Prevention of ICU-acquired infection with decontamination regimen in immunocompromised patients: a pre/post observational study.

PURPOSE: Although the proportion of immunocompromised patients admitted to the ICU is increasing, data regarding specific management, including acquired infection (ICU-AI) prophylaxis, in this setting are lacking. We aim to investigate the effect of multiple-site decontamination regimens (MSD) in immunocompromised patients. METHODS: We conducted a prospective pre-/post-observational study in 2 ICUs in Bretagne, western France. Adults who required mechanical ventilation for 24 h or more were eligible. During the study period, MSD was implemented in participating ICUs in addition to standard care. It consists of the administration of topical antibiotics (gentamicin, colistin sulfate, and amphotericin B), four times daily in the oropharynx and the gastric tube, 4% chlorhexidine bodywash once daily, and a 5-day nasal mupirocin course. RESULTS: Overall, 295 immunocompromised patients were available for analysis (151 in the post-implementation group vs 143 in the pre-implementation group). Solid organ cancer was present in 77/295 patients while immunomodulatory treatments were noticed in 135/295. They were 35 ICU-AI in 29/143 patients in the standard-care group as compared with 10 ICU-AI in 9/151 patients in the post-implementation group (p < 0.001). In a multivariable Poisson regression model, MSD was independently associated with a decreased incidence of ICU-AI (incidence rate ratio = 0.39; 95%CI [0.20-0.87] p = 0.008). There were 35/143 deaths in the standard-care group as compared with 22/151 in the post-implementation group (p = 0.046), this difference remained in a multivariable Cox model (HR = 0.58; 95CI [0.34-0.95] p = 0.048). CONCLUSION: In conclusion, MSD appeared to be associated with improved outcomes in critically ill immunocompromised patients.

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.

Characteristics and Prognosis Factors of Pneumocystis jirovecii Pneumonia According to Underlying Disease: A Retrospective Multicenter Study.

BACKGROUND: Pneumocystis jirovecii pneumonia (PcP) remains associated with high rates of mortality, and the impact of immunocompromising underlying disease on the clinical presentation, severity, and mortality of PcP has not been adequately evaluated. RESEARCH QUESTION: Does the underlying disease and immunosuppression causing PcP impact the outcome and clinical presentation of the disease? STUDY DESIGN AND METHODS: In this multicenter retrospective observational study, conducted from January 2011 to December 2021, all consecutive patients admitted with a proven or probable diagnosis of PcP according to the European Organisation for Research and Treatment of Cancer consensus definitions were included to assess the epidemiology and impact of underlying immunosuppressive diseases on overall and 90-day mortality. RESULTS: Overall, 481 patients were included in the study; 180 (37.4%) were defined as proven PcP and 301 (62.6%) were defined as probable PcP. Patients with immune-mediated inflammatory diseases (IMIDs) or solid tumors had a statistically poorer prognosis than other patients with PcP at day 90. In multivariate analysis, among the HIV-negative population, solid tumor underlying disease (OR, 5.47; 95% CI, 2.16-14.1; P < .001), IMIDs (OR, 2.19; 95% CI, 1.05-4.60; P = .037), long-term corticosteroid exposure (OR, 2.07; 95% CI, 1.03-4.31; P = .045), cysts in sputum/BAL smears (OR, 1.92; 95% CI, 1.02-3.62; P = .043), and SOFA score at admission (OR, 1.58; 95% CI, 1.39-1.82; P < .001) were independently associated with 90-day mortality. Prior corticotherapy was the only immunosuppressant associated with 90-day mortality (OR, 1.67; 95% CI, 1.03-2.71; P = .035), especially for a prednisone daily dose ≥ 10 mg (OR, 1.80; 95% CI, 1.14-2.85; P = .010). INTERPRETATION: Among patients who were HIV-negative, long-term corticosteroid prior to PcP diagnosis was independently associated with increased 90-day mortality, specifically in patients with IMIDs. These results highlight both the needs for PcP prophylaxis in patients with IMIDs and to early consider PcP curative treatment in severe pneumonia among patients with IMIDs.

Prevention of acquired invasive fungal infection with decontamination regimen in mechanically ventilated ICU patients: a pre/post observational study.

