Research

Current Research

This diverse research portfolio and study pipeline, yields immediate or near-immediate impacts on patient care, provides access to required samples for future research, and establishes an infrastructure to translate findings from the bench to the bedside. Examples include: NIH R34 Phase II antifungal candidemia trials, Gates Foundation-funded trials seeking to decrease maternal and neonatal mortality, CDC-funded research to determine the true parasite burden in rural AL (reportedly the highest in the nation), and inclusion as a core lab in multiple NIH U54 and PPG grant submissions.

Examples of the Leal lab’s translational diagnostic research include the evaluation of commercial diagnostic platforms seeking US FDA approval for rapid detection of pathogens and antimicrobial resistance genes in blood and respiratory samples, viral vs non-viral meningitis, detection of macrolide-resistant mollicutes, candidemia, invasive mold infections, and Clostridiodes difficile. Dr. Leal’s lab was also the 1^st in the State of AL to develop and offer PCR tests for SARS-CoV-2 (SARS-2) and Monkeypox. As the Director of UAB’s BSL-3 research facility (SEBLAB), UAB Hospitals clinical microbiology lab, and the UAB Fungal Reference Lab (FRL), the Leal lab continues to be very well positioned at the frontline diagnostic response to emerging microbial threats. Receipt of the 2020 UAB Faculty Innovator of the Year Award exemplifies the high level of innovation in the Leal lab translational research program. Additional highlights include: Most sensitive diagnostic test for SARS-2 in the US (based on comparative FDA data), innovative pooled testing strategy to enable a safe return to AL college campuses, establishment of wastewater COVID surveillance, and 1st detection of all major SARS-CoV-2 variants in AL.

Representative Citations:

