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INTRODUCTION: Candida auris is an emerging pathogen in health care-associated infections. In contrast to many other countries with rising numbers of C. auris, only seven cases have been reported in Germany from 2015 to 2017, mostly from patients who received prior medical treatment abroad. We therefore established a mandatory screening for C. auris colonisation at our tertiary care centre for all patients who were admitted as international patients or previously hospitalised in a foreign country within the past 6 months. METHODS: Colonisation of patients was assessed using a previously established screening protocol for multidrug resistant bacteria. Since 2017, all screening samples were additionally analysed for C. auris using CHROMagar Candida (CHROMagar, Paris, France). Yeast isolates were identified using matrix-assisted laser ionisation time-of-flight (MALDI TOF), except for C. albicans (identified by the typical green colour on chromogenic agar). Data were analysed retrospectively. RESULTS: Our study cohort included 655 patients and an overall number of 1399 samples. Fifty-three patients were colonised with Candida species (C. albicans, n = 37; C. glabrata, n = 14; others n = 9). No case of C. auris was detected. Candida spp. were mainly detected from respiratory samples (5.4% positive) and gastrointestinal specimen (5.2%). Laboratory costs were 14,689 and analyses resulted in 98.7 h of additional technician's work. CONCLUSION: No colonisation with C. auris was detected among patients with previous hospitalisation abroad. Universal C. auris screening of patients with any contact to foreign health care does not seem to be cost-effective in our setting and more targeted screening strategies have to be developed.
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Antifúngicos , Turismo Médico , Humanos , Antifúngicos/uso terapêutico , Candida auris , Estudos Retrospectivos , Candida , Candida albicans , Candida glabrata , Hospitalização , Hospitais , Testes de Sensibilidade MicrobianaRESUMO
To determine viral dynamics in Omicron breakthrough infections, we measured severe acute respiratory syndrome coronavirus 2 RNA in 206 double-vaccinated or boostered individuals. During the first 3 days following the onset of symptoms, viral loads were significantly higher (cycle threshold [Ct], 21.76) in vaccinated compared to boostered (Ct, 23.14) individuals (P = .029). However, by performing a longitudinal analysis on 32 individuals over 14 days, no difference in the viral load trajectory was observed between double-vaccinated and boostered patients. Our results indicate that booster immunization results in a reduction in detectable viral loads without significantly changing viral load dynamics over time.
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COVID-19 , Humanos , SARS-CoV-2 , Carga Viral , Testes Sorológicos , Anticorpos AntiviraisRESUMO
BackgroundEvidence supporting the effectiveness of single-room contact precautions (SCP) in preventing in-hospital acquisition of vancomycin-resistant enterococci (haVRE) is limited.AimWe assessed the impact of SCP on haVRE and their transmission.MethodsWe conducted a prospective, multicentre cohort study in German haematological/oncological departments during 2016. Two sites performed SCP for VRE patients and two did not (NCP). We defined a 5% haVRE-risk difference as non-inferiority margin, screened patients for VRE, and characterised isolates by whole genome sequencing and core genome MLST (cgMLST). Potential confounders were assessed by competing risk regression analysis.ResultsWe included 1,397 patients at NCP and 1,531 patients at SCP sites. Not performing SCP was associated with a significantly higher proportion of haVRE; 12.2% (170/1,397) patients at NCP and 7.4% (113/1,531) patients at SCP sites (relative risk (RR) 1.74; 95% confidence interval (CI): 1.35-2.23). The difference (4.8%) was below the non-inferiority margin. Competing risk regression analysis indicated a stronger impact of antimicrobial exposure (subdistribution hazard ratio (SHR) 7.46; 95% CI: 4.59-12.12) and underlying disease (SHR for acute leukaemia 2.34; 95% CI: 1.46-3.75) on haVRE than NCP (SHR 1.60; 95% CI: 1.14-2.25). Based on cgMLST and patient movement data, we observed 131 patient-to-patient VRE transmissions at NCP and 85 at SCP sites (RR 1.76; 95% CI: 1.33-2.34).ConclusionsWe show a positive impact of SCP on haVRE in a high-risk population, although the observed difference was below the pre-specified non-inferiority margin. Importantly, other factors including antimicrobial exposure seem to be more influential.
