Epidemiological and microbiological characteristics of S. aureus pediatric infections in Colombia 2018-2021, a national multicenter study (Staphylored Colombia).

Background: Staphylococcus aureus infections are a significant cause of morbidity and mortality in pediatric populations worldwide. The Staphylo Research Network conducted an extensive study on pediatric patients across Colombia from 2018 to 2021. The aim of this study was to describe the epidemiological and microbiological characteristics of S. aureus in this patient group. Methods: We analyzed S. aureus isolates from WHONET-reporting centers. An "event" was a positive culture isolation in a previously negative individual after 2 weeks. We studied center characteristics, age distribution, infection type, and antibiotic susceptibilities, comparing methicillin sensitive (MSSA) and resistant S. aureus (MRSA) isolates. Results: Isolates from 20 centers across 7 Colombian cities were included. Most centers (80%) served both adults and children, with 55% offering oncology services and 85% having a PICU. We registered 8,157 S. aureus culture isolations from 5,384 events (3,345 MSSA and 1,961 MRSA) in 4,821 patients, with a median age of 5 years. Blood (26.2%) and skin/soft tissue (18.6%) were the most common infection sources. Most isolates per event remained susceptible to oxacillin (63.2%), clindamycin (94.3%), and TMP-SMX (98.3%). MRSA prevalence varied by city (<0.001), with slightly higher rates observed in exclusively pediatric hospitals. In contrast, the MRSA rate was somewhat lower in centers with Antimicrobial Stewardship Program (ASP). MRSA was predominantly isolated from osteoarticular infections and multiple foci, while MSSA was more frequently associated with recurrent infections compared to MRSA. Conclusions: This is the largest study of pediatric S. aureus infections in Colombia. We found MSSA predominance, but resistance have important regional variations. S. aureus remains susceptible to other commonly used antibiotics such as TMP-SMX and clindamycin. Ongoing monitoring of S. aureus infections is vital for understanding their behavior in children. Prospective studies within the Staphylored LATAM are underway for a more comprehensive clinical and genetic characterization.

Spatial distribution of Triatoma dimidiata peridomestic colonies modulated by distance between susceptible microhabitat patches.

Triatoma dimidiata is a vector of the hemoparasite Trypanosoma cruzi, the causal agent of Chagas disease. It settles reproductive colonies in the peridomicile of the premises. The peridomicile is comprised of a random set of artificial and natural features that overlap and assemble a network of microenvironmental suitable sites (patches) that interact with each other and favor the structure and proliferation of T. dimidiata colonies. The heterogeneity of patch characteristics hinders the understanding and identification of sites susceptible to colonization. In this study, a classification system using a random forest algorithm was used to identify peridomiciles susceptible to colonization to describe the spatial distribution of these sites and their relationship with the colonies of T. dimidiata in ten localities of Yucatan. From 1,000 peridomiciles reviewed, the classification showed that 13.9 % (139) of the patches were highly susceptible (HSP), and 86.1 % (861) were less susceptible (LSP). All localities had at least one HSP. The occupancy by patch type showed that the percentage of total occupancy and by colonies was higher in the HSP, while the occupancy by adult T. dimidiata without evidence of nymphs or exuviae (propagules) was higher in the LSP. A generalized additive model (GAM) revealed that the percentage of occupied patches increases as the abundance of individuals in the localities increases however, the percentage of occupied patches in LSP is lower than occupied in HSP. Distance analyses revealed that colonies and propagules were located significantly closer (approximately 200 m) to a colony in a HSP than any colony in a LSP. The distribution of T. dimidiata in the localities was defined by the distribution of patch type; as the occupancy in these patches increased, a network of peridomestic populations was configured, which may be promoted by a greater abundance of insects inside the localities. These results reveal that the spatial distribution of T. dimidiata individuals and colonies in the peridomicile at the locality scale corresponds to a metapopulation pattern within the localities through a system of patches mediated by distance and level of the vectors' occupancy.