BACKGROUND: Invasive fungal infections acquired in the intensive care unit (AFI) are life-threating complications of critical illness. However, there is no consensus on antifungal prophylaxis in this setting. Multiple site decontamination is a well-studied prophylaxis against bacterial and fungal infections. Data on the effect of decontamination regimens on AFI are lacking. We hypothesised that multiple site decontamination could decrease the rate of AFI in mechanically ventilated patients. METHODS: We conducted a pre/post observational study in 2 ICUs, on adult patients who required mechanical ventilation for >24 h. During the study period, multiple-site decontamination was added to standard of care. It consists of amphotericin B four times daily in the oropharynx and the gastric tube along with topical antibiotics, chlorhexidine body wash and nasal mupirocin. RESULTS: In 870 patients, there were 27 AFI in 26 patients. Aspergillosis accounted for 20/143 of ventilator-associated pneumonia and candidemia for 7/75 of ICU-acquired bloodstream infections. There were 3/308 (1%) patients with AFI in the decontamination group and 23/562 (4%) in the standard-care group (p = 0.011). In a propensity-score matched analysis, there were 3/308 (1%) and 16/308 (5%) AFI in the decontamination group and the standard-care group respectively (p = 0.004) (3/308 vs 11/308 ventilator-associated pulmonary aspergillosis, respectively [p = 0.055] and 0/308 vs 6/308 candidemia, respectively [p = 0.037]). CONCLUSION: Acquired fungal infection is a rare event, but accounts for a large proportion of ICU-acquired infections. Our study showed a preventive effect of decontamination against acquired fungal infection, especially candidemia.Take home messageAcquired fungal infection (AFI) incidence is close to 4% in mechanically ventilated patients without antifungal prophylaxis (3% for pulmonary aspergillosis and 1% for candidemia).Aspergillosis accounts for 14% of ventilator-associated pneumonia and candidemia for 9% of acquired bloodstream infections.Immunocompromised patients, those infected with SARS-COV 2 or influenza virus, males and patients admitted during the fall season are at higher risk of AFI.Mechanically ventilated patients receiving multiple site decontamination (MSD) have a lower risk of AFI.

Prediction of pulmonary aspergillosis in patients with ventilator-associated pneumonia.

BACKGROUND: Predictors of ICU-acquired pulmonary aspergillosis (IPA) are not well-established in critically ill patients with ventilator-associated pneumonia (VAP), making IPA commonly misdiagnosed and anti-fungal therapy delayed. We aimed to develop a clinical score for prediction of IPA among patients with VAP. METHODS: Mechanically ventilated patients who developed VAP in 4 ICUs in Bretagne, Western France, were included. The score was constructed in a learning cohort, based on predictors of IPA in logistic regression model, and validated in a validation cohort. RESULTS: Among 1636 mechanically ventilated patients, 215 developed VAP but only 39 developed IPA (4 possible and 35 probable/putative) (18%). Most cases (31/39) were documented through a positive broncho-alveolar sample culture. Independent predictors of IPA were immunodepression (including onco-hematological disorder, immunomodulatory treatment, solid organ transplant, neutropenia < 0.5G/L and high-dose steroids ≥ 1 mg/kg/day of prednisolone equivalent) (p = 0.001; score = 1 point) and lymphocyte count at admission < 0.8 G/L (p = 0.019; score = 1 point). Operational values of the predictive score in the learning/validation cohort were 50%/52% sensitivity and 90%/87% specificity, respectively, for high PiPa score (score = 2) and 94%/91% sensitivity and 44%/46% specificity, respectively, for moderate PiPa score (score = 1). Finally, the AUC for the prediction of IPA was 0.783 in the learning cohort and 0.770 in the validation cohort. CONCLUSIONS: We evaluated a clinical score with good predictive value which may help to predict IPA in patient with VAP. External validation will be needed to confirm our preliminary findings.

The thermolysin-like metalloproteinase and virulence factor LasB from pathogenic Pseudomonas aeruginosa induces anoikis of human vascular cells.