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Infecção Hospitalar , Infecções por Bactérias Gram-Positivas , Enterococos Resistentes à Vancomicina , Estudos de Coortes , Infecção Hospitalar/epidemiologia , Infecção Hospitalar/prevenção & controle , Infecções por Bactérias Gram-Positivas/epidemiologia , Infecções por Bactérias Gram-Positivas/prevenção & controle , Humanos , Tipagem de Sequências Multilocus , Estudos Prospectivos , Enterococos Resistentes à Vancomicina/genéticaRESUMO
OBJECTIVES: To characterize two Enterococcus faecium isolates with different resistance phenotypes obtained from the same blood culture. METHODS: The isolates were identified by MALDI-TOF MS and antimicrobial susceptibility testing (AST) was performed using a VITEK® 2 AST P592 card and Etest. WGS was performed on the MiSeq and MinION sequencer platforms. Core-genome MLST (cgMLST) and seven-loci MLST were performed. Plasmid analysis was performed using S1-PFGE followed by Southern-blot hybridization. RESULTS: Both E. faecium isolates were ST203. AST revealed that one was a vancomycin-resistant E. faecium (VREfm) isolate and the other was a vancomycin-susceptible E. faecium (VSEfm) isolate. The VREfm isolate harboured the vanA gene cluster as part of a Tn1546-type transposon encoded on a 49 kb multireplicon (rep1, rep2 and rep7a) plasmid (pAML0157.1). On the same plasmid, ant(6)-Ia, cat-like and erm(B) were encoded. The VSEfm isolate harboured a rep2 plasmid (pAML0158.1), 12 kb in size, which was present in full length as part of pAML0157.1 from the VREfm isolate. The vanA-encoding pAML0157.1 was a chimera of the rep2 pAML0158.1 and a second DNA segment harbouring vanA, ant(6)-Ia, erm(B) and cat-like, as well as the replicons rep1 and rep7a. By cgMLST analysis, the VREfm and VSEfm isolates were identical. CONCLUSIONS: Our results demonstrate that the VREfm and VSEfm blood culture isolates represented ST203 and were identical. The investigated heterogeneous resistance phenotypes resulted from the acquisition or loss of plasmid segments in the enterococcal isolates. These data illustrate that mobile genetic elements may contribute to the spread of vancomycin resistance among enterococci and to the genotypic and phenotypic variation within clonal isolates.
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Enterococcus faecium , Infecções por Bactérias Gram-Positivas , Enterococos Resistentes à Vancomicina , Proteínas de Bactérias/genética , Hemocultura , Enterococcus faecium/genética , Humanos , Tipagem de Sequências Multilocus , Vancomicina/farmacologia , Enterococos Resistentes à Vancomicina/genéticaRESUMO
OBJECTIVES: To assess the admission prevalence of third-generation cephalosporin-resistant Enterobacterales (3GCREB) and to assess whether risk factors vary by ß-lactamase genotype. METHODS: Adult patients were recruited within 72 h of admission to general wards of six university hospitals in 2014 and 2015. Rectal swabs were screened for 3GCREB and isolates were analysed phenotypically and genotypically. Patients were questioned on potential risk factors. Multivariable analyses were performed to identify risk factors for 3GCREB colonization and for specific ß-lactamases. RESULTS: Of 8753 patients screened, 828 were 3GCREB positive (9.5%). Eight hundred and thirteen isolates were available for genotyping. CTX-M-15 was the most common ESBL (38.0%), followed by CTX-M-1 (22.5%), CTX-M-14 (8.7%), CTX-M-27 (7.5%) and SHV-ESBL (4.4%). AmpC was found in 11.9%. Interestingly, 18 Escherichia coli isolates were AmpC positive, 12 of which (67%) contained AmpC on a gene of plasmid origin [CMY (n = 10), DHA (n = 2)]. Risk factors for 3GCREB colonization varied by genotype. Recent antibiotic exposure and prior colonization by antibiotic-resistant bacteria were risk factors for all ß-lactamases except CTX-M-14 and CTX-M-27. Travel outside Europe was a risk factor for CTX-M-15 and CTX-M-27 [adjusted OR (aOR) 3.49, 95% CI 2.88-4.24 and aOR 2.73, 95% CI 1.68-4.43]. A previous stay in a long-term care facility was associated with CTX-M-14 (aOR 3.01, 95% CI 1.98-4.59). A preceding hospital stay in Germany increased the risk of CTX-M-15 (aOR 1.27, 95% CI 1.14-1.41), while a prior hospital stay in other European countries increased the risk of SHV-ESBL colonization (aOR 3.85, 95% CI 1.67-8.92). CONCLUSIONS: The detection of different ESBL types is associated with specific risk factor sets that might represent distinct sources of colonization and ESBL-specific dissemination routes.
