Lab News

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Spring has sprung and we are proud to announce that Dr. Xiomarie Alejandro Navarreto received the prestigious UIC fellowship known as Institutional Research and Academic Career Development Award (IRACDA), following in the footsteps of our former lab member and Xiomarie’s best friend, Dr. Diandra Vaval Taylor. The fellowship is designed to provide Xiomarie with rigorous training in both teaching and academic research. The award comes with a bittersweet realization that she will leave us in August to begin her postdoctoral research under the mentorship of Dr. Eric Stabb in the Department of Biological Sciences. Fortunately, she doesn’t move far, just upstairs, so we can still meet her!

A double distinction was just bestowed on Xiomarie, who won Travel Award to attend the ASM Microbe 2024 conference in Atlanta, Georgia, which will take place on June 13-17. But that's not all! Her abstract was selected for a prestigious Poster Spotlight Presentation Talk. This means that she will have to discuss her research in front of the entire conference audience, with a microphone, a situation that may generate some stress in others, but definitely not in Xiomarie! She is a great presenter!

The latest manuscript by Xiomarie and Nancy, titled "Revisiting old friends: updates on the role of two-component signaling systems in Listeria monocytogenes survival and pathogenesis" has just been accepted for the publication in the Infection and Immunity journal. Woo hoo! Congratulations!

Wishing you both a few extra hours of sleep and all the joy of a new baby!

Congratulations to Dee Dee! She won 1st place for her poster presentation during the 14th Annual COP Research Day, receiving American Association of Pharmaceutical Scientists Student Chapter Choice Award!

Congratulations to Dee Dee who on November 6, 2023, passed her preliminary examination for Doctor of Philosophy with flying colors!

Last weekend our whole lab attended 2023 Midwest Microbial Pathogenesis Conference that was held in downtown Chicago in Rubloff building at Northwestern Pritzker School of Law. The Federle, the Palmer, and the Behnsen Labs were there too. We also met Laty Cahoon, a former postdoctoral trainee of Nancy, and her newly established lab at the University of Pittsburgh in Pittsburgh, Pennsylvania. The conference was very interesting and the talks by JD Sauer of University of Wisconsin-Madison "Life on the inside: adaptations of a cytosolic pathogen" and that by Sam Light of University of Chicago "Defining versatile microbial metabolisms that contextualize the gut ecosystem" closely touched the subjects of cysteine phosphorylation and carbon catabolite repression (CCR) studied by Jerry Woo. The keynote talk by Eric Skaar of Vanderbilt University "The battle for metal at the host-pathogen interface" was close to Adriana's heart who works on heme acquisition in Listeria monocytogenes. All of us presented posters, too. Even though the conference this year took place in our hometown and did not involve travel to any new destinations, we thoroughly enjoyed it. Afterwards, on Sunday afternoon Nancy took us to lunch at D4 Irish Pub & Cafe. Both, the conference and the lunch were delightful!

Congratulations are in order for Xiomarie and Xavier who officially said "I do" on October 6th 2023! We wish you the years ahead to be filled with love and joy as you embark on this new journey together. Cheers!

For the first time since 2015, the MBRB Building Research Day was revived by Dr. Max Svetlov and took place last Friday, September 29, 2023. The goal of this event was to meet, share research, and connect with all our colleagues working in the MBRB Building. The building is home for research activities of at least four departments, including the 3rd floor PSCI department, the Biochemistry and Molecular Genetics department on the 1st and 2nd floors, and the Departments of Biological Sciences and the Molecular Cell Biology on the 4th floor. The event included poster presentations on all four floors followed by the poster competition, food, and games afterwards that lasted late into the midnight (as only heard by your reporter, as she was in bed by 9 pm). The MBRB Day proved to be a great fun for everyone! Warm thanks to the organizers!

Freitag Lab dominated this year's Cold Spring Harbor Laboratory Conference with four Listeria monocytogenes poster presentations by Adriana, Andrea, Dee Dee, and Prof. Freitag. Weather cooperated and five-day conference full of spectacular talks and scientific presentations ended with a lobster banquet and a beautiful concert by two internationally renowned virtuosi - cellist Adrian Daurov and pianist Spencer Myer who played the two cello/piano sonatas by Johannes Brahms to our all delight.

