Gram Negatives

Universal and early recognition of pathogens occurs through recognition of evolutionarily conserved pathogen associated molecular patterns (PAMPs) by innate immune receptors and the consequent secretion of cytokines and chemokines. The intrinsic complexity of innate immune signaling and associated signal transduction challenges our ability to obtain physiologically relevant, reproducible and accurate data from experimental systems. One of the reasons for the discrepancy in observed data is the choice of measurement strategy...

The application of transition metal complexes for antimicrobial photodynamic therapy (PDT) has emerged as an attractive alternative in mitigating a broad range of bacterial pathogens, including multidrug-resistant pathogens. In view of their photostability, long excited-state lifetimes, and tunable emission properties, transition metal complexes also contribute as bioimaging agents. In the present work, we designed mono and trinuclear cyclometalated iridium(III) complexes to explore their imaging application and antibacterial potential...

The discovery of safe and efficient inhibitors against efflux pumps as well as metallo-β-lactamases (MBL) is one of the main challenges in the development of multidrug-resistant (MDR) reversal agents which can be utilized in the treatment of carbapenem-resistant Gram-negative bacteria. In this study, we have identified that introduction of an ethylene-linked sterically demanding group at the 3-OH position of the previously reported MDR reversal agent di-F-Q endows the resulting compounds with hereto unknown multitarget inhibitory activity against both efflux pumps and broad-spectrum β-lactamases including difficult-to-inhibit MBLs...

A Gram-stain-negative, rod-shaped, non-motile, catalase-positive, denitrifying bacterium, designated strain Y-1T , was isolated from an aeration tank of a sewage treatment plant in China and characterized using polyphasic taxonomic approaches. Strain Y-1T could grow at 10-37 °C (optimum 25 °C), at pH 5.0-10.0 (optimum 7.0) and in the presence of 0-3.0% (w/v) NaCl (optimum 0.5%). The phylogenetic tree based on the 16S rRNA gene sequences revealed that strain Y-1T was a member of genus Diaphorobacter, and showed the highest sequence similarities with Diaphorobacter oryzae RF3T (97...

A Gram-negative, motile, rod-shaped bacterial strain, CA-0114T , was isolated from the midgut of a western honey bee, Apis mellifera . The isolate exhibited ≤96.43 % 16S rRNA gene sequence identity (1540 bp) to members of the families Enterobacteriaceae and Erwiniaceae . Phylogenetic trees based on genome blast distance phylogeny and concatenated protein sequences encoded by conserved genes atpD , fusA, gyrB , infB , leuS , pyrG and rpoB separated the isolate from other genera forming a distinct lineage in the Enterobacteriaceae ...

Two Gram-negative, aerobic, rod-shaped bacterial strains, 7MK25T and 6Y81T , were isolated from forest soil of Dinghushan Biosphere Reserve, Guangdong Province, PR China. Based on the results of 16S rRNA gene sequence analysis, strain 7MK25T showed the highest similarity (93.6 %) to Methyloferula stellata AR4T , followed by Bosea thiooxidans DSM 9653T (93.3 %). Strain 6Y81T had the highest similarity of 97.9 % to Lichenibacterium minor RmlP026T , followed by Lichenibacterium ramalinae RmlP001T (97...

UNLABELLED: Antimicrobial resistance (AMR) poses a significant worldwide public health crisis that continues to threaten our ability to successfully treat bacterial infections. With the decline in effectiveness of conventional antimicrobial therapies and the lack of new antibiotic pipelines, there is a renewed interest in exploring the potential of metal-based antimicrobial compounds. Antimony-based compounds with a long history of use in medicine have re-emerged as potential antimicrobial agents...

Responsive nanomaterials hold significant promise in the treatment of bacterial infections by recognizing internal or external stimuli to achieve stimuli-responsive behavior. In this study, we present an enzyme-responsive polyelectrolyte complex micelles (PTPMN) with α-helical cationic polypeptide as a coacervate-core for the treatment of Escherichia coli ( E. coli ) infection. The complex was constructed through electrostatic interaction between cationic poly(glutamic acid) derivatives and phosphorylation-modified poly(ethylene glycol)- b -poly(tyrosine) (PEG- b -PPTyr) by directly dissolving them in aqueous solution...

Helicobacter is a genus of spiral-shaped Gram-negative enterohepatic bacteria whose members are capable of causing bacteremia in humans. One of the poorly studied members of this genus is the bacterium Helicobacter cinaedi . This microorganism was first isolated from human fecal samples in 1984. Although it was long considered to be associated with only immunocompromised patients, more evidence in recent years has implicated H. cinaedi in causing serious pathologies in immunocompetent populations. In addition, H...

Fire blight, caused by the Gram-negative bacterium Erwinia amylovora , poses a substantial threat to pome fruit production worldwide. Despite existing control strategies, a pressing need remains for sustainable and environmentally friendly fire blight management. Myxobacteria, renowned for their predatory behavior and potent enzymes, emerge as a groundbreaking biocontrol approach with significant potential. Here, we report the biocontrol potential of a novel Myxococcus fulvus WCH05, against E. amylovora . Using various in vitro and planta assays, we demonstrated the multifaceted biocontrol abilities of strain WCH05...

