Publications by authors named "Binayak Rimal"

, a leading non-tuberculous mycobacterium (NTM) pathogen, causes chronic pulmonary infections, particularly in individuals with underlying lung conditions or immunosuppression. Current treatments involve prolonged multi-drug regimens with poor outcomes and significant side effects, highlighting the urgent need for improved therapies. Using a BALB/c mouse model of chronic pulmonary disease, we evaluated the efficacy of individual antibiotics-clarithromycin, clofazimine, and rifabutin-and combination regimens including clarithromycin+bedaquiline and clarithromycin+clofazimine+bedaquiline.

View Article and Find Full Text PDF
Article Synopsis
  • The text discusses an opportunistic pathogen that commonly affects individuals with lung issues and weakened immune systems, noting that there are no FDA-approved treatments and a high failure rate for current options.
  • It introduces MRX-6038, an intravenous oxaborole that is effective against this pathogen, and presents MRX-5, its oral prodrug, as a subject of study.
  • Results from the study demonstrated that MRX-5 showed effective results in a mouse model, with doses of 15 and 45 mg/kg performing similarly to standard treatments, indicating potential for clinical trials.
View Article and Find Full Text PDF

Understanding the dynamics of biofilm formation and its elemental composition is crucial for developing effective strategies against biofilm-associated infections. In this study, we employed scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDS) to investigate the morphological changes and elemental compositions of biofilms. SEM images revealed distinct stages of biofilm development, from initial aggregation to the formation of mature and aged biofilms.

View Article and Find Full Text PDF

( or ) is a fast-growing mycobacterium that is ubiquitous in the environment and can cause opportunistic disease in people with lung comorbidity and immunodeficiency. There are no Food and Drug Administration-approved drugs for this disease, and repurposed antibiotics have a poor microbiological response. To address the need for effective new antibiotics, we determined the efficacy of epetraborole (EBO) against three clinical isolates in a mouse model of lung infection.

View Article and Find Full Text PDF

Treatment outcomes for (, also known as ) disease are still unsatisfactory, mainly due to issues with drug toxicity, tolerability, and efficacy. Treating disease is challenging due to its high baseline antibiotic resistance, initial requirement for intravenous therapy, and poor medication tolerance. Omadacycline, a new tetracycline, is active against .

View Article and Find Full Text PDF

Mycobacteroides abscessus (Mab, also known as Mycobacterium abscessus) causes opportunistic pulmonary and soft tissue infections that are difficult to cure with existing treatments. Omadacycline, a new tetracycline antibiotic, exhibits potent in vitro and in vivo activity against Mab. As regimens containing multiple antibiotics are required to produce a durable cure for Mab disease, we assessed efficacies of three three-drug combinations in a pre-clinical mouse model of pulmonary Mab disease to identify companion drugs with which omadacycline exhibits the highest efficacy.

View Article and Find Full Text PDF

Daptomycin is a cyclic lipodepsipeptide antibiotic reserved for the treatment of serious infections by multidrug-resistant Gram-positive pathogens. Its mode of action is considered to be multifaceted, encompassing the targeting and depolarization of bacterial cell membranes, alongside the inhibition of cell wall biosynthesis. To characterize the daptomycin mode of action, N cross-polarization at magic-angle spinning NMR measurements were performed on intact whole cells of Staphylococcus aureus grown in the presence of a sub-inhibitory concentration of daptomycin in a chemically defined media containing L-[ϵ-N]Lys.

View Article and Find Full Text PDF

Mycobacteroides abscessus is an opportunistic pathogen in people with structural lung conditions such as bronchiectasis, chronic obstructive pulmonary disease, and cystic fibrosis. Pulmonary M. abscessus infection causes progressive symptomatic and functional decline as well as diminished lung function and is often incurable with existing antibiotics.

View Article and Find Full Text PDF

The benzothiazole amide CRS0393 demonstrated excellent in vitro activity against nontuberculous mycobacteria (NTM), including M. abscessus isolates from cystic fibrosis (CF) patients, with minimum inhibitory concentrations (MICs) of ≤0.03-0.

View Article and Find Full Text PDF

Peptidoglycan (PG) is the exoskeleton of bacterial cells and is required for their viability, growth, and cell division. Unlike most bacteria, mycobacteria possess an atypical PG characterized by a high degree of unique linkages and chemical modifications which most likely serve as important determinants of virulence and pathogenesis in mycobacterial diseases. Despite this important role, the chemical composition and molecular architecture of mycobacterial PG have yet to be fully determined.

View Article and Find Full Text PDF

Mycobacteroides abscessus () is an emerging environmental microbe that causes chronic lung disease in patients with compromised lung function such as cystic fibrosis and bronchiectasis. It is intrinsically resistant to most antibiotics, therefore there are only few antibiotics that can be repurposed to treat disease. Although current recommendations require daily intake of multiple antibiotics for more than a year, cure rate is low and often associated with significant adverse events.

View Article and Find Full Text PDF

Culex pipiens is a major carrier of the West Nile Virus, the leading cause of mosquito-borne disease in the continental United States. Cx. pipiens survive overwinter through diapause which is an important survival strategy that is under the control of insulin signaling and Foxo by regulating energy metabolism.

View Article and Find Full Text PDF
Article Synopsis
  • Peptidoglycan (PG) is a crucial component of bacterial cell walls, providing strength and structure, but its remodeling processes and the effects of these changes on bacterial biology are not well understood.
  • Recent advancements have allowed the development of new probes that specifically target L,D-transpeptidases (Ldts), enzymes that play a key role in PG cross-linking, which is important for maintaining cell wall integrity and influencing antibiotic efficacy.
  • This research demonstrates that small modifications to PG can influence Ldt activity and cross-linking, paving the way for a better understanding of how various cross-linking processes work together to shape PG structure and function.
View Article and Find Full Text PDF

Carboxy-terminal processing proteases (CTPs) occur in all three domains of life. In bacteria, some of them have been associated with virulence. However, the precise roles of bacterial CTPs are poorly understood, and few direct proteolytic substrates have been identified.

View Article and Find Full Text PDF

Resuscitation-promoting factors (Rpfs) have previously been shown to act as growth-stimulatory molecules via their lysozyme-like activity on peptidoglycan in the bacterial cell wall. In this study, we investigated the ability of strains lacking genes to form biofilms and tested their susceptibilities to cell wall-targeting agents. contains four distinct homologues, namely, MSMEG_5700 (), MSMEG_5439 (), MSMEG_4640 (), and MSMEG_4643 ().

View Article and Find Full Text PDF

Staphylococcus aureus biofilms pose a serious clinical threat as reservoirs for persistent infections. Despite this clinical significance, the composition and mechanism of formation of S. aureus biofilms are unknown.

View Article and Find Full Text PDF

Mycobacteria possess a multi-layered cell wall that requires extensive remodelling during cell division. We investigated the role of an amidase_3 domain-containing N-acetylmuramyl-L-alanine amidase, a peptidoglycan remodelling enzyme implicated in cell division. We demonstrated that deletion of MSMEG_6281 (Ami1) in Mycobacterium smegmatis resulted in the formation of cellular chains, illustrative of cells that were unable to complete division.

View Article and Find Full Text PDF