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BACKGROUND: Aspergillus fumigatus is the most common filamentous fungus isolated from the airways of people with cystic fibrosis (CF). The aim of this study was to investigate how chronic A. fumigatus colonization affects lung function in people with CF, to identify risk factors for colonization, and to evaluate antifungal treatment of asymptomatic Aspergillus colonization. METHODS: Data from 2014-2018 was collected from the Swedish CF registry and medical records. Baseline data before the start of A. fumigatus colonization was compared with the two succeeding years to evaluate how colonization and treatment affected lung function and other clinical aspects. RESULTS: A total of 437 patients were included, of which 64 (14.6%) became colonized with A. fumigatus during the study period. Inhaled antibiotics was associated with A. fumigatus colonization (adjusted OR 3.1, 95% CI 1.6-5.9, p < 0.05). Fungal colonization was not associated with a more rapid lung function decline or increased use of IV-antibiotics compared to the non-colonized group, but patients with A. fumigatus had more hospital days, a higher increase of total IgE, and higher eosinophil counts. In the Aspergillus group, 42 patients were considered to be asymptomatic. Of these, 19 patients received antifungal treatment. Over the follow up period, the treated group had a more pronounced decrease in percent predicted Forced Expiratory Volume in one second (ppFEV1) compared to untreated patients (- 8.7 vs - 1.4 percentage points, p < 0.05). CONCLUSION: Inhaled antibiotics was associated with A. fumigatus colonization, but no association was found between persistent A. fumigatus and subsequent lung function decline. No obvious benefits of treating asymptomatic A. fumigatus colonization were demonstrated.
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Aspergillus fumigatus , Fibrosis Quística , Antibacterianos/uso terapéutico , Antifúngicos/uso terapéutico , Infecciones Asintomáticas , Estudios de Casos y Controles , Fibrosis Quística/complicaciones , Fibrosis Quística/tratamiento farmacológico , Fibrosis Quística/microbiología , Humanos , Pulmón , Infección Persistente , Sistema de RegistrosRESUMEN
BACKGROUND: Lung transplant (LTx) recipients are at increased risk for airway infections, but the cause of infection is often difficult to establish with traditional culture-based techniques. The objectives of the study was to compare the airway microbiome in LTx patients with and without ongoing airway infection and identify differences in their microbiome composition. METHODS: LTx recipients were prospectively followed with bronchoalveolar lavage (BAL) during the first year after transplantation. The likelihood of airway infection at the time of sampling was graded based on clinical criteria and BAL cultures, and BAL fluid levels of the inflammatory markers heparin-binding protein (HBP), IL-1ß and IL-8 were determined with ELISA. The bacterial microbiome of the samples were analysed with 16S rDNA sequencing and characterized based on richness and evenness. The distance in microbiome composition between samples were determined using Bray-Curtis and weighted and unweighted UniFrac. RESULTS: A total of 46 samples from 22 patients were included in the study. Samples collected during infection and samples with high levels of inflammation were characterized by loss of bacterial diversity and a significantly different species composition. Burkholderia, Corynebacterium and Staphylococcus were enriched during infection and inflammation, whereas anaerobes and normal oropharyngeal flora were less abundant. The most common findings in BAL cultures, including Pseudomonas aeruginosa, were not enriched during infection. CONCLUSION: This study gives important insights into the dynamics of the airway microbiome of LTx recipients, and suggests that lung infections are associated with a disruption in the homeostasis of the microbiome.
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Bacterias/crecimiento & desarrollo , Trasplante de Pulmón , Pulmón/microbiología , Microbiota , Infecciones del Sistema Respiratorio/microbiología , Adulto , Anciano , Bacterias/aislamiento & purificación , Líquido del Lavado Bronquioalveolar/microbiología , Disbiosis , Femenino , Humanos , Interleucina-1beta/metabolismo , Interleucina-8/metabolismo , Pulmón/metabolismo , Pulmón/cirugía , Trasplante de Pulmón/efectos adversos , Masculino , Persona de Mediana Edad , Estudios Prospectivos , Infecciones del Sistema Respiratorio/diagnóstico , Infecciones del Sistema Respiratorio/metabolismo , Factores de Tiempo , Resultado del Tratamiento , Adulto JovenRESUMEN
We present characteristics of infective endocarditis (IE) caused by Staphylococcus lugdunensis and compare with IE caused by Staphylococcus aureus and other CoNS, in the National Swedish Registry of IE (2008-2018). Thirty episodes of S. lugdunensis IE were registered, of which 21 cases affected native valves, and 7 patients were subjected to surgery. The mortality rate at 30 days was significantly higher for S. lugdunensis IE (20%, n = 6), than for IE caused by other CoNS (7%) or S. aureus (9%) p = 0.016. Septic embolisation was only reported in two cases (7%). The most common treatment was isoxazolyl penicillin (n = 18).