BACKGROUND: Bacteria-based cancer therapy have demonstrated innovative strategies to combat tumors. Recent studies have focused on gram-negative bacterial outer membrane vesicles (OMVs) as a novel cancer immunotherapy strategy due to its intrinsic properties as a versatile carrier. METHOD: Here, we developed an Human Papillomavirus (HPV)-associated E7 antigen displaying Salmonella-derived OMV vaccine, utilizing a Poly(L-arginine) cell penetrating peptide (CPP) to enhance HPV16 E7 (aa49-67) H-2 Db and OMV affinity, termed SOMV-9RE7...

Carbapenem-resistant Acinetobacter baumannii infections have limited treatment options. Synthesis, transport and placement of lipopolysaccharide or lipooligosaccharide (LOS) in the outer membrane of Gram-negative bacteria are important for bacterial virulence and survival. Here we describe the cerastecins, inhibitors of the A. baumannii transporter MsbA, an LOS flippase. These molecules are potent and bactericidal against A. baumannii, including clinical carbapenem-resistant Acinetobacter baumannii isolates...

Highly solid-state fluorescent dyes based on phenothiazine bearing sulfa-drug derivatives were successfully prepared and fully characterized by NMR, mass spectra, and elemental analysis. The prepared phenothiazine dyes bearing sulfadiazine and sulfathiazole 4-(((10-hexyl-10 H-phenothiazin-3-yl)methylene)amino)-N-(pyrimidin-2yl) benzenesulfonamide (PTZ-1) and 4-(((10-hexyl-10 H-phenothiazin-3-yl) methylene) amino)-N-(thiazol-2-yl)benzenesulfonamide (PTZ-2), showed strong emission in polycrystalline form, and significant emission in solution was observed...

OBJECTIVE: To identify the profile of organisms causing neonatal sepsis and their antibiotic susceptibility pattern in recent years. METHODS: In this prospective study, authors included neonates with blood culture proven sepsis. Antibiotic resistance patterns that were identified were extended spectrum β-lactamase, AmpC β-lactamase and possible carbapenamase producer. Xpert CARBA-R test was performed to identify genes causing carbapenem resistance. RESULTS: There were 210 neonates with 216 episodes of blood culture proven sepsis...

A Gram-stain-negative, aerobic, rod-shaped, motile, flagellated bacterial strain, designated as CAU 1639T , was isolated from the tidal flat sediment on the Yellow Sea in the Republic of Korea. Growth of the isolate was observed at 20-37 °C, at pH 5.0-10.5 and with 0-7% (w/v) NaCl. The genomic DNA G + C content was 60.8%. Phylogenetic analysis, grounded on 16S rRNA gene sequencing, revealed that strain CAU 1639T was closely related to species within the genus Roseibium. It shared the highest similarity with Roseibium album CECT 5095T , followed by Roseibium aggregatum IAM 12614T and Roseibium salinum Cs25T , with 16S rRNA gene sequence similarity ranging from 98...

Silver/polymeric vesicle composite nanoparticles with good antibacterial properties were fabricated in this study. Silver nanoparticles (AgNPs) were prepared in situ on cross-linked vesicle membranes through the reduction of silver nitrate (AgNO3 ) using polyvinylpyrrolidone (PVP) via coordination bonding between the Ag+ ions and the nitrogen atoms on the vesicles. X-ray diffraction (XRD), ultraviolet-visible spectroscopy (UV-vis), and transmission electron microscopy (TEM) analyses confirmed the formation of AgNPs on the vesicles...

EVER206 (also known as SPR206) is a novel polymyxin analog that has shown in vitro potency and in vivo efficacy against multidrug-resistant (MDR) Gram-negative pathogens. This randomized, double-blinded, placebo-controlled, Phase I study evaluated the safety, tolerability, and pharmacokinetics of EVER206 in healthy Chinese subjects. After single administration of 50-300 mg EVER206, the Cmax ranged from 3.94 to 25.82 mg/L, and the AUC0-inf ranged from 12.42 to 101.67 h·mg/L. The plasma exposure displayed a linear relationship with the dose administered...

The absence of better biomarkers currently limits early diagnosis and treatment of triple-negative breast cancer (TNBC). Our previously published study reported that the cyclic-peptide SD01 exhibited specific binding to EphA2 (Ephrin type-A receptor 2) on TNBC. To develop a novel PET imaging agent, we prepared gallium-68 (68 Ga) labeled-DOTA-SD01 and evaluated its specificity and effectiveness through micro PET/CT imaging in a TNBC-bearing mouse model. SD01 and a control linear peptide YSA were conjugated to DOTA and subsequently labeled with 68 Ga, obtaining 68 Ga-DOTA-SD01 and 68 Ga-DOTA-YSA...

Proteus mirabilis is a Gram-negative bacterium with exclusive molecular and biological features. It is a versatile pathogen acclaimed for its distinct urease production, swarming behavior, and rapid multicellular activity. Clinically, P. mirabilis is a frequent pathogen of the human urinary system where it causes urinary tract infections (UTIs) and catheter-associated urinary tract infections (CAUTIs). This review explores the epidemiology, risk factors, clinical manifestations, and treatment of P. mirabilis infections, emphasizing its association with UTIs...

Pseudomonas aeruginosa , a Gram-negative bacterium, is recognized for its adaptability and opportunistic nature. It poses a substantial challenge in clinical settings due to its complicated antibiotic resistance mechanisms, biofilm formation, and capacity for persistent infections in both animal and human hosts. Recent studies revealed a potential zoonotic transmission of P. aeruginosa between animals, the environment, and human populations which highlights awareness of this microbe. Implementation of the One Health approach, which underscores the connection between human, animal, and environmental health, we aim to offer a comprehensive perspective on the current landscape of P...