DNA Barcoding Reveals Generalization and Host Overlap in Hummingbird Flower Mites: Implications for the Mating Rendezvous Hypothesis.

AbstractHummingbird flower mites are assumed to monopolize single host plant species owing to sexual selection for unique mating rendezvous sites. We tested the main assumption of the mating rendezvous hypothesis-extreme host specialization-by reconstructing interactions among tropical hummingbird flower mites and their host plants using DNA barcoding and taxonomic identifications. We collected 10,654 mites from 489 flowers. We extracted DNA from 1,928 mite specimens and amplified the cytochrome c oxidase I (CO1) DNA barcode. We analyzed the network structure to assess the degree of generalization or specialization of mites to their host plants. We recorded 18 species of hummingbird flower mites from three genera (Proctolaelaps, Rhinoseius, and Tropicoseius) interacting with 14 species of plants. We found that generalist mites are common, and congeneric mite species often share host plants. Our results challenge the assumption of strict specialization that supports this system as an example of mating rendezvous evolution.

Demographic Attritions, Elevational Refugia, and the Resilience of Insect Populations to Projected Global Warming.

AbstractTropical mountains might protect species from global warming by facilitating biotic migrations upslope. Current predictions of tropical biotic responses to global warming are based on correlations between species elevational distributions and temperatures. Because biotic attritions, range shifts, and mountaintop extinctions result from complex demographic processes, predictive models must be based on mechanistic associations between temperature and fitness. Our study combines long-term temperature records with experimental demography to determine the contribution of local adaptation to organismal resilience in a warming world. On the Barva volcano in Costa Rica, Cephaloleia belti (Coleoptera: Chrysomelidae) displays high-elevation (960-2,100 m asl) and low-elevation (50-960 m asl) mitochondrial haplotypes. We reared haplotype cohorts at temperatures prevalent along the elevational gradient (i.e., 10°-30°C). Based on ambient temperatures recorded every half hour for 4 years, we projected average instantaneous population growth rates ([Formula: see text]) at current and future temperatures (i.e., +1° to 6°C) for each beetle haplotype. Haplotypes are adapted to local temperatures, but with a temperature increase beyond 2°C, both haplotypes will face lower-elevation demographic attritions and extinctions. Upper distribution limits serve as potential elevational refugia from global warming. This study shows how species resilience to global warming emerges from complex fitness responses of locally adapted phenotypes facing novel environments.

Model Systems in Ecology, Evolution, and Behavior: A Call for Diversity in Our Model Systems and Discipline.

AbstractEcologists and evolutionary biologists are fascinated by life's variation but also seek to understand phenomena and mechanisms that apply broadly across taxa. Model systems can help us extract generalities from amid all the wondrous diversity, but only if we choose and develop them carefully, use them wisely, and have a range of model systems from which to choose. In this introduction to the Special Feature on Model Systems in Ecology, Evolution, and Behavior (EEB), we begin by grappling with the question, What is a model system? We then explore where our model systems come from, in terms of the skills and other attributes required to develop them and the historical biases that influence traditional model systems in EEB. We emphasize the importance of communities of scientists in the success of model systems-narrow scientific communities can restrict the model organisms themselves. We also consider how our discipline was built around one type of "model scientist"-a history still reflected in the field. This lack of diversity in EEB is unjust and also narrows the field's perspective, including by restricting the questions asked and talents used to answer them. Increasing diversity, equity, and inclusion will require acting at many levels, including structural changes. Diversity in EEB, in both model systems and the scientists who use them, strengthens our discipline.

Positive genetic covariance and limited thermal tolerance constrain tropical insect responses to global warming.

