Comparison of prophylaxis and preemptive strategy as cytomegalovirus prevention in liver transplant recipients.

OBJECTIVES: Prophylaxis (P) or pre-emptive strategy (PS) in high-risk liver transplant recipients (LTRs) are either recommended. We compared the results of each strategy. METHODS: Two groups of LTR transplanted during two consecutive periods were compared. Only cytomegalovirus (CMV)-mismatched LTR (Donor +/ Recipient -) were included. The primary endpoints were: the onset of polymerase chain reaction-based DNAemia and the proportion of patients with CMV disease. A number of episodes of CMV infection, antiviral therapy, ganciclovir resistance, infectious or immunological complications, cost of both strategies, and survival (1, 5, and 10 years) were also compared. RESULTS: Forty-eight and 60 patients were respectively included in the P and PS groups. Eighteen (38%) in the P group and 56 (93%) in the PS group had CMV DNAemia (p <.0001) with a similar CMV disease rate (16.7% and 15%). Duration of curative therapy was longer in the PS group: 91 days versus 16 (p <.0001). Acute rejection was less frequent (p = .04) and more patients experienced a ganciclovir-resistant CMV infection in the PS group (10% vs. 0, p = .03). The drug-associated cost of PS was higher (10 004 vs. 4804€) and the median number of rehospitalization days tended to be higher (6 vs. 4, p = .06). Survival at any time was similar. CONCLUSION: We reported more CMV DNAemias and ganciclovir-resistant CMV events with PS. The cost of the PS strategy was higher.

Differential response to antibiotic therapy in staphylococcal infective endocarditis: contribution of an ex vivo model.

OBJECTIVES: Staphylococcal infective endocarditis (IE) remains a hard-to-treat infection with high mortality. Both the evaluation of new innovative therapies and research on alternative models mimicking human IE are therefore urgently needed to improve the prognosis of patients with diagnosed IE. Dalbavancin is a novel anti-staphylococcal lipoglycopeptide but there are limited data supporting its efficacy on biofilm infections. This antibiotic could be an alternative to current therapies for the medical treatment of IE but it needs to be further evaluated. METHODS: Here we developed an original ex vivo model of Staphylococcus aureus IE on human heart valves and assessed biofilm formation on them. After validating the model, the efficacy of two antistaphylococcal antibiotics, vancomycin and dalbavancin, was compared by measuring and visualizing their respective ability to inhibit and eradicate late-formed biofilm. RESULTS: Determination of the minimum biofilm inhibitory (MbIC) and eradicating (MbEC) concentrations in our ex vivo model identified dalbavancin as a promising drug with much lower MbIC and MBEC than vancomycin (respectively <0.01 versus 28 mg/L and 0.03 versus 32 mg/L). CONCLUSIONS: These data highlight a strong bactericidal effect of dalbavancin, particularly on an infected heart valve compared with vancomycin. Dalbavancin could be a realistic alternative treatment for the management of staphylococcal IE.

Dalbavancin plasma concentrations in 133 patients: a PK/PD observational study.

OBJECTIVES: Limited pharmacokinetics data support dalbavancin long-term use in off-label indications and the optimal dosing regimen is debated. We aimed to describe dalbavancin concentrations in an observational retrospective multicentre study. METHODS: Patients from 13 French hospitals, treated with 1500 mg doses of dalbavancin and for whom therapeutic drug monitoring was performed from June 2018 to March 2021 were included. Dalbavancin plasma concentrations were described at peak and 1, 2, 3, 4, 6 and 8 weeks after the last 1500 mg dose. Concentrations in patients weighing more or less than 75 kg and with a GFR greater or less than 60 mL/min were compared. Microbiological data were collected and dalbavancin MIC was measured when possible. RESULTS: One hundred and thirty-three patients were included (69% treated for bone and joint infections, 16% for endocarditis). Thirty-five patients received a single dose of dalbavancin and 98 received several administrations. Two, 3 and 4 weeks after the last dose, median plasma concentrations were respectively 25.00, 14.80 and 9.24 mg/L for the first doses and 34.55, 22.60 and 19.20 mg/L for the second or subsequent doses. Weight and renal function had an impact on pharmacokinetics. Infection was documented in 105 patients (Staphylococcus spp. in 68% of cases). Staphylococcus aureus was isolated in 32.5% of cases (median MIC: 0.047 mg/L) and Staphylococcus epidermidis in 27% of cases (median MIC of 0.047 mg/L). CONCLUSIONS: Plasma concentrations of dalbavancin were consistent with those described in clinical trials and those sought during the industrial development of the molecule.

