Influenza-associated invasive aspergillosis in patients admitted to the intensive care unit in Sweden: a prospective multicentre cohort study.

BACKGROUND: The purpose of this study was to prospectively investigate the incidence of influenza-associated pulmonary aspergillosis (IAPA) in influenza patients admitted to intensive care units in Sweden. METHODS: The study included consecutive adult patients with PCR-verified influenza A or B in 12 Swedish intensive care units (ICUs) over four influenza seasons (2019-2023). Patients were screened using serum galactomannan and ß-d-glucan tests and fungal culture of a respiratory sample at inclusion and weekly during the ICU stay. Bronchoalveolar lavage was performed if clinically feasible. IAPA was classified according to recently proposed case definitions. RESULTS: The cohort included 55 patients; 42% were female, and the median age was 59 (IQR 48-71) years. All patients had at least one galactomannan test, ß-d-glucan test and respiratory culture performed. Bronchoalveolar lavage was performed in 24 (44%) of the patients. Five (9%, 95% CI 3.8% - 20.4%) patients were classified as probable IAPA, of which four lacked classical risk factors. The overall ICU mortality was significantly higher among IAPA patients than non-IAPA patients (60% vs 8%, p = 0.01). CONCLUSIONS: The study represents the first prospective investigation of IAPA incidence. The 9% incidence of IAPA confirms the increased risk of invasive pulmonary aspergillosis among influenza patients admitted to the ICU. Therefore, it appears reasonable to implement a screening protocol for the early diagnosis and treatment of IAPA in influenza patients receiving intensive care. TRIAL REGISTRATION: ClinicalTrials.gov NCT04172610, registered November 21, 2019.

Early prediction of blood stream infection in a prospectively collected cohort.

BACKGROUND: Blood stream infection (BSI) and sepsis are serious clinical conditions and identification of the disease-causing pathogen is important for patient management. The RISE (Rapid Identification of SEpsis) study was carried out to collect a cohort allowing high-quality studies on different aspects of BSI and sepsis. The aim of this study was to identify patients at high risk for BSI who might benefit most from new, faster, etiological testing using neutrophil to lymphocyte count ratio (NLCR) and Shapiro score. METHODS: Adult patients (≥ 18 years) presenting at the emergency department (ED) with suspected BSI were prospectively included between 2014 and 2016 at Örebro University Hospital. Besides extra blood sampling, all study patients were treated according to ED routines. Electronic patient charts were retrospectively reviewed. A modified Shapiro score (MSS) and NLCR were extracted and compiled. Continuous score variables were analysed with area under receiver operator characteristics curves (AUC) to evaluate the ability of BSI prediction. RESULTS: The final cohort consisted of 484 patients where 84 (17%) had positive blood culture judged clinically significant. At optimal cut-offs, MSS (≥3 points) and NLCR (> 12) showed equal ability to predict BSI in the whole cohort (AUC 0.71/0.74; sensitivity 69%/67%; specificity 64%/68% respectively) and in a subgroup of 155 patients fulfilling Sepsis-3 criteria (AUC 0.71/0.66; sensitivity 81%/65%; specificity 46%/57% respectively). In BSI cases only predicted by NLCR> 12 the abundance of Gram-negative to Gram-positive pathogens (n = 13 to n = 4) differed significantly from those only predicted by MSS ≥3 p (n = 7 to n = 12 respectively) (p < 0.05). CONCLUSIONS: MSS and NLCR predicted BSI in the RISE cohort with similar cut-offs as shown in previous studies. Combining the MSS and NLCR did not increase the predictive performance. Differences in BSI prediction between MSS and NLCR regarding etiology need further evaluation.

Antibiotic treatment with one single dose of gentamicin at admittance in addition to a ß-lactam antibiotic in the treatment of community-acquired bloodstream infection with sepsis.