Tropical ectotherms are particularly vulnerable to global warming because their physiologies are assumed to be adapted to narrow temperature ranges. This study explores three mechanisms potentially constraining thermal adaptation to global warming in tropical insects: (a) Trade-offs in genotypic performance at different temperatures (the jack-of-all-trades hypothesis), (b) positive genetic covariance in performance, with some genotypes performing better than others at viable temperatures (the 'winner' and 'loser' genotypes hypothesis), or (c) limited genetic variation as the potential result of relaxed selection and the loss of genes associated with responses to extreme temperatures (the gene decay hypothesis). We estimated changes in growth and survival rates at multiple temperatures for three tropical rain forest insect herbivores (Cephaloleia rolled-leaf beetles, Chrysomelidae). We reared 2,746 individuals in a full sibling experimental design, at temperatures known to be experienced by this genus of beetles in nature (i.e. 10-35°C). Significant genetic covariance was positive for 16 traits, supporting the 'winner' and 'loser' genotypes hypothesis. Only two traits displayed negative cross-temperature performance correlations. We detected a substantial contribution of genetic variance in traits associated with size and mass (0%-44%), but low heritability in plastic traits such as development time (0%-6%) or survival (0%-4%). Lowland insect populations will most likely decline if current temperatures increase between 2 and 5°C. It is concerning that local adaption is already lagging behind current temperatures. The consequences of maintaining the current global warming trajectory would be devastating for tropical insects. However, if humans can limit or slow warming, many tropical ectotherms might persist in their current locations and potentially adapt to warmer temperatures.

Standardized ethograms and a device for assessing amphibian thermal responses in a warming world.

Most predictions of how populations and species of ectotherms will respond to global warming are based on estimates of the temperature at which organisms lose motor control (i.e., CTmax - the Critical Thermal Maximum). Here, we describe a non-lethal protocol and ethograms to estimate the relative tolerance of amphibians to increasing temperatures. These methods-suitable for field or laboratory conditions-are replicable, inexpensive and applicable to both post-metamorphic stages and organisms with direct development. We illustrate the use of this standardized protocol for four amphibians from a tropical cloud forest in Veracruz, Mexico with contrasting life histories: a lungless salamander (Aquiloeurycea cafetalera: Plethodontidae), a leaf-litter frog (Craugastor rhodopis: Craugastoridae), a semiaquatic frog (Lithobates berlandieri: Ranidae), and a tree frog (Rheohyla miotympanum: Hylidae). We identified four behavioral responses preceding CTmax for all amphibians included in this study: 1) Optimal Activity Range, 2) Supra-optimal Activity Range, 3) Heat Stress Range, and 4) Involuntary Movements Range. Additionally, we identified a fifth parameter associated with resilience to heat shock: 5) Recovery Stage after reaching CTmax. We conclude that the behavioral responses preceding the Critical Thermal Maximum are as informative as CTmax. Using behavioral responses to estimate thermal tolerance has the additional advantage of reducing the risk of injury or death of amphibians during physiological experiments.

Recurrent Papillary Thyroid Carcinoma to the Cervical Lymph Nodes: Outcomes of Compartment-Oriented Lymph Node Resection.

INTRODUCTION: Recurrence of papillary thyroid carcinoma after initial treatment is challenging. Surgical reintervention is recommended, but cure after surgery in uncertain and surgical morbidity may be high. This study evaluates the effect of compartment-oriented lymph node dissection (LND) on clinical and biochemical cure rate as well as the related complications. PATIENTS AND METHODS: All patients who underwent LND for recurrent papillary thyroid carcinoma between 2000 and 2015 were included. Demography, the extent of the initial surgery, usage of 131I, the pattern of recurrence, diagnosis, details of the surgical reintervention, histological findings, surgical morbidity, and clinical and biochemical outcomes were analyzed. RESULTS: There were 11 (12.7%) males and 75 (87.2%) females with a mean age of 42.8 ± 14.6 years. Seventy-seven patients had undergone total thyroidectomy and in 67 (77.9%) some type of LN resection. In 76 (88.3%), 131I was administered after the initial surgery. We localized suspicious lymph nodes by US in all patients, and metastases were documented before surgery by FNA in 63. Seven (8.13%) patients underwent central LND, 63 (73.2%) lateral LND and 16 (18.6%) both, central and lateral LND. Major complications occurred in 6 patients (6.9%). Sixty-two (72.0%) patients received 131I after surgery. A second surgical re-exploration was performed in 30 (34.8%) patients, and 7 patients required 3 or more additional LND. In a mean follow-up of 59.4 ± 39 months, 51 (59.3%) patients are clinically, radiologically and biochemically free of disease. CONCLUSIONS: In this series, compartment-oriented lymph node resection of recurrent papillary thyroid carcinoma leads to a final clinical and biochemical disease-free status of 59.3% with 6.9% of major complications.