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Endocarditis Bacteriana/microbiología , Infecciones Estafilocócicas/microbiología , Staphylococcus lugdunensis , Anciano , Endocarditis Bacteriana/epidemiología , Femenino , Humanos , Masculino , Persona de Mediana Edad , Sistema de Registros , Estudios Retrospectivos , Infecciones Estafilocócicas/epidemiología , Infecciones Estafilocócicas/mortalidad , Staphylococcus aureus , Suecia/epidemiologíaRESUMEN
BACKGROUND: Staphylococcus lugdunensis belongs to the CoNS group, but is regarded to be more virulent than most other CoNS. It is also remarkably susceptible to antibiotics, including penicillin G. OBJECTIVES: To evaluate different methods for penicillin susceptibility testing, to assess penicillin susceptibility rates among S. lugdunensis and to describe the clinical presentation including antibiotic treatment. METHODS: Clinical isolates of S. lugdunensis were tested for penicillin susceptibility using disc diffusion according to CLSI (10 U disc) and EUCAST (1 U disc), assessment of zone-edge appearance, nitrocefin test and Etest for MIC determination. PCR of the blaZ gene was used as a reference method. RESULTS: Of the 112 isolates included in the study, 67% were susceptible to penicillin G according to blaZ PCR. The EUCAST disc diffusion test had 100% sensitivity, whereas the CLSI method had one very major error with a false-susceptible isolate. When zone-edge appearance was included in the assessment, the false-susceptible isolate was correctly classified as resistant. Foreign-body infection was the most common focus of infection, affecting 49% of the participants. Only 4% of the patients were treated with penicillin G. CONCLUSIONS: Penicillin susceptibility is common in S. lugdunensis and the disc diffusion method according to EUCAST had a higher sensitivity than that of CLSI. Assessment of zone-edge appearance could increase the sensitivity of the disc diffusion test. Penicillin susceptibility testing and treatment should be considered in S. lugdunensis infections.
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Staphylococcus lugdunensis , Antibacterianos/farmacología , Pruebas Antimicrobianas de Difusión por Disco , Humanos , Pruebas de Sensibilidad Microbiana , Penicilina G/farmacología , Penicilinas/farmacologíaRESUMEN
BACKGROUND: Group A streptococci (GAS) are known to cause serious invasive infections, but little is known about outcomes when patients with these infections are admitted to intensive care. We wanted to describe critically ill patients with severe sepsis or septic shock due to invasive GAS (iGAS) and compare them with other patients with severe sepsis or septic shock. METHODS: Adult patients admitted to a general intensive care unit (ICU) in Sweden (2007-2019) were screened for severe sepsis or septic shock according to Sepsis 2 definition. Individuals with iGAS infection were identified. The outcome variables were mortality, days alive and free of vasopressors and invasive mechanical ventilation, maximum acute kidney injury score for creatinine, use of continuous renal replacement therapy and maximum Sequential Organ Failure Assessment score during the ICU stay. Age, Simplified Acute Physiology Score (SAPS 3) and iGAS were used as independent, explanatory variables in regression analysis. Cox regression was used for survival analyses. RESULTS: iGAS was identified in 53 of 1021 (5.2%) patients. Patients with iGAS presented a lower median SAPS 3 score (62 [56-72]) vs 71 [61-81]), p < 0.001), had a higher frequency of cardiovascular cause of admission to the ICU (38 [72%] vs 145 [15%], p < 0.001) and had a higher median creatinine score (173 [100-311] vs 133 [86-208] µmol/L, p < 0.019). Of the GAS isolates, 50% were serotyped emm1/T1 and this group showed signs of more pronounced circulatory and renal failure than patients with non-emm1/T1 (p = 0.036 and p = 0.007, respectively). After correction for severity of illness (SAPS 3) and age, iGAS infection was associated with lower mortality risk (95% confidence interval (CI) of hazard ratio (HR) 0.204-0.746, p < 0.001). Morbidity analyses demonstrated that iGAS patients were more likely to develop renal failure. CONCLUSION: Critically ill patients with iGAS infection had a lower mortality risk but a higher degree of renal failure compared to similarly ill sepsis patients. emm1/T1 was found to be the most dominant serotype, and patients with emm1/T1 demonstrated more circulatory and renal failure than patients with other serotypes of iGAS.