The use of TNF-α antagonists in tuberculosis to control severe paradoxical reaction or immune reconstitution inflammatory syndrome: a case series and literature review.

Paradoxical reaction (PR) and immune reconstitution inflammatory syndrome (IRIS) are common complications of tuberculosis treatment. Corticosteroids are first-line treatment for severe PR or IRIS, particularly neurological. We report four cases of severe PR or IRIS during tuberculosis treatment who required TNF-α antagonists, and identified 20 additional cases through literature review. They were 14 women and 10 men, with a median age of 36 years (interquartile range, 28-52). Twelve were immunocompromised before tuberculosis: untreated HIV infection (n=6), or immunosuppressive treatment (TNF-α antagonists, n=5; tacrolimus, n=1). Tuberculosis was mostly neuromeningeal (n=15), pulmonary (n=10), lymph node (n=6), and miliary (n=6), multi-susceptible in 23 cases. PR or IRIS started after a median time of 6 weeks (IQR, 4-9) following anti-tuberculosis treatment start, and consisted primarily of tuberculomas (n=11), cerebral vasculitis (n=8), and lymphadenitis (n=6). First-line treatment of PR or IRIS was high-dose corticosteroids in 23 cases. TNF-α antagonists were used as salvage treatment in all cases, with infliximab (n=17), thalidomide (n=6), and adalimumab (n=3). All patients improved, but 6 had neurological sequelae, and 4 had TNF-α antagonist-related severe adverse events. TNF-α antagonists are safe and effective as salvage or corticosteroid-sparing therapeutic for severe PR or IRIS during tuberculosis treatment.

Persistent headaches one year after bacterial meningitis: prevalence, determinants and impact on quality of life.

BACKGROUND: Little is known on headaches long-term persistence after bacterial meningitis and on their impact on patients' quality of life. METHODS: In an ancillary study of the French national prospective cohort of community-acquired bacterial meningitis in adults (COMBAT) conducted between February 2013 and July 2015, we collected self-reported headaches before, at onset, and 12 months (M12) after meningitis. Determinants of persistent headache (PH) at M12, their association with M12 quality of life (SF 12), depression (Center for Epidemiologic Studies Depression Scale) and neuro-functional disability were analysed. RESULTS: Among the 277 alive patients at M12 87/274 (31.8%), 213/271 (78.6%) and 86/277 (31.0%) reported headaches before, at the onset, and at M12, respectively. In multivariate analysis, female sex (OR: 2.75 [1.54-4.90]; p < 0.001), pre-existing headaches before meningitis (OR: 2.38 [1.32-4.30]; p < 0.01), higher neutrophilic polynuclei percentage in the CSF of the initial lumbar puncture (OR: 1.02 [1.00-1.04]; p < 0.05), and brain abscess during the initial hospitalisation (OR: 8.32 [1.97-35.16]; p < 0.01) were associated with M12 persistent headaches. Neither the responsible microorganism, nor the corticoids use were associated with M12 persistent headaches. M12 neuro-functional disability (altered Glasgow Outcome Scale; p < 0.01), M12 physical handicap (altered modified Rankin score; p < 0.001), M12 depressive symptoms (p < 0.0001), and M12 altered physical (p < 0.05) and mental (p < 0.0001) qualities of life were associated with M12 headaches. CONCLUSION: Persistent headaches are frequent one year after meningitis and are associated with quality of life alteration. CLINICAL TRIAL: NCT01730690.

atpE Mutation in Mycobacterium tuberculosis Not Always Predictive of Bedaquiline Treatment Failure.

We report the emergence of an atpE mutation in a clinical Mycobacterium tuberculosis strain. Genotypic and phenotypic bedaquiline susceptibility testing displayed variable results over time and ultimately were not predictive of treatment outcome. This observation highlights the limits of current genotypic and phenotypic methods for detection of bedaquiline resistance.

Diffusion of amoxicillin into heart valves from infective endocarditis patients.