Last week, Jerry Woo presented a poster titled "A Peptide Motif in Two Distinct Gram-positive Virulence Regulators Links Carbon Catabolite Repression to Virulence Gene Expression" at the 2023 Phage meeting taking place at the historic Memorial Union at the University of Wisconsin-Madison, on the beautiful shore of Lake Mendota. Jerry's findings relate to the master transcriptional regulator of virulence in S. pyogenes, called Mga. Until now, the C-terminus of Mga was believed to be a mere scaffold for Mga oligomerization; however, Jerry's research suggests that the C-terminus of Mga is crucial for the process of Carbon Catabolite Repression (CCR), through phosphorylation of a novel motif YCFF present at the Mga C-terminus. Jerry identified a similar YCIF motif in PrfA, the master regulator of virulence in L. monocytogenes. Based on the function of Mga phosphoablative and phosphomimetic mutants in ManL-deletion background, it is likely that cysteines present in the novel motifs of Mga and PrfA are phosphorylated in a carbohydrate-dependent manner by ManL protein. Jerry's overall feelings about this year's Phage meeting was that Gram positive bacteria research was under-represented at the conference. In that case, good that he attended and represented all of us who tirelessly study the Gram-positive bugs! Cheers to Jerry! To read his abstract, click here

Evelyn Qi (aka SURF'er), a winner of the Summer Undergraduate Research Fellowship at UIC College of Pharmacy, presented her poster titled "Defining the Key Amino Acid Residues of the pPplA Phermone that Contributes to Listeria monocytogenes Intracellular Infection" at the Summer 2023 Undergraduate Research Mini Symposium. Evelyn conducted 10-weeks of research in the Freitag lab during this summer under the wing of Dee Dee Aman. Together, they performed functional assays to determine which of the 20 key amino acids in pPplA contributes most to Listeria's virulence. We definitely will miss Evelyn's great work ethic and fun presence in our lab!

We are happy to announce that on July 13, 2023, Xiomarie Alejandro Navarreto defended with a great success her thesis titled "Characterization of Listeria monocytogenes operon required for stress resistance and virulence". With this, she completed all requirements and officially became Doctor of Philosophy in Microbiology. Kudos to her!!! To read abstract of her thesis, please click here.

We are so proud of you and your graduation from UIC College of Medicine! May your graduate degree open a lot of doors and bring you fantastic opportunities for the future! We love you as our lab mate, teacher and friend! Despite occasional setbacks you persisted with your plans and became better because of it! Caps off to you, you deserve it!!!

Congratulations to Diandra M. Vaval Taylor, Bobbi Xayarath, and Nancy E. Freitag, whose research paper "Two Permeases Associated with the Multifunctional CtaP Cysteine Transport System in Listeria monocytogenes Play Distinct Roles in Pathogenesis" was published in Microbiol Spectrum 2023 Jun 15;11(3). The primary author, Diandra Vaval Taylor describes here two membrane-bound permeases CtpP1 and CtpP2, related to CtaP protein associated with cysteine transport. She found that CtpP1 and CtpP2 have functions that are nonoverlapping with CtaP, and are required for bacterial growth in the presence of low concentrations of cysteine and for virulence in mouse infection models. Interesting findings!!! Click here for a link the the publication

Two super talented undergraduate students, Xhoana Bendaj, pursuing the Bachelor of Science in Pharmaceutical Sciences (BSPS), and Mercy Kremer going after the Bachelor of Science in Biochemistry, both spend their class-free time in Freitag Lab this semester. Their dedication and hard work drive the progress of two important projects in the lab: Rgg 2/3 quorum sensing and heme-uptake mechanisms in L. monocytogenes, respectively. We're glad they are here!

We are proud to announce that Diandra M. Vaval Taylor defended with a great fanfare her doctoral thesis on April 22, 2022!!! She is graduating with Ph.D. degree later this spring. For a newly minted Doctor of Microbiology, we wish lots of success in the future and many great opportunities that PhD can provide! Although Diandra's thesis is under embargo for two years at the UIC Library, you can read the abstract of her thesis: "Two Roles, One Pheromone: A Listeria Peptide that Contributes to Both Vacuole Escape and Viability" by clicking here. Way to go, Diandra!!!

SACNAS, also known as National Diversity in STEM conference is a gathering which serves to equip, empower, and energize participants for their academic and professional paths in STEM. It consists of inclusive and welcoming community of peers, mentors, and role models from multicultural backgrounds and traditions.

Warmest wishes to Dee Dee and Casey who tied the knot on October 22, 2022!