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Enfermedad Crítica/mortalidad , Morbilidad/tendencias , Infecciones Estreptocócicas/mortalidad , Anciano , Enfermedad Crítica/epidemiología , Femenino , Humanos , Unidades de Cuidados Intensivos/organización & administración , Unidades de Cuidados Intensivos/estadística & datos numéricos , Masculino , Persona de Mediana Edad , Sistema de Registros/estadística & datos numéricos , Estudios Retrospectivos , Puntuación Fisiológica Simplificada Aguda , Estadísticas no Paramétricas , Infecciones Estreptocócicas/epidemiología , Suecia/epidemiologíaRESUMEN
BACKGROUND: The Gram-negative bacterium Escherichia coli, commonly involved in severe sepsis and septic shock, shed endotoxin that upon detection by the host triggers an inflammatory cascade. Efficiency of albumin solutions to restore hypovolemia during sepsis has been debated. To aid identification of subgroups of sepsis patients that may respond positively or negatively to treatment with albumin we investigated if preparations of albumin for medical use could affect endotoxin-induced inflammatory response. METHODS: Isolated human omental arteries obtained during surgery were incubated with endotoxin in the presence or absence of albumin solution. Isolated human monocytes were incubated with endotoxin in the presence or absence of five different commercially available albumin solutions. Vascular contractile response to noradrenaline and release of interleukin (IL)-1ß, IL-6, IL-8, IL-10, and tumor necrosis factor (TNF)-α were measured. RESULTS: Incubation with albumin together with endotoxin decreased median maximum contraction and increased release of IL-6 and IL-8 from the arteries compared to incubation with endotoxin alone. All albumin solutions except one significantly increased endotoxin-induced TNF-α release from monocytes. IL-6 and IL-10 were also increased and no concentration dependency of TNF-α release was observed above 2 mg mL-1 . Incubation with albumin alone did not affect contraction or release of cytokines while no potentially endotoxin-enhancing contaminant could be identified. CONCLUSION: We have shown that albumin solution in combination with endotoxin cause vasoplegia in human omental arteries, paralleled by an inflammatory response. This finding could explain the variable efficiency of albumin solutions for sepsis treatment.
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Albúminas/farmacología , Endotoxinas/efectos adversos , Inflamación/etiología , Inflamación/metabolismo , Vasoplejía/etiología , Vasoplejía/metabolismo , Femenino , Humanos , Técnicas In Vitro , Interleucina-10/metabolismo , Interleucina-1beta/metabolismo , Interleucina-6/metabolismo , Interleucina-8/metabolismo , Masculino , Factor de Necrosis Tumoral alfa/metabolismoRESUMEN
Pulmonary infection is a common complication after lung transplantation, and early detection is crucial for outcome. However, the condition can be clinically difficult to diagnose and to distinguish from rejection. The aim of this prospective study was to evaluate heparin-binding protein (HBP), lysozyme, and the cytokines interleukin (IL)-1ß, IL-6, IL-8, IL-10 and tumor necrosis factor (TNF) in bronchoalveolar lavage fluid (BALF) as potential biomarkers for pulmonary infection in lung-transplanted patients. One hundred thirteen BALF samples from 29 lung transplant recipients were collected at routine scheduled bronchoscopies at 3 and 6 months, or on clinical indication. Samples were classified into no, possible, probable, or definite infection at the time of sampling. Rejection was defined by biopsy results. HBP, lysozyme, and cytokines were analyzed in BALF and correlated to likelihood of infection and rejection. All biomarkers were significantly increased in BALF during infection, whereas patients with rejection presented low levels that were comparable to noninfection samples. HBP, IL-1ß, and IL-8 were the best diagnostic markers of infection with area under the receiver-operating characteristic curve values of 0.88, 0.91, and 0.90, respectively. In conclusion, HBP, IL-1ß, and IL-8 could be useful diagnostic markers of pulmonary infection in lung-transplanted patients.
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Péptidos Catiónicos Antimicrobianos/metabolismo , Proteínas Sanguíneas/metabolismo , Líquido del Lavado Bronquioalveolar/química , Proteínas Portadoras/metabolismo , Citocinas/metabolismo , Mediadores de Inflamación/metabolismo , Trasplante de Pulmón/efectos adversos , Muramidasa/metabolismo , Infecciones del Sistema Respiratorio/diagnóstico , Adulto , Anciano , Femenino , Estudios de Seguimiento , Humanos , Masculino , Persona de Mediana Edad , Pronóstico , Estudios Prospectivos , Infecciones del Sistema Respiratorio/etiología , Infecciones del Sistema Respiratorio/metabolismo , Adulto JovenRESUMEN
BACKGROUND: Lung transplant patients experience a high risk of airway infections and microbial colonization of the lung due to constant exposure to the environment through inhaled microorganisms, denervation, reduced ciliary transport, and decreased cough. METHODS: In this nationwide prospective study on Swedish lung transplant patients, we evaluated the microbiological panorama of bacteria, fungi, and virus found in bronchoalveolar lavage fluid (BALF) obtained the first year after lung transplantation (LTx). Differences in microbiological findings depending of concomitant signs of infection and background factors were assessed. RESULTS: A total of 470 bronchoscopies from 126 patients were evaluated. Sixty-two percent (n = 293) of BALF samples had positive microbiological finding(s). Forty-six percent (n = 217) had bacterial growth, 29% (n = 137) fungal growth, and 9% (n = 43) were positive in viral PCR. In 38% of BALF samples (n = 181), a single microbe was found, whereas a combination of bacteria, fungi or virus was found in 24% (n = 112) of bronchoscopies. The most common microbiological findings were Candida albicans, Pseudomonas aeruginosa and coagulase negative Staphylococcus (in 42 (33%), 36 (29%), and 25 (20%) patients, respectively). Microbiological findings were similar in BALF from patients with and without signs of lung infection and the frequency of multidrug resistant (MDR) bacteria was low. No significant association was found between background factors and time to first lung infection. CONCLUSION: This study gives important epidemiologic insights and reinforces that microbiological findings have to be evaluated in the light of clinical symptoms and endobronchial appearance in the assessment of lung infections in lung transplant patients.
