Performance of the AsperGenius® PCR assay for detecting azole resistant Aspergillus fumigatus in BAL fluids from allogeneic HSCT recipients: A prospective cohort study from Essen, West Germany.

In this study a commercially available multiplex real-time PCR (AsperGenius®) was evaluated for its efficacy in detecting Aspergillus fumigatus and azole resistance markers in comparison with conventional culture methods and galactomannan (GM) testing from BAL fluids in allogeneic HSCT recipients. Between January 2015 and May 2017 100 allogeneic HSCT recipients with pulmonary infiltrates and suspicion of invasive fungal infection were recruited to the study from a tertiary care center in Germany. BAL fluid was routinely assessed using the following diagnostic tests: AsperGenius® PCR assay, GM testing (cut-off: 1.0) and conventional culture. Susceptibility testing of azoles was performed by using Etest and, in case presenting elevated MICs, PCR for mutations in the cyp51A gene was carried out. Criteria of EORTC/MSG were used to classify the patients for invasive fungal disease. According to the EORTC/MSG criteria 23 patients presented with probable invasive aspergillosis (IA). Aspergillus PCR showed a sensitivity of 65% for probable IA cases. A combination of PCR and GM results in BAL displayed a sensitivity of 96% (22/23) and 100% specificity. Mutations in the cyp51A gene were detected by PCR in three cases (3/23; 13%) which were also found resistant with the culture method. In one case a Y121F/T289A mutation and in two cases a L98H were found. The combination of a commercial Aspergillus PCR assay and GM testing from BAL demonstrated a high sensitivity and specificity for diagnosing IA in allogeneic HSCT recipients. The Aspergillus PCR assay was not superior in detecting azole resistant A. fumigatus compared to culture.

Prevalence and characterization of azole-resistant Aspergillus fumigatus in patients with cystic fibrosis: a prospective multicentre study in Germany.

Objectives: Aspergillus fumigatus is the most prevalent filamentous fungus in the respiratory tract of patients with cystic fibrosis (CF). The aim of this prospective multicentre study was to investigate the prevalence of azole-resistant A. fumigatus (ARAF) in respiratory secretions from CF patients across Germany and to characterize ARAF isolates by phenotypic and molecular methods. Methods: Twelve tertiary care centres from Germany participated in the study. In total, 2888 A. fumigatus isolates from 961 CF patients were screened for ARAF by using azole-containing agar plates. Antifungal susceptibility testing of isolates was performed by broth microdilution according to EUCAST guidelines. Analysis of mutations mediating resistance was performed using PCR and sequencing of the cyp51A gene. Furthermore, genotyping by microsatellite PCR was performed. Results: Of a total of 2888 A. fumigatus isolates, 101 isolates from 51 CF patients were found to be azole resistant (prevalence per patient 5.3%). The Essen centre had the highest prevalence (9.1%) followed by Munich (7.8%), Münster (6.0%) and Hannover (5.2%). Most ARAF isolates (n = 89) carried the TR34/L98H mutation followed by eight G54E/R, one TR46/Y121F/T289A and one F219S mutation. In two isolates no mutation was found. Genotyping results showed no major clustering. Forty-five percent of CF patients with ARAF had previously received azole therapy. Conclusions: This is the first multicentre study analysing the prevalence of ARAF isolates in German CF patients. Because of a resistance rate of up to 9%, susceptibility testing of A. fumigatus isolates from CF patients receiving antifungal treatment should be part of standard diagnostic work-up.

[Epidemiology, Diagnosis and Treatment of Adult Patients with Nosocomial Pneumonia - Update 2017 - S3 Guideline of the German Society for Anaesthesiology and Intensive Care Medicine, the German Society for Infectious Diseases, the German Society for Hygiene and Microbiology, the German Respiratory Society and the Paul-Ehrlich-Society for Chemotherapy, the German Radiological Society and the Society for Virology]. / Epidemiologie, Diagnostik und Therapie erwachsener Patienten mit nosokomialer Pneumonie ­ Update 2017.

