The Gut as Reservoir of Antibiotic Resistance: Microbial Diversity of Tetracycline Resistance in Mother and Infant

The microbiota in the human gastrointestinal tract (GIT) is highly exposed to antibiotics, and may be an important reservoir of resistant strains and transferable resistance genes. Maternal GIT strains can be transmitted to the offspring, and resistances could be acquired from birth. This is a case study using a metagenomic approach to determine the diversity of microorganisms conferring tetracycline resistance (Tcr) in the guts of a healthy mother-infant pair one month after childbirth, and to investigate the potential for horizontal transfer and maternal transmission of Tcr genes. Fecal fosmid libraries were functionally screened for Tcr, and further PCR-screened for specific Tcr genes. Tcr fosmid inserts were sequenced at both ends to establish bacterial diversity. Mother and infant libraries contained Tcr, although encoded by different genes and organisms. Tcr organisms in the mother consisted mainly of Firmicutes and Bacteroidetes, and the main gene detected was tet(O), although tet(W) and tet(X) were also found. Identical Tcr gene sequences were present in different bacterial families and even phyla, which may indicate horizontal transfer within the maternal GIT. In the infant library, Tcr was present exclusively in streptococci carrying tet(M), tet(L) and erm(T) within a novel composite transposon, Tn6079. This transposon belongs to a family of broad host range conjugative elements, implying a potential for the joint spread of tetracycline and erythromycin resistance within the infant's gut. In addition, although not found in the infant metagenomic library, tet(O) and tet(W) could be detected in the uncloned DNA purified from the infant fecal sample. This is the first study to reveal the diversity of Tcr bacteria in the human gut, to detect a likely transmission of antibiotic resistance from mother to infant GITs and to indicate the possible occurrence of gene transfers among distantly related bacteria coinhabiting the GIT of the same individual

Impact of suppression of the SOS response on protein expression in clinical isolates of Escherichia coli under antimicrobial pressure of ciprofloxacin

Introduction/objective: Suppression of the SOS response in combination with drugs damaging DNA has been proposed as a potential target to tackle antimicrobial resistance. The SOS response is the pathway used to repair bacterial DNA damage induced by antimicrobials such as quinolones. The extent of lexA-regulated protein expression and other associated systems under pressure of agents that damage bacterial DNA in clinical isolates remains unclear. The aim of this study was to assess the impact of this strategy consisting on suppression of the SOS response in combination with quinolones on the proteome profile of Escherichia coli clinical strains. Materials and methods: Five clinical isolates of E. coli carrying different chromosomally- and/or plasmid-mediated quinolone resistance mechanisms with different phenotypes were selected, with E. coli ATCC 25922 as control strain. In addition, from each clinical isolate and control, a second strain was created, in which the SOS response was suppressed by deletion of the recA gene. Bacterial inocula from all 12 strains were then exposed to 1xMIC ciprofloxacin treatment (relative to the wild-type phenotype for each isogenic pair) for 1 h. Cell pellets were collected, and proteins were digested into peptides using trypsin. Protein identification and label-free quantification were done by liquid chromatography-mass spectrometry (LC–MS) in order to identify proteins that were differentially expressed upon deletion of recA in each strain. Data analysis and statistical analysis were performed using the MaxQuant and Perseus software. Results: The proteins with the lowest expression levels were: RecA (as control), AphA, CysP, DinG, DinI, GarL, PriS, PsuG, PsuK, RpsQ, UgpB and YebG; those with the highest expression levels were: Hpf, IbpB, TufB and RpmH. Most of these expression alterations were strain-dependent and involved DNA repair processes and nucleotide, protein and carbohydrate metabolism, and transport. In isolates with suppressed SOS response, the number of underexpressed proteins was higher than overexpressed proteins. Conclusion: High genomic and proteomic variability was observed among clinical isolates and was not associated with a specific resistant phenotype. This study provides an interesting approach to identify new potential targets to combat antimicrobial resistance