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Líquido del Lavado Bronquioalveolar/microbiología , Trasplante de Pulmón/efectos adversos , Neumonía/microbiología , Adulto , Anciano , Broncoscopía , Candida albicans/aislamiento & purificación , Candida albicans/fisiología , Farmacorresistencia Bacteriana Múltiple , Femenino , Humanos , Masculino , Persona de Mediana Edad , Neumonía/diagnóstico , Neumonía/epidemiología , Estudios Prospectivos , Pseudomonas aeruginosa/aislamiento & purificación , Pseudomonas aeruginosa/fisiología , Staphylococcus/aislamiento & purificación , Staphylococcus/fisiología , Suecia/epidemiología , Adulto JovenRESUMEN
BACKGROUND: Cystic fibrosis (CF) is associated with bacterial pulmonary infections and neutrophil-dominated inflammation in the airways. The aim of this study was to evaluate the neutrophil-derived protein Heparin-binding protein (HBP) as a potential sputum marker of airway inflammation and bacterial load. METHODS: Nineteen CF patients, aged 6-18 years, were prospectively followed for 6 months with sputum sampling at every visit to the CF clinic. A total of 41 sputum samples were collected. Sputum-HBP was analysed with ELISA, neutrophil elastase activity with a chromogenic assay, and total bacterial load with RT-PCR of the 16 s rDNA gene. Data were compared to lung function parameters and airway symptoms. RESULTS: HBP and elastase correlated to a decrease in FEV1%predicted compared to the patients´ individual baseline pulmonary function (∆FEV1), but not to bacterial load. Area under the receiver operating characteristic curve values for the detection of > 10% decrease in ∆FEV1 were 0.80 for HBP, 0.78 for elastase, and 0.54 for bacterial load. CONCLUSIONS: Sputum HBP is a promising marker of airway inflammation and pulmonary function in children with CF.
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Péptidos Catiónicos Antimicrobianos/análisis , Carga Bacteriana , Proteínas Sanguíneas/análisis , Proteínas Portadoras/análisis , Fibrosis Quística/fisiopatología , Pulmón/fisiopatología , Neumonía/complicaciones , Esputo/química , Biomarcadores/análisis , Niño , Femenino , Humanos , Elastasa de Leucocito/metabolismo , Modelos Logísticos , Masculino , Estudios Prospectivos , Pruebas de Función Respiratoria , SueciaRESUMEN
BACKGROUND: Secretory leukocyte protease inhibitor (SLPI) is a protein with anti-protease and antimicrobial properties that is constitutively secreted from the airway epithelium. The importance of maintaining a balance between proteases and anti-proteases, and robust innate defence mechanisms in the airways, is exemplified by inflammatory lung conditions such as chronic obstructive pulmonary disease (COPD) and cystic fibrosis (CF). Both conditions present with a high protease burden in the airways which leads to tissue destruction. These patients also have an impaired innate immune system in the lungs with bacterial colonization and frequent airway infections. Moreover, both diseases are associated with airway hypoxia due to inflammation and mucus plugs. The aim of the present study was to investigate the role of hypoxia on SLPI production from the airway epithelium. METHODS: Primary human bronchial epithelial cells were grown in sub-immersed cultures or as differentiated epithelium in air liquid interface cultures. Cells were incubated at 21% O2 (normoxia) or 1% O2 (hypoxia), and the release of SLPI was analysed with ELISA. RT-PCR was used to study the expression of SLPI and transforming growth factor ß1 (TGF-ß1). RESULTS: Hypoxia decreased the constitutive production of SLPI by bronchial epithelial cells. The multifunctional cytokine TGF-ß1, which is known to affect SLPI expression, showed increased expression in hypoxic bronchial epithelial cells. When bronchial epithelial cells were exposed to exogenous TGF-ß1 during normoxia, the SLPI production was down-regulated. Addition of TGF-ß1-neutralizing antibodies partially restored SLPI production during hypoxia, showing that TGF-ß1 is an important regulator of SLPI during hypoxic conditions. CONCLUSIONS: The mechanism described here adds to our knowledge of the pathogenesis of severe pulmonary diseases associated with hypoxia, e.g. COPD and CF. The hypoxic down-regulation of SLPI may help explain the protease/anti-protease imbalance associated with these conditions and vulnerability to airway infections. Furthermore, it provides an interesting target for the treatment and prevention of exacerbation in these patients.
