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1.
J Hosp Infect ; 147: 123-132, 2024 Mar 11.
Artigo em Inglês | MEDLINE | ID: mdl-38467251

RESUMO

BACKGROUND: Surgical site infections (SSIs), mainly caused by Staphylococcus aureus, pose a significant economic burden in Europe, leading to increased hospitalization duration, mortality, and treatment costs, particularly with drug-resistant strains such as meticillin-resistant S. aureus. AIM: To conduct a case-control study on the economic impact of S. aureus SSI in adult surgical patients across high-volume centres in France, Germany, Spain, and the UK, aiming to assess the overall and procedure-specific burden across Europe. METHODS: The SALT study is a multinational, retrospective cohort study with a nested case-control analysis focused on S. aureus SSI in Europe. The study included participants from France, Germany, Italy, Spain, and the UK who underwent invasive surgery in 2016 and employed a micro-costing approach to evaluate health economic factors, matching S. aureus SSI cases with controls. FINDINGS: In 2016, among 178,904 surgical patients in five European countries, 764 developed S. aureus SSI. Matching 744 cases to controls, the study revealed that S. aureus SSI cases incurred higher immediate hospitalization costs (€8,810), compared to controls (€6,032). Additionally, S. aureus SSI cases exhibited increased costs for readmissions within the first year post surgery (€7,961.6 versus €5,298.6), with significant differences observed. Factors associated with increased surgery-related costs included the cost of hospitalization immediately after surgery, first intensive care unit (ICU) admission within 12 months, and hospital readmission within 12 months, as identified through multivariable analysis. CONCLUSION: The higher rates of hospitalization, ICU admissions, and readmissions among S. aureus SSI cases highlight the severity of these infections and their impact on healthcare costs, emphasizing the potential benefits of evidence-based infection control measures and improved patient care to mitigate the economic burden.

2.
mBio ; 15(2): e0302523, 2024 Feb 14.
Artigo em Inglês | MEDLINE | ID: mdl-38126782

RESUMO

Clustered regularly interspaced short palindromic repeats (CRISPR) are prokaryotic adaptive immune systems regularly utilized as DNA-editing tools. While Neisseria gonorrhoeae does not have an endogenous CRISPR, the commensal species Neisseria lactamica encodes a functional Type I-C CRISPR-Cas system. We have established an isopropyl ß-d-1-thiogalactopyranoside added (IPTG)-inducible, CRISPR interference (CRISPRi) platform based on the N. lactamica Type I-C CRISPR missing the Cas3 nuclease to allow locus-specific transcriptional repression. As proof of principle, we targeted a non-phase-variable version of the opaD gene. We show that CRISPRi can downregulate opaD gene and protein expression, resulting in bacterial inability to stimulate neutrophil oxidative responses and to bind to an N-terminal fragment of CEACAM1. Importantly, we used CRISPRi to effectively knockdown all the transcripts of all 11 opa genes using a five-spacer CRISPR array, allowing control of the entire phase-variable opa family in strain FA1090. We also report that repression is reversible following IPTG removal. Finally, we showed that the Type I-C CRISPRi system can conditionally reduce the expression of two essential genes. This CRISPRi system will allow the interrogation of every Gc gene, essential and non-essential, to study physiology and pathogenesis and aid in antimicrobial development.IMPORTANCEClustered regularly interspaced short palindromic repeats (CRISPR)-Cas systems have proven instrumental in genetically manipulating many eukaryotic and prokaryotic organisms. Despite its usefulness, a CRISPR system had yet to be developed for use in Neisseria gonorrhoeae (Gc), a bacterium that is the main etiological agent of gonorrhea infection. Here, we developed a programmable and IPTG-inducible Type I-C CRISPR interference (CRISPRi) system derived from the commensal species Neisseria lactamica as a gene repression system in Gc. As opposed to generating genetic knockouts, the Type I-C CRISPRi system allows us to block transcription of specific genes without generating deletions in the DNA. We explored the properties of this system and found that a minimal spacer array is sufficient for gene repression while also facilitating efficient spacer reprogramming. Importantly, we also show that we can use CRISPRi to knockdown genes that are essential to Gc that cannot normally be knocked out under laboratory settings. Gc encodes ~800 essential genes, many of which have no predicted function. We predict that this Type I-C CRISPRi system can be used to help categorize gene functions and perhaps contribute to the development of novel therapeutics for gonorrhea.


