The Metabolic Adaptation in Response to Nitrate Is Critical for Actinobacillus pleuropneumoniae Growth and Pathogenicity under the Regulation of NarQ/P.

Nitrate metabolism is an adaptation mechanism used by many bacteria for survival in anaerobic environments. As a by-product of inflammation, nitrate is used by the intestinal bacterial pathogens to enable gut infection. However, the responses of bacterial respiratory pathogens to nitrate are less well understood. Actinobacillus pleuropneumoniae is an important bacterial respiratory pathogen of swine. Previous studies have suggested that adaptation of A. pleuropneumoniae to anaerobiosis is important for infection. In this work, A. pleuropneumoniae growth and pathogenesis in response to the nitrate were investigated. Nitrate significantly promoted A. pleuropneumoniae growth under anaerobic conditions in vitro and lethality in mice. By using narQ and narP deletion mutants and single-residue-mutated complementary strains of ΔnarQ, the two-component system NarQ/P was confirmed to be critical for nitrate-induced growth, with Arg50 in NarQ as an essential functional residue. Transcriptome analysis showed that nitrate upregulated multiple energy-generating pathways, including nitrate metabolism, mannose and pentose metabolism, and glycerolipid metabolism via the regulation of NarQ/P. Furthermore, narQ, narP, and its target gene encoding the nitrate reductase Nap contributed to the pathogenicity of A. pleuropneumoniae. The Nap inhibitor tungstate significantly reduced the survival of A. pleuropneumoniae in vivo, suggesting that Nap is a potential drug target. These results give new insights into how the respiratory pathogen A. pleuropneumoniae utilizes the alternative electron acceptor nitrate to overcome the hypoxia microenvironment, which can occur in the inflammatory or necrotic infected tissues.

Perceived susceptibility to COVID-19 infection and narcissistic traits.

People's perceived susceptibility to illnesses plays a key role in determining whether or not to take protective measures. However, self-enhancing biases hinder accurate susceptibility perceptions, leaving some individuals to feel invulnerable in the face of acute health risks. Since such biases are prominent characteristics of individuals with narcissistic personality traits, this article empirically examined whether low perceived susceptibility of infection with COVID-19 is related to subclinical narcissism, as measured with the Narcissistic Personality Inventory (NPI-16) and the Narcissism Admiration and Rivalry Questionnaire (NARQ). We report the findings from a worldwide sample (N = 244), a UK sample before governmental pandemic restrictions (N = 261), a UK sample after restrictions (N = 261) and a pooled data analysis (N = 766). Overall, grandiose narcissism as measured with the NPI-16 predicted lower perceived susceptibility of infection, also after controlling for age and gender, whereas the NARQ Admiration subscale predicted higher perceived susceptibility. The findings are discussed in the light of theoretical and policy implications.

Construct validation of the Narcissistic Admiration and Rivalry Questionnaire in Spanish-speaking countries: Assessment of the reliability, structural and external validity and cross-cultural equivalence.

A recent re-operationalisation of grandiose narcissism has resulted in the distinction of two narcissistic strategies based on the cognitive, affective-motivational and behavioural dynamics: admiration (assertive self-enhancement) and rivalry (antagonistic self-protection). The Narcissistic Admiration and Rivalry Questionnaire (NARQ) was developed to assess this model with two higher-order dimensions. However, cross-validations of the NARQ have not been extensively conducted across diverse population groups and languages. This study aimed to test the internal and external validity (through the relation with envy and self-esteem), reliability and cross-cultural equivalence of the Spanish version of the NARQ. The psychometric properties were evaluated in a Spanish sample (N = 310), and cross-cultural equivalence was tested in participants from Chile (N = 234) and Colombia (N = 256). The results supported the reliability and validity of the Spanish NARQ, as well as the cross-cultural equivalence across Spanish-speaking countries. In addition, we discuss obtained differences across Spanish, Chilean and Colombian sample within two narcissistic strategies.