Janowiak Lab

Welcome to the Janowiak lab web pages!

The Janowiak lab has two main focuses:

1. Glutathione-dependent pathogenesis of Streptococcus agalactiae (Group B Streptococcus, GBS)

2. Antibiotic discovery and biotherapeutics against multiple drug resistant bacteria 

A summary of each focus is described below:

Glutathione-dependent pathogenesis of Streptococcus agalactiae (Group B Streptococcus, GBS)

Group B Streptococcus (GBS) is a bacterium which normally resides in the healthy women’s vaginal microbiome but can become pathogenic, causing severe infections in newborns. Pregnant mothers are screened for GBS and given antibiotics during pregnancy to remove the bacterium prior to delivery, preventing the infection of the babies. However, many of the babies later develop many inflammation disorders such as asthma and life-threatening allergies, which are now being attributed to the babies not obtaining a healthy microbiome at birth. We are interested in understanding how GBS interacts with its host and environment, both during the pathogenic and non-pathogenic states. We currently have two aims:

1) To evaluate the effect of glutathione synthesis on the immune response of the host. Based on our published results showing that glutathione synthesis contributes to GBS virulence in a mouse model of sepsis, our working hypothesis is that glutathione synthesis promotes inflammatory responses. We employ a combination of cell culture experiments, immunological methods, and good old fashion biochemistry to study these important mechanisms in Group B Streptococcus as well as the host.

2) To determine the role of glutathione in GBS gene expression. Based on our RNA sequencing results, we hypothesize that glutathione regulates multiple genes involved in promoting virulence and evading the immune response. We employ a combination of transcriptomics, metabolomics, and CRISPR-Cas techniques to study these important mechanisms in GBS.

Antibiotic discovery and biotherapeutics against multiple drug resistant bacteria

ESKAPE pathogens are very hard to treat and include six opportunistic bacteria that exhibit multidrug resistance and virulence: Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, and Enterobacter spp. Persistent use of antibiotics has provoked the emergence of multidrug resistant bacteria, which render even the most effective drugs ineffective. It is critical that new antibiotics and biotherapeutics are discovered to help treat infections caused by ESKAPE pathogens. We currently have two aims:

1) Isolate, purify, and identify antibiotic-producing bacteria and antibiotic-producing fungi from various soil samples collected from the environment. This project is spearheaded by my course-based undergraduate research experience (CURE) course in Microbial Ecology and Molecular Biology (BIOL 4160, taught each spring semester). Follow-up, confirmation, and quantification screens against all ESKAPE pathogens is performed in my research lab. Identification involves sequencing 16S genes and ITS regions for the bacteria and fungi, respectively. 

2) Test antibiotic activity of various natural products against ESKAPE pathogens to determine optimal concentrations of active ingredient to inhibit growth and/or kill the bacteria. Our lab performs minimal inhibitory concentration (MIC) assays and minimal bactericidal concentration (MBC) assays of active ingredients of putative antibiotics and other natural products against ESKAPE pathogens. 

For more information about our research, please feel free to contact me at blythe.janowiakmulligan[at]slu.edu, or check out my ResearchGate, Academia.edu, Google Scholar, or LinkedIn pages.

Thanks for visiting!

*Janowiak Lab Banner Image credit: former undergrad researcher, Katie Vaeth (see Almuni lab)

Last updated: June 18, 2024