Nosocomial pneumonia (HAP) is a frequent complication of hospital care. Most data are available on ventilator-associated pneumonia. However, infections on general wards are increasing. A central issue are infections with multidrug resistant (MDR) pathogens which are difficult to treat in the empirical setting potentially leading to inappropriate use of antimicrobial therapy.This guideline update was compiled by an interdisciplinary group on the basis of a systematic literature review. Recommendations are made according to GRADE giving guidance for the diagnosis and treatment of HAP on the basis of quality of evidence and benefit/risk ratio.This guideline has two parts. First an update on epidemiology, spectrum of pathogens and antimicrobials is provided. In the second part recommendations for the management of diagnosis and treatment are given. New recommendations with respect to imaging, diagnosis of nosocomial viral pneumonia and prolonged infusion of antibacterial drugs have been added. The statements to risk factors for infections with MDR pathogens and recommendations for monotherapy vs combination therapy have been actualised. The importance of structured deescalation concepts and limitation of treatment duration is emphasized.

In Vitro Activity of Isavuconazole against Rasamsonia Species.

The in vitro susceptibilities to the novel triazole isavuconazole and six other antifungal agents of a large collection of Rasamsonia isolates (n = 47) belonging to seven species were determined. Isavuconazole and voriconazole had no in vitro activity (MIC, >32 mg/liter) against isolates of the Rasamsonia argillacea species complex. The echinocandins were the most potent antifungal drugs against all of the isolates tested (minimum effective concentration, ≤0.19 mg/liter).

Emergence of azole-resistant invasive aspergillosis in HSCT recipients in Germany.

OBJECTIVES: Aspergillus fumigatus is the most common agent of invasive aspergillosis (IA). In recent years, resistance to triazoles, the mainstay of IA therapy, has emerged in different countries worldwide. IA caused by azole-resistant A. fumigatus (ARAF) shows an exceedingly high mortality. In this study, IA due to ARAF isolates in HSCT recipients in Germany was investigated. METHODS: The epidemiology of azole resistance in IA was analysed in two German haematology departments. Between 2012 and 2013, 762 patients received HSCT in Essen (n = 388) and Cologne (n = 374). Susceptibility testing of A. fumigatus isolates was performed by Etest, followed by EUCAST broth microdilution testing if elevated MICs were recorded. In all ARAF isolates the cyp51A gene was sequenced and the genotype was determined by microsatellite typing using nine short tandem repeats. RESULTS: In total, A. fumigatus was recovered from 27 HSCT recipients. Eight patients had azole-resistant IA after HSCT, and seven of the cases were fatal (88%). All except one patient received antifungal prophylaxis (in five cases triazoles). TR34/L98H was the most common mutation (n = 5), followed by TR46/Y121F/T289A (n = 2). In one resistant isolate no cyp51A mutation was detected. Genotyping revealed genetic diversity within the German ARAF isolates and no clustering with resistant isolates from the Netherlands, India and France. CONCLUSIONS: This report highlights the emergence of azole-resistant IA with TR34/L98H and TR46/Y121F/T289A mutations in HSCT patients in Germany and underscores the need for systematic antifungal susceptibility testing of A. fumigatus.

Adaptation of Stenotrophomonas maltophilia in cystic fibrosis: molecular diversity, mutation frequency and antibiotic resistance.

Due to the continuous exposure to a challenging environment and repeated antibiotic treatment courses, bacterial populations in cystic fibrosis (CF) patients experience selective pressure causing the emergence of mutator phenotypes. In this study we investigated the genotypic diversity, mutation frequency and antibiotic resistance of S. maltophilia isolates chronically colonizing CF patients. S. maltophilia was isolated from a total of 90 sputum samples, collected sequentially from 19 CF patients admitted between January 2008 and March 2012 at the University Hospital Essen, Germany. DNA fingerprinting by repetitive-sequence-based PCR revealed that 68.4% (n=13) of CF patients harbored different S. maltophilia genotypes during the 4-year study course. Out of 90 S. maltophilia isolates obtained from chronically colonized CF patients, 17.8% (n=16) were hypomutators, 27.7% (n=25), normomutators, 23.3% (n=21), weak hypermutators and 31.2% (n=28) strong hypermutators. We also found that mutation rates of the most clonally related genotypes varied over time with the tendency to become less mutable. Mutator isolates were found to have no significant increase in resistance against eight different antibiotics versus nonmutators. Sequencing of the mismatch repair genes mutL, mutS and uvrD revealed alterations that resulted in amino acid changes in their corresponding proteins. Here, we could demonstrate that several different S. maltophilia genotypes are present in CF patients and as a sign of adaption their mutation status switches over time to a less mutator phenotype without increasing resistance. These results suggest that S. maltophilia attempts to sustain its biological fitness as mechanism for long-term persistence in the CF lung.