Assuntos
Sistemas CRISPR-Cas , Gonorreia , Humanos , Neisseria gonorrhoeae/genética , Isopropiltiogalactosídeo , DNA
3.
PLoS Pathog ; 18(6): e1010561, 2022 06.
Artigo em Inglês | MEDLINE | ID: mdl-35714158

RESUMO

The Neisseria gonorrhoeae Type IV pilus is a multifunctional, dynamic fiber involved in host cell attachment, DNA transformation, and twitching motility. We previously reported that the N. gonorrhoeae pilus is also required for resistance against hydrogen peroxide-, antimicrobial peptide LL-37-, and non-oxidative, neutrophil-mediated killing. We tested whether the hydrogen peroxide, LL-37, and neutrophil hypersensitivity phenotypes in non-piliated N. gonorrhoeae could be due to elevated iron levels. Iron chelation in the growth medium rescued a nonpiliated pilE mutant from both hydrogen peroxide- and antimicrobial peptide LL-37-mediated killing, suggesting these phenotypes are related to iron availability. We used the antibiotic streptonigrin, which depends on free cytoplasmic iron and oxidation to kill bacteria, to determine whether piliation affected intracellular iron levels. Several non-piliated, loss-of-function mutants were more sensitive to streptonigrin killing than the piliated parental strain. Consistent with the idea that higher available iron levels in the under- and non-piliated strains were responsible for the higher streptonigrin sensitivity, iron limitation by desferal chelation restored resistance to streptonigrin in these strains and the addition of iron restored the sensitivity to streptonigrin killing. The antioxidants tiron and dimethylthiourea rescued the pilE mutant from streptonigrin-mediated killing, suggesting that the elevated labile iron pool in non-piliated bacteria leads to streptonigrin-dependent reactive oxygen species production. These antioxidants did not affect LL-37-mediated killing. We confirmed that the pilE mutant is not more sensitive to other antibiotics showing that the streptonigrin phenotypes are not due to general bacterial envelope disruption. The total iron content of the cell was unaltered by piliation when measured using ICP-MS suggesting that only the labile iron pool is affected by piliation. These results support the hypothesis that piliation state affects N. gonorrhoeae iron homeostasis and influences sensitivity to various host-derived antimicrobial agents.


Assuntos
Peróxido de Hidrogênio , Neisseria gonorrhoeae , Proteínas de Bactérias/genética , Fímbrias Bacterianas , Peróxido de Hidrogênio/farmacologia , Ferro , Neisseria gonorrhoeae/genética , Estreptonigrina
4.
mSphere ; 6(6): e0070921, 2021 12 22.
Artigo em Inglês | MEDLINE | ID: mdl-34817237

RESUMO

In Acinetobacter baumannii, resistance-nodulation-cell division (RND)-type efflux is a resistance mechanism of great importance since it contributes to reduced susceptibility to multiple antimicrobial compounds. Some mutations within the genes encoding the two-component regulatory system AdeRS appear to play a major role in increased expression of the RND efflux pump AdeABC and, consequently, in reduced antimicrobial susceptibility, as they are commonly observed in multidrug-resistant (MDR) A. baumannii. In the present study, the impact of frequently identified amino acid substitutions, namely, D21V and D26N in AdeR and T156M in AdeS, on adeB expression, efflux activity, and antimicrobial susceptibility was investigated. Reverse transcription-quantitative PCR (qRT-PCR) studies revealed significantly increased adeB expression caused by D26N (AdeR) and T156M (AdeS). In addition, accumulation assays have shown that these mutations induce increased efflux activity. Subsequently, antimicrobial susceptibility testing via agar dilution and broth microdilution confirmed the importance of these substitutions for the MDR phenotype, as the MICs for various antimicrobials of different classes were increased. In contrast, the amino acid substitution D21V in AdeR did not lead to increased adeB expression and did not reduce antimicrobial susceptibility. This study demonstrates the impact of the D26N (AdeR) and T156M (AdeS) amino acid substitutions, highlighting that these regulators represent promising targets for interfering with efflux activity to restore antimicrobial susceptibility. IMPORTANCE The active efflux of antimicrobials by bacteria can lead to antimicrobial resistance and persistence and can affect multiple different classes of antimicrobials. Efflux pumps are tightly regulated, and their overexpression can be mediated by changes in their regulators. Identifying these changes is one step in the direction of resistance prediction, but it also opens the possibility of targeting efflux pump regulation as a strategy to overcome antimicrobial resistance. Here, we have investigated commonly found changes in the regulators of the main efflux pumps in Acinetobacter baumannii.


