CTX-M-producing Escherichia coli in a maternity ward: a likely community importation and evidence of mother-to-neonate transmission.
OBJECTIVE
To investigate the high prevalence of extended-spectrum beta-lactamase (ESBL)-producing strains of Escherichia coli (4%, 10/250 consecutive isolates) recovered during a 5 month period in the maternity ward of the University Hospital of Bordeaux, France.


METHODS
beta-Lactam resistance transfer was analysed by conjugation and transformation. ESBLs were characterized by isoelectric focusing, PCR amplification and sequencing. The relatedness of the strains was examined by PFGE and phylogenetic group determination. Plasmids were characterized by incompatibility group and restriction analysis.


RESULTS
Ten ESBL-producing E. coli were isolated from urinary or genital samples of eight mothers and from gastric fluids of two newborns of carrier mothers. The patients were hospitalized in five different units of the maternity ward. Transconjugants, obtained for 7 of the 10 strains, and wild-type strains exhibited various antibiotypes. Different CTX-M enzymes were characterized: CTX-M-1 (n = 4); CTX-M-14 (n = 3); CTX-M-32 (n = 2); and CTX-M-28 (n = 1). The strains recovered from two mothers and their respective babies were identical. All the other strains were epidemiologically unrelated. Furthermore, various plasmids were identified. Environmental samples from the common echographic and sampling rooms did not reveal the presence of ESBL-producing enterobacteria.


CONCLUSIONS
The data argue against the occurrence of a nosocomial outbreak and support the hypothesis of an importation of community-acquired ESBL-producing strains into the hospital through colonized/infected patients. At present, not only patients transferred from other hospitals or long-term care facilities are at risk of carrying ESBL-producing enterobacteria on hospital admission, but also community patients.
Dubois
Véronique
V
UMR 5234, CNRS, 33076 Bordeaux, France. veronique.dubois@bacterio.u-bordeaux2.f
De Barbeyrac
Bertille
B
Rogues
Anne-Marie
AM
Arpin
Corinne
C
Coulange
Laure
L
Andre
Catherine
C
M'zali
Fatima
F
Megraud
Francis
F
Quentin
Claudine
C
D000328:Adult; D000900:Anti-Bacterial Agents / Q000494:pharmacology; D015373:Bacterial Typing Techniques; D017714:Community-Acquired Infections / Q000453:epidemiology / Q000382:microbiology / Q000635:transmission; D016172:DNA Fingerprinting; D016521:Electrophoresis, Gel, Pulsed-Field; D004783:Environmental Microbiology; D004926:Escherichia coli / Q000145:classification / Q000187:drug effects / Q000201:enzymology* / Q000302:isolation & purification; D004927:Escherichia coli Infections / Q000453:epidemiology / Q000382:microbiology* / Q000635:transmission*; D029968:Escherichia coli Proteins / Q000096:biosynthesis*; D005260:Female; D005602:France / Q000453:epidemiology; D005838:Genotype; D006771:Hospitals, Maternity; D006785:Hospitals, University; D006801:Humans; D007231:Infant, Newborn; D018445:Infectious Disease Transmission, Vertical; D008826:Microbial Sensitivity Tests; D010957:Plasmids / Q000032:analysis; D011247:Pregnancy; D001618:beta-Lactamases / Q000096:biosynthesis* / Q000145:classification; D047090:beta-Lactams / Q000494:pharmacology
D000900:Anti-Bacterial Agents; D029968:Escherichia coli Proteins; D047090:beta-Lactams; D001618:beta-Lactamases