Serotype distribution, clinical characteristics, and antimicrobial resistance of pediatric invasive pneumococcal disease in Colombia during PCV10 mass vaccination (2017-2022).

Introduction: Invasive Pneumococcal Disease (IPD) causes significant morbidity and mortality in children under 5 y. Colombia introduced PCV10 vaccination in 2012, and the Neumocolombia network has been monitoring IPD in pediatric patients since 2008. Materials and methods: This study is a secondary analysis of a prospective cohort involving pediatric patients with IPD admitted to 17 hospitals in Colombia, from January 1st, 2017, to December 31st, 2022. We present data on serotypes (Spn), clinical characteristics, and resistance patterns. Results: We report 530 patients, 215 (40.5%) were younger than 24 months. Among these, 344 cases (64.7%) presented with pneumonia, 95 (17.9%) with primary bacteremia, 53 (10%) with meningitis, 6 (1.1%) had pneumonia and meningitis, and 32 (6%) had other IPD diagnosis. The median hospital stay was 12 days (RIQ 8-14 days), and 268 (50.6%) were admitted to the ICU, of whom 60 (11.3%) died. Serotyping was performed in 298 (56.1%). The most frequent serotypes were Spn19A (51.3%), Spn6C (7.7%), Spn3 (6.7%), Spn6A (3.6%), and Spn14 (3.6%). Of 495 (93%) isolates with known susceptibility, 46 (9.2%) were meningeal (M) and 449 (90.7%) non-meningeal (NM). Among M isolates, 41.3% showed resistance to penicillin, and 21.7% decreased susceptibility to ceftriaxone. For NM isolates, 28.2% had decreased susceptibility to penicilin, and 24.2% decreased susceptibility to ceftriaxone. Spn19A showed the highest resistant to penicillin at 47% and was linked to multiresistance. Conclusion: The prevalence of PCV10-included serotypes decreased, while serotypes 19A and 6C increased, with Spn19A being associated with multiresistance. These findings had played a crucial role in the decision made by Colombia to modify its immunization schedule by switching to PCV13 in July 2022.

Cryptic environmental conjugative plasmid recruits a novel hybrid transposon resulting in a new plasmid with higher dispersion potential.

Cryptic conjugative plasmids lack antibiotic-resistance genes (ARGs). These plasmids can capture ARGs from the vast pool of the environmental metagenome, but the mechanism to recruit ARGs remains to be elucidated. To investigate the recruitment of ARGs by a cryptic plasmid, we sequenced and conducted mating experiments with Escherichia coli SW4848 (collected from a lake) that has a cryptic IncX (IncX4) plasmid and an IncF (IncFII/IncFIIB) plasmid with five genes that confer resistance to aminoglycosides (strA and strB), sulfonamides (sul2), tetracycline [tet(A)], and trimethoprim (dfrA5). In a conjugation experiment, a novel hybrid Tn21/Tn1721 transposon of 22,570 bp (designated Tn7714) carrying the five ARG mobilized spontaneously from the IncF plasmid to the cryptic IncX plasmid. The IncF plasmid was found to be conjugative when it was electroporated into E. coli DH10B (without the IncX plasmid). Two parallel conjugations with the IncF and the new IncX (carrying the novel Tn7714 transposon) plasmids in two separate E. coli DH10B as donors and E. coli J53 as the recipient revealed that the conjugation rate of the new IncX plasmid (with the novel Tn7714 transposon and five ARGs) is more than two orders of magnitude larger than the IncF plasmid. For the first time, this study shows experimental evidence that cryptic environmental plasmids can capture and transfer transposons with ARGs to other bacteria, creating novel multidrug-resistant conjugative plasmids with higher dispersion potential. IMPORTANCE: Cryptic conjugative plasmids are extrachromosomal DNA molecules without antibiotic-resistance genes (ARGs). Environmental bacteria carrying cryptic plasmids with a high conjugation rate threaten public health because they can capture clinically relevant ARGs and rapidly spread them to pathogenic bacteria. However, the mechanism to recruit ARG by cryptic conjugative plasmids in environmental bacteria has not been observed experimentally. Here, we document the first translocation of a transposon with multiple clinically relevant ARGs to a cryptic environmental conjugative plasmid. The new multidrug-resistant conjugative plasmid has a conjugation rate that is two orders of magnitude higher than the original plasmid that carries the ARG (i.e., the new plasmid from the environment can spread ARG more than two orders of magnitude faster). Our work illustrates the importance of studying the mobilization of ARGs in environmental bacteria. It sheds light on how cryptic conjugative plasmids recruit ARGs, a phenomenon at the root of the antibiotic crisis.

