Robert Krause

Performance of Galactomannan, Beta-d-Glucan, Aspergillus Lateral-Flow Device, Conventional Culture, and PCR Tests with Bronchoalveolar Lavage Fluid for Diagnosis of Invasive Pulmonary Aspergillosis

ABSTRACT Galactomannan detection in bronchoalveolar lavage (BAL) fluid samples (GM test) is currently considered the gold standard test for diagnosing invasive pulmonary aspergillosis (IPA). The limitations, however, are the various turnaround times and availability of testing. We compared the performance of GM testing with that of conventional culture, an Aspergillus lateral-flow-device (LFD) test, a beta-d-glucan (BDG) test, and an Aspergillus PCR assay by using BAL fluid samples from immunocompromised patients. A total of 78 BAL fluid samples from 78 patients at risk for IPA (74 samples from Graz and 4 from Mannheim) collected between December 2012 and May 2013 at two university hospitals in Austria and Germany were included. Three patients had proven IPA, 14 probable IPA, and 17 possible IPA, and 44 patients had no IPA. The diagnostic accuracies of the different methods for probable/proven IPA were evaluated. The diagnostic odds ratios were the highest for the GM, PCR, and LFD tests. The sensitivities for the four methods (except culture) were between 70 and 88%. The combination of the GM (cutoff optical density index [ODI], >1.0) and LFD tests increased the sensitivity to 94%, while the combination of the GM test (>1.0) and PCR resulted in 100% sensitivity (specificity for probable/proven IPA, 95 to 98%). The performance of conventional culture was limited by low sensitivity, while that of the BDG test was limited by low specificity. We evaluated established and novel diagnostic methods for IPA and found that the Aspergillus PCR, LFD, and GM tests were the most useful methods for diagnosing the disease by using BAL fluid samples. In particular, the combination of the GM test and PCR or, if PCR is not available, the LFD test, allows for sensitive and specific diagnosis of IPA.

The Nationwide Austrian Aspergillus Registry: a prospective data collection on epidemiology, therapy and outcome of invasive mould infections in immunocompromised and/or immunosuppressed patients

A prospective, observational, multicentre study was performed to assess the incidence, diagnosis, epidemiology and outcome of invasive mould infections (IMIs) reported to the Nationwide Austrian Aspergillus Registry. In total, 186 cases were recorded, corresponding to an annual incidence of 42 cases/1000 patients at risk or 2.36 cases/100000 inhabitants. Patients with acute myelogenous leukaemia (34%) and lung transplant recipients (17%) are currently at highest risk for IMI, followed by a mixed population with impaired immunity (14%). In total, 34%, 30% and 36% were proven, probable and possible cases of IMI. Predominant pathogens were Aspergillus spp. (67%), followed by the zygomycetes (28%). Voriconazole was the most frequently administered agent (38%), followed by caspofungin (20%) and posaconazole (19%). Eighty patients (43%) received antifungal prophylaxis for ≥7 days, 30% of whom (24 patients) suffered from a breakthrough infection. The overall crude 12-week mortality was 34%. Multivariate analysis showed that outcome and survival did not correlate with the status of fungal disease, breakthrough infection, fungal species or age (P>0.05). Aspergillosis remains the most commonly identified IMI amongst immunocompromised and/or immunosuppressed patients, but other moulds constitute a significant problem. Survival from IMIs appears to have improved and the main challenge is to overcome breakthrough fungal infections.

Role of Candida in Antibiotic-Associated Diarrhea

To quantitatively assess the role of Candida species in antibiotic-associated diarrhea (AAD), stool samples from a total of 395 patients and control subjects were cultured in differential isolation medium: 98 patients had AAD, 93 patients were taking antibiotics but did not have diarrhea (A(+)D(-)), 97 patients were not taking antibiotics but had diarrhea (A(-)D(+)), and 107 patients were control subjects (A(-)D(-)). In addition, secreted aspartyl proteinase (Sap) production was tested. In AAD patients, Candida positivity (77/98) and Candida overgrowth (62/98) were not different from that among A(+)D(-) patients (75/93 [P= .860] and 52/93 [P= .375], respectively). Candida overgrowth among A(-)D(+) patients (40/97, P= .003) was less frequent than among AAD patients, but Candida positivity was not different (80/97, P= .612). In control subjects, Candida positivity and overgrowth were less common than in all other groups. Production of Sap did not differ between patients with AAD and control subjects (P= .568 and P= .590, respectively). Data indicate that elevated Candida counts are a result of antibiotic treatment or diarrhea rather than a cause of AAD.

