Liver abscess induced by intestinal hypervirulent through down-regulation of tryptophan-IPA-IL22 axis.

Hypervirulent (hvKp) is a significant causative agent of invasive hepatic abscess syndrome in Asia, presenting substantial clinical challenges due to its intricate pathogenesis. This study revealed the crucial role of the gut microbiota in fortifying the host's defense against hvKp infection by enhancing interleukin-22 (IL-22), probably through regulating downstream antimicrobial peptides such as Reg3β. In antibiotic-treated mice, we observed that gut microbiota disruption impaired the transformation of tryptophan to indole, a key ligand for the aryl hydrocarbon receptor (AhR), consequently affecting the regulatory functions of IL-22.

Dissemination and characteristics of carbapenem-resistant in nine district hospitals in southwestern China.

Background: Carbapenem-resistant (CRKP) is epidemically transmitted globally, but few studies focused on the prevalence in district-level hospitals. In this study, we investigated CRKP strains collected from nine district hospitals from September 2019 to September 2020, aiming to determine the resistance mechanisms, virulence profiles, and molecular epidemiological characteristics of CRKP in district hospitals in Southwest China.

Methods: A total of 51 CRKP strains were collected from 9 district-level hospitals.

Transcriptome and metabolome profiling in different stages of infestation of Eucalyptus urophylla clones by Ralstonia solanacearum.

Eucalyptus urophylla is an economically important tree species that widely planted in tropical and sub-tropical areas around the world, which suffers significant losses due to Ralstonia solanacearum. However, little is known about the molecular mechanism of pathogen-response of Eucalyptus. We collected the vascular tissues of a E.

Inactivation of Clinically Frequently Used Antimicrobial Agents By BacT/ALERT FAN Plus and BACTEC Aerobic and Anaerobic Culture Media in Simulated Blood Cultures: First Comparative Evaluation in China Mainland.

Purpose: To evaluate the antimicrobial inactivation capabilities of BacT/ALERT (FA Plus and FN Plus) and BACTEC (Plus Aerobic/F and Lytic/10 Anaerobic/F) media.

Patients And Methods: The inactivation capabilities of the commercial blood culture media were compared using 21 microorganism-antimicrobial combinations in simulated adult blood cultures.

Results: BacT/ALERT culture media demonstrated higher detection rates than the BACTEC culture media.

Epidemiology and risk factors of rectal colonization of carbapenemase-producing Enterobacteriaceae among high-risk patients from ICU and HSCT wards in a university hospital.

Background: Nosocomial carbapenemase-producing Enterobacterieceae (CPE) infections constitute a major global health concern and are associated with increased morbidity and mortality. Rectal colonization with CPE is a risk factor for bacterial translocation leading to subsequent endogenous CPE infections. This prospective observational study was aimed to investigate the prevalence and epidemiology of rectal colonization of CPE, the carbapenemase genotypes, and to identify the independent risk factors for the acquisition of CPE colonization in high-risk patients from ICU and HSCT wards in a university hospital in China.

Evaluation of Modified Rapid Carbapenem Inactivation Method (mrCIM) Combined with Rapid EDTA-Modified Carbapenem Inactivation Method (reCIM) to Detect Carbapenemase and Distinguish Metallo-Carbapenemase in Within Four Hours.

Purpose: To develop a rapid EDTA-modified carbapenem inactivation method (reCIM) combined with modified rapid carbapenem inactivation method (mrCIM) to detect carbapenemase and distinguish metallo-β-lactamases from carbapenemases in in 4 hrs.

Materials And Methods: The sensitivities and specificities of mrCIM and reCIM were retrospectively evaluated in 247 carbapenem-resistant of which 107 were carbapenemase producers confirmed by PCR and sequencing. In addition, mrCIM and reCIM were prospectively evaluated with 47 carbapenem-resistant enterobacterial isolates.

Eight-Year Surveillance of Uropathogenic in Southwest China.

Purpose: To assess antimicrobial resistance profiles change in uropathogenic (UPEC) during an 8-year period, especially extended-spectrum β-lactamase (ESBL)-producing and carbapenem-resistant isolates.

Materials And Methods: A retrospective observational study of urinary tract infections (UTIs) was performed in a territory hospital between 2012 and 2019. Isolates were identified using matrix-assisted laser desorption/ionization time of flight mass spectrometry or the VITEK 2 Compact system.