OBJECTIVES: Amoxicillin is the drug of choice in the management of streptococcal and enterococcal infective endocarditis (IE) but little is known regarding amoxicillin diffusion into infected heart valves. Herein, we assessed amoxicillin valvular distribution and related pharmacokinetic/pharmacodynamic (PK/PD) target attainment in IE patients undergoing heart valve surgery. PATIENTS AND METHODS: In this 2-year prospective study, patients with IE treated by continuous infusion of amoxicillin and undergoing a surgical valve replacement were included. Both amoxicillin plasma and tissue concentrations were measured the day of surgery. Amoxicillin concentration in plasma and crushed heart valves were measured by a validated liquid chromatography method coupled with ultra-violet and tandem mass spectrometry, respectively. MIC and MBC of amoxicillin were determined for all available isolates. The rate of achievement of PK/PD efficacy parameters were assessed. RESULTS: Twenty-two heart valves were removed from 20 patients. Bacterial aetiology was streptococcal (n = 17) and enterococcal (n = 3). Amoxicillin mean daily dose was 12 ±â€Š3 g/24 h, mean plasma concentration was 29 ±â€Š21 mg/L (n = 15), mean tissue concentration was 23 ±â€Š15 mg/L (n = 22). Median diffusion rate was 62%. Patients reached a plasma concentration target >4XCMI (n = 13). Tissue concentrations were bactericidal for all streptococcal IE but not for enterococcal IE. CONCLUSIONS: Amoxicillin intravalvular measurements in IE treated patients showed significant penetration into the infectious site. These data are reassuring that in situ bactericidal concentrations can be largely achieved in the management of streptococcal IE and support the need for combination antibiotic therapy for enterococcal IE.

Is Rifampin Use Associated With Better Outcome in Staphylococcal Prosthetic Valve Endocarditis? A Multicenter Retrospective Study.

BACKGROUND: International guidelines recommend rifampin-based combinations for staphylococcal prosthetic valve endocarditis (PVE). However, no robust clinical data support this recommendation, and rifampin tolerability is an issue. We aimed to evaluate the impact of rifampin for the treatment of staphylococcal PVE. METHODS: An observational retrospective cohort study of all adults with staphylococcal PVE (modified Duke criteria) was conducted in 3 referral centers for endocarditis, during years 2000-2018. Primary outcome measurement was 1-year mortality. RESULTS: We enrolled 180 patients with PVE due to Staphylococcus aureus (n = 114, 63.3%), or coagulase-negative staphylococci (n = 66, 36.7%), on bioprosthesis (n = 111, 61.7%), mechanical valve (n = 67, 37.2%), or both (n = 2). There were 132 males (73.3%), and mean age was 70.4 ± 12.4 years. Valvular surgery was performed in 51/180 (28.3%) cases. Despite all isolates were susceptible to rifampin, only 101 (56.1%) were treated with rifampin, for a median duration of 33.0 days, whereas 79 (43.9%) received no rifampin. Baseline characteristics were similar in both groups. One-year mortality was, respectively, 37.6% (38/101), and 31.6% (25/79), in patients treated with, or without, rifampin (P = .62). Relapse rates were 5.9% (6/101), and 8.9% (7/79), P = .65. Patients treated with rifampin had longer hospital length-of-stay: 42.3 ± 18.6 vs 31.3 ± 14.0 days (P < .0001). On multivariate analysis, only cerebral emboli (odds ratio [OR] 2.95, 95% confidence interval [CI], 1.30-6.70, P = .009), definite endocarditis (OR 7.15, 95% CI, 1.47-34.77, P = .018), and methicillin-resistant S. aureus (OR 6.04, 95% CI, 1.34-27.26, P = .019), were associated with 1-year mortality. CONCLUSIONS: A large proportion (43.9%) of staphylococcal PVE received no rifampin. One-year survival and relapse rates were similar in patients treated with or without rifampin.

Impact of Systematic Whole-body 18F-Fluorodeoxyglucose PET/CT on the Management of Patients Suspected of Infective Endocarditis: The Prospective Multicenter TEPvENDO Study.

