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2.
BMC Biol ; 17(1): 76, 2019 09 18.
Artigo em Inglês | MEDLINE | ID: mdl-31533707

RESUMO

BACKGROUND: The selection pressure exercised by antibiotic drugs is an important consideration for the wise stewardship of antimicrobial treatment programs. Treatment decisions are currently based on crude assumptions, and there is an urgent need to develop a more quantitative knowledge base that can enable predictions of the impact of individual antibiotics on the human gut microbiome and resistome. RESULTS: Using shotgun metagenomics, we quantified changes in the gut microbiome in two cohorts of hematological patients receiving prophylactic antibiotics; one cohort was treated with ciprofloxacin in a hospital in Tübingen and the other with cotrimoxazole in a hospital in Cologne. Analyzing this rich longitudinal dataset, we found that gut microbiome diversity was reduced in both treatment cohorts to a similar extent, while effects on the gut resistome differed. We observed a sharp increase in the relative abundance of sulfonamide antibiotic resistance genes (ARGs) by 148.1% per cumulative defined daily dose of cotrimoxazole in the Cologne cohort, but not in the Tübingen cohort treated with ciprofloxacin. Through multivariate modeling, we found that factors such as individual baseline microbiome, resistome, and plasmid diversity; liver/kidney function; and concurrent medication, especially virostatic agents, influence resistome alterations. Strikingly, we observed different effects on the plasmidome in the two treatment groups. There was a substantial increase in the abundance of ARG-carrying plasmids in the cohort treated with cotrimoxazole, but not in the cohort treated with ciprofloxacin, indicating that cotrimoxazole might contribute more efficiently to the spread of resistance. CONCLUSIONS: Our study represents a step forward in developing the capability to predict the effect of individual antimicrobials on the human microbiome and resistome. Our results indicate that to achieve this, integration of the individual baseline microbiome, resistome, and mobilome status as well as additional individual patient factors will be required. Such personalized predictions may in the future increase patient safety and reduce the spread of resistance. TRIAL REGISTRATION: ClinicalTrials.gov, NCT02058888 . Registered February 10 2014.

3.
Int J Med Microbiol ; 309(6): 151336, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31444102

RESUMO

Cryptococcosis is a fungal infection of the central nervous system predominantly caused by Cryptococcus neoformans in immunocompromised patients. In several countries worldwide, up to 50% of isolates show in vitro resistance to clinically used antifungals including fluconazole. No prospective data on susceptibility to antifungal drugs are available for Germany. In this study, we characterised all C. neoformans isolates collected from individual patients' samples at the German reference laboratory for cryptococcosis 2011 and 2017 (n = 133) by multi-locus sequence typing and phenotypic drug susceptibility testing. We identified serotype A/genotype VNI isolates belonging to clonal complexes previously described from Europe, Africa, Asia and South America as the most prevalent agents of cryptococcosis in Germany. Overall, we observed minimal inhibitory concentrations (MICs) above the epidemiological cut-offs (ECVs) in 1.6% of isolates regarding fluconazole and 2.3% of isolates regarding 5-flucytosine. Here, two C. neoformans var. grubii isolates displayed decreased drug susceptibility to fluconazole, one of them additionally to 5-flucytosine. We also found 5-flucytosine MICs above the ECV for two C. neoformans var. neoformans isolates. We identified a novel mutation in the ERG11 gene which might be associated with the elevated fluconazole MIC in one of the isolates. The clinical importance of the detected in vitro resistance is documented by patient histories showing relapsed infection or primary fatal disease. Of note, sertraline demonstrated antifungal activity comparable to previous reports. Systematic collection of susceptibility data in combination with molecular typing of C. neoformans is important to comprehensively assess the spread of isolates and to understand their drug resistance patterns.

