Etiology and the challenge of diagnostic testing of community-acquired pneumonia in children and adolescents.

BACKGROUND: Pneumonia is the leading cause of mortality in pediatric population. The etiology of pneumonia in this population is variable and changes according to age and disease severity and where the study is conducted. Our aim was to determine the etiology of community-acquired pneumonia (CAP) in children aged 1 month to 17 years admitted to 13 Colombian hospitals. METHODS: Prospective cohort study. Hospitalized children with radiologically confirmed CAP and ≤ 15 days of symptoms were included and followed together with a control group. Induced sputum (IS) was submitted for stains and cultures for pyogenic bacteria and Mycobacterium tuberculosis, and multiplex PCR (mPCR) for bacteria and viruses; urinary antigens for pneumococcus and Legionella pneumophila; nasopharyngeal swabs for viruses, and paired serology for atypical bacteria and viruses. Additional cultures were taken at the discretion of primary care pediatricians. RESULTS: Among 525 children with CAP, 71.6% had non-severe pneumonia; 24.8% severe and 3.6% very severe pneumonia, and no fatal cases. At least one microorganism was identified in 84% of children and 61% were of mixed etiology; 72% had at least one respiratory virus, 28% pyogenic bacteria and 21% atypical bacteria. Respiratory syncytial virus, Parainfluenza, Rhinovirus, Influenza, Mycoplasma pneumoniae, Adenovirus and Streptococcus pneumoniae were the most common etiologies of CAP. Respiratory syncytial virus was more frequent in children under 2 years and in severe pneumonia. Tuberculosis was diagnosed in 2.3% of children. IS was the most useful specimen to identify the etiology (33.6%), and blood cultures were positive in 3.6%. The concordance between all available diagnostic tests was low. A high percentage of healthy children were colonized by S. pneumoniae and Haemophilus influenzae, or were infected by Parainfluenza, Rhinovirus, Influenza and Adenovirus. CONCLUSIONS: Respiratory viruses are the most frequent etiology of CAP in children and adolescents, in particular in those under 5 years. This study shows the challenges in making an etiologic diagnosis of CAP in pediatric population because of the poor concordance between tests and the high percentage of multiple microorganisms in healthy children. IS is useful for CAP diagnosis in pediatric population.

Heat- and shear-reversible networks in food: A review.

While nature behaves like an irreversible network with respect to entropy and time, certain systems in nature exist that are, to some extent, reversible. The property of reversibility imparts unique benefits to systems that possess them, making them suitable for designing self-healing, stimuli-responsive, and smart materials that can be used in widely divergent fields. Reversible networks are currently being exploited for applications in tissue engineering, drug delivery, and soft robotics. They are also being utilized as low-calorie fat mimetics with melt-in-your-mouth textures, as well as being explored as potential scaffolds for three-dimensional (3D) printable food, among other applications. This review aims to gather representative examples of heat- and shear-reversible networks in the food science literature from the last 30 or so years, in other words, reversible food gels made either from linear biopolymers or from colloidal, particulate dispersions, including those that have been modified specifically to induce reversibility. An overview of the network mechanisms involved that impart reversibility, including a discussion of the strength and range of forces involved, will be highlighted. A model that explains why certain networks are thermoreversible while others are shear-reversible, and why others are both, will also be proposed. A fundamental understanding of these mechanisms will prove invaluable when designing reversible networks in the future, making possible the precise control of their properties, thus fostering innovative applications within the food industry and beyond.

Truffle species strongly shape their surrounding soil mycobiota in a Pinus armandii forest.

