The oral cavity is a potential reservoir of gram-negative antimicrobial-resistant bacteria, which are correlated with ageing and the number of teeth.

Objectives: The suppression of antimicrobial-resistant bacteria (ARB) is an important issue worldwide. In recent years, the presence of various ARB in the oral cavity has been reported, but the details remain unclear. Therefore, we aimed to isolate ARB from the oral cavity and investigate the factors affecting ARB colonization.

Selection and evaluation of suitable quality control strains for meropenem antimicrobial susceptibility testing through preliminary external quality assessment.

Background: Quality control (QC) of carbapenem susceptibility testing for Gram-negative bacteria faces challenges due to limited measuring ranges and the lack of suitable QC strains. This study aimed to select and evaluate QC strains for meropenem antimicrobial susceptibility testing (AST) through a pilot external quality assessment (EQA).

Methods: Candidate QC strains for meropenem AST were selected based on primary AST data and genomic information from the Japan Antimicrobial Resistant Bacterial Bank.

Ursoricin, a bacteriocin of , has potent activity against methicillin-resistant and vancomycin-resistant enterococci.

Unlabelled: The emergence of drug-resistant bacteria, particularly methicillin-resistant (MRSA) and vancomycin-resistant enterococci (VRE), has increased the need to discover novel antimicrobial agents that are effective against these species. Here, we describe the identification and purification of the mutacin BHT-B-like gene locus and bacteriocin peptide from , which is closely related to ; hence, we named this bacteriocin ursoricin. Ursoricin is a cationic, chromosome-encoded peptide that has potent antimicrobial effects against Gram-positive pathogens, including MRSA and VRE, with minimum inhibitory concentrations in the micromolar range.

Plasmodium berghei proteome changes in response to SSJ-183 treatment.

The benzo[a]phenoxazine derivative, SSJ-183 has shown excellent anti-malarial efficacy and safety. However, its mechanism of action is unclear. We investigated the effect of SSJ-183 on the rodent malarial parasite, Plasmodium berghei.

Selective accumulation of a novel antimalarial rhodacyanine derivative, SSJ-127, in an organelle of Plasmodium berghei.

SSJ-127, a novel antimalarial rhodacyanine derivative, has shown potent antimalarial activity against chloroquine-resistant Plasmodium strains in vitro and subcutaneous administration of SSJ-127 results in a complete cure of a mouse malaria model. SSJ-127 was detected by fluorescence microscopy in the mouse malaria parasites Plasmodium berghei after exposure of infected red blood cells to the compound in vitro and in vivo. Selective accumulation of SSJ-127 in an organelle is observed in all blood stages of live malaria parasites.

Discovery of Novel Benzo[a]phenoxazine SSJ-183 as a Drug Candidate for Malaria.

Malaria is a serious infectious disease caused by protozoan parasites in tropical and subtropical regions. Even inhabitants of temperate zones are exposed to the danger of malaria infection because of travel and global warming. Novel, effective, safe, and inexpensive drugs are required to treat malaria and contribute to the global goal of eradication.

Fluorinated rhodacyanine (SJL-01) possessing high efficacy for visceral leishmaniasis (VL).

Anti-Leishmania in vitro and in vivo activities of various rhodacyanine derivatives have been examined. Among them, the fluorinatied variant SJL-01 (8) showed IC(50) of 0.011 microM against Leishmania donovani strain MHOM/ET/67/L82 (selective index of >15000) and 95-97% inhibition against L.

Pharmacodynamics and pharmacokinetics studies of phenoxazinium derivatives for antimalarial agent.

In vivo antimalarial drug candidates screening test was carried out on a series of water-soluble 3,7-bis(dialkylamino)phenoxazin-5-ium derivatives. Among them, 3-(diethylamino)-7-(piperidin-1-yl)phenoxazin-5-ium chloride (SSJ-206) showing highest efficacy was chosen for further pharmcodynamics and pharmacokinetics study. It was supported from these data that the phenoxazinium salts, SSJ-206, would be one of hopeful candidates as an oral antimalarial drug.

Synthesis and in vitro antiprotozoal activities of water-soluble, inexpensive 3,7-bis(dialkylamino)phenoxazin-5-ium derivatives.

3,7-Bis(dialkylamino)phenoxazinium salts were synthesized and evaluated for in vitro activities against Plasmodium falciparum, Trypanosoma cruzi, T. brucei rhodesiense, and Leishmania donovani. Notably, the compounds showed potent antiprotozoal activities, especially against P.