Prognosis of prosthetic valve infective endocarditis due to Streptococcus spp., a retrospective multi-site study to assess the impact of antibiotic treatment duration.

PURPOSE: The duration of antibiotic treatment for prosthetic valve endocarditis caused by Streptococcus spp. is largely based on clinical observations and expert opinion rather than empirical studies. Here we assess the impact of a shorter antibiotic duration. OBJECTIVES: To assess the impact of antibiotic treatment duration for streptococcal prosthetic valve endocarditis on 12-month mortality as well as subsequent morbidity resulting in additional cardiac surgical interventions, and rates of relapse and reinfection. METHODS: This retrospective multisite (N= 3) study examines two decades of data on patients with streptococcal prosthetic valve endocarditis receiving either 4 or 6 weeks of antibiotics. Overall mortality, relapse, and reinfection rates were also assessed for the entire available follow-up period. RESULTS: The sample includes 121 patients (median age 72 years, IQR [53; 81]). The majority (74%, 89/121) received a ß-lactam antibiotic combined with aminoglycoside in 74% (89/121, median bi-therapy 5 days [1; 14]). Twenty-eight patients underwent surgery guided by ESC-guidelines (23%). The 12-month mortality rate was not significantly affected by antibiotic duration (4/40, 10% in the 4-week group vs 3/81, 3.7% in the 6-week group, p=0.34) or aminoglycoside usage (p=0.1). Similarly, there were no significant differences between the 2 treatment groups for secondary surgical procedures (7/40 vs 21/81, p=0.42), relapse or reinfection (1/40 vs 2/81 and 2/40 vs 5/81 respectively). CONCLUSIONS: Our study found no increased adverse outcomes associated with a 4-week antibiotic duration compared to the recommended 6-week regimen. Further randomized trials are needed to ascertain the optimal duration of treatment for streptococcal endocarditis.

Local outbreak of extended-spectrum ß-lactamase SHV2a-producing Pseudomonas aeruginosa reveals the emergence of a new specific sub-lineage of the international ST235 high-risk clone.

BACKGROUND: Pseudomonas aeruginosa is a major bacterial pathogen responsible for hospital-acquired infections. Although its epidemiology is considered as non-clonal, certain international high-risk multidrug-resistant clones have been recognized. AIM: From the first report of an intra-hospital outbreak due to an SHV2a-producing P. aeruginosa strain, to describe the emergence of a new ST235-specific lineage harbouring this rare extended-spectrum ß-lactamase (ESBL). METHODS: Between May and October 2018, four patients hospitalized in the cardiovascular intensive care unit of a French teaching hospital were infected by a multidrug-resistant P. aeruginosa isolate. Serotype and antimicrobial susceptibility were tested; multi-locus sequence type (MLST), core genome MLST, and resistome were determined through whole genome sequencing. A phylogenetic analysis based on single nucleotide polymorphism was performed using available ST235 genomes. FINDINGS: The four strains were susceptible to colistin, ciprofloxacin, ceftazidime-avibactam, and ceftolozane-tazobactam. blaSHV2a was identified in each genome of this ST235-O11 serotype cluster that showed an identical cgMLST profile (0-2 out of 4162 different alleles). The phylogenic analysis of 162 ST235 genomes showed that only four other strains harboured a blaSHV2a, originating from France and USA, clustering together although being different from the outbreak strains. CONCLUSIONS: Among the ST235 P. aeruginosa strains, a sub-lineage sharing a common genetic background and harbouring the blaSHV2a ESBL seems to emerge from different locations, yielding secondary local outbreaks.

Inventory of Extended-Spectrum-ß-Lactamase-Producing Enterobacteriaceae in France as Assessed by a Multicenter Study.