A first update on mapping the human genetic architecture of COVID-19

peer reviewe

Genome evolution of a bee-associated bacterium

The use of large-scale comparative genomics allows us to explore the genetic diversity and mechanisms of evolution of related organisms. This thesis has focused on the application of such approaches to study Lactobacillus kunkeei, a bacterial inhabitant of the honeybee gut. We produced 102 novel complete genomes from L. kunkeei, which were used in four large comparative studies. In the first study, 41 bacterial strains were isolated from the crop of honeybees whose populations were geographically isolated. Their genome sequences revealed differences in gene contents, including the mobilome, which were mostly phylogroup-specific. However, differences in strain diversity and co-occurrence between both locations were observed. In the second study, we obtained 61 bacterial isolates from neighboring hives at different timepoints during the summer. We observed that strain diversity seemed hive-specific and relatively constant in time. Surprisingly, the observed mobilome also showed hive specificity and was maintained through the summer. The novel genome data were combined with previously published genomes, allowing us to perform deep comparative analyses on the evolution of the species using a total of 126 genomes. We determined that, despite the large number of sequenced genomes, L. kunkeei has an open pangenome. Besides, we evaluated the effects of recombination on the species core genome, and concluded that it mainly evolves through mutation events. In the last study we described the mechanisms of evolution of a cluster of 5 giant genes (about 90 kb long in total) that are unique to L. kunkeei and the closest sister species. Their patterns of evolution do not reflect those of the species core genome. We concluded that they originated by duplication events, and have diverged by accumulation of both mutations and recombination events. We predicted a potential interaction between the proteins encoded by two of them, and we hypothesized a role in host-specific interaction for another protein. In conclusion, these studies have provided novel and cohesive knowledge on the composition and dynamics of different populations of L. kunkeei, and may have contributed to better understand its ecological niche

Genome evolution of a bee-associated bacterium

The use of large-scale comparative genomics allows us to explore the genetic diversity and mechanisms of evolution of related organisms. This thesis has focused on the application of such approaches to study Lactobacillus kunkeei, a bacterial inhabitant of the honeybee gut. We produced 102 novel complete genomes from L. kunkeei, which were used in four large comparative studies. In the first study, 41 bacterial strains were isolated from the crop of honeybees whose populations were geographically isolated. Their genome sequences revealed differences in gene contents, including the mobilome, which were mostly phylogroup-specific. However, differences in strain diversity and co-occurrence between both locations were observed. In the second study, we obtained 61 bacterial isolates from neighboring hives at different timepoints during the summer. We observed that strain diversity seemed hive-specific and relatively constant in time. Surprisingly, the observed mobilome also showed hive specificity and was maintained through the summer. The novel genome data were combined with previously published genomes, allowing us to perform deep comparative analyses on the evolution of the species using a total of 126 genomes. We determined that, despite the large number of sequenced genomes, L. kunkeei has an open pangenome. Besides, we evaluated the effects of recombination on the species core genome, and concluded that it mainly evolves through mutation events. In the last study we described the mechanisms of evolution of a cluster of 5 giant genes (about 90 kb long in total) that are unique to L. kunkeei and the closest sister species. Their patterns of evolution do not reflect those of the species core genome. We concluded that they originated by duplication events, and have diverged by accumulation of both mutations and recombination events. We predicted a potential interaction between the proteins encoded by two of them, and we hypothesized a role in host-specific interaction for another protein. In conclusion, these studies have provided novel and cohesive knowledge on the composition and dynamics of different populations of L. kunkeei, and may have contributed to better understand its ecological niche

Identification of a Stable Chromosomal Tandem Multicopy of blaVIM-63, a New blaVIM-2 Carbapenemase.