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Infecções por Escherichia coli , beta-Lactamases , Adulto , Cefalosporinas/farmacologia , Estudos Transversais , Infecções por Escherichia coli/epidemiologia , Europa (Continente) , Genótipo , Alemanha/epidemiologia , Hospitais Universitários , Humanos , Prevalência , beta-Lactamases/genéticaRESUMO
Although Moraxella catarrhalis and Neisseria meningitidis are important human pathogens, they often colonize the human respiratory tract without causing overt clinical symptoms. Both pathogens express structurally unrelated proteins that share the ability to stimulate the adhesion molecule CEACAM1 expressed on human cells. Here we demonstrate that the interaction of CEACAM1 with ubiquitous surface protein A1 expressed on M. catarrhalis or with opacity-associated proteins on N. meningitidis resulted in reduced Toll-like receptor 2-initiated transcription factor NF-kappaB-dependent inflammatory responses of primary pulmonary epithelial cells. These inhibitory effects were mediated by tyrosine phosphorylation of the immunoreceptor tyrosine-based inhibitory motif of CEACAM1 and by recruitment of the phosphatase SHP-1, which negatively regulated Toll-like receptor 2-dependent activation of the phosphatidylinositol 3-OH kinase-Akt kinase pathway. Our results identify a CEACAM1-dependent immune-evasion strategy.
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Antígenos CD/imunologia , Brônquios/imunologia , Moléculas de Adesão Celular/imunologia , Moraxella catarrhalis/imunologia , Neisseria meningitidis/imunologia , Mucosa Respiratória/imunologia , Receptor 2 Toll-Like/imunologia , Motivos de Aminoácidos/fisiologia , Antígenos de Bactérias/imunologia , Antígenos de Bactérias/metabolismo , Antígenos CD/química , Proteínas da Membrana Bacteriana Externa/imunologia , Proteínas da Membrana Bacteriana Externa/metabolismo , Brônquios/metabolismo , Brônquios/microbiologia , Moléculas de Adesão Celular/química , Células Cultivadas , Citocinas/metabolismo , Regulação para Baixo , Humanos , NF-kappa B/antagonistas & inibidores , NF-kappa B/metabolismo , Fosfatidilinositol 3-Quinases/metabolismo , Proteína Tirosina Fosfatase não Receptora Tipo 6/metabolismo , Proteínas Proto-Oncogênicas c-akt/metabolismo , Mucosa Respiratória/metabolismo , Mucosa Respiratória/microbiologia , Transdução de Sinais/imunologia , Receptor 2 Toll-Like/metabolismoRESUMO
The coronavirus disease (COVID-19) pandemic has caused tremendous pressure on hospital infrastructures such as emergency rooms (ER) and outpatient departments. To avoid malfunctioning of critical services because of large numbers of potentially infected patients seeking consultation, we established a COVID-19 rapid response infrastructure (CRRI), which instantly restored ER functionality. The CRRI was also used for testing of hospital personnel, provided epidemiological data and was a highly effective response to increasing numbers of suspected COVID-19 cases.
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Defesa Civil/organização & administração , Infecções por Coronavirus/epidemiologia , Coronavirus , Surtos de Doenças , Administração dos Cuidados ao Paciente , Pneumonia Viral/epidemiologia , Adulto , Betacoronavirus , COVID-19 , Alemanha/epidemiologia , Humanos , Pessoa de Meia-Idade , Pandemias , Medição de Risco , SARS-CoV-2 , Centros de Atenção Terciária , TriagemRESUMO
OBJECTIVES: Clostridioides difficile infection (CDI) is one of the most important healthcare-associated infections. We aimed to describe the incidence density of healthcare-associated CDI (HA-CDI) in Germany's largest hospital and to identify associations with ward-level antimicrobial consumption. METHODS: We used surveillance data on CDI and antimicrobial consumption from 2014 to 2017 and analysed a potential association by means of multivariable regression analysis. RESULTS: We included 77 wards with 404998 admitted patients and 1850862 patient-days. Six hundred and seventy-one HA-CDI cases were identified, resulting in a pooled mean incidence density of 0.36/1000 patient-days (IQR = 0.34-0.39). HA-CDI incidence density on ICU and haematological-oncological wards was about three times higher than on surgical wards [incidence rate ratio (IRR) = 3.00 (95% CI = 1.96-4.60) and IRR = 2.78 (95% CI = 1.88-4.11), respectively]. Ward-level consumption of third-generation cephalosporins was the sole antimicrobial risk factor for HA-CDI. With each DDD/100 patient-days administered, a ward's HA-CDI incidence density increased by 2% [IRR = 1.02 (95% CI = 1.01-1.04)]. Other risk factors were contemporaneous community-associated CDI cases [IRR = 1.32 (95% CI = 1.07-1.63)] and CDI cases in the previous month [IRR = 1.27 (95% CI = 1.07-1.51)]. Furthermore, we found a significant decrease in HA-CDI in 2017 compared with 2014 [IRR = 0.68 (95% CI = 0.54-0.86)]. CONCLUSIONS: We confirmed that ward-level antimicrobial use influences HA-CDI and specifically identified third-generation cephalosporin consumption as a risk factor.