The objective of this study was to perform an inventory of the extended-spectrum-ß-lactamase (ESBL)-producing Enterobacteriaceae isolates responsible for infections in French hospitals and to assess the mechanisms associated with ESBL diffusion. A total of 200 nonredundant ESBL-producing Enterobacteriaceae strains isolated from clinical samples were collected during a multicenter study performed in 18 representative French hospitals. Antibiotic resistance genes were identified by PCR and sequencing experiments. The clonal relatedness between isolates was investigated by the use of the DiversiLab system. ESBL-encoding plasmids were compared by PCR-based replicon typing and plasmid multilocus sequence typing. CTX-M-15, CTX-M-1, CTX-M-14, and SHV-12 were the most prevalent ESBLs (8% to 46.5%). The three CTX-M-type EBSLs were significantly observed in Escherichia coli (37.1%, 24.2%, and 21.8%, respectively), and CTX-M-15 was the predominant ESBL in Klebsiella pneumoniae (81.1%). SHV-12 was associated with ESBL-encoding Enterobacter cloacae strains (37.9%). qnrB, aac(6')-Ib-cr, and aac(3)-II genes were the main plasmid-mediated resistance genes, with prevalences ranging between 19.5% and 45% according to the ESBL results. Molecular typing did not identify wide clonal diffusion. Plasmid analysis suggested the diffusion of low numbers of ESBL-encoding plasmids, especially in K. pneumoniae and E. cloacae However, the ESBL-encoding genes were observed in different plasmid replicons according to the bacterial species. The prevalences of ESBL subtypes differ according to the Enterobacteriaceae species. Plasmid spread is a key determinant of this epidemiology, and the link observed between the ESBL-encoding plasmids and the bacterial host explains the differences observed in the Enterobacteriaceae species.

Switch to oral antibiotics in the treatment of infective endocarditis is not associated with increased risk of mortality in non-severely ill patients.

Although many international guidelines exist for the management of infective endocarditis (IE), recommendations are lacking on the opportunity of switching antibiotics from the intravenous (IV) to oral route during treatment. We present a cohort study of 426 cases of IE over a period of 13 years (2000-2012), including 369 cases of definite IE according to the Duke criteria. Predictors of mortality were identified using the Cox proportional hazard analysis. The median (range) age at diagnosis was 64.5 (7-98) years. One hundred six patients (25%) had healthcare-associated IE. Oral streptococci (n = 99, 23%) and Staphylococcus aureus (n = 81, 19%) were the predominant microorganisms. Ninety-two patients (22%) died during follow-up. After an initial phase of IV antibiotherapy, 214 patients (50%) were switched to oral route a median (range) of 21 (0-70) days after diagnosis of IE. Patients in the oral group had fewer comorbidities, and criteria of severity at inclusion and were less frequently infected by S. aureus. Oral antibiotics were amoxicillin alone in 109 cases or a combination therapy of clindamycin, fluoroquinolone, rifampicin and/or amoxicillin in 46 cases, according to the susceptibility of the microorganisms. In the multivariate analysis, a switch to oral route was not associated with an increased risk of mortality. During follow-up, only two relapses and four reinfections were observed in the oral group (compared to nine and eight in the IV group, respectively). In this study, switching to oral administration was not associated with an increased risk of relapse or reinfection. These promising results need to be confirmed by prospective studies.

[Bloodstream infection due to Campylobacter fetus subspecies fetus and skin involvement: A case series of three patients]. / Bactériémie à Campylobacter fetus subspecies fetus et manifestations cutanées : à propos de trois cas.

INTRODUCTION: Among the species of Campylobacter, C. fetus subspecies fetus is characterized by extra-intestinal manifestations, including bloodstream and cardiovascular infections, occurring preferentially in the context of immunosuppression. The cutaneous lesions are rarely described but may be underestimated. CASE REPORTS: We report on 3 cases of cellulitis with bloodstream infection due to Campylobacter fetus subspecies fetus, without cardiovascular infection in a 72- and 85-year-old women, respectively, and a 79-year-old man. Outcome was successful in all 3 cases after prolonged amoxicillin-clavulanic acid treatment, without relapse. CONCLUSION: C. fetus subspecies fetus is rarely associated with skin and soft tissue infections. Cardiovascular complications may be searched in such context.

Chronic endocarditis due to Legionella anisa: a first case difficult to diagnose.

Endocarditis due to Legionella spp. is uncommon but presumably underestimated given the prevalence of Legionellae in the environment. We report a first and unusual case of chronic native valve endocarditis due to L. anisa and advocate that the diagnosis of endocarditis be made collaboratively between the cardiologist, surgeon, microbiologist and pathologist.

Early detection with the ß-LACTA™ test of extended-spectrum ß-lactamase-producing Enterobacteriaceae in blood cultures.

Effective antibiotic therapy is crucial for the outcome of septic patients and requires early diagnosis of ß-lactam resistance in cases of Gram-negative bacteremia. Here, we report high sensitivity of the ß-LACTA™ test in rapid detection of extended-spectrum ß-lactamase-producing Enterobacteriaceae in blood cultures positive for Gram-negative bacilli.