Novel Tests for Diagnosis of Invasive Aspergillosis in Patients with Underlying Respiratory Diseases

RATIONALE Invasive pulmonary aspergillosis has been increasingly reported in nonneutropenic patients, including those with underlying respiratory diseases. OBJECTIVES We compared the diagnostic performances of galactomannan, 1,3-β-D-glucan, and Aspergillus-specific lateral-flow device tests with that of conventional culture by using bronchoalveolar lavage fluid samples from patients with underlying respiratory diseases. METHODS We analyzed 268 bronchoalveolar lavage samples from 221 patients with underlying respiratory diseases (and without hematologic malignancy or previous solid organ transplantation) that were collected for routine microbiological workup between February 2012 and May 2014 at the University Hospital of Graz, Austria. Invasive pulmonary aspergillosis was defined according to European Organization of Research and Treatment of Cancer/Mycoses Study Group criteria modified for patients with respiratory diseases. MEASUREMENTS AND MAIN RESULTS Thirty-one patients (14%) had probable or proven, 25 possible, and the remaining 165 patients no invasive pulmonary aspergillosis. Probable/proven aspergillosis was associated with a significantly higher (P = 0.034) 30-day mortality rate of 32%. Sensitivities, specificities, and diagnostic odd ratios differed markedly between galactomannan (cut-off 0.5: optical density index, 0.97, 0.81, 124.4; cut-off 1.0: 0.97, 0.93, 422.1; cut-off 3.0: 0.61, 0.99, 109.8), β-D-glucan (cut-off 80 pg/ml: 0.90, 0.42, 6.57; cut-off 200 pg/ml: 0.70, 0.61, 3.7), lateral-flow device tests (0.77, 0.92, 41.8), and mycological culture (0.29, 0.97, 14). CONCLUSIONS Probable or proven invasive pulmonary aspergillosis was diagnosed in 14% of our study population and associated with significantly higher 30-day mortality rates. Although the performance of β-D-glucan was limited by low specificity and that of mycological culture by low sensitivity, the Aspergillus lateral-flow device seems to be a promising alternative to galactomannan testing, which remains the diagnostic gold standard for aspergillosis. Clinical trial registered with www.clinicaltrials.gov (NCT 02058316).

Diagnosis, treatment, and prognosis of Mycoplasma pneumoniae childhood encephalitis: systematic review of 58 cases.

Most of the knowledge on Mycoplasma pneumoniae encephalitis in children is based on case reports or small case series. The aim of this study was to assess the important features of the disease by a systematic review of previously published cases. Overall, 58 cases (22 female, 36 male; median age 10 years, range: 2—17 years), derived from 38 reports, were reviewed. Forty-five patients (76%) had flulike or respiratory symptoms prior to the onset of neurologic disease, and 23 patients (40%) presented with pulmonary infiltrates. Cerebrospinal fluid (CSF) pleocytosis (mostly mononuclear cells) and elevated cerebrospinal fluid protein counts were present in 34 (59%) and 21 (36%) patients, respectively. Cranial computed tomography (CT) or magnetic resonance imaging (MRI) abnormalities were seen in 18 (31%) and 17 (29%) patients, respectively, whereby various different presentations were observed. Forty-four patients (76%) received antimicrobial therapy active against mycoplasmas, most frequently erythromycin (n = 29) or minocycline (n = 6). Only in one patient, cure was directly attributed to antimicrobial therapy (with chloramphenicol) by the respective authors. Thirty-three patients (57%) recovered without sequelae, 20 patients (34%) had minor to major sequelae, and 5 patients (9%) died. A high cerebrospinal fluid cell count, cerebrospinal fluid protein elevation, and higher age were associated with an unfavorable outcome. (J Child Neurol 2004;19:865—871).

