Characterization of Newly Isolated Bacteriophages Targeting Carbapenem-Resistant Klebsiella pneumoniae.

Klebsiella pneumoniae, a Gram-negative opportunistic pathogen, is increasingly resistant to carbapenems in clinical settings. This growing problem necessitates the development of alternative antibiotics, with phage therapy being one promising option. In this study, we investigated novel phages targeting carbapenem-resistant Klebsiella pneumoniae (CRKP) and evaluated their lytic capacity against clinical isolates of CRKP.

H-NS is a Transcriptional Repressor of the CRISPR-Cas System in Acinetobacter baumannii ATCC 19606.

Acinetobacter baumannii is a multidrug-resistant opportunistic pathogen primarily associated with hospital-acquired infections. The bacterium can gain multidrug resistance through several mechanisms, including horizontal gene transfer. A CRISPR-Cas system including several Cas genes could restrict the horizontal gene transfer.

Isolation and Characterization of Novel Bacteriophages to Target Carbapenem-Resistant .

The spread of multidrug-resistant in hospitals and nursing homes poses serious healthcare challenges. Therefore, we aimed to isolate and characterize lytic bacteriophages targeting carbapenem-resistant (CRAB). Of the 21 isolated phages, 11 exhibited potent lytic activities against clinical isolates of CRAB.

Therapeutic Phage Candidates for Targeting Prevalent Sequence Types of Carbapenem-Resistant .

Carbapenem-resistant (CREC) is a global threat to public health; therefore, alternative treatment options are urgently needed. Bacteriophages have emerged as promising candidates for combating CREC infections. This study aimed to investigate the genetic basis of phage sensitivity in CREC by evaluating carbapenem resistance among multidrug-resistant (MDR) isolated in Daegu, South Korea and analyzing their sequence types (STs) with phage susceptibility spectra.

Inhibition of Granule Cell Dispersion and Seizure Development by Astrocyte Elevated Gene-1 in a Mouse Model of Temporal Lobe Epilepsy.

Although granule cell dispersion (GCD) in the hippocampus is known to be an important feature associated with epileptic seizures in temporal lobe epilepsy (TLE), the endogenous molecules that regulate GCD are largely unknown. In the present study, we have examined whether there is any change in AEG-1 expression in the hippocampus of a kainic acid (KA)-induced mouse model of TLE. In addition, we have investigated whether the modulation of astrocyte elevated gene-1 () expression in the dentate gyrus (DG) by intracranial injection of adeno-associated virus 1 (AAV1) influences pathological phenotypes such as GCD formation and seizure susceptibility in a KA-treated mouse.

PmrAB controls virulence-associated traits and outer membrane vesicle biogenesis in Acinetobacter baumannii.

The PmrAB two-component system modulates colistin resistance in Acinetobacter baumannii, but its association with the virulence traits of this bacterium remains uncharacterized. This study explored the role of A. baumannii PmrAB in surface motility, biofilm formation, and outer membrane vesicle (OMV) biogenesis using wild-type (WT) A.

under Acidic Conditions Induces Colistin Resistance through PmrAB Activation and Lipid A Modification.

Colistin is a last-resort antimicrobial agent for treating carbapenem-resistant infections. The activation of PmrAB by several environmental signals induces colistin resistance in Gram-negative bacteria. This study investigated the molecular mechanisms of colistin resistance in under acidic conditions using wild-type (WT) 17978, Δ and Δ mutants, and -complemented strains.

Complete genome sequence of the multidrug-resistant clinical isolate Acinetobacter baumannii KBN10P05679: Insights into antimicrobial resistance genotype and potential virulence traits.

Objectives: Acinetobacter baumannii, a nosocomial pathogen, exhibits multidrug resistance and is a major concern worldwide. We therefore aimed to evaluate the genomic features of the clinical strain A. baumannii KBN10P05679 to elucidate its antibiotic resistance mechanisms and virulence factors.

Complete Genome Sequence of Acinetobacter baumannii Strain KBN10P04593, a Clinical Isolate from South Korea.

Acinetobacter baumannii is an opportunistic nosocomial pathogen that is responsible for various life-threating infections in immunocompromised hosts. We present the complete 3.93-Mb genome sequence of A.

Structure-based discovery of pyrazolamides as novel ERRγ inverse agonists.

Estrogen-related receptor-gamma (ERRγ) is an orphan nuclear receptor with high structural similarity to estrogen receptors (ERα and β). The endogenous ligand of the receptor has yet to be identified. Only two classes of molecules-stilbene (diethylstilbestrol, 4-hydroxytamoxifen, and GSK5182) and flavonol (kaempferol) have been known to modulate the transcriptional activity of the receptor to date.

pKr-2 induces neurodegeneration upregulation of microglial TLR4 in the hippocampus of AD brain.