Risk Factors Associated with Intensive Care Admission in Children with Severe Acute Respiratory Syndrome Coronavirus 2-Related Multisystem Inflammatory Syndrome (MIS-C) in Latin America: A Multicenter Observational Study of the REKAMLATINA Network.

Background: Multisystem inflammatory syndrome in children (MIS-C) associated with coronavirus disease 2019 varies widely in its presentation and severity, with low mortality in high-income countries. In this study in 16 Latin American countries, we sought to characterize patients with MIS-C in the pediatric intensive care unit (PICU) compared with those hospitalized on the general wards and analyze the factors associated with severity, outcomes, and treatment received. Study Design: An observational ambispective cohort study was conducted including children 1 month to 18 years old in 84 hospitals from the REKAMLATINA network from January 2020 to June 2022. Results: A total of 1239 children with MIS-C were included. The median age was 6.5 years (IQR 2.5-10.1). Eighty-four percent (1043/1239) were previously healthy. Forty-eight percent (590/1239) were admitted to the PICU. These patients had more myocardial dysfunction (20% vs 4%; P < 0.01) with no difference in the frequency of coronary abnormalities (P = 0.77) when compared to general ward subjects. Of the children in the PICU, 83.4% (494/589) required vasoactive drugs, and 43.4% (256/589) invasive mechanical ventilation, due to respiratory failure and pneumonia (57% vs 32%; P = 0.01). On multivariate analysis, the factors associated with the need for PICU transfer were age over 6 years (aOR 1.76 95% CI 1.25-2.49), shock (aOR 7.06 95% CI 5.14-9.80), seizures (aOR 2.44 95% CI 1.14-5.36), thrombocytopenia (aOR 2.43 95% CI 1.77-3.34), elevated C-reactive protein (aOR 1.89 95% CI 1.29-2.79), and chest x-ray abnormalities (aOR 2.29 95% CI 1.67-3.13). The overall mortality was 4.8%. Conclusions: Children with MIS-C who have the highest risk of being admitted to a PICU in Latin American countries are those over age six, with shock, seizures, a more robust inflammatory response, and chest x-ray abnormalities. The mortality rate is five times greater when compared with high-income countries, despite a high proportion of patients receiving adequate treatment.

Detection of Horizontal Gene Transfer Mediated by Natural Conjugative Plasmids in E. coli.

Conjugation represents one of the main mechanisms facilitating horizontal gene transfer in Gram-negative bacteria. This work describes methods for the study of the mobilization of naturally occurring conjugative plasmids, using two naturally-occurring plasmids as an example. These protocols rely on the differential presence of selectable markers in donor, recipient, and conjugative plasmid. Specifically, the methods described include 1) the identification of natural conjugative plasmids, 2) the quantification of conjugation rates in solid culture, and 3) the diagnostic detection of the antibiotic resistance genes and plasmid replicon types in transconjugant recipients by polymerase chain reaction (PCR). The protocols described here have been developed in the context of studying the evolutionary ecology of horizontal gene transfer, to screen for the presence of conjugative plasmids carrying antibiotic-resistance genes in bacteria found in the environment. The efficient transfer of conjugative plasmids observed in these experiments in culture highlights the biological relevance of conjugation as a mechanism promoting horizontal gene transfer in general and the spread of antibiotic resistance in particular.

The PRINCIPAL Network: A Model to Optimize Infection Care and Prevention in Pediatric Oncology in the Latin American Region.