Empleo de antibióticos en cirugía electiva en el adulto mayor / Antibiotic Use for Elective Surgery in the Older Adult

Introducción: Los pacientes quirúrgicos geriátricos tienen afectación funcional y enfermedades asociadas, lo cual aumenta su riesgo quirúrgico con la edad. Objetivo: Determinar el comportamiento del uso de los antibióticos en pacientes geriátricos que requieren cirugía electiva atendidos en el Hospital Vladimir Ilich Lenin del 2018 al 2022. Métodos: Se realizó un estudio descriptivo, observacional, analítico y transversal a pacientes intervenidos por cirugía electiva con tratamiento con antibiótico. Los datos se obtuvieron de las historias clínicas y la entrevista aplicada. Se analizaron variables como edad, sexo, enfermedades asociadas, diagnóstico preoperatorio, tiempo quirúrgico, complicaciones, evolución, filtrado glomerular y dosis antibiótica perioperatoria. Resultados: El empleo de antibióticos fue más utilizado en los grupos de edades de 60 a 64 años y el sexo femenino; las comorbilidades que predominaron fueron la diabetes mellitus, la hipertensión arterial y la cardiopatía isquémica. Los motivos de consulta más frecuentes fueron por litiasis vesicular y por hernias dentro del grupo ASA I de la American Society of Anesthesiologists. Los antibióticos fundamentales fueron con dosis ajustada. Conclusiones: Se necesita de un trabajo diferenciado en cuanto a la atención al adulto mayor. La utilización de un protocolo o algoritmo de trabajo es necesario en la práctica diaria, sobre todo ante la necesidad de una cirugía electiva(AU)

Introduction: Geriatric surgical patients have functional impairment and associated diseases, which increases their surgical risk with age. Objective: To determine the behavior of antibiotic use in geriatric patients requiring elective surgery attended at Hospital Vladimir Ilich Lenin Hospital from 2018 to 2022. Methods: A descriptive, observational, analytical and cross-sectional study was conducted on patients undergoing elective surgery with antibiotic treatment. The data were obtained from medical records and the applied interview. The analyzed variables included age, sex, associated diseases, preoperative diagnosis, surgical time, complications, evolution, glomerular filtration and perioperative antibiotic dose. Results: Antibiotic use was more frequent in the age group 60 to 64 years and in the female sex; the most frequent comorbidities were diabetes mellitus, arterial hypertension and ischemic heart disease. The most frequent reasons for consultation were vesicular lithiasis and hernias within the ASA I group of the American Society of Anesthesiologists. The fundamental antibiotics were adjusted by doses. Conclusions: An individualized work is needed in terms of care of the older adult. The use of a working protocol or algorithm is necessary in daily practice, especially when elective surgery is required(AU)

Transcriptome profile in heat resilient Pacific oyster Crassostrea gigas families under thermal challenge.

Since the introduction of the Pacific oyster Crassostrea gigas in Baja California Sur, Mexico, its culture has faced environmental challenges, specifically increasing temperatures that result in high mortalities. The inter-tidal zone seawater temperature during a year at the Baja California Peninsula broadly ranges from 7 °C to 39 °C. Therefore, to understand how oysters respond to heat stress during daily temperature oscillations, heat-resistant (RR, father, and mother resistant) and heat-susceptible (SS, both parents susceptible) phenotypes families from a C. gigas breeding program were exposed to a thermal challenge. Based on a laboratory-simulated daily oscillatory thermal challenge (26 to 34 °C) for 30 days, RR phenotype presented differences compared to SS phenotype since the beginning (day 0) of the thermal challenge. Gene expression analyses revealed 1822 differentially expressed up-regulated transcripts in RR, related to functions of metabolic processes, biological regulation, and response to stimulus and signaling. At the end of the experiment (day 30), 2660 differentially expressed up-regulated transcripts were identified in RR. Functional analysis of the genes expressed indicates responses of regulation of biological processes and response to a stimulus. Additionally, 340 genes were differentially expressed among RR vs. SS from the beginning to the end of the thermal challenge, where 170 genes were up-regulated, and 170 were down-regulated. These transcriptomic profiles represent the first report to identify gene expression markers associated with RR phenotypes for the Pacific oyster to the future broodstock selection.

To tolerate drought or resist aphids? A new challenge to plant science is on the horizon.

Aphids are important herbivorous insects that can cause significant crop damage, leading to yield reduction and economic loss. One avenue being explored to reduce aphid impacts is the development of aphid-resistant plants. Under projected climate scenarios, it is expected that plants will be exposed to greater biotic and abiotic stress, including increased herbivorous insect infestation and exposure to prolonged periods of environmental stress, particularly drought. In response to these projections, plant-aphid interactions under drought conditions have been a subject of growing interest; however, few studies have looked at the impact of drought stress on plant resistance to aphids despite the potential importance for plant breeding. Here, we examine the latest scientific advances regarding variation in plant resistance to aphids under drought, emphasizing underlying mechanisms and functional trade-offs and propose a conceptual model relating plant tolerance to drought with plant resistance to aphids.

