five-day period, they all resulted from cross-contamination during blood culture processing within one day. An early outbreak investigation was prompted by the unusual finding of amoxycillin-clavulanic acid resistance in the case E. coli isolates in a short period. The relatedness of the E. coli strains from the 17 cases was confirmed by arbitrary-primed polymerase chain reaction. Clinicians should be alerted to the possibility of a blood E. coli isolate being a contaminant despite its predominant role as a true pathogen.
Ho
P L
PL
Department of Microbiology, Faculty of Medicine, University of Hong Kong, Hong Kong, China.
Luk
W K
WK
Wong
S Y
SY
Seto
W H
WH
Lo
Y C
YC
Yuen
K Y
KY
D019980:Amoxicillin-Potassium Clavulanate Combination; D000668:Ampicillin Resistance; D016470:Bacteremia / Q000175:diagnosis*; D001431:Bacteriological Techniques; D003470:Culture Media; D003951:Diagnostic Errors; D004926:Escherichia coli / Q000254:growth & development / Q000302:isolation & purification
D003470:Culture Media; D019980:Amoxicillin-Potassium Clavulanate Combination