BACKGROUND: Diagnostic and patients' management modifications induced by whole-body 18F-FDG-PET/CT had not been evaluated so far in prosthetic valve (PV) or native valve (NV) infective endocarditis (IE)-suspected patients. METHODS: In sum, 140 consecutive patients in 8 tertiary care hospitals underwent 18F-FDG-PET/CT. ESC-2015-modified Duke criteria and patients' management plan were established jointly by 2 experts before 18F-FDG-PET/CT. The same experts reestablished Duke classification and patients' management plan immediately after qualitative interpretation of 18F-FDG-PET/CT. A 6-month final Duke classification was established. RESULTS: Among the 70 PV and 70 NV patients, 34 and 46 were classified as definite IE before 18F-FDG-PET/CT. Abnormal perivalvular 18F-FDG uptake was recorded in 67.2% PV and 24.3% NV patients respectively (P < .001) and extracardiac uptake in 44.3% PV and 51.4% NV patients. IE classification was modified in 24.3% and 5.7% patients (P = .005) (net reclassification index 20% and 4.3%). Patients' managements were modified in 21.4% PV and 31.4% NV patients (P = .25). It was mainly due to perivalvular uptake in PV patients and to extra-cardiac uptake in NV patients and consisted in surgery plan modifications in 7 patients, antibiotic plan modifications in 22 patients and both in 5 patients. Altogether, 18F-FDG-PET/CT modified classification and/or care in 40% of the patients (95% confidence interval: 32-48), which was most likely to occur in those with a noncontributing echocardiography (P < .001) or IE classified as possible at baseline (P = .04), while there was no difference between NV and PV. CONCLUSIONS: Systematic 18F-FDG-PET/CT did significantly and appropriately impact diagnostic classification and/or IE management in PV and NV-IE suspected patients. CLINICAL TRIALS REGISTRATION: NCT02287792.

SARS-CoV-2-Induced ARDS Associates with MDSC Expansion, Lymphocyte Dysfunction, and Arginine Shortage.

PURPOSE: The SARS-CoV-2 infection can lead to a severe acute respiratory distress syndrome (ARDS) with prolonged mechanical ventilation and high mortality rate. Interestingly, COVID-19-associated ARDS share biological and clinical features with sepsis-associated immunosuppression since lymphopenia and acquired infections associated with late mortality are frequently encountered. Mechanisms responsible for COVID-19-associated lymphopenia need to be explored since they could be responsible for delayed virus clearance and increased mortality rate among intensive care unit (ICU) patients. METHODS: A series of 26 clinically annotated COVID-19 patients were analyzed by thorough phenotypic and functional investigations at days 0, 4, and 7 after ICU admission. RESULTS: We revealed that, in the absence of any difference in demographic parameters nor medical history between the two groups, ARDS patients presented with an increased number of myeloid-derived suppressor cells (MDSC) and a decreased number of CD8pos effector memory cell compared to patients hospitalized for COVID-19 moderate pneumonia. Interestingly, COVID-19-related MDSC expansion was directly correlated to lymphopenia and enhanced arginase activity. Lastly, T cell proliferative capacity in vitro was significantly reduced among COVID-19 patients and could be restored through arginine supplementation. CONCLUSIONS: The present study reports a critical role for MDSC in COVID-19-associated ARDS. Our findings open the possibility of arginine supplementation as an adjuvant therapy for these ICU patients, aiming to reduce immunosuppression and help virus clearance, thereby decreasing the duration of mechanical ventilation, nosocomial infection acquisition, and mortality.

CSF concentration of cefotaxime in adult patients with pneumococcal meningitis: a multicentre retrospective study.

BACKGROUND AND OBJECTIVES: Pneumococcal meningitis is a devastating disease that requires adequate meningeal antibiotic penetration to limit the mortality. Despite a large usage in this indication, data about CSF concentration of cefotaxime during pneumococcal meningitis in adults are scarce. Therefore, we aimed to describe the CSF concentration obtained after high-dose cefotaxime administration in adult patients treated for Streptococcus pneumoniae meningitis. PATIENTS AND METHODS: In this multicentre, observational, retrospective study, cases of adult patients with S. pneumoniae meningitis hospitalized between January 2013 and October 2019 for whom cefotaxime concentration was measured in CSF were reviewed. RESULTS: Cefotaxime concentration was analysed in 44 CSF samples collected among 31 patients. Median (IQR) age was 61 years (52-69). Dexamethasone was administered in 27 subjects. Median (IQR) cefotaxime daily dosage was 15 g (12-19), corresponding to 200 mg/kg (150-280). CSF samples were collected approximately 5 days after cefotaxime initiation. Median (IQR, range) cefotaxime CSF concentration was 10.3 mg/L (4.8-19.3, 1.2-43.4). Median (range) MIC for Streptococcus pneumoniae was 0.25 mg/L (0.008-1) (n = 22). The median (IQR, range) CSF/MIC ratio was 38 (12-146, 4-1844). Twenty-five CSF concentrations (81%) were above 10 times the MIC. Cefotaxime was discontinued in two patients for toxicity. In-hospital mortality rate was 29%. CONCLUSIONS: Adult patients with pneumococcal meningitis treated with a high dose of cefotaxime (200 mg/kg/day) had elevated CSF concentrations with satisfying pharmacokinetics/pharmacodynamics parameters and tolerability profile. This study brings reassuring pharmacological data regarding the use of high-dose cefotaxime monotherapy for treating pneumococcal meningitis with susceptible strains to cefotaxime.