Strategies to enhance rational use of antibiotics in hospital : a guideline by the German society for infectious diseases

IntroductionIn the time of increasing resistance and paucity of new drug development there is a growing need for strategies to enhance rational use of antibiotics in German and Austrian hospitals. An evidence-based guideline on recommendations for implementation of antibiotic stewardship (ABS) programmes was developed by the German Society for Infectious Diseases in association with the following societies, associations and institutions: German Society of Hospital Pharmacists, German Society for Hygiene and Microbiology, Paul Ehrlich Society for Chemotherapy, The Austrian Association of Hospital Pharmacists, Austrian Society for Infectious Diseases and Tropical Medicine, Austrian Society for Antimicrobial Chemotherapy, Robert Koch Institute.Materials and methodsA structured literature research was performed in the databases EMBASE, BIOSIS, MEDLINE and The Cochrane Library from January 2006 to November 2010 with an update to April 2012 (MEDLINE and The Cochrane Library). The grading of recommendations in relation to their evidence is according to the AWMF Guidance Manual and Rules for Guideline Development.ConclusionThe guideline provides the grounds for rational use of antibiotics in hospital to counteract antimicrobial resistance and to improve the quality of care of patients with infections by maximising clinical outcomes while minimising toxicity. Requirements for a successful implementation of ABS programmes as well as core and supplemental ABS strategies are outlined. The German version of the guideline was published by the German Association of the Scientific Medical Societies (AWMF) in December 2013.

Posaconazole plasma concentrations and invasive mould infections in patients with haematological malignancies

Posaconazole (PCZ) is a triazole antifungal agent that has broad activity against pathogenic fungi and is increasingly used for prophylaxis and treatment of invasive mould infections (IMIs). PCZ is only available as an oral formulation, with varying absorption from the gastrointestinal tract. However, reports correlating PCZ plasma concentrations (PPCs) with breakthrough IMIs are rare. In this study, PPCs were analysed in a prospective, observational, single-centre study and the correlation of PPCs with breakthrough IMIs in patients with haematological malignancies was evaluated. Risk factors associated with low PPCs were further evaluated. A total of 109 PPCs were measured in 34 cases receiving PCZ prophylaxis (n=31) or treatment (n=3). Levels below the target of 0.5 μg/mL were detected in 24 (71%) of the 34 cases; in 15 (63%) of these 24 cases concentrations were found to be <0.20 μg/mL. Three patients receiving PCZ prophylaxis met the criteria of breakthrough infection. Notably, prior to development of IMI, PPCs were below the target in all three individuals. Associated risk factors for insufficient PPCs varied from previous reports. In conclusion, these data demonstrate that therapeutic drug monitoring of PCZ is mandatory in all patients with haematological malignancies as low PPCs are common and may be associated with development of IMIs.

Diagnostic accuracy of soluble urokinase plasminogen activator receptor (suPAR) for prediction of bacteremia in patients with systemic inflammatory response syndrome.

OBJECTIVES Soluble urokinase plasminogen activator receptor (suPAR) serum concentrations have recently been described to reflect the severity status of systemic inflammation. In this study, the diagnostic accuracy of suPAR, C-reactive protein (CRP), procalcitonin (PCT), and interleukin-6 (IL-6) to predict bacteremia in patients with systemic inflammatory response syndrome (SIRS) was compared. METHODS A total of 132 patients with SIRS were included. In 55 patients blood cultures had resulted positive (study group 1, Gram positive bacteria: Staphylococcus aureus and Streptococcus spp., n=15; study group 2, Gram-negative bacteria, n=40) and 77 patients had negative blood culture results (control group, n=77). Simultaneously with blood cultures suPAR, CRP, PCT, IL-6 and white blood count (WBC) were determined. RESULTS SuPAR values were significantly higher in study group 1 (median 8.11; IQR 5.78-15.53; p=0.006) and study group 2 (median 9.62; IQR 6.52-11.74; p<0.001) when compared with the control group (median 5.65; IQR 4.30-7.83). ROC curve analysis revealed an AUC of 0.726 for suPAR in differentiating SIRS patients with bacteremia from those without. The biomarkers PCT and IL-6 showed comparable results. Regarding combinations of biomarkers multiplying suPAR, PCT and IL-6 was most promising and resulted in an AUC value of 0.804. Initial suPAR serum concentrations were significantly higher (p=0.028) in patients who died within 28 days than in those who survived. No significant difference was seen for PCT, IL-6 and CRP. CONCLUSION In conclusion, suPAR, IL-6 and PCT may contribute to predicting bacteremia in SIRS patients.

