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Søgeord (legionella) valgt.
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Sarah MichaelisLaura Gomez-ValeroTong ChenCamille SchmidCarmen BuchrieserHubert Hilbi1Institute of Medical Microbiology, University of Zürich, Zürich, Switzerland2Institut Pasteur, Université de Paris, Unité Biologie des Bactéries Intracellulaires, Paris, FranceCorrella S. Detweiler
Microbiology and Molecular Biology Reviews, 21.08.2024
Tilføjet 21.08.2024
FEMS Microbiology Reviews, 2.08.2024
Tilføjet 2.08.2024
Abstract Interactions between eukaryotic hosts and their bacterial symbionts drive key ecological and evolutionary processes, from regulating ecosystems to the evolution of complex molecular machines and processes. Over time, endosymbionts generally evolve reduced genomes, and their relationship with their host tends to stabilize. However, host-bacteria relationships may be heavily influenced by environmental changes. Here, we review these effects on one of the most ancient and diverse endosymbiotic groups, formed by - among others - Legionellales, Francisellaceae, and Piscirickettsiaceae. This group is referred to as Deep-branching Intracellular Gammaproteobacteria (DIG), whose last common ancestor presumably emerged about 2 Ga ago. We show that DIGs are globally distributed, but generally very lowly abundant, and are mainly identified in aquatic biomes. Most DIGs harbor a type IVB secretion system, critical for host-adaptation, but its structure and composition vary. Finally, we review the different types of microbial interactions that can occur in diverse environments, with direct or indirect effects on DIG populations. The increased use of omics technologies on environmental samples will allow a better understanding of host-bacterial interactions and help unravel the definition of DIG as a group from an ecological, molecular and evolutionary perspective.
Læs mere Tjek på PubMedBMC Infectious Diseases, 23.04.2024
Tilføjet 23.04.2024
Abstract Background Severe acute respiratory infection (SARI), a significant global health concern, imposes a substantial disease burden. In China, there is inadequate data concerning the monitoring of respiratory pathogens, particularly bacteria, among patients with SARI. Therefore, this study aims to delineate the demographic, epidemiological, and aetiological characteristics of hospitalised SARI patients in Central China between 2018 and 2020. Methods Eligible patients with SARI admitted to the First Affiliated Hospital of Zhengzhou University between 1 January 2018 and 31 December 2020 were included in this retrospective study. Within the first 24 h of admission, respiratory (including sputum, nasal/throat swabs, bronchoalveolar lavage fluid, thoracocentesis fluid, etc.), urine, and peripheral blood specimens were collected for viral and bacterial testing. A multiplex real-time polymerase chain reaction (PCR) diagnostic approach was used to identify human influenza virus, respiratory syncytial virus, parainfluenza virus, adenovirus, human bocavirus, human coronavirus, human metapneumovirus, and rhinovirus. Bacterial cultures of respiratory specimens were performed with a particular focus on pathogenic microorganisms, including S. pneumoniae, S. aureus, K. pneumoniae, P. aeruginosa, Strep A, H. influenzae, A. baumannii, and E. coli. In cases where bacterial culture results were negative, nucleic acid extraction was performed for PCR to assay for the above-mentioned eight bacteria, as well as L. pneumophila and M. pneumoniae. Additionally, urine specimens were exclusively used to detect Legionella antigens. Furthermore, epidemiological, demographic, and clinical data were obtained from electronic medical records. Results The study encompassed 1266 patients, with a mean age of 54 years, among whom 61.6% (780/1266) were males, 61.4% (778/1266) were farmers, and 88.8% (1124/1266) sought medical treatment in 2020. Moreover, 80.3% (1017/1266) were housed in general wards. The most common respiratory symptoms included fever (86.8%, 1122/1266) and cough (77.8%, 986/1266). Chest imaging anomalies were detected in 62.6% (792/1266) of cases, and 58.1% (736/1266) exhibited at least one respiratory pathogen, with 