Assuntos
Acinetobacter baumannii/efeitos dos fármacos , Proteínas de Bactérias/genética , Proteínas de Ligação a DNA/genética , Proteínas de Membrana Transportadoras/metabolismo , Acinetobacter baumannii/genética , Acinetobacter baumannii/metabolismo , Substituição de Aminoácidos , Antibacterianos/farmacologia , Proteínas de Bactérias/metabolismo , Proteínas de Ligação a DNA/metabolismo , Farmacorresistência Bacteriana Múltipla , Etídio/farmacocinética , Regulação Bacteriana da Expressão Gênica/efeitos dos fármacos , Proteínas de Membrana Transportadoras/genética , Testes de Sensibilidade Microbiana
5.
J Hosp Infect ; 116: 1-9, 2021 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-34298033

RESUMO

BACKGROUND: Meningitis and spinal infections with Gram-negative bacteria after local injections for treatment of chronic back pain are rare. This study investigated an outbreak of Pseudomonas aeruginosa infections following computed tomography (CT)-guided spinal injections (SI). METHODS: A case was defined as a spinal infection or meningitis with P. aeruginosa after SI between 10th January and 1st March 2019 in the same outpatient clinic. Patients without microbiological evidence of P. aeruginosa but with a favourable response to antimicrobial therapy active against P. aeruginosa were defined as probable cases. FINDINGS: Twenty-eight of 297 patients receiving CT-guided SI during the study period developed meningitis or spinal infections. Medical records were available for 19 patients. In 15 patients, there was microbiological evidence of P. aeruginosa, and four patients were defined as probable cases. Two of 19 patients developed meningitis, while the remaining 17 patients developed spinal infections. The median time from SI to hospital admission was 8 days (interquartile range 2-23 days). Patients mainly presented with back pain (N=18; 95%), and rarely developed fever (N=3; 16%). Most patients required surgery (N=16; 84%). Seven patients (37%) relapsed and one patient died. Although the source of infection was not identified microbiologically, documented failures in asepsis when performing SI probably contributed to these infections. CONCLUSIONS: SI is generally considered safe, but non-adherence to asepsis can lead to deleterious effects. Spinal infections caused by P. aeruginosa are difficult to treat and have a high relapse rate.


Assuntos
Infecções por Pseudomonas , Antibacterianos/uso terapêutico , Surtos de Doenças , Humanos , Injeções Espinhais , Infecções por Pseudomonas/tratamento farmacológico , Infecções por Pseudomonas/epidemiologia , Pseudomonas aeruginosa , Tomografia Computadorizada por Raios X
6.
J Infect ; 83(3): 314-320, 2021 09.
Artigo em Inglês | MEDLINE | ID: mdl-34146597

RESUMO

OBJECTIVES: Staphylococcus aureus is the most common cause of pyogenic vertebral osteomyelitis (VO). Studies indicate that S. aureus VO results in poor outcome. We aimed to investigate risk factors for treatment failure in patients with Staphylococcus aureus bloodstream infection (SAB) and VO. METHODS: We conducted a post hoc-analysis of data from a German bi-center prospective SAB cohort (2006-2014). Patients were followed-up for one year. Primary outcome was treatment failure defined as relapse and/or death within one year. RESULTS: A total of 1069 patients with SAB were analyzed, with 92 VO patients. In addition to antibiotic treatment, surgery was performed in 60/92 patients. Treatment failed in 44/92 patients (death, n = 42; relapse, n = 2). Multivariable analysis revealed higher age (HR 1.04 [per year], 95%CI 1.01-1.07), Charlson comorbidity index (HR 1.20, 95%CI 1.06-1.36), presence of neurologic deficits (HR 2.53, 95%CI 1.15-5.53) and local abscess formation (HR 3.35, 95%CI 1.39-8.04) as independent risk factors for treatment failure. In contrast, surgery seemed to be associated with a favourable outcome (HR 0.45 (95%CI 0.20-0.997)). CONCLUSION: SAB patients with VO exhibit a high treatment failure rate. Red flags are older age, comorbidities, neurologic deficits and local abscess formation. Whether these patients benefit from intensified treatment (e.g. radical surgery, prolongation of antibiotics) should be investigated further.


Assuntos
Bacteriemia , Osteomielite , Infecções Estafilocócicas , Idoso , Antibacterianos/uso terapêutico , Bacteriemia/tratamento farmacológico , Bacteriemia/epidemiologia , Humanos , Osteomielite/tratamento farmacológico , Osteomielite/epidemiologia , Estudos Prospectivos , Fatores de Risco , Infecções Estafilocócicas/tratamento farmacológico , Infecções Estafilocócicas/epidemiologia , Staphylococcus aureus , Falha de Tratamento
7.
mBio ; 12(3): e0072121, 2021 06 29.
Artigo em Inglês | MEDLINE | ID: mdl-34060328

RESUMO

The bacterium Neisseria gonorrhoeae (Ngo) is the main cause of the sexually transmitted infection gonorrhea. The global incidence of 87 million new Ngo infections each year, rising infection rates, and the emergence of Ngo strains that are resistant to all clinically recommended antibiotics have raised the specter of untreatable infections (M. Unemo, H. S. Seifert, E. W. Hook, III, S. Hawkes, et al., Nat Rev Dis Primers 5:79, 2019, https://doi.org/10.1038/s41572-019-0128-6). Given their abundance in symptomatic disease, neutrophils are central to both Ngo infection and consequent damage to host tissues. This article highlights present knowledge and the main open questions about Ngo-neutrophil interactions in immunity versus disease pathogenesis.


