Seasonal variations in blood culture numbers and time to positivity and potential impact of reducing incubation periods.

Patients with viral respiratory infections often present symptoms compatible with bloodstream infections. Consequently, the winter period commonly associated with epidemic respiratory illnesses shows an increase in the number of blood cultures (BC) and to occasional saturation of automated BC systems. Here, we explored the seasonal variations in BC samples and the potential impact of shortening the incubation time of BC when automated BC systems are close to saturation. A retrospective study was conducted during a 3-year period in 4 hospitals located in the Paris region, France. All aerobic and anaerobic bottles were included, except pediatric bottles and those sampled for suspicion of endocarditis. The number of BC bottles collected during the winter period was compared to the annual baseline. All bottles positive after a 4-day incubation were analyzed regarding clinical and microbiological findings. The number of BC bottles was significantly higher during the winter periods, compared to the annual baseline (up to 14%). A total of 292,349 BC bottles were analyzed with 23,363 (8.0%) positive, including 236 (1%) after a 4-day incubation. Of these 236 bottles, 76 (64.8%) were positive with a contaminant, 78 (33.1%) with a clinically significant microorganism identified for the same patient in the previous 4 days, and only 5 (2.1%) with a clinically significant microorganism not previously identified. Winter periods were associated with a significant increase in BC samples. Shortening the incubation time of BC bottles from 5 to 4 days seems a relevant option when automated BC systems are close to saturation.

Impact of a multiplex PCR assay (FilmArray®) on the management of patients with suspected central nervous system infections.

Microbiological diagnosis of central nervous system (CNS) infections is challenging due to limited access to CNS samples, overlap between meningitis and encephalitis, and the multiplicity of pathogens potentially involved. We aimed to estimate the impact of a commercial multiplex PCR assay (FilmArray® meningitis/encephalitis) on the management of patients with suspicion of meningitis or encephalitis, in terms of time to diagnosis, antimicrobial agents use, duration of hospitalization, and costs. This prospective observational study was conducted at Saint Joseph Hospital (Paris, France) from December 2016 to December 2017. All CSF samples sent to the microbiology laboratory for suspicion of meningitis and/or encephalitis, with CSF cells count > 5 cells/µL, were tested by meningitis/encephalitis multiplex PCR assay. One hundred thirty patients were included. The multiplex PCR assay was positive in 33 patients (25%). Main pathogens found were Enterovirus (n = 12), Varicella-Zoster virus (n = 7), Herpes simplex virus-2 (n = 6), and Listeria monocytogenes (n = 3) as main pathogens. The multiplex PCR assay reduced time to microbiological diagnosis by 3.3 ± 1.6 days and allowed an earlier discontinuation of empirical anti-infective drugs in 42 patients (32%) and an earlier hospital discharge in 23 patients (18%), with an estimated saving of 82 hospital days overall, and a management cost reduction of 26,242 € (201 €/patient). The systematic use of the FilmArray® meningitis/encephalitis multiplex PCR assay may allow earlier diagnosis, earlier discontinuation of empirical treatment, reduced duration of stay, and costs reduction.

Clinical impact of rapid susceptibility testing on MHR-SIR directly from blood cultures.

BACKGROUND: In a previous study, we demonstrated that rapid antibiotic susceptibility tests (ASTs) can be performed directly on blood culture samples tested on Mueller-Hinton Rapid agar (MHR-SIR) with a time delay of 6-8 h. OBJECTIVES: Using this rapid disc diffusion method, we analysed the clinical impact associated with rapid reporting of results in our hospital setting. METHODS: All patients with bloodstream infections (BSIs) related to Enterobacteriaceae or Staphylococcus aureus were prospectively included in the study. The rapid ASTs were performed by incubation of positive blood cultures on MHR-SIR for 6-8 h by direct inoculation according to BSAC recommendations. RESULTS: One hundred and sixty-seven patients with BSIs were included as MHR-guided adaptation therapy cases. Eighty percent had Enterobacteriaceae-related BSIs, of which 12 (9%) were ESBL producers and 20% were S. aureus-related BSIs. A urinary or intra-abdominal infection was observed in 44.3% and 19.8%, respectively, of Enterobacteriaceae-related infections. The most frequent sources of infections for S. aureus BSIs were cutaneous and endovascular, in 43% and 23% of cases, respectively. Forty-four percent of the patients benefited from therapeutic modification according to the results of the MHR-SIR AST. Thus, empirical antibiotic therapy was modified by using antibiotic therapy that had too wide a spectrum or was unsuitable in 26% and 18% of cases, respectively. Compared with the 24 h required for the reference method, the median length of time to provision of susceptibility test results by MHR-SIR was 7 h. CONCLUSIONS: This study showed a significant time saving (17 h) on the appropriateness of antibiotic prescription and demonstrated a significant impact regarding the choice and reduction of the spectrum of antibiotic therapy.

