Publications by authors named "Alejandro Pina-Iturbe"

is a leading cause of foodborne illnesses globally, with significant mortality rates, especially among vulnerable populations. Traditional serotyping methods for are accurate but expensive, resource-intensive, and time-consuming, necessitating faster and more reliable alternatives. This study evaluates the IR Biotyper, a Fourier-transform infrared spectroscopy system, in differentiating serovars.

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A Salmonella enterica serovar Abony outbreak occurred during January-April 2024 in Chile. Genomic evidence indicated that the outbreak strain was a clone of reference strain WDCM 00029, which is routinely used in microbiological quality control tests. When rare or unreported serovars cause human infections, clinicians and health authorities should request strain characterization.

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Article Synopsis
  • Multidrug-resistant (MDR) Infantis is a globally spread pathogen linked to poultry consumption, with rising human infections in Chile, prompting a study on its genomic epidemiology and resistance profiles.
  • Researchers sequenced and analyzed 396 genomes of Infantis from various sources in Chile, adding to existing data for a total of 440 genomes from 2009 to 2022.
  • The study revealed clusters of related isolates, particularly the HC20_343 cluster, known for carrying multiple antimicrobial resistance genes and a strong link across environmental, animal, food, and human sources, indicating a need for better surveillance and control measures.
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The ICEKp258.2 genomic island (GI) has been proposed as an important factor for the emergence and success of the globally spread carbapenem-resistant sequence type (ST) 258. However, a characterization of this horizontally acquired element is lacking.

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Excisable genomic islands (EGIs) are horizontally acquired genetic elements that harbor an array of genes with diverse functions. ROD21 is an EGI found integrated in the chromosome of serovar Enteritidis ( ser. Enteritidis).

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Background: The Omicron variant has challenged the control of the COVID-19 pandemic due to its immuno-evasive properties. The administration of a booster dose of a SARS-CoV-2 vaccine showed positive effects in the immunogenicity against SARS-CoV-2, effect that is even enhanced after the administration of a second booster.

Methods: During a phase-3 clinical trial, we evaluated the effect of a second booster of CoronaVac®, an inactivated vaccine administered 6 months after the first booster, in the neutralization of SARS-CoV-2 (n = 87).

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Multiple vaccines against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) have been evaluated in clinical trials. However, trials addressing the immune response in the pediatric population are scarce. The inactivated vaccine CoronaVac has been shown to be safe and immunogenic in a phase 1/2 clinical trial in a pediatric cohort in China.

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Article Synopsis
  • CoronaVac is an inactivated SARS-CoV-2 vaccine approved by the WHO, showing decreased immune response over time after the initial two doses.
  • A study in Chile tested the effects of a booster dose on immune response to the Delta and Omicron variants, finding significant increases in neutralizing antibodies and T cell activation four weeks later.
  • These findings indicate that a booster dose of CoronaVac effectively enhances immunity against SARS-CoV-2 and its variants, suggesting it provides adequate protection for adults.
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Bacillus Calmette-Guérin (BCG) is a live attenuated vaccine mainly administered to newborns and used for over 100 years to prevent the disease caused by (). This vaccine can induce immune response polarization towards a Th1 profile, which is desired for counteracting , other mycobacteria, and unrelated intracellular pathogens. The vaccine BCG has been used as a vector to express recombinant proteins and has been shown to protect against several diseases, particularly respiratory viruses.

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Genomic islands (GIs) are horizontally transferred elements that shape bacterial genomes and contributes to the adaptation to different environments. Some GIs encode an integrase and a recombination directionality factor (RDF), which are the molecular GI-encoded machinery that promotes the island excision from the chromosome, the first step for the spread of GIs by horizontal transfer. Although less studied, this process can also play a role in the virulence of bacterial pathogens.

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Carbapenem-resistant ST258 (CRKP-ST258) are a global concern due to their rapid dissemination, high lethality, antibiotic resistance and resistance to components of the immune response, such as neutrophils. Neutrophils are major host mediators, able to kill well-studied and antibiotic-sensitive laboratory reference strains of . However, CRKP-ST258 are able to evade neutrophil phagocytic killing, persisting longer in the host despite robust neutrophil recruitment.

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Acquisition of mobile elements by horizontal gene transfer can play a major role in bacterial adaptation and genome evolution by providing traits that contribute to bacterial fitness. However, gaining foreign DNA can also impose significant fitness costs to the host bacteria and can even produce detrimental effects. The efficiency of horizontal acquisition of DNA is thought to be improved by the activity of xenogeneic silencers.

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Genomic Islands (GIs) are DNA regions acquired through horizontal gene transfer that encode advantageous traits for bacteria. Many GIs harbor genes that encode the molecular machinery required for their excision from the bacterial chromosome. Notably, the excision/integration dynamics of GIs may modulate the virulence of some pathogens.

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