Assuntos
Neisseria gonorrhoeae/metabolismo , Neisseria gonorrhoeae/patogenicidade , Neutrófilos/metabolismo , Gonorreia/microbiologia , Humanos , Neisseria gonorrhoeae/imunologia , Neutrófilos/imunologia
8.
Antimicrob Agents Chemother ; 65(8): e0057021, 2021 07 16.
Artigo em Inglês | MEDLINE | ID: mdl-34097477

RESUMO

The Acinetobacter baumannii RND efflux pump AdeABC is regulated by the 2-component regulator AdeRS. In this study, we compared the regulation and expression of AdeABC of the reference strains ATCC 17978 and ATCC 19606. A clearly stronger efflux activity was demonstrated for ATCC 19606. An amino acid substitution at residue 172 of adeS was identified as a potential cause for differential expression of the pump. Therefore, we recommend caution with exclusively using single reference strains for research.


Assuntos
Acinetobacter baumannii , Acinetobacter baumannii/genética , Acinetobacter baumannii/metabolismo , Antibacterianos/farmacologia , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Farmacorresistência Bacteriana/genética , Farmacorresistência Bacteriana Múltipla/genética , Proteínas de Membrana Transportadoras/genética , Testes de Sensibilidade Microbiana
9.
J Hosp Infect ; 108: 158-167, 2021 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-33290816

RESUMO

BACKGROUND: Carbapenem resistance in Gram-negative bacteria is associated with severe infections in the hospital setting. No uniform screening policy or agreed set of criteria exists within the EU to inform treatment decisions for infections caused by carbapenem-resistant Gram-negative bacteria. AIM: To develop a range of consensus statements to survey experts in carbapenem resistance, to identify potential similarities and differences across the EU and across specialties. METHODS: The survey contained 43 statements, covering six key topics relating to carbapenem-resistant organisms: microbiological screening; diagnosis; infection control implementation; antibiotic stewardship; use of resources; and influencing policy. FINDINGS: In total, 136 survey responses were received (66% infectious disease specialists, 18% microbiologists, 11% intensive care specialists, 4% other/unknown) from France, Germany, Greece, Italy, Spain, and the UK. High, or very high, levels of agreement were seen for all 43 consensus statements, indicating good alignment concerning early identification and optimal management of infection due to carbapenem-resistant organisms. CONCLUSION: We offer the following recommendations: (1) screening is required when a patient may have been exposed to the healthcare system in countries/hospitals where carbapenem-resistant organisms are endemic; (2) rapid diagnostic tools should be available in every institution; (3) all institutions should have a specific policy for the control of carbapenem-resistant organisms, which is routinely audited; (4) clear strategies are required to define both appropriate and inappropriate use of carbapenems; (5) priority funding should be allocated to the management of infections due to carbapenem-resistant organisms; and (6) international co-operation is required to reduce country-to-country transmission of carbapenem-resistant organisms.


Assuntos
Antibacterianos/farmacologia , Carbapenêmicos/farmacologia , Farmacorresistência Bacteriana , Infecções por Bactérias Gram-Negativas , Gestão de Antimicrobianos , Consenso , França , Alemanha , Bactérias Gram-Negativas , Infecções por Bactérias Gram-Negativas/tratamento farmacológico , Grécia , Humanos , Controle de Infecções , Itália , Espanha , Reino Unido
10.
mBio ; 11(5)2020 10 27.
Artigo em Inglês | MEDLINE | ID: mdl-33109763

RESUMO

Neisseria gonorrhoeae relies on type IV pili (T4p) to promote colonization of their human host and to cause the sexually transmitted infection gonorrhea. This organelle cycles through a process of extension and retraction back into the bacterial cell. Through a genetic screen, we identified the NGO0783 locus of N. gonorrhoeae strain FA1090 as containing a gene encoding a protein required to stabilize the type IV pilus in its extended, nonretracted conformation. We have named the gene tfpC and the protein TfpC. Deletion of tfpC produces a nonpiliated colony morphology, and immuno-transmission electron microscopy confirms that the pili are lost in the ΔtfpC mutant, although there is some pilin detected near the bacterial cell surface. A copy of the tfpC gene expressed from a lac promoter restores pilus expression and related phenotypes. A ΔtfpC mutant shows reduced levels of pilin protein, but complementation with a tfpC gene restored pilin to normal levels. Bioinformatic searches show that there are orthologues in numerous bacterial species, but not all type IV pilin-expressing bacteria contain orthologous genes. Coevolution and nuclear magnetic resonance (NMR) analysis indicates that TfpC contains an N-terminal transmembrane helix, a substantial extended/unstructured region, and a highly charged C-terminal coiled-coil domain.IMPORTANCE Most bacterial species express one or more extracellular organelles called pili/fimbriae that are required for many properties of each bacterial cell. The Neisseria gonorrhoeae type IV pilus is a major virulence and colonization factor for the sexually transmitted infection gonorrhea. We have discovered a new protein of Neisseria gonorrhoeae called TfpC that is required to maintain type IV pili on the bacterial cell surface. There are similar proteins found in other members of the Neisseria genus and many other bacterial species important for human health.