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Células Epiteliales/metabolismo , Hipoxia/genética , ARN Mensajero/metabolismo , Inhibidor Secretorio de Peptidasas Leucocitarias/genética , Factor de Crecimiento Transformador beta1/genética , Bronquios/citología , Bronquios/metabolismo , Regulación hacia Abajo , Ensayo de Inmunoadsorción Enzimática , Células Epiteliales/efectos de los fármacos , Regulación de la Expresión Génica , Humanos , Hipoxia/metabolismo , Elastasa de Leucocito/metabolismo , Reacción en Cadena en Tiempo Real de la Polimerasa , Mucosa Respiratoria/citología , Mucosa Respiratoria/metabolismo , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Inhibidor Secretorio de Peptidasas Leucocitarias/metabolismo , Factor de Crecimiento Transformador beta1/metabolismo , Factor de Crecimiento Transformador beta1/farmacologíaRESUMEN
BACKGROUND: Staphylococcus aureus bacteraemia (SAB) may lead to periprosthetic joint infections (PJI) via haematogenous spread of bacteria to the joint. Due to the risk of PJI, patients with SAB and prosthetic joint are recommended prolonged antibiotic treatment. The aim of the study was to assess the risk of PJI during SAB, and to evaluate if short treatment duration affects outcomes in patients with uncomplicated SAB and prosthetic joints without clinical signs of PJI. METHODS: Patients with growth of S. aureus in blood cultures were cross-referenced against the Swedish Arthroplasty register to identify patients with prosthetic hip or knee joints at the time of SAB. Medical records were reviewed to identify PJI at the time of SAB and during a 6-month follow-up period. RESULTS: Out of 400 patients with SAB and a prosthetic joint, 281 met all eligibility criteria and were included in the study. Of the included participants, 35 (12%) had a haematogenous PJI. Younger age and presence of multiple prosthetic joints were associated with an increased risk of PJI. Of the 247 patients without signs of PJI at the initial SAB episode, 118 patients (48%) had an uncomplicated infection and received short total antibiotic treatment (median 15 days, IQR 13-17). The risk of PJI during the follow-up period was low (<1%) and similar in the uncomplicated group compared to patients with complicated SAB that received longer antibiotic treatment (median 29 days, IQR 15-70). CONCLUSION: The prevalence of haematogenous PJI was lower than previously reported. Our data do not support prolonged antibiotic treatment in patients with SAB and prosthetic joints without clinical signs of PJI.
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BACKGROUND: The purpose of this study was to prospectively investigate the incidence of influenza-associated pulmonary aspergillosis (IAPA) in influenza patients admitted to intensive care units in Sweden. METHODS: The study included consecutive adult patients with PCR-verified influenza A or B in 12 Swedish intensive care units (ICUs) over four influenza seasons (2019-2023). Patients were screened using serum galactomannan and ß-d-glucan tests and fungal culture of a respiratory sample at inclusion and weekly during the ICU stay. Bronchoalveolar lavage was performed if clinically feasible. IAPA was classified according to recently proposed case definitions. RESULTS: The cohort included 55 patients; 42% were female, and the median age was 59 (IQR 48-71) years. All patients had at least one galactomannan test, ß-d-glucan test and respiratory culture performed. Bronchoalveolar lavage was performed in 24 (44%) of the patients. Five (9%, 95% CI 3.8% - 20.4%) patients were classified as probable IAPA, of which four lacked classical risk factors. The overall ICU mortality was significantly higher among IAPA patients than non-IAPA patients (60% vs 8%, p = 0.01). CONCLUSIONS: The study represents the first prospective investigation of IAPA incidence. The 9% incidence of IAPA confirms the increased risk of invasive pulmonary aspergillosis among influenza patients admitted to the ICU. Therefore, it appears reasonable to implement a screening protocol for the early diagnosis and treatment of IAPA in influenza patients receiving intensive care. TRIAL REGISTRATION: ClinicalTrials.gov NCT04172610, registered November 21, 2019.
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Aspergilosis , Gripe Humana , Femenino , Humanos , Masculino , Persona de Mediana Edad , Aspergillus , Glucanos , Gripe Humana/complicaciones , Gripe Humana/epidemiología , Unidades de Cuidados Intensivos , Estudios Prospectivos , Suecia/epidemiología , AncianoRESUMEN
BACKGROUND: Staphylococcus lugdunensis has been described as a pathogen of increasing importance in prosthetic joint infections (PJI). Our aim was to describe the clinical presentation of PJI caused by S. lugdunensis, and to correlate the biofilm-forming ability of the bacterial isolates to clinical outcome. METHOD: S. lugdunensis isolates from PJI episodes during 2015-2019 were included and analysed for biofilm formation using a microtiter plate assay. Medical records from the corresponding patients were reviewed. RESULTS: We identified 36 patients with PJI caused by S. lugdunensis during the study period. Early postoperative PJIs were most frequent (n = 20, 56%). Surgical intervention was performed in a majority of the patients (n = 33, 92%), and the dominating type of antibiotic treatment was a combination of rifampicin and ciprofloxacin (n = 27, 75%). The treatment success-rate was 81% (n = 29). All isolates causing PJI were able to form biofilm in vitro. Biofilm formation was significantly stronger in isolates causing relapsing vs non-relapsing PJI (mean OD550 3.1 ± 0.23 vs 1.14 ± 0.73 p = .001) and strong biofilm formation was also associated with late acute hematogenic PJI (mean OD550 1.8 ± 0.93 vs. 0.93 ± 0.81, p = .01). CONCLUSION: Strong biofilm production in S. lugdunensis isolates was associated with relapse in PJI.
