Bloodstream infections in older population: epidemiology, outcome, and impact of multidrug resistance.

Bloodstream infections (BSIs) among older patients are frequent with high rate of mortality. Infections with multidrug-resistant organisms (MDRO) are associated with higher mortality than with susceptible microorganisms. We aimed to evaluate the prevalence of MDRO infection during BSI in older population and the factors associated with unfavorable outcome. This study is a retrospective cohort of all BSI episodes occurring among older patients (> 65yo), from April 1, 2010, to December 31, 2016, in a French university hospital for geriatric medicine. A total of 255 BSI episodes were analyzed. Mean age was 86.3±6.5 years, and sex ratio (M/F) was 0.96. Main comorbidities were orthopedic device (26.7%), active neoplasia (24.3%), and diabetes mellitus (18.4%). Main primary sites of infection were urinary tract infections (56.9%), respiratory tract infections (10.6%), intra-abdominal infections (7.1%), and skin and soft tissue infections (4.7%). Main bacteria identified were Escherichia coli (45.1%), Staphylococcus aureus (14.1%), enterococci (10.7%), coagulase-negative staphylococci (CoNS) (5.5%), and streptococci (5.1%). MDROs were involved in 17.2% of BSI (gram-negative bacilli: 9.0%; CoNS: 4.3%; and methicillin-resistant S. aureus (MRSA): 3.9%). The main factor associated with MDRO BSI was colonization with MDRO (OR=6.29; 95%CI=2.9-14.32). Total mortality was 18.4% and significantly higher in case of initial severity (OR=3.83; 95%CI=1.75-8.38), healthcare-associated infection (OR=5.29; 95%CI=1.11-25.30), and MRSA BSI (OR=9.16; 95%CI=1.67-50.16). BSI due to MDRO is frequent in older population and is strongly associated with carriage of MDRO. Healthcare-associated BSI, severe episodes, and BSI due to MRSA are associated with unfavorable outcome. In these cases, a broad-spectrum antibiotic should be promptly initiated.

Measurement of Serum Anti-staphylococcal Antibodies Increases Positive Predictive Value of Preoperative Aspiration for Hip Prosthetic Joint Infection.

BACKGROUND: Preoperative synovial fluid culture is pivotal in the early diagnosis of prosthetic joint infection (PJI) but may yield false-positive and false-negative results. We evaluated the predictive value of synovial fluid culture results combined with the measurement of serum anti-staphylococcal antibodies (SASA). QUESTIONS/PURPOSES: (1) For hip and knee PJI, does combining positive SASA results with preoperative synovial culture results improve the positive predictive value (PPV) of preoperative synovial fluid culture alone? (2) Does combining preoperative synovial fluid culture results with a positive cell count and differential result increase the PPV of preoperative synovial fluid culture alone? (3) What proportion of isolated organisms exhibit concordance in antibiotic susceptibility: preoperative aspiration versus intraoperative isolates? METHODS: A prospective study was conducted at two French reference centers that manage bone and joint infections and included 481 adult patients who had a revision or resection arthroplasty between June 25, 2012 and June 23, 2014. Exclusion criteria including no serum sample available for immunoassay, the lack of microbiological documentation, and the absence of preoperative aspiration reduced the patient number to 353. Seven patients with an undetermined SASA result were excluded from the analysis. We also excluded patients with PJI involving more than one Staphylococcus species (polystaphylococcal infection) and those in whom more than one Staphylococcus species was recovered from the preoperative synovial fluid culture (polystaphylococcal synovial fluid culture). In total, 340 patients were included in the analysis (no infection, 67% [226 of 340]; staphylococcal infection, 21% [71 of 340]; other infection, 13% [43 of 340]). The preoperative synovial fluid analysis included a cell count and differential and bacterial culture. SASAs were measured using a multiplex immunoassay. The diagnosis of PJI was determined using the Infectious Diseases Society of America (IDSA) criteria [] and intraoperative tissue culture at the time of revision surgery was used as the gold standard (at least one positive intraoperative sample for a "virulent" organism (such as S. aureus) or two positive samples for a "non-virulent" (for example S. epidermidis). RESULTS: SASA increased the PPV compared with synovial fluid culture alone (92% [95% CI 82 to 97] versus 79% [95% CI 68 to 87]; p = 0.04); when stratified by site, an increase in PPV was seen in hip infections (100% [95% CI 89 to 100] versus 77% [95% CI 63 to 88]; p = 0.01) but not in knee infections (84% [95% CI 66 to 95] versus 80% [95% CI 64 to 91]; p = 0.75). A positive cell count and differential result increased the PPV of staphylococcal synovial fluid cultures compared with synovial fluid culture alone (86% [95% CI 70 to 95] versus 79% [95% CI 68 to 87]; p = 0.36); when stratified by site, no difference in hip and knee infections was observed (86% [95% CI 67 to 96] versus 77% [95% CI 63 to 88]; p = 0.42) and 86% [95% CI 70 to 95] versus 80% [95% CI 64 to 91]; p = 0.74). CONCLUSION: SASA measurement improves the predictive value of synovial fluid cultures of the hip for all staphylococcal organisms, including coagulase-negative staphylococci, but the PPV of SASA plus synovial fluid culture it is not superior to the PPV of synovial fluid cell count/differential plus synovial culture for the knee. LEVEL OF EVIDENCE: Level III, diagnostic study.