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Antibacterianos/uso terapêutico , Infecções por Clostridium/epidemiologia , Infecção Hospitalar/epidemiologia , Uso de Medicamentos/estatística & dados numéricos , Antibacterianos/efeitos adversos , Alemanha/epidemiologia , Hospitais Universitários , Humanos , Incidência , Fatores de RiscoAssuntos
Mpox , Exposição Ocupacional , Humanos , Monkeypox virus/genética , Mpox/epidemiologia , DNA Viral , Pessoal de SaúdeRESUMO
Objectives: Fluoroquinolone resistance (FQR) in third-generation cephalosporin-resistant Enterobacteriaceae (3GCRE) presents serious limitations to antibiotic therapy. The aim of this study was to investigate whether the FQR proportion among 3GCRE differs between community-acquired (CA) and hospital-acquired (HA) isolates. Methods: In a prospective observational study covering 2014 and 2015, we monitored the occurrence of 3GCRE in adult hospitalized patients in six German university hospitals. 3GCRE clinical isolates were subdivided into CA and HA. Multivariable analysis identified factors associated with in vitro non-susceptibility to ciprofloxacin. Results: The dataset included 5721 3GCRE isolates of which 52.9% were HA and 52.7% exhibited FQR. Interestingly, the FQR proportion was higher in CA 3GCRE than in HA 3GCRE (overall, 60.1% versus 46.2%, respectively, P < 0.001). Multivariable analysis adjusting for age confirmed community acquisition as a risk factor for FQR [adjusted rate ratio (aRR) 1.33, 95% CI 1.17-1.53]. Escherichia coli and Klebsiella spp. were associated with a much higher FQR proportion than other Enterobacteriaceae species (aRR 8.14, 95% CI 6.86-9.65 and aRR 7.62 with 95% CI 6.74-8.61, respectively). Conclusions: The high FQR proportion observed among CA 3GCRE, particularly in E. coli and Klebsiella spp., indicates that selection pressure in the outpatient setting needs to be addressed with antibiotic stewardship and other interventions in order to limit further spread of MDR.
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Antibacterianos/farmacologia , Cefalosporinas/farmacologia , Farmacorresistência Bacteriana Múltipla , Infecções por Enterobacteriaceae/epidemiologia , Enterobacteriaceae/efeitos dos fármacos , Fluoroquinolonas/farmacocinética , Adulto , Idoso , Infecção Hospitalar/epidemiologia , Infecção Hospitalar/microbiologia , Enterobacteriaceae/isolamento & purificação , Infecções por Enterobacteriaceae/microbiologia , Escherichia coli/efeitos dos fármacos , Feminino , Alemanha/epidemiologia , Hospitalização , Hospitais Universitários , Humanos , Klebsiella/efeitos dos fármacos , Masculino , Testes de Sensibilidade Microbiana , Pessoa de Meia-Idade , Prevalência , Estudos ProspectivosRESUMO
BACKGROUND: Bacterial colonisation with Moraxella catarrhalis may partly sustain chronic inflammation in the lower airways of patients with chronic obstructive pulmonary disease (COPD). In addition, this bacterium causes infectious exacerbations of COPD, which often necessitate treatment with antibiotics. Antimicrobial peptides are the body's own antibiotic substances with bactericidal and bacteriostatic, as well as immunomodulatory function. In particular, human beta-defensin 3 (hBD-3) exerts an antimicrobial effect against an extraordinarily broad spectrum of pathogens. We therefore investigated the role of hBD-3 in infections of pulmonary epithelial cells with M. catarrhalis. METHODS: The antimicrobial activity of hBD-3 vs. M. catarrhalis was evaluated in an antimicrobial susceptibility assay. We analyzed hBD-3 secretion of M. catarrhalis-infected pulmonary epithelial cells using ELISA. The role of M. catarrhalis-specific virulence factors, toll-like receptors (TLR) 2 and 4, MAPK pathways, and transcription factors AP-1 and NF-κB in the induction and regulation of hBD-3 expression were explored with specific inhibitors, small interference RNA, Western Blot, and chromatin immunoprecipitation (ChIP) assays. RESULTS: HBD-3 exhibited a strong bactericidal effect against M. catarrhalis. M. catarrhalis induced hBD-3 expression in pulmonary epithelial cells, which was dependent on M. catarrhalis membranous lipoolygosaccharide (LOS), while the surface proteins UspA1 and UspA2 were not involved. Gene silencing of TLR2, but not TLR4, led to a reduced hBD-3 secretion after stimulation with M. catarrhalis or M. catarrhalis LOS. Inhibition of MAPKs ERK1/2 and JNK, but not p38, reduced hBD-3 secretion. HBD-3 expression was mediated through the recruitment of AP-1 to the hBD-3 gene promoter and was independent of NF-κB. CONCLUSION: The immune response of pulmonary epithelial cells towards M. catarrhalis involves secretion of hBD-3, which has a bactericidal effect against this pathogen. Binding of M. catarrhalis virulence factor LOS to TLR2 causes an ERK1/2- and JNK-dependent induction of AP-1-related transcription of the hBD-3 gene, resulting in the production and secretion of hBD-3.