Truffles contribute to crucial soil systems dynamics, being involved in plentiful ecological functions important for ecosystems. Despite this, the interactions between truffles and their surrounding mycobiome remain unknown. Here, we investigate soil mycobiome differences between two truffle species, Tuber indicum (Ti) and Tuber pseudohimalayense (Tp), and their relative influence on surrounding soil mycobiota. Using traditional chemical analysis and ITS Illumina sequencing, we compared soil nutrients and the mycobiota, respectively, in soil, gleba, and peridium of the two truffle species inhabiting the same Pinus armandii forest in southwestern China. Tp soil was more acidic (pH 6.42) and had a higher nutrient content (total C, N content) than Ti soil (pH 6.62). Fungal richness and diversity of fruiting bodies (ascomata) and surrounding soils were significantly higher in Tp than in Ti. Truffle species recruited unique soil mycobiota around their ascomata: in Ti soil, fungal taxa, including Suillus, Alternaria, Phacidium, Mycosphaerella, Halokirschsteiniothelia, and Pseudogymnoascus, were abundant, while in Tp soil species of Melanophyllum, Inocybe, Rhizopogon, Rhacidium, and Lecanicillium showed higher abundances. Three dissimilarity tests, including adonis, anosim, and MRPP, showed that differences in fungal community structure between the two truffle species and their surrounding soils were stronger in Tp than in Ti, and these differences extended to truffle tissues (peridium and gleba). Redundancy analysis (RDA) further demonstrated that correlations between soil fungal taxa and soil properties changed from negative (Tp) to positive (Ti) and shifted from a moisture-driven (Tp) to a total N-driven (Ti) relationship. Overall, our results shed light on the influence that truffles have on their surrounding soil mycobiome. However, further studies are required on a broader range of truffle species in different soil conditions in order to determine causal relationships between truffles and their soil mycobiome.

Virulence genes and antimicrobial susceptibility in Salmonellaenterica serotypes isolated from swine production in Argentina.

Salmonella is a worldwide-distributed pathogen that affects both humans and animals and is usually associated with intensive animal production such as poultry and swine. This bacterium carries different virulence genes, whose expression favors its interaction with the host and may influence the course of the infection. Extended usage of antibiotics for metaphylaxis or prophylaxis and as growth promoters favors the emergence of multiresistant Salmonella strains. The aim of this work was to assess the association between the presence of virulence-associated genes and the antimicrobial resistance phenotype in Salmonella isolates obtained from swine intensive and backyard farms in Argentina during 2012-2018. A total of 59 Salmonella strains belonging to several serotypes were studied. All the strains carried the sopB and ssaQ genes, whereas more than 90% of the isolates carried the mgtC, avrA, and siiD genes. Some isolates also carried the bcfC, sodC1, gipA, sopE1 and spvC genes; however, their presence varied among them. Susceptibility to the antibiotics tested was diverse. Isolates from intensive farms were resistant to a larger number of antimicrobials than those from backyard farms and some of the strains showed high virulence potential and extensive antimicrobial resistance profiles. Continuous surveillance is essential to detect the emergence of strains that may represent a significant risk not only for animal production but also for the human population.

Genomic Variability of Phytophthora palmivora Isolates from Different Oil Palm Cultivation Regions in Colombia.

Palm oil is the most consumed vegetable oil globally, and Colombia is the largest palm oil producer in South America and fourth worldwide. However, oil palm plantations in Colombia are affected by bud rot disease caused by the oomycete Phytophthora palmivora, leading to significant economic losses. Infection processes by plant pathogens involve the secretion of effector molecules, which alter the functioning or structure of host cells. Current long-read sequencing technologies provide the information needed to produce high-quality genome assemblies, enabling a comprehensive annotation of effectors. Here, we describe the development of genomic resources for P. palmivora, including a high-quality genome assembly based on long and short-read sequencing data, intraspecies variability for 12 isolates from different oil palm cultivation regions in Colombia, and a catalog of over 1,000 candidate effector proteins. A total of 45,416 genes were annotated from the new genome assembled in 2,322 contigs adding to 165.5 Mbp, which represents an improvement of two times more gene models, 33 times better contiguity, and 11 times less fragmentation compared with currently available genomic resources for the species. Analysis of nucleotide evolution in paralogs suggests a recent whole-genome duplication event. Genetic differences were identified among isolates showing variable virulence levels. We expect that these novel genomic resources contribute to the characterization of the species and the understanding of the interaction of P. palmivora with oil palm and could be further exploited as tools for the development of effective strategies for disease control.

Comparison of serological methods with PCR-based methods for the diagnosis of community-acquired pneumonia caused by atypical bacteria.