Microbiological Profile of Instrumented Spinal Infections: 10-Year Study at a French Spine Center.

OBJECTIVE: The objective was to compare the microbiological characteristics and treatment of early and late surgical site infections (SSIs) in instrumented spinal surgery. METHODS: Those patients admitted for SSIs in a single center between January 2010 and December 2022 were included. The subjects were divided into early (eSSIs) and late (lSSIs) SSIs, and demographic, microbiological, treatment, and follow-up data were collected. RESULTS: Instrumented spinal surgery was performed in 2136 patients. Ninety-six cases of infections were identified (prevalence = 4.5%), with 47.9% eSSIs and 52.1% lSSIs. In 58.7% of the cases, the eSSIs were monomicrobial: Staphylococcus aureus (37%) and Enterobacterales (33.3%) were the main bacteria involved. In 66% of the cases, the lSSIs, were monomicrobial: Cutibacterium acnes (30.3%) and staphylococci were predominant. Enterobacterales were isolated in more than 70% of the polymicrobial samples in both the eSSIs and lSSIs. The treatment of the eSSIs mostly consisted of lavage-debridement surgery associated with antibiotic treatment, while the treatment of the lSSIs combined hardware removal or replacement and long-duration antibiotic treatment. A negative outcome was observed in 17.1% of the eSSIs and 5.7% of the lSSIs. Enterobacterales were associated with negative outcomes of eSSIs. CONCLUSIONS: Enterobacterales were found in most of the polymicrobial infections regardless of the time of infection onset. Further large studies should be conducted to precisely determine the management and prevention regarding the increasing Gram-negative bacteria SSIs.

Chlamydia psittaci endocarditis: A case report and literature review.

OBJECTIVES: Blood-culture-negative infective endocarditis (BCNE) is found in 2 to 48% of cases of infective endocarditis (IE) (Houpikian and Raoult, 2005) [1].IE and vertebral osteomyelitis due to Chlamydia sp. are difficult to diagnose. PATIENTS AND METHODS: A case report of Chlamydia psittaci IE is provided, associated with a literature review. RESULTS: We report the first case of Chlamydia psittaci IE, revealed by a spondylodiscitis. Questioning of the patient, imaging, serologies and PCR techniques on valves confirmed the diagnosis. CONCLUSION: C. psittaci IE is rare but probably underdiagnosed. In case of negative blood cultures, questioning patients with IE about their contacts with animals is relevant. PCR techniques are reference tools for diagnosis confirmation when valve or vertebral samples are available.

Long-term outcomes of transcatheter pulmonary valve implantation with melody and SAPIEN valves.

BACKGROUND: Transcatheter pulmonary valve implantation (TPVI) is effective for treating right ventricle outflow tract (RVOT) dysfunction. Factors associated with long-term valve durability remain to be investigated. METHODS: Consecutive patients successfully treated by TPVI with Melody valves (n = 32) and SAPIEN valves (n = 182) between 2008 and 2020 at a single tertiary centre were included prospectively and monitored. RESULTS: The 214 patients had a median age of 28 years (range, 10-81). The RVOT was a patched native pulmonary artery in 96 (44.8%) patients. Median follow-up was 2.8 years (range, 3 months-11.4 years). Secondary pulmonary valve replacement (sPVR) was performed in 23 cases (10.7%), due to stenosis (n = 22, 95.7%) or severe regurgitation (n = 1, 4.3%), yielding an incidence of 7.6/100 patient-years with melody valves and 1.3/100 patient-years with SAPIEN valves (P = 0.06). The 5- and 10-year sPVR-freedom rates were 78.1% and 50.4% with Melody vs. 94.3% and 82.2% with SAPIEN, respectively (P = 0.06). The incidence of infective endocarditis (IE) was 5.5/100 patient-years with Melody and 0.2/100 patient-years with SAPIEN (P < 0.0001). Factors associated with sPVR by univariate analysis were RV obstruction before TPVI (P = 0.04), transpulmonary maximal velocity > 2.7 m/s after TPVI (p = 0.0005), valve diameter ≤ 22 mm (P < 0.003), IE (P < 0.0001), and age < 25 years at TPVI (P = 0.04). By multivariate analysis adjusted for IE occurrence, transpulmonary maximal velocity remained associated with sPVR. CONCLUSIONS: TPVI is effective for treating RVOT dysfunction. Incidence of sPVR is higher in patients with residual RV obstruction or IE. IE add a substantial risk of TPVI graft failure and is mainly linked to the Melody valve. SOCIAL MEDIA ABSTRACT: Transcatheter pulmonary valve implantation is effective for treating right ventricular outflow tract dysfunction in patients with congenital heart diseases. Incidence of secondary valve replacement is higher in patients with residual obstruction or infective endocarditis.