Disruption of cell/ECM interactions resulting from uncontrolled pericellular proteolysis leads to detachment-induced cell apoptosis (anoikis), contributing to the morbid evolution of inflammatory vascular diseases. During cardiovascular infections, bacterial proteinases might induce vascular cells to enter a similar pathway. We focused on LasB, the predominant metalloproteinase secreted by the haematotropic pathogen Pseudomonas aeruginosa. While the exosecretome of the LasB-deficient pseudomonal strain PAO1lasBΔ had limited impact on human vascular cell adherence and viability, secretomes from the LasB-expressing reference strain, PAO1, or clinical isolates from patients with cardiac infection all induced anoikis, as did purified LasB. Immunofluorescence and/or immunoblotting analysis of heart valve myofibroblast cultures or whole tissue revealed an extensive, LasB-dependent degradation of ECM-associated fibronectin and vitronectin, that preceded cell de-adherence, whereas type I collagen showed limited degradation. Moreover, LasB produced a rapid endoproteolysis of the cell-associated urokinase receptor/uPAR, leaving a truncated receptor that is unable to support cell adherence and survival via interactions with vitronectin and integrins. Conversely, major myofibroblast integrins showed no or only minor alterations. Thus, among P. aeruginosa-secreted metalloproteinases, LasB can induce vascular cell anoikis through simultaneous proteolysis of ECM components and cell receptors, suggesting the uPAR-vitronectin axis as a major target in this process.

Deep brain stimulation hardware-related infections: a report of 12 cases and review of the literature.

In this monocentric study, the median delay between deep brain stimulation implantation and infection was 28 days (range, 8-820). Infections limited to generator (n = 4) required partial hardware removal, whereas infections involving frontal or retroauricular sites (n = 7) required total removal. Surgical samples yielded Staphylococcus aureus (n = 6), Staphylococcus epidermidis (n = 2), Propionibacterium acnes, and Micrococcus species.

Cyclomodulins in urosepsis strains of Escherichia coli.

Determinants of urosepsis in Escherichia coli remain incompletely defined. Cyclomodulins (CMs) are a growing functional family of toxins that hijack the eukaryotic cell cycle. Four cyclomodulin types are actually known in E. coli: cytotoxic necrotizing factors (CNFs), cycle-inhibiting factor (Cif), cytolethal distending toxins (CDTs), and the pks-encoded toxin. In the present study, the distribution of CM-encoding genes and the functionality of these toxins were investigated in 197 E. coli strains isolated from patients with community-acquired urosepsis (n = 146) and from uninfected subjects (n = 51). This distribution was analyzed in relation to the phylogenetic background, clinical origin, and antibiotic resistance of the strains. It emerged from this study that strains harboring the pks island and the cnf1 gene (i) were strongly associated with the B2 phylogroup (P, <0.001), (ii) frequently harbored both toxin-encoded genes in phylogroup B2 (33%), and (iii) were predictive of a urosepsis origin (P, <0.001 to 0.005). However, the prevalences of the pks island among phylogroup B2 strains, in contrast to those of the cnf1 gene, were not significantly different between fecal and urosepsis groups, suggesting that the pks island is more important for the colonization process and the cnf1 gene for virulence. pks- or cnf1-harboring strains were significantly associated with susceptibility to antibiotics (amoxicillin, cotrimoxazole, and quinolones [P, <0.001 to 0.043]). Otherwise, only 6% and 1% of all strains harbored the cdtB and cif genes, respectively, with no particular distribution by phylogenetic background, antimicrobial susceptibility, or clinical origin.

Performance of chromID ESBL, a chromogenic medium for detection of Enterobacteriaceae producing extended-spectrum beta-lactamases.

The chromogenic agar medium chromID ESBL (bioMérieux) was compared with BLSE agar medium (AES) for selective isolation and presumptive identification of extended-spectrum beta-lactamase (ESBL)-producing Enterobacteriaceae from clinical samples. A total of 765 samples (468 rectal swabs, 255 urine samples and 42 pulmonary aspirations) obtained from 547 patients was processed. All bacterial strains isolated on either medium were further characterized using biochemical tests, and ESBL producers were confirmed by synergy testing. Genetic characterization of ESBL genes was determined by PCR. A total of 33 ESBL-producing Enterobacteriaceae strains [Escherichia coli (n=16), Klebsiella pneumoniae (n=8), Enterobacter spp. (n=3), Citrobacter spp. (n=5) and Proteus mirabilis (n=1)] was recovered. The sensitivity after 24 h incubation was 88 % for chromID ESBL and 85 % for BLSE agar. At 48 h, the sensitivity of chromID ESBL increased to 94 % and was higher than that obtained with BLSE agar. The positive predictive value at 24 h for chromID ESBL was 38.7 % [95 % confidence interval (95 % CI) 28.3 -50.2 %)], which was significantly higher than that for BLSE agar [15.4 %, 95 % CI 10.1 -21.5 %]. On both media, false-positive results were mostly due to Pseudomonas aeruginosa and to Enterobacteriaceae overproducing chromosomal cephalosporinase (Enterobacter spp.) or a chromosomal penicillinase (Klebsiella oxytoca). This study showed that chromID ESBL, a ready-to-use chromogenic selective medium, is sensitive and specific for rapid, presumptive identification of ESBL-producing Enterobacteriaceae. Its chromogenic properties and its selectivity are particularly useful in specimens containing resident associated flora.