BACKGROUND: Combination therapy in the treatment of sepsis, especially the value of combining a ß-Lactam antibiotic with an aminoglycoside, has been discussed. This retrospective cohort study including patients with sepsis or septic shock aimed to investigate whether one single dose of gentamicin at admittance (SGA) added to ß-Lactam antibiotic could result in a lower risk of mortality than ß-Lactam monotherapy, without exposing the patient to the risk of nephrotoxicity. METHODS AND FINDINGS: All patients with positive blood cultures were evaluated for participation (n = 1318). After retrospective medical chart review, a group of patients with community-acquired sepsis with positive blood cultures who received ß-Lactam antibiotic with or without the addition of SGA (n = 399) were included for the analysis. Mean age was 74.6 yrs. (range 19-98) with 216 (54%) males. Sequential Organ Failure Assessment score (SOFA score) median was 3 (interquartile range [IQR] 2-5) and the median Charlson Comorbidity Index for the whole group was 2 (IQR 1-3). Sixty-seven (67) patients (17%) had septic shock. The 28-day mortality in the combination therapy group was 10% (20 of 197) and in the monotherapy group 22% (45 of 202), adjusted HR 3.5 (95% CI (1.9-6.2), p = < 0.001. No significant difference in incidence of acute kidney injury (AKI) was detected. CONCLUSION: This retrospective observational study including patients with community-acquired sepsis or septic shock and positive blood cultures, who meet Sepsis-3 criteria, shows that the addition of one single dose of gentamicin to ß-lactam treatment at admittance was associated with a decreased risk of mortality and was not associated with AKI. This antibiotic regime may be an alternative to broad-spectrum antibiotic treatment of community-acquired sepsis. Further prospective studies are warranted to confirm these results.

Dynamics of monocytic HLA-DR expression differs between bacterial etiologies during the course of bloodstream infection.

OBJECTIVE: In the pathogenesis of sepsis, activation of both pro- and anti-inflammatory responses are key components, but knowledge is lacking on the association between bacterial etiology and development of dysregulated responses with sustained immunosuppression. The aim of this study was to evaluate how the immunosupression marker HLA-DR on monocytes (mHLA-DR) is associated with bacterial etiology and markers of inflammation during the clinical trajectory of bloodstream infection (BSI). METHODS: Ninety-one adults, predominantly non-ICU patients, with BSI caused by Streptococcus pneumoniae (n = 27), Staphylococcus aureus (n = 22), Escherichia coli/Klebsiella pneumoniae (n = 23), and other species (n = 19) were prospectively included, and sampled on admission (day 0) and on days 1-2, 3, 7±1, 14±2, and 28±4. RESULTS: The dynamics of mHLA-DR, measured by flow cytometry, differed significantly between etiology groups (p<0.001). Patients with S. pneumoniae and S. aureus BSI demonstrated low initial mHLA-DR, with the S. aureus group showing delayed recovery over time. Eleven patients (55% S. aureus) had negative outcome (secondary bacteremia or death) and they demonstrated sustained C-reactive protein elevation, neutrophilia, lymphocytopenia, and loss of mHLA-DR. CONCLUSIONS: Dynamics of mHLA-DR varied according to the bacterial etiology of infection, with delayed recovery in patients with S. aureus BSI. Patients with negative outcome showed sustained CRP elevation, neutrophilia, lymphocytopenia, and low levels of mHLA-DR, supporting the theory of a dysregulated host response with persistent inflammation and immunosuppression in late stages of deleterious sepsis.

Prosthetic valve endocarditis caused by Propionibacterium species: a national registry-based study of 51 Swedish cases.

Propionibacterium spp. are a rare cause of infective endocarditis (IE). The diagnosis is difficult because the bacteria are slow-growing and growth in blood cultures is often misinterpreted as contamination from the skin flora. The aim of this study was to describe all cases of Propionibacterium spp. endocarditis in the Swedish national registry of IE. The registry was searched for all cases of IE from 1995 to 2016 caused by Propionibacterium spp. Data concerning clinical characteristics, treatment, and outcome were registered. A total of 51 episodes of definitive prosthetic valve endocarditis (PVE) caused by Propionibacterium spp. were identified, comprising 8% of cases of PVE during the study period. Almost all cases (n = 50) were male. The median time from surgery to diagnosis of IE was 3 years. Most patients were treated mainly with beta-lactams, partly in combination with aminoglycosides. Benzyl-penicillin was the most frequently used beta-lactam. A total of 32 patients (63%) underwent surgery. Overall, 47 patients (92.1%) were cured, 3 (5.9%) suffered relapse, and 1 (2.0%) died during treatment. IE caused by Propionibacterium spp. almost exclusively affects men with a prosthetic valve and findings of Propionibacterium spp. in blood cultures in such patients favors suspicion of a possible diagnosis of IE. In patients with prosthetic valves, prolonged incubation of blood cultures up to 14 days is recommended. The prognosis was favorable, although a majority of patients required cardiac surgery during treatment. Benzyl-penicillin should be the first-line antibiotic treatment option for IE caused by Propionibacterium spp.