PURPOSE: Children with cancer are at high risk for poor outcomes, and health care providers are often unfamiliar with best practices in infection care and prevention (IC&P) in this small and fragile population. Graduates of training courses in IC&P in immunocompromised hosts identified a need for a community that would enable members to share health care experiences, provide resources for continuing medical education, and foster collaborative research and quality improvement opportunities. We developed a Latin American network, Prevencionistas e Infectólogos para Cáncer Pediátrico en América Latina, to grow and sustain the expertise of the clinical workforce in IC&P. Here, we describe the network, how we built it, and its early outcomes. METHODS: We began by codesigning the mission, vision, objectives, and values. We then established the structure for leadership and network management to provide a functional uniformity and sustainability. Virtual meetings with network members and strategic in-person gatherings optimized the use of the time and resources of the network. RESULTS: The network has seen good participation by members and candidates for membership, who have provided feedback on case-based learning. Members have attended training sessions on quality improvement, research in human subjects, and IC&P in pediatric oncology at national and regional meetings and workshops. Network members have presented their work at regional and global meetings, and publications are beginning to emerge from this community. A direct effect of the Prevencionistas e Infectólogos para Cáncer Pediátrico en América Latina network has been the creation of a similar network for the Asia Pacific region, and a third network is being planned. CONCLUSION: We have demonstrated the power of a discipline-specific network structure to facilitate sharing of evidence-based information that enhances the quality-of-care delivery in pediatric oncology.

Changes in the incidence of acute bacterial meningitis caused by Streptococcus pneumoniae and the implications of serotype replacement in children in Colombia after mass vaccination with PCV10.

Introduction: Acute bacterial meningitis (ABM) is a public health problem. The disease has reemerged after the introduction of pneumococcal conjugate vaccines (PCVs) due to an increase in serotypes that are not covered. The objective was to determine the changes in the disease incidence before and after the introduction of the 10-valent vaccine (PCV10) in Colombia. Methods: This multicenter study was conducted in 17 hospitals in Colombia. Data were collected from January 2008 to December 2019 in 10 hospitals in Bogotá and from January 2017 to December 2019 in seven hospitals in Cali, Medellín and Cartagena. The data were grouped into three periods: 2008-2011, 2012-2015, and 2016-2019. Results: Of the 706 cases of invasive pneumococcal disease, 81 (11.4%) corresponded to meningitis. The relative incidence in Bogotá in the first period was 0.6 per 100,000 patients ≤ 5 years, decreased to 0.4 per 100,000 patients ≤ 5 years in the second period and increased in the third period to 0.7 per 100,000 patients ≤ 5 years. Serotypes covered by PCV10 decreased from 75 to 9.1%, with Spn19A (31.8%) and Spn34 (13.6%) emerging in the third period. Increased resistance to penicillin (13 to 37%) and to ceftriaxone (5.9 to 16%) was due to the emergence of multidrug-resistant Spn19A. The total mortality rate was 23.5% and increased from 12 to 33%. Conclusions: ABM due to pneumococcus has high morbidity and mortality rates. Reemergence of the disease has been observed due to the inclusion of polymerase chain reaction (PCR) for diagnosis and replacement of circulating serotypes after the introduction of PCV10, with an increase in Spn19A, which causes death and exhibits antimicrobial resistance. Continued surveillance is needed.

Answers to common questions about COVID-19 vaccines in children with cancer.

BACKGROUND: The SARS-CoV-2 outbreak in 2020 evolved into a global pandemic, and COVID-19 vaccines became rapidly available, including for pediatric patients. However, questions emerged that challenged vaccine acceptance and use. We aimed to answer these questions and give recommendations applicable for use in pediatric patients with cancer by healthcare professionals and the public. METHODS: A 12-member global COVID-19 Vaccine in Pediatric Oncology Working Group made up of physicians and nurses from all world regions met weekly from March to July 2021. We used a modified Delphi method to select the top questions. The Working Group, in four-member subgroups, answered assigned questions by providing brief recommendations, followed by a discussion of the rationale for each answer. All Working Group members voted on each recommendation using a scale of 1 to 10, 10 being complete agreement. A "pass" recommendation corresponded to an agreement ≥7.5. RESULTS: We selected 15 questions from 173 suggested questions. Based on existing published information, we generated answers for each question as recommendations. The overall average agreement for the 24 recommendations was 9.5 (95% CI 9.4-9.6). CONCLUSION: Top COVID-19 vaccine-related questions could be answered using available information. Reports on COVID-19 vaccination and related topics have been published at record speed, aided by available technology and the priority imposed by the pandemic; however, all efforts were made to incorporate emerging information throughout our project. Recommendations will be periodically updated on a dedicated website.

Factors associated to the duration of COVID-19 lockdowns in Chile.