BACKGROUND: The diagnosis of community-acquired pneumonia (CAP) caused by Legionella pneumophila, Mycoplasma pneumoniae, and Chlamydophila pneumoniae is traditionally based on cultures and serology, which have special requirements, are time-consuming, and offer delayed results that limit their clinical usefulness of these techniques. We sought to develop a multiplex PCR (mPCR) method to diagnosis these bacterial infections in CAP patients and to compare the diagnostic yields obtained from mPCR of nasopharyngeal aspirates (NPAs), nasopharyngeal swabs (NPSs), and induced sputum (IS) with those obtained with specific PCR commercial kits, paired serology, and urinary antigen. RESULTS: A total of 225 persons were included. Of these, 10 patients showed serological evidence of L. pneumophila infection, 30 of M. pneumoniae, and 18 of C. pneumoniae; 20 individuals showed no CAP. The sensitivities were mPCR-NPS = 23.1%, mPCR-IS = 57.1%, Seeplex®-IS = 52.4%, and Speed-oligo®-NPA/NPS = 11.1%, and the specificities were mPCR-NPS = 97.1%, mPCR-IS = 77.8%, Seeplex®-IS = 92.6%, and Speed-oligo®-NPA/NPS = 96.1%. The concordance between tests was poor (kappa <0.4), except for the concordance between mPCR and the commercial kit in IS (0.67). In individuals with no evidence of CAP, positive reactions were observed in paired serology and in all PCRs. CONCLUSIONS: All PCRs had good specificity but low sensitivity in nasopharyngeal samples. The sensitivity of mPCR and Seeplex® in IS was approximately 60%; thus, better diagnostic techniques for these three bacteria are required.

Cytokine/chemokine profiles in people with recent infection by Mycobacterium tuberculosis.

Introduction: The risk of progression to tuberculosis disease is highest within the first year after M. tuberculosis infection (TBI). We hypothesize that people with newly acquired TBI have a unique cytokine/chemokine profile that could be used as a potential biomarker. Methods: We evaluated socio-demographic variables and 18 cytokines/chemokines in plasma samples from a cohort of people deprived of liberty (PDL) in two Colombian prisons: 47 people diagnosed with pulmonary TB, 24 with new TBI, and 47 non-infected individuals. We performed a multinomial regression to identify the immune parameters that differentiate the groups. Results: The concentration of immune parameters changed over time and was affected by the time of incarceration. The concentration of sCD14, IL-18 and IP-10 differed between individuals with new TBI and short and long times of incarceration. Among people with short incarceration, high concentrations of MIP-3α were associated with a higher risk of a new TBI, and higher concentrations of Eotaxin were associated with a lower risk of a new TBI. Higher concentrations of sCD14 and TNF-α were associated with a higher risk of TB disease, and higher concentrations of IL-18 and MCP-1 were associated with a lower risk of TB disease. Conclusions: There were cytokines/chemokines associated with new TBI and TB disease. However, the concentration of immune mediators varies by the time of incarceration among people with new TBI. Further studies should evaluate the changes of these and other cytokines/chemokines over time to understand the immune mechanisms across the spectrum of TB.

Does One Size Fit All? Variations in the DNA Barcode Gaps of Macrofungal Genera.

The nuclear ribosomal internal transcribed spacer (nrITS) region has been widely used in fungal diversity studies. Environmental metabarcoding has increased the importance of the fungal DNA barcode in documenting fungal diversity and distribution. The DNA barcode gap is seen as the difference between intra- and inter-specific pairwise distances in a DNA barcode. The current understanding of the barcode gap in macrofungi is limited, inhibiting the development of best practices in applying the nrITS region toward research on fungal diversity. This study examined the barcode gap using 5146 sequences representing 717 species of macrofungi from eleven genera, eight orders and two phyla in datasets assembled by taxonomic experts. Intra- and inter-specific pairwise distances were measured from sequence and phylogenetic data. The results demonstrate that barcode gaps are influenced by differences in intra- and inter-specific variance in pairwise distances. In terms of DNA barcode behavior, variance is greater in the ITS1 than ITS2, and variance is greater in both relative to the combined nrITS region. Due to the difference in variance, the barcode gaps in the ITS2 region are greater than in the ITS1. Additionally, the taxonomic approach of "splitting" taxa into numerous taxonomic units produces greater barcode gaps when compared to "lumping". The results show variability in the barcode gaps between fungal taxa, demonstrating a need to understand the accuracy of DNA barcoding in quantifying species richness. For taxonomic studies, variability in nrITS sequence data supports the application of multiple molecular markers to corroborate the taxonomic and systematic delineation of species.