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Artritis Infecciosa , Infecciones Relacionadas con Prótesis , Infecciones Estafilocócicas , Staphylococcus lugdunensis , Humanos , Infecciones Estafilocócicas/tratamiento farmacológico , Infecciones Estafilocócicas/microbiología , Antibacterianos/uso terapéutico , Biopelículas , Rifampin/uso terapéutico , Artritis Infecciosa/tratamiento farmacológico , Infecciones Relacionadas con Prótesis/tratamiento farmacológico , Infecciones Relacionadas con Prótesis/microbiologíaRESUMEN
Achromobacter is a genus of Gram-negative rods, which can cause persistent airway infections in people with cystic fibrosis (CF). The knowledge about virulence and clinical implications of Achromobacter is still limited, and it is not fully established whether Achromobacter infections contribute to disease progression or if it is a marker of poor lung function. The most commonly reported Achromobacter species in CF is A. xylosoxidans. While other Achromobacter spp. are also identified in CF airways, the currently used Matrix-Assisted Laser Desorption/Ionization Time Of Flight Mass Spectrometry (MALDI-TOF MS) method in routine diagnostics cannot distinguish between species. Differences in virulence between Achromobacter species have consequently not been well studied. In this study, we compare phenotypes and proinflammatory properties of A. xylosoxidans, A. dolens, A. insuavis, and A. ruhlandii using in vitro models. Bacterial supernatants were used to stimulate CF bronchial epithelial cells and whole blood from healthy individuals. Supernatants from the well-characterized CF-pathogen Pseudomonas aeruginosa were included for comparison. Inflammatory mediators were analyzed with ELISA and leukocyte activation was assessed using flow cytometry. The four Achromobacter species differed in morphology seen in scanning electron microscopy (SEM), but there were no observed differences in swimming motility or biofilm formation. Exoproducts from all Achromobacter species except A. insuavis caused significant IL-6 and IL-8 secretion from CF lung epithelium. The cytokine release was equivalent or stronger than the response induced by P. aeruginosa. All Achromobacter species activated neutrophils and monocytes ex vivo in a lipopolysaccharide (LPS)-independent manner. Our results indicate that exoproducts of the four included Achromobacter species do not differ consistently in causing inflammatory responses, but they are equally or even more capable of inducing inflammation compared with the classical CF pathogen P. aeruginosa. IMPORTANCE Achromobacter xylosoxidans is an emerging pathogen among people with cystic fibrosis (CF). Current routine diagnostic methods are often unable to distinguish A. xylosoxidans from other Achromobacter species, and the clinical relevance of different species is still unknown. In this work, we show that four different Achromobacter species relevant to CF evoke similar inflammatory responses from airway epithelium and leukocytes in vitro, but they are all equally or even more proinflammatory compared to the classic CF-pathogen Pseudomonas aeruginosa. The results suggest that Achromobacter species are important airway pathogens in CF, and that all Achromobacter species are relevant to treat.
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Achromobacter denitrificans , Achromobacter , Fibrosis Quística , Infecciones por Bacterias Gramnegativas , Humanos , Achromobacter/genética , Fibrosis Quística/complicaciones , Fibrosis Quística/microbiología , Infecciones por Bacterias Gramnegativas/microbiología , Achromobacter denitrificans/genética , PulmónRESUMEN
BACKGROUND: Achromobacter xylosoxidans is an emerging pathogen that causes airway infections in patients with cystic fibrosis. Knowledge of virulence factors and protein secretion systems in this bacterium is limited. Twin arginine translocation (Tat) is a protein secretion system that transports folded proteins across the inner cell membranes of gram-negative bacteria. Tat has been shown to be important for virulence and cellular processes in many different bacterial species. This study aimed to investigate the role of Tat in iron metabolism and host cell adhesion in A. xylosoxidans. METHODS: Putative Tat substrates in A. xylosoxidans were identified using the TatFind, TatP, and PRED-Tat prediction tools. An isogenic tatC deletion mutant (ΔtatC) was generated and phenotypically characterized. The wild-type and ΔtatC A. xylosoxidans were fractionated into cytosolic, membrane, and periplasmic fractions, and the expressed proteome of the different fractions was analyzed using liquid chromatography-mass spectrometry (LC-MS/MS). RESULTS: A total of 128 putative Tat substrates were identified in the A. xylosoxidans proteome. The ΔtatC mutant showed attenuated host cell adhesion, growth rate, and iron acquisition. Twenty predicted Tat substrates were identified as expressed proteins in the periplasmic compartment, nine of which were associated with the wild type. CONCLUSION: The data indicate that Tat secretion is important for iron acquisition and host cell adhesion in A. xylosoxidans.