During the first year of the COVID-19 pandemic, several countries have implemented non-pharmacologic measures, mainly lockdowns and social distancing, to reduce the spread of the SARS-CoV-2 virus. These strategies varied widely across nations, and their efficacy is currently being studied. This study explores demographic, socioeconomic, and epidemiological factors associated with the duration of lockdowns applied in Chile between March 25th and December 25th, 2020. Joint models for longitudinal and time-to-event data were used. In this case, the number of days under lockdown for each Chilean commune and longitudinal information were modeled jointly. Our results indicate that overcrowding, number of active cases, and positivity index are significantly associated with the duration of lockdowns, being identified as risk factors for longer lockdown duration. In short, joint models for longitudinal and time-to-event data permit the identification of factors associated with the duration of lockdowns in Chile. Indeed, our findings suggest that demographic, socioeconomic, and epidemiological factors should be used to define both entering and exiting lockdown.

Differences Between Methicillin-susceptible Versus Methicillin-resistant Staphylococcus aureus Infections in Pediatrics: Multicenter Cohort Study Conducted in Bogotá, Colombia, 2014-2018.

BACKGROUND: The epidemiology of methicillin-resistant Staphylococcus aureus (MRSA) and methicillin-susceptible S. aureus (MSSA) has changed in recent years. The present article is intended to establish differences between clinical, laboratory and imaging findings and outcomes of MSSA and MRSA infections, as well as among subgroups of infection such as skin and soft tissue infection, osteoarticular, bacteremia or pneumonia in a pediatric population from Bogota, Colombia. METHODS: Retrospective cohort study using clinical records of patients under 18 years of age treated at the participating centers in Bogota, Colombia, between 2014 and 2018. The first positive S. aureus culture was studied. MSSA and MRSA were compared. The χ2 test, Fisher exact test, and Kruskal-Wallis test were calculated, and the statistical significance was presented using the difference and its 95% CI. RESULTS: Five hundred fifty-one patients were included; 211 (38%) corresponded to MRSA and 340 (62%) to MSSA for a total of 703 cultures. A significantly higher probability of having an MSSA infection than MRSA was found in patients with previous heart disease (3.3% vs. 0.5%), neurologic disease (5.9% vs. 2.5%), recent major surgeries (11% vs. 5%) or who has an implanted device (11% vs. 4%). In contrast, in severe MRSA infections (bacteremia, osteoarticular infections and pneumonia), a higher rate of complications was seen (admission to the pediatric intensive care unit, mechanical ventilation and vasoactive support), and in osteoarticular MRSA, more than 1 surgery per case was seen (89% vs. 61%). Laboratory results and mortality were similar. CONCLUSIONS: MRSA was associated with a more severe course in bacteremia, osteoarticular infections and pneumonia. Some classical risk factors associated with MRSA infections were found to be related to MSSA. In general, with the exception of skin and soft tissue infection, there was an increased risk of pediatric intensive care unit admission and mechanical and inotropic support with MRSA in a pediatric population.

Distributions of the HLA-A, HLA-B, HLA-C, HLA-DRB1, and HLA-DQB1 alleles and haplotype frequencies of 1763 stem cell donors in the Colombian Bone Marrow Registry typed by next-generation sequencing.

The HLA compatibility continues to be the main limitation when finding compatible donors, especially if an identical match is not found within the patient's family group. The creation of bone marrow registries allowed a therapeutic option by identifying 10/10 compatible unrelated donors (URD). However, the availability and frequency of haplotypes and HLA alleles are different among ethnic groups and geographical areas, increasing the difficulty of finding identical matches in international registries. In this study, the HLA-A, -B, -C, -DRB1, and -DQB1 loci of 1763 donors registered in the Colombian Bone Marrow Registry were typed by next-generation sequencing. A total of 52 HLA-A, 111 HLA-B, 41 HLA-C, 47 HLA-DRB1, and 20 HLA-DQB1 alleles were identified. The 3 most frequent alleles for each loci were A*24:02g (20,8%), A*02:01g (16,1%), A*01:01g (7.06%); B*35:43g (7.69%), B*40:02g (7.18%), B*44:03g (6.07%); C*04:01g (15.40%), C*01:02g (10.49%), C*07:02g (10.44%); DRB1*04:07g (11.03%), DRB1*07:01g (9.78%), DRB1*08:02g (6.72%); DQB1*03:02g (20.96%), DQB1*03:01g (17.78%) and DQB1*02:01g (16.05%). A total of 497 HLA-A-C-B-DRB1-DQB1 haplotypes were observed with a frequency greater than or equal to 0.05% (> 0.05%); the haplotypes with the highest frequency were A*24:02g~B*35:43g~C*01:02g~DQB1*03:02g~DRB1*04:07g (3.34%), A*29:02g~B*44:03g~C*16:01g~DQB1*02:01g~DRB1*07:01g (2.04%), and A*01:01g~B*08:01g~C*07:01g~DQB1*02:01g~DRB1*03:01g (1.83%). This data will allow the new Colombian Bone Marrow Donor Registry to assess the genetic heterogeneity of the Colombian population and serve as a tool of interest for future searches of unrelated donors in the country.