Value of multiplex PCR using cerebrospinal fluid for the diagnosis of ventriculostomy-related meningitis in neurosurgery patients.

PURPOSE: This prospective observational cohort study assessed the use of a multiplex real-time polymerase chain reaction (PCR) assay alone and in conjunction with biomarkers for the diagnosis of ventriculostomy-related meningitis in neurosurgery intensive care unit (ICU) patients with external ventricular drainage (EVD). METHODS: Concentrations of intrathecal biomarkers, including lactate and interleukin 6 (IL-6), were measured, and cerebrospinal fluid (CSF) was examined microbiologically by blood culture BACTEC bottles in 62 CSF samples from 41 patients with EVD. A portion of each sample was also tested with a commercially available PCR assay that simultaneously detects 25 species of bacteria and fungi [SeptiFast (SF)]. Receiver operating characteristic curve analysis was used to compare biomarker concentrations with SF and culture results. RESULTS: Seventeen (27 %) samples tested positive and 40 (65 %) tested negative for pathogens by both culture and SF. One pathogen was detected only by SF. Four samples tested positive by culture but negative by SF; in 3 of these, the isolates were considered to be contaminants. In comparison to CSF culture SF showed a larger area under the curve for IL-6 (0.90; 95 % CI 0.83-0.98) versus 0.70 (95 % CI 0.46-0.80) and for lactate (0.77; 95 % CI 0.63-0.93) versus 0.65 (95 % CI 0.50-0.80). In 94 % (17/18) of positive SF samples the results were obtained on the same day whereas the overall mean of the time-to-positivity of BACTEC bottles was 21.6 h. CONCLUSIONS: The diagnosis of EVD-related ventriculo-meningitis in neurosurgical ICU patients can be established in a rapid manner using a multiplex PCR assay on CSF samples in combination with intrathecal biomarkers.

[Panton-Valentine leukocidin in patients with chronic wounds. Results from a clinical investigation in 100 patients]. / Panton-Valentine Leukozidin in chronischen Wunden. Ergebnisse einer klinischen Untersuchung bei 100 Patienten.

BACKGROUND: The toxin Panton-Valentine leukocidin (PVL) produced by S. aureus is known as a virulence factor that leads to severe infections of skin and soft tissue. However the effect of PVL on wound healing is not known yet. Therefore we examined the detection rate of PVL in patients with chronic wounds. PATIENTS AND METHODS: The study included 100 patients with chronic wounds of the lower limb. We determined in all S. aureus isolates the presence of the PVL gene using a PCR technique. RESULTS: Altogether 94% of the patients had a leg ulcer, while 6% had a foot ulcer; 65% were women. PVL was found in two patients. One of the strains was methicillin-resistant (MRSA) and the other was methicillin-sensitive (MSSA). CONCLUSION: In our investigation there was detection rate for PVL of 2% of all S. aureus isolates in patients with chronic wounds of the lower extremities. Although the role of PVL as a virulence factor of S. aureus in wound healing remains unclear, the detection of PVL should be taken as a cause for a consequent topical antimicrobial wound therapy because of the increased risk of serious infections.

In vitro activity of colistin as single agent and in combination with antifungals against filamentous fungi occurring in patients with cystic fibrosis.

Because published reports indicate that the antibiotic colistin (COL) has antifungal properties, this study investigated the antifungal in vitro activity of COL as single agent and in combination with the antifungal compounds voriconazole (VRC), caspofungin (CAS) and amphotericin B (AMB) against Scedosporium/Pseudallescheria spp., Exophiala dermatitidis and Geosmithia argillacea. In total, susceptibility was determined for 77 Scedosporium/Pseudallescheria spp., 82 E. dermatitidis and 17 G. argillacea isolates. The minimal inhibitory concentrations (MICs) of COL and the antifungals as single compound and in combination were determined with MIC test strips. Drug interactions were detected by crossing the MIC test strips at a 90º angle. The fractional inhibitory concentration index was used to categorise the drugs' interaction. The MIC50 value of COL was 12 µg ml(-1) for S. prolificans, 16 µg ml(-1) for P. apiosperma, 16 µg ml(-1) for P. boydii, 12 µg ml(-1) for E. dermatiditis and 6 µg ml(-1) for G. argillacea. VRC was the most active drug in combination without any antagonism with the exception of few P. boydii isolates. COL as single agent and in most combinations with antifungals exhibits in vitro antifungal activity against filamentous ascomycetes occurring in cystic fibrosis patients and may offer a novel therapeutic option, especially for multidrug-resistant S. prolificans.