Biofilm-forming microorganisms causing hospital-acquired infections from intravenous catheter: A systematic review.

The high prevalence of nosocomial infections is related to the use of medical insertion devices such as central venous catheters (CVCs). Most of the microorganisms causing nosocomial infections are biofilm producers, this characteristic allows them to adhere to abiotic surfaces and cause initial catheter infections that can lead to bloodstream infections. Our main goal in this systematic review was to evaluate the prevalence of biofilm among CVC-related infections, particularly among Intensive Care Unit (ICU) patients, in the studies applying different in vitro and in vivo methodologies. All studies reporting clinical isolates from patients with catheter-related nosocomial infections and biofilm evaluation published up to 24 June 2022 in the PubMed and Scopus databases were included. Twenty-five studies met the eligibility criteria and were included in this systematic review for analysis. Different methodologies were applied in the assessment of biofilm-forming microorganisms including in vitro assays, catheter-infected in vitro, and in vivo mouse models. The present study showed that between 59 and 100% of clinical isolates were able to form biofilms, and the prevalence rate of biofilm formation varied significantly between studies from different countries and regions. Among the clinical isolates collected in our study set, a wide variety of microorganisms including Gram-positive strains, Gram-negative strains, and Candida albicans were found. Many authors studied resistance mechanisms and genes related to biofilm development and surface adherence properties. In some cases, the studies also evaluated biofilm inhibition assays using various kinds of catheter coatings.

Ceftaroline as salvage therapy for methicillin susceptible Staphylococcus aureus complicated bacteremia.

Infections caused by methicillin-susceptible Staphylococcus aureus (MSSA) are still associated with significant morbidity and mortality. Treatment failures of cefazolin (CFZ) have been reported and probably related to the inoculum effect. New treatments for severe MSSA infections are needed and ceftaroline fosamil (CPT) could be an option. Our aim was to describe the clinical characteristics of five patients with complicated MSSA bacteremia failing CFZ and successfully treated with CPT. We performed a retrospective chart review in a Hospital in Buenos Aires, Argentina; in a 12-month period, five patients (24%) of 21 with MSSA bacteremia experienced CFZ failure and were salvaged with CPT. The median time of CFZ therapy was 10 days before changing to CPT; four patients had evidence of metastatic spread and 2 had endocarditis. All patients experienced microbiological and clinical cure with CPT, which was used as monotherapy in 4 and in combination with daptomycin in another. One patient discontinued CPT due to neutropenia on day 23 of treatment. In patients with MSSA BSI failing current therapy, CPT could be a good therapeutic option.

Las infecciones causadas por Staphylococcus aureus sensible a la meticilina (SASM) todavía se asocian con una morbilidad y mortalidad significativas. Se han informado fallas en el tratamiento de cefazolina (CFZ) probablemente relacionadas con efecto inóculo. Nuevos tratamientos son necesarios para estas infecciones y ceftarolina fosamil (CPT) podría ser una opción. Nuestro objetivo fue describir las características clínicas de cinco pacientes con bacteriemia por SASM complicada con falla a CFZ y que fueron exitosamente tratados con CPT. Realizamos una revisión retrospectiva de historias clínicas en un hospital de Buenos Aires, Argentina; en un período de 12 meses, cinco pacientes (24%) de 21 con bacteriemia por SASM experimentaron falla a CFZ y fueron tratados con CPT. La mediana de tiempo de la terapia con CFZ fue de 10 días antes de cambiar a CPT; cuatro pacientes presentaban evidencia de diseminación metastásica y 2 tenían endocarditis. Todos los pacientes experimentaron curación microbiológica y clínica con CPT, que se utilizó como monoterapia en 4 y en combinación con daptomicina en otro. Un paciente interrumpió CPT debido a neutropenia el día 23 de tratamiento. En enfermos con infecciones graves por SASM que fallan en la terapia actual, CPT podría ser una buena opción terapéutica.