Infective endocarditis after transcatheter pulmonary valve implantation in patients with congenital heart disease: Distinctive features.

The introduction of transcatheter pulmonary valve implantation (TPVI) has greatly benefited the management of right ventricular outflow tract dysfunction. Infective endocarditis (IE) is a feared complication of TPVI that affects valve durability and patient outcomes. Current recommendations provide only limited guidance on the management of IE after TPVI (TPVI-IE). This article, by a group of experts in congenital heart disease in children and adults, interventional cardiology, infectious diseases including IE, and microbiology, provides a comprehensive review of the current evidence on TPVI-IE, including its incidence, risk factors, causative organisms, diagnosis, and treatment. The incidence of TPVI-IE varies from 13-91/1000 person-years for Melody valves to 8-17/1000 person-years for SAPIEN valves. Risk factors include history of IE, DiGeorge syndrome, immunosuppression, male sex, high residual transpulmonary gradient and portal of bacteria entry. Staphylococci and streptococci are the most common culprits, whereas Staphylococcus aureus is associated with the most severe disease. In addition to the modified Duke criteria, a high residual gradient warrants a strong suspicion. Imaging studies are helpful for the diagnosis. Intravenous antibiotics guided by blood culture results are the mainstay of treatment. Invasive re-intervention may be required. TPVI-IE in patients with congenital heart disease exhibits several distinctive features. Whether specific valve types are associated with a higher risk of TPVI-IE requires further investigation. Patient and parent education regarding IE prevention may have a role to play and should be offered to all patients.

The Coris BioConcept COVID 19 Ag Respi-Strip, a field experience feedback.

This communication described how the Coris BioConcept COVID-19 Ag Respi-Strip test (Coris-Ag) was implemented in the workflow of our clinical microbiology laboratory for COVID-19 diagnosis. The diagnostic performance statistics (sensitivity, specificity) of the Coris-Ag were evaluated against a gold standard, the RealStar SARS-CoV-2 RT-PCR kit 1.0. Additionally, the effect of reading the Coris-Ag results at 30 min was compared to reading at 15 min. The Coris-Ag was performed on a total of 294 patients during two periods; 158 patients were tested during period 1 at the peak of the pandemic (April 6th to April 10th 2020) which returned a positivity rate of 17.1 %, and 136 patients during period 2 (April 12th to April 16th 2020) which returned a positivity rate of 11 %. Compared to the RT-PCR, the 15-minute Coris-Ag readings resulted in a sensitivity of 59.3 % with a 100 % specificity for the period 1 patients (n = 158) while the sensitivity decreased to 20 % for the period 2 patients (n = 136). The overall sensitivity was 38.1 % for both periods (n = 294). The corresponding 30-minute readings produced a 7 % increase in sensitivity with a specificity of 100 % (n = 294). The sensitivity of the strip test (15-min reading) for high viral loads (Ct <25) was 84.6 %.

Frequency of surface bacterial contamination in family physicians' offices.

OBJECTIVES: The environment is perceived as a potential source of healthcare-associated infections. While this infection source has been well studied in hospital settings, little data on the risk of contamination in general medical practice is available. We aimed to assess the frequency of environmental contamination in family practice (FP), and to describe pathogens isolated, at-risk surfaces, and factors associated with this contamination. PATIENTS AND METHODS: We conducted a cross-sectional point prevalence study over six months in 51 FP offices. In each office, six environmental samples were collected after and before consultations on high-touch surfaces (stethoscope, examination table, physician's desktop, blood pressure cuff, medical equipment tray, computer keyboard and mouse). RESULTS: A total of 580 samples were obtained. All offices were contaminated at any time with at least 2.5 colony forming units. The median rate of examination room bio-cleaning was twice a week. For all equipment and surfaces, a lower bacterial load was found before consultations when the last cleaning had occurred less than 24hours prior to testing. CONCLUSION: High environmental contamination was observed in FP offices. Less than one practice in five used an effective cleaning agent; family physicians' awareness of practice hygiene is an important step for prevention.