Migration of liquid silicone, an emerging contraindication of neuraxial anesthesia / Migración de silicona líquida, una contraindicación emergente de la anestesia neuroaxial

Abstract The illegal use of liquid silicone products or biopolymers in gluteal augmentation procedures is giving rise to multiple complications, with a significant negative health impact, both in the short and long-term. The migration of polymers to the sacral and lumbar region represents a major limitation to conducting neuraxial anesthesia procedures. This silicon migration is unpredictable through the superficial tissue as is widely described in the literature. Caudal, spinal and epidural anesthesia may cross the silicone in the fascia and contaminate the neural axis with substances that are highly capable of causing inflammation, edema and tissue necrosis. In order to improve the safety of neuraxial anesthetic procedures and avoid the potential risk of dissemination and contamination of the neural axis, this complication must be ruled out, or be considered an emerging contraindication for these anesthetic procedures.

Resumen La aplicación ilegal de productos como silicona líquida o biopolímeros en procedimientos de aumento de glúteos está generando múltiples complicaciones con gran impacto negativo para la salud tanto a corto como a largo plazo. La migración de polímeros a la región sacra y lumbar representa una importante limitación para la realización de procedimientos de anestesia neuroaxial. Esta migración de silicona es impredecible a través del tejido superficial, la cual está ampliamente descrita en la literatura. Los procedimientos anestésicos caudal, espinal y epidural podrían atravesar los silicomas en la fascia del tejido y contaminar el neuroeje con sustancias con alta capacidad de generar inflamación, edema y necrosis de tejidos. Con el fin de aumentar la seguridad de los procedimientos anestésicos neuroaxiales y evitar el riesgo potencial de dispersión y contaminación del neuroeje, es necesario descartar esta complicación o considerar una contraindicación emergente en estos procedimientos anestésicos.

Monitoring HSP70 exosomes in cancer patients' follow up: a clinical prospective pilot study.

Exosomes are nanovesicles released by all cells that can be found in the blood. A key point for their use as potential biomarkers in cancer is to differentiate tumour-derived exosomes from other circulating nanovesicles. Heat shock protein-70 (HSP70) has been shown to be abundantly expressed by cancer cells and to be associated with bad prognosis. We previously showed that exosomes derived from cancer cells carried HSP70 in the membrane while those from non-cancerous cells did not. In this work, we opened a prospective clinical pilot study including breast and lung cancer patients to determine whether it was possible to detect and quantify HSP70 exosomes in the blood of patients with solid cancers. We found that circulating exosomal HSP70 levels, but not soluble HSP70, reflected HSP70 content within the tumour biopsies. Circulating HSP70 exosomes increased in metastatic patients compared to non-metastatic patients or healthy volunteers. Further, we demonstrated that HSP70-exosome levels correlated with the disease status and, when compared with circulating tumour cells, were more sensitive tumour dissemination predictors. Finally, our case studies indicated that HSP70-exosome levels inversely correlated with response to the therapy and that, therefore, monitoring changes in circulating exosomal HSP70 might be useful to predict tumour response and clinical outcome.

Emergence of Streptococcus pneumoniae serotype 19A (Spn19A) in the pediatric population in Bogotá, Colombia as the main cause of invasive pneumococcal disease after the introduction of PCV10.