Ceftaroline as salvage therapy for methicillin susceptible staphylococcus aureus complicated bacteremia / Ceftarolina como tratamiento de rescate para la bacteriemia complicada por Staphylococcus aureus sensible a la meticilina

Abstract Infections caused by methicillin-susceptible Staphylococcus aureus (MSSA) are still associated with significant morbidity and mortality. Treatment failures of cefazolin (CFZ) have been reported and probably related to the inoculum effect. New treatments for severe MSSA infections are needed and ceftaroline fosamil (CPT) could be an option. Our aim was to describe the clinical characteristics of five patients with com plicated MSSA bacteremia failing CFZ and successfully treated with CPT. We performed a retrospective chart review in a Hospital in Buenos Aires, Argentina; in a 12-month period, five patients (24%) of 21 with MSSA bacteremia experienced CFZ failure and were salvaged with CPT. The median time of CFZ therapy was 10 days before changing to CPT; four patients had evidence of metastatic spread and 2 had endocarditis. All patients experienced microbiological and clinical cure with CPT, which was used as monotherapy in 4 and in combination with daptomycin in another. One patient discontinued CPT due to neutropenia on day 23 of treatment. In patients with MSSA BSI failing current therapy, CPT could be a good therapeutic option.

Resumen Las infecciones causadas por Staphylococcus aureus sensible a la meticilina (SASM) todavía se asocian con una morbilidad y mortalidad significativas. Se han informado fallas en el tratamiento de cefazolina (CFZ) probablemente relacionadas con efecto inóculo. Nuevos tratamientos son necesarios para estas infecciones y ceftarolina fosamil (CPT) podría ser una opción. Nuestro objetivo fue describir las características clínicas de cinco pacientes con bacteriemia por SASM complicada con falla a CFZ y que fueron exitosamente tratados con CPT. Realizamos una revisión retrospectiva de historias clínicas en un hospital de Buenos Aires, Argentina; en un período de 12 meses, cinco pacientes (24%) de 21 con bacteriemia por SASM experimentaron falla a CFZ y fueron tratados con CPT. La mediana de tiempo de la terapia con CFZ fue de 10 días antes de cambiar a CPT; cuatro pacientes presentaban evidencia de diseminación metastásica y 2 tenían endocarditis. Todos los pacientes experimen taron curación microbiológica y clínica con CPT, que se utilizó como monoterapia en 4 y en combinación con daptomicina en otro. Un paciente interrumpió CPT debido a neutropenia el día 23 de tratamiento. En enfermos con infecciones graves por SASM que fallan en la terapia actual, CPT podría ser una buena opción terapéutica.

Seed Transmission of Pathogens: Non-Canonical Immune Response in Arabidopsis Germinating Seeds Compared to Early Seedlings against the Necrotrophic Fungus Alternaria brassicicola.

The transmission of seed-borne pathogens by the germinating seed is responsible for major crop diseases. The immune responses of the seed facing biotic invaders are poorly documented so far. The Arabidopsis thaliana/Alternaria brassicicola patho-system was used to describe at the transcription level the responses of germinating seeds and young seedling stages to infection by the necrotrophic fungus. RNA-seq analyses of healthy versus inoculated seeds at 3 days after sowing (DAS), stage of radicle emergence, and at 6 and 10 DAS, two stages of seedling establishment, identified thousands of differentially expressed genes by Alternaria infection. Response to hypoxia, ethylene and indole pathways were found to be induced by Alternaria in the germinating seeds. However, surprisingly, the defense responses, namely the salicylic acid (SA) pathway, the response to reactive oxygen species (ROS), the endoplasmic reticulum-associated protein degradation (ERAD) and programmed cell death, were found to be strongly induced only during the latter post-germination stages. We propose that this non-canonical immune response in early germinating seeds compared to early seedling establishment was potentially due to the seed-to-seedling transition phase. Phenotypic analyses of about 14 mutants altered in the main defense pathways illustrated these specific defense responses. The unexpected germination deficiency and insensitivity to Alternaria in the glucosinolate deficient mutants allow hypothesis of a trade-off between seed germination, necrosis induction and Alternaria transmission to the seedling. The imbalance of the SA and jasmonic acid (JA) pathways to the detriment of the JA also illustrated a non-canonical immune response at the first stages of the seedling.

The Dark Side of Shade: How Microclimates Drive the Epidemiological Mechanisms of Coffee Berry Disease.