European Organization for the Research and Treatment of Cancer/Mycoses Study Group (EORTC/MSG) host factors and invasive fungal infections in patients with haematological malignancies

OBJECTIVES Fulfilment of host factors defined by the revised European Organization for the Research and Treatment of Cancer/Mycoses Study Group (EORTC/MSG) criteria is required for establishing the diagnosis of possible or probable invasive fungal infection (IFI). This case-control study evaluates EORTC/MSG host factors among patients with haematological malignancies. METHODS Fifty-eight patients with haematological malignancies who developed probable (n = 38) or proven (n = 20) IFI over a 5 year period were retrospectively evaluated regarding EORTC/MSG host factors. Results were compared with those obtained from patients with haematological malignancies who did not develop IFI (116 patients who received systemic antifungal prophylaxis or empirical therapy and 116 patients who did not; all data collected in 2010). RESULTS Fourteen patients had invasive yeast infection and 44 patients had invasive mould infection (IMI). Prolonged neutropenia (35/58, 60% versus 29/116, 25%), prolonged systemic corticosteroid (cut-off 21 days: 13/58, 22% versus 6/116, 5%; cut-off 14 days: 18/58, 31% versus 9/116, 8%) and T cell suppressive therapy (35/44, 80% versus 69/116, 59%) were significantly associated with development of IFI/IMI in our cohort. Previous allogeneic stem cell transplantation (SCT; >6 months prior to episode) was not significantly associated with development of IMI (8/44, 18% versus 22/116, 19%), while recent SCT (<6 months prior to episode) was (11/44, 25% versus 12/116, 10%). CONCLUSIONS We conclude that host factors according to revised EORTC/MSG criteria were significantly associated with the development of IFI/IMI in our patients. Previous allogeneic SCT was not a predisposing host factor for the development of IMI. Concerning prolonged corticosteroid treatment, a cut-off of 14 days seems preferable to the proposed cut-off.

Role of Klebsiella oxytoca in Antibiotic-Associated Diarrhea

BACKGROUND Klebsiella oxytoca was recently shown to be the causative agent of antibiotic-associated hemorrhagic colitis. Because it is unclear whether K. oxytoca also causes nonhemorrhagic antibiotic-associated diarrhea, our study investigated a possible association between K. oxytoca and that disorder. METHODS A total of 371 consecutive patients were recruited into 4 study groups: (1) group A+D+ (patients who received antibiotics and experienced diarrhea; n = 107), (2) group A+D- (patients who received antibiotics but did not experience diarrhea; np93), (3) group A-D+ (patients who experienced acute-onset diarrhea but did not receive antibiotics; n = 60), and (4) group A-D- (patients without diarrhea who did not receive antibiotics; n = 111). Stool samples were plated on MacConkey agar and K. oxytoca was identified using a standard test kit. Clostridium difficile was detected by a toxin A/B antigen test. K. oxytoca strains were tested for cytotoxicity with use of cell-culture assays. RESULTS In 15 of 371 stool samples, K. oxytoca strains were isolated during the study period. There was no significant difference in the distribution of K. oxytoca among the 4 study groups. Six of the 15 strains were found to be toxin producing. Three of the toxin-producing strains caused antibiotic-associated hemorrhagic colitis. No case of nonhemorrhagic antibiotic-associated diarrhea due to toxin-producing K. oxytoca was detected. CONCLUSION K. oxytoca is not the causative agent of nonhemorrhagic antibiotic-associated diarrhea. This is in contrast to the distinct clinical entity of antibiotic-associated hemorrhagic colitis. Testing for K. oxytoca is therefore only warranted for patients who experience bloody diarrhea during antibiotic therapy.