Emergence of Nontuberculous Mycobacterial Lymphadenitis in Children After the Discontinuation of Mandatory Bacillus Calmette and GuÉrin Immunization in France.

Eighty-five children were diagnosed with culture-confirmed nontuberculous mycobacterial cervical lymphadenitis within the MYCOMED surveillance network from 2004 to 2013. The mean incidence sharply increased from 0.57 to 3.7 per 100,000 children per year, after the discontinuation of mandatory bacillus Calmette and Guérin immunization in 2007. Cases were documented as Mycobacterium avium (62.3%), Mycobacterium intracellulare (15.3%) and Mycobacterium lentiflavum (12.9%). Outcome was favorable in all, with or without surgery or antimycobacterial treatment.

Imipenem-resistant Pseudomonas aeruginosa gastrointestinal carriage among hospitalized patients: risk factors and resistance mechanisms.

Risk factors for imipenem (IMP)-resistant Pseudomonas aeruginosa (IRPA) digestive carriage were analyzed, and genetic events contributing to select resistant isolates in patients exposed to IMP were investigated. Among the 150 patients with hospital-acquired P. aeruginosa digestive carriage, 38 isolates were IRPA. DNA pulsotypes revealed 16 distinct clones. In 4 patients, a second P. aeruginosa isolate showed resistance to IMP compared with the initial susceptible isolate. By comparing the different oprD sequences between IMP-susceptible P. aeruginosa and IRPA strains, a genetic event was systematically found for each resistant isolate, leading to either the absence of OprD or a truncated porin. The multivariate analysis demonstrated that prior IMP exposure was associated with IRPA carriage. In summary, we confirmed that IMP use selects for IRPA in the gut flora. Cross-transmission, however, was frequently observed in intensive care units. Combining epidemiologic approach and molecular analysis is a powerful tool to delineate mechanisms of emerging resistance.

Should we systematically perform central nervous system imaging in patients with Whipple's endocarditis?

BACKGROUND: Whipple's endocarditis is an uncommon disease, with approximately 100 cases reported to date. Case series suggest that Whipple's endocarditis usually presents without extracardiac manifestations of Whipple's disease. METHODS: We report 4 consecutive cases of Whipple's endocarditis associated with brain lesions. All patients fulfilled Duke Criteria for definite endocarditis. Whipple's disease was diagnosed through 16S rRNA polymerase chain reaction assays on valves excised from patients with culture-negative endocarditis (n=3) or through polymerase chain reaction and periodic acid staining-positive foamy macrophages on duodenal biopsy (n=1). RESULTS: All patients were male, aged 56 to 72 years. They presented with mitral (n=1), aortic (n=1), mitral and aortic (n=1), and tricuspid (n=1) endocarditis. Brain magnetic resonance imaging was performed because of mild-to-moderate cognitive disorders (n=3) or ataxia (n=1) and revealed multiple (n=3) or solitary (n=1) contrast-enhancing lesions. Cerebrospinal fluid studies revealed meningitis in 1 case. Polymerase chain reaction assays on cerebrospinal fluid were negative for all patients. All patients received intravenous ceftriaxone (2-4 weeks) associated with gentamicin (2 weeks), followed by 1 year of oral trimethoprim-sulfamethoxazole, with favorable outcomes. CONCLUSION: Whipple's associated central nervous system disease may be common but frequently undiagnosed, in patients with Whipple's endocarditis. Because treatment is different when neurologic disease is present (ie, trimethoprim-sulfamethoxazole vs doxycycline/hydroxychloroquine), clinicians should consider brain imaging in patients diagnosed with Whipple's endocarditis.