This study characterizes a new genetic structure containing a multicopy of a blaVIM-2 variant with an A676C substitution, blaVIM-63. This gene was detected on the chromosome of two carbapenem-resistant clinical strains of Citrobacter freundii ST22 recovered from two patients, separated by a 6-month period, and previously in Pseudomonas aeruginosa ST2242 from the same hospital unit. Short-read sequencing was used to characterize the new variant in both species, and long-read sequencing was used to characterize the genome of C. freundii. On the P. aeruginosa chromosome, the blaVIM-63 gene was inserted between ISPsy 42-type sequences, flanked by an intl1 sequence, nearby aph(3')-VI, and sul1. On the C. freundii chromosome, the blaVIM-63 gene was inserted into a Tn6230-like transposon as a stable five-tandem-repeat multimer, flanked by the same intl1 as in P. aeruginosa. This structure was stable across subcultures and did not change in the presence of carbapenems. The blaVIM-63 gene was cloned into the pCR-Blunt plasmid to study antimicrobial susceptibility patterns and into pET29a for kinetic activity analysis. VIM-63 showed higher Km values than VIM-2 for ceftazidime and cefepime and higher kcat values for cefotaxime, ceftazidime, imipenem, and ertapenem, without differences in MIC values. This is the first study to describe this new variant, VIM-63, in two different species with a chromosomal location integrated into different mobile elements and the first to describe a stable multimer of a metallo-β-lactamase. Despite the amino acid substitution, the susceptibility pattern of the new variant was similar to that of VIM-2. IMPORTANCE VIM group metallo-β-lactamases are usually captured by IntI1 integrases. This work describes the detection for the first time of a novel, previously unknown variant of VIM-2, VIM-63. This carbapenemase has been found on the chromosome of two different species, Citrobacter freundii and Pseudomonas aeruginosa, from the same hospital. The adjacent genetic environment of the blaVIM-63 gene would indicate that the capture of this gene by IntI1 has occurred in two different genetic events in each of the species, and in one there has been a stable integration of tandem copies of this gene

Onicomi...¿cómo?

Projecte: 2018PID-UB/026El propósito de este material docente es divulgar sobre la importancia del cumplimiento terapéutico en el tratamiento farmacológico tópico de las onicomicosis. Para ello, se recoge información sobre la práctica podológica en el tratamiento farmacológico tópico de las onicomicosis y se investiga qué aspectos serían necesarios resaltar en esta práctica para ofrecer una atención personalizada a los pacientes y optimizar así el cumplimiento terapéutico. Disponer de los mejores medicamentos no asegura el resultado esperado si el paciente se aparta de la prescripción recibida. En una primera etapa, la estudiante de Podología a orientar su plan de acción y recoge información bibliográfica sobre el cumplimiento terapéutico o protocolo de actuación en el tratamiento farmacológico tópico de las onicomicosis. En la segunda etapa, se concreta un producto audiovisual que seduzca a la población diana iniciándose la fase de trabajo interdisciplinar con alumnos del grado de Comunicación Audiovisual. En la etapa final, se elabora el producto audiovisual que muestra los puntos que pueden representar una dificultad para el cumplimiento terapéutico de esta enfermedad: informar del pronóstico y la duración del tratamiento, insistir en la importancia de ser muy constantes en la aplicación del tratamiento, avisar que es largo y requiere dedicación, especificar cómo debe aplicarse el tratamiento, cómo lavar la zona afectada, alertar sobre la no exposición a factores de riesgo e insistir sobre la importancia de finalizar el tratamiento

