Background
The relationship of host immune response and viral replication with health outcomes in patients with COVID-19 remains to be defined. We aimed to characterize the medium and long-term ...clinical, virological, and serological outcomes after hospitalization for COVID-19, and to identify predictors of long-COVID.
Methods
Prospective, longitudinal study conducted in COVID-19 patients confirmed by RT-PCR. Serial blood and nasopharyngeal samples (NPS) were obtained for measuring SARS-CoV-2 RNA and S-IgG/N-IgG antibodies during hospital stay, and at 1, 2, and 6 months post-discharge. Genome sequencing was performed where appropriate. Patients filled out a COVID-19 symptom questionnaire (CSQ) at 2-month and 6-month visits, and those with highest scores were characterized.
Results
Of 146 patients (60% male, median age 64 years) followed-up, 20.6% required hospital readmission and 5.5% died. At 2 months and 6 months, 9.6% and 7.8% patients, respectively, reported moderate/severe persistent symptoms. SARS-CoV-2 RT-PCR was positive in NPS in 11.8% (median Ct = 38) and 3% (median Ct = 36) patients at 2 months and 6 months, respectively, but no reinfections were demonstrated. Antibody titers gradually waned, with seroreversion occurring at 6 months in 27 (27.6%) patients for N-IgG and in 6 (6%) for S-IgG. Adjusted 2-month predictors of the highest CSQ scores (OR 95%CI) were lower peak S-IgG (0.80 0.66–0.94) and higher WHO severity score (2.57 1.20–5.86); 6-month predictors were lower peak S-IgG (0.89 0.79–0.99) and female sex (2.41 1.20–4.82); no association was found with prolonged viral RNA shedding.
Conclusions
Long-COVID is associated with weak anti-SARS-CoV-2 antibody response, severity of illness, and female gender. Late clinical events and persistent symptoms in the medium and long term occur in a significant proportion of patients hospitalized for COVID-19.
The pUM505 plasmid, isolated from a clinical
isolate, confers resistance to ciprofloxacin (CIP) when transferred into the standard
strain PAO1. CIP is an antibiotic of the quinolone family that is ...used to treat
infections.
analysis, performed to identify CIP resistance genes, revealed that the 65-amino-acid product encoded by the
gene in pUM505 displays 40% amino acid identity to the
aminoglycoside phosphotransferase (an enzyme that phosphorylates and inactivates aminoglycoside antibiotics). We cloned
(renamed
, for
iprofloxacin
esistance
rotein,
lasmid encoded) into the pUCP20 shuttle vector. The resulting recombinant plasmid, pUC-
, conferred resistance to CIP on
strain J53-3, suggesting that this gene encodes a protein involved in CIP resistance. Using coupled enzymatic analysis, we determined that the activity of CrpP on CIP is ATP dependent, while little activity against norfloxacin was detected, suggesting that CIP may undergo phosphorylation. Using a recombinant His-tagged CrpP protein and liquid chromatography-tandem mass spectrometry, we also showed that CIP was phosphorylated prior to its degradation. Thus, our findings demonstrate that CrpP, encoded on the pUM505 plasmid, represents a new mechanism of CIP resistance in
, which involves phosphorylation of the antibiotic.
Mucor circinelloides
is a dimorphic Zygomycete fungus that produces ethanol under aerobic conditions in the presence of glucose, which indicates that it is a Crabtree-positive fungus. To determine ...the physiological role of the alcohol dehydrogenase (ADH) activity elicited under these conditions, we obtained and characterized an allyl alcohol-resistant mutant that was defective in ADH activity, and examined the effect of
adh
mutation on physiological parameters related to carbon and energy metabolism. Compared to the Adh
+
strain R7B, the ADH-defective (Adh
-
) strain M5 was unable to grow under anaerobic conditions, exhibited a considerable reduction in ethanol production in aerobic cultures when incubated with glucose, had markedly reduced growth capacity in the presence of oxygen when ethanol was the sole carbon source, and exhibited very low levels of NAD
+
-dependent alcohol de-hydrogenase activity in the cytosolic fraction. Further characterization of the M5 strain showed that it contains a 10-bp deletion that interrupts the coding region of the
adhl
gene. Complementation with the wild-type allele
adh1
+
by transformation of M5 remedied all the defects caused by the
adh1
mutation. These findings indicate that in
M. circinelloides
, the product of the
adh1
gene mediates the Crabtree effect, and can act as either a fermentative or an oxidative enzyme, depending on the nutritional conditions, thereby participating in the association between fermentative and oxidative metabolism. It was found that the spores of
M. circinelloides
possess low mRNA levels of the ethanol assimilation genes (
adl2
and
acs2
), which could explain their inability to grow in the alcohol.
