Outbreaks caused by Enterobacteriaceae isolates producing extended-spectrum β-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.
Rapid diagnostic tests detecting microbial resistance are needed for limiting the duration of inappropriateness of empirical antimicrobial therapy (EAT) in intensive care unit patients, besides ...reducing the use of broad-spectrum antibiotics. We hypothesized that the betaLACTA® test (BLT) could lead to early increase in the adequacy of antimicrobial therapy.
This was a case-control study. Sixty-one patients with BLT-guided adaptation of EAT were prospectively included, and then matched with 61 "controls" having similar infection characteristics (community or hospital-acquired, and source of infection), in whom EAT was conventionally adapted to antibiogram results. Endpoints were to compare the proportion of appropriate (primary endpoint) and optimal (secondary endpoint) antimicrobial therapies with each of the two strategies, once microbiological sample culture results were available.
Characteristics of patients, infections and EAT at inclusion were similar between groups. Nine early escalations of EAT occurred in the BLT-guided adaptation group, reaching 98% appropriateness vs. 77% in the conventional adaptation group (p < 0.01). The BLT reduced the time until escalation of an inappropriate EAT from 50.5 (48-73) to 27 (24-28) hours (p < 0.01). Seventeen early de-escalations occurred in the BLT-guided adaptation group, compared to one in the conventional adaptation group, reducing patients' exposure to broad-spectrum beta-lactam such as carbapenems. In multivariate analysis, use of the BLT was strongly associated with early appropriate (OR = 18 (3.4-333.8), p = 0.006) and optimal (OR = 35.5 (9.6-231.9), p < 0.001) antimicrobial therapies. Safety parameters were similar between groups.
Our study suggests that a BLT-guided adaptation strategy may allow early beta-lactam adaptation from the first 24 hours following the beginning of sepsis management.
Global dissemination of Escherichia coli producing CTX-M extended-spectrum β-lactamases (ESBL) is a public health concern. The aim of the study was to determine factors associated with CTX-M- ...producing E. coli infections among patients hospitalised in the Assistance Publique-Hôpitaux de Paris, the largest hospital system in France (23 000 beds), through a prospective case-control-control study.
From November 2008 to June 2009, 152 inpatients with a clinical sample positive for CTX-M-producing E. coli (cases), 152 inpatients with a clinical sample positive for non ESBL-producing E. coli on the day or within the three days following case detection (controls C1), and 152 inpatients with culture-negative clinical samples since the beginning of hospitalisation and until three days after case detection (controls C2) were included in ten hospitals of the Paris area. Factors studied were related to patient's origin, lifestyle and medical history as well as care during hospitalisation. Those independently associated with CTX-M-producing E. coli were determined. Three independent factors were common to the two case-control comparisons: birth outside of Europe (cases vs C1: OR(1) = 2.4; 95%CI = 1.3-4.5 and cases vs C2: OR(2) = 3.1; 95%CI = 1.4-7.0), chronic infections (OR(1) = 2.9; 95%CI = 1.3-6.9 and OR(2) = 8.7; 95%CI = 2.0-39.7), and antibiotic treatment between hospital admission and inclusion (OR(1) = 2.0; 95%CI = 1.0-3.8 and OR(2) = 3.3; 95%CI = 1.5-7.2). Cases were also more likely to be (i) functionally dependent before hospitalisation than C2 (OR(2) = 7.0; 95%CI = 2.1-23.5) and (ii) living in collective housing before hospitalisation than C2 (OR(2) = 15.2; 95%CI = 1.8-130.7) when CTX-M-producing E. coli was present at admission.
For the first time, patient's origin and lifestyle were demonstrated to be independently associated with isolation of CTX-M-producing E. coli, in addition to health care-related factors.
Sixty-two isolates of Enterobacteriaceae (35 Escherichia coli and 27 Klebsiella pneumoniae isolates) producing CTX-M-type β-lactamases were collected between March 2000 and June 2003 in different ...wards of Charles Nicolle Hospital in Tunis (Tunisia). Sequencing identified the blaCTX₋M₋₁₅ determinant in 55 isolates and blaCTX₋M₋₁₆ in 7 isolates. The CTX-M-15-producing strains were isolated in several wards and consisted mainly of two successive clonal groups of E. coli and a major clonal group of K. pneumoniae. The second clonal group of E. coli belonged to phylogenetic group B2 and harbored more virulence factors than the first clonal group. Among the 22 transconjugants or electroporants obtained with selected E. coli and K. pneumoniae CTX-M-15-producing strains, a predominant plasmid restriction pattern was obtained with 17 isolates. The four CTX-M-16-producing strains of E. coli yielded the same pulsed-field gel electrophoresis (PFGE) pattern, while the three CTX-M-16-producing strains of K. pneumoniae yielded two different PFGE patterns. All of the CTX-M-16-producing isolates were recovered in the pediatric ward and had the same plasmid restriction pattern.
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