Prevalence and characteristics of persistent symptoms after non-severe COVID-19: a prospective cohort study.

We performed a prospective cohort study of 311 outpatients with non-severe COVID-19 (187 women, median age 39 years). Of the 214 (68.8%) who completed the 6-week follow-up questionnaire, 115 (53.7%) had recovered. Others mostly reported dyspnea (n = 86, 40.2%), weight loss (n = 83, 38.8%), sleep disorders (n = 68, 31.8%), and anxiety (n = 56, 26.2%). Of those who developed ageusia and anosmia, these symptoms were still present at week 6 in, respectively, 11/111 (9.9%) and 19/114 (16.7%). Chest CT scan and lung function tests found no explanation in the most disabled patients (n = 23). This study confirms the high prevalence of persistent symptoms after non-severe COVID-19.

The emergence of Staphylococcus aureus as the primary cause of cardiac device-related infective endocarditis.

BACKGROUND: Increasing use of cardiovascular implantable electronic devices (CIED), as permanent pacemakers (PPM), implantable cardioverter defibrillators (ICD), or cardiac resynchronization therapy (CRT), is associated with the emergence of CIED-related infective endocarditis (CIED-IE). We aimed to characterize CIED-IE profile, temporal trends, and prognostic factors. METHODS: CIED-IE diagnosed at Rennes University Hospital during years 1992-2017 were identified through computerized database, and included if they presented all of the following: (1) clinical signs of infection; (2) microbiological documentation through blood and/or CIED lead cultures; (3) lead or valve vegetation, or definite IE according to Duke criteria. Data were retrospectively extracted from medical charts. The cohort was categorized in three periods: 1992-1999, 2000-2008, and 2009-2017. RESULTS: We included 199 patients (51 women, 148 men, median age 73 years [interquartile range, 64-79]), with CIED-IE: 158 PPMs (79%), 24 ICD (12%), and 17 CRT (9%). Main pathogens were coagulase-negative staphylococci (CoNS: n = 86, 43%), Staphylococcus aureus (n = 60, 30%), and other Gram-positive cocci (n = 28, 14%). Temporal trends were remarkable for the decline in CoNS (P = 0.002), and the emergence of S. aureus as the primary cause of CIED-IE (24/63 in 2009-2017, 38%). Factors independently associated with one-year mortality were chronic obstructive pulmonary disease (COPD: hazard ratio 3.84 [1.03-6.02], P = 0.03), left-sided endocarditis (HR 2.25 [1.09-4.65], P = 0.03), pathogens other than CoNS (HR 3.16 [1.19-8.39], P = 0.02), and CIED removal/reimplantation (HR 0.41 [0.20-0.83], P = 0.01). CONCLUSIONS: S. aureus has emerged as the primary cause of CIED-IE. Left-sided endocarditis, COPD, pathogens other than CoNS, and no CIED removal/reimplantation are independent risk factors for one-year mortality.

Use of rifampicin and graft removal are associated with better outcomes in prosthetic vascular graft infection.

OBJECTIVES: Prosthetic vascular graft infection (PVGI) is a very severe disease. We aimed to determine the factors associated with treatment failure. METHODS: Patients admitted to two University Hospitals with PVGI were included in this retrospective study. PVGI was classified as possible, probable or proven according to an original set of diagnostic criteria. We defined treatment failure if one of the following events occurred within the first year after PVGI diagnosis: death and infection recurrence due to the same or another pathogen. RESULTS: One hundred and twelve patients were diagnosed with possible (n = 26), probable (n = 22) and proven (n = 64) PVGI. Bacterial documentation was obtained for 81% of patients. The most frequently identified pathogen was Staphylococcus aureus (n = 39). Surgery was performed in 96 patients (86%). Antibiotics were administered for more than 6 weeks in 41% of patients. Treatment failure occurred in 30 patients (27.5%). The factors associated with a lower probability of treatment failure were total removal of the infected graft (OR = 0.2, 95% CI [0.1-0.6]), rifampicin administration (OR = 0.3 [0.1-0.9]) and possible PVGI according to the GRIP criteria (OR = 0.3 [0.1-0.9]). CONCLUSIONS: Treatment failure occurred in 27.5% of patients with PVGI. Total removal of the infected graft and rifampicin administration were associated with better outcomes.

Long-term Outcome of Patients With Nonoperated Prosthetic Valve Infective Endocarditis: Is Relapse the Main Issue?

