Project Title

Does Alcaligenes inhibit other Staphylococcal species?

Authors' Affiliations

Department of Health Sciences, College of Public Health, East Tennessee State University, Johnson City, TN

Location

Ballroom

Start Date

4-5-2018 8:00 AM

End Date

4-5-2018 12:00 PM

Poster Number

40

Name of Project's Faculty Sponsor

Sean Fox

Faculty Sponsor's Department

Health Sciences

Type

Poster: Competitive

Classification of First Author

Undergraduate Student

Project's Category

Biomedical and Health Sciences

Abstract Text

Members of the Staphylococcus genus are a major health issue in the clinical environment and can cause a wide range of disease in humans. However, this genus is also found as a part of the normal flora in humans, usually on the skin, nasal cavities, or on the linings of the throat. Normal flora members of the Staphylococcus genus become an opportunistic infection when there is breach in the physical barriers or the immune status of the human host. Another challenge with the Staphylococcus genus is the increase in drug resistant strains, such as Methicillin resistant Staphylococcus aureus (MRSA), making simple infections difficult to treat and leading to severe toxic shock or even death. Recently, there have been numerous studies demonstrating normal flora bacterial interactions inhibiting bacteria that are potentially harmful to humans. Our research lab has previously demonstrated that the benign bacterium Alcaligenes faecalis has inhibitory effects against Staphylococcus aureus. In the present study, we wanted to explore: 1) if the inhibitory effect of A. faecalis would translate to other Staphylococcus species (S. capitis, S. saprophyticus, and S. epidermidis); 2) if this inhibitory effect was found in other Alcaligenes species (A. viscolactis). To determine this possible interactions, two parallel experimental projects were undertaken. A. faecalis and A. viscolactis were tested for their interactions with Staphylococcus species on both agar and liquid medium. For agar medium analysis, Staphylococcus lawns were grown on agar plates and either Alcaligenes cells, heat killed Alcaligenes, or Alcaligenes cell free supernatant were spotted onto the lawns and observed and scored for zones of inhibition (ZOI). It was demonstrated live cells of both A. faecalis and A. viscolactis were needed to produce ZOI on Staphylococcus lawns and that all Staphylococcus species were inhibited. For liquid medium analysis, Staphylococcus species were either inoculated alone (control) or in a co-culture with Alcaligenes, serially diluted, and colony forming units (CFU) were enumerated. Both A. faecalis and A. viscolactis inhibited all Staphylococcus species in liquid culture. Based on the results from these experiments, it is our conclusion that: 1) Alcaligenes faecalis and Alcaligenes viscolactis both possess the ability to inhibit Staphylococcus growth; 2) all Staphylococcus species are inhibited by Alcaligenes, but at varying levels. The exact mechanism of how Alcaligenes can inhibit Staphylococcus species is unknown, which will require further studies to analyze and understand the exact mechanism in order to create effective therapeutic targets to combat these increasingly resistant strains of Staphylococcus.

This document is currently not available here.

Share

COinS
 
Apr 5th, 8:00 AM Apr 5th, 12:00 PM

Does Alcaligenes inhibit other Staphylococcal species?

Ballroom

Members of the Staphylococcus genus are a major health issue in the clinical environment and can cause a wide range of disease in humans. However, this genus is also found as a part of the normal flora in humans, usually on the skin, nasal cavities, or on the linings of the throat. Normal flora members of the Staphylococcus genus become an opportunistic infection when there is breach in the physical barriers or the immune status of the human host. Another challenge with the Staphylococcus genus is the increase in drug resistant strains, such as Methicillin resistant Staphylococcus aureus (MRSA), making simple infections difficult to treat and leading to severe toxic shock or even death. Recently, there have been numerous studies demonstrating normal flora bacterial interactions inhibiting bacteria that are potentially harmful to humans. Our research lab has previously demonstrated that the benign bacterium Alcaligenes faecalis has inhibitory effects against Staphylococcus aureus. In the present study, we wanted to explore: 1) if the inhibitory effect of A. faecalis would translate to other Staphylococcus species (S. capitis, S. saprophyticus, and S. epidermidis); 2) if this inhibitory effect was found in other Alcaligenes species (A. viscolactis). To determine this possible interactions, two parallel experimental projects were undertaken. A. faecalis and A. viscolactis were tested for their interactions with Staphylococcus species on both agar and liquid medium. For agar medium analysis, Staphylococcus lawns were grown on agar plates and either Alcaligenes cells, heat killed Alcaligenes, or Alcaligenes cell free supernatant were spotted onto the lawns and observed and scored for zones of inhibition (ZOI). It was demonstrated live cells of both A. faecalis and A. viscolactis were needed to produce ZOI on Staphylococcus lawns and that all Staphylococcus species were inhibited. For liquid medium analysis, Staphylococcus species were either inoculated alone (control) or in a co-culture with Alcaligenes, serially diluted, and colony forming units (CFU) were enumerated. Both A. faecalis and A. viscolactis inhibited all Staphylococcus species in liquid culture. Based on the results from these experiments, it is our conclusion that: 1) Alcaligenes faecalis and Alcaligenes viscolactis both possess the ability to inhibit Staphylococcus growth; 2) all Staphylococcus species are inhibited by Alcaligenes, but at varying levels. The exact mechanism of how Alcaligenes can inhibit Staphylococcus species is unknown, which will require further studies to analyze and understand the exact mechanism in order to create effective therapeutic targets to combat these increasingly resistant strains of Staphylococcus.