No significant difference between ceftriaxone and cefotaxime in the emergence of antibiotic resistance in the gut microbiota of hospitalized patients: A pilot study.

BACKGROUND: Ceftriaxone and cefotaxime share a similar antibacterial spectrum and similar indications but have different pharmacokinetic characteristics. Ceftriaxone is administered once daily and 40% of its clearance is by biliary elimination, whereas cefotaxime requires three administrations per day and shows less than 10% biliary elimination. The high biliary elimination of ceftriaxone suggests a greater impact of this antibiotic on the gut microbiota than cefotaxime. The objective of this study was to compare the impact of ceftriaxone and cefotaxime on the gut microbiota. METHODS: A prospective clinical trial was performed that included 55 patients treated with intravenous ceftriaxone (1 g/24 h) or cefotaxime (1 g/8 h) for at least 3 days. Three fresh stool samples were collected from each patient (days 0, 3, and 7 or at the end of intravenous treatment) to assess the emergence of third-generation cephalosporin (3GC)-resistant Enterobacteriaceae, carbapenem-resistant Enterobacteriaceae, Pseudomonas aeruginosa, toxigenic Clostridioides difficile, and vancomycin-resistant enterococci. RESULTS: The emergence of 3GC-resistant gram-negative enteric bacilli (Enterobacteriaceae) (5.9% vs 4.7%, p > 0.99), Enterococcus spp, and non-commensal microorganisms did not differ significantly between the groups. Both antibiotics reduced the counts of total gram-negative enteric bacilli and decreased the cultivable diversity of the microbiota, but the differences between the groups were not significant. CONCLUSION: No significant difference was observed between ceftriaxone and cefotaxime in terms of the emergence of resistance.

Evaluation of the Unyvero i60 ITI® multiplex PCR for infected chronic leg ulcers diagnosis.

OBJECTIVES: Unyvero i60 ITI multiplex PCR (mPCR) may identify a large panel of bacteria and antibiotic resistance genes. In this study, we compared results obtained by mPCR to standard bacteriology in chronic leg ulcer (CLU) infections. METHODS: A prospective study, part of the interventional-blinded randomized study "ulcerinfecte" (NCT02889926), was conducted at Saint Joseph Hospital in Paris. Fifty patients with a suspicion of infected CLU were included between February 2017 and September 2018. Conventional bacteriology and mPCR were performed simultaneously on deep skin biopsies. RESULTS: Staphylococcus aureus and Pseudomonas aeruginosa were the most detected pathogens. Regarding the global sensitivity, mPCR is not overcome to the standard culture. Anaerobes and slow growing bacteria were detected with a higher sensitivity rate by mPCR than standard culture. CONCLUSION: Unyvero i60 ITI multiplex PCR detected rapidly pathogenic bacteria in infected CLU especially anaerobes and slow growing bacteria and was particularly effective for patients previously treated with antibiotics.

Prospective evaluation of rapid antimicrobial susceptibility testing by disk diffusion on Mueller-Hinton rapid-SIR directly on blood cultures.

BACKGROUND: With the worldwide spread of antibiotic resistance, delivering antibiotic susceptibility test (AST) results in a timely manner represents a major challenge. In cases of sepsis, rapid AST may facilitate early optimization of empiric antibiotic therapy. Disc diffusion is a well-standardized AST method, however 16 to 24 h are required to achieve an overall AST profile according to antimicrobial societies. METHODS: In this prospective pilot study, we evaluated the performance of Mueller-Hinton-Rapid-SIR (MHR-SIR) agar after 6-8 h of incubation in comparison with standard MH agar after 16 h of incubation directly on positive blood cultures caused by Enterobacteriaceae and Staphylococcus aureus from routine clinical microbiology. A total of 133 positive blood samples including 110 Enterobacteriaceae (83%) and 23 Staphylococcus aureus (17%) were tested in parallel by two direct AST methods, each using EUCAST breakpoints. For each combination bacterium and antibiotic, we compared the categorical agreement and the correlation between the diameters obtained by MHR-SIR and by standard MH. RESULTS: Our results showed 97.7% categorical agreement for Enterobacteriaceae, with 1.4% minor errors, 0.4% major errors and 0.5% very major errors. For S. aureus, we observed 97.8% categorical agreement, 1.9% minor errors, 0.3% major errors and no very major errors. CONCLUSION: Our results showed excellent categorical agreement and correlations between diameters for MHR-SIR and standard MH methods. MHRSIR can predict the result of overall AST profile within 6-8 h with reliable results. AST is obtained on the same day the blood culture becomes positive, with a very moderate cost.