The ectomycorrhizal association of Tricholoma matsutake and two allied species, T. bakamatsutake and T. fulvocastaneum, with native hosts in subtropical China.

Accurate identification of edible ectomycorrhizal (ECM) mushrooms and their host trees in nature is key to commercial production for consumption. For the first time we describe the ectomycorrhizal association of the three most common species of edible matsutake mushrooms with their native host trees in Yunnan Province in China. We collected ECM samples from three different localities in subtropical forests known to be highly productive areas of Tricholoma. Additionally, we collected basidiomata of Tricholoma from the field and markets in Yunnan. ECM samples were analyzed using morphological and molecular methods. We conducted phylogenetic analyses of nuc rDNA internal transcribed spacer region ITS1-5.8S-ITS2 (ITS) and analyzed the intergenic spacer of cpDNA psbA-trnH to identify basidiomata and plant hosts, respectively. Three species of Tricholoma were identified: T. bakamatsutake, T. fulvocastaneum, and T. matsutake. Four ECM associations in the study area were detected: Tricholoma bakamatsutake + Castanopsis tibetana, T. fulvocastaneum + C. tibetana, T. fulvocastaneum + Pinus yunnanensis, and T. matsutake + P. yunnanensis. Detailed descriptions and illustrations of the ECM associations are presented.

Ethnomycological study on wild mushrooms in Pu'er Prefecture, Southwest Yunnan, China.

BACKGROUND: Yunnan is rich in fungal diversity and cultural diversity, but there are few researches on ethnomycology. In addition, extensive utilization of wild edible fungi (WEF), especially the ectomycorrhizal fungi, threatens the fungal diversity. Hence, this study aims to contribute to the ethnomycological knowledge in Pu'er Prefecture, Yunnan, China, including information on the fungal taxa presented in markets and natural habitats, with emphasis in ectomycorrhizal fungi (EMF). METHODS: Semi-structured interviews with mushroom vendors in markets and with mushroom collectors in natural habitats were conducted. Information related to local names, habitat, fruiting time, species identification, price, cooking methods and preservation methods of wild edible mushrooms were recorded. Wild edible fungi were collected from forests, and morphological and molecular techniques were used to identify fungal species. RESULTS: A total of 11 markets were visited during this study. The 101 species collected in the markets belonged to 22 families and 39 genera, and about 76% of them were EMF. A wealth of ethnomycological knowledge was recorded, and we found that participants in the 45-65 age group were able to judge mushroom species more accurately. Additionally, men usually had a deepest mushroom knowledge than women. A total of 283 species, varieties and undescribed species were collected from natural habitats, and about 70% of them were EMF. Mushroom species and recorded amounts showed correspondence between markets and the natural habitats on different months. CONCLUSION: The present study shows that Pu'er Prefecture is rich in local mycological knowledge and fungal diversity. However, it is necessary to continue the research of ethnomycological studies and to design and conduct dissemination of local knowledge in order to preserve it, since it currently remains mainly among the elderly population.

Modulating Functionality of Starch-Based Patchy Particles by Manipulating Architecture and Environmental Factors.

Starch as a food-grade thickener has been commonly used in food products to modulate textural properties. Improving viscosity-enhancing ability, so as to be able to use less starch for the same texture, has been considered as an approach to reduce the dietary consumption of carbohydrates. We have positively charged amaranth starch (∼1 µm) and negatively charged corn starch (>10 µm) and physically fused the particles together to create a starch with a heterogeneous pattern. This starch has a negatively charged main body, due to the larger corn particles, and positively charged patches from the amaranth starch. These patchy particles self-assembled through electrostatic interactions into a shear-reversible thickener. The impact of patchiness and charge density on material functionality was investigated. The degree of patchiness was controlled by manipulating the ratio between the two starches, and results showed that viscosity was reduced when the patchiness was higher. With the same patchy area, a higher charge density did not contribute to higher water-holding capacity. The more charged particles were able to enhance the viscosity, however, due to the stronger interparticle electrostatic interaction. The effects of environmental factors including pH level and ionic strength were also investigated, and the results showed that at extreme pH levels, or in the presence of Na+ or Ca2+, the charges on the starch particles were screened, and this inhibited interaction and reduced viscosity. The present work demonstrates that the texture of starch slurries can be fine-tuned by manipulating the degree of patchiness and the charge density of patchy particles. It also evaluates the application potential in food products with different pH levels and ionic strengths.