Introduction: With the use of pneumococcal conjugate vaccines(PCV), the behavior of invasive pneumococcal disease(IPD) has changed relative to serotype distribution. The introduction of these vaccines in national immunization programs has reduced the incidence of IPD, with a marked decrease in the circulation of the serotypes included in the vaccine used in each country. However, the subsequent emergence of other serotypes not included in the vaccine, such 19A in case of PCV7 and PCV10, has been documented. Materials and methods: This was case series study (2008-2017) in pediatric patients admitted to 10 hospitals in Bogota who were diagnosed with IPD. It was conducted during the transitional period of implementing the PCV10 vaccine in Colombia in 2012. Cases of bacteremic pneumococcal pneumonia, meningitis, primary bacteremia and osteoarticular infection were included. A descriptive analysis of the demographic, clinical and laboratory variables of patients with IPD by Spn19A, its trend over time, profiles of antimicrobial susceptibility and clinical outcomes was performed. Results: There were 463 cases of IPD, 315(68%) with known serotypes. The prevalence of IPD by Spn19A was 17.7%(56 cases), tending to increase over time. During 2008-2011, the prevalence was 4.4%, and during 2014-2017, it was 32.4%, The most frequent diagnosis was pneumonia(80.4%). In nonmeningeal isolates, 39.6% were not susceptible to penicillin. An increase in the resistance was observed over time. Conclusion: Spn19A is a prevalent cause of IPD in the pediatric population of the analyzed cohort, with an increasing trend of this serotype during the surveillance period after the introduction of PCV10, being the most common serotype identified in recent years.

Human Leukocyte Antigen and Red Blood Cells Impact Umbilical Cord Blood CD34+ Cell Viability after Thawing.

Hematopoietic progenitor cell (HPC) transplantation is a treatment option for malignant and nonmalignant diseases. Umbilical cord blood (UCB) is an important HPC source, mainly for pediatric patients. It has been demonstrated that human leukocyte antigen (HLA) matching and cell dose are the most important features impacting clinical outcomes. However, UCB matching is performed using low resolution HLA typing and it has been demonstrated that the unnoticed mismatches negatively impact the transplant. Since we found differences in CD34+ viability after thawing of UCB units matched for two different patients (p = 0.05), we presumed a possible association between CD34+ cell viability and HLA. We performed a multivariate linear model (n = 67), comprising pre-cryopreservation variables and high resolution HLA genotypes separately. We found that pre-cryopreservation red blood cells (RBC), granulocytes, and viable CD34+ cell count significantly impacted CD34+ viability after thawing, along with HLA-B or -C (R2 = 0.95, p = 0.01; R2 = 0.56, p = 0.007, respectively). Although HLA-B*40:02 may have a negative impact on CD34+ cell viability, RBC depletion significantly improves it.

Distinctive ligand-binding specificities of tandem PA14 biomass-sensory elements from Clostridium thermocellum and Clostridium clariflavum.

Cellulolytic clostridia use a highly efficient cellulosome system to degrade polysaccharides. To regulate genes encoding enzymes of the multi-enzyme cellulosome complex, certain clostridia contain alternative sigma I (σI ) factors that have cognate membrane-associated anti-σI factors (RsgIs) which act as polysaccharide sensors. In this work, we analyzed the structure-function relationship of the extracellular sensory elements of Clostridium (Ruminiclostridium) thermocellum and Clostridium clariflavum (RsgI3 and RsgI4, respectively). These elements were selected for comparison, as each comprised two tandem PA14-superfamily motifs. The X-ray structures of the PA14 modular dyads from the two bacterial species were determined, both of which showed a high degree of structural and sequence similarity, although their binding preferences differed. Bioinformatic approaches indicated that the DNA sequence of promoter of sigI/rsgI operons represents a strong signature, which helps to differentiate binding specificity of the structurally similar modules. The σI4 -dependent C. clariflavum promoter sequence correlates with binding of RsgI4_PA14 to xylan and was identified in genes encoding xylanases, whereas the σI3 -dependent C. thermocellum promoter sequence correlates with RsgI3_PA14 binding to pectin and regulates pectin degradation-related genes. Structural similarity between clostridial PA14 dyads to PA14-containing proteins in yeast helped identify another crucial signature element: the calcium-binding loop 2 (CBL2), which governs binding specificity. Variations in the five amino acids that constitute this loop distinguish the pectin vs xylan specificities. We propose that the first module (PA14A ) is dominant in directing the binding to the ligand in both bacteria. The two X-ray structures of the different PA14 dyads represent the first reported structures of tandem PA14 modules.

Alternative σI/anti-σI factors represent a unique form of bacterial σ/anti-σ complex.

