Severe Community-Acquired Bloodstream Infection with Acinetobacter ursingii in Person who Injects Drugs.
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ABSTRACT:
SUBMITTER: Salzer HJ
PROVIDER: S-EPMC4696709 | biostudies-literature |
REPOSITORIES: biostudies-literature
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Project description:Acinetobacter ursingii has not been reported in infectious processes apart from its recent description as a new species. A bacteremia caused by A. ursingii in a patient with a pulmonary adenocarcinoma confirms that this microorganism is an opportunistic human pathogen. The isolate was susceptible to imipenem, aminoglycosides, rifampin, and fluoroquinolones.
| S-EPMC150291 | biostudies-literature
Project description:ObjectivesSARS-CoV-2 may cause acute lung injury, and secondary infections are thus relevant complications in patients with COVID-19 pneumonia. However, detailed information on community- and hospital-acquired infections among patients with COVID-19 pneumonia is scarce.MethodsWe identified 220 SARS-CoV-2-positive patients hospitalized at the University Hospital Basel, Switzerland (between 25 February and 31 May 2020). We excluded patients who declined the general consent (n = 12), patients without clinical evidence of pneumonia (n = 29), and patients hospitalized for < 24 h (n = 17). We evaluated the frequency of community- and hospital-acquired infections using respiratory and blood culture materials with antigen, culture-based, and molecular diagnostics. For ICU patients, all clinical and microbial findings were re-evaluated interdisciplinary (intensive care, infectious disease, and clinical microbiology), and agreement reached to classify patients with infections.ResultsIn the final cohort of 162 hospitalized patients (median age 64.4 years (IQR, 50.4-74.2); 61.1% male), 41 (25.3%) patients were admitted to the intensive care unit, 34/41 (82.9%) required mechanical ventilation, and 17 (10.5%) of all hospitalized patients died. In total, 31 infections were diagnosed including five viral co-infections, 24 bacterial infections, and three fungal infections (ventilator-associated pneumonia, n = 5; tracheobronchitis, n = 13; pneumonia, n = 1; and bloodstream infection, n = 6). Median time to respiratory tract infection was 12.5 days (IQR, 8-18) and time to bloodstream infection 14 days (IQR, 6-30). Hospital-acquired bacterial and fungal infections were more frequent among ICU patients than other patients (36.6% vs. 1.7%). Antibiotic or antifungal treatment was administered in 71 (43.8%) patients.ConclusionsCommunity-acquired viral and bacterial infections were rare among COVID-19 pneumonia patients. By contrast, hospital-acquired bacterial or fungal infections were frequently complicating the course among ICU patients.
| S-EPMC7812551 | biostudies-literature
Project description:Acinetobacter baumannii causes severe, fulminant, community-acquired pneumonia (CAP) in tropical and subtropical regions. We compared the population structure, virulence and antimicrobial resistance determinants of northern Australian community-onset A. baumannii strains with local and global strains. We performed whole-genome sequencing on 55 clinical and five throat colonization A. baumannii isolates collected in northern Australia between 1994 and 2016. Clinical isolates included CAP (n=41), healthcare-associated pneumonia (n=7) and nosocomial bloodstream (n=7) isolates. We also included 93 publicly available international A. baumannii genome sequences in the analyses. Patients with A. baumannii CAP were almost all critically unwell; 82 % required intensive care unit admission and 18 % died during their inpatient stay. Whole-genome phylogenetic analysis demonstrated that community-onset strains were not phylogenetically distinct from nosocomial strains. Some non-multidrug-resistant local strains were closely related to multidrug-resistant strains from geographically distant locations. Pasteur sequence type (ST)10 was the dominant ST and accounted for 31/60 (52 %) northern Australian strains; the remainder belonged to a diverse range of STs. The most recent common ancestor for ST10 was estimated to have occurred in 1738 (95 % highest posterior density, 1626-1826), with evidence of multiple introduction events between Australia and Southeast Asia between then and the present day. Virulence genes associated with biofilm formation and the type 6 secretion system (T6SS) were absent in many strains, and were not associated with in-hospital mortality. All strains were susceptible to gentamicin and meropenem; none carried an AbaR resistance island. Our results suggest that international dissemination of A. baumannii is occurring in the community on a contemporary timescale. Genes associated with biofilm formation and the T6SS may not be required for survival in community niches. The relative contributions of host and bacterial factors to the clinical severity of community-onset A. baumannii infection require further investigation.