Assuntos
Proteínas de Bactérias/genética , Fímbrias Bacterianas/fisiologia , Neisseria gonorrhoeae/genética , Sequência de Aminoácidos , Proteínas de Bactérias/metabolismo , DNA Bacteriano/genética , Fímbrias Bacterianas/classificação , Regulação Bacteriana da Expressão Gênica , Neisseria gonorrhoeae/metabolismo , Fenótipo , Domínios Proteicos , Virulência
11.
Biochemistry ; 59(10): 1104-1112, 2020 03 17.
Artigo em Inglês | MEDLINE | ID: mdl-32078293

RESUMO

Neisseria gonorrhoeae possesses a programmed recombination system that allows the bacteria to alter the major subunit of the type IV pilus, pilin or PilE. An alternate DNA structure known as a guanine quadruplex (G4) is required for pilin antigenic variation (pilin Av). The G-C base pairs within the G4 motif are required for pilin Av, but simple mutation of the loop bases does not affect pilin Av. We show that more substantial changes to the loops, in both size and nucleotide composition, with the core guanines unchanged, decrease or abrogate pilin Av. We investigated why these loop changes might influence the efficiency of pilin Av. RecA is a recombinase required for pilin Av that can bind the pilE G4 in vitro. RecA binds different G4 structures with altered loops with varied affinities. However, changes in RecA binding affinities to the loop mutants do not absolutely correlate with the pilin Av phenotypes. Interestingly, the yeast RecA ortholog, Rad51, also binds the pilE G4 structure with a higher affinity than it binds single-stranded DNA, suggesting that RecA G4 binding is conserved in eukaryotic orthologs. The thermal stability the pilE G4 structure and its loop mutants showed that the parental G4 structure had the highest melting temperature, and the melting temperature of the loop mutants correlated with pilin Av phenotype. These results suggest that the folding kinetics and stability of G4 structures are important for the efficiency of pilin Av.


Assuntos
Proteínas de Fímbrias/metabolismo , Neisseria gonorrhoeae/genética , Variação Antigênica/genética , Pareamento de Bases/genética , Proteínas de Fímbrias/química , Proteínas de Fímbrias/genética , Fímbrias Bacterianas/genética , Fímbrias Bacterianas/metabolismo , Quadruplex G , Guanina/metabolismo , Mutação/genética , Neisseria gonorrhoeae/imunologia , Ligação Proteica/genética , Recombinação Genética/genética
12.
Nat Rev Dis Primers ; 5(1): 79, 2019 11 21.
Artigo em Inglês | MEDLINE | ID: mdl-31754194

RESUMO

The bacterium Neisseria gonorrhoeae causes the sexually transmitted infection (STI) gonorrhoea, which has an estimated global annual incidence of 86.9 million adults. Gonorrhoea can present as urethritis in men, cervicitis or urethritis in women, and in extragenital sites (pharynx, rectum, conjunctiva and, rarely, systemically) in both sexes. Confirmation of diagnosis requires microscopy of Gram-stained samples, bacterial culture or nucleic acid amplification tests. As no gonococcal vaccine is available, prevention relies on promoting safe sexual behaviours and reducing STI-associated stigma, which hinders timely diagnosis and treatment thereby increasing transmission. Single-dose systemic therapy (usually injectable ceftriaxone plus oral azithromycin) is the recommended first-line treatment. However, a major public health concern globally is that N. gonorrhoeae is evolving high levels of antimicrobial resistance (AMR), which threatens the effectiveness of the available gonorrhoea treatments. Improved global surveillance of the emergence, evolution, fitness, and geographical and temporal spread of AMR in N. gonorrhoeae, and improved understanding of the pharmacokinetics and pharmacodynamics for current and future antimicrobials in the treatment of urogenital and extragenital gonorrhoea, are essential to inform treatment guidelines. Key priorities for gonorrhoea control include strengthening prevention, early diagnosis, and treatment of patients and their partners; decreasing stigma; expanding surveillance of AMR and treatment failures; and promoting responsible antimicrobial use and stewardship. To achieve these goals, the development of rapid and affordable point-of-care diagnostic tests that can simultaneously detect AMR, novel therapeutic antimicrobials and gonococcal vaccine(s) in particular is crucial.


