Publications by authors named "Paul A Cardenas"

Human populations can be affected in unpredictable ways by the emergence and spread of zoonotic diseases. The COVID-19 (coronavirus disease of 2019) pandemic was a reminder of how devastating these events can be if left unchecked. However, once they have spread globally, the impact of these diseases when entering non-exposed wildlife populations is unknown.

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Introduction: The hygiene hypothesis identified a relationship between living in rural areas and acquiring protective environmental factors against the development of asthma and atopy. In our previous study, we found a correlation between particular bacterial species and early-onset wheezing in infants from the rural tropics of Ecuador who were corticosteroid-naïve and had limited antibiotic exposure. We now describe a longitudinal study of infants conducted to determine the age-related changes of the microbiome and its relationship with wheezing.

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Objectives: The paediatric gut microbiota is a reservoir of antimicrobial resistance genes. Environmental factors such as a child's exposure to faecal contamination and antimicrobial resistance genes of animal origin likely shape the resistome of infants and children. This study measured how different levels of exposure to domestic or food animals affect the structure of the intestinal resistome in children between 1 and 7 years of age.

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Objectives: The gastrointestinal tract constitutes a complex and diverse ecosystem. Escherichia coli is one of the most frequently studied and characterised species in the gut ecosystem; nevertheless, there has been little research to determine their diversity and population dynamics in the intestines of children over time. We analysed the turnover or dominant E.

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Background: The gut microbiota is a significant reservoir of antimicrobial resistance genes (ARGs). The use and misuse of antimicrobials can select multi-resistant bacteria and modify the repertoire of ARGs in the gut. Developing effective interventions to manipulate the intestinal resistome would allow us to modify the antimicrobial resistance risk.

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Background: Intestinal microbiota are recognized as an organ with important physiological functions whose alterations have been associated with common diseases including inflammatory intestinal conditions, malnutrition, type-2 diabetes, and cardiovascular diseases. The composition and function of the microbiota in the distal part of the intestine has been mainly described, while there is limited information on the small intestine microbiota. The objective of the present study was to describe the duodenal microbiome in individuals with dyspepsia in the presence or absence of Helicobacter pylori gastric infection.

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Introduction: Carbapenem resistance in members of order Enterobacterales is a growing public health problem causing high mortality in developing and industrialized countries. Its emergence and rapid propagation worldwide was due to both intercontinental spread of pandemic strains and horizontal dissemination via mobile genetic elements (MGE) such as plasmids and transposons.

Objective: To describe MGE carrying carbapenem resistance genes in Enterobacterales which have been reported in South America.

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Conventional therapy for H. pylori infection includes the combination of antibiotics and a proton-pump inhibitor. Addition of probiotics as adjuvants for H.

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Most studies on autism spectrum disorder (ASD) risk factors have been conducted in developed countries where ethnicity and environment are different than in developing countries. We compared nutritional status, immune response and microbiota composition in mestizo children with ASD with matched controls in Ecuador. Twenty-five cases and 35 controls were matched by age, sex and school location.

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Objectives: Klebsiella pneumoniae is an opportunistic pathogen associated with nosocomial infections worldwide. Isolates with a K. pneumoniae carbapenemase (KPC)-producing phenotype show reduced susceptibility to first-choice antibiotics.

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Microscopic examination is the standard method for diagnosis of cutaneous and mucocutaneous leishmaniasis despite its low sensitivity. This study compared the diagnosis efficacy of microscopic examination versus polymerase chain reaction (PCR)-based methods and DNA sequencing using whole blood and skin lesion samples from patients with suspected leishmaniasis. The presence of Leishmania was determined by microscopy and amplification of 18S ribosomal RNA gene from blood and skin samples of 22 patients.

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Background: The lower airways harbor a community of bacterial species which is altered in asthma.

Objectives: We examined whether the lower airway microbiota were related to measures of asthma severity.

Methods: We prospectively recruited 26 severe asthma, 18 non-severe asthma and 12 healthy subjects.

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Staphylococcus aureus is a frequent cause of nosocomial pneumonia and bacteremia worldwide. Classical and molecular epidemiology approaches were used to study a S. aureus outbreak in the intensive care unit (ICU) of one of the largest public hospitals in Quito.

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Background: Observations that the airway microbiome is disturbed in asthma may be confounded by the widespread use of antibiotics and inhaled steroids. We have therefore examined the oropharyngeal microbiome in early onset wheezing infants from a rural area of tropical Ecuador where antibiotic usage is minimal and glucocorticoid usage is absent.

Materials And Methods: We performed pyrosequencing of amplicons of the polymorphic bacterial 16S rRNA gene from oropharyngeal samples from 24 infants with non-infectious early onset wheezing and 24 healthy controls (average age 10.

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Hematopoietic stem cell transplantation (HSCT) has been utilized for treatment of many hematologic malignancies, genetic and metabolic disorders, and hemoglobinopathies such as sickle cell disease and thalassemia. It also induces donor-specific tolerance to organ and tissue transplants. The widespread success of HSCT is hampered by the toxicities of immunosuppression and development of graft-versus-host disease (GVHD).

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