In nonoperated prosthetic valve endocarditis (PVE), long-term outcome is largely unknown. We report the follow-up of 129 nonoperated patients with PVE alive at discharge. At 1 year, the mortality rate was 24%; relapses and reinfection were rare (5% each). Enterococcal PVE was associated with a higher risk of relapse.

COVID-19 in Patient with Sarcoidosis Receiving Long-Term Hydroxychloroquine Treatment, France, 2020.

Because of in vitro studies, hydroxychloroquine has been evaluated as a preexposure or postexposure prophylaxis for coronavirus disease (COVID-19) and as a possible COVID-19 curative treatment. We report a case of COVID-19 in a patient with sarcoidosis who was receiving long-term hydroxychloroquine treatment and contracted COVID-19 despite adequate plasma concentrations.

Risk of Progressive Multifocal Leukoencephalopathy in the Combination Antiretroviral Therapy Era in the French Hospital Database on Human Immunodeficiency Virus (ANRS-C4).

Background: Risk factors for progressive multifocal leukoencephalopathy (PML) in individuals with human immunodeficiency virus (HIV) infection are poorly documented in the era of combination antiretroviral therapy (cART). Methods: We studied HIV-1-infected individuals aged ≥15 years who had no history of PML and were prospectively followed up between 1997 and 2011 in the French Hospital Database on HIV (FHDH-ANRS CO4) cohort. Cox models were used to calculate adjusted hazard ratios (HRs), focusing on sub-Saharan origin, suggested to be protective, and recent cART initiation, potentially associated with an increased risk of PML. Results: PML developed in 555 individuals, in 57 during the first 6 months of cART. From 1997-2000 to 2009-2011, the incidence fell from 1.15 (95% confidence interval [CI], .98-1.31) to 0.49 (.37-.61) per 1000 person-years. Sub-Saharan African origin had no clear influence (HR, 0.80; 95% CI, .58-1.11). Compared with men who have sex with men, injection drug users (IDUs) were at higher risk (HR, 1.80 [95% CI, 1.32-2.45] for male and 1.68 [1.13-2.48] for female IDUs). When IDUs were excluded, hepatitis C virus seropositivity was associated with an increased risk (HR, 1.40; 95% CI, 1.02-1.93). Compared with no cART initiation, initiation <6 months previously was associated with PML onset (HR, 4.91; 95% CI, 2.42-9.95). Conclusions: Recent cART initiation is associated with an increased risk of PML, as are injection drug use and hepatitis C virus seropositivity. Sub-Saharan African origin had no protective effect.

Live intramacrophagic Staphylococcus aureus as a potential cause of antibiotic therapy failure: observations in an in vivo mouse model of prosthetic vascular material infections.

Objectives: To evaluate the significant role played by biofilms during prosthetic vascular material infections (PVMIs). Methods: We developed an in vivo mouse model of Staphylococcus aureus PVMI allowing its direct observation by confocal microscopy to describe: (i) the structure of biofilms developed on Dacron® vascular material; (ii) the localization and effect of antibiotics on these biostructures; and (iii) the interaction between bacteria and host tissues and cells during PVMI. Results: In this model we demonstrated that the biofilm structures are correlated to the activity of antibiotics. Furthermore, live S. aureus bacteria were visualized inside the macrophages present at the biofilm sites, which is significant as antibiotics do not penetrate these immune cells. Conclusions: This intracellular situation may explain the limited effect of antibiotics and also why PVMIs can relapse after antibiotic therapy.

Staphylococcus aureus Regulatory RNAs as Potential Biomarkers for Bloodstream Infections.

Staphylococcus aureus is a commensal bacterium and pathogen. Identifying biomarkers for the transition from colonization to disease caused by this organism would be useful. Several S. aureus small RNAs (sRNAs) regulate virulence. We investigated presence and expression of 8 sRNAs in 83 S. aureus strains from 42 patients with sepsis or septic shock and 41 asymptomatic colonized carriers. Small pathogenicity island sRNAs sprB and sprC were clade specific. Six sRNAs had variable expression not correlated with clinical status. Expression of RNAIII was lower in strains from septic shock patients than in strains from colonized patients. When RNAIII was associated with expression of sprD, colonizing strains could be discriminated from strains in patients with bloodstream infections, including patients with sepsis and septic shock. Isolates associated with colonization might have sRNAs with target expression different from those of disease isolates. Monitoring expression of RNAIII and sprD could help determine severity of bloodstream infections.