Ergonómia az építőipar szolgálatában a Tam-Bau Kft.-nél

We conducted a systematic review and individual participant data meta-analysis to explore the role of C-reactive protein (CRP) in early detection or prediction of post-stroke infections. CRP, an acute-phase reactant binds to the phosphocholine expressed on the surface of dead or dying cells and some bacteria, thereby activating complement and promoting phagocytosis by macrophages. We searched PubMed up to May-2015 for studies measuring CRP in stroke and evaluating post-stroke infections. Individual participants' data were merged into a single database. CRP levels were standardized and divided into quartiles. Factors independently associated with post-stroke infections were determined by logistic regression analysis and the additional predictive value of CRP was assessed by comparing areas under receiver operating characteristic curves and integrated discrimination improvement index. Data from seven studies including 699 patients were obtained. Standardized CRP levels were higher in patients with post-stroke infections beyond 24 h. Standardized CRP levels in the fourth quartile were independently associated with infection in two different logistic regression models, model 1 [stroke severity and dysphagia, odds ratio = 9.70 (3.10-30.41)] and model 2 [age, sex, and stroke severity, odds ratio = 3.21 (1.93-5.32)]. Addition of CRP improved discrimination in both models [integrated discrimination improvement = 9.83% (0.89-18.77) and 5.31% (2.83-7.79), respectively], but accuracy was only improved for model 1 (area under the curve 0.806-0.874, p = 0.036). In this study, CRP was independently associated with development of post-stroke infections, with the optimal time-window for measurement at 24-48 h. However, its additional predictive value is moderate over clinical information. Combination with other biomarkers in a panel seems a promising strategy for future studies

Our Common Past, Our Future. III ESACH Meeting, Madrid 7th-9th June 2021. Book of Proceedings

The III ESACH 2021 Madrid Meeting, "Our Common Past, Our Future", was organised by the European Students' Association for Cultural Heritage (ESACH), and the MA Cultural Heritage in the 21st Century: Management and Research (a joint postgraduate degree of the Universidad Complutense de Madrid and the Universidad Politécnica de Madrid). This conference has been a meeting to exchange knowledge and ideas about our European heritage, but also to think about sustainable ways to manage it - because we are the future of Europe and that must be our commitment

Safety and Outcome of Revascularization Treatment in Patients With Acute Ischemic Stroke and COVID-19: The Global COVID-19 Stroke Registry.

BACKGROUND AND OBJECTIVES COVID-19 related inflammation, endothelial dysfunction and coagulopathy may increase the bleeding risk and lower efficacy of revascularization treatments in patients with acute ischemic stroke. We aimed to evaluate the safety and outcomes of revascularization treatments in patients with acute ischemic stroke and COVID-19. METHODS Retrospective multicenter cohort study of consecutive patients with acute ischemic stroke receiving intravenous thrombolysis (IVT) and/or endovascular treatment (EVT) between March 2020 and June 2021, tested for SARS-CoV-2 infection. With a doubly-robust model combining propensity score weighting and multivariate regression, we studied the association of COVID-19 with intracranial bleeding complications and clinical outcomes. Subgroup analyses were performed according to treatment groups (IVT-only and EVT). RESULTS Of a total of 15128 included patients from 105 centers, 853 (5.6%) were diagnosed with COVID-19. 5848 (38.7%) patients received IVT-only, and 9280 (61.3%) EVT (with or without IVT). Patients with COVID-19 had a higher rate of symptomatic intracerebral hemorrhage (SICH) (adjusted odds ratio [OR] 1.53; 95% CI 1.16-2.01), symptomatic subarachnoid hemorrhage (SSAH) (OR 1.80; 95% CI 1.20-2.69), SICH and/or SSAH combined (OR 1.56; 95% CI 1.23-1.99), 24-hour (OR 2.47; 95% CI 1.58-3.86) and 3-month mortality (OR 1.88; 95% CI 1.52-2.33).COVID-19 patients also had an unfavorable shift in the distribution of the modified Rankin score at 3 months (OR 1.42; 95% CI 1.26-1.60). DISCUSSION Patients with acute ischemic stroke and COVID-19 showed higher rates of intracranial bleeding complications and worse clinical outcomes after revascularization treatments than contemporaneous non-COVID-19 treated patients. Current available data does not allow direct conclusions to be drawn on the effectiveness of revascularization treatments in COVID-19 patients, or to establish different treatment recommendations in this subgroup of patients with ischemic stroke. Our findings can be taken into consideration for treatment decisions, patient monitoring and establishing prognosis