4.
J Clin Microbiol ; 57(11)2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31413083

RESUMO

Early identification of infections caused by carbapenemase-producing Enterobacterales (CPE) can help to optimize patient treatment and improve outcome. In this study, protocols for rapid detection of carbapenemase production directly from positive blood cultures were developed applying a concentration and hemolysis step before a test for carbapenemase production was performed. Four different methods (three modified colorimetric assays [ß-Carba, bcCarba NP, and NeoRapid Carb] and a variation of the carbapenem inactivation method [CIM] test with blood cultures [bcCIM]) were assessed on blood cultures spiked with 185 different molecularly characterized Enterobacterales isolates. The challenge collection included 81 carbapenemase-negative isolates and 104 CPEs (OXA-48 [n = 25], NDM [n = 20], KPC [n = 18], VIM [n = 25], GIM [n = 5], OXA-48-like [n = 9], and OXA-48-like plus NDM [n = 2]). The sensitivity/specificity was 99.0%/95.1% for bcCarba NP, 99.0%/91.4% for NeoRapid Carb, 100%/95.1% for ß-Carba and 100%/100% for bcCIM. Weakly hydrolyzing carbapenemases (e.g., OXA-48-like) were also well detected by the assays. The time to result was 20 to 45 min for ß-Carba, 2 to 3 h for bcCarba NP, 2.5 to 2 h for NeoRapid Carb, and 18 to 24 h for bcCIM. In conclusion, all assays demonstrated good detection of CPE. The protocols can be easily implemented in any clinical microbiology laboratory and could help to optimize therapy early in bloodstream infections by CPE.

5.
J Antimicrob Chemother ; 74(10): 2926-2929, 2019 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-31335935

RESUMO

OBJECTIVES: In 2018, EUCAST issued a warning regarding unreliable results of gradient strip tests for confirming vancomycin resistance in enterococci. We compared the performance of various diagnostic standard and confirmatory tests to identify and determine vanB-type vancomycin resistance. METHODS: We analysed a collection of vanB-positive Enterococcus faecium isolates (n = 68) with low vancomycin MICs and compared the performance of VITEK® 2 (bioMérieux), broth microdilution and three gradient strip tests from different providers (Oxoid, Liofilchem and bioMérieux). For the latter we compared the standard procedure with a protocol with increased inoculum, a rich agar medium and a longer incubation time ('macromethod'). RESULTS: The sensitivity of VITEK® 2 was 81% compared with 72% for broth microdilution and 61%-63% for the three gradient strip tests using standard conditions. The macromethod substantially improved the performance of all strip tests resulting in a sensitivity of 89%-96% after 48 h of incubation. CONCLUSIONS: We recommend that EUCAST changes the present warning against the general use of MIC strips. When MIC strips are used to either exclude or confirm suspected vancomycin resistance in E. faecium, and a PCR is not available, the macromethod should be employed. For clinically relevant enterococci, where a rapid therapeutic decision is needed, a molecular test (e.g. PCR) should be favoured in order to save time and to further increase sensitivity.

6.
J Clin Microbiol ; 57(9)2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31315949

RESUMO

The novel, real-time PCR-based GenePOC Carba assay on the microfluidic revogene platform (GenePOC, Québec, Canada; now Meridian Bioscience, Cincinnati, OH, USA) was recently designed for the detection of bla KPC, bla NDM, bla VIM, bla OXA-48-like, and bla IMP The goals of this study were to evaluate the performance of this assay, to assess its suitability for the routine microbiology laboratory, and to compare it to the Xpert Carba-R assay for the detection of carbapenemase-producing Enterobacterales (CPE) strains. The Xpert Carba-R assay (Cepheid) and the GenePOC Carba assay were challenged with a collection of 176 clinical Enterobacterales isolates. The collection included 133 CPE strains producing a total of 139 carbapenemases, including VIM (n = 48), OXA-48-like (n = 40), NDM (n = 29), KPC (n = 13), and IMP (n = 9). Six isolates produced two different carbapenemases, and 43 carbapenemase-negative isolates were included as negative controls. The overall sensitivity for carbapenemase detection was 96.4% (95% confidence interval [CI], 91.9% to 98.5%) for the Xpert Carba-R assay and 100% (95% CI, 97.3% to 100%) for the GenePOC assay. The four most common carbapenemases (NDM, KPC, OXA-48-like, and VIM) were detected with a sensitivity of 100% (95% CI, 97.1% to 100%) by the two tests, with all double carbapenemase producers being correctly detected by both assays. The sensitivity of the Xpert Carba-R assay for IMP was 44.4% (95% CI, 18.9% to 73.3%), while that of the GenePOC assay was 100% (95% CI, 70.1% to 100%). The specificity of both assays was 100% (95% CI, 91.8% to 100%). The GenePOC Carba assay showed excellent sensitivity and specificity for the five most common carbapenemases, including IMP variants. Its simplicity and short turnaround time make it suitable for use in the routine microbiology laboratory for CPE detection.