| S-EPMC6487312 | biostudies-literature
Project description:BackgroundThe epidemiology of bloodstream infection (BSI) is well-established; however, little is known about the contribution of different pathogens to mortality. To understand true burden of BSI, pathogens contributing to mortality were investigated and compared according to where the BSI was acquired.MethodsData from deceased patients in two teaching hospitals in the Republic of Korea were collected. BSI contributing mortality was defined as BSI within 2-weeks before death. Cases were grouped by acquisition sites: community-acquired (CA)-, healthcare-associated (HCA)-, and hospital-acquired (HA)-BSI. Drug resistance, BSI focus, and appropriateness of empirical antimicrobial therapy were also compared.ResultsAmong 1849 deceased patients in the hospitals, 280 (15.1%) patients experienced BSI within 2-weeks before death. In all, 71, 53, and 156 patients in the CA-, HCA-, and HA-BSI groups, respectively, with 316 total isolated pathogens were analyzed. The three most common pathogens were Klebsiella pneumoniae (17.1%), Escherichia coli (16.4%), and Staphylococcus aureus (11.4%). While K. pneumoniae and E. coli were the most common pathogens in CA- and HCA-BSI, Acinetobacter baumannii and Candida species were in HA-BSI. 26.3% (41/156) of patients experienced breakthrough HCA-BSI during administration of carbapenem and/or vancomycin. The proportion of central venous catheter-related infection (0%, 3.4% and 28.3%), carbapenem resistant-Gram negative bacilli (0%, 6.9% and 21.9%), and inappropriate empirical antimicrobial therapy (21.1%, 37.7% and 51.9%; all P < 0.001) were more frequently observed in HA-BSI.ConclusionThe epidemiology of BSI related to mortality had unique characteristics according to the acquisition site. Given the epidemiology of HA-BSI, infection control and antibiotics stewardship programs should be emphasized.
| S-EPMC8981700 | biostudies-literature
Project description:We describe the first case of community-acquired bacteremia caused by Acinetobacter radioresistens; the patient was a 32-year-old HIV-positive neutropenic woman. Ambiguous Gram staining and poor biochemical reactivity of blood culture isolates misguided early diagnosis and therapy. Bacterial identification was based on 16S rDNA sequence analysis. A. radioresistens can be considered as a cause of opportunistic infection in immunodeficient patients.
| S-EPMC2631918 | biostudies-other
Project description:With the expanding use of molecular assays, viral pathogens are increasingly recognized among critically ill adult patients with community-acquired severe respiratory illness; studies have detected respiratory viral infections (RVIs) in 17-53% of such patients. In addition, novel pathogens including zoonotic coronaviruses like the agents causing Severe Acute Respiratory Syndrome (SARS), Middle East Respiratory Syndrome (MERS) and the 2019 novel coronavirus (2019 nCoV) are still being identified. Patients with severe RVIs requiring ICU care present typically with hypoxemic respiratory failure. Oseltamivir is the most widely used neuraminidase inhibitor for treatment of influenza; data suggest that early use is associated with reduced mortality in critically ill patients with influenza. At present, there are no antiviral therapies of proven efficacy for other severe RVIs. Several adjunctive pharmacologic interventions have been studied for their immunomodulatory effects, including macrolides, corticosteroids, cyclooxygenase-2 inhibitors, sirolimus, statins, anti-influenza immune plasma, and vitamin C, but none is recommended at present in severe RVIs. Evidence-based supportive care is the mainstay for management of severe respiratory viral infection. Non-invasive ventilation in patients with severe RVI causing acute hypoxemic respiratory failure and pneumonia is associated with a high likelihood of transition to invasive ventilation. Limited existing knowledge highlights the need for data regarding supportive care and adjunctive pharmacologic therapy that is specific for critically ill patients with severe RVI. There is a need for more pragmatic and efficient designs to test different therapeutics both individually and in combination.
| S-EPMC7079862 | biostudies-literature
Project description:BACKGROUND:Acinetobacter baumannii is a gram-negative aerobic bacillus that is commonly causes of hospital-acquired infections. Community-acquired pneumonia caused by Acinetobacter baumannii (CAP-Ab) is rare but fatal if diagnosis and treatment are delayed. Conventional culture of clinical specimens is the main method for clinical diagnosis of A. baumannii infections which may suffer from limited positive rate and is time consuming. Timely and precise diagnosis of CAP-Ab remains challenging. CASE PRESENTATION:A 66-year-old man with 24?h history of acute fever and dyspnea was admitted to our hospital. He was diagnosed as severe community acquired pneumonia (CAP), septic shock, respiratory failure and acute kidney injury. Next-generation sequencing (NGS) was performed on the patient's sputum and blood, which identified numerous A. baumannii nucleotide sequences in the sample of sputum and led to the rapid diagnosis and treatment of community acquired pneumonia caused by A. baumannii. This result was confirmed by subsequent sputum culture. CONCLUSIONS:This case described that the successful application of the next generation sequencing assisting the speedy diagnosis of A. baumannii infection provides a new idea for the timely diagnosis of CAP-Ab and highlights that NGS is a promising tool in rapid etiological diagnosis of acute and severe infectious diseases.
