Risk Factors and Outcomes for Intestinal Carriage of AmpC-Hyperproducing Enterobacteriaceae in Intensive Care Unit Patients.

In a cohort of 1,209 intensive care unit (ICU) patients, the prevalence of intestinal colonization with high-level expressed AmpC cephalosporinase-producing Enterobacteriaceae (HLAC-PE) rose steadily from 2% at admission to 30% in patients with lengths of stay (LOS) exceeding 4 weeks. In multivariate analysis, LOS was the main predictor of carriage acquisition after adjustment on antimicrobial exposure. HLAC-PE infection occurred in 15% of carriers. Carriage and infection were associated with a marked increase in carbapenem consumption.

Crucial role of TNF receptors 1 and 2 in the control of polymicrobial sepsis.

Sepsis is still a major cause of mortality in the intensive critical care unit and results from an overwhelming immune response to the infection. TNF signaling pathway plays a central role in the activation of innate immunity in response to pathogens. Using a model of polymicrobial sepsis by i.p. injection of cecal microflora, we demonstrate a critical role of TNFR1 and R2 activation in the deregulated immune responses and death associated with sepsis. A large and persistent production of TNF was found in wild-type (B6) mice. TNFR1/R2-deficient mice, compared with B6 mice, survive lethal polymicrobial infection with enhanced neutrophil recruitment and bacterial clearance in the peritoneal cavity. Absence of TNFR signaling leads to a decreased local and systemic inflammatory response with diminished organ injury. Furthermore, using TNFR1/R2-deficient mice, TNF was found to be responsible for a decrease in CXCR2 expression, explaining reduced neutrophil extravasation and migration to the infectious site, and in neutrophil apoptosis. In line with the clinical experience, administration of Enbrel, a TNF-neutralizing protein, induced however only a partial protection in B6 mice, with no improvement of clinical settings, suggesting that future TNF immunomodulatory strategies should target TNFR1 and R2. In conclusion, the present data suggest that the endogenous TNFR1/R2 signaling pathway in polymicrobial sepsis reduces neutrophil recruitment contributing to mortality and as opposed to pan-TNF blockade is an important therapeutic target for the treatment of polymicrobial sepsis.

Septic arthritis caused by Erysipelothrix rhusiopathiae in a prosthetic knee joint.

We describe the third case of prosthetic infection due to Erysipelothrix rhusiopathiae. The patient, a 68-year-old woman, had had total knee arthroplasty 12 months before diagnosis. She had been in contact with swine at home. We review the seven previous reports of septic arthritis due to E. rhusiopathiae.

Prepartum vaginal/anorectal Group B Streptococcus screening: improvement of the enrichment step by the broth additive RambaQUICK StrepB.

We used RambaQUICK StrepB in enrichment broth with samples taken from 31 pregnant women and compared its performance to that of standard enrichment media. RambaQUICK StrepB shortened the required incubation time and raised the sensitivity of streptococcal screening by 1.6 fold.

Evaluation of CHROMagar™ StrepB agar, an aerobic chromogenic medium for prepartum vaginal/rectal Group B Streptococcus screening.

An aerobic chromogenic medium, CHROMagar™ StrepB agar, designed for isolation of group B Streptococci, was evaluated on 285 prepartum vaginal/rectal swabs from pregnant women. After overnight enrichment in Todd-Hewitt broth containing 15µg/ml nalidixic acid and 10µg/ml colistin, sensitivities were respectively 79% on day 1 and 92% on day 2, and significantly higher than those achieved by blood agar (40% and 58%) and colimycin-nalidixic-acid agar (82% on day 2).

Evaluation of CHROMagar StrepB: a new chromogenic agar medium for aerobic detection of Group B Streptococci in perinatal samples.

A selective and chromogenic medium, the CHROMagar StrepB agar (CHROM-B) designed for aerobic isolation of Group B Streptococci (GBS) in pregnancy-related specimens, was evaluated in a two-Phase study. CHROM-B was evaluated against CPS3 during the first Phase and against Granada afterwards. It was compared to blood agar plates (COH) and to colimycin nalidixic agar plates (CNA) over both Phases. The study which included 1356 samples, yielded 124 GBS. CHROM-B was significantly more sensitive than COH (76.6% vs 53.2% on d1 and 92.7% vs 64.5% on d2; p<0.001 for both). CHROM-B yielded positive results sooner than CNA. CPS3 under-performed, partly because of microbiota overgrowth and partly because it did not produce a single and unique colour from the GBS colonies. CHROM-B produced its unique GBS-expected colour sooner than Granada yielding a significantly sooner result for 10% (6/60; p<0.025). Every 124 GBS could grow typical colonies on CHROM-B and False Negatives were only due to paucimicrobial samples. Granada failed to produce the expected colour from one non-haemolytic GBS. We conclude that CHROMagar StrepB performed significantly better, irrespective of the haemolytic properties of GBS strains, and significantly sooner than COH, CNA, CPS3 and Granada.