Corrigendum: Carbapenem-Resistant in Southwest China: Molecular Analysis of Resistance and Risk Factors for Infections Caused by NDM-1-Producers.

[This corrects the article DOI: 10.3389/fmicb.2018.

Protective Regulatory T Cell Immune Response Induced by Intranasal Immunization With the Live-Attenuated Pneumococcal Vaccine SPY1 the Transforming Growth Factor-β1-Smad2/3 Pathway.

Vaccine effectiveness is mainly determined by the mechanism mediating protection, emphasizing the importance of unraveling the protective mechanism for novel pneumococcal vaccine development. We previously demonstrated that the regulatory T cell (Treg) immune response has a protective effect against pneumococcal infection elicited by the live-attenuated pneumococcal vaccine SPY1. However, the mechanism underlying this protective effect remains unclear.

Carbapenem-Resistant in Southwest China: Molecular Analysis of Resistance and Risk Factors for Infections Caused by NDM-1-Producers.

Carbapenem-resistant (CRE) has been considered a serious global threat, but carbapenem resistance remains relatively uncommon in , especially in China. The aim of this study was to characterize carbapenem-resistant (CR-ECL) isolates from 2012 to 2016 in Southwest China. Our study revealed that 20 (15.

spd1672, a novel in vivo-induced gene, affects inflammatory response in a murine model of Streptococcus pneumoniae infection.

spd1672, a novel Streptococcus pneumoniae (hereinafter S. pn) gene induced in vivo, has been identified to contribute to the virulence of S. pn; however, the role of spd1672 during host innate immune reaction against S.

Heteroresistance to carbapenems in invasive Pseudomonas aeruginosa infections.

Heteroresistance is common in a variety of microbes, however carbapenem heteroresistance among invasive Pseudomonas aeruginosa infections has not been thoroughly characterised to date. The objective of this study was to investigate the mechanisms, molecular epidemiology and risk factors for invasive carbapenem-heteroresistant P. aeruginosa (CHPA) infections between 2011 and 2015 in Chongqing, China.

Multidrug Resistance Mechanisms of Carbapenem Resistant Klebsiella pneumoniae Strains Isolated in Chongqing, China.

Background: Carbapenem-resistant Klebsiella pneumoniae (CRKP) is considered a serious global threat. However, little is known regarding the multidrug resistance (MDR) mechanisms of CRKP. This study investigated the phenotypes and MDR mechanisms of CRKP and identified their clonal characteristics.

Evaluation of Six Phenotypic Methods for the Detection of Carbapenemases in Gram-Negative Bacteria With Characterized Resistance Mechanisms.

Background: We compared the performance of the modified Hodge test (MHT), Triton Hodge test (THT), Carba NP test (CNPt), simplified Carba NP test (CNPt-direct), blue-Carba NP test (BCT), and carbapenem inactivation method (CIM) for rapid and accurate carbapenemase detection.

Methods: The methods were evaluated by using 256 gram-negative isolates, including 197 Enterobacteriaceae (79 Enterobacter spp., 74 Klebsiella spp.

A corrected effective density fluid model for gassy sediments.

A corrected effective density fluid model is developed for predicting sound speed dispersion and attenuation coefficient in gassy sediments. An acoustic experiment was undertaken to measure the attenuation coefficient in a frequency band of 600 to 3000 Hz in gassy unsaturated sand. The measured frequency spectra of the attenuation coefficient show four peaks due to bubble resonance.

Differential distribution patterns of ammonia-oxidizing archaea and bacteria in acidic soils of Nanling National Nature Reserve forests in subtropical China.

In addition to ammonia-oxidizing bacteria (AOB) the more recently discovered ammonia-oxidizing archaea (AOA) can also oxidize ammonia, but little is known about AOA community structure and abundance in subtropical forest soils. In this study, both AOA and AOB were investigated with molecular techniques in eight types of forests at surface soils (0-2 cm) and deep layers (18-20 cm) in Nanling National Nature Reserve in subtropical China. The results showed that the forest soils, all acidic (pH 4.

[Identification of a point mutation in the promoter region of cps operon responsible for capsular polysaccharide deficiency in Streptococcus pneumniae SPY1].

Objective: To determine if the point mutation of nt313713 T --> C in the promoter region of capsular polysaccharide biosynthesis (cps) operon is responsible for the deficiency of capsular polysaccharide in S. pneumoniae SPY1 strain.

Methods: Western blot was used to compare the amounts of capsular polysaccharide between the wild-type strain and SPY1 strain.