28.5% (361/1266) having multiple infections. Additionally, 95.7% (1212/1266) of the patients were from Henan Province, with the highest proportion (38.3%, 486/1266) falling in the 61–80 years age bracket, predominantly (79.8%, 1010/1266) seeking medical aid in summer and autumn. Bacterial detection rate (39.0%, 495/1266) was higher than viral detection rate (36.9%, 468/1266), with the primary pathogens being influenza virus (13.8%, 175/1266), K. pneumoniae (10.0%, 127/1266), S. pneumoniae (10.0%, 127/1266), adenovirus (8.2%, 105/1266), P. aeruginosa (8.2%, 105/1266), M. pneumoniae (7.8%, 100/1266), and respiratory syncytial virus (7.7%, 98/1266). During spring and winter, there was a significant prevalence of influenza virus and human coronavirus, contrasting with the dominance of parainfluenza viruses in summer and autumn. Respiratory syncytial virus and rhinovirus exhibited higher prevalence across spring, summer, and winter. P. aeruginosa, K. pneumoniae, and M. pneumoniae were identified at similar rates throughout all seasons without distinct spikes in prevalence. However, S. pneumoniae showed a distinctive pattern with a prevalence that doubled during summer and winter. Moreover, the positive detection rates of various other viruses and bacteria were lower, displaying a comparatively erratic prevalence trend. Among patients admitted to the intensive care unit, the predominant nosocomial bacteria were K. pneumoniae (17.2%, 43/249), A. baumannii (13.6%, 34/249), and P. aeruginosa (12.4%, 31/249). Conversely, in patients from general wards, predominant pathogens included influenza virus (14.8%, 151/1017), S. pneumoniae (10.4%, 106/1017), and adenovirus (9.3%, 95/1017). Additionally, paediatric patients exhibited significantly higher positive detection rates for influenza virus (23.9%, 11/46) and M. pneumoniae (32.6%, 15/46) compared to adults and the elderly. Furthermore, adenovirus (10.0%, 67/669) and rhinovirus (6.4%, 43/669) were the primary pathogens in adults, while K. pneumoniae (11.8%, 65/551) and A. baumannii (7.1%, 39/551) prevailed among the elderly, indicating significant differences among the three age groups. Discussion In Central China, among patients with SARI, the prevailing viruses included influenza virus, adenovirus, and respiratory syncytial virus. Among bacteria, K. pneumoniae, S. pneumoniae, P. aeruginosa, and M. pneumoniae were frequently identified, with multiple infections being very common. Additionally, there were substantial variations in the pathogen spectrum compositions concerning wards and age groups among patients. Consequently, this study holds promise in offering insights to the government for developing strategies aimed at preventing and managing respiratory infectious diseases effectively.
Læs mere Tjek på PubMedM. Rigter, S.E. van Roeden, R. Barth, M. Wegdam-Blans
Clinical Microbiology and Infection, 6.04.2024
Tilføjet 6.04.2024
Amongst hospitalized CAP patients in the Netherlands, atypical pathogens were identified in 0-30%, with variation depending on season, selection of patient population and type of ward. (1) Molecular tests play a crucial role in the diagnostic field of atypical respiratory pathogens (Chlamydia pneumoniae, Chlamydia psittaci, Coxiella burnetii, Legionella pneumophila and Mycoplasma pneumoniae), since they are typically not detected with standard diagnostic methods. (2) Polymerase chain reactions (PCRs) targeting these pathogens are frequently requested in the three academic hospitals served by our microbiological facility (University Medical Center Utrecht (adult tertiary facility), Wilhelmina Children\'s Hospital (pediatric tertiary facility) and Princess Maxima Center (pediatric oncological facility), but the yield and clinical consequences of these diagnostics in daily practice are unclear.
Læs mere Tjek på PubMedMinjia ChenXiuqin CaoRonghui ZhengHaixia ChenRuixia HeHao ZhouZhiwei Yanga Department of Pathogenic Biology and Medical Immunology, School of Basic Medicine, Ningxia Medical University, Yinchuan, Chinab Key Laboratory of Fertility Preservation and Maintenance, Ministry of Education, School of Basic Medicine, Ningxia Medical University, Yinchuan, China
Virulence, 3.04.2024
Tilføjet 3.04.2024