Fungal alcohol dehydrogenases (ADHs) participate in growth under aerobic or anaerobic conditions, morphogenetic processes, and pathogenesis of diverse fungal genera. These processes are associated ...with metabolic operation routes related to alcohol, aldehyde, and acid production. The number of ADH enzymes, their metabolic roles, and their functions vary within fungal species. The most studied ADHs are associated with ethanol metabolism, either as fermentative enzymes involved in the production of this alcohol or as oxidative enzymes necessary for the use of ethanol as a carbon source; other enzymes participate in survival under microaerobic conditions. The fast generation of data using genome sequencing provides an excellent opportunity to determine a correlation between the number of ADHs and fungal lifestyle. Therefore, this review aims to summarize the latest knowledge about the importance of ADH enzymes in the physiology and metabolism of fungal cells, as well as their structure, regulation, evolutionary relationships, and biotechnological potential.
Introduction:
Chronic obstructive sialadenitis (COS) is an entity that causes a marked loss in patient quality of life, including changes in eating habits and a progressive loss of gland function. It ...is characterized by repeated episodes of painful glandular swelling often requiring emergency care. There are multiple causes of COS, including lithiasis, strictures, anatomical variants, and others. The development of specific imaging tests such as magnetic resonance (MR) sialography or sialendoscopy have increased knowledge of these obstructions and how to specifically treat them.
Case Summary:
We present an unusual case of a woman with a years-long history of chronic obstructive sialadenitis in which an abnormal path of Wharton’s duct was in evidence. This duct, which was atrophic and smaller in diameter, opened in the tonsillar fossa rather than lateral to the lingual frenulum. This case, the first in vivo description of its kind, was confirmed by MR sialography and sialendoscopy.
Discussion:
Congenital anomalies of the submandibular duct are a rare finding, but may cause COS. Therefore, COS requires a detailed diagnostic study, usually by ultrasound, MR sialography and sialendoscopy, to rule out complex anatomical variants.
We investigated the association of genetic polymorphisms in chemokine and chemokine receptor genes with poor immunological recovery in HIV patients starting combined antiretroviral therapy (cART) ...with low CD4 T-cell counts.
A case-control study was conducted in 412 HIV-infected patients starting cART with CD4 T-cell count <200 cells/μL and successful viral control for two years. CD4 count increase below 200 cells/μL after two years on cART was used to define INR (immunological non-responder) patients. Polymorphisms in CXCL12, CCL5 and CCR2 genes were genotyped using sequenom's MassARRAY platform.
Thirty two percent (134/412) of patients were classified as INR. After adjusting by age, route of HIV infection, length of infection before cART and viral hepatitis coinfection, CCR2 rs1799864-AG genotype was significantly associated with INR status (OR 95% CI: 1.80 1.04-3.11; p = 0.04), and CXCL12 rs1801157-TT genotype showed a trend (OR 95% CI: 2.47 0.96-6.35; p = 0.06).
CCR2 rs1799864-AG or CXCL12 rs1801157-TT genotypes influence on the probability of poor CD4 recovery in the population of HIV patients starting cART with low CD4 counts. Genotyping of these polymorphisms could be used to estimate the risk of poor CD4 restoration, mainly in patients who are diagnosed late in the course of infection.
Chromium pollution is potentially detrimental to bacterial soil communities, compromising carbon and nitrogen cycles that are essential for life on earth. It has been proposed that intracellular ...reduction of hexavalent chromium Cr(VI) to trivalent chromium Cr(III) may cause bacterial death by a mechanism that involves reactive oxygen species (ROS)-induced DNA damage; the molecular basis of the phenomenon was investigated in this work. Here, we report that Bacillus subtilis cells lacking a functional error prevention oxidized guanine (GO) system were significantly more sensitive to Cr(VI) treatment than cells of the wild-type (WT) strain, suggesting that oxidative damage to DNA is involved in the deleterious effects of the oxyanion. In agreement with this suggestion, Cr(VI) dramatically increased the ROS concentration and induced mutagenesis in a GO-deficient B. subtilis strain. Alkaline gel electrophoresis (AGE) analysis of chromosomal DNA of WT and ΔGO mutant strains subjected to Cr(VI) treatment revealed that the DNA of the ΔGO strain was more susceptible to DNA glycosylase Fpg attack, suggesting that chromium genotoxicity is associated with 7,8-dihydro-8-oxodeoxyguanosine (8-oxo-G) lesions. In support of this notion, specific monoclonal antibodies detected the accumulation of 8-oxo-G lesions in the chromosomes of B. subtilis cells subjected to Cr(VI) treatment. We conclude that Cr(VI) promotes mutagenesis and cell death in B. subtilis by a mechanism that involves radical oxygen attack of DNA, generating 8-oxo-G, and that such effects are counteracted by the prevention and repair GO system.
