Outbreaks caused by Enterobacteriaceae isolates producing extended-spectrum ␤-lactamases (ESBL) in neonatal wards can be difficult to control. We report here an extensive outbreak in a neonatal ward with a case of meningitis caused by an ESBL-producing Escherichia coli strain. Between 24 March and 29 April 2009, among the 59 neonates present in the ward, 26 neonates with ESBL-producing E. coli rectal colonization were detected (44%). One of the colonized neonates developed meningitis with a favorable outcome after treatment combining imipenem, gentamicin, and ciprofloxacin. Despite strict intensification of hygiene and isolation procedures for more than 1 month, ward closure to new admissions was necessary to control the outbreak. Randomly amplified polymorphic DNA and pulsed-field gel electrophoresis analysis performed on 31 isolates recovered from 26 neonates and two mother's milk samples showed a clonal strain. ESBL PCR assays indicated that the strain harbored a TEM-52 ESBL encoded by an IncI1 replicon. Phylogenetic analysis by multilocus sequence typing showed that the strain belonged to rare phylogenetic group C, which is closely related to group B1 but appears as group A by the triplex PCR phylogrouping method. The strain harbored the virulence genes fuyA, aer, and iroN and was virulent in a mouse model of septicemia. This work indicates the high potential of colonization, transmission, and virulence of some ESBL-producing E. coli clones.With Streptococcus agalactiae, Escherichia coli is one of the two most common bacterial species frequently responsible of neonatal infections (34). E. coli is the second leading cause of neonatal bacterial meningitis in industrial countries, and recent studies suggest that extraintestinal pathogenic E. coli isolates belong mainly to phylogenetic group B2 (2, 6). An increased rate of E. coli ampicillin resistance after the initiation of intrapartum antimicrobial prophylaxis was previously reported (5, 34). However, most of the E. coli isolates remained susceptible to extended-spectrum cephalosporins (ESC), but currently, extended-spectrum ␤-lactamases (ESBL) are becoming an increasingly important cause of resistance to ESC in E. coli, frequently involving the CTX-M-type enzymes (29). In 2008, Boyer-Mariotte et al. reported one case of fatal neonatal meningitis caused by a CTX-M-15-producing E. coli strain (7). Emergence of ESBL-producing Enterobacteriaceae is a major problem, since the choice of drugs for antimicrobial treatment is limited; moreover, such strains have been increasingly implicated in nosocomial outbreaks in neonatal intensive care units (11,23,33,35). While the spread of CTX-M-type ESBL in the family Enterobacteriaceae, especially in E. coli, has been described worldwide (11,13,15,17), the spread of TEM-type ESBL has been less frequently reported (8, 9). We report here a case of neonatal meningitis caused by a TEM-52 ESBL-producing E. coli strain within a serious outbreak among neonates with rectal colonization and the characteristics of the strain. MATERIA...

Clostridium difficile is now recognized as the major agent responsible for nosocomial diarrhea in adults. Among the genotyping methods available, arbitrarily primed PCR (AP-PCR), PCR-ribotyping, and pulsed-field gel electrophoresis (PFGE) have been widely used for investigating outbreaks of C. difficileinfections. However, the comparative typing ability, reproducibility, discriminatory power, and efficiency of these methods have not been fully investigated. We compared the results of three methods—AP-PCR with three different primers (AP3, AP4, and AP5), PCR-ribotyping, and PFGE (with SmaI endonuclease)—to differentiate 99 strains of C. difficile that had been previously serogrouped. Typing abilities were 100% for PCR-ribotyping and AP-PCR with AP3 and 90% for PFGE, due to early DNA degradation in strains from serogroup G. Reproducibilities were 100% for PCR-ribotyping and PFGE but only 88% for AP-PCR with AP3, 67% for AP-PCR with AP4, and 33% for AP-PCR with AP5. Discriminatory power for unrelated strains was >0.95 for all the methods but was lower for PCR-ribotyping among serogroups D and C. PCR-based methods were easier and quicker to perform, but their fingerprints were more difficult to interpret than those of PFGE. We conclude that PCR-ribotyping offers the best combination of advantages as an initial typing tool for C. difficile.