7.
Mycoses ; 62(10): 920-927, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31271702

RESUMO

BACKGROUND: Recent outbreaks of Candida auris further exemplify that invasive Candida infections are a substantial threat to patients and healthcare systems. Even short treatment delays are associated with higher mortality rates. Epidemiological shifts towards more resistant Candida spp. require careful surveillance. OBJECTIVES: Triggered by the emergence of C auris and by increasing antifungal resistance rates the European Confederation of Medical Mycology developed an international Candida Registry (FungiScope™ CandiReg) to allow contemporary multinational surveillance. METHODS: CandiReg serves as platform for international cooperation to enhance research regarding invasive Candida infections. CandiReg uses the General Data Protection Regulation compliant data platform ClinicalSurveys.net that holds the electronic case report forms (eCRF). Data entry is supported via an interactive macro created by the software that can be accessed via any Internet browser. RESULTS: CandiReg provides an eCRF for invasive Candida infections that can be used for a variety of studies from cohort studies on attributable mortality to evaluations of guideline adherence, offering to the investigators of the 28 ECMM member countries the opportunity to document their cases of invasive Candida infection. CandiReg allows the monitoring of epidemiology of invasive Candida infections, including monitoring of multinational outbreaks. Here, we describe the structure and management of the CandiReg platform. CONCLUSION: CandiReg supports the collection of clinical information and isolates to improve the knowledge on epidemiology and eventually to improve management of invasive Candida infections. CandiReg promotes international collaboration, improving the availability and quality of evidence on invasive Candida infection and contributes to improved patient management.

8.
J Antimicrob Chemother ; 74(10): 2934-2937, 2019 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-31292653

RESUMO

BACKGROUND: Infections caused by carbapenemase-producing Enterobacterales (CPE) constitute a major global health concern and are associated with increased morbidity and mortality. Nitroxoline is an old antibiotic, which has recently been re-launched for the treatment of uncomplicated urinary tract infection. Because of low resistance rates it could be an interesting option for treatment of MDR isolates, yet data on CPE susceptibility are scarce. OBJECTIVES: To analyse the in vitro activity of nitroxoline against CPE. METHODS: MICs of nitroxoline were determined by agar dilution for a collection of well-characterized carbapenemase producers (n = 105), producing OXA-48-like (n = 36), VIM (n = 21), IMI (n = 9), IMP (n = 6), NDM (n = 22), KPC (n = 11), OXA-58 (n = 2) and GES (n = 2). For comparison, MICs of ertapenem, imipenem and meropenem were determined by agar gradient diffusion. RESULTS: For all 105 isolates, the MIC50/90 of nitroxoline was 8/16 mg/L. All Escherichia coli isolates (30/30, 100%) showed low MICs of 2-8 mg/L and were susceptible to nitroxoline. MICs of 32 mg/L were recorded for five isolates of VIM- and IMI-producing Enterobacter cloacae (n = 3) and OXA- and VIM-producing Klebsiella pneumoniae (n = 2). CONCLUSIONS: Nitroxoline exhibited excellent in vitro activity against most isolates producing common and rare carbapenemases. If the current EUCAST susceptibility breakpoint of ≤16 mg/L for E. coli in uncomplicated urinary tract infections was applied, 95.2% (100/105) of isolates would be classified as susceptible. Nitroxoline could therefore be an alternative oral option for treatment of uncomplicated urinary tract infections caused by CPE.