Molecular Typing of Multiple Isolates Is Essential to Diagnose Cutibacterium acnes Orthopedic Device-related Infection.

Cutibacterium acnes orthopedic device-related infections (ODRIs) range from obvious infections to solely culture-based diagnoses. Multilocus sequence typing of multiple isolates from the same procedure revealed that most cases with normal C-reactive protein levels that were classified as C. acnes ODRI would be considered contaminations when accounting for genotypic data.

Monomicrobial bone and joint infection due to Corynebacterium striatum: literature review and amoxicillin-rifampin combination as treatment perspective.

Corynebacterium striatum is a ubiquitous colonizer of human skin and mucous membranes. It is increasingly involved in infections, especially with prosthetic devices or in immunocompromised individuals. Microbiological diagnosis is challenging and bacterial resistance is a major concern. We performed a retrospective study of monomicrobial bone and joint infections (BJI) due to C. striatum in two referral centers from April 2012 to July 2017. We collected the patients' clinical and microbiological characteristics and outcomes. We also performed a literature review of BJI due to C. striatum. We identified 12 cases (nine prosthetic joint infections, one osteosynthetic device infection, one non-union, and one arthritis) in 11 patients, five of which were immunocompromised. Microbiological diagnosis was performed with prolonged culture media. Ten out of 12 strains were susceptible to aminopenicillin, a drug class not recommended for testing by the EUCAST/CASFM guidelines, and 8/12 patients were treated with amoxicillin-rifampicin. The cure rate was 8/12, after a median follow-up period of 487.5 days (IQR 140.3-1348.5). Twelve cases of BJI due to C. striatum were previously reported. Among them, 5/12 patients were immunocompromised, 3/12 cases were acute BJI, and 2/12 were device-related infections. The diagnosis was performed by PCR in one case, and 10/12 patients were treated with glycolipopeptides, with a cure rate of 11/12. We report the largest cohort of monomicrobial BJI with C. striatum. Determination of aminopenicillin susceptibility is essential since it is frequently active in our experience, even in BJI. The cure rate of this infection seems high.

Treatment of bone and joint infections by ceftazidime/avibactam and ceftolozane/tazobactam: a cohort study.

OBJECTIVES: Ceftazidime/avibactam (C/A) and ceftolozane/tazobactam (C/T) are two novel antibacterials with known efficacy against Gram-negative bacteria (GNB). We aimed to describe the efficacy and safety of surgical management combined with C/A or C/T treatment for bone and joint infections (BJIs). METHODS: We conducted an observational, bicentric study of patients treated with C/A or C/T for a BJI between May 2016 and June 2019. Failure was defined as the need for unplanned additional antibiotic treatment or orthopaedic surgery, or death due to the BJI up to the patient's latest visit. RESULTS: Overall, 15 patients were included. Nine patients were treated with C/A, mainly for polymicrobial BJI due to multidrug-resistant (MDR) bacteria (Enterobacteriaceae, n = 7). Six patients were male, the median age was 66 years and the median Charlson comorbidity index (CCI) was 5. It was the first septic episode at the site in 3/9 patients. The cure rate was 7/9 (median follow-up, 272 days). Two patients showed C/A-related confusion. Five patients were treated with C/T for BJI involving MDR Pseudomonas aeruginosa. Four patients were male, the median age was 53 years and the median CCI was 2. All patients had previous septic episodes at the infection site. The cure rate was 3/5 (median follow-up, 350 days). One patient was successfully treated by C/T then C/A for multistage spondylodiscitis. CONCLUSION: In our experience, C/A and C/T are two effective and safe options, even as salvage treatment for BJI due to MDR-GNB despite the absence of label, however more data are warranted.

