Conventional identification of Aeromonas species based on biochemical methods is challenged by the heterogeneous nature of the species. Here, we present a new multiplex PCR method directed toward the gyrB and rpoB genes that identifies four Aeromonas species, A. hydrophila, A. media, A. veronii, and A. caviae, and we describe the application of this method on a Danish strain collection.A eromonas spp. are highly adapted to aquatic environments and have been described as pathogenic to humans and animals. The genus Aeromonas consists of more than 20 valid species, of which A. hydrophila, A. caviae (synonymous with A. punctata), A. media, A. veronii bv. sobria, and A. veronii bv. veronii are of particular clinical significance, because they can cause gastroenteritis, wound and soft tissue infections, and septicemia (1). Aeromonas spp. may produce an array of virulence factors (e.g., cytolytic toxins with hemolytic activity and enterotoxins). Recent reviews suggested that only a subset of Aeromonas spp. are truly pathogenic and may be transmitted by hitherto unknown routes, and they proposed that further epidemiological and molecular studies are needed (2, 3). Aeromonas species identification has traditionally been performed by a combination of different biochemical tests. However, these are not always conclusive, since some Aeromonas species display heterogeneous biochemical properties; compared to molecular methods, the correct identification rate with biochemical tests has been shown to be very low (4, 5). Molecular species identification has been exploited by the 16S rRNA gene, either by restriction fragment length polymorphism (RFLP) (6-9) or direct sequencing (10, 11). However, due to insufficient interspecies sequence variation and heterogeneity among copies of ribosomal RNA operons in the same bacteria (10, 12, 13), this gene may not be an optimal target. A number of studies have shown that the sequences of several different housekeeping genes are able to differentiate this tight taxonomic group of organisms. These genes include an RNA polymerase B subunit (rpoB), an RNA polymerase D subunit (rpoD), and a DNA gyrase B subunit (gyrB) (10, 14-16). The objective of the present study was to identify species of Aeromonas by partial gyrB and rpoB sequencing in order to develop a multiplex PCR (mPCR) that targets the four most prevalent and clinically relevant species identified by sequence analysis on a Danish strain collection.The strain collection used in this study was composed of 51 Aeromonas spp. collected from diarrheagenic patients during the period of 2005 to 2010. Each stool specimen was grown on enteric medium (Statens Serum Institut, Hillerød, Denmark) (17), and Aeromonas was identified by its distinct colony morphology, while further delineation of clinically relevant species was performed manually according to their biochemical characteristics, including Voges-Proskauer test results and lysine decarboxylase, ornithine decarboxylase, arginine dihydrolase, glucose (gas), esculin, and acid production fr...
Background Increased elastase activity in α1-antitrypsin deficiency may affect elasticity of the arterial walls, and thereby blood pressure and susceptibility to cardiovascular disease. We hypothesized that severe α1-antitrypsin deficiency is associated with reduced blood pressure and susceptibility to cardiovascular disease. Methods We genotyped 91,353 adults randomly selected from the Danish general population and 187 patients from the Danish α1-Antitrypsin Deficiency Registry and recorded baseline blood pressure, baseline plasma lipids and cardiovascular events during follow-up. 185 participants carried the ZZ genotype, 207 carried the SZ genotype and 91,148 carried the MM genotype. Results α1-Antitrypsin deficiency was associated with decreases in blood pressure of up to 5 mmHg for systolic blood pressure and up to 2 mmHg for diastolic blood pressure, in ZZ vs SZ vs MM individuals (trend test, P’s ≤ 0.01). Plasma triglycerides and remnant cholesterol were reduced in ZZ individuals compared with MM individuals (t-test, P’s < 0.001). α1-Antitrypsin deficiency was associated with lower risk of myocardial infarction (trend test P = 0.03), but not with ischemic heart disease, ischemic cerebrovascular disease or hypertension (trend test, P’s ≥ 0.59). However, when results for ischemic heart disease were summarized in meta-analysis with results from four previous studies, individuals with versus without α1-antitrypsin deficiency had an odds ratio for ischemic heart disease of 0.66 (95% CI:0.53–0.84). Conclusions Individuals with severe α1-antitrypsin deficiency have lower systolic and diastolic blood pressure, lower plasma triglycerides and remnant cholesterol, reduced risk of myocardial infarction, and a 34% reduced risk of ischemic heart disease.
BackgroundSP-D is an important host defense lectin in innate immunity and SP-D deficient mice show several abnormal immune effects and are susceptible to allergen-induced airway disease. At the same time, host microbiome interactions play an important role in the development of allergic airway disease, and alterations to gut microbiota have been linked to airway disease through the gut-lung axis. Currently, it is unknown if the genotype (Sftpd-/- or Sftpd+/+) of the standard SP-D mouse model can affect the host microbiota to such an degree that it would overcome the cohousing effect on microbiota and interfere with the interpretation of immunological data from the model. Generally, little is known about the effect of the SP-D protein in itself and in combination with airway disease on the microbiota. In this study, we tested the hypothesis that microbiome composition would change with the lack of SP-D protein and presence of allergic airway disease in the widely used SP-D-deficient mouse model.ResultsWe describe here for the first time the lung and gut microbiota of the SP-D mouse model with OVA induced allergic airway disease. After the challenge animals were killed and fecal samples were taken from the caecum and lungs were subjected to bronchoalveolar lavage for comparison of gut and lung microbiota by Illumina 16S rRNA gene sequencing. A significant community shift was observed in gut microbiota after challenge with OVA. However, the microbial communities were not significantly different between SP-D deficient and wild type mice from the same cages in either naïve or OVA treated animals. Wild type animals did however show the largest variation between mice.ConclusionsOur results show that the composition of the microbiota is not influenced by the SP-D deficient genotype under naïve or OVA induced airway disease. However, OVA sensitization and pulmonary challenge did alter the gut microbiota, supporting a bidirectional lung-gut crosstalk. Future mechanistic investigations of the influence of induced allergic airway disease on gut microbiota are warranted.
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