9.
J Med Microbiol ; 68(7): 991-995, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31162022

RESUMO

In 2018, the European Centre for Disease Prevention and Control reported the first cases of extensively drug-resistant Neisseria gonorrhoeae infections in Europe. Seeking new options for antimicrobial therapy we investigated the susceptibility of N. gonorrhoeae to nitroxoline (NIT) and mecillinam (MCM), both of which are currently only indicated to treat uncomplicated urinary tract infections. Clinical N. gonorrhoeae isolates with non-susceptibility to penicillin from two German medical centres were included (n =27). Most isolates were also non-susceptible to a range of other anti-gonococcal antimicrobials (cefotaxime, ciprofloxacin, azithromycin, tetracycline). All isolates were further characterized by multi-locus sequence typing. MICs of penicillin and cefotaxime were determined by agar gradient diffusion. Production of penicillinase was tested by cefinase disk test. Susceptibility of MCM was investigated by agar dilution, NIT by agar dilution and disk diffusion. Penicillin MICs ranged from 0.125 to 64 mg l-1 and MICs of cefotaxime ranged from < 0.016 to 1 mg l-1 . Five isolates were penicillinase-producers. MICs of MCM ranged from 16 to > 128 mg l-1 whereas MICs of NIT ranged from 0.125 to 2 mg l-1 . NIT disk diffusion (median zone diameter 32 mm) correlated well with results from agar dilution. We demonstrated excellent in vitro activity of NIT against clinical N. gonorrhoeae isolates with non-susceptibility to standard anti-gonococcal antibiotics. MCM activity was unsatisfactory. Correlation of agar dilution and disk diffusion in NIT susceptibility testing is an important aspect with potential clinical implications.


Assuntos
Andinocilina/farmacologia , Anti-Infecciosos Urinários/farmacologia , Neisseria gonorrhoeae/efeitos dos fármacos , Nitroquinolinas/farmacologia , Farmacorresistência Bacteriana Múltipla , Humanos , Tipagem de Sequências Multilocus , Neisseria gonorrhoeae/genética
10.
J Antimicrob Chemother ; 74(7): 2065-2074, 2019 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-31220256

RESUMO

OBJECTIVES: We assessed the efficacy and safety of an oral antimicrobial regimen for short- and long-term intestinal eradication of ESBL-producing Escherichia coli and Klebsiella pneumoniae (ESBL-EC/KP) in immunocompromised patients. METHODS: We performed a randomized (2:1), double-blind multicentre Phase II study in four haematology-oncology departments. Patients colonized with ESBL-EC/KP received a 7 day antimicrobial regimen of oral colistin (2 × 106 IU 4×/day), gentamicin (80 mg 4×/day) and fosfomycin (three administrations of 3 g every 72 h), or placebo. Faecal, throat and urine specimens were collected on day 0, 6 ± 2, 11 ± 2, 28 ± 4 and 42 ± 4 after treatment initiation, and the quantitative burden of ESBL-EC/KP, resistance genes and changes in intestinal microbiota were analysed. Clinicaltrials.gov: NCT01931592. RESULTS: As the manufacture of colistin powder was suspended worldwide, the study was terminated prematurely. Overall, 29 (18 verum/11 placebo) out of 47 patients were enrolled. The short-term intestinal eradication was marginal at day 6 (verum group 15/18, 83.3% versus placebo 2/11, 18.2%; relative risk 4.58, 95% CI 1.29-16.33; Fisher's exact test P = 0.001) and not evident at later timepoints. Quantitative analysis showed a significant decrease of intestinal ESBL-EC/KP burden on day 6. Sustained intestinal eradication (day 28 + 42) was not achieved (verum, 38.9% versus placebo, 27.3%; P = 0.299). In the verum group, mcr-1 genes were detected in two faecal samples collected after treatment. Microbiome analysis showed a significant decrease in alpha diversity and a shift in beta diversity. CONCLUSIONS: In this prematurely terminated study of a 7 day oral antimicrobial eradication regimen, short-term ESBL-EC/KP suppression was marginal, while an altered intestinal microbiota composition was clearly apparent.