Limited tolerance by insects to high temperatures across tropical elevational gradients and the implications of global warming for extinction.

The critical thermal maximum (CTmax), the temperature at which motor control is lost in animals, has the potential to determine if species will tolerate global warming. For insects, tolerance to high temperatures decreases with latitude, suggesting that similar patterns may exist along elevational gradients as well. This study explored how CTmax varies among species and populations of a group of diverse tropical insect herbivores, the rolled-leaf beetles, across both broad and narrow elevational gradients. Data from 6,948 field observations and 8,700 museum specimens were used to map the elevational distributions of rolled-leaf beetles on two mountains in Costa Rica. CTmax was determined for 1,252 individual beetles representing all populations across the gradients. Initial morphological identifications suggested a total of 26 species with populations at different elevations displaying contrasting upper thermal limits. However, compared with morphological identifications, DNA barcodes (cytochrome oxidase I) revealed significant cryptic species diversity. DNA barcodes identified 42 species and haplotypes across 11 species complexes. These 42 species displayed much narrower elevational distributions and values of CTmax than the 26 morphologically defined species. In general, species found at middle elevations and on mountaintops are less tolerant to high temperatures than species restricted to lowland habitats. Species with broad elevational distributions display high CTmax throughout their ranges. We found no significant phylogenetic signal in CTmax, geography, or elevational range. The narrow variance in CTmax values for most rolled-leaf beetles, especially high-elevation species, suggests that the risk of extinction of insects may be substantial under some projected rates of global warming.

Low quality diet and challenging temperatures affect vital rates, but not thermal tolerance in a tropical insect expanding its diet to an exotic plant.

Determining responses of organisms to changing temperatures is a research priority, as global warming threatens populations and ecosystems worldwide. Upper thermal limits are frequently measured as the critical thermal maximum (CTmax), a quick bioassay where organisms are exposed to increasing temperatures until individuals are not able to perform basic motor activities such as walking or flying. A more informative approach to understand organism responses to global warming is to evaluate how vital rates, such as growth or survival, change with temperatures. The main objectives of this study are: (1) to determine if factors affecting insect vital rates such as diet quality, developmental temperatures or acclimation also affect CTmax and (2) to determine if vital rates of different life stages (i.e., insect larvae or adults) display different responses to temperature changes. If different life stages have particular thermal requirements, this may indicate different susceptibility to global warming. This study focuses on Cephaloleia belti (Coleoptera: Chrysomelidae), a tropical insect currently expanding its diet to an exotic host plant. We determined how high and low-quality diets (i.e., native vs novel host), as well as exposure temperatures affect CTmax of adult beetles. We also estimated larval and adult survival when feeding on high and low quality host plants, when exposed to temperatures typical of the elevational distribution of this species, or when exposed to projected temperatures in 100 years. We did not detect an effect of diet quality or acclimation on CTmax. However, larvae and adults had different thermal requirements. CTmax is not affected by previous diet or acclimation as an adult. We propose that to understand processes involved in the adaptation and persistence of ectotherm populations in a warming world, studies must explore responses beyond CTmax, and focus on the response of vital rates to changing temperatures.

Experimental assemblage of novel plant-herbivore interactions: ecological host shifts after 40 million years of isolation.