Results and relevance of molecular detection of pathogens by SeptiFast--a retrospective analysis in 75 critically ill children.

BACKGROUND: Sepsis is a common cause of death in children. Early detection of bloodstream pathogens is crucial for the appropriate antibio­tic treatment. Blood cultures (BC) are the gold standard test used for detection. Recently, additional molecular detection methods of microbial DNA by multiplex PCR (SeptiFast, SF) have become available. AIM: Our retrospective study was aimed to compare results of BC to those of SF regarding results and therapeutic relevance. METHOD: We identified a total of 110 SF samples in 75 patients with suspected systemic infection by retrospective chart review. Each patient underwent SF and BC testing simultaneously. RESULTS: The initial analysis displayed no statistical significant difference in positive SF results compared to BC (p=0.19): in 26 of 110 samples (24%) microbial DNA was found. 19 BC (17%) showed microbial growth. 14 samples were positive in SF but negative in BC (13%). In patients who were pretreated with antibiotics (n=97) pathogens were identified in 24 samples by SF (25%) but only in 11 samples by BC (11%). Based on the clinical presentation and the spectrum of bacterial isolates 3 BC were considered contaminated. Considering this, SF yielded pathogens significantly more often than BC in the overall study population (p=0.04). SF results were available at least 31 h before BC results. Based on SF result antibiotic therapy was adjusted in 14 patients (13%). CONCLUSION: Molecular detection of pathogens by SF was faster and more frequently positive than BC. We have therefore demonstrated that SF might be superior to BC in testing for bloodstream pathogens. Prospective multicentric studies are required to determine whether this hypothesis can be maintained.

Vancomycin MIC creep in MRSA blood culture isolates from Germany: a regional problem?

The aim of this study was to assess the vancomycin MIC distribution for MRSA blood culture isolates over a period of six years in Germany. The study examined 287 MRSA isolates from blood cultures collected at several hospitals in two German cities between 2004 and 2009. The vancomycin MIC was determined by Etest. Genotypic features of the MRSA strains with vancomycin MIC ≥ 1 mg/L were determined by semiautomated repetitive-sequence-based polymerase chain reaction. The range of vancomycin MIC as determined by Etest was 0.25 to 2.0 mg/L. The geometric mean MIC increased by 1.34-fold in city A over the study period (p < 0.05), but there was no meaningful change in city B (a 1.09-fold increase, p > 0.05). Furthermore, in city A a shift in vancomycin MICs occurred as an increase in the percentage of isolates with MIC ≥ 1 mg/L from period one (2004-2006) to period two (2007-2009) (p < 0.0001). Typing results showed that in city A a single clone was predominant (55% of the creep isolates). In this study, the creep phenomenon seems to be a regional problem. We suggest that all hospitals should monitor their local status of elevated vancomycin MICs in invasive MRSA isolates.

Discrimination of Scedosporium prolificans against Pseudallescheria boydii and Scedosporium apiospermum by semiautomated repetitive sequence-based PCR.

