A case of bacteriemic mediastinitis due to Prevotella buccae after cardiac surgery.

Mediastinitis is a well-known complication of open-heart surgery. Strictly anaerobic bacteria are rarely found in this condition, unlike in descending mediastinitis. We report the case of a mediastinitis due to Prevotella buccae after surgical replacement of the aortic valve and triple coronary artery bypass in an immunocompetent 76 year-old man. The bacteria were found in pure culture on blood samples and surgical samples. This case emphasizes the need to perform anaerobic cultures in case of sternal wound infection after open-heart surgery.

Spontaneous decolonization during hospitalization in intensive care unit patients colonized by extended-spectrum beta-lactamase-producing Enterobacterales.

This study aimed to analyse the frequency of occurrence of spontaneous decolonization in intensive care unit patients colonized by extended-spectrum beta-lactamase-producing Enterobacterales (ESBL-E) in order to assess the added value of continuing weekly ESBL-E rectal carriage screening in these patients. In total, 49,468 weekly rectal screening samples taken from 20,846 patients over 12 years were included. Among the 4280 ESBL-E carriers, only 109 patients (2.5%) could be considered decolonized at the end of their hospitalization with at least three consecutive negative samples. Overall, 7957 samples (16.1%) were requested for patients already identified as ESBL-E carriers. Avoiding unnecessary weekly screening following positive ESBL-E colonization results could decrease nursing and laboratory work loads.

In vitro activity of temocillin against extended-spectrum beta-lactamase-producing Escherichia coli and Klebsiella pneumoniae strains isolated from urinary tract infections in France.

OBJECTIVES: Temocillin was introduced in 2015 in the French guidelines for the treatment of extended-spectrum beta-lactamase (ESBL)-producing Enterobacteriaceae urinary tract infections. Little susceptibility data is available. We investigated the in vitro activity of temocillin against ESBL-producing Enterobacteriaceae isolated from samples of cytobacteriological examinations of urine. MATERIAL AND METHODS: Susceptibility testing was performed on 157 ESBL-producing E. coli and 95 ESBL-producing K. pneumoniae strains using the disk diffusion method. MICs of resistant strains were measured with the Etest method. RESULTS: Using current breakpoints, 71.3% of E. coli strains and 77.9% of K. pneumoniae strains were classified as susceptible. However, diameter and MIC breakpoints vary by country, and we reported discordance of clinical categorization between diameters and MIC determination for some strains. The measure of diameters was also sometimes difficult because of contaminating colonies within the inhibition zone. CONCLUSION: We highlighted difficulties related to the determination of temocillin susceptibility, such as culture of resistant colonies in the inhibition zone and discordance of clinical categorizations obtained with the disk diffusion method or the Etest method. Overall, 42% of tested Enterobacteriaceae had a diameter or MIC close to the current breakpoints; thus, it is necessary to determine the MIC for these strains before considering the clinical use of this molecule.

Trimethoprim susceptibility in E. coli community-acquired urinary tract infections in France.

OBJECTIVES: Trimethoprim has been recently included in the French guidelines for the treatment of urinary tract infections, but no epidemiological data supports its use. We aimed to determine the trimethoprim susceptibility of Escherichia coli isolates responsible for community-acquired urinary tract infections in women of childbearing age. MATERIALS AND METHODS: We conducted a national prospective survey. A total of 350 strains of E. coli isolated from urines in 35 laboratories were included. Antibiotic susceptibility testing was performed in each laboratory. RESULTS: We reported a susceptibility rate of 78%, and a similar clinical categorization between trimethoprim and cotrimoxazole for 97.4% of isolates. We pointed out an association between resistance to trimethoprim and other antibiotic classes. CONCLUSION: The results support trimethoprim as a second-line therapy based on antibiotic susceptibility testing results. We confirm that trimethoprim and cotrimoxazole susceptibility rates are very close.

A promising new test to detect Streptococcus pneumoniae urinary antigen.

BACKGROUND: Streptococcus pneumoniae is the main etiology of community-acquired pneumonia (CAP). A quick detection of urinary antigen helps in obtaining a documented result in case of Streptococcus pneumoniae CAP. METHODS: We compared the BinaxNOW®S. pneumoniae test with the new urinary antigen Sofia®S. pneumoniae FIA. We examined 133 urine samples. RESULTS: Of the 133 included and tested non-concentrated urine samples, BinaxNOW® and Sofia® tests yielded 122 and 113 negative results and 11 and 20 positive results, respectively. The overall agreement between the tests was good. CONCLUSION: This new test enabled the diagnosis of seven additional cases (7/133=5.2%). The improved detection with Sofia® may be due to the immunofluorescence method used by this new test as compared with the colorimetric method used by BinaxNOW®. Sofia® also offers the advantage of being connected to the laboratory information system (LIS) allowing an automated traceability.

A fatal endocarditis case due to an emerging bacterium: Moraxella nonliquefaciens.

Moraxella nonliquefaciens is a Gram-negative coccobacillus considered as a commensal organism from the upper respiratory tract, with low pathogenic potential. The phenotypical conventional identification is difficult and the matrix-assisted laser desorption/ionization time-of-flight technology has increased the resolution of identification of this bacterium. We report a fatal case of endocarditis due to M. nonliquefaciens whose identification was confirmed by 16S rRNA, and we review the literature on this pathogen in endocarditis.

In vitro susceptibility to mecillinam of Escherichia coli strains isolated from the urine of pregnant women.

OBJECTIVES: Pivmecillinam is a safe beta-lactam for use in pregnancy. It has been widely used for the treatment of lower urinary tract infections (UTIs) in the Nordic countries where its efficacy, minor impact on the microbiota, and low level of resistance among the Escherichia coli strains have been proven. However, susceptibility data related to E. coli involved in asymptomatic bacteriuria and lower UTIs in pregnant women is lacking. We aimed to support the 2015 recommendations issued by the French Infectious Diseases Society (SPILF) on gestational UTI, with a particular focus on pivmecillinam. MATERIAL AND METHODS: Antimicrobial susceptibility testing was performed by 12 hospitals with a maternity department on 235 E. coli strains isolated from the urine of pregnant women. Susceptibility to mecillinam was tested by disk diffusion method using the 2015 recommendations of the antibiogram committee of the French microbiology society (CA-SFM). RESULTS: Global susceptibility to mecillinam was 86.4%. Susceptibility to mecillinam was 96.5% for strains susceptible to amoxicillin-clavulanic acid and 38.7% for resistant strains. All six extended-spectrum beta-lactamase-producing E. coli strains were susceptible to mecillinam. CONCLUSION: Given the efficacy and safety of pivmecillinam during pregnancy, it may be used for the documented treatment of asymptomatic bacteriuria and acute cystitis in pregnant women. It also represents an alternative for the treatment of multidrug-resistant bacterial infections.