Expression of HLA-DRA and CD74 mRNA in whole blood during the course of complicated and uncomplicated Staphylococcus aureus bacteremia.

To improve management of Staphylococcus aureus bacteremia (SAB), better understanding of host-pathogen interactions is needed. In vitro studies have shown that S. aureus bacteria induce dose-dependent immunosuppression that is evidenced by reduced expression of major histocompatibility complex (MHC) class II on antigen presenting cells. Thus, the aim of this study was to determine whether expression of the MHC class II-related genes HLA-DRA and CD74 is more greatly reduced in complicated SAB, with its probable higher loads of S. aureus, than in uncomplicated SAB. Adult patients with SAB were prospectively included and blood samples taken on the day of confirmation of SAB (Day 1) and on Days 2, 3, 5 and 7. HLA-DRA and CD74 mRNA expression was determined by quantitative reverse transcription PCR. Sepsis was defined according to the Sepsis-3 classification and SAB was categorized as complicated in patients with deep-seated infection and/or hematogenous seeding. Twenty patients with SAB were enrolled and samples obtained on all assessment days. HLA-DRA and CD74 expression did not differ significantly between patients with SAB and sepsis (n = 13) and those without sepsis (n = 7) on any assessment day. However, patients with complicated SAB (n = 14) had significantly weaker HLA-DRA expression on all five assessment days than patients with uncomplicated SAB (n = 6). Additionally, they tended to have weaker CD74 expressions. Neutrophil, monocyte and leukocyte counts did not differ significantly between complicated and uncomplicated SAB. In conclusion, patients with complicated SAB show weaker HLA-DRA expression than those with uncomplicated SAB during the first week of bacteremia.

Quantitative Real-Time Polymerase Chain Reaction Measurement of HLA-DRA Gene Expression in Whole Blood Is Highly Reproducible and Shows Changes That Reflect Dynamic Shifts in Monocyte Surface HLA-DR Expression during the Course of Sepsis.

INTRODUCTION: A decrease in the expression of monocyte surface protein HLA-DR (mHLA-DR), measured by flow cytometry (FCM), has been suggested as a marker of immunosuppression and negative outcome in severe sepsis. However, FCM is not always available due to sample preparation that limits its use to laboratory operational hours. In this prospective study we evaluated dynamic changes in mHLA-DR expression during sepsis in relation to changes in HLA-DRA gene expression and Class II transactivator (CIITA), measured by quantitative Real-Time Polymerase Chain Reaction (qRT-PCR). AIMS: The aims of this study were: 1. to validate the robustness of qRT-PCR measurement of HLA-DRA- and CIITA-mRNA expression, in terms of reproducibility; and 2. to see if changes in expression of these genes reflect changes in mHLA-DR expression during the course of severe and non-severe bacteraemic sepsis. METHODS AND FINDINGS: Blood samples were collected from 60 patients with bacteraemic sepsis on up to five occasions during Days 1-28 after hospital admission. We found the reproducibility of the qRT-PCR method to be high by demonstrating low threshold variations (<0.11 standard deviation (SD)) of the qRT-PCR system, low intra-assay variation of Ct-values within triplicates (≤0.15 SD) and low inter-assay variations (12%) of the calculated target gene ratios. Our results also revealed dynamic HLA-DRA expression patterns during the course of sepsis that reflected those of mHLA-DR measured by FCM. Furthermore, HLA-DRA and mHLA-DR recovery slopes in patients with non-severe sepsis differed from those in patients with severe sepsis, shown by mixed model for repeated measurements (p<0.05). However, during the first seven days of sepsis, PCR-measurements showed a higher magnitude of difference between the two sepsis groups. Mean differences (95% CI) between severe sepsis (n = 20) and non-severe sepsis (n = 40) were; on day 1-2, HLA-DRA 0.40 (0.28-0.59) p<0.001, CIITA 0.48 (0.32-0.72) p = 0.005, mHLA-DR 0.63 (0.45-1.00) p = 0.04, day 7 HLA-DRA 0.59 (0.46-0.77) p<0.001, CIITA 0.56 (0.41-0.76) p<0.001, mHLA-DR 0.81 (0.66-1.00) p = 0.28. CONCLUSION: We conclude that qRT-PCR measurement of HLA-DRA expression is robust, and that this method appears to be preferable to FCM in identifying patients with severe sepsis that may benefit from immunostimulation.