| S-EPMC6964051 | biostudies-literature
Project description:BACKGROUND:Community acquired bloodstream infection (CABSI) in low- and middle income countries is associated with a high mortality. This study describes the clinical manifestations, laboratory findings and correlation of SOFA and qSOFA with mortality in patients with CABSI in northern Vietnam. METHODS:This was a retrospective study of 393 patients with at least one positive blood culture with not more than one bacterium taken within 48 h of hospitalisation. Clinical characteristic and laboratory results from the first 24 h in hospital were collected. SOFA and qSOFA scores were calculated and their validity in this setting was evaluated. RESULTS:Among 393 patients with bacterial CABSI, approximately 80% (307/393) of patients had dysfunction of one or more organ on admission to the study hospital with the most common being that of coagulation (57.1% or 226/393). SOFA performed well in prediction of mortality in those patients initially admitted to the critical care unit (AUC 0.858, 95%CI 0.793-0.922) but poor in those admitted to medical wards (AUC 0.667, 95%CI 0.577-0.758). In contrast qSOFA had poor predictive validity in both settings (AUC 0.692, 95%CI 0.605-0.780 and AUC 0.527, 95%CI 0.424-0.630, respectively). The overall case fatality rate was 28%. HIV infection (HR?=?3.145, p =?0.001), neutropenia (HR?=?2.442, p =?0.002), SOFA score 1-point increment (HR?=?1.19, p <?0.001) and infection with Enterobacteriaceae (HR?=?1.722, p =?0.037) were independent risk factors for in-hospital mortality. CONCLUSIONS:Organ dysfunction was common among Vietnamese patients with CABSI and associated with high case fatality. SOFA and qSOFA both need to be further validated in this setting.
| S-EPMC6204014 | biostudies-literature
Project description:Acinetobacter baumannii is emerging as a leading global multiple-antibiotic-resistant nosocomial pathogen. The identity of genes essential for pathogenesis in a mammalian host remains largely unknown. Using transposon-directed insertion-site sequencing (TraDIS), we identified A. baumannii genes involved in bacterial survival in a leukopenic mouse model of bloodstream infection. Mice were inoculated with a pooled transposon mutant library derived from 109,000 mutants, and TraDIS was used to map transposon insertion sites in the genomes of bacteria in the inoculum and of bacteria recovered from mouse spleens. Unique transposon insertion sites were mapped and used to calculate a fitness factor for every insertion site based on its relative abundance in the inoculum and postinfection libraries. Eighty-nine transposon insertion mutants that were underrepresented after experimental infection in mice compared to their presence in the inocula were delineated as candidates for further evaluation. Genetically defined mutants lacking feoB (ferrous iron import), ddc (d-ala-d-ala-carboxypeptidase), and pntB (pyridine nucleotide transhydrogenase subunit) exhibited a fitness defect during systemic infection resulting from bacteremia. In vitro, these mutants, as well as a fepA (ferric enterobactin receptor) mutant, are defective in survival in human serum and within macrophages and are hypersensitive to killing by antimicrobial peptides compared to the survival of the parental strain under these conditions. Our data demonstrate that FepA is involved in the uptake of exogenous enterobactin in A. baumannii. Genetic complementation rescues the phenotypes of mutants in assays that emulate conditions encountered during infection. In summary, we have determined novel A. baumannii fitness genes involved in the pathogenesis of mammalian infection. IMPORTANCE A. baumannii is a significant cause of bacterial bloodstream infection in humans. Since multiple antibiotic resistance is becoming more common among strains of A. baumannii, there is an urgent need to develop novel tools to treat infections caused by this dangerous pathogen. To develop knowledge-guided treatment approaches for A. baumannii, a thorough understanding of the mechanism by which this pathogen causes bloodstream infection is required. Here, using a mouse model of infection, we report the identification of A. baumannii genes that are critical for the ability of this pathogen to cause bloodstream infections. This study lays the foundation for future research on A. baumannii genes that can be targeted to develop novel therapeutics against this emerging human pathogen.
| S-EPMC4863628 | biostudies-literature