Geographic isolation is the first step in insect herbivore diet specialization. Such specialization is postulated to increase insect fitness, but may simultaneously reduce insect ability to colonize novel hosts. During the Paleocene-Eocene, plants from the order Zingiberales became isolated either in the Paleotropics or in the Neotropics. During the Cretaceous, rolled-leaf beetles diversified in the Neotropics concurrently with Neotropical Zingiberales. Using a community of Costa Rican rolled-leaf beetles and their Zingiberales host plants as study system, we explored if previous geographic isolation precludes insects to expand their diets to exotic hosts. We recorded interactions between rolled-leaf beetles and native Zingiberales by combining DNA barcodes and field records for 7450 beetles feeding on 3202 host plants. To determine phylogenetic patterns of diet expansions, we set 20 field plots including five exotic Zingiberales, recording beetles feeding on these exotic hosts. In the laboratory, using both native and exotic host plants, we reared a subset of insect species that had expanded their diets to the exotic plants. The original plant-herbivore community comprised 24 beetle species feeding on 35 native hosts, representing 103 plant-herbivore interactions. After exotic host plant introduction, 20% of the beetle species expanded their diets to exotic Zingiberales. Insects only established on exotic hosts that belong to the same plant family as their native hosts. Laboratory experiments show that beetles are able to complete development on these novel hosts. In conclusion, rolled-leaf beetles are pre-adapted to expand their diets to novel host plants even after millions of years of geographic isolation.

Ertapenem resistance in 2 tertiary-care hospitals: Microbiology, epidemiology, and risk factors. / Resistencia a ertapenem en 2 instituciones hospitalarias de alto nivel de complejidad: microbiología, epidemiología y factores de riesgo.

INTRODUCTION: Carbapenems resistance is a growing phenomenon and a threat to public health because of the reduced therapeutic options for resistant infections. METHODS: A retrospective case-control study was conducted in 2 tertiary-care hospitals in Medellín, Colombia. Fifty patients infected with ertapenem-resistant enterobacteriaceae were compared with a control group consisting of 100 patients with infections caused by ertapenem susceptible enterobacteriaceae. A multivariate logistic regression model was used to identify factors that best explain ertapenem-resistant enterobacteriaceae infections. RESULTS: The factors associated with ertapenem-resistant enterobacteriaceae infections were prior exposure to carbapenems (adjusted OR 3.43; 95% IC 1.08-10.87) and prior exposure to cefepime (adjusted OR 6.46; 95% IC 1.08-38.38). CONCLUSION: Prior exposure to antibiotics is the factor that best explains the ertapenem-resistant enterobacteriaceae infection in this population, highlighting the importance of antimicrobial stewardship programs in hospitals.

Similar frequencies of Pseudomonas aeruginosa isolates producing KPC and VIM carbapenemases in diverse genetic clones at tertiary-care hospitals in Medellín, Colombia.

Carbapenem-resistant Pseudomonas aeruginosa has become a serious health threat worldwide due to the limited options available for its treatment. Understanding its epidemiology contributes to the control of antibiotic resistance. The aim of this study was to describe the clinical and molecular characteristics of infections caused by carbapenem-resistant P. aeruginosa isolates in five tertiary-care hospitals in Medellín, Colombia. A cross-sectional study was conducted in five tertiary-care hospitals from June 2012 to March 2014. All hospitalized patients infected by carbapenem-resistant P. aeruginosa were included. Clinical information was obtained from medical records. Molecular analyses included PCR for detection of bla(VIM), bla(IMP), bla(NDM), bla(OXA-48), and bla(KPC) genes plus pulsed-field gel electrophoresis (PFGE) and multilocus sequence typing (MLST) for molecular typing. A total of 235 patients were enrolled: 91.1% of them were adults (n = 214), 88.1% (n = 207) had prior antibiotic use, and 14.9% (n = 35) had urinary tract infections. The bla(VIM-2) and bla(KPC-2) genes were detected in 13.6% (n = 32) and 11.5% (n = 27), respectively, of all isolates. Two isolates harbored both genes simultaneously. For KPC-producing isolates, PFGE revealed closely related strains within each hospital, and sequence types (STs) ST362 and ST235 and two new STs were found by MLST. With PFGE, VIM-producing isolates appeared highly diverse, and MLST revealed ST111 in four hospitals and five new STs. These results show that KPC-producing P. aeruginosa is currently disseminating rapidly and occurring at a frequency similar to that of VIM-producing P. aeruginosa isolates (approximately 1:1 ratio) in Medellín, Colombia. Diverse genetic backgrounds among resistant strains suggest an excessive antibiotic pressure resulting in the selection of resistant strains.