An angry cat causing Pasteurella multocida endocarditis and aortic valve replacement-A case report.

INTRODUCTION: Cat bite infections usually involve a mix of anaerobic and aerobic bacteria including species of Pasteurella, Streptococcus, Staphylococcus, Bacteroides, and Fusobacterium. We report a case of Pasteurella multocida infection from cat bites leading to endocarditis and subsequent aortic valve replacement. PRESENTATION OF CASE: A 70-year-old male was admitted because of fever, tachycardia, and malaise. He had a history of alcohol abuse and was living alone with a cat in a rural area. A sepsis of unknown origin was suspected, and intravenous treatment with gentamicin and cefotaxime was initiated. Blood cultures yielded Pasteurella multocida, and the patient history revealed repeated cat bites. After four days, the patient was discharged with oral penicillin V treatment. Two weeks later, the patient returned with fever and a new systolic murmur. An aortic valve endocarditis was diagnosed, and it became clear that the patient had not completed the prescribed penicillin V treatment. The patient underwent a biological aortic valve replacement with debridement of an annular abscess, and the postoperative course was uneventful. DISCUSSION: Endocarditis due to Pasteurella is extremely rare, and there are only a few reports in the literature. Predisposing factors in the present case were alcohol abuse and reduced compliance to treatment. CONCLUSION: Cat bites are often deep, and in rare circumstances can lead to life-threatening endocarditis. Proper surgical revision, antibiotic treatment, and patient compliance are necessary components in patient care to avoid this complication.

Preliminary results in quantitation of HLA-DRA by real-time PCR: a promising approach to identify immunosuppression in sepsis.

INTRODUCTION: Reduced monocyte human leukocyte antigen (mHLA)-DR surface expression in the late phase of sepsis is postulated as a general biomarker of sepsis-induced immunosuppression and an independent predictor of nosocomial infections. METHODS: Fifty-nine patients with sepsis and blood culture growing pathogenic bacteria were studied. Blood samples were collected at day 1 or 2 after admission, for measurement of mHLA-DR by flow cytometry and mRNA expression of HLA-DRA and class II transactivator (CIITA) by qRT-PCR. Blood samples from blood donors were used as controls (n = 30). RESULTS: A significant reduced expression of mHLA-DR, HLA-DRA, and CIITA was seen in septic patients compared with controls. HLA-DRA mRNA level in whole blood was highly correlated with surface expression of mHLA-DR. CONCLUSIONS: Patients with sepsis display a diminished expression of HLA-DR at the monocyte surface as well as in the gene expression at the mRNA level. The mRNA expression level of HLA-DRA monitored by qRT-PCR correlates highly with surface expression of HLA-DR and appears to be a possible future biomarker for evaluation of immunosuppression in sepsis.

Collagen-gentamicin implant for prevention of sternal wound infection; long-term follow-up of effectiveness.