11.
Emerg Infect Dis ; 25(9): 1763-1765, 2019 09.
Artigo em Inglês | MEDLINE | ID: mdl-31223105

RESUMO

The emerging yeast Candida auris has disseminated worldwide. We report on 7 cases identified in Germany during 2015-2017. In 6 of these cases, C. auris was isolated from patients previously hospitalized abroad. Whole-genome sequencing and epidemiologic analyses revealed that all patients in Germany were infected with different strains.

12.
Mycoses ; 62(7): 562-569, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31034691

RESUMO

Invasive mould infections (IMI) in immunocompromised patients are difficult to diagnose. Early and targeted treatment is paramount, but minimally invasive tests reliably identifying pathogens are lacking. We previously showed that monitoring pathogen-specific CD4+T cells in peripheral blood using upregulation of induced CD154 positive lymphocytes can be used to diagnose acute IMI. Here, we validate our findings in an independent patient cohort. We stimulated peripheral blood cells from at-risk patients with Aspergillus spp. and Mucorales lysates and quantitated mould-reactive CD4/CD69/CD154 positive lymphocytes via flow cytometry. Mould-reactive lymphocytes were quantitated in 115 at-risk patients. In 38 (33%) patients, the test was not evaluable, mainly due to low T cell counts or non-reactive positive control. Test results were evaluable in 77 (67%) patients. Of these, four patients (5%) had proven IMI and elevated mould-reactive T cell signals. Of 73 (95%) patients without proven IMI, 59 (81%) had mould-reactive T cell signals within normal range. Fourteen (19%) patients without confirmed IMI showed elevated T cell signals and 11 of those received antifungal treatment. The mould-reactive lymphocyte assay identified presence of IMI with a sensitivity of 100% and specificity of 81%. The mould-reactive lymphocyte assay correctly identified all patients with proven IMI. Assay applicability is limited by low T cell counts during bone marrow suppression. The assay has the potential to support diagnosis of invasive mould infection to facilitate tailored treatment even when biopsies are contraindicated or cultures remain negative.


Assuntos
Aspergillus/imunologia , Linfócitos T CD4-Positivos/imunologia , Infecções Fúngicas Invasivas/diagnóstico , Mucorales/imunologia , Subpopulações de Linfócitos T/imunologia , Adolescente , Adulto , Idoso , Antígenos CD/análise , Antígenos de Diferenciação de Linfócitos T/análise , Linfócitos T CD4-Positivos/química , Ligante de CD40/análise , Feminino , Citometria de Fluxo , Humanos , Hospedeiro Imunocomprometido , Lectinas Tipo C/análise , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Sensibilidade e Especificidade , Subpopulações de Linfócitos T/química , Adulto Jovem
13.
Artigo em Inglês | MEDLINE | ID: mdl-30917983

RESUMO

The activity of mecillinam (amdinocillin) was assessed in Enterobacterales (n = 420) isolated from urine samples between 2016 and 2017. Mecillinam susceptibilities were 97.4% in Escherichia coli isolates (294/302), 89.7% in Klebsiella spp. isolates (52/58), and 93.3% in Proteus mirabilis isolates (28/30). Among extended-spectrum ß-lactamase (ESBL) producers, 95.2% (99/104) were mecillinam susceptible, including two OXA-48-producing Klebsiella pneumoniae isolates. In Enterobacter spp. and Citrobacter spp., MICs were low (MIC50 = 0.5 mg/liter). In conclusion, the activity of mecillinam was high in Enterobacterales, even among multidrug-resistant isolates.

