Mesrop Ayrapetyan

University of North Carolina at Chapel Hill | UNC · School of Medicine.

Microbial dormancy is a widespread phenomenon employed by bacteria to evade environmental threats including antibiotics. This intrinsic mechanism of antibiotic tolerance has drawn special attention to the role of dormancy in human disease, particularly in regards to recurrent infections. Two dormancy states, the viable but non-culturable state and...

Dormancy holds a vital role in the ecological dynamics of microorganisms. Specifically, entry into dormancy allows cells to withstand times of stress, while maintaining the potential for reentry into an active existence. The viable but non-culturable (VBNC) state and antibiotic persistence are two well recognized conditions of dormancy evidenced to...

Entry and exit from dormancy are essential survival mechanisms utilized by microorganisms to cope with harsh environments. Many bacteria, including the opportunistic human pathogen Vibrio vulnificus, enter a form of dormancy known as the viable but nonculturable (VBNC) state. VBNC cells can resuscitate when suitable conditions arise, yet the molecu...

The human pathogen, Vibrio vulnificus, is the leading cause of seafood-related deaths in the United States. Strains are genotyped based on alleles that correlates with isolation source, with clinical (C)-genotypes being more often implicated in disease, and environmental (E)-genotypes being more frequently isolated from oysters and estuarine waters...

Bacteria have evolved numerous means of survival in adverse environments with dormancy, as represented by “persistence” and the “viable but nonculturable” (VBNC) state, now recognized to be common modes for such survival. VBNC cells have been defined as cells which, induced by some stress, become nonculturable on media that would normally support t...

A 61-year-old Caucasian man presented with papules on his left forearm and hand three months after liver transplantation: images from physical exam, pathology and microbiology are presented. Skin biopsy confirmed the presence of fungal elements within the hair shaft, which is consistent with Majocchi granuloma, also known as nodular granulomatous p...

Viable but non-culturable (VBNC) cells and antibiotic persisters are well-described phenotypic variants that make up dormant subpopulations allowing bacteria to survive in conditions that are deadly to the rest of their genetically identical lineage. There is growing evidence that these forms of dormancy share molecular mechanisms that govern their...

Entry into and exit from dormancy comprise an essential survival mechanism utilized by microorganisms to cope with harsh environments. Many bacteria enter a form of dormancy known as the viable but nonculturable (VBNC) state, induced by a variety of environmental stresses. VBNC cells can resuscitate when suitable conditions arise, yet the molecular...

Entry and exit from dormancy are essential survival mechanisms utilized by microorganisms to cope with harsh environments. Many bacteria, including the opportunistic human pathogen Vibrio vulnificus, enter a form of dormancy known as the viable but non-culturable (VBNC) state. VBNC cells can resuscitate when suitable conditions arise, yet the molec...

The United States has federal regulations in place to reduce the risk of seafood related infection caused by the estuarine bacteria, Vibrio vulnificus and V. parahaemolyticus. However, data to support regulation development has been generated in a very few specific regions of the nation. More regionally specific data is needed to further understand...

Virulence of the human pathogen, V. vulnificus, is associated with encapsulation, serum complement resistance, and genotype. The C-genotype of this bacterium is correlated (>90%) with virulence and with isolation source (clinical settings). E-genotype strains are highly correlated with environmental isolation (93%) but appear less virulent. In this...

Vibrio vulnificus naturally inhabits a variety of aquatic organisms, including oysters, and is the leading cause of seafood related death in the United States. Strains of this bacterium are genetically classified into environmental (E) and clinical (C) genotypes, which correlate with source of isolation. E-genotypes integrate into marine aggregates...

Abstract Vibrio vulnificus is an estuarine bacterium responsible for 95% of all seafood-related deaths in the United States. Several studies have demonstrated that V. vulnificus infections are enhanced when host iron availability is increased, such as occurs with chronic liver disease. Because of the gender difference seen in these infections, we e...

Marine aggregates are naturally forming conglomerations of larvacean houses, phytoplankton, microbes, and inorganics adhered together by exocellular polymers. In this study, we show in vitro that the bacterial pathogen Vibrio vulnificus can be concentrated into laboratory-generated aggregates from surrounding water. We further show that environment...