In a previous randomized controlled trial (LOGIP trial) the addition of local collagen-gentamicin reduced the incidence of postoperative sternal wound infections (SWI) compared with intravenous prophylaxis only. Consequently, the technique with local gentamicin was introduced in clinical routine at the two participating centers. The aim of the present study was to re-evaluate the technique regarding the prophylactic effect against SWI and to detect potential shifts in causative microbiological agents over time. All patients in this prospective two-center study received prophylaxis with application of two collagen-gentamicin sponges between the sternal halves in addition to routine intravenous antibiotics. All patients were followed for 60 days postoperatively. From January 2007 to May 2008, 1359 patients were included. The 60-day incidences of any SWI was 3.7% and of deep SWI 1.5% (1.0% mediastinitis). Both superficial and deep SWI were significantly reduced compared with the previous control group (OR=0.34 for deep SWI, P<0.001). There was no increase in the absolute incidence of aminoglycoside resistant agents. The majority of SWI were caused by coagulase-negative staphylococci (CoNS). The incidence of deep SWI caused by Staphylococcus aureus was 0.07%. The results indicate a maintained effect of the prophylaxis over time without absolute increase in aminoglycoside resistance. (ClinicalTrials.gov NCT00484055).

Antibiotic prophylaxis in cardiac surgery--general principles.

Appropriate antibiotic prophylaxis in cardiac surgery can substantially reduce the number of postoperative infections. To avoid misuse, special concerns - such as timing and duration of antibiotics - must be taken into account. Increasing evidence supports that 24 h antibiotic prophylaxis is sufficient for most major surgical procedures. The prophylactic antibiotic should cover the spectrum of bacteria that are likely to be encountered. The emergence of MRSA raises special questions of antibiotic choice as well as route of administration.

Genetic homogeneity/heterogeneity of Propionibacterium acnes isolated from patients during cardiothoracic reoperation.

Following cardiothoracic surgery, deep sternal wound infection (SWI) remains one of the most severe complications. Recently, Propionibacterium acnes has been suspected as an etiological agent of deep SWI. However, this bacterium constitutes part of the resident micro-flora of the human skin. Consequently, findings of P. acnes in invasive samples are difficult to value. The aims of this study were to develop and optimize a pulsed-field gel electrophoresis (PFGE) protocol for P. acnes, in order to investigate the genetic homogeneity/heterogeneity of P. acnes isolates from multiple tissue samples (predominantly biopsies), collected at different locations, from 12 patients during cardiothoracic reoperation. There were 24 distinguishable PFGE fingerprints identified among the P. acnes isolates (n=54). Five (42%) of the patients carried only isolates that were interpreted as presumably clonally related. From the remaining seven patients, two or three different P. acnes clones were cultured, however, from six of them, the clones were identified in multiple samples. P. acnes may be a relatively frequent etiological agent of postoperative cardiothoracic infections. Existence of several clonally related P. acnes isolates derived from multiple samples from patients suffering from deep SWI after cardiothoracic surgery has not previously been shown.

Coagulase-negative staphylococci isolated from sternal wound infections after cardiac surgery: attachment to and accumulation on sternal fixation stainless steel wires.

Sternal wound infection (SWI) is a serious complication after cardiac surgery. Coagulase-negative staphylococci (CoNS) have been found to be the most common pathogen involved in this postoperative infection related to implanted foreign materials, i.e. sternal fixation wires made from stainless steel. In this study a rapid and simple assay was developed for studying attachment and accumulation of CoNS on stainless steel wires in vitro using [(3)H] thymidine. The method showed a potential to detect differences in the dynamics of the adherence patterns among various CoNS isolates. However, no differences in attachment and accumulation were found between isolates causing deep SWI after cardiac surgery and contaminant isolates. In addition, there were no differences in the distribution of the ica operon between the two groups, as determined by polymerase chain reaction (PCR). Nevertheless, the ability to produce biofilm was found to be present significantly more frequently among SWI isolates than among contaminants.

Cost effectiveness of local collagen-gentamicin as prophylaxis for sternal wound infections in different risk groups.