Growth-defense trade-offs promote habitat isolation between recently-diverged species.

Trade-offs are crucial for species divergence and reproductive isolation. Trade-offs between investment in growth versus defense against herbivores are implicated in tropical forest diversity. Empirically exploring the role of growth-defense trade-offs in closely related species' reproductive isolation can clarify the eco-evolutionary dynamics through which growth-defense trade-offs contribute to diversity. Costus villosissimus and C. allenii are recently diverged, interfertile, and partially sympatric neotropical understory plant species primarily isolated by divergent habitat adaptation. This divergent adaptation involves differences in growth rate, which may constrain investment in defense. Here, we investigate growth-defense trade-offs and how they relate to the divergent habitat adaptation that isolates these species. We characterize leaf toughness and chemistry, evaluate the feeding preferences of primary beetle herbivores in controlled trials and field-based experiments, and investigate natural herbivory patterns. We find clear trade-offs between growth and defense: slower-growing C. allenii has tougher leaves and higher defensive chemical concentrations than faster-growing C. villosissimus. Costus villosissimus has rapid growth-based drought avoidance, enabling growth in drier habitats with few specialist herbivores. Therefore, growth-defense trade-offs mediate synergistic biotic and abiotic selection, causing the divergent habitat adaptation that prevents most interspecific mating between C. villosissimus and C. allenii. Our findings advance understanding of ecological speciation by highlighting the interplay of biotic and abiotic selection that dictates the outcome of trade-offs.

The subjective perception of the happiness of older adult residents in Colombia.

Introduction: Happiness is understood as the perception of subjective well-being, it can be a quality, a result, or a state characterized by well-being or satisfaction that every person wants to achieve. In older adults, this satisfaction is a sum of lifelong achievements and triumphs; However, some factors influence this ideal. Objective: Analyze demographic, family, social, personal, and health factors associated with the subjective perception of happiness in older adults, using data from a study conducted in five cities in Colombia, in order to make a theoretical contribution in the search for improvement of their physical, mental and social health. Materials and methods: A quantitative, cross-sectional, analytical study was carried out, using primary source information, obtained with 2,506 surveys from voluntary participants aged 60 and over, who had no cognitive impairment, and who reside in urban areas but not in long-term centers. The variable happiness (classified as high or moderate/low) was used for: (1) A univariate explorative characterization of older adult, (2) a bivariate estimation of the relationships with the factors studied, and (3) a multivariate construction of profiles through multiple correspondences. Results: 67.2% reported high happiness levels, with differences by city: Bucaramanga (81.6%), Pereira (74.7%), Santa Marta (67.4), Medellín (64%), and Pereira (48.7%). Happiness was explained by the absence of risk of depression and little hopelessness, strengthened psychological well-being, a perception of high quality of life, and living in a functional family. Conclusion: This study provided an overview of possible factors that can be enhanced and strengthened with public policies (structural determinant), community empowerment, family strengthening (intermediate determinant), and educational programs (proximal determinant). These aspects are included in the essential functions of public health, in favor of mental and social health in older adults.

Jack of all trades masters novel host plants: positive genetic correlations in specialist and generalist insect herbivores expanding their diets to novel hosts.

One explanation for the widespread host specialization of insect herbivores is the 'Jack of all trades-master of none' principle, which states that genotypes with high performance on one host will perform poorly on other hosts. This principle predicts that cross-host correlation in performance of genotypes will be negative. In this study, we experimentally explored cross-host correlations and performance among families in four species (two generalist and two specialist) of leaf beetles (Cephaloleia spp.) that are currently expanding their diets from native to exotic plants. All four species displayed similar responses in body size, developmental rates and mortality rates to experimentally controlled diets. When raised on novel hosts, body size of larvae, pupae and adults were reduced. Development times were longer, and larval mortality was higher on novel hosts. Genotype × host-plant interactions were not detected for most traits. All significant cross-host correlations were positive. These results indicate very different ecological and evolutionary dynamics than those predicted by the 'Jack of all trades-master of none' principle.