The σ70 family alternative σI factors and their cognate anti-σI factors are widespread in Clostridia and Bacilli and play a role in heat stress response, virulence, and polysaccharide sensing. Multiple σI/anti-σI factors exist in some lignocellulolytic clostridial species, specifically for regulation of components of a multienzyme complex, termed the cellulosome. The σI and anti-σI factors are unique, because the C-terminal domain of σI (SigIC) and the N-terminal inhibitory domain of anti-σI (RsgIN) lack homology to known proteins. Here, we report structure and interaction studies of a pair of σI and anti-σI factors, SigI1 and RsgI1, from the cellulosome-producing bacterium, Clostridium thermocellum. In contrast to other known anti-σ factors that have N-terminal helical structures, RsgIN has a ß-barrel structure. Unlike other anti-σ factors that bind both σ2 and σ4 domains of the σ factors, RsgIN binds SigIC specifically. Structural analysis showed that SigIC contains a positively charged surface region that recognizes the promoter -35 region, and the synergistic interactions among multiple interfacial residues result in the specificity displayed by different σI/anti-σI pairs. We suggest that the σI/anti-σI factors represent a distinctive mode of σ/anti-σ complex formation, which provides the structural basis for understanding the molecular mechanism of the intricate σI/anti-σI system.

HLA-A, -B, -C, -DRB1 and -DQB1 allele and haplotype frequencies of 1463 umbilical cord blood units typed in high resolution from Bogotá, Colombia.

Allele and haplotype frequencies were calculated from 1463 umbilical cord blood (UCB) units, from Bogotá (Colombia) donors, HLA-typed in high resolution. This is the first report using allele-level typed colombian samples of five HLA loci related to hematopoietic stem cell transplantation (HLA-A, -B, -C, -DRB1 and -DQB1). The most frequent haplotype found in our sample was A*24:02g ∼ B*35:43g ∼ C*01:02g ∼ DRB1*04:07g ∼ DQB1*03:02g (4.14%). Our data are available at the Allele Frequencies Net Database under the code AFND3604.

Regulation of biomass degradation by alternative σ factors in cellulolytic clostridia.

Bacteria can adjust their genetic programs via alternative σ factors to face new environmental pressures. Here, we analyzed a unique set of paralogous alternative σ factors, termed σIs, which fine-tune the regulation of one of the most intricate cellulolytic systems in nature, the bacterial cellulosome, that is involved in degradation of environmental polysaccharides. We combined bioinformatics with experiments to decipher the regulatory networks of five σIs in Clostridium thermocellum, the epitome of cellulolytic microorganisms, and one σI in Pseudobacteroides cellulosolvens which produces the cellulosomal system with the greatest known complexity. Despite high homology between different σIs, our data suggest limited cross-talk among them. Remarkably, the major cross-talk occurs within the main cellulosomal genes which harbor the same σI-dependent promoter elements, suggesting a promoter-based mechanism to guarantee the expression of relevant genes. Our findings provide insights into the mechanisms used by σIs to differentiate among their corresponding regulons, representing a comprehensive overview of the regulation of the cellulosome to date. Finally, we show the advantage of using a heterologous host system for analysis of multiple σIs, since information generated by their analysis in their natural host can be misinterpreted owing to a cascade of interactions among the different σIs.

Diferencias en la aplicación de estrategias de afrontamiento adolescente entre alumnos hombres y mujeres del nivel medio superior / Differences in the implementation of adolescent coping strategies between men and women students upper level environment

La adolescencia está caracterizada por cambios tanto físicos como psicológicos y tiene como resultado la identidad y la madurez requeridas para la edad adulta. Los adolescentes inician una etapa de situaciones a las cuales deben dar respuesta, siendo el contexto escolar solo uno de los escenarios en los cuales ellos manifiestan su forma de afrontar las problemáticas o situaciones cotidianas. El afrontamiento ha sido estudiado por diversos autores. Esta investigación está sustentada en la propuesta de Frydenberg y Lewis (1993) que postula al afrontamiento como un proceso cognitivo y afectivo que permite a la persona responder de manera particular a un estímulo y esta respuesta a su vez le permite la adaptación social de acuerdo a su contexto. El objetivo del estudio realizado fue comparar los estilos y las estrategias de afrontamiento adolescente de acuerdo al sexo. Se trabajó con una muestra de estudiantes del nivel medio superior de una escuela pública del Estado de México (México). El rango de edad fue de 15-16 años con un promedio de 15.28 +- .48, siendo 268 hombres y 367 mujeres. Se aplicó la Escala de Afrontamiento para Adolescentes de Frydenberg y Lewis (1993). Los resultados presentan diferencias significativas en los estilos con respecto al sexo, ya que en los hombres es el estilo que presenta las medias más altas, y un puntaje de 70 a 89 indica que éste se emplea a menudo. También se encontraron diferencias en algunas de las estrategias de afrontamiento. Lo anterior permitió concluir que en los adolescentes la manera de afrontar sus problemas está relacionada con sus vivencias pasadas y el afrontamiento es una manera de autorregulación, corroborando así las diferencias del uso de afrontamiento entre hombres y mujeres adolescentes.