Assessment of five screening strategies for optimal detection of carriers of third-generation cephalosporin-resistant Enterobacteriaceae in intensive care units using daily sampling.

There is no consensus on optimal screening procedures for multidrug-resistant Enterobacteriaceae (MDRE) in intensive care units (ICUs). Therefore, we assessed five strategies for the detection of extended-spectrum beta-lactamase (ESBL) and high-level expressed AmpC cephalosporinase (HL-CASE) producers. During a 3-month period, a rectal screening swab sample was collected daily from every ICU patient, from the first 24 h to the last day of ICU stay. Samples were plated on MDRE-selective media. Bacteria were identified using MALDI-TOF mass spectrometry and antibiograms were performed using disk diffusion. MDREs were isolated from 682/2348 (29.0%) screening samples collected from 93/269 (34.6%) patients. Incidences of patients with ESBL and HL-CASE producers were 17.8 and 19.3 per 100 admissions, respectively. In 48/93 patients, MDRE carriage was intermittent. Compared with systematic screening at admission, systematic screening at discharge did not significantly increase the rate of MDRE detection among the 93 patients (62% vs. 70%). In contrast, screening at admission and discharge, screening at admission and weekly thereafter, and screening at admission and weekly thereafter and at discharge significantly increased MDRE detection (77%, p 0.02; 76%, p 0.01; 86%, p<0.001, respectively). The difference in MDRE detection between these strategies relies essentially on the levels of detection of patients with HL-CASE producers. The most reasonable strategy would be to collect two samples, one at admission and one at discharge, which would detect 87.5% of the ESBL strains, 67.3% of the HL-CASE strains and 77.4% of all MDRE strains. This study should facilitate decision-making concerning the most suitable screening policy for MDRE detection in a given ICU setting.

Comparison of five media for detection of extended-spectrum Beta-lactamase by use of the wasp instrument for automated specimen processing.

Overall, 2,337 rectal screening samples (RSSs) were seeded by using the Wasp instrument for automated microbiological processing with five media for detection of extended-spectrum ß-lactamase (ESBL): CHROMagar, ChromID, Brilliance, BD Drigalski, and HEGP media. Of 354 RSSs harboring ESBL-producing isolates, 89.3% were found to be positive on all media. Sensitivity and specificity ranged from 95.5 to 98.3% and from 57.9 to 72.3%, respectively. No medium was perfectly ESBL selective, and non-ESBL-producing strains were mainly Enterobacteriaceae overproducing AmpC ß-lactamase and nonfermenting Gram-negative bacilli, mostly Pseudomonas aeruginosa.

Diagnosis, management and outcome of Candida endocarditis.

Limited data exist on Candida endocarditis (CE) outcome in the era of new antifungals. As early diagnosis of CE remains difficult, non-culture-based tools need to be evaluated. Through the French prospective MYCENDO study (2005-2007), the overall characteristics and risk factors for death from CE were analysed. The contribution of antigen detection (mannan/anti-mannan antibodies and (1,3)-ß-d-glucans) and molecular tools was evaluated. Among 30 CE cases, 19 were caused by non-albicans species. Sixteen patients (53%) had a predisposing cardiac disease, which was a valvular prosthesis in ten (33%). Nine patients (30%) were intravenous drug users; none of them had right-sided CE. Among the 21 patients who were not intravenous drug users, 18 (86%) had healthcare-associated CE. Initial therapy consisted of a combination of antifungals in 12 of 30 patients (40%). Thirteen patients (43%) underwent valve replacement. The median follow-up was 1 year after discharge from hospital (range, 5 months to 4 years) and hospital mortality was 37%. On univariate analysis, patients aged ≥60 years had a higher mortality risk (OR 11, 95% CI 1.2-103.9; p 0.024), whereas intravenous drug use was associated with a lower risk of death (OR 0.12, 95% CI 0.02-0.7; p 0.03). Among 18 patients screened for both serum mannan/anti-mannan antibodies and (1,3)-ß-d-glucans, all had a positive result with at least one of either test at CE diagnosis. Real-time PCR was performed on blood (SeptiFast) in 12 of 18, and this confirmed the blood culture results. In conclusion, CE prognosis remains poor, with a better outcome among younger patients and intravenous drug users. Detection of serum antigens and molecular tools may contribute to earlier CE diagnosis.