14.
Crit Rev Microbiol ; 45(1): 1-21, 2019 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-30628529

RESUMO

Invasive Scedosporium spp. and Lomentospora prolificans infections are an emerging threat in immunocompromised and occasionally in healthy hosts. Scedosporium spp. is intrinsically resistant to most, L. prolificans to all the antifungal drugs currently approved, raising concerns about appropriate treatment decisions. High mortality rates of up to 90% underline the need for comprehensive diagnostic workup and even more for new, effective antifungal drugs to improve patient outcome. For a comprehensive analysis, we identified cases of severe Scedosporium spp. and L. prolificans infections from the literature diagnosed in 2000 or later and the FungiScope® registry. For 208 Scedosporium spp. infections solid organ transplantation (n = 58, 27.9%) and for 56 L. prolificans infection underlying malignancy (n = 28, 50.0%) were the most prevalent risk factors. L. prolificans infections frequently presented as fungemia (n = 26, 46.4% versus n = 12, 5.8% for Scedosporium spp.). Malignancy, fungemia, CNS and lung involvement predicted worse outcome for scedosporiosis and lomentosporiosis. Patients treated with voriconazole had a better overall outcome in both groups compared to treatment with amphotericin B formulations. This review discusses the epidemiology, prognostic factors, pathogen susceptibility to approved and investigational antifungals, and treatment strategies of severe infections caused by Scedosporium spp. and L. prolificans.


Assuntos
Infecções Fúngicas Invasivas/diagnóstico , Infecções Fúngicas Invasivas/patologia , Scedosporium/isolamento & purificação , Adulto , Idoso , Antifúngicos/uso terapêutico , Feminino , Humanos , Hospedeiro Imunocomprometido , Infecções Fúngicas Invasivas/microbiologia , Infecções Fúngicas Invasivas/mortalidade , Masculino , Pessoa de Meia-Idade , Neoplasias/complicações , Transplante de Órgãos/efeitos adversos , Prognóstico , Fatores de Risco , Análise de Sobrevida , Resultado do Tratamento , Voriconazol/uso terapêutico
15.
Artigo em Inglês | MEDLINE | ID: mdl-30448931

RESUMO

The rapid detection of carbapenemase-producing Gram-negative bacteria is indispensable to optimize treatment and avoid the further spread of these organisms. While phenotypic tests are time-consuming and PCR is expensive and not available in many routine laboratories, immunochromatographic tests (ICT) can provide rapid results at moderate cost. The aim of this study was to determine the performance of the new ICT RESIST-4 O.K.N.V. K-SeT (Coris BioConcept, Gembloux, Belgium) which can detect the four most prevalent carbapenemases: OXA-48-like, KPC, NDM, and VIM. Additionally, we analyzed the impact of different culture conditions on the sensitivity. The new ICT was challenged with 169 carbapenem-resistant isolates. Of these, 125 were carbapenemase producers: 43 OXA-48-like, 15 KPC, 29 NDM, and 43 VIM. The ICT correctly detected 129 of the 130 carbapenemases resulting in a sensitivity of 99.2% and specificity of 100% when tested from Mueller-Hinton agar (MHA). The sensitivity of the assay increased to 100% when performed from zinc-supplemented MHA and sheep blood agar (SBA) or when the inoculum was harvested from the inhibition zone of an ertapenem disk. All carbapenemase-negative carbapenem-resistant bacteria tested negative and no cross-reaction was observed. The new ICT is an excellent test for rapid diagnostic of carbapenemase-producing Gram-negatives in the routine laboratory. It is easy to handle and provides rapid results with a high sensitivity. For best results, we recommend to obtain the inoculum from a medium with sufficient zinc or from the inhibition zone of an ertapenem disk.

16.
Artigo em Inglês | MEDLINE | ID: mdl-30411220

RESUMO

The rapid detection of blood stream infections (BSI) by carbapenemase-producing Enterobacterales (CPE) is indispensable to early optimize antibiotic treatment and to improve survival. While phenotypic tests are time-consuming and PCR is expensive and not available in many routine laboratories, colorimetric tests (e.g., Carba NP test) can provide rapid results at moderate cost. However, up to now, the detection of CPE-BSI requires a further 3-h incubation in broth supplemented with zinc sulfate and imipenem after a blood culture has become positive, thereby causing delay and additional hands-on time. The purpose of this study was to develop and evaluate a new method for the detection of CPE directly from positive blood culture without the need for incubation in broth, based on the commercially available colorimetric ß-CARBA test. For the evaluation, blood cultures spiked with 140 different Enterobacterales isolates producing diverse beta-lactamases were tested with the new method. Of these, 70 were CPE (OXA-48-like, NDM, KPC, VIM, and GIM). After blood cultures turned positive, blood culture fluid was drawn, and erythrocytes were hemolyzed with SDS, washed, and equilibrated before the ß-CARBA was performed on the bacterial pellet. All carbapenemases were reliably detected, including weak carbapenemases of the OXA-48 group. The sensitivity was 100% (95% CI 94.9-100) and the specificity 94.3% (95% CI 89.2-99.4). The time to result was 20 to 45 min. Carbapenemases can rapidly and reliably be detected directly from blood cultures using the new method, which could help to improve the outcome of these difficult-to-treat infections.