The laboratory identification of Pseudallescheria and Scedosporium isolates at the species level is important for clinical and epidemiological purposes. This study used semiautomated repetitive sequence-based polymerase chain reaction (rep-PCR) to identify Pseudallescheria/Scedosporium. Reference strains of Pseudallescheria boydii (n = 12), Scedosporium prolificans (n = 8), Scedosporium apiospermum (n = 9), and clinical/environmental isolates (P. boydii, 7; S. prolificans, 7; S. apiospermum, 7) were analyzed by rep-PCR. All clinical isolates were identified by morphological and phenotypic characteristics and by sequence analysis. Species identification of reference strains was based on the results of available databases. Rep-PCR studies were also conducted with various molds to differentiate Pseudallescheria/Scedosporium spp. from other commonly encountered filamentous fungi. All tested Pseudallescheria/Scedosporium isolates were distinguishable from the other filamentous fungi. All Scedosporium prolificans strains clustered within the cutoff of 85%, and species identification by rep-PCR showed an agreement of 100% with sequence analysis. However, several isolates of P. boydii and S. apiospermum did not cluster within the 85% cutoff with the same species by rep-PCR. Although the identification of P. boydii and S. apiospermum was not correct, the semiautomated rep-PCR system is a promising tool for the identification of S. prolificans isolates.

Invasive aspergillosis in two liver transplant recipients: diagnosis by SeptiFast.

We report the clinical features, diagnosis, and monitoring findings of invasive aspergillosis (IA) in 2 liver transplant recipients. Blood/serum samples and bronchoalveolar lavage (BAL) fluids were analyzed by a novel commercial polymerase chain reaction (PCR) assay (SeptiFast) and an Aspergillus galactomannan (GM) enzyme-linked immunoassay (EIA). The diagnosis of IA could be performed in <6 h with the detection of Aspergillus fumigatus DNA in blood and BAL fluid. High GM values (mean: 9.1, range: 7.3-10.8) in serum and BAL fluid confirmed the SeptiFast result. Follow-up of the SeptiFast findings and GM index correlated with the clinical course. The molecular detection of A. fumigatus-specific DNA and GM test in blood/serum and BAL samples appears to be a useful tool for prompt diagnosis of IA. Further prospective clinical trials are necessary to evaluate the accuracy of SeptiFast and the GM test in diagnosing IA.

Successful salvage therapy with daptomycin after linezolid and vancomycin failure in a liver transplant recipient with methicillin-resistant Staphylococcus aureus endocarditis.

Infective endocarditis is a rare complication affecting solid organ transplant recipients. Staphylococcus aureus is a common cause of infective endocarditis accounting for about 30% of cases. We present a case of nosocomial methicillin-resistant S. aureus endocarditis with persistent bacteremia, in a patient following orthotopic liver transplantation. We were unable to eradicate this infection with primary linezolid therapy or with secondary treatment with combined vancomycin and rifampicin, but successfully treated it with daptomycin, in addition to tricuspid and aortic valve replacement.

In-vitro activity of active ingredients of disinfectants against drug-resistant fungi.

The biocidal activities of peracetic acid and ethanol were tested against nine clinical fungal isolates and four reference strains. Ethanol was active (≥4.0 log10 reduction) against yeasts at a concentration of 50% v/v and against moulds at 80% v/v. Exposure times in both cases were 1 min. Peracetic acid was active as a 0.25% solution against yeasts and as a 0.5% solution against moulds; exposure times in both cases were 5 min. Compared with the reference strains, clinical isolates, including multi-drug-resistant strains, showed similar or higher sensitivity to the active ingredients of disinfectants in vitro.

Airborne Aspergillus fumigatus spore concentration during demolition of a building on a hospital site, and patient risk determination for invasive aspergillosis including azole resistance.

BACKGROUND: Invasive aspergillosis (IA) in immunocompromised patients has been associated with demolition in or adjacent to hospitals. In recent years, azole-resistant clinical isolates of Aspergillus fumigatus, the most common agent of IA, have emerged in Western Europe and are spreading globally. AIM: To determine the potential risk of IA, including azole resistance, in patients caused by demolition of a hospital building. METHODS: Air sampling before, during and after demolition, screening for azole resistance, genotyping of non-susceptible isolates, and comparing those with strains from patients with azole-resistant IA during demolition. FINDINGS: Mean concentrations of A. fumigatus spores did not differ significantly between the three periods before [17.5 colony-forming units (cfu)/m³], during (20.8 cfu/m³) (P=0.26) and after (17.7 cfu/m³) demolition (P=0.33). No significant difference in IA cases documented by clinicians was found when comparing the timeframe of demolition with the previous year (44 vs 42 cases). Thirty of 200 A. fumigatus isolates (15%) showed azole resistance. Genotyping by microsatellite polymerase chain reaction of the azole-resistant environmental and clinical isolates showed a polyclonal distribution. CONCLUSIONS: The results suggest that with implemented preventive measures, there is no increased risk for IA, including azole resistance, in immunocompromised patients during outdoor demolition work. Further prospective studies are needed to confirm these findings.