Starch Janus Particles: Bulk Synthesis, Self-Assembly, Rheology, and Potential Food Applications.

Although incredible progress in the field of Janus particles over the last three decades has delivered many promising smart-material prototypes, from cancer-targeting drug delivery vehicles to self-motile nanobots, their real-world applications have been somewhat tempered by concerns over scalability and sustainability. In this study, we adapt a simple, scalable 3D mask method to synthesize Janus particles in bulk using starch as the base material: a natural biopolymer that is safe, biocompatible, biodegradable, cheap, widely available, and versatile. Using this method, starch granules are first embedded on a wax droplet such that half of the starch is covered; then, the uncovered half is treated with octenyl succinic anhydride, after which the wax coating is removed. Janus particles with 49% Janus balance can be produced in this way and were observed to self-assemble into wormlike strings in water due to their hydrophobic/hydrophilic nature. Our Janus starch granules outperform the non-Janus controls as thickening and gelling agents: they exhibit a fourfold increase in water-holding capacity, a 30% lower critical caking concentration, and a viscosity greater by orders of magnitude. They also form gels that are much firmer and more stable. Starch Janus particles with these functional properties can be used as novel, lower-calorie, highly efficient, plant-based super-thickeners in the food industry, potentially reducing starch use in food by 55%.

Fabrication of Charged Self-Assembling Patchy Particles Templated with Partially Gelatinized Starch.

Starch, as a staple carbohydrate, is frequently used as a thickener to enhance food texture. As such, there is an increasing interest in studying starch modification to improve its thickening ability. Instead of the conventional mechanism of swelling-based thickening, the present work presents an alternative using starch-based patchy particles as a texturizer prepared through a bottom-up method by physically grafting small amaranth starch granules (∼1 µm) onto corn starch granules (>10 µm). After thermal treatment in aqueous ethanol, starches were partially gelatinized, and the particle stiffness was reduced. The corn starch and amaranth starch were modified to carry a negative charge and a positive charge, respectively. The hydrated swollen starch granules were centrifuged and dehydrated, which stitched particles together, forming a corona-shaped patchy structure with a negatively charged core and positively charged patches. The electrostatic interaction allowed particles to associate, and the pockets created in the flocs were able to trap more water. The enhanced water-holding capacity consequently contributed to a significantly higher storage modulus, loss modulus, and viscosity compared to the native starch and the mixed charged starch with the same blending ratio between amaranth and corn starch. The enhanced viscoelasticity was not affected by cooking and mechanical stress, which could be used as a shear-reversible thickener to modify texture with less raw ingredients, thus helping to reduce the amount of energy-dense starch in diets. This is the first time that the concept of patchy particles has been extended to food-grade ingredients with a facile and scalable method.

Gene expression profiling identifies candidate biomarkers for new latent tuberculosis infections. A cohort study.

OBJECTIVE: To determine the gene expression profile in individuals with new latent tuberculosis infection (LTBI), and to compare them with people with active tuberculosis (TB) and those exposed to TB but not infected. DESIGN: A prospective cohort study. Recruitment and follow-up were conducted between September 2016 to December 2018. Gene expression and data processing and analysis from April 2019 to April 2021. SETTING: Two male Colombian prisons. PARTICIPANTS: 15 new tuberculin skin test (TST) converters (negative TST at baseline that became positive during follow-up), 11 people that continued with a negative TST after two years of follow-up, and 10 people with pulmonary ATB. MAIN OUTCOME MEASURES: Gene expression profile using RNA sequencing from PBMC samples. The differential expression was assessed using the DESeq2 package in Bioconductor. Genes with |logFC| >1.0 and an adjusted p-value < 0.1 were differentially expressed. We analyzed the differences in the enrichment of KEGG pathways in each group using InterMiner. RESULTS: The gene expression was affected by the time of incarceration. We identified group-specific differentially expressed genes between the groups: 289 genes in people with a new LTBI and short incarceration (less than three months of incarceration), 117 in those with LTBI and long incarceration (one or more years of incarceration), 26 in ATB, and 276 in the exposed but non-infected individuals. Four pathways encompassed the largest number of down and up-regulated genes among individuals with LTBI and short incarceration: cytokine signaling, signal transduction, neutrophil degranulation, and innate immune system. In individuals with LTBI and long incarceration, the only enriched pathway within up-regulated genes was Emi1 phosphorylation. CONCLUSIONS: Recent infection with MTB is associated with an identifiable RNA pattern related to innate immune system pathways that can be used to prioritize LTBI treatment for those at greatest risk for developing active TB.