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Moraxella catarrhalis/patogenicidade , Mucosa Respiratória/metabolismo , Mucosa Respiratória/microbiologia , beta-Defensinas/metabolismo , Linhagem Celular , Células Epiteliais/imunologia , Células Epiteliais/metabolismo , Células Epiteliais/microbiologia , Regulação da Expressão Gênica , Humanos , Lipopolissacarídeos/imunologia , Pulmão/imunologia , Pulmão/metabolismo , Pulmão/microbiologia , Sistema de Sinalização das MAP Quinases , Moraxella catarrhalis/imunologia , Infecções por Moraxellaceae/complicações , NF-kappa B/metabolismo , Doença Pulmonar Obstrutiva Crônica/etiologia , Doença Pulmonar Obstrutiva Crônica/metabolismo , Doença Pulmonar Obstrutiva Crônica/microbiologia , Mucosa Respiratória/imunologia , Receptor 2 Toll-Like/metabolismo , Receptor 4 Toll-Like/metabolismo , Fator de Transcrição AP-1/metabolismo , beta-Defensinas/genéticaRESUMO
The widespread dissemination of carbapenem-resistant bacteria in wastewater systems, particularly from clinical sources, poses a significant public health risk. This study assessed the concentrations and distributions of extracellular DNA (exDNA) and intracellular DNA (iDNA) harboring carbapenemase genes in wastewater from six tertiary care hospitals in Germany. We collected a total of 36 samples, comprising six biological replicates from each hospital, and analysed them using quantitative real-time PCR (qPCR) and digital PCR (dPCR). The analysis targeted seven carbapenemase genes: blaNDM, blaKPC, blaIMP, blaVIM, blaOXA-23-like, blaOXA-48-like, and blaOXA-58-like across both DNA fractions. Our results revealed significant variability in the concentrations of exDNA and iDNA across the sampling sites, with iDNA typically present at higher concentrations. Using NanoDrop One spectrophotometry and the Qubit dsDNA kit, exDNA concentrations ranged from 2.7 to 7.7â¯ng/mL, while Qubit recorded lower values between 1.1 and 4.0â¯ng/mL. Conversely, iDNA concentrations were markedly higher, spanning from 42.3 to 191.7â¯ng/mL with NanoDrop and 12.0 to 46.5â¯ng/mL with Qubit, highlighting the variability between DNA types and quantification methods. Despite its lower concentrations, exDNA comprised up to 18.2â¯% of total DNA, highlighting its potential role in the horizontal transfer of antimicrobial resistance genes (ARGs). The study detected target ARGs in both DNA fractions at all sites, with notable differences in their concentrations; iDNA consistently exhibited higher levels of ARGs, with the highest concentrations reaching 10.57⯱â¯0.20 log gene copies per liter (GC/L) for blaVIM in iDNA and 6.96⯱â¯0.72 log GC/L for blaIMP in exDNA. dPCR demonstrated greater sensitivity than qPCR, especially effective for detecting low-abundance targets like blaOXA-23-like in the exDNA fraction. Additionally, qPCR's susceptibility to inhibition and contamination emphasizes the superior robustness of dPCR. This research highlights the need for improved monitoring and the implementation of advanced treatment technologies to mitigate ARG dissemination in wastewater.
