RESUMEN

Vitamin B12 is an enzymatic cofactor that is essential for both eukaryotes and prokaryotes. The development of life in extreme environments depends on cofactors such as vitamin B12 as well. The genomes of twelve microorganisms isolated from the deep subsurface of the Iberian Pyrite Belt have been analyzed in search of enzymatic activities that require vitamin B12 or are involved in its synthesis and import. Results have revealed that vitamin B12 is needed by these microorganisms for several essential enzymes such as ribonucleotide reductase, methionine synthase and epoxyqueosine reductase. Isolate Desulfosporosinus sp. DEEP is the only analyzed genome that holds a set core of proteins that could lead to the production of vitamin B12. The rest are dependent on obtaining it from the subsurface oligotrophic environment in which they grow. Sought proteins involved in the import of vitamin B12 are not widespread in the sample. The dependence found in the genomes of these microorganisms is supported by the production of vitamin B12 by microorganisms such as Desulfosporosinus sp. DEEP, showing that the operation of deep subsurface biogeochemical cycles is dependent on cofactors such as vitamin B12.

Asunto(s)

RESUMEN

Studies on the role of the oral microbiome in SARS-CoV-2 infection and severity of the disease are limited. We aimed to characterize the bacterial communities present in the saliva of patients with varied COVID-19 severity to learn if there are differences in the characteristics of the microbiome among the clinical groups. We included 31 asymptomatic subjects with no previous COVID-19 infection or vaccination; 176 patients with mild respiratory symptoms, positive or negative for SARS-CoV-2 infection; 57 patients that required hospitalization because of severe COVID-19 with oxygen saturation below 92%, and 18 fatal cases of COVID-19. Saliva samples collected before any treatment were tested for SARS-CoV-2 by PCR. Oral microbiota in saliva was studied by amplification and sequencing of the V1-V3 variable regions of 16S gene using an Illumina MiSeq platform. We found significant changes in diversity, composition, and networking in saliva microbiota of patients with COVID-19, as well as patterns associated with severity of disease. The presence or abundance of several commensal species and opportunistic pathogens were associated with each clinical stage. Patterns of networking were also found associated with severity of disease: a highly regulated bacterial community (normonetting) was found in healthy people whereas poorly regulated populations (disnetting) were characteristic of severe cases. Characterization of microbiota in saliva may offer important clues in the pathogenesis of COVID-19 and may also identify potential markers for prognosis in the severity of the disease. IMPORTANCE SARS-CoV-2 infection is the most severe pandemic of humankind in the last hundred years. The outcome of the infection ranges from asymptomatic or mild to severe and even fatal cases, but reasons for this remain unknown. Microbes normally colonizing the respiratory tract form communities that may mitigate the transmission, symptoms, and severity of viral infections, but very little is known on the role of these microbial communities in the severity of COVID-19. We aimed to characterize the bacterial communities in saliva of patients with different severity of COVID-19 disease, from mild to fatal cases. Our results revealed clear differences in the composition and in the nature of interactions (networking) of the bacterial species present in the different clinical groups and show community-patterns associated with disease severity. Characterization of the microbial communities in saliva may offer important clues to learn ways COVID-19 patients may suffer from different disease severities.

Asunto(s)

RESUMEN

The Iberian Pyrite Belt (IPB) is one of the largest deposits of sulphidic minerals on Earth. Río Tinto raises from its core, presenting low a pH and high metal concentration. Several drilling cores were extracted from the IPB's subsurface, and strain T2.3D-1.1 was isolated from a core at 121.8 m depth. We aimed to characterize this subterranean microorganism, revealing its phylogenomic affiliation (Average Nucleotide Identity, digital DNA-DNA Hybridization) and inferring its physiology through genome annotation, backed with physiological experiments to explore its relationship with the Fe biogeochemical cycle. Results determined that the isolate belongs to the Shewanella putrefaciens (with ANI 99.25 with S. putrefaciens CN-32). Its genome harbours the necessary genes, including omcA mtrCAB, to perform the Extracellular Electron Transfer (EET) and reduce acceptors such as Fe3+, napAB to reduce NO3- to NO2-, hydAB to produce H2 and genes sirA, phsABC and ttrABC to reduce SO32-, S2O32- and S4O62-, respectively. A full CRISPR-Cas 1F type system was found as well. S. putrefaciens T2.3D-1.1 can reduce Fe3+ and promote the oxidation of Fe2+ in the presence of NO3- under anaerobic conditions. Production of H2 has been observed under anaerobic conditions with lactate or pyruvate as the electron donor and fumarate as the electron acceptor. Besides Fe3+ and NO3-, the isolate also grows with Dimethyl Sulfoxide and Trimethyl N-oxide, S4O62- and S2O32- as electron acceptors. It tolerates different concentrations of heavy metals such as 7.5 mM of Pb, 5 mM of Cr and Cu and 1 mM of Cd, Co, Ni and Zn. This array of traits suggests that S. putrefaciens T2.3D-1.1 could have an important role within the Iberian Pyrite Belt subsurface participating in the iron cycle, through the dissolution of iron minerals and therefore contributing to generate the extreme conditions detected in the Río Tinto basin.

