Heike von Baum

Community-Acquired Legionella Pneumonia: New Insights from the German Competence Network for Community Acquired Pneumonia

BACKGROUND The Competence Network for Community Acquired Pneumonia (CAPNETZ) offers a unique opportunity to study the epidemiology of legionellosis throughout Germany, applying sophisticated diagnostic tools. METHODS The incidence, clinical characteristics, and outcome of Legionella pneumonia in 2503 adult patients with community-acquired pneumonia, participating in the German Multicenter Study of the CAPNETZ, were studied. RESULTS Legionella pneumonia was diagnosed in 94 patients (3.8%), thus identifying Legionella species as one of the most common pathogens to cause community-acquired pneumonia. It was equally common among ambulatory and hospitalized patients (3.7% and 3.8%, respectively). The predominant species causing community-acquired pneumonia was Legionella pneumophila; however, 10% of cases were caused by other species not detectable by the urinary antigen test. Patients whose disease was diagnosed by urinary antigen testing experienced a more severe clinical course. Compared with hospitalized patients, ambulatory patients with Legionella pneumonia showed an equal sex distribution, were younger, had fewer comorbidities, fewer cases of discordant initial antimicrobial treatment, and a milder clinical course without fatalities. Thirty percent of patients with Legionella pneumonia received discordant initial antimicrobial treatment without increased mortality. CONCLUSIONS Legionella is a leading cause of community-acquired pneumonia in Germany. It needs to be considered equally in hospitalized and ambulatory patients. A positive result of a urine antigen test is associated with a more severe clinical course and leads to a potentially relevant underrecognition of species other than L. pneumophila. Legionella pneumonia in outpatients differs significantly from that in hospitalized patients in terms of clinical presentation and outcome. There was an unacceptably high rate of discordant initial antimicrobial treatment.

Impact of Fluoroquinolone Prophylaxis on Reduced Infection-Related Mortality among Patients with Neutropenia and Hematologic Malignancies

BACKGROUND Fluoroquinolone prophylaxis during neutropenia in patients with cancer has been associated with decreased incidence of gram-negative bacteremia. Bacterial antimicrobial resistance is likely to cause a progressive lack of efficacy of fluoroquinolones, but no convincing evidence from clinicoepidemiologic observations has proved this hypothesis. METHODS This prospective observational study assessed the impact of discontinuing fluoroquinolone prophylaxis on the incidences of fever and bacteremia and on mortality among patients with neutropenia, after chemotherapy for hematologic malignancies. RESULTS After a 12-month baseline period of levofloxacin prophylaxis, a period of discontinuation of fluoroquinolone prophylaxis was planned but was stopped prematurely after 9 neutropenic episodes over 3 weeks, because the mortality rate (33.3%) was higher than that with routine fluoroquinolone prophylaxis (2.9%) (odds ratio [OR], 16.6; 95% confidence interval [CI], 3.6-77.2). Fewer patients had gram-negative bacteremia during the baseline period (4.8%; n=15) than during the discontinuation period (44.4%; n=4) (OR, 16.9; 95% CI, 4.1-70.0). After levofloxacin therapy was reintroduced, the incidence of gram-negative bacteremia and the mortality rate were comparable to those during the first period. Escherichia coli isolated during the discontinuation period was susceptible to levofloxacin in vitro, whereas all E. coli isolates isolated during both prophylaxis periods were resistant. Bloodstream infections were caused by a single agent when the patient had received levofloxacin prophylaxis, whereas most cases of gram-negative bacteremia were polymicrobial after discontinuation. CONCLUSIONS These findings suggest that, despite increasing rates of antimicrobial resistance, levofloxacin prophylaxis during neutropenia may have a beneficial impact on morbidity and infection-related mortality. Continued monitoring of the rate of gram-negative bacteremia is warranted for timely detection of the loss of efficacy of fluoroquinolone prophylaxis.

Pro-atrial natriuretic peptide and pro-vasopressin to predict severity and prognosis in community-acquired pneumonia: results from the German competence network CAPNETZ.