Coffee berry disease (CBD) can cause significant coffee yield losses along with major income losses for African smallholders. Although these farmers cannot afford to purchase pesticides to control the disease, agroecological solutions have rarely been investigated, and how epidemiological mechanisms are linked to the environment of the coffee tree and the plot remains unclear. Agroforestry systems are a promising agroecological option, but the effect of shade on CBD regulation is the subject of debate, and the use of plant species diversity remains uncertain. Here, we address how shade affects epidemiological mechanisms by modifying the microclimate. For this purpose, we developed a mechanistic susceptible-exposed-infectious-removed model and used a Bayesian framework to infer the epidemiological parameters against microclimatic covariates. We show that shade has opposing effects on different epidemiological mechanisms. Specifically, shade can limit disease dynamics by reducing disease transmission while simultaneously promoting disease dynamics by reducing the latent period of the pathogen. However, in full sun, efficient disease transmission compensates for long latent periods. As a result, the balances between microclimatic variables can counterbalance the epidemiological rates, which can dramatically alter the fate of epidemics in shade versus full sun conditions. We propose research avenues to help design cost- and environmentally effective management strategies for CBD that are notably based on the functional traits of shade trees that could hamper CBD dispersal.

Taxonomical and functional bacterial community profiling in disease-resistant and disease-susceptible soybean cultivars.

Highly varied bacterial communities inhabiting the soybean rhizosphere perform important roles in its growth and production; nevertheless, little is known about the changes that occur in these communities under disease-stress conditions. The present study investigated the bacterial diversity and their metabolic profile in the rhizosphere of disease-resistant (JS-20-34) and disease-susceptible (JS-335) soybean (Glycine max (L.) Merr.) cultivars using 16S rRNA amplicon sequencing and community-level physiological profiling (CLPP). In disease-resistant soybean (AKADR) samples, the most dominating phyla were Actinobacteria (40%) followed by Chloroflexi (24%), Proteobacteria (20%), and Firmicutes (12%), while in the disease-susceptible (AKADS) sample, the most dominating phyla were Proteobacteria (35%) followed by Actinobacteria (27%) and Bacteroidetes (17%). Functional profiling of bacterial communities was done using the METAGENassist, and PICRUSt2 software, which shows that AKADR samples have more ammonifying, chitin degrading, nitrogen-fixing, and nitrite reducing bacteria compared to AKADS rhizosphere samples. The bacterial communities present in disease-resistant samples were significantly enriched with genes involved in nitrogen fixation, carbon fixation, ammonification, denitrification, and antibiotic production. Furthermore, the CLPP results show that carbohydrates and carboxylic acids were the most frequently utilized nutrients by the microbes. The principal component analysis (PCA) revealed that the AKADR soils had higher functional activity (strong association with the Shannon-Wiener index, richness index, and hydrocarbon consumption) than AKADS rhizospheric soils. Overall, our findings suggested that the rhizosphere of resistant varieties of soybean comprises of beneficial bacterial population over susceptible varieties.

Efficacy and safety of daily treatments for drug-susceptible pulmonary tuberculosis: a systematic review and network meta-analysis.

OBJECTIVES: To evaluate and update the evidence on the comparative efficacy and safety of antimicrobial drugs regimens for treating pulmonary drug-susceptible tuberculosis (DS-TB). METHODS: A systematic review was performed with searches in PubMed and Scopus (PROSPERO-CRD42019141463). We included randomised controlled trials comparing the effect of any antimicrobial regimen lasting at least 2 weeks. The outcomes of interest were culture conversion and incidence of adverse events. Bayesian network meta-analyses and surface under the cumulative ranking curve (SUCRA) analyses were performed. Results were reported as odds ratio with 95% credibility intervals. KEY FINDINGS: Fifteen studies were included the meta-analysis (n = 7560 patients). No regimen was statistically more effective than the WHO standard approach (rifampicin, isoniazid, ethambutol, and pyrazinamide). The use of rifapentine 450 mg instead of rifampicin in the standard regimen demonstrated to be statistically safer than all other options for serious adverse events (e.g. hepatotoxicity, arthralgia) (OR ranging from 0.0 [Crl 0.00-0.04] to 0.0 [0.00-0.97]; SUCRA probabilities of 10%). Therapies containing rifapentine (Rp1500HEZ, Rp900HEZ) and moxifloxacin (RMEZ, RHMZ) are effective regarding culture conversion, but statistical uncertainty on their safety profile exists. CONCLUSION: The WHO standard regimen remains an overall effective and safe alternative for DS-TB. For intensive phase treatments, drugs combinations with rifapentine and moxifloxacin seem to reduce treatment duration while maintaining efficacy.

Sensitivity theorems of a model of multiple imperfect vaccines for COVID-19.

