Pulmonary aspergillosis is a severe infectious disease caused by some members of the
genus, that affects immunocompetent as well as immunocompromised patients. Among the different disease forms, ...Invasive Aspergillosis is the one causing the highest mortality, mainly, although not exclusively, affecting neutropenic patients. This genus is very well known by humans, since different sectors like pharmaceutical or food industry have taken advantage of the biological activity of some molecules synthetized by the fungus, known as secondary metabolites, including statins, antibiotics, fermentative compounds or colorants among others. However, during infection, in response to a hostile host environment, the fungal secondary metabolism is activated, producing different virulence factors to increase its survival chances. Some of these factors also contribute to fungal dissemination and invasion of adjacent and distant organs. Among the different secondary metabolites produced by
spp. Gliotoxin (GT) is the best known and better characterized virulence factor. It is able to generate reactive oxygen species (ROS) due to the disulfide bridge present in its structure. It also presents immunosuppressive activity related with its ability to kill mammalian cells and/or inactivate critical immune signaling pathways like NFkB. In this comprehensive review, we will briefly give an overview of the lung immune response against
as a preface to analyse the effect of different secondary metabolites on the host immune response, with a special attention to GT. We will discuss the results reported in the literature on the context of the animal models employed to analyse the role of GT as virulence factor, which is expected to greatly depend on the immune status of the host: why should you hide when nobody is seeking for you? Finally, GT immunosuppressive activity will be related with different human diseases predisposing to invasive aspergillosis in order to have a global view on the potential of GT to be used as a target to treat IA.
Ibrexafungerp (SCY-078) is the newest oral and intravenous antifungal drug with broad activity, currently undergoing clinical trials for invasive candidiasis.
The aim of this study was to assess the
...activity of ibrexafungerp and comparators against a collection of 434 European blood isolates of
.
Ibrexafungerp, caspofungin, fluconazole, and micafungin minimum inhibitory concentrations (MICs) were collected from 12 European laboratories for 434 blood isolates, including 163
, 108
, 60
, 40
, 29
, 20
, 6
, 2
, 2
, and 1 isolate each of
,
, and
. MICs were determined by the EUCAST broth microdilution method, and isolates were classified according to recommended clinical breakpoints and epidemiological cutoffs. Additionally, 22
from different clinical specimens were evaluated.
Ibrexafungerp MICs ranged from 0.016 to ≥8 mg/L. The lowest ibrexafungerp MICs were observed for
(geometric MIC 0.062 mg/L, MIC range 0.016-0.5 mg/L) and the highest ibrexafungerp MICs were observed for
(geometric MIC 0.517 mg/L, MIC range 0.06-≥8 mg/L). Modal MICs/MIC
s (mg/L) against
spp. were 0.125/0.06 for
, 0.5/0.5 for
, 0.25/0.25 for
, 0.5/0.5 for
, 1/1 for
, 4/2 for
, and 0.5/0.5 for
. Ibrexafungerp showed activity against fluconazole- and echinocandin-resistant isolates. If adopting wild-type upper limits, a non-wild-type phenotype for ibrexafungerp was only observed for 16/434 (3.7%) isolates: 11 (4.6%)
, 4 (5%)
, and 1 (2.5%)
.
Ibrexafungerp showed a potent
activity against
.
This study aimed to assess the ultra-fast method using MinION™ sequencing for rapid identification of β-lactamase-producing
clinical isolates from positive blood cultures.
Spiked-blood positive blood ...cultures were extracted using the ultra-fast method and automated DNA extraction for MinION sequencing. Raw reads were analyzed for β-lactamase resistance genes. Multilocus sequence typing and β-lactamase variant characterization were performed after assembly.
The ultra-fast method identified clinically relevant β-lactamase resistance genes in less than 1 h. Multilocus sequence typing and β-lactamase variant characterization required 3-6 h. Sequencing quality showed no direct correlation with pore number or DNA concentration.
Nanopore sequencing, specifically the ultra-fast method, is promising for the rapid diagnosis of bloodstream infections, facilitating timely identification of multidrug-resistant bacteria in clinical samples.
Gliotoxin (GT) is a fungal secondary metabolite that has attracted great interest due to its high biological activity since it was discovered by the 1930s. An inactive derivative of this molecule, ...bis(methylthio)gliotoxin (bmGT), has been proposed as an invasive aspergillosis (IA) biomarker. Nevertheless, studies regarding bmGT production among common opportunistic fungi, including the
genus, are scarce and sometimes discordant. As previously reported, bmGT is produced from GT by a methyl-transferase, named as GtmA, as a negative feedback regulatory system of GT production. In order to analyze the potential of bmGT detection to enable identification of infections caused by different members of the
genus we have assessed bmGT production within the genus
, including
,
,
, and
, and its correlation with
presence. In order to validate the relevance of our
findings, we compared bmGT during
culture with the presence of bmGT in sera of patients from whom the
spp. were isolated. Our results indicate that most
isolates produce GT and bmGT both
and
. In contrast,
and
were not able to produce GT or bmGT, although
produced bmGT from a exogenous GT source. The frequency and amount of bmGT production in
and
isolates
was lower than in
. Our results suggest that this defect could be related to the
culture conditions, since isolates that did not produce bmGT
were able to synthetize it
. In summary, our study indicates that bmGT could be very useful to specifically detect the presence of
, the most prevalent agent causing IA. Concerning
and
a higher number of analyses from sera from infected patients will be required to reach a useful conclusion.