Adolescence is the stage that is characterized by both physical and psychological changes that will result in the identity and maturity required for adulthood. The adolescents begin a stage of situations to which to respond, being the school context only one of the scenarios in which they manifest their way of facing the problems or everyday situations. In this,as in all contexts, adolescents need to have personal resources that allow them to cope with problems and reduce stress. Coping has been studied from several authors, so this research is based on the proposal of Frydenberg and Lewis (1993) which postulate coping as a cognitive and affective process that allows the person to respond in a particular way to a stimulus and this answer in turn will allow you or not the social adaptation according to its context. It has been pointed out that while coping is dynamic, not all forms of coping can be the best, everything will depend on the moment and what is faced. However, the more unproductive the ways of coping, the mental health of the adolescent and of every individual will be negatively affected. The coping for Frydenberg and Lewis (1993) is divided in three same styles that derive in 18 strategies. Coping is considered with reference to the problem as the type of coping that allows to give solution and to diminish the tension. With respect to coping with others this will allow the search for support in others that allow to decrease the tension and with that to pretend the problem. And finally the non-productive coping that refers to only reducing tension but not solving the problem and even leads to self-incrimination. The objective of the study was to compare styles and strategies of adolescent coping according to sex. For this purpose we worked with a sample of students of the upper middle level of public school of the State of Mexico, Mexico. The age range was 15-16 years with an average of 15.28 +- .48, with 268 men and 367 women. The Frydenberg and Lewis Teen Coping Scale (1993) was applied. The results showed significant differences in problem solving and non-productive styles. While the reference style to others did not differ in sex, differences were found in some coping strategies, noting that women employed more non-productive strategies than men, and it was corroborated that men tended to To employ more strategies that correspond to the problem-solving style, as is the case of physical distraction and relaxing amusements that has been a factor reported in several studies. This allowed us to conclude that in adolescents the way to face their problems is related to their past experiences and coping is a way of self-regulation. Corroborating the differences in the use of coping among adolescent men and women. In addition to allowing new lines of research to be proposed that favorably impact not only on the school context of the student but in all its surroundings. Considering that if the confrontation is not unique and static, but that this is going to be exercised according to the situation and the previous experiences, one would have to contemplate the relation with the mental health. Pointing to this last aspect, since the theoretical contributions point out that when it is not adequately addressed, it puts at risk mental health and reflects the lack of psychological resources to handle life. It would be necessary to investigate more about the social demands of gender role, since when differences are found between men and women, this becomes a factor worthy of being studied, but no longer as being a man or a woman but about the behaviors allowed according to the role of socially assigned gender.

Culturable Facultative Methylotrophic Bacteria from the Cactus Neobuxbaumia macrocephala Possess the Locus xoxF and Consume Methanol in the Presence of Ce3+ and Ca2.

Methanol-consuming culturable bacteria were isolated from the plant surface, rhizosphere, and inside the stem of Neobuxbaumia macrocephala. All 38 isolates were facultative methylotrophic microorganisms. Their classification included the Classes Actinobacteria, Sphingobacteriia, Alpha-, Beta-, and Gammaproteobacteria. The deduced amino acid sequences of methanol dehydrogenase obtained by PCR belonging to Actinobacteria, Alpha-, Beta-, and Gammaproteobacteria showed high similarity to rare-earth element (REE)-dependent XoxF methanol dehydrogenases, particularly the group XoxF5. The sequences included Asp301, the REE-coordinating amino acid, present in all known XoxF dehydrogenases and absent in MxaF methanol dehydrogenases. The quantity of the isolates showed positive hybridization with a xoxF probe, but not with a mxaF probe. Isolates of all taxonomic groups showed methylotrophic growth in the presence of Ce3+ or Ca2+. The presence of xoxF-like sequences in methylotrophic bacteria from N. macrocephala and its potential relationship with their adaptability to xerophytic plants are discussed.