In response to the ongoing pandemic of COVID-19, several companies across the world have proposed a wide variety of vaccines of different mechanisms of action. As a consequence, a new scenario of multiple imperfect vaccines against the SARS-CoV-2 arose. Mathematical modeling needs to consider this complex situation with different vaccines, some of them with two required doses. Using compartmental models we can simplify, simulate and most importantly, answer questions related to the development of the outbreak and the vaccination campaign. We present a model that addresses the current situation of COVID-19 and vaccination. Two important questions were considered in this paper: are more vaccines useful to reduce the spread of the coronavirus? How can we know if the vaccination campaign is sufficient? Two sensitivity criteria are helpful to answer these questions. The first criterion is the Multiple Vaccination Theorem, which indicates whether a vaccine is giving a positive or negative impact on the reproduction number. The second result (Insufficiency Theorem) provides a condition to answer the second question. Finally, we fitted the parameters with data and discussed the empirical results of six countries: Israel, Germany, the Czech Republic, Portugal, Italy, and Lithuania.

Haemonchus contortus infection induces a variable immune response in resistant and susceptible Pelibuey sheep.

The immune response and phenotypic characteristics of Pelibuey lambs were analysed after the induction of a Haemonchus contortus trickle infection. Male lambs (n = 29; 20 kg live weight) were infected with 100 H. contortus infective larvae per kg of live weight on day 3, 5 and 7 of the experiment. The number of eggs per gram (epg), seven haematological parameters and the immunoglobulin A (IgA) level were analysed for 56 experimental days. In addition, histopathological samples from the fundic abomasal region and the relative expression of 10 immune-related genes from 15 infected and three non-infected lambs were analysed at day 0 and 49 of the experiment. The epg count and some haematological parameters (leucocytes, red blood cells, haemoglobin and total protein) with statistically significant differences (P < 0.01) were used to identify nine resistant and 20 susceptible lambs (1166 ±â€¯1071 and 3171 ±â€¯1463 epg, respectively). Moreover, acute infiltration of immune cells and parasitic granuloma formation were observed in susceptible lambs; the resistant group had moderate inflammatory cell infiltration. With respect to relative gene expression, resistant lambs showed upregulation (P < 0.001) of 10 genes, from 2.2 to 15.99 fold. Moreover, there was a strong indirect correlation (P < 0.05) between the epg count and interleukin 5 (IL5) gene expression. By contrast, there was an average 0.34 fold downregulation in nine of the immune-related genes (P ≤ 0.05) in susceptible lambs (the only exception was Fc fragment of IgE receptor Ia [FCER1A] upregulation). In addition, there was a direct correlation (P ≤ 0.05) between the epg count and the expression of IL8, which encodes an inflammatory chemokine. In conclusion, this study showed differential IL5 and IL8 gene expression during haemonchosis in resistant and susceptible Pelibuey lambs, respectively, together with a variable immune response based on histopathological and haematological parameters.

Susceptible host availability modulates climate effects on dengue dynamics.

Experiments and models suggest that climate affects mosquito-borne disease transmission. However, disease transmission involves complex nonlinear interactions between climate and population dynamics, which makes detecting climate drivers at the population level challenging. By analysing incidence data, estimated susceptible population size, and climate data with methods based on nonlinear time series analysis (collectively referred to as empirical dynamic modelling), we identified drivers and their interactive effects on dengue dynamics in San Juan, Puerto Rico. Climatic forcing arose only when susceptible availability was high: temperature and rainfall had net positive and negative effects respectively. By capturing mechanistic, nonlinear and context-dependent effects of population susceptibility, temperature and rainfall on dengue transmission empirically, our model improves forecast skill over recent, state-of-the-art models for dengue incidence. Together, these results provide empirical evidence that the interdependence of host population susceptibility and climate drives dengue dynamics in a nonlinear and complex, yet predictable way.

Virulence-Associated Characteristics of Serotype 14 and Serogroup 9 Streptococcus pneumoniae Clones Circulating in Brazil: Association of Penicillin Non-susceptibility With Transparent Colony Phenotype Variants.