The fungus
undergoes yeast-mold dimorphism, a developmental process associated with its capability as a human opportunistic pathogen. Dimorphism is strongly influenced by carbon metabolism, and hence ...the type of metabolism likely affects fungus virulence. We investigated the role of ethanol metabolism in
virulence. A mutant in the
gene (M5 strain) exhibited higher virulence than the wild-type (R7B) and the complemented (M5/pEUKA-
) strains, which were nonvirulent when tested in a mouse infection model. Cell-free culture supernatant (SS) from the M5 mutant showed increased toxic effect on nematodes compared to that from R7B and M5/pEUKA-
strains. The concentration of acetaldehyde excreted by strain M5 in the SS was higher than that from R7B, which correlated with the acute toxic effect on nematodes. Remarkably, strain M5 showed higher resistance to H
O
, resistance to phagocytosis, and invasiveness in mouse tissues and induced an enhanced systemic inflammatory response compared with R7B. The mice infected with strain M5 under disulfiram treatment exhibited only half the life expectancy of those infected with M5 alone, suggesting that acetaldehyde produced by
contributes to the toxic effect in mice. These results demonstrate that the failure in fermentative metabolism, in the step of the production of ethanol in
, contributes to its virulence, inducing a more severe tissue burden and inflammatory response in mice as a consequence of acetaldehyde overproduction.
Anthropogenic extreme environments are among the most interesting sites for the bioprospection of extremophiles since the selection pressures may favor the presence of microorganisms of great ...interest for taxonomical and astrobiological research as well as for bioremediation technologies and industrial applications. In this work, T-RFLP and 16S rRNA gene library analyses were carried out to describe the autochthonous bacterial populations from an industrial waste characterized as hyper-alkaline (pH between 9 and 14), hyper-saline (around 100 PSU) and highly contaminated with metals, mainly chromium (from 5 to 18 g kg
−1
) and iron (from 2 to 108 g kg
−1
). Due to matrix interference with DNA extraction, a protocol optimization step was required in order to carry out molecular analyses. The most abundant populations, as evaluated by both T-RFLP and 16S rRNA gene library analyses, were affiliated to
Bacillus
and
Lysobacter
genera.
Lysobacter
related sequences were present in the three samples: solid residue and lixiviate sediments from both dry and wet seasons. Sequences related to
Thiobacillus
were also found; although strains affiliated to this genus are known to have tolerance to metals, they have not previously been detected in alkaline environments. Together with
Bacillus
(already described as a metal reducer), such organisms could be of use in bioremediation technologies for reducing chromium, as well as for the prospection of enzymes of biotechnological interest.
The presence of pollutants in soil and water has given rise to diverse analytical and biological approaches to detect and measure contaminants in the environment. Using bacterial cells as reporter ...strains represents an advantage for detecting pollutants present in soil or water samples. Here, an
Escherichia coli
reporter strain expressing a chromoprotein capable of interacting with soil or water samples and responding to DNA damaging compounds is validated. The reporter strain generates a qualitative signal and is based on the expression of the coral chromoprotein AmilCP under the control of the
recA
promoter. This strain can be used simply by applying soil or water samples directly and rendering activation upon DNA damage. This reporter strain responds to agents that damage DNA (with an apparent detection limit of 1 µg of mitomycin C) without observable response to membrane integrity damage, protein folding or oxidative stress generating agents, in the latter case, DNA damage was observed. The developed reporter strain reported here is effective for the detection of DNA damaging agents present in soils samples. In a proof-of-concept analysis using soil containing chromium, showing activation at 15.56 mg/L of Cr(VI) present in soil and leached samples and is consistent with Cr(III) toxicity at high concentrations (130 µg). Our findings suggest that chromogenic reporter strains can be applied for simple screening, thus reducing the number of samples requiring analytical techniques.
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