Corynebacterium jeikeium pacemaker infection associated with antineutrophil cytoplasmic antibodies: a single positive blood culture could be sufficient for diagnosis.

Corynebacterium jeikeium, a member of the non-diphtheria corynebacteria, has been rarely reported as being responsible for cardiovascular-device infection. Here, we report what is believed to be the first case of C. jeikeium pacemaker infection associated with the presence of proteinase-3 antineutrophil cytoplasmic antibodies. The diagnosis was established based on the positivity of a single positive blood culture and led to pacemaker extraction. This observation highlights the difficulty in the diagnosis of cardiac-device infection in the presence of a single positive blood culture with a fastidious microorganism that could be considered as a contaminant. It also underscores the need for device extraction to ensure healing.

Bactericidal efficacy of a 1.5min surgical hand-rubbing protocol under in-use conditions.

In healthy volunteers, surgical hand rubbing with Sterillium for 1.5min has been shown to be as effective as a 3min procedure. The aim of this study was to assess whether this result was reproducible under in-use conditions. During nine weeks in the ambulatory surgery theatre of a 750-bed tertiary care university hospital, the two surgical hand-rubbing procedures were compared with each other, and with a hand-scrubbing procedure using a povidone-iodine (4%) scrub prior to and after 25 different surgical operations for each. Imprints of the surgeon's dominant hand were taken on culture plates before and within 1min following the end of the hand-rubbing/scrubbing procedures (immediate effect) and at the end of surgery (sustained effect). Plates were incubated aerobically at 37 degrees C for 48h. Colonies were counted at 24h and 48h. Results were expressed as the number of colony-forming units per hand. No significant difference in baseline hand bacterial load was found before the hand-rubbing/scrubbing procedures among the three groups (P=0.19). With respect to immediate and sustained antimicrobial effects, a significantly greater reduction in microbial loads on the hands was achieved with the 3min hand-rubbing protocol as opposed to hand-scrubbing protocol (P=0.04 and P=0.02, respectively), but there was no difference between the reductions obtained with 1.5 and 3min rubbing protocols (P=0.41 and P=0.36, respectively). Surgical hand rubbing with Sterillium using a 1.5min protocol should be considered as an attractive alternative method for surgical hand disinfection.

Evaluation of a new disinfection procedure for ultrasound probes using ultraviolet light.

Following 183 ultrasound examinations, a randomized trial was conducted to compare three procedures for disinfection of probes under routine conditions: dry wiping with a soft, dry, non-sterile paper towel, antiseptic wiping with a towel impregnated with disinfectant spray and dry wiping followed by a 10 min ultraviolet C (UVC) cycle in a disinfection chamber. After ultrasonography, swabs were taken from transducer heads before and after cleaning and streaked onto plates that were then cultured. The number of colonies per plate was counted and organisms identified. The median microbial reduction was 100% for UVC, 98.4% for antiseptic wiping and 87.5% for dry wiping (P<0.001). The percentage of negative specimens was 88% for UVC, 16% for antiseptic wiping and 4% for dry wiping (P<0.0001). Microbial flora was isolated from 12 probes (6.6%) before cleaning, whereas specimens obtained after cleaning contained no pathogens except in one case after antiseptic wiping. UVC disinfection of ultrasound probe may provide a useful method for reducing the bacterial load under routine conditions.

Microbiological evaluation of two hand hygiene procedures achieved by healthcare workers during routine patient care: a randomized study.

The aim of this study was to evaluate the comparative microbiological efficacy of hand rubbing and handwashing in healthcare workers from different wards, with particular emphasis on transient flora, and to assess predisposing factors for hand contamination after patient care in everyday practice. Over a six-month period, 50 healthcare workers were randomly assigned, using a crossover design, to perform handwashing with unmedicated soap and hand rubbing with an alcoholic solution following a healthcare procedure. Imprints of palms and fingertips were taken separately before and after each hand hygiene procedure. The number of colonies per plate was counted and transient pathogens were identified. Risk factors for hand contamination were determined. Hand rubbing produced a significantly greater reduction in microbiological load than handwashing (P<0.0001 for palms and P=0.0003 for fingertips). In multivariate analysis, working in a medical ward rather than in an intensive care unit was significantly associated with increased hand contamination (P=0.03 for palms and P=0.02 for fingertips). Transient pathogens were found on 15% of healthcare workers' hands before hand hygiene. The only factor associated with hand contamination by transient pathogens was the absence of gloving during the healthcare procedure (odds ratio 4.8; 95% confidence interval 1.2-19; P=0.03). After hand rubbing, no transient pathogens were recovered, while these were found in two cases after handwashing. Hand rubbing is more efficacious than handwashing for the decontamination of healthcare workers' hands following contact with patients and patients' environments. Gloving may reduce microbiological hand contamination by transient pathogens.