Changes in Antimicrobial Resistance and Etiology of Blood Culture Isolates: Results of a Decade (2010-2019) of Surveillance in a Northern Region of Colombia.

Background: Bloodstream infections (BSI) are important causes of morbidity and mortality worldwide. Antimicrobial surveillance is essential for identifying emerging resistance and generating empirical treatment guides, the purpose of this study is to analyze trends in antimicrobial susceptibility of BSI from 2010 to 2019 in healthcare institutions from Medellin and nearby towns in Colombia. Methods: A Whonet database was analyzed from the GERMEN antimicrobial surveillance network; frequency and antibiotic susceptibility trends were calculated on more frequent microorganisms using Mann Kendall and Sen's Slope Estimator Test. Results: 61,299 isolates were included; the three microorganisms more frequent showed a significant increasing trend through time E. coli (Sen's Slope estimator = 0.7 p = <0.01) S. aureus (Sen's Slope estimator = 0.60 p = <0.01) and K. pneumonia (Sen's Slope estimator = 0.30 p = <0.01). E. coli showed a significant increase trend in cefepime and ceftazidime resistance, while K. pneumoniae showed a significant increase in resistance to cefepime, ciprofloxacin, and gentamicin. P. aeruginosa increases its susceptibility to all analyzed antibiotics and S. aureus to oxacillin. No increasing trend was observed for carbapenem resistance. Conclusion: An upward trends was observed in more frequent microorganisms and resistance to third and fourth-generation cephalosporins for E. coli and K pneumoniae; in contrast, not increasing trends in antibiotic resistance was observed for P. aeruginosa and S. aureus. The essential role of AMR-surveillance programs is to point out and identify these trends, which should improve antibiotic resistance control.

Experimental demography and the vital rates of generalist and specialist insect herbivores on native and novel host plants.

1. Colonization success of species when confronted with novel environments is of interest in ecological, evolutionary and conservation contexts. Such events may represent the first step for ecological diversification. They also play an important role in adaptive divergence and speciation. 2. A species that is able to do well across a range of environments has a higher plasticity than one whose success is restricted to a single or few environments. The breadth of environments in which a species can succeed is ultimately determined by the full pattern of its vital rates in each environment. 3. Examples of organisms colonizing novel environments are insect herbivores expanding their diets to novel host plants. One expectation for insect herbivores is that species with specialized diets may display less plasticity when faced with novel hosts than generalist species. 4. We examine this hypothesis for two generalist and two specialist neotropical beetles (genus Cephaloleia: Chrysomelidae) currently expanding their diets from native to novel plants of the order Zingiberales. Using an experimental approach, we estimated changes in vital rates, life-history traits and lifetime fitness for each beetle species when feeding on native or novel host plants. 5. We did not find evidence supporting more plasticity for generalists than for specialists. Instead, we found similar patterns of survival and fecundity for all herbivores. Larvae survived worse on novel hosts; adults survived at least as well or better, but reproduced less on the novel host than on natives. 6. Some of the novel host plants represent challenging environments where population growth was negative. However, in four novel plant-herbivore interactions, instantaneous population growth rates were positive. 7. Positive instantaneous population growth rates during initial colonization of novel host plants suggest that both generalist and specialist Cephaloleia beetles may be pre-adapted to feed on some novel hosts. This plasticity in host use is a key factor for successful colonization of novel hosts. Future success or failure in the colonization of these novel hosts will depend on the demographic rates described in this research, natural selection and the evolutionary responses of life-history traits in novel environments.

Effect of Chemical Pollution and Parasitism on Heat Tolerance in Dung Beetles (Coleoptera: Scarabaeinae).