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OBJECTIVES: Assessment of vancomycin-resistant Enterococcus faecium (VREfm) prevalence upon hospital admission and analysis of risk factors for colonization. METHODS: From 2014 to 2018, patients were recruited within 72 hours of admission to seven participating German university hospitals, screened for VREfm and questioned for potential risk factors (prior multidrug-resistant organism detection, current/prior antibiotic consumption, prior hospital, rehabilitation or long-term care facility stay, international travel, animal contact and proton pump inhibitor [PPI]/antacid therapy). Genotype analysis was done using cgMLST typing. Multivariable analysis was performed. RESULTS: In 5 years, 265 of 17,349 included patients were colonized with VREfm (a prevalence of 1.5%). Risk factors for VREfm colonization were age (adjusted OR [aOR], 1.02; 95% CI, 1.01-1.03), previous (aOR, 2.71; 95% CI, 1.87-3.92) or current (aOR, 2.91; 95% CI, 2.60-3.24) antibiotic treatment, prior multidrug-resistant organism detection (aOR, 2.83; 95% CI, 2.21-3.63), prior stay in a long-term care facility (aOR, 2.19; 95% CI, 1.62-2.97), prior stay in a hospital (aOR, 2.91; 95% CI, 2.05-4.13) and prior consumption of PPI/antacids (aOR, 1.29; 95% CI, 1.18-1.41). Overall, the VREfm admission prevalence increased by 33% each year and 2% each year of life. 250 of 265 isolates were genotyped and 141 (53.2%) of the VREfm were the emerging ST117. Multivariable analysis showed that ST117 and non-ST117 VREfm colonized patients differed with respect to admission year and prior multidrug-resistant organism detection. DISCUSSION: Age, healthcare contacts and antibiotic and PPI/antacid consumption increase the individual risk of VREfm colonization. The VREfm admission prevalence increase in Germany is mainly driven by the emergence of ST117.
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Infecção Hospitalar , Enterococcus faecium , Infecções por Bactérias Gram-Positivas , Enterococos Resistentes à Vancomicina , Animais , Vancomicina/farmacologia , Hospitais Universitários , Estudos Transversais , Prevalência , Antiácidos , Antibacterianos/farmacologia , Fatores de Risco , Infecções por Bactérias Gram-Positivas/epidemiologia , Infecções por Bactérias Gram-Positivas/microbiologia , Infecção Hospitalar/epidemiologia , Infecção Hospitalar/microbiologiaRESUMO
Species within the Enterobacter cloacae complex (ECC) include globally important nosocomial pathogens. A three-year study of ECC in Germany identified Enterobacter xiangfangensis as the most common species (65.5%) detected, a result replicated by examining a global pool of 3246 isolates. Antibiotic resistance profiling revealed widespread resistance and heteroresistance to the antibiotic colistin and detected the mobile colistin resistance (mcr)-9 gene in 19.2% of all isolates. We show that resistance and heteroresistance properties depend on the chromosomal arnBCADTEF gene cassette whose products catalyze transfer of L-Ara4N to lipid A. Using comparative genomics, mutational analysis, and quantitative lipid A profiling we demonstrate that intrinsic lipid A modification levels are genospecies-dependent and governed by allelic variations in phoPQ and mgrB, that encode a two-component sensor-activator system and specific inhibitor peptide. By generating phoPQ chimeras and combining them with mgrB alleles, we show that interactions at the pH-sensing interface of the sensory histidine kinase phoQ dictate arnBCADTEF expression levels. To minimize therapeutic failures, we developed an assay that accurately detects colistin resistance levels for any ECC isolate.
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Colistina , Lipídeo A , Colistina/farmacologia , Colistina/uso terapêutico , Lipídeo A/química , Lipídeo A/farmacologia , Proteínas de Bactérias/metabolismo , Antibacterianos/farmacologia , Antibacterianos/uso terapêutico , Enterobacter/genética , Farmacorresistência Bacteriana/genética , Testes de Sensibilidade MicrobianaRESUMO
Studying the interaction of dendritic cells (DCs) with bacteria controlled by T-cell-mediated immune responses may reveal novel adjuvants for the induction of cellular immunity. Murine studies and the observation that nocardias infect predominantly immunosuppressed patients have suggested that these bacteria may possess an adjuvant potential. Moreover, adjuvants on the basis of the nocardial cell wall have been applied in clinical studies. Since the handling of adjuvants by DCs may determine the type of immune responses induced by a vaccine, the present study aimed at investigating the interaction of immature human monocyte-derived DCs with live or inactivated Nocardia farcinica in vitro and determining the cellular phenotypic changes as well as alterations in characteristic functions, such as phagocytosis, induction of T-cell proliferation, and cytokine secretion. Human DCs ingested N. farcinica and eradicated the bacterium intracellularly. DCs exposed to inactivated N. farcinica were activated, i.e., they developed a mature phenotype, downregulated their phagocytic capacity, and stimulated allogeneic T cells in mixed leukocyte reactions. Soluble factors were not involved in this process. To elucidate the potential adjuvant effect of N. farcinica on the induction of T-cell-mediated immune responses, we characterized the cytokines produced by nocardia-exposed DCs and detected substantial amounts of tumor necrosis factor alpha (TNF-α) and interleukin-12 p40 (IL-12p40). However, nocardia-treated DCs secreted only small amounts of IL-12p70, which were significantly smaller than the amounts of IL-23. Thus, N. farcinica activates DCs, but adjuvants based on this bacterium may have only a limited capacity to induce Th1 immune responses.