Assuntos
Gonorreia/complicações , Gonorreia/fisiopatologia , Adolescente , Adulto , Antibacterianos/uso terapêutico , Azitromicina/uso terapêutico , Ceftriaxona/uso terapêutico , Etnicidade/estatística & dados numéricos , Feminino , Gonorreia/epidemiologia , Humanos , Masculino , Neisseria gonorrhoeae/efeitos dos fármacos , Neisseria gonorrhoeae/patogenicidade , Fatores Sexuais , Classe Social
13.
mSphere ; 4(5)2019 10 02.
Artigo em Inglês | MEDLINE | ID: mdl-31578246

RESUMO

Gene diversification is a common mechanism pathogens use to alter surface structures to aid in immune avoidance. Neisseria gonorrhoeae uses a gene conversion-based diversification system to alter the primary sequence of the gene encoding the major subunit of the pilus, pilE Antigenic variation occurs when one of the nonexpressed 19 silent copies donates part of its DNA sequence to pilE We have developed a method using Pacific Biosciences (PacBio) amplicon sequencing and custom software to determine pilin antigenic variation frequencies. The program analyzes 37 variable regions across the strain FA1090 1-81-S2 pilE gene and can be modified to determine sequence variation from other starting pilE sequences or other diversity generation systems. Using this method, we measured pilin antigenic variation frequencies for various derivatives of strain FA1090 and showed we can also analyze pilin antigenic variation frequencies during macrophage infection.IMPORTANCE Diversity generation systems are used by many unicellular organism to provide subpopulations of cell with different properties that are available when needed. We have developed a method using the PacBio DNA sequencing technology and a custom computer program to analyze the pilin antigenic variation system of the organism that is the sole cause of the sexually transmitted infection, gonorrhea.


Assuntos
Variação Antigênica , Proteínas de Fímbrias/genética , Neisseria gonorrhoeae/genética , Análise de Sequência de DNA/métodos , Proteínas de Fímbrias/imunologia , Gonorreia/microbiologia , Humanos , Software , Células U937
15.
J Prev Alzheimers Dis ; 6(3): 164-168, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31062826

RESUMO

Combination therapy is expected to play an important role for the treatment of Alzheimer's disease (AD). In October 2018, the European Union-North American Clinical Trials in Alzheimer's Disease Task Force (EU/US CTAD Task Force) met to discuss scientific, regulatory, and logistical challenges to the development of combination therapy for AD and current efforts to address these challenges. Task Force members unanimously agreed that successful treatment of AD will likely require combination therapy approaches that target multiple mechanisms and pathways. They further agreed on the need for global collaboration and sharing of data and resources to accelerate development of such approaches.


Assuntos
Doença de Alzheimer/tratamento farmacológico , Desenvolvimento de Medicamentos , Comitês Consultivos , Animais , Ensaios Clínicos como Assunto , Quimioterapia Combinada , Humanos , Resultado do Tratamento
16.
J Mol Biol ; 431(16): 3010-3014, 2019 07 26.
Artigo em Inglês | MEDLINE | ID: mdl-30986425

RESUMO

The 10 human-restricted Neisseria species all colonize mucosal surfaces, but show a spectrum of pathogenicity. The commensal Neisseria do not normally cause pathology, while the two pathogenic species, Neisseria meningitidis and Neisseria gonorrhoeae, straddle the border between commensalism and pathogenicity. Why the pathogenic Neisseria continue to mediate host damage after thousands of years of co-evolution with their human host, and why the commensal species have not acquired the ability to damage the host, if this capability provides a selective advantage, is not understood. One way the pathogenic species are different from the commensal species is by their ability to induce PMN inflammation, which is dependent on the site of colonization. I discuss how the site of colonization dictates whether copious inflammation occurs with both pathogenic species. I put forth a model that posits that an ancestor of both pathogenic species changed colonization site from the oral cavity to the genital tract of a human or humanoid and had to evolve multiple, new traits - to induce PMN inflammation and avoid adaptive immunity - to allow efficient sexual transmission. This model predicts that PMN inflammation produces the serious sequelae of gonorrhea and increases the probability that N. meningitidis might exit the oral cavity to produce systemic disease. In both cases, the pathology produced by these host-adapted species is an unintended by product of the inflammation but host damage does not provide any selective advantage for these organisms.