Detection of invasive pulmonary aspergillosis in critically ill patients by combined use of conventional culture, galactomannan, 1-3-beta-D-glucan and Aspergillus specific nested polymerase chain reaction in a prospective pilot study.

Invasive pulmonary aspergillosis (IPA) is an emerging and life-threatening infectious disease in patients admitted to the intensive care unit (ICU). Most diagnostic studies are conducted in hematological patients and results cannot readily be transferred to ICU patients lacking classical host factors. In a multicenter, prospective clinical trial including 44 ICU patients, hematological (n = 14) and non-hematological patients (n = 30), concurrent serum and bronchoalveolar lavage (BAL) samples were analyzed by conventional culture, galactomannan (GM), 1-3-beta-D-glucan (BDG) as well as an Aspergillus specific nested polymerase chain reaction (PCR). Nine patients (20%) had putative IPA according to AspICU classification. GM and PCR showed superior performance in BAL with sensitivity/specificity of 56%/94% and 44%/94% compared to 33%/97% and 11%/94% in serum. Despite better sensitivity of 89%, BDG showed poor specificity of only 31% (BAL) and 26% (serum). Combination of GM and PCR (BAL) with BDG (serum) resulted in 100% sensitivity, but also reduced specificity to 23%. Whereas mean GM levels were significantly higher in hematological patients BDG and PCR did not differ between hematological and non-hematological patients. Under present clinical conditions test combinations integrating both BAL and blood samples are advantageous. BDG might best serve as possible indicator for ruling out IPA. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT01695499. First posted: September 28, 2012, last update posted: May 8, 2017.

A prospective international Aspergillus terreus survey: an EFISG, ISHAM and ECMM joint study.

OBJECTIVES: A prospective international multicentre surveillance study was conducted to investigate the prevalence and amphotericin B susceptibility of Aspergillus terreus species complex infections. METHODS: A total of 370 cases from 21 countries were evaluated. RESULTS: The overall prevalence of A. terreus species complex among the investigated patients with mould-positive cultures was 5.2% (370/7116). Amphotericin B MICs ranged from 0.125 to 32 mg/L, (median 8 mg/L). CONCLUSIONS: Aspergillus terreus species complex infections cause a wide spectrum of aspergillosis and the majority of cryptic species display high amphotericin B MICs.

Emergence of linezolid- and vancomycin-resistant Enterococcus faecium in a department for hematologic stem cell transplantation.

BACKGROUND: Prevalence of vancomycin-resistant enterococci has increased in Germany. Here, we report the cluster of linezolid- and vancomycin-resistant Enterococcus faecium (LVRE) in a German department for hematologic stem cell transplantation (HSCT). METHODS: In this retrospective analysis we included all patients with LVRE in a university-based department for HSCT in 2014 and 2015. Patients chart reviews were used to investigate the epidemiology and clinical outcome. Available LVRE isolates underwent detailed microbiological characterization and genotyping by pulsed-field gel electrophoresis (PFGE). RESULTS: In total, 20 patients with LVRE were identified within the observed time period. All except two patients underwent allogeneic HSCT. Surveillance culture results from incoming patients and chart review revealed that 10 of 20 patients were colonized at hospital admission. Eight of 10 patients with in-hospital acquired LVRE had previous linezolid treatment. Analysis of spatio-temporal patterns showed no evidence for LVRE patient-to-patient or environment-to-patient transmission within the HSCT department. In five cases (25 %) LVRE bloodstream infection occurred. Nine LVRE isolates could be saved for characterization. Eight isolates carried vanA, one isolate vanB. PFGE analysis showed that four different LVRE clones were responsible for the cluster. One single genotype was present in six LVRE isolates whereupon the corresponding patients were all referred from the same hospital to the HSCT department. CONCLUSIONS: This is the first report demonstrating the emergence of LVRE in a German HSCT department. (L)VRE screening at patients' admission and appropriate infection control strategies were sufficient to prevent any transmission. Further studies in this predisposed patient collective are warranted.