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Células Dendríticas/imunologia , Interleucina-12/biossíntese , Interleucina-23/biossíntese , Nocardia/imunologia , Adjuvantes Imunológicos , Células Dendríticas/metabolismo , Humanos , Subunidade p40 da Interleucina-12/imunologia , Ativação Linfocitária , Teste de Cultura Mista de Linfócitos , Nocardia/classificação , Linfócitos T/imunologiaRESUMO
BACKGROUND: Extreme immature infants are at an increased risk of fungal infection due to immaturity of the skin barrier and the immune system. Besides Candida infections, in particular, Aspergillus may cause life-threatening diseases in preterm infants. Frequently, Aspergillus primarily affects the skin and may cause extensive damage. METHODS: We searched our hospital database for fungal infections other than Candida in preterm infants treated between 2015 and 2020 at our level III neonatal intensive care unit of the University Hospital of Cologne. RESULTS: In total, 13 preterm infants were identified. Of these, 11 had cutaneous Aspergillosis, one infant had severe enterocolitis caused by Aspergillus and Rhizopus and one had invasive intraabdominal Trichosporon mucoides infection. All infants were born <24 weeks of gestation, were delivered due to premature labor or chorioamnionitis, and had received prenatal steroids and/or hydrocortisone. Voriconazole and liposomal Amphotericin B were first-line treatments and the length of treatment varied between 3 and 148 days. Two infants died associated with severe infection. Liver toxicity was observed in six infants treated with Voriconazole. Therapeutic drug management for Voriconazole was performed in four infants. Target levels were not achieved by the doses that are recommended. CONCLUSIONS: Rare fungal infections, predominantly cutaneous Aspergillosis affects the most immature preterm infants and may cause severe disease. Treatment with Voriconazole has a high rate of liver toxicity and target levels are difficult to achieve in extremely immature infants.
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Aspergilose , Doenças do Prematuro , Micoses , Antifúngicos/uso terapêutico , Aspergilose/tratamento farmacológico , Aspergilose/epidemiologia , Feminino , Fungos , Humanos , Lactente , Lactente Extremamente Prematuro , Recém-Nascido , Doenças do Prematuro/tratamento farmacológico , Doenças do Prematuro/epidemiologia , Micoses/tratamento farmacológico , Micoses/epidemiologia , Gravidez , Voriconazol/uso terapêuticoRESUMO
Background: Hospital-acquired infections due to vancomycin-resistant enterococci (VRE) are emerging globally. The aims of our study were to estimate VRE colonisation prevalence in patients upon admission, to determine possible risk factors for VR E. faecium acquisition that already exist in the outpatient setting, and to monitor whether VRE-colonised patients developed a VRE infection during their current hospital stay. Methods: In 2014 and 2015, patients admitted to non-intensive care units were screened for rectal VRE carriage. The study patients filled out a questionnaire on potential risk factors. Analyses were restricted to VR E. faecium carriage. All patients with VRE colonisation were retrospectively monitored for infections with VRE during their current hospital stay. Results: In 4,013 enrolled patients, the VRE colonisation prevalence upon admission was 1.2% (n=48), and colonisation prevalence was 1.1% (n=45) for VR E. faecium. Only one VRE-colonised patient developed an infection with the detection of a VRE, among others. Colonisation with VR E. faecium was associated with current antibiotic use. Risk factors of VR E. faecium colonisation upon admission were increasing age, previous colonisation or infection with multidrug resistant organisms, sampling year 2015, and, within the previous six months, antibiotic exposure, a stay at a rehabilitation center, and a hospital stay. Conclusions: We observed that antibiotic treatment which occurred prior admission influenced VR E. faecium prevalence upon admission. Thus, wise antibiotic use in outpatient settings plays a major role in the prevention of VR E. faecium acquisition.