OBJECTIVES: In a randomized trial addition of local collagen-gentamicin in the sternal wound reduced the rate of sternal wound infection (SWI) to about 50% compared to intravenous prophylaxis alone. The aim of the present study was to evaluate the economic rationale for its use in every-day clinical practice. This includes the question whether high-risk groups that may have particular benefit should be identified. DESIGN: For each patient with SWI in the trial the costs attributable to the SWI were calculated. Risk factors for SWI were identified and any heterogeneity of the effect of the prophylaxis examined. RESULTS: The mean cost of a SWI was about 14500 Euros. A cost effectiveness analysis showed that the prophylaxis was cost saving. The positive net balance was even higher in risk groups. Assignment to the control group, overweight, diabetes, younger age, mammarian artery use, left ventricular ejection fraction <35% and longer operation time were independent risk factors for infection. CONCLUSION: The addition of local collagen-gentamicin to intravenous antibiotic prophylaxis was dominant, i.e. resulted in both lower costs and fewer wound infections.

The influence of adhesive and invasive properties of Staphylococcus aureus defective in fibronectin-binding proteins on secretion of interleukin-6 by human endothelial cells.

Fibronectin-binding proteins (FnBP) are surface adhesins of Staphylococcus aureus documented to be virulence attributes in, for example, endovascular infections. By using mutants of S. aureus defective in the FnBPA and B genes we have investigated whether these adhesins affect cytokine expression in human umbilical vein endothelial cells (HUVEC). S. aureus expressing FnBPA and B adhered to and were internalized into HUVEC to a greater extent compared to mutants defective in expression of FnBP. Production and release of IL-6 was higher from endothelial cells infected with the parent FnBP-expressing strain compared to the FnBP-defective mutants. These results indicate that adhesion to and invasion of S. aureus into endothelial cells are important regulators of cytokine expression.

Local gentamicin reduces sternal wound infections after cardiac surgery: a randomized controlled trial.

BACKGROUND: Sternal wound infections remain a major cause of morbidity after cardiac surgery. Vancomycin is often the only effective antibiotic available for their treatment but its use for routine prophylaxis is inadvisable for ecological reasons. Local application of gentamicin produces high antibiotic concentrations in the wound. We aimed to determine whether this treatment could have an additive effect on the incidence of sternal wound infections when combined with routine prophylaxis. METHODS: Two thousand cardiac surgery patients were randomized to routine prophylaxis with intravenous isoxazolyl-penicillin alone (control group) or to this prophylaxis combined with application of collagen-gentamicin (260 mg gentamicin) sponges within the sternotomy before wound closure. Endpoint was any sternal wound infection within 2 months postoperatively. Evaluations were double-blind and made on an intention-to-treat basis. RESULTS: Evaluation was possible in 967 and 983 patients in the control and treatment groups, respectively. The incidence of sternal wound infection was 4.3% in the treatment group and 9.0% in the control group (relative risk 0.47; 95% confidence interval 0.33-0.68; p < 0.001). Early reoperation for bleeding was more common in the treatment group (4.0% vs 2.3%, p = 0.03). No difference in postoperative renal function was noted. CONCLUSIONS: Local collagen-gentamicin reduced the risk for postoperative sternal wound infections. Further studies are warranted to confirm these results, particularly with regard to deep infections.

Antibiotic concentrations in serum and wound fluid after local gentamicin or intravenous dicloxacillin prophylaxis in cardiac surgery.

One important aim of antibiotic prophylaxis in cardiac surgery is preventing mediastinitis and thus it would appear to be relevant to study the antibiotic concentrations in pericardial/mediastinal fluid. Local administration of gentamicin in the wound before sternal closure is a novel way of antibiotic prophylaxis and could be effective against bacteria resistant to intravenous antibiotics. This study measured dicloxacillin concentrations in 101 patients in serum and wound fluid following intravenous administration of dicloxacillin. Similarly, concentrations of gentamicin in serum and wound fluid were determined in 30 patients after administration of 260 mg gentamicin in the wound at sternal closure. Median dicloxacillin concentrations in serum and wound fluid at sternal closure were 59.4 and 55.35 mg/l, respectively. Gentamicin levels in the wound were very high (median 304 mg/l), whereas serum concentrations were low (peak median 2.05 mg/l). Dicloxacillin, 1 g given intravenously, according to the clinical protocol, resulted in levels in serum and wound fluid at sternal closure likely to prevent Staphylococcus aureus infections. Locally administered gentamicin resulted in high local concentrations, potentially effective against agents normally considered resistant.