17.
PLoS One ; 13(9): e0204157, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30216371

RESUMO

Bloodstream infections caused by carbapenemase-producing Enterobacteriaceae (CPE) are associated with treatment failure and increased mortality. Detection of CPE from blood cultures (BC) by standard methods takes 16-72 hours, which can delay the initiation of appropriate antimicrobial therapy and compromise patient outcome. In the present study, we developed and evaluated a new method for the rapid detection of carbapenemases directly from positive BC using a new multiplex immunochromatographic test (ICT). The new ICT was assessed using 170 molecularly characterized Enterobacteriaceae clinical isolates including 126 CPE (OXA-48-like (N = 79), KPC (N = 18) and NDM (N = 29)). After spiking with bacteria and incubation in a BC system, blood from positive BC bottles was hemolyzed, bacteria concentrated by centrifugation and lysed. The lysate was transferred to the RESIST-3 O.K.N. ICT (Coris BioConcept, Gembloux, Belgium), which detects OXA-48-like, KPC and NDM carbapenemases. The final results of the ICT were read when they became positive, at the latest after 15 min. All CPE isolates (126/126) were correctly detected with the new protocol (100% sensitivity, 100% specificity). There was perfect concordance between ICT results and molecular characterization. Total time to result was 20-45 min. CONCLUSIONS: This proof-of-principle study demonstrates that with the newly developed method, OXA-48-like, KPC and NDM carbapenemases can be reliably detected directly from positive BC bottles. The new method is more rapid than other currently available assays and can be performed in any routine microbiology laboratory. This can help to rapidly identify patients with CPE BSI and optimize the management of patients with these difficult-to-treat infections. Further studies are needed to assess the performance of the ICT in routine diagnostics.

18.
Mycoses ; 61(11): 796-813, 2018 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-30098069

RESUMO

Invasive fungal diseases (IFD) are a primary cause of morbidity and mortality in patients with haematological malignancies. These infections are mostly life-threatening and an early diagnosis and initiation of appropriate antifungal therapy are essential for the clinical outcome. Most commonly, Aspergillus and Candida species are involved. However, other Non-Aspergillus moulds are increasingly identified in case of documented IFD. For definite diagnosis of IFD, a combination of diagnostic tools have to be applied, including conventional mycological culture and non-conventional microbiological tests such as antibody/antigen and molecular tests, as well as histopathology and radiology. Although varying widely in cancer patients, the risk of invasive fungal infection is highest in those with allogeneic stem cell transplantation and those with acute leukaemia and markedly lower in patients with solid cancer. Since the last edition of Diagnosis of Invasive Fungal Diseases recommendations of the German Society for Hematology and Oncology in 2012, integrated care pathways have been proposed for the management and therapy of IFDs with either a diagnostic driven strategy as opposed to a clinical or empirical driven strategy. This update discusses the impact of this additional evidence and effective revisions.