Molecular diagnosis of a vascular prosthesis infection, due to Propionibacterium acnes, by amplification and sequencing of 16S rDNA.

We describe a case of indolent vascular prosthesis infection due to Propionibacterium acnes. The microorganism was identified only by amplification and sequencing of 16S rDNA, while standard cultures remained negative. This observation underscores the usefulness of molecular techniques for the diagnosis of infection caused by fastidious microorganisms.

Multiple mobile promoter regions for the rare carbapenem resistance gene of Bacteroides fragilis.

Two novel insertion sequences (IS), IS1187 and IS1188, are described upstream from the carbapenem resistance gene cfiA in strains of Bacteroides fragilis. Mapping, with the RACE procedure, of transcription start sites of cfiA in these and two other previously reported IS showed that transcription of this rarely encountered gene is initiated close to a variety of B. fragilis consensus promoter sequences, as recently defined (D. P. Bayley, E. R. Rocha, and C. J. Smith, FEMS Microbiol. Lett. 193:149-154, 2000). In the cases of IS1186 and IS1188, these sequences overlap with putative Esigma(70) promoter sequences, while in IS942 and IS1187 such sequences can be observed either upstream or downstream of the B. fragilis promoters.

Impact of antimicrobial therapy on nasopharyngeal carriage of Streptococcus pneumoniae, Haemophilus influenzae, and Branhamella catarrhalis in children with respiratory tract infections.

We conducted a multicenter prospective study to document changes in nasopharyngeal carriage of Streptococcus pneumoniae, Haemophilus influenzae, and Branhamella catarrhalis during antibiotic therapy. A cohort of 629 children with respiratory tract infections underwent nasopharyngeal sampling before and after antibiotic treatment. Susceptibility testing, serotyping, arbitrarily primed polymerase chain reaction, and pulsed-field gel electrophoresis were used to compare pretreatment and posttreatment strains of S. pneumoniae. A significant decrease in carriage of all 3 species (especially S. pneumoniae and B. catarrhalis) was recorded. The increase in the proportion of penicillin-resistant pneumococci (PRP; 66% vs. 44%) was due to the decreased carriage of penicillin-susceptible pneumococci (71 of 629 vs. 176 of 629). The risk of PRP carriage in a given child did not increase. None of the children was found to harbor genetically related strains with increased minimum inhibitory concentrations. Given the multiple resistance of PRP, beta-lactam antibiotic therapy also increased the incidence of macrolide-resistant strains, whereas macrolides selected both macrolide- and penicillin-resistant strains.

Outbreak of methicillin-resistant Staphylococcus aureus with reduced susceptibility to glycopeptides in a Parisian hospital.

Epidemiological relationships were investigated between 40 methicillin-resistant Staphylococcus aureus (MRSA) strains with decreased glycopeptide susceptibility isolated from November 1998 to March 1999 from 39 patients (17 infected and 22 colonized patients) in nine wards of the Broussais Hospital, Paris, France. Reduced glycopeptide susceptibility was readily detected on brain heart infusion (BHI) agar containing 6 microg of teicoplanin per ml and on gradient plates, but not by the standard disk diffusion method. The MICs of vancomycin and teicoplanin, determined on BHI agar, were 4 and 8 to 32 microg/ml, respectively (standard antibiotic dilution), and 4 to 8 and 8 to 32 microg/ml, respectively (E-test). All strains were resistant to macrolides, aminoglycosides, tetracycline, rifampin, sulfonamides, and pefloxacin, showed reduced susceptibility to fusidic acid and fosfomycin, and were susceptible to trimethoprim and chloramphenicol. Pulsed-field gel electrophoresis and lysotyping revealed that a multidrug-resistant MRSA clone with decreased susceptibility to glycopeptides has been discretely endemic since at least 1996 in our institution, where it was responsible for an outbreak in November and December 1998.