RESUMEN

Purpose: Acuity tests for infants and young children use preferential looking methods that require a perceptual match of brightness and color between grey background and target spatial average. As a first step in exploring this matching, this article measures photometric and colorimetric matches in these acuity tests. Methods: The luminance, uniformity, contrast, and color spectra of Teller Acuity Cards, Keeler Acuity Cards for Infants, and Lea Paddles under ambient, warm, and cold lighting, and of grey-emulating patterns on four digital displays, were measured. Five normal adults' acuities were tested at 10 m observationally. Results: Luminance and spectral mismatches between target and background were found for the printed tests (Weber contrasts of 0.3% [Teller Acuity Cards], -1.7% [Keeler Acuity Cards for Infants], and -26% [Lea Paddles]). Lighting condition had little effect on contrast, and all printed tests and digital displays met established adult test luminance and uniformity standards. Digital display grey backgrounds had very similar luminance and color whether generated by a checkerboard, vertical grating, or horizontal grating. Improbably good psychophysical acuities (better than -0.300 logMAR: (logarithm of the minimum angle of resolution)) were recorded from adults using the printed tests at 10 m, but not using the digital test Peekaboo Vision. Conclusions: Perceptible contrast between target and background could lead to an incorrectly measured, excessively good acuity. It is not clear whether the luminance and spectral contrasts described here have clinically meaningful consequences for the target patient group, but they may be avoidable using digital tests. Translational Relevance: Current clinical infant acuity tests present photometric mismatches that may return inaccurate testing results.

Asunto(s)

RESUMEN

Contrast sensitivity is a key visual ability for everyday tasks, as well as a potential indicator of important optical and neurological diseases. Current clinical standards, based on visual discrimination performance on printed charts, present problems that could be bypassed using electronic devices. This work describes the development of new tests for contrast sensitivity, based on the detection of a moving target on a computer screen and in virtual reality headset. It presents preliminary evaluation of these innovations by comparison of their performance, using healthy adults with normal vision and by artificially altering their contrast sensitivity. The results demonstrate consistent correlation between all test modalities explored.

Asunto(s)

RESUMEN

OBJECTIVE: To compare a walking reeducation program with robotic locomotor training plus overground therapy (LKOGT) to conventional overground training (OGT) in individuals with incomplete upper motor neuron (UMN) or lower motor neuron (LMN) injuries having either traumatic or nontraumatic nonprogressive etiology. DESIGN: Randomized open controlled trial with blind evaluation by an independent observer. SETTING: An inpatient spinal cord injury rehabilitation center. PARTICIPANTS: A total of 88 adults within 6 months of spinal cord injury onset (group A, 44 with UMN injury, and group B, 44 with LMN injury) were graded on the American Spinal Injury Association Impairment Scale as C or D. Each of these groups was then randomly allocated to conditions 1 or 2. INTERVENTIONS: Condition 1: Subgroups A1 and B1 were treated with LKOGT for 60 minutes. Condition 2: Subgroups A2 and B2 received 60 minutes of conventional OGT 5 days per week for 8 weeks. Subjects with UMN and LMN were randomized into 2 training groups. MAIN OUTCOME MEASURES: Ten-meter walk test and 6-minute walk test (6MWT). Walking Index for Spinal Cord Injury II, lower extremity motor score (LEMS), and the FIM-Locomotor were secondary outcome measures. RESULTS: By using the LKOGT program compared with OGT, we found significant differences in the 6MWT for groups A1 and B1. LKOGT also provided higher scores than did OGT in secondary outcomes such as the LEMS and the FIM-Locomotor. CONCLUSIONS: Robotic-assisted step training yielded better results in the 6MWT and the LEMS in patients with UMN and LMN.

Asunto(s)

RESUMEN

BACKGROUND: About 75% of persons with ASIA (American Spinal Injury Association) Impairment Scale C and D incomplete spinal cord injury (SCI) achieve walking ability. OBJECTIVE: To compare a walking reeducation program using Lokomat with conventional overground training among individuals with incomplete SCI of both traumatic and nontraumatic etiology. METHODS: A total of 80 participants from 3 to 6 months after onset admitted to 1 site for rehabilitation were included in a single-blind randomized clinical trial of 2 parallel groups, with blind evaluation by independent observers. Patients received 40 walking reeducation sessions of equal time using a Lokomat program with overground practice or overground mobility therapy alone. Primary measurements of outcome were walking speed and the Walking Index for Spinal Cord Injury (WISCI II). Secondary outcomes were the 6-minute walk test, locomotor section of the Functional Independence Measure, Lower Extremity Motor Score (LEMS), Ashworth Scale, and Visual Analog Scale for pain. RESULTS: No significant differences were found at entry between treatment groups. Walking speed for Lokomat (0.4m/s [0.6-0.2]) and overground therapy (0.3m/s [0.5-0.2]) groups did not differ. The WISCI II for the Lokomat group (16 [8.5-19]) was better than for overground therapy (9 [8-16]). The 6-minute walk test and LEMS displayed significant differences in favor of Lokomat therapy but were not corrected for multiple comparisons. CONCLUSIONS: Robotic-assisted training was equivalent to conventional walk training in patients with a variety of nonprogressive spinal cord pathologies for walking speed, but the need for orthotics and assistive devices was reduced, perhaps because of greater leg strength in the robotic group.

Asunto(s)