Induced sputum as an adequate clinical specimen for the etiological diagnosis of community-acquired pneumonia (CAP) in children and adolescents.

OBJECTIVES: This study aimed to evaluate the utility of induced sputum (IS) for the diagnosis of community-acquired pneumonia (CAP) in pediatric population. METHODS: This cross-sectional study included pediatric population aged between 1 month and 17 years who were hospitalized with a diagnosis of CAP in 13 hospitals in Colombia, in whom an IS sample was obtained. Gram staining, aerobic bacterial and mycobacterial culture tests, and polymerase chain reaction (PCR) for 6 atypical bacteria and 15 respiratory viruses were performed. We evaluated the quality of IS samples. RESULTS: IS samples were collected in 516 of 525 children included in this study. The median age was 32 months, 38.6% were younger than 2 years, and 40.9% were between 2 and 5 years. Two patients had transient hypoxemia during the procedure. The quality of the IS obtained was good in 48.4% and intermediate in 24.5%. Identification of a respiratory pathogen was achieved with an IS sample (with Gram staining, culture test, and PCR) in 372 of 516 children with CAP. CONCLUSION: Our study shows that IS is an adequate sample for the diagnosis of CAP in pediatric population that required hospitalization. The procedure was safe, well tolerated, and with better diagnostic yields compared with the rest of the samples obtained.

p8/TTDA overexpression enhances UV-irradiation resistance and suppresses TFIIH mutations in a Drosophila trichothiodystrophy model.

Mutations in certain subunits of the DNA repair/transcription factor complex TFIIH are linked to the human syndromes xeroderma pigmentosum (XP), Cockayne's syndrome (CS), and trichothiodystrophy (TTD). One of these subunits, p8/TTDA, interacts with p52 and XPD and is important in maintaining TFIIH stability. Drosophila mutants in the p52 (Dmp52) subunit exhibit phenotypic defects similar to those observed in TTD patients with defects in p8/TTDA and XPD, including reduced levels of TFIIH. Here, we demonstrate that several Dmp52 phenotypes, including lethality, developmental defects, and sterility, can be suppressed by p8/TTDA overexpression. TFIIH levels were also recovered in rescued flies. In addition, p8/TTDA overexpression suppressed a lethal allele of the Drosophila XPB homolog. Furthermore, transgenic flies overexpressing p8/TTDA were more resistant to UV irradiation than were wild-type flies, apparently because of enhanced efficiency of cyclobutane-pyrimidine-dimers and 6-4 pyrimidine-pyrimidone photoproducts repair. This study is the first using an intact higher-animal model to show that one subunit mutant can trans-complement another subunit in a multi-subunit complex linked to human diseases.

Two new species and a new record of yellow Cantharellus from tropical Quercus forests in eastern Mexico with the proposal of a new name for the replacement of Craterellus confluens.

Two new species of yellow Cantharellus and a new record of Cantharellus tabernensis associated with tropical species of Quercus are presented, based on the taxonomic study of fresh specimens and in a phylogenetic analysis of transcription elongation factor 1-alpha (tef-1α) and the large subunit of the ribosome (nLSU) sequences. One of the new species proposed here, corresponds to a choice edible mushroom, which, in our molecular phylogeny, resulted in it being related to the group of species around C. lateritius and sister with Craterellus confluens type specimen. This latter is here formally transferred to Cantharellus and consequently a new name, Cantharellus furcatus, is proposed to replace the homonym Cantharellus confluens (Schwein.) Schwein. 1834 a later synonym of Byssomerulius corium. Detailed macroscopic and microscopic descriptions accompanied with illustrations and a taxonomic discussion are presented for each species.