We recently demonstrated that prothrombin kringle-2 (pKr-2) derived from blood-brain barrier (BBB) disruption could induce hippocampal neurodegeneration and object recognition impairment through neurotoxic inflammatory responses in the five familial Alzheimer's disease mutation (5XFAD) mice. In the present study, we aimed to determine whether pKr-2 induces microglial activation by stimulating toll-like receptor 4 (TLR4) upregulation and examine whether this response contributes to pKr-2-induced neuroinflammatory damage in the hippocampi of mice models. We observed that inflammatory responses induced by pKr-2 administration in the hippocampi of wild-type mice were significantly abrogated in TLR4-deficient mice (TLR4), and caffeine supply or rivaroxaban treatment that inhibits the overexpression of hippocampal pKr-2 reduced TLR4 upregulation in 5XFAD mice, resulting in the inhibition of neuroinflammatory responses.

ECM-targeting bacteria enhance chemotherapeutic drug efficacy by lowering IFP in tumor mouse models.

Bacterial cancer therapies aim to manipulate bacteria to effectively deploy therapeutic payloads to tumors. Attenuated bacteria alone often cannot eradicate solid tumors. Attenuated Salmonella can be engineered to deliver cytotoxic drugs to either trigger an immune response or increase antitumor efficacy when combined with chemotherapeutic drugs.

Complementary Regulation of BfmRS Two-Component and AbaIR Quorum Sensing Systems to Express Virulence-Associated Genes in .

expresses various virulence factors to adapt to hostile environments and infect susceptible hosts. This study investigated the regulatory network of the BfmRS two-component and AbaIR quorum sensing (QS) systems in the expression of virulence-associated genes in ATCC 17978. The Δ mutant exhibited a significant decrease in surface motility, which presumably resulted from the low expression of and - gene cluster.

Engineering of lysin by fusion of antimicrobial peptide (cecropin A) enhances its antibacterial properties against multidrug-resistant .

Most clinical isolates of , a nosocomial pathogen, are multidrug-resistant (MDR), fueling the search for alternative therapies. Bacteriophage-derived endolysins have potent antibacterial activities and are considered as alternatives to antibiotics against infection. Gram-negative bacteria possess outer lipid membrane that prevents direct contact between the endolysins and the cell wall.

Lipocalin2 as a potential antibacterial drug against Acinetobacter baumannii infection.

Available antibiotics to treat Acinetobacter baumannii infection is limited due to increasing resistance and the emergence of multiple drug-resistant strains. Hence, discovering effective agents against A. baumannii to reduce the number of infection-related deaths is imperative.

DksA Modulates Antimicrobial Susceptibility of .

The stringent response regulators, (p)ppGpp and DksA, modulate various genes involved in physiological processes, virulence, and antimicrobial resistance in pathogenic bacteria. This study investigated the role of DksA in the antimicrobial susceptibility of . The ∆ mutant (KM0248D) of ATCC 17978 and its complemented strain (KM0248C) were used, in addition to the ∆ mutant strain (NY0298D) of clinical 1656-2 strain.

LeuO, a LysR-Type Transcriptional Regulator, Is Involved in Biofilm Formation and Virulence of .

is an important nosocomial pathogen that can survive in different environmental conditions and poses a severe threat to public health due to its multidrug resistance properties. Research on transcriptional regulators, which play an essential role in adjusting to new environments, could provide new insights into pathogenesis. LysR-type transcriptional regulators (LTTRs) are structurally conserved among bacterial species and regulate virulence in many pathogens.

Global regulator DksA modulates virulence of .

DksA with (p)ppGpp regulates a wide range of gene transcriptions during the stringent response. The aim of this study was to identify a DksA ortholog in and clarify the roles of DksA in bacterial physiology and virulence. The ∆ mutant and its complemented strains were constructed using ATCC 17978.

Characterization of a Novel Phage ΦAb1656-2 and Its Endolysin with Higher Antimicrobial Activity against Multidrug-Resistant .

is a nosocomial pathogen, which is a problem worldwide due to the emergence of a difficult-to-treat multidrug-resistant (MDRAB). Endolysins are hydrolytic enzymes produced by a bacteriophage that can be used as a potential therapeutic agent for multidrug-resistant bacterial infection in replacing antibiotics. Here, we isolated a novel bacteriophage through prophage induction using mitomycin C from clinical 1656-2.

Perilipin 5 is a novel target of nuclear receptor LRH-1 to regulate hepatic triglycerides metabolism.

Liver receptor homolog-1 (LRH-1) has emerged as a regulator of hepatic glucose, bile acid, and mitochondrial metabolism. However, the functional mechanism underlying the effect of LRH-1 on lipid mobilization has not been addressed. This study investigated the regulatory function of LRH-1 in lipid metabolism in maintaining a normal liver physiological state during fasting.

ppGpp signaling plays a critical role in virulence of .

, a major nosocomial pathogen, survives in diverse hospital environments, and its multidrug resistance is a major concern. The ppGpp-dependent stringent response mediates the reprogramming of genes with diverse functions in several bacteria. We investigated whether ppGpp is involved in pathogenesis by examining biofilm formation, surface motility, adhesion, invasion, and mouse infection studies.

The mechanism of gap creation by a multifunctional nuclease during base excision repair.

During base excision repair, a transient single-stranded DNA (ssDNA) gap is produced at the apurinic/apyrimidinic (AP) site. Exonuclease III, capable of performing both AP endonuclease and exonuclease activity, are responsible for gap creation in bacteria. We used single-molecule fluorescence resonance energy transfer to examine the mechanism of gap creation.