ObjectiveCommunity acquired pneumonia (CAP) is the most important clinical infection. Therefore, the CAP competence network CAPNETZ was instituted in Germany. The aim of this substudy was to evaluate the value of pro-atrial natriuretic peptide (MR-proANP) and pro-vasopressin (CT-proAVP) for severity assessment and outcome prediction in CAP.DesignProspective observational study.SettingGerman CAP competence network CAPNETZ.MethodsWe enrolled 589 patients (age 61 ± 18 years, 46% female) with proven CAP. MR-proANP, CT-proAVP, C-reactive protein (CRP), procalcitonin (PCT) and CRB-65 score were determined on admission.ResultsMR-proANP, CT-proAVP and PCT levels, but not CRP, increased with increasing severity of CAP, classified according to the CRB-65 score. In patients who died during 28-day follow-up, median MR-proANP and CT-proAVP levels (respectively 237.0 vs. 93.5 pmol/l and 44.2 vs. 12.4 pmol/l, each p < 0.0001) were significantly higher than in survivors. In receiver operating characteristic (ROC) analysis for survival, the area under the curve (AUC) values for CT-proAVP (0.86, 95% CI 0.83–0.89) and MR-proANP (0.76, 95% CI 0.72–0.80) were similar to the AUC of CRB-65 (0.73, 95% CI 0.70–0.77). In multivariable Cox proportional-hazards regression analyses including MR-proANP/CT-proAVP, coexisting illnesses and CRB-65, increased MR-proANP and CT-proAVP concentrations were the strongest predictors of mortality.ConclusionsMR-proANP and CT-proAVP are useful new biomarkers for the risk stratification of CAP patients. They are significantly lower in CAP survivors and correlate with the severity of the disease measured by CRB-65 score.

Inflammatory parameters predict etiologic patterns but do not allow for individual prediction of etiology in patients with CAP – Results from the German competence network CAPNETZ

BackgroundAim of this study was to evaluate the correlation of inflammatory markers procalcitonin (PCT), C-reactive protein (CRP) and leukocyte count (WBC) with microbiological etiology of CAP.MethodsWe enrolled 1337 patients (62 ± 18 y, 45% f) with proven CAP. Extensive microbiological workup was performed. In all patients PCT, CRP, WBC and CRB-65 score were determined. Patients were classified according to microbial diagnosis and CRB-65 score.ResultsIn patients with typical bacterial CAP, levels of PCT, CRP and WBC were significantly higher compared to CAP of atypical or viral etiology. There were no significant differences in PCT, CRP and WBC in patients with atypical or viral etiology of CAP. In contrast to CRP and WBC, PCT markedly increased with severity of CAP as measured by CRB-65 score (p < 0.0001). In ROC analysis for discrimination of patients with CRB-65 scores > 1, AUC for PCT was 0.69 (95% CI 0.66 to 0.71), which was higher compared to CRP and WBC (p < 0.0001). CRB-65, PCT, CRP and WBC were higher (p < 0.0001) in hospitalised patients in comparison to outpatients.ConclusionPCT, CRP and WBC are highest in typical bacterial etiology in CAP but do not allow individual prediction of etiology. In contrast to CRP and WBC, PCT is useful in severity assessment of CAP.

Culture-Independent Molecular Subtyping of Mycoplasma pneumoniae in Clinical Samples

ABSTRACT A new molecular subtyping approach was developed which is based on the amplification and sequencing of a repetitive region of the P1 gene of Mycoplasma pneumoniae. It allows the differentiation of all known subtypes and variants of M. pneumoniae as well as the identification of new subtypes directly in clinical samples to characterize endemic and epidemic M. pneumoniae infections.

Low prevalence of fluoroquinolone resistant strains and resistance precursor strains in Streptococcus pneumoniae from patients with community-acquired pneumonia despite high fluoroquinolone usage

We investigated the usage of fluoroquinolones and the prevalence of fluoroquinolone resistant pneumococci and their precursors (first step mutants and efflux expressing isolates) in patients with community-acquired pneumonia, who were enroled into the German CAPNETZ surveillance study from 2002 to 2006 before the introduction of the pneumococcal conjugate vaccine (n=5780). Thirty-eight percent of all outpatients received fluoroquinolones. Moxifloxacin accounted for 70%, levofloxacin for 19% and ciprofloxacin for 9% of all fluoroquinolone prescriptions. One hundred and sixty-three pneumococcal isolates from 556 patients with pneumococcal pneumonia were analyzed for fluoroquinolone resistance, efflux phenotype, prevalence of mutations within the quinolone-resistance determining regions and clonality. None of the isolates exhibited fluoroquinolone resistance, 1.2% of the isolates contained a first step mutation and 6.7% exhibited an efflux phenotype. There was no clonal relationship among these strains at increased risk for fluoroquinolone resistance. The absence of fluoroquinolone resistance in the context of high fluoroquinolone usage might be explained by the high proportion of third-generation fluoroquinolones with enhanced activity against pneumococci.