Assuntos
Neisseria/imunologia , Neisseria/patogenicidade , Neutrófilos/metabolismo , Especificidade de Hospedeiro , Interações Hospedeiro-Patógeno , Humanos , Neisseria/classificação , Neisseria/fisiologia , Neisseria gonorrhoeae/imunologia , Neisseria gonorrhoeae/patogenicidade , Neisseria meningitidis/imunologia , Neisseria meningitidis/patogenicidade , Simbiose
17.
J Bacteriol ; 201(13)2019 07 01.
Artigo em Inglês | MEDLINE | ID: mdl-30988037

RESUMO

The major subunit of the type IV pilus (T4p) of Neisseria gonorrhoeae undergoes antigenic variation (AV) dependent on a guanine quadruplex (G4) DNA structure located upstream of the pilin gene. Since the presence of G4 DNA induces genome instability in both eukaryotic and prokaryotic chromosomes, we tested whether a double-strand break (DSB) at the site of the pilE G4 sequence could substitute for G4-directed pilin AV. The G4 motif was replaced by an I-SceI cut site, and the cut site was also introduced to locations near the origin of replication and the terminus. Expression of the I-SceI endonuclease from an irrelevant chromosomal site confirmed that the endonuclease functions to induce double-strand breaks at all three locations. No antigenic variants were detected when the G4 was replaced with the I-SceI cut site, but there was a growth defect from having a DSB in the chromosome, and suppressor mutations that were mainly deletions of the cut site and/or the entire pilE gene accumulated. Thus, the pilE G4 does not act to promote pilin AV by generating a DSB but requires either a different type of break, a nick, or more complex interactions with other factors to stimulate this programmed recombination system.IMPORTANCENeisseria gonorrhoeae, the causative agent of gonorrhea, possesses a DNA recombination system to change one of its surface-exposed antigens. This recombination system, known as antigenic variation, uses an alternate DNA structure to initiate variation. The guanine quadruplex DNA structure is known to cause nicks or breaks in DNA; however, much remains unknown about how this structure functions in cells. We show that inducing a break by different means does not allow antigenic variation, indicating that the DNA structure may have a more complicated role.


Assuntos
Variação Antigênica , Quebras de DNA de Cadeia Dupla , Proteínas de Fímbrias/imunologia , Neisseria gonorrhoeae/genética , Antígenos de Bactérias/genética , Antígenos de Bactérias/imunologia , DNA Bacteriano/genética , Proteínas de Fímbrias/genética , Fímbrias Bacterianas/imunologia , Quadruplex G , Recombinação Genética
18.
Clin Microbiol Infect ; 25(11): 1399-1407, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-30980927

RESUMO

OBJECTIVES: High-quality diagnosis of bloodstream infections (BSI) is important for successful patient management. As knowledge on current practices of microbiological BSI diagnostics is limited, this project aimed to assess its current state in European microbiological laboratories. METHODS: We performed an online questionnaire-based cross-sectional survey comprising 34 questions on practices of microbiological BSI diagnostics. The ESCMID Study Group for Bloodstream Infections, Endocarditis and Sepsis (ESGBIES) was the primary platform to engage national coordinators who recruited laboratories within their countries. RESULTS: Responses were received from 209 laboratories in 25 European countries. Although 32.5% (68/209) of laboratories only used the classical processing of positive blood cultures (BC), two-thirds applied rapid technologies. Of laboratories that provided data, 42.2% (78/185) were able to start incubating BC in automated BC incubators around-the-clock, and only 13% (25/192) had established a 24-h service to start immediate processing of positive BC. Only 4.7% (9/190) of laboratories validated and transmitted the results of identification and antimicrobial susceptibility testing (AST) of BC pathogens to clinicians 24 h/day. Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry from briefly incubated sub-cultures on solid media was the most commonly used approach to rapid pathogen identification from positive BC, and direct disc diffusion was the most common rapid AST method from positive BC. CONCLUSIONS: Laboratories have started to implement novel technologies for rapid identification and AST for positive BC. However, progress is severely compromised by limited operating hours such that current practice of BC diagnostics in Europe complies only partly with the requirements for optimal BSI management.