Several amino acid changes have been previously implicated in adaptation of avian influenza viruses to human hosts, among them the D701N change in the PB2 polymerase subunit that also is the main ...determinant of avian virus pathogenesis in animal models. However, previous studies using recombinant viruses did not provide conclusive information of the contribution of this PB2 residue to pathogenicity in human influenza virus strains. We identified this mutation in an A(H1N1)pdm09-like human influenza virus isolated from an infected patient with pneumonia and acute respiratory failure, admitted to the intensive care unit. An exhaustive search has revealed PB2-D701 as a highly conserved position in all available H1N1 human virus sequences in NCBI database, showing a very low prevalence of PB2-D701N change. Presence of PB2-701N amino acid correlates with severe or fatal outcome in those scarce cases with known disease outcome of the infection. In these patients, the residue PB2-701N may contribute to pathogenicity as it was previously reported in humans infected with avian viruses. This study helps to clarify a debate that has arisen regarding the role of PB2-D701N in human influenza virus pathogenicity.
Summary
In general, it is recommended to incubate dermatophytes cultures for a minimum of 4 weeks. Several aspects of routine fungal cultures should be evaluated in order to implement appropriate and ...necessary changes. The aim of this study was to determine the optimum incubation time for routine dermatophytes cultures, analysing the time to find first fungal growth by visual observation. We recorded the time when the initial growth was detected for all dermatophyte isolates during a 4‐year period. A total of 5459 dermatophyte cultures were submitted to our laboratory. From the total cultures, only 16 (1.42%) isolates were recovered over/after 17 days of incubation and only three dermatophyte species were recovered over 17 days. Fourteen isolates belong to Trichophyton rubrum, one isolate to Trichophyton mentagrophytes complex and one isolate to Epidermophyton floccosum. We concluded that an incubation period of 17 days is enough to establish a microbiological diagnosis of dermatophytosis.
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BFBNIB, DOBA, FZAB, GIS, IJS, IZUM, KILJ, NLZOH, NUK, OILJ, PILJ, PNG, SAZU, SBCE, SBMB, UILJ, UKNU, UL, UM, UPUK
Early and accurate diagnosis of invasive aspergillosis (IA) is one of the most critical steps needed to efficiently treat the infection and reduce the high mortality rates that can occur. We have ...previously found that the Aspergillus spp. secondary metabolite, bis(methylthio)gliotoxin (bmGT), can be detected in the serum from patients with possible/probable IA. Thus, it could be used as a diagnosis marker of the infection. However, there is no data available concerning the sensitivity, specificity and performance of bmGT to detect the infection. Here, we have performed a prospective study comparing bmGT detection with galactomannan (GM), the most frequently used and adopted approach for IA diagnosis, in 357 sera from 90 episodes of patients at risk of IA. Our results, involving 79 patients that finally met inclusion criteria, suggest that bmGT presents higher sensitivity and positive predictive value (PPV) than GM and similar specificity and negative predictive value (NPV). Importantly, the combination of GM and bmGT increased the PPV (100 %) and NPV (97.5 %) of the individual biomarkers, demonstrating its potential utility in empirical antifungal treatment guidance and withdrawal. These results indicate that bmGT could be a good biomarker candidate for IA diagnosis and, in combination with GM, could result in highly specific diagnosis of IA and management of patients at risk of infection.
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CEKLJ, DOBA, EMUNI, FZAB, GEOZS, IJS, IMTLJ, IZUM, KILJ, KISLJ, MFDPS, NUK, OILJ, PILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UILJ, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
Abstract Background Disseminated invasive aspergillosis is an exceptional finding in immunocompetent hosts. As in immunocompromised patients, it has high mortality rates. Early diagnostic methods are ...required in order to properly manage the patient. Bis(methylthio)gliotoxin (bmGT) is a novel biomarker, useful in onco-hematological patients. Case report A 70-year-old male, with non-insulin dependent type II diabetes mellitus and a past surgery history of aortic valve replacement with coronary by-pass five years ago, was seen in the emergency department with blurred vision. Three days later, endogen endophthalmitis was diagnosed in the ophthalmology clinic. During admission for the vitrectomy, he suffered an ischemia of the right lower limb. A thoracic computed tomography revealed a mycotic aneurysm of the ascending thoracic aorta and parietal thrombus. The ascending aorta was replaced and abundant brittle material of infectious appearance, found between the aortic valve graft and the aneurysm, was removed. Aspergillus fumigatus sensu stricto grew in both vitreous and aorta cultures. BmGT was detected in two serum samples obtained prior to intravenous antifungal treatment, which was then reduced after voriconazole treatment was started. Conclusions Disseminated invasive aspergillosis is a severe disease regardless of the immune status of the patient. This case report suggests that bmGT could be a suitable early diagnostic biomarker, not only in neutropenic patients, but also in immunocompetent hosts.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK, ZRSKP
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