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Streptococcus pneumoniae is the most common cause of bacterial meningitis of high mortality and morbidity. Neurological sequelae include paralysis, mental retardation, and learning disorders. In humans, neurons of the hippocampus undergo apoptosis as a result of meningitis. Phosphatidylcholine (PtdCho) is an essential component of mammalian cell membranes and PtdCho deficiency, either due to chemicals or altered nutrition, leads to apoptosis, especially in hippocampal neurons. We show that apoptosis of a variety of brain cells after pneumococcal infection arises from inhibition of PtdCho biosynthesis, the first such activity described for a bacterium. Apoptosis inhibitors did not prevent the bacterial-dependent inhibition of PtdCho biosynthesis. Supplementation with exogenous lyso-phosphatidylcholine prevents cell death and treatment of mice with cytidine diphosphocholine attenuates hippocampal damage during meningitis, even after the onset of infection. We conclude that bacterial inhibition of PtdCho biosynthesis activates an apoptotic cascade that is a causative event in pathogenesis and amenable to therapeutic intervention.
Assuntos
Apoptose/fisiologia , Hipocampo/metabolismo , Fosfatidilcolinas/biossíntese , Streptococcus pneumoniae/metabolismo , Animais , Linhagem Celular , Citidina Difosfato Colina/metabolismo , Hipocampo/citologia , Humanos , Lisofosfatidilcolinas/metabolismo , Camundongos , Microglia/citologia , Microglia/metabolismo , Neurônios/citologia , Neurônios/metabolismo , Nootrópicos/metabolismo , Infecções Pneumocócicas/metabolismo , RatosRESUMO
Introduction. Transmission of Enterobacterales in neonatal intensive care units (NICU) can cause outbreaks of colonization and invasive infections among neonates. Two clusters of nosocomial transmission of Klebsiella pneumoniae identified by MALDI-ToF mass-spectrometry were suspected at two NICUs in July and August 2016.Aim. To assess the potential transmission of K. pneumoniae among neonates.Methodology. Whole-genome sequencing (WGS) was performed of K. pneumoniae isolates obtained through targeted surveillance of patients and environmental sampling.Results. WGS data revealed that patient and environmental isolates represented two species, K. pneumoniae and K. variicola. Core-genome multi-locus sequence typing (cgMLST) of the isolates identified three separate transmission clusters, in Hospital A a cluster of K. pneumoniae isolates in 12 children and two environmental samples and a second cluster of K. variicola isolates in five children. In Hospital B a cluster of K. pneumoniae isolates from three children and five unrelated isolates of K. pneumoniae and two unrelated isolates of K. variicola were found.Conclusion. K. variicola can cause hospital outbreaks of colonization and infection similar to other Klebsiella spp.Preliminary results from this study were presented at the 27th European Congress of Clinical Microbiology and Infectious Diseases, April 22-25, 2018, Vienna, Austria.
Assuntos
Infecção Hospitalar , Surtos de Doenças , Genoma Bacteriano/genética , Infecções por Klebsiella/epidemiologia , Klebsiella pneumoniae/genética , Klebsiella/genética , Técnicas de Tipagem Bacteriana , Alemanha/epidemiologia , Humanos , Recém-Nascido , Unidades de Terapia Intensiva Neonatal , Klebsiella/efeitos dos fármacos , Klebsiella/isolamento & purificação , Infecções por Klebsiella/microbiologia , Infecções por Klebsiella/transmissão , Klebsiella pneumoniae/efeitos dos fármacos , Klebsiella pneumoniae/isolamento & purificação , Tipagem de Sequências Multilocus , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz , Sequenciamento Completo do GenomaRESUMO
Aim: The consequences of antibiotic overuse are substantial. We combined and analyzed the infection diagnoses and antibiotic prescribing practices of physicians in outpatient settings. Recommendations for targeting policy efforts to focused areas are given. Methods: Antibiotic prescriptions and infections diagnosed were provided by a German statutory health insurance provider over a 12-month period. Antibiotic use was expressed as prescriptions per 100 patients. Results: 2,594,000 patient-physician contacts within twelve months were analyzed. A median of 6.5 antibiotics was prescribed to 100 patients. Antibiotic use in private practice showed large variations between and within medical specialties (the upper quarter of physicians who prescribed above the 75th percentile of all prescriptions, at a rate of approximately 43%), by season (antibiotic prescription was 50% higher in winter than in summer) and a considerable proportion of the antibiotics prescribed did not conform with the recommendations of national guidelines. Fluoroquinolones, predominantly ciprofloxacin, were among the top three antibiotics prescribed by all physicians (except pediatricians), although national guidelines do not recommend these agents for uncomplicated respiratory or urinary tract infections. Respiratory tract infections headed the list for the prescription of antibiotics. Conclusions: Antibiotics were still not prescribed appropriately in respect to indication and selection (often unnecessary and/or too broad). We recommend focusing on I) high/over-prescribers, because improved and appropriate antibiotic prescription by this group would result in an over-proportionally lower antibiotic prescription rate, II) respiratory tract infections, because they represent the vast majority of infections treated in primary care and III) intelligent implementation strategies of guidelines.