Assuntos
Testes Diagnósticos de Rotina/métodos , Técnicas Microbiológicas/métodos , Técnicas de Diagnóstico Molecular/métodos , Sepse/diagnóstico , Estudos Transversais , Europa (Continente) , Humanos
19.
PLoS One ; 14(2): e0212444, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30779810

RESUMO

BACKGROUND: Effective interdisciplinary communication of imaging findings is vital for patient care, as referring physicians depend on the contained information for the decision-making and subsequent treatment. Traditional radiology reports contain non-structured free text and potentially tangled information in narrative language, which can hamper the information transfer and diminish the clarity of the report. Therefore, this study investigates whether newly developed structured reports (SRs) of prostate magnetic resonance imaging (MRI) can improve interdisciplinary communication, as compared to non-structured reports (NSRs). METHODS: 50 NSRs and 50 SRs describing a single prostatic lesion were presented to four urologists with expert level experience in prostate cancer surgery or targeted MRI TRUS fusion biopsy. They were subsequently asked to plot the tumor location in a 2-dimensional prostate diagram and to answer a questionnaire focusing on information on clinically relevant key features as well as the perceived structure of the report. A validated scoring system that distinguishes between "major" and "minor" mistakes was used to evaluate the accuracy of the plotting of the tumor position in the prostate diagram. RESULTS: The mean total score for accuracy for SRs was significantly higher than for NSRs (28.46 [range 13.33-30.0] vs. 21.75 [range 0.0-30.0], p < 0.01). The overall rates of major mistakes (54% vs. 10%) and minor mistakes (74% vs. 22%) were significantly higher (p < 0.01) for NSRs than for SRs. The rate of radiologist re-consultations was significantly lower (p < 0.01) for SRs than for NSRs (19% vs. 85%). Furthermore, SRs were rated as significantly superior to NSRs in regard to determining the clinical tumor stage (p < 0.01), the quality of the summary (4.4 vs. 2.5; p < 0.01), and overall satisfaction with the report (4.5 vs. 2.3; p < 0.01), and as more valuable for further clinical decision-making and surgical planning (p < 0.01). CONCLUSIONS: Structured reporting of prostate MRI has the potential to improve interdisciplinary communication. Through SRs, expert urologists were able to more accurately assess the exact location of single prostate cancer lesions, which can facilitate surgical planning. Furthermore, structured reporting of prostate MRI leads to a higher satisfaction level of the referring physician.


Assuntos
Controle de Formulários e Registros/métodos , Comunicação Interdisciplinar , Próstata/diagnóstico por imagem , Projetos de Pesquisa/tendências , Confiabilidade dos Dados , Tomada de Decisões , Erros de Diagnóstico , Humanos , Biópsia Guiada por Imagem , Imageamento por Ressonância Magnética/métodos , Masculino , Neoplasias da Próstata/patologia , Radiologistas , Encaminhamento e Consulta , Relatório de Pesquisa , Inquéritos e Questionários , Urologistas
20.
Clin Microbiol Infect ; 25(8): 1013-1020, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-30641228

RESUMO

OBJECTIVES: Colonization and infection with third-generation cephalosporin-resistant Escherichia coli (3GCR-EC) are frequent in haematological and oncological patients. In this high-risk setting, German guidelines recommend single-room contact precautions (SCP) for patients with 3GCR-EC that are non-susceptible to fluoroquinolones (F3GCR-EC). However, this recommendation is controversial, as evidence is limited. METHODS: We performed a prospective, multicentre cohort study at four haematology and oncology departments assessing the impact of SCP on hospital-acquired colonization or bloodstream infection (BSI) with F3GCR-EC. Two sites performed SCP for F3GCR-EC patients including single rooms, gloves and gowns (SCP sites), and two did not (NCP sites). Active screening for 3GCR-EC was performed and isolates were characterized with molecular typing methods including whole genome sequencing and core genome multiple locus sequence typing to assess patient-to-patient transmission. Potential confounders were assessed by competing-risk regression analysis. RESULTS: Within 12 months, 1386 patients at NCP sites and 1582 patients at SCP sites were included. Hospital-acquisition of F3GCR-EC was observed in 22/1386 (1.59%) and 16/1582 (1.01%) patients, respectively (p 0.191). There were 3/1386 (0.22%) patients with BSI caused by F3GCR-EC at NCP sites and 4/1582 (0.25%) at SCP sites (p 1.000). Patient-to-patient transmission occurred in three cases at NCP and SCP sites each (p 1.000). The number of patients needed to screen in order to prevent one patient-to-patient transmission of F3GCR-EC was determined to be 3729. CONCLUSIONS: Use of SCP had no significant impact on hospital-acquisition or patient-to-patient transmission of F3GCR-EC in this high-risk setting.


Assuntos
Infecção Hospitalar/prevenção & controle , Infecções por Escherichia coli/prevenção & controle , Controle de Infecções/métodos , Precauções Universais , Adulto , Idoso , Bacteriemia/prevenção & controle , Bacteriemia/transmissão , Infecção Hospitalar/microbiologia , Farmacorresistência Bacteriana Múltipla , Escherichia coli/isolamento & purificação , Feminino , Luvas Protetoras , Hematologia , Unidades Hospitalares/estatística & dados numéricos , Humanos , Masculino , Pessoa de Meia-Idade , Serviço Hospitalar de Oncologia , Estudos Prospectivos
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