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An increasing proportion of penicillin-susceptible Staphylococcus aureus (PSSA) has been reported over the last years. The aim of this retrospective study was to compare penicillin G with cloxacillin in the treatment of PSSA bloodstream infections. The primary outcome was the mortality rate after 90 days and the secondary outcome was the development of treatment complications of varying severity. Medical records from patients with PSSA bacteraemia during 2018-2020 were reviewed. Patient outcome was ranked on an ordinal scale according to severity: (i) alive at 90 days without any complications; (ii) adverse events not requiring treatment; (iii) change or addition of antibiotics owing to treatment failure or adverse events; (iv) relapse within 90 days; and (v) death within 90 days. The outcome ranking scale was dichotomised at every level and was analysed by logistic regression and a propensity score-weighted analysis. A total of 316 patients received cloxacillin and 68 patients received penicillin G as final treatment. Mortality rates did not differ significantly between the treatment groups (cloxacillin 19% vs. penicillin G 13%; P = 0.24), but patients treated with cloxacillin had an increased odds of having any complication compared with patients treated with penicillin G (odds ratio = 2.43, 95% confidence interval 1.30-4.53; P = 0.005). A propensity score analysis confirmed the results. Mortality rates in PSSA bacteraemia did not differ between treatment groups but cloxacillin treatment increased the overall odds of treatment complications.
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Bacteriemia , Infecciones Estafilocócicas , Antibacterianos/uso terapéutico , Bacteriemia/tratamiento farmacológico , Cloxacilina/uso terapéutico , Humanos , Penicilina G , Penicilinas/efectos adversos , Estudios Retrospectivos , Infecciones Estafilocócicas/tratamiento farmacológico , Staphylococcus aureus , Resultado del TratamientoRESUMEN
BACKGROUND: Disturbance in the oropharyngeal microbiota is common in hospitalized patients and contributes to the development of nosocomial pneumonia. Lactiplantibacillus plantarum 299 and 299v (Lp299 and Lp299v) are probiotic bacteria with beneficial effects on the human microbiome. AIM: To investigate how Lp299 and Lp299v affect the growth of nosocomial oropharyngeal pathogens in vitro and to evaluate the efficacy in vivo when these probiotics are administered prophylactically in hospitalized patients. METHODS: The in vitro effect of Lp299 and Lp299v on nosocomial respiratory tract pathogens was evaluated using two methods, the co-culture and agar overlay. In the clinical study, patients were randomized to orally receive either probiotics or placebo twice daily during their hospital stay. Oropharyngeal swabs were analyzed at inclusion and every fourth day throughout hospitalization. FINDINGS: All tested pathogens were completely inhibited by both Lp299 and Lp299v using the agar-overlay method. In the co-culture experiment, Lp299 and Lp299v significantly (p < 0.05) reduced the growth of all pathogens except for Enterococcus faecalis co-incubated with Lp299. In the clinical study, daily oral treatment with Lp299 and Lp299v did not influence the development of disturbed oropharyngeal microbiota or nosocomial infection. Proton pump inhibitors, antibiotics, and steroid treatment were identified as risk factors for developing disturbed oropharyngeal microbiota. CONCLUSIONS: Lp299 and Lp299v inhibited pathogen growth in vitro but did not affect the oropharyngeal microbiota in vivo. The ClinicalTrials.gov Identifier for this study is NCT02303301.