Retrospective analysis of hospital-acquired linezolid-nonsusceptible enterococci infection in Chongqing, China, 2011-2014.

Background: Linezolid-nonsusceptible enterococci (LNSE) is an increasingly emerging multidrug-resistant pathogen, and the caused nosocomial infections are difficult to manage. However, data on the host-related risk factors and clinical outcomes for LNSE infection are poorly characterized.

Methods: A retrospective case-case-control study of risk factors and clinical outcomes of hospitalized patients with LNSE infection during the period 2011-2014 was conducted in a teaching hospital in Chongqing, China.

Epidemiology, antifungal susceptibilities, and risk factors for invasive candidiasis from 2011 to 2013 in a teaching hospital in southwest China.

Background: Invasive candidiasis (IC) is the most common cause of invasive fungal infections. Identification of risk factors for such infection may help in the empirical therapeutic decision-making process. We conducted this study to characterize the clinical epidemiology of such infection and to differentiate risk factors between Candida albicans and Candida non-albicans species.

Interleukin 4 Deficiency Reverses Development of Secondary Pseudomonas aeruginosa Pneumonia During Sepsis-Associated Immunosuppression.

Background: Interleukin 4 (IL-4) is an important cytokine that may modulate development of secondary bacterial pneumonia during sepsis-induced immunosuppression.

Methods: We established an experimental model of cecal ligation and puncture (CLP)-induced sublethal polymicrobial sepsis followed by secondary Pseudomonas aeruginosa pulmonary infection,

Results:  IL-4-deficient mice that underwent CLP were resistant to secondary pulmonary P. aeruginosa infection.

Mucosal immunization with the live attenuated vaccine SPY1 induces humoral and Th2-Th17-regulatory T cell cellular immunity and protects against pneumococcal infection.

Mucosal immunization with attenuated vaccine can protect against pneumococcal invasion infection, but the mechanism was unknown. Our study found that mucosal delivery with the live attenuated SPY1 vaccine strain can confer T cell- and B cell-dependent protection against pneumococcal colonization and invasive infection; yet it is still unclear which cell subsets contribute to the protection, and their roles in pneumococcal colonization and invasion remain elusive. Adoptive transfer of anti-SPY1 antibody conferred protection to naive μMT mice, and immune T cells were indispensable to protection examined in nude mice.

Characterization of carbapenemases, extended spectrum β-lactamases, quinolone resistance and aminoglycoside resistance determinants in carbapenem-non-susceptible Escherichia coli from a teaching hospital in Chongqing, Southwest China.

Carbapenem-resistant Escherichiacoli isolates harboring carbapenemases or combining an extended-spectrum β-lactamase (ESBL) enzyme with loss of porins present an increasingly urgent clinical danger. Combined resistance to aminoglycosides and fluoroquinolones in carbapeneme non-susceptible (CNS) isolates will inevitably create problems. In the current study, we characterized the carbapenemases and ESBLs, and the prevalence of quinolone resistance determinants and aminoglycoside resistance determinants in carbapenem-non-susceptible (CNS) E.

Serotype-independent protection against pneumococcal infections elicited by intranasal immunization with ethanol-killed pneumococcal strain, SPY1.

The 23-valent polysaccharide vaccine and the 7-valent pneumococcal conjugate vaccine are licensed vaccines that protect against pneumococcal infections worldwide. However, the incidence of pneumococcal diseases remains high in low-income countries. Whole-cell vaccines with high safety and strong immunogenicity may be a favorable choice.

Mucosal immunization with recombinant fusion protein DnaJ-ΔA146Ply enhances cross-protective immunity against Streptococcus pneumoniae infection in mice via interleukin 17A.

Pneumolysin (Ply) and its variants are protective against pneumococcal infections in animal models, and as a Toll-like receptor 4 agonist, pneumolysin has been reported to be a mucosal adjuvant. DnaJ has been approved as a useful candidate vaccine protein; we therefore designed novel fusion proteins of DnaJ with a form of Ply that has a deletion of A146 (ΔA146Ply-DnaJ [the C terminus of ΔA146Ply connected with the N terminus of DnaJ] and DnaJ-ΔA146Ply [the C terminus of DnaJ connected with the N terminus of ΔA146Ply]) to test whether they are protective against focal and lethal pneumococcal infections and their potential protective mechanisms. The purified proteins were used to intranasally immunize the animals without additional adjuvant.