19.
BMC Genomics ; 19(1): 601, 2018 Aug 09.
Artigo em Inglês | MEDLINE | ID: mdl-30092762

RESUMO

BACKGROUND: Resistance to 3rd-generation cephalosporins in Escherichia coli is mostly mediated by extended-spectrum beta-lactamases (ESBLs) or AmpC beta-lactamases. Besides overexpression of the species-specific chromosomal ampC gene, acquisition of plasmid-encoded ampC genes, e.g. blaCMY-2, has been described worldwide in E. coli from humans and animals. To investigate a possible transmission of blaCMY-2 along the food production chain, we conducted a next-generation sequencing (NGS)-based analysis of 164 CMY-2-producing E. coli isolates from humans, livestock animals and foodstuff from Germany. RESULTS: The data of the 164 sequenced isolates revealed 59 different sequence types (STs); the most prevalent ones were ST38 (n = 19), ST131 (n = 16) and ST117 (n = 13). Two STs were present in all reservoirs: ST131 (human n = 8; food n = 2; animal n = 6) and ST38 (human n = 3; animal n = 9; food n = 7). All but one CMY-2-producing ST131 isolates belonged to the clade B (fimH22) that differed substantially from the worldwide dominant CTX-M-15-producing clonal lineage ST131-O25b clade C (fimH30). Plasmid replicon types IncI1 (n = 61) and IncK (n = 72) were identified for the majority of blaCMY-2-carrying plasmids. Plasmid sequence comparisons showed a remarkable sequence identity, especially for IncK plasmids. Associations of replicon types and distinct STs were shown for IncK and ST57, ST429 and ST38 as well as for IncI1 and ST58. Additional ß-lactamase genes (blaTEM, blaCTX-M, blaOXA, blaSHV) were detected in 50% of the isolates, and twelve E. coli from chicken and retail chicken meat carried the colistin resistance gene mcr-1. CONCLUSION: We found isolates of distinct E. coli clonal lineages (ST131 and ST38) in all three reservoirs. However, a direct clonal relationship of isolates from food animals and humans was only noticeable for a few cases. The CMY-2-producing E. coli-ST131 represents a clonal lineage different from the CTX-M-15-producing ST131-O25b cluster. Apart from the ST-driven spread, plasmid-mediated spread, especially via IncI1 and IncK plasmids, likely plays an important role for emergence and transmission of blaCMY-2 between animals and humans.


Assuntos
Infecções por Escherichia coli/veterinária , Escherichia coli/genética , Escherichia coli/isolamento & purificação , Análise de Alimentos/métodos , Sequenciamento Completo do Genoma/métodos , Animais , Bovinos , Galinhas , Escherichia coli/enzimologia , Escherichia coli/metabolismo , Infecções por Escherichia coli/microbiologia , Proteínas de Escherichia coli/genética , Proteínas de Escherichia coli/metabolismo , Alemanha , Filogenia , Polimorfismo de Nucleotídeo Único , Suínos , Perus , beta-Lactamases/genética , beta-Lactamases/metabolismo
20.
Eur J Clin Microbiol Infect Dis ; 37(10): 1857-1861, 2018 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-29980897

RESUMO

Methicillin-resistant Staphylococcus aureus (MRSA) is a major cause of healthcare-associated infections and mortality, and therefore constitutes a serious cost factor in public health. Culture-based MRSA screening is a crucial part of MRSA-infection prevention and control strategies in the hospital setting. Manual inoculation of screening swabs onto culture plates still constitutes the major part of the technicians' workload in laboratories. We present a modified inoculation protocol that comprises direct inoculation of specimen onto a chromogenic MRSA-selective agar plate without further streaking for isolation. This study aims to evaluate the impact of this inoculation protocol on technicians' workload and the downstream workflow in our laboratory. Batches of 50 specimens were processed by different technicians and the hands-on time was compared between the standard and modified inoculation protocol. To assess the impact on downstream processing, a retrospective analysis of the rate of subcultures and turnaround time (TAT) of specimens yielding putative MRSA colonies from 9 months before (n = 1548) and after (n = 1267) the protocol change was carried out based on laboratory information system (LIS) data. The implementation of the modified protocol significantly reduced technicians' hands-on time needed for inoculation by 26.5% without altering the overall turnaround time of surveillance cultures or causing higher costs for extra plates needed for subcultures. Our modified inoculation protocol offers a cost-effective and easy to implement procedure for MRSA surveillance cultures which significantly decreases technicians' workload and does not impede the downstream workflow. It therefore increases the capacity of laboratory technicians' to execute more demanding tasks.

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