Asunto(s)
Antibacterianos/uso terapéutico , Bacterias/crecimiento & desarrollo , Infección Hospitalaria/terapia , Lactobacillus plantarum/metabolismo , Probióticos/uso terapéutico , Infecciones del Sistema Respiratorio/terapia , Adulto , Anciano , Anciano de 80 o más Años , Antibiosis/fisiología , Femenino , Humanos , Masculino , Microbiota/efectos de los fármacos , Persona de Mediana Edad , Orofaringe/microbiología , Placebos/administración & dosificación , Infecciones del Sistema Respiratorio/microbiología , Adulto JovenRESUMEN
Bacterial pathogens evolve during chronic colonization of the human host by selection for pathoadaptive mutations. One of the emerging and understudied bacterial species causing chronic airway infections in patients with cystic fibrosis (CF) is Achromobacter xylosoxidans. It can establish chronic infections in patients with CF, but the genetic and phenotypic changes associated with adaptation during these infections are not completely understood. In this study, we analyzed the whole-genome sequences of 55 clinical A. xylosoxidans isolates longitudinally collected from the sputum of 6 patients with CF. Four genes encoding regulatory proteins and two intergenic regions showed convergent evolution, likely driven by positive selection for pathoadaptive mutations, across the different clones of A. xylosoxidans. Most of the evolved isolates had lower swimming motility and were resistant to multiple classes of antibiotics, while fewer of the evolved isolates had slower growth or higher biofilm production than the first isolates. Using a genome-wide association study method, we identified several putative genetic determinants of biofilm formation, motility and ß-lactam resistance in this pathogen. With respect to antibiotic resistance, we discovered that a combination of mutations in pathoadaptive genes (phoQ and bigR) and two other genes encoding regulatory proteins (spoT and cpxA) were associated with increased resistance to meropenem and ceftazidime. Altogether, our results suggest that genetic changes within regulatory loci facilitate within-host adaptation of A. xylosoxidans and the emergence of adaptive phenotypes, such as antibiotic resistance or biofilm formation. IMPORTANCE A thorough understanding of bacterial pathogen adaptation is essential for the treatment of chronic bacterial infections. One unique challenge in the analysis and interpretation of genomics data is identifying the functional impact of mutations accumulated in the bacterial genome during colonization in the human host. Here, we investigated the genomic and phenotypic evolution of A. xylosoxidans in chronic airway infections of patients with CF and identified several mutations associated with the phenotypic evolution of this pathogen using genome-wide associations. Identification of phenotypes under positive selection and the associated mutations can enlighten the adaptive processes of this emerging pathogen in human infections and pave the way for novel therapeutic interventions.
RESUMEN
BACKGROUND: Autoantibodies to bactericidal/permeability-increasing protein (BPI), BPI-ANCA, are often present in serum of patients with cystic fibrosis (CF), and correlate to airway colonization with Pseudomonas aeruginosa. The aim of the study was to investigate if BPI-ANCA IgA is also present in the airways of CF patients, and if its presence correlates with neutrophil counts, platelets, and P. aeruginosa DNA in sputum. METHODS: BPI-ANCA IgA was quantified in serum and sputum samples from adult CF patients (n = 45) by ELISA. Sputum neutrophil counts, platelets, and platelet-neutrophil complexes were assessed by flow cytometry, and P. aeruginosa DNA was analysed with RT-PCR. RESULTS: Serum BPI-ANCA IgA was present in 44% of the study participants, and this group also had significantly enhanced BPI-ANCA levels in sputum compared to serum negative patients. Sputum levels of BPI-ANCA IgA correlated with P. aeruginosa DNA (r = 0.63, p = 0.0003) and platelet counts in sputum (r = 0.60, p = 0.0002). CONCLUSIONS: BPI-ANCA is expressed in the airways of CF patients and correlates with P. aeruginosa load and platelet counts, suggesting a link to airway inflammation and mucosal immunity.
Asunto(s)
Anticuerpos Anticitoplasma de Neutrófilos/metabolismo , Péptidos Catiónicos Antimicrobianos/inmunología , Péptidos Catiónicos Antimicrobianos/metabolismo , Proteínas Sanguíneas/inmunología , Proteínas Sanguíneas/metabolismo , Fibrosis Quística/metabolismo , Fibrosis Quística/microbiología , Recuento de Plaquetas , Pseudomonas aeruginosa , Sistema Respiratorio/inmunología , Sistema Respiratorio/microbiología , Esputo/inmunología , Esputo/microbiología , Adulto , Recuento de Colonia Microbiana , Fibrosis Quística/inmunología , ADN Bacteriano/metabolismo , Femenino , Humanos , Inmunoglobulina A/metabolismo , Inflamación , Recuento de Leucocitos , Masculino , Neutrófilos , Pseudomonas aeruginosa/genética , Sistema Respiratorio/citología , Sistema Respiratorio/metabolismo , Esputo/citología , Esputo/metabolismoRESUMEN
Antimicrobial peptides are important players of the innate host defence against invading microorganisms. The aim of this study was to evaluate the activity of airway antimicrobial peptides against the common cystic fibrosis (CF) pathogen Pseudomonas aeruginosa, and to compare it to the emerging multi-drug resistant CF pathogens Achromobacter xylosoxidans and Stenotrophomonas maltophilia. Clinical bacterial isolates from CF patients were used, and the antimicrobial activity of human beta-defensin 2 and 3, LL37 and lysozyme was evaluated using radial diffusion assay and viable counts. The cell surface zeta potential was analysed to estimate the net charge at the bacterial surface. Of the bacterial species included in the study, A. xylosoxidans was the most resistant to antimicrobial peptides, whereas P. aeruginosa was the most susceptible. The net charge of the bacterial surface was significantly more negative for P. aeruginosa compared to A. xylosoxidans, which may in part explain the differences in susceptibility.