Prevalence of Vancomycin-Resistant Enterococci Among Children with End-Stage Renal Failure

To evaluate the prevalence of colonization with vancomycin-resistant enterococcus (VRE) in end-stage renal failure (ESRF), we screened the intestinal flora from 338 pediatric ESRF patients treated in 13 pediatric nephrology units in mid-Europe. Eighty-one patients were undergoing hemodialysis, 66 were undergoing chronic peritoneal dialysis, and 191 were transplant recipients. A total of 363 enterococcal strains were recovered from 232 patients. Twenty-seven enterococcal strains from 24 patients (7.1%) had reduced susceptibility to vancomycin (minimal inhibitory concentration [MIC], >4 microg/mL). Although two patients (0.6%) carried enterococci with high-level resistance to vancomycin (MIC, >32 microg/mL; i.e., VRE), strains of enterococcus with reduced susceptibility to vancomycin (ERSV) were recovered from the other 22 subjects. Past use of vancomycin (P = .05) and tacrolimus therapy (P = .011) were independent risk factors for ERSV or VRE carriage. Enterococcal infections occurred with a similar frequency among enterococcal carriers and noncarriers; no infections with VRE or ERSV were reported. In conclusion, the prevalence of ERSV carriage and the rate of VRE colonization among mid-European children and adolescents with ESRF currently are moderate and low, respectively.

Acridine-orange leucocyte cytospin (AOLC) test as an in-situ method for the diagnosis of central venous catheter (CVC)-related sepsis in adult risk patients

The AOLC method for the in-situ diagnosis of catheter-associated septicemia was evaluated in adult intensive care patients. 55 blood samples and corresponding CVC tips were examined using the AOLC method, the semiquantitative roll plate method and the broth immersion method. In 4 patients (7.3%), a CVC-related septicemia was diagnosed, 10 patients (18.2%) showed a colonisation of their central venous access. The AOLC method was positive in 50% of the cases with CVC-related septicemia and in 20% of the colonized patients. Thus, we do not recommend the AOLC test as a routine method for the diagnosis of suspected CVC-related infection but as a facultative additional diagnostic measure for certain risk patients.

Wenn der Vater mit dem Sohne

Ein 32-jahriger Ingenieur, bei dem seit 1979 eine hereditare Spharozytose bekannt ist, erkrankt Mitte Januar 1997 aus volligem Wohlbefinden heraus akut mit Schuttelfrost und Temperaturen bis 40°C, sowie Gelenk- und Gliederschmerzen. Die Schwere des Krankheitsbildes veranlasst den Hausarzt unter der Verdachtsdiagnose einer Pneumonie die sofortigen Einweisung in ein peripheres Krankenhaus.

KPC-2 carbapenemase-producing Pseudomonas aeruginosa reaching Germany

Background Antimicrobial resistance due to carbapenemase expression poses a worldwide threat in healthcare. Inter-genus exchange of genetic information is of utmost importance in this context. Objectives Here, to the best of our knowledge, we describe the first detection and characterization of a KPC-2-producing Pseudomonas aeruginosa in Germany. Methods Characterization of the isolate was performed using MALDI-TOF MS, automated microdilution and MLST. Carbapenemase detection was performed using phenotypic and genotypic assays. The blaKPC-2-carrying plasmid was transformed into Escherichia coli NEB® 10-beta. The purified plasmid DNA was sequenced using the Illumina technique. Results The isolate expressed ST235 and was resistant to carbapenems. Antimicrobial susceptibility testing revealed colistin to be the only antimicrobial agent active in vitro. The blaKPC-2 gene was located on a replicon type lncHI1 plasmid as part of Tn4401. Conclusions The first detection (to the best of our knowledge) of plasmid-encoded KPC-2 in P. aeruginosa in Germany may point to a currently underestimated spread of carbapenemases among clinically relevant Gram-negative bacteria. Here, to the best of our knowledge, we also provide the first report of blaKPC-2 associated with the IncHI1 plasmid.