Streptococcus pneumoniae remains a major agent of invasive diseases, especially in children and the elderly. The presence of pneumococcal capsule, pneumococcal surface protein A (PspA), and pilus type 1 (PI-1) and the ability of colony phase variation are assumed to play important roles in the virulence potential of this microorganism. Differences in the capsular polysaccharide allow the characterization of more than 90 pneumococcal serotypes; among them, serotype 14 and serogroup 9 stand out due to their prevalence in the pre- pneumococcal conjugate vaccine era and frequent association with penicillin non-susceptibility. Here we investigated the distribution of PI-1 and pspA genes and colony phase variants among 315 S. pneumoniae isolates belonging to serotype 14 and serogroup 9, recovered over 20 years in Brazil, and correlated these characteristics with penicillin susceptibility and genotype as determined by multilocus sequence typing. All strains were shown to carry pspA genes, with those of family 2 (pspA2) being the most common, and nearly half of the strains harbored P1-1 genes. The pspA gene family and the presence of PI-1 genes were conserved features among strains belonging to a given clone. A trend for increasing the occurrence of pspA2 and PI-1 genes over the period of investigation was observed, and it coincided with the dissemination of CC156 (Spain9V -3) clone in Brazil, suggesting a role for these virulence attributes in the establishment and the persistence of this successful clone. Opaque variant was the colony phenotype most frequently observed, regardless of clonal type. On the other hand, the transparent variant was more commonly associated with penicillin-non-susceptible pneumococci and with strains presenting evidence of recombination events involving the genes coding for polysaccharide capsule and PspA, suggesting that pneumococcal transparent variants may present a higher ability to acquire exogenous DNA. The results bring to light new information about the virulence potentials of serotype 14 and serogroup 9 S. pneumoniae isolates representing the major clones that have been associated with the emergence and the dissemination of antimicrobial resistance in our setting since the late 1980s.

Association of TNF rs668920841 and INRA111 polymorphisms with caprine brucellosis: A case-control study of candidate genes involved in innate immunity.

Caprine brucellosis is an infectious, contagious zoonotic disease caused by Brucella melitensis. Multiple factors, including host genetics, can influence the outcome of the exposure to Brucella; and it is expected that genetic variants that affect the host innate immune response could have a key role in Brucella infection and pathogenesis. In this study, we evaluated if polymorphisms in innate immunity-related genes are associated with results of Brucella infection in goats. Nine polymorphisms within interferon gamma (IFNG), tumor necrosis factor (TNF), MyD88 innate immune signal transduction adaptor (MYD88), interleukin 10 (IL10) and IL-10 receptor subunit alpha (IL10RA) genes and two molecular markers (BMS2753 and INRA111) were resolved by PCR-capillary electrophoresis in samples from 81 seronegative and 61 seropositive goats for brucellosis. A heterozygous genotype at INRA111, a microsatellite near the VRK serine/threonine kinase 2 (VRK2) gene, was associated with absence of Brucella-specific antibodies in goats naturally exposed to the pathogen (P = .004). Conversely, variants in the TNF gene (rs668920841) and near the IFN gamma receptor 1 (IFNGR1) gene (microsatellite BMS2753) were significantly associated with presence of Brucella-specific antibodies at allelic (P = .042 and P = .046) and genotypic level (P = .012 and P = .041, respectively). Moreover, an in silico analysis predicted a functional role of the insertion-deletion polymorphism rs668920841 on the transcriptional regulation of the caprine TNF gene. Altogether, these results contribute to the identification of genetic factors that have a putative effect on the resistance / susceptibility phenotype of goats to Brucella infection.

Propuesta de un modelo SYIR modificado para predecir la cinemática de la epidemia por COVID-19 / Proposal for a modified SYIR model to predict the kinematics of the COVID-19 epidemic

In late 2019, an infection in humans by the SARS-CoV-2 virus was detected for the first time in Wuhan, China. By February, several countries had sustained viral circulation. On March 11, the World Health Organization (WHO) declared a global pandemic. Initially, one of the main concerns regarding the spread of this pathogen was the possible lack of capacity of health systems to absorb the demand for resources in a pandemic situation. At the local level, on March 19 a measure of "social, preventive and mandatory isolation" was established, from March 20 to March 31, 2020, in order to protect public health, which was later extended until March 26 April through DNU 335/2020. MEDICUS is a private medicine company with representation throughout Argentina for 48 years. 85% of its affiliates reside in the Metropolitan Area of Buenos Aires (AMBA), Argentina. The objective of this study is to propose a modified SYIR (Susceptible-Contagious-Infective-Recovered) model, with the purpose of generating a monitoring tool that can anticipate the behavior of the COVID-19 pandemic in the AMBA population of a company prepayment, and the consequences of the measures adopted by the health authorities and their compliance over time. In the case of MEDICUS, for the optimistic scenario, a start of the peak of cases is expected in the first week of June and an end in late November, with a peak in early September; the pessimistic scenario begins the peak in mid-April, reaches its maximum in late May and ends in mid-June. It presents a much larger number of cases, more concentrated in time. The moderate scenario is an intermediate of both. The COVID-19 pandemic is a huge challenge for all health systems in the world, not just for Argentina. In our study, we forecast three possible scenarios for the behavior of the pandemic (optimistic, moderate and pessimistic) that will depend on the characteristics, adherence and persistence of the isolation measures in our country. Given the current dynamics and compliance with these measures, we estimate it possible that the real measure is somewhere between the optimistic and moderate scenarios.