Ecosystem services provided by insects are threatened by recent increasing global temperatures, particularly in the tropics, where insects live close to their thermal limits. Given that tolerance to high temperatures depends on individual metabolism and physiological stress response, it may also be sensitive to other stressors that are common in natural and human-modified environments, such as pollution and parasite pressure. The effects of multiple stressors could be synergistic and can be particularly relevant in insects that provide highly valuable ecosystem services, such as dung beetles in cattle pastures. Here we measured heat tolerance (critical thermal maximum, CTmax) in dung beetles exposed to ivermectin, a toxic parasiticide excreted in cattle dung, with known negative effects on coprophagous fauna, and in beetles exposed to an immune challenge. We also exposed a group of beetles to a combination of both ivermectin and immune challenge to test for potential synergistic effects of both stressors. Contrary to our predictions, CTmax did not change with ivermectin exposure, but increased in immune-challenged beetles. As found in other insects, CTmax was higher in larger beetles, highlighting the importance of body size on thermal tolerance in ectotherms. We discuss potential mechanisms responsible of increased heat tolerance in immune-challenged beetles and highlight the importance of natural and human-induced environmental pressures that now interact with global warming and threaten ecosystem services provided by wild animals.

Comparative study of Candida spp. isolates: Identification and echinocandin susceptibility in isolates obtained from blood cultures in 15 hospitals in Medellín, Colombia.

OBJECTIVES: Invasive candidiasis has a high impact on morbidity and mortality in hospitalised patients. Accurate and timely methods for identification of Candida spp. and determination of echinocandin susceptibility have become a priority for clinical microbiology laboratories. METHODS: This study was performed to compare matrix-assisted laser desorption/ionisation time-of-flight mass spectrometry (MALDI-TOF/MS) identification with sequencing of the D1/D2 region of the rRNA gene complex 28 subunit in 147 Candida spp. isolates obtained from patients with candidaemia. Antimicrobial susceptibility testing was performed by broth microdilution (BMD) and Etest. Sequencing of the FKS1 and FKS2 genes was performed. RESULTS: The most common species isolated were Candida albicans (40.8%), followed by Candida parapsilosis (23.1%) and Candida tropicalis (17.0%). Overall agreement between the results of identification by MALDI-TOF/MS and molecular identification was 99.3%. Anidulafungin and caspofungin susceptibility by the BMD method was 98.0% and 88.4%, respectively. Susceptibility to anidulafungin and caspofungin by Etest was 93.9% and 98.6%, respectively. Categorical agreement between Etest and BMD was 91.8% for anidulafungin and 89.8% for caspofungin, with lower agreements in C. parapsilosis for anidulafungin (76.5%) and C. glabrata for caspofungin (40.0%). No mutations related to resistance were found in the FKS genes, although 54 isolates presented synonymous polymorphisms in the hotspots sequenced. CONCLUSIONS: MALDI-TOF/MS is a good alternative for routine identification of Candida spp. isolates. DNA sequencing of the FKS genes suggested that the isolates analysed were susceptible to echinocandins; alternatively, unknown resistance mechanisms or limitations related to antifungal susceptibility tests may explain the resistance found in a few isolates.

[Comparison between two methods to measure herbivory. Is herbivory in the neotropics more severe than we thought?]. / Comparación de dos métodos para medir herbivoría. Es la herbivoría en el neotrópico mayor de lo que creemos?

The quantity of plant tissue consumed by herbivores can be recorded 1) by measuring herbivory in previously marked leaves or 2) by performing punctual measures. i.e. selecting leaves at random to measure the tissue absent in each leaf Punctual measurements are frequently used because they are a faster method to estimate herbivory. However, punctual measures do not include totally consumed leaves. therefore they underestimate the actual herbivory rates. In three species of understory shrubs (Palicourea sp. P. angustifolia and P. oralis: Rubiaccae) herbivory was measured using punctual measures and marking young leaves in order to determine the degree of herbivory underestimation by punctual measurements. Punctual measurements underestimated herbivory up to three times in the species with a high number of totally consumed leaves. In the species with a lower number of totally consumed leaves, herbivory rates recorded using both methods were similar. These results suggest that herbivory in neotropical forests could be more severe than what is currently suggested.