Leaves are turning yellow and falling from the trees, a sure sign that fall is here and with it, International Conference on Gram-Positive Pathogens (ICG+P). Held in Omaha, Nebraska, every two years, it was the first post-Covid meeting to which we all went (except for Xiomarie who was too busy with finishing up her project). Conference was co-chaired by Francis Alonzo and lasted three days, during which Diandra presented her talk titled "Two roles, one pheromone: a Listeria monocytogenes peptide pheromone that contributes to both vacuole escape and viability". The talk proved to be very popular especially among Listeria researchers who felt a bit underrepresented in midst of all the Staph and Strep presentations. In addition, Jerry and Sam presented their newest findings in the posters, receiving a wide and receptive audience. Sam's poster was titled "Post-transcriptional regulation of virulence factor InlB leads to increased vertical transmission of Listeria monocytogenes", while Jerry presented poster about "A peptide motif in two distinct Gram-positive virulence regulators that links carbon catabolite repression to virulence gene expression". Popular among all the conference goers was a daily Happy Hour with free drinks for anyone staying at the Embassy Suits. Hotel was located within the old market of downtown Omaha, within twenty minutes' walk to numerous attractions, including the spectacular Henry Doorly Zoo & Aquarium where we spend several hours of our first day. The weather cooperated too, with a balmy seventies and sunshine every day. The creative atmosphere at the ICG+P conference among the top world microbiologists unexpectedly has awaken business acumen in all of us. This led to a conception of an interesting business idea, of which I shall remain silent for now. In summary, ICG+P was a success and we are all grateful to Nancy for taking us there!

At the beginning of October all the members of Freitag Lab (except Jerry, who stayed at home with his beautiful son Connor) attended Midwestern Conference on Microbial Pathogens in Madison, WI. It just happened that the conference took place on Saturday, Oct 1st, a day when University of Wisconsin Badgers were to contend with University of Illinois Fighting Illini. Since the early morning, the celebrations began in anticipation of the game. Everywhere one could see students clad in red or red/white striped clothes to show support for their team. In the end however, brave Illini beat Badgers, which did little to discourage UW students from continuing to party until small hours of the night. One can only imagine the extent of celebrations that would take place if UW actually won. Anyway, older, and wiser, we were all focused on science talks and posters at the conference, especially enjoying the Keynote Address given by NYU faculty, Victor Torres, PhD. Prof. Torres emphasized with his data how different the strains of bacteria studied in the lab are from the current clinical strains that cause infections in hospitals. This is something that our lab already tries to address by using cardiac strains of Listeria isolated from the patients. The conference gave us an opportunity to meet face-to-face with our collaborators, including Laty Cahoon and her lab. In summary, the conference was a great success!

Warmest congratulations to L. A. Cahoon, X. Alejandro-Navarreto, A. N. Gururaja, S. H. Light, F. Alonzo, W. F. Anderson, and N. E. Freitag on the acceptance of their latest manuscript in Molecular Microbiology journal! The team characterized a two-component system PieRS, whose regulon contains PrsA1 and PrsA2 chaperones, among others. PieRS regulated gene products are required for resistance to ethanol exposure and survival of Listeria in a GI tract. PrsA1, which so far puzzled by lack of the defined function, was found to contribute to the survival of L. m in the intestines of a host. Good teamwork!

Congrats and best wishes to Andrea who passed qualifying exam on Thursday, June 21, 2022, and is one step closer to getting her doctorate!

After excited anticipation, the first COP Lablympics took place on Friday July 8th, 2022, in front of MBRB building. The competition was dominated by members of Murphy Lab, who claimed the gold medal, followed by Moore Lab with silver and Zhao Lab with bronze. The record participation in the games just proved how talented the COP graduate students are in jostling a whole array of laboratory skills. Members of the Freitag lab, including Jerry, Dee Dee, Sam, Andrea and Xiomarie contended in the games, with Dee Dee and Jerry scoring particularly high in cookie eating competition in which cookies were placed on the forehead and had to end up in the mouth of participants without the help of hands. Sam proved his excellence in spinning and levitating Falcon tubes. The success of this year’s Lablympics suggests that the games are likely to become an annual event and that the time to start preparing for the next year competition is NOW!

Prof. Freitag received an NIH R01 grant from National Institute of Allergy and Infectious Diseases titled "Deciphering mechanisms of Listeria placental-fetal invasion."

Three first year MSTP students: Jacqueline Kieltyka, Edward Huang, and Kia Holt, joined our lab for their first rotation

Nancy, Adriana, Diandra, Xiomarie, Andrea, and Sam attended ASM Microbe meeting in Washington DC, with Diandra and Xiomarie presenting posters and Sam giving a talk