Efficacy and safety of subcutaneous administration of ceftazidime as a salvage therapy in geriatrics: a case report.

Ceftazidime is a third-generation cephalosporin used for the treatment of Gram-negative bacteria only approved for parenteral use by intravenous and intramuscular route. In some clinical situations, off-label subcutaneous injection could be a salvage route for the administration of antibiotics, especially in geriatrics, despite the paucity of evidence about efficacy and safety. We report a case of a successful and well-tolerated subcutaneous ceftazidime therapy in a 90-year-old woman for the treatment of an acute urinary tract infection caused by Pseudomonas aeruginosa with therapeutic drug monitoring data.

Clinical Cutaneous Features of Patients Infected With SARS-CoV-2 Hospitalized for Pneumonia: A Cross-sectional Study.

BACKGROUND: Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is the cause of a current pandemic worldwide. This virus can reach all organs and disturbs the immune system, leading to a cytokine storm in severe forms. We aimed to report cutaneous features among coronavirus disease 2019 (COVID-19) hospitalized patients. METHODS: We performed a cross-sectional study on 1 given day among all patients hospitalized in acute care for COVID-19 and included all patients with cutaneous features. Follow-up 48 hours later was obtained. RESULTS: Among 59 adult patients hospitalized on the day of the study in an infectious diseases ward for SARS-CoV-2 infection who were confirmed by molecular assay and/or radiological findings (computed tomography scan), 40 were included. Several cutaneous manifestations were found: macular exanthema (80%), face edema (32%), livedo (13%), urticarial rash (8%), purpura (5%), oral lichenoid lesions (33%), and conjunctivitis (18%). Cutaneous biopsy was performed in 17 patients. Histological findings showed mast cell hyperplasia (100%), superficial perivascular infiltrate of lymphocytes (94%), and superficial edema (47%) consistent with capillary leak. CONCLUSIONS: Various dermatological signs can be encountered during COVID-19. A macular rash was the most frequent. All cutaneous features could be related to a vascular leak process.

Multiplex Antibody Measurement for Post-treatment Follow-up of Staphylococcal Prosthetic Joint Infection: A Diagnostic Pilot Study.

Introduction: Multiplex-antibody detection has been recently proposed for the noninvasive diagnosis of staphylococcal prosthetic joint infection (PJI). We evaluated this approach for the post-treatment follow-up of patients. Methods: Nineteen cases of staphylococcal PJI were prospectively followed for one year after treatment. The IgG response against eight staphylococcal antigens was measured before surgery and one year post-surgery using Luminex technology (Austin, TX, USA); median fluorescence intensity values determined for each antigen were transformed into a "Total Response Index" (TRI). Results: Patients (11 women/8 men) had a mean (SD) age of 72.2 (12.4) years. Site of prosthesis was the knee (n=10), the hip (n=8) and the shoulder (n=1). Ten patients were infected by S. epidermidis, six by S. aureus, and three by S. lugdunensis. TRI values at one year were significantly lower than pre-surgery values (mean [SD]: 5.9 [1.8] versus 8.1 [3.4], p=0.02) and decreased, on average, by 21.2%. TRI values markedly increased in two patients. One patient had a relapse of S. aureus PJI at five months post-surgery, with a 37% increase of the TRI. The other had septic failure three months after revision for S. lugdunensis PJI; all intraoperative samples remained culture-negative, but the TRI increased by 51% and the antibody profile showed a marked change, suggesting a reinfection with another staphylococcal species. Conclusion: Multiplex-antibody measurement may be useful for the follow-up of staphylococcal PJI and may help to detect septic failure involving organisms targeted by the assay.