The human respiratory tract is constantly exposed to a wide variety of viruses, microbes and inorganic particulates from environmental air, water and food. Physical characteristics of inhaled particles and airway mucosal immunity determine which viruses and microbes will persist in the airways. Here we present the first metagenomic study of DNA viral communities in the airways of diseased and non-diseased individuals. We obtained sequences from sputum DNA viral communities in 5 individuals with cystic fibrosis (CF) and 5 individuals without the disease. Overall, diversity of viruses in the airways was low, with an average richness of 175 distinct viral genotypes. The majority of viral diversity was uncharacterized. CF phage communities were highly similar to each other, whereas Non-CF individuals had more distinct phage communities, which may reflect organisms in inhaled air. CF eukaryotic viral communities were dominated by a few viruses, including human herpesviruses and retroviruses. Functional metagenomics showed that all Non-CF viromes were similar, and that CF viromes were enriched in aromatic amino acid metabolism. The CF metagenomes occupied two different metabolic states, probably reflecting different disease states. There was one outlying CF virome which was characterized by an over-representation of Guanosine-5′-triphosphate,3′-diphosphate pyrophosphatase, an enzyme involved in the bacterial stringent response. Unique environments like the CF airway can drive functional adaptations, leading to shifts in metabolic profiles. These results have important clinical implications for CF, indicating that therapeutic measures may be more effective if used to change the respiratory environment, as opposed to shifting the taxonomic composition of resident microbiota.
Bacteriophage Recombineering of Electroporated DNA (BRED) has been described for construction of gene deletion and point mutations in mycobacteriophages. Using BRED, we inserted a Phsp60-egfp cassette (1143 bp) into the mycobacteriophage D29 genome to construct a new reporter phage, which was used for detection of mycobacterial cells. The cassette was successfully inserted and recombinant mycobacteriophage purified. DNA sequencing of the cassette did not show any mutations even after several phage generations. Mycobacterium smegmatis mc(2) 155 cells were infected with D29::Phsp60-egfp (MOI of 10) and evaluated for EGFP expression by microscopy. Fluorescence was observed at around 2 h after infection, but dissipated in later times because of cell lysis. We attempted to construct a lysis-defective mutant by deleting the lysA gene, although we were unable to purify the mutant to homogeneity even with complementation. These observations demonstrate the ability of BRED to insert c. 1 kbp-sized DNA segments into mycobacteriophage genomes as a strategy for constructing new diagnostic reporter phages.
Introduction. Mycobacterium abscessus is an emerging pulmonary pathogen with limited treatment options. Nitric oxide (NO) demonstrates antibacterial activity against various bacterial species, including mycobacteria. In this study, we evaluated the effect of adjunctive inhaled NO therapy, using a novel NO generator, in a CF patient with pulmonary M. abscessus disease, and examined heterogeneity of response to NO in vitro. Methods. In the compassionate-use treatment, a 24-year-old CF patient with pulmonary M. abscessus was treated with two courses of adjunctive intermittent NO, first at 160 p.p.m. for 21 days and subsequently by escalating the dose up to 240 p.p.m. for 8 days. Methemoglobin, pulmonary function, 6 min walk distance (6MWD), qualify of life and sputum microbiology were assessed. In vitro susceptibility tests were performed against patient’s isolate and comparison clinical isolates and quantified by Hill’s slopes calculated from time–kill curves. Results. M. abscessus lung infection eradication was not achieved, but improvements in selected qualify of life domains, lung function and 6MWD were observed during the study. Inhaled NO was well tolerated at 160 p.p.m. Dosing at 240 p.p.m. was stopped due to adverse symptoms, although methemoglobin levels remained within safety thresholds. In vitro susceptibility tests showed a dose-dependent NO effect on M. abscessus susceptibility and significant heterogeneity in response between M. abscessus clinical isolates. The patient’s isolate was found to be the least susceptible strain in vitro. Conclusion. These results demonstrate heterogeneity in M. abscessus susceptibility to NO and suggest that longer treatment regimens could be required to see the reduction or eradication of more resistant pulmonary strains.
CONTEXT AND OBJECTIVE: Staphylococcus aureus is the most frequent agent isolated in diabetic foot infections and may be associated with changes to wound healing times. The aim of this study was to perform a systematic review of the literature, including studies that assessed the efficacy of any clinical or surgical intervention, as well as oral or topical therapy for diabetic ulcers infected with S. aureus. DESIGN AND SETTING:Systematic review with a search conducted in databases. METHODS:We conducted a systematic review with a comprehensive search in the Lilacs, SciELO, PubMed/Medline, Old Medline, Embase and Cochrane Library databases, for articles published from 1966 to 2010. The articles selected were limited to studies on diabetic patients with wounds infected with S. aureus for whom their healing was followed up, with the use of either antibiotics or experimental treatments. Animal studies and those that did not report the wound healing, as well as review articles, were excluded. RESULTS:Five studies that met the inclusion and exclusion criteria were analyzed. CONCLUSIONS:There are few studies reporting the healing of wounds infected with S. aureus in diabetic patients, although this is the most commonly found pathogen in this type of wound and it frequently consists of methicillin-resistant S. aureus (MRSA). There is insufficient evidence to support early use of broad-spectrum antibiotics against MRSA to promote healing of diabetic ulcers, since antibiotic resistance may develop from such treatment.This highlights the need for further studies on the subject. RESUMOCONTEXTO: Staphylococcus aureus é o agente mais frequentemente isolado nas infecções de pé em pacientes diabéticos e pode estar associado a mudança no tempo de cicatrização de feridas. O objetivo deste estudo foi realizar uma revisão sistemática da literatura, incluindo estudos que avaliaram a eficácia de qualquer intervenção clínica, cirúrgica, bem como terapia oral ou tópica para o tratamento de úlceras diabéticas infectadas com o S. aureus. TIPO DE ESTUDO E LOCAL:Revisão sistemática com busca realizada em bancos de dados. MÉTODOS:Realizamos uma revisão sistemática com uma busca abrangente nos bancos de dados Lilacs, SciELO, PubMed/Medline, Old Medline, Embase e no banco de dados da biblioteca Cochrane, publicados entre 1966 e 2010. Os artigos selecionados foram limitados aos estudos com feridas infectadas por S. aureus de pacientes diabéticos, que tiveram cicatrização relatada, quer pela utilização de antibióticos ou por substâncias experimentais. Foram excluídos os estudos com animais e os que não relataram a cicatrização das feridas, bem como artigos de revisão. RESULTADOS:Foram analisados cinco estudos que obedeceram aos critérios de inclusão e exclusão.CONCLUSÕES: Raros estudos relataram cicatrização de feridas infectadas com S. aureus em pacientes diabéticos, embora este seja o patógeno mais comumente encontrado neste tipo de ferida, sendo frequentemente resistente à meticilina MRSA (methicillin-resistant S. aureus). Não há evidê...
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
customersupport@researchsolutions.com
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
This site is protected by reCAPTCHA and the Google Privacy Policy and Terms of Service apply.
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.