A fines del año 2019, se detectó por primera vez en Wuhan, China, una infección en seres humanos por el virus SARS-CoV-2. Para febrero, varios países registraban circulación viral sostenida. El 11 de marzo la Organización Mundial de la Salud (OMS) declaró la pandemia mundial. Inicialmente, una de las principales preocupaciones ante la expansión de este patógeno fue la posible falta de capacidad de los sistemas sanitarios para absorber la demanda de recursos ante una situación de pandemia. En el ámbito local, el 19 de marzo se estableció una medida de "aislamiento social, preventivo y obligatorio", desde el 20 hasta el 31 de marzo de 2020, con el fin de proteger la salud pública, que luego se extendió hasta el 26 de abril mediante el DNU 335/2020. MEDICUS es una empresa de medicina prepaga con representación en toda la Argentina desde hace 48 años. El 85% de sus afiliados reside en el Área Metropolitana de Buenos Aires (AMBA). El objetivo de este trabajo es proponer un modelo SYIR (Susceptible-Contagiado-Infectante- Recuperado) modificado, con el propósito de generar una herramienta de seguimiento que pueda anticipar el comportamiento de la pandemia de COVID-19 en la población del AMBA de una empresa prepaga, y las consecuencias de las medidas adoptadas por las autoridades sanitarias y su cumplimiento a través del tiempo. En el caso de MEDICUS, para el escenario optimista se espera un inicio del pico de casos en la primera semana de junio y una finalización a fines de noviembre, con un máximo a comienzos de septiembre; el escenario pesimista inicia el pico a mediados de abril, llega a su máximo a fines de mayo y lo termina a mediados de junio. Presenta un número mucho mayor de casos, más concentrado en el tiempo. El escenario moderado es un intermedio de ambos. La pandemia de COVID-19 es un enorme desafío para todos los sistemas de salud del mundo, no solo para el argentino. En nuestro estudio, pronosticamos tres escenarios posibles de comportamiento de la pandemia (optimista, moderado y pesimista) que dependerán de las características, la adhesión y la persistencia de las medidas de aislamiento en nuestro país. Por la dinámica actual y el cumplimiento de estas medidas, estimamos posible que la real medida se sitúe en algún punto entre el escenario optimista y el moderado

First report of a catheter-related bloodstream infection by Candida haemulonii in a children's hospital in Mexico City.

BACKGROUND: Candida haemulonii is an emergent, multi-resistant opportunistic pathogenic yeast that like Candida auris, can be misidentified when conventional diagnostic methods are used. Timely molecular identification using DNA sequence analysis variation in the internal transcriber spacer region, ITS1-ITS4 and the 28S ribosomal DNA gene (28S rDNA), and in vitro antifungal susceptibility assessment can lead to rapid therapeutic success. CASE REPORT: A case of Candida haemulonii candidiasis suffered by a male paediatric patient attended at Federico Gómez Children's Hospital of México City in September 2016 is reported. The isolate was yielded from peripheral blood and central catheter blood specimens. From in vitro antifungal susceptibility data, caspofungin was administered to the patient, who showed clear improvements at the end of antimicrobial administration, and the removal of the central venous catheter. Using a molecular phylogenetic approach, we identified the clinical isolate as C. haemulonii. The clinical isolate has been named as Candida haemulonii ENCB-87 from now on. C. haemulonii ENCB-87 grew well between the temperatures, 28 °C and 35 °C but not at 37 °C in YPD culture medium. The clinical isolate was susceptible to caspofungin, which resulted in therapeutic success for the patient. CONCLUSIONS: C. haemulonii is an emergent, opportunistic pathogen, closely related to C. auris, therefore, the timely and accurate identification and antifungal susceptibility assessments are paramount in generating a robust epidemiology of this emerging Candida species.