Incidence and Risk Factors Associated with Latent Tuberculosis Infection and Pulmonary Tuberculosis among People Deprived of Liberty in Colombian Prisons.

People deprived of liberty (PDL) are at high risk of acquiring Mycobacterium tuberculosis infection (latent tuberculosis infection [LTBI]) and progressing to active tuberculosis (TB). We sought to determine the incidence rates and factors associated with LTBI and active TB in Colombian prisons. Using information of four cohort studies, we included 240 PDL with two-step tuberculin skin test (TST) negative and followed them to evaluate TST conversion, as well as, 2,134 PDL that were investigated to rule out active TB (1,305 among people with lower respiratory symptoms of any duration, and 829 among people without respiratory symptoms and screened for LTBI). Latent tuberculosis infection incidence rate was 2,402.88 cases per 100,000 person-months (95% CI 1,364.62-4,231.10) in PDL with short incarceration at baseline, and 419.66 cases per 100,000 person-months (95% CI 225.80-779.95) in individuals with long incarceration at baseline (who were enrolled for the follow after at least 1 year of incarceration). The TB incidence rate among PDL with lower respiratory symptoms was 146.53 cases/100,000 person-months, and among PDL without respiratory symptoms screened for LTBI the incidence rate was 19.49 cases/100,000 person-months. History of Bacillus Calmette-Guerin vaccination decreased the risk of acquiring LTBI among PDL who were recently incarcerated. Female sex, smoked drugs, and current cigarette smoking were associated with an increased risk of developing active TB. This study shows that PDL have high risk for LTBI and active TB. It is important to perform LTBI testing at admission to prison, as well as regular follow-up to control TB in prisons.

Multiresistant and blaCTX-M-14-Carrying Salmonella ser. Typhimurium Isolated During a Salmonellosis Outbreak in an Equine Hospital in Argentina.

Salmonella spp. causes digestive clinical signs in horses. Foals and hospitalized animals are more susceptible to the disease. Nowadays, the report of multidrug-resistant Salmonella spp. producer of extended-spectrum ß-lactamases, is more frequent. The aim of this work was to study the clonal relationship and antimicrobial susceptibility profiles among Salmonella ser. Typhimurium isolates, obtained during a salmonellosis outbreak in an Argentinian equine hospital. Thus, in 2017, we studied the genotypic profiles and the susceptibility to antimicrobials of the strains isolated from three animals with diarrhea in an equine hospital of Argentina. The pulsotype identified by pulsed-field gel electrophoresis was the same among the isolates. Also, this pulsotype had been previously detected in human and porcine isolates, suggesting the circulation of the same strains in different species. Multidrug-resistant isolates with different ß-lactam susceptibility profiles were identified and blaCTX-M-14 was detected for the first time from an isolate of equine-origin in Argentina. Salmonella ser. Typhimurium is an important pathogen in public and veterinary health, so our results emphasize the relevance of appropriate measures to prevent and control this disease. Furthermore, routine antibiotic susceptibility tests of local strains are needed to improve the empiric treatment of equine salmonellosis.

Molecular characterization and antimicrobial resistance profiles of Salmonella Heidelberg isolates from poultry.

In the last 10 years, Salmonella Heidelberg has been extensively isolated from poultry in several countries. In this context, molecular characterization is essential to understand whether the strains have entered the farms from a single or several sources. Thus, the aim of this study was to determine the genetic relationship and antimicrobial susceptibility of S. Heidelberg strains isolated between 2011 and 2012 from broiler farms belonging to three integrated poultry companies located in Argentina. The genetic relatedness of the S. Heidelberg isolates was determined by pulsed-field gel electrophoresis (PFGE), and resistance to 21 antimicrobials was determined by the disc diffusion method. The isolates were assigned to four PFGE patterns. Most of the strains showed 100% similarity and belonged to the same integrated poultry company. This PFGE pattern was also prevalent in S. Heidelberg strains isolated from humans in several provinces of Argentina, which suggests an epidemiological association between human and poultry strains. All the isolates were classified as multidrug-resistant (MDR), and no clear relationship was observed between PFGE and resistance patterns. S. Heidelberg strains may circulate among farms from the same integrated company due to common sources of contamination. To guarantee the safety of the poultry product for the consumers, holistic approaches including surveillance of Salmonella throughout the production chain together with control measures are crucial.