1. Johnson MG, Leal Jr. SM, Plongla R, Leone PA, Gilligan PH. The Brief Case: Recurrent Granulomatous Mastitis Due to Corynebacterium kroppenstedtii. J Clin Microbiology. 2016. 1;54(8):1938-41. PMID: 27458268
2. Leal Jr. SM, Jones M, and Gilligan PH. The clinical significance of commensal gram- positive rods routinely isolated from clinical samples. J Clin Microbiology. 2016.54.12: 2928-2936. PMID:27629905
3. Leal Jr. SM., and Margaret L. Gulley. Current and Emerging Molecular Tests for Human Papillomavirus–Related Neoplasia in the Genomic Era. J Molecular Diagnostics. 2017. Volume 19, Issue 3, 366-377, PMID: 28325688
4. Leal Jr. SM, Popowitch EB, Levinson KJ, John TM, Lehman B, Rios MB, and Miller MB. Quantitative thresholds enable accurate identification of Clostridium difficile infection by the Luminex xTAG GI pathogen panel. J Clin Microbiology. 2018. JCM-01885. PMID: 29643194
5. Totten AH, Leal Jr. SM, Ratliff AE, Li Xiao, Crabb DM, and Waites KB. Evaluation of the ELITe InGenius^® PCR for Detection of Mycoplasma pneumoniae. J Clin Microbiology. 2019.  doi:10.1128/JCM.00287-19. PMID: 30971463
6. Lehman, B., Leal Jr. SM., Procop, G.W., O’Connell, E., Shaik, J., Nash, T.E., Nutman, T.B., Jones, S., Braunthal, S., Shah, S.N. and Cruise, M.W. Disseminated Metacestode Versteria Species Infection in Woman, Pennsylvania, USA. Emerging Infectious Diseases.2019. 25(7), p.1429. PMID: 31211937
7. Richter, S.S., Otiso, J., Goje, O.J., Vogel, S., Aebly, J., Keller, G., Van Heule, H., Wehn, D., Stephens, A.L., Zanotti, S., Johnson, T., Leal Jr. S.M., Procop G.W., 2019. Prospective Evaluation of Molecular Assays for Diagnosis of Vaginitis. J Clin Microbiology.2019.58(1). PMID: 31694966
8. Alishlash, A.S., Atkinson, T.P., Schlappi, C., Leal Jr. S.M., Waites, K.B. and Xiao, L. Mycoplasma pneumoniae carriage with de novo macrolide-resistance and breakthrough pneumonia. Pediatrics. 2019. 144(4), p.e20191642. PMID: 32817226
9. Higgins, A.B., Farmakiotis, D., Rogers, R., Osband, A.J., Seo, A., Chen, B., Birkenbach, M.P., Crabb, D., Xiao, L., Leal Jr. S.M. and Waites, K. Hyperammonemia syndrome due to Ureaplasma urealyticum in a kidney transplant recipient: a case of disseminated disease from a fluoroquinolone‐resistant isolate. Transplant Infectious Disease. 2020. p.e13328. PMID: 32416005
10. Wei, Q., Leal Jr. S.M., Qarmali, M., Wilcox, C.M., Patel, C.R. and Al Diffalha, S., Sarcina ventriculi: A Rare Case of Life-Threatening Perforated Gastric Ulcer and Review of Literature. J Gastric Surgery. 2020. 2(2), pp.53-56.
11. Walker, J., Fleece, M.E., Griffin, R.L., Leal Jr. S.M., Alsip, J.A., Stigler, W.S., Nafziger, S.D., Marrazzo, J.M. and Lee, R.A. Decreasing High Risk Exposures for Healthcare-workers through Universal Masking and Universal SARS-CoV-2 Testing upon entry to a Tertiary Care Facility. Clinical Infectious Diseases. 2020. PMID: 32901247
12. Leal Jr. S.M., Totten, A.H., Xiao, L., Crabb, D.M., Ratliff, A., Duffy, L.B., Fowler, K.B., Mixon, E., Winchell, J.M., Diaz, M.H. and Benitez, A.J. Evaluation of Commercial Molecular Diagnostic Methods for Detection and Determination of Macrolide Resistance in Mycoplasma pneumoniae. J Clin Microbiology. 2020. 58(6). PMID: 32269102
13. Waites, K.B., Crabb, D.M., Xiao, L., Duffy, L.B. and Leal Jr. S.M*. In Vitro Activities of Eravacycline and Other Antimicrobial Agents Against Human Mycoplasmas and Ureaplasmas. Antimicrobial Agents and Chemotherapy. 2020. PMID: 32513794
14. Zhang, S.,  Babady E., Hanson, KE,  Harrington, AT,  Larkin, P,  Leal Jr. S.M.,  Luethy, PM,  Martin IW, Pancholi  P, Procop GW, Riedel S, Seyedmousavi S,  Sullivan, KV , Walsh, TJ,  Lockhart, SR. Recognition of Diagnostic Gaps for Laboratory Diagnosis of Fungal Infections: Expert Opinion from the Fungal Diagnostics Laboratories Consortium (FDLC). J Clin Microbiology. 2021. PMID: 33504591
15. John, T.M., Shrestha, N.K., Procop, G.W., Grove, D., Leal Jr, S.M., Jacob, C.N., Butler, R. and Dweik, R., 2021. Diagnosis of Clostridioides difficile infection by analysis of volatile organic compounds in breath, plasma, and stool: A cross-sectional proof-of-concept study. PloS one, 16(8), p.e0256259. PMID: 34407120
16. Leal Jr, S.M.*, Rodino, K.G., Fowler, W.C. and Gilligan, P.H., 2021. Practical Guidance for Clinical Microbiology Laboratories: Diagnosis of Ocular Infections. Clinical Microbiology Reviews, 34(3), pp.e00070-19.PMID: 34076493
17. Shanmugam, C., Behring, M., Luthra, V., Leal Jr., S.M., Varambally, S., Netto, G.J. and Manne, U., 2022. Meta-analysis of the robustness of COVID-19 diagnostic kit performance during the early pandemic. BMJ open, 12(4), p.e053912. PMID: 35450897
18. McCarty, T.P., White C.M., Meeder J., Moates, D., Pierce, H.M., Edwards S.W., Hutchinson, J., Lee, R.A., Leal Jr, S.M*. Analytical performance and potential clinical utility of the GenMark Dx ePlex® blood culture identification gram-positive panel. Diagnostic Microbiology and Infectious Diseases. 2022 Jul 11;104(3):115762. PMID: 35988351
19. Guillamet, L. J. V., Marx, G. E., Benjamin, W., Pappas, P., Lieberman, N. A., Bachiashvili, K., Leal Jr, S.M., & Lieberman, J. A. (2023). Relapsing Fever Caused by Borrelia lonestari after Tick Bite in Alabama, USA. Emerging Infectious Diseases, 29(2). PMID: 36692856
20. McCarty, T.P., Cumagun, P., Meeder, J., Moates, D., Edwards, W.S., Hutchinson, J., Lee, R.A. and Leal Jr, S.M.* , 2023. Test Performance and Potential Clinical Utility of the GenMark Dx ePlex Blood Culture Identification Gram-Negative Panel. Microbiology Spectrum, 11(1), pp.e04092-22. PMID: 36688641
21. Herrera, L.N., Khodadadi, R., Leal Jr, S.M., Kulkarni, P., Pappas, P. and McCarty, T., 2023. Clinical Utility of Routine Use of Fungal Blood Cultures. The American Journal of Medicine. PMID: 36849070
22. de Hoog, S., Walsh, T. J., Ahmed, S. A., Alastruey-Izquierdo, A., Alexander, B. D., Arendrup, M. C., Leal Jr., SM … & Zhang, S. X. (2023). A conceptual framework for nomenclatural stability and validity of medically important fungi: a proposed global consensus guideline for fungal name changes supported by ABP, ASM, CLSI, ECMM, ESCMID-EFISG, EUCAST-AFST, FDLC, IDSA, ISHAM, MMSA, and MSGERC. Journal of Clinical Microbiology, e00873-23. PMID: 37882528
23. Doernberg, S. B., Arias, C. A., Altman, D. R., Babiker, A., Boucher, H. W., Creech, C. B., Leal Jr., SM …… & Holland, T. L. (2023). Priorities and Progress in Gram-positive Bacterial Infection Research by the Antibacterial Resistance Leadership Group: A Narrative Review. Clinical Infectious Diseases, 77(Supplement_4), S295-S304. PMID: 37843115
24. de Hoog, S., Walsh, T.J., Ahmed, S.A., Alastruey-Izquierdo, A., Alexander, B.D., Arendrup, M.C., Babady, E., Bai, F.Y., Balada-Llasat, J.M., Borman, A. Leal Jr., S.M., … and Chowdhary, A., 2024. Reply to Kidd et al.,“Inconsistencies within the proposed framework for stabilizing fungal nomenclature risk further confusion”. Journal of Clinical Microbiology, pp.e01625-23. PMID: 38441056
25. Graffice, E., Moates, D., Leal Jr, S.M., Amerson-Brown, M. and Calix, J.J., 2024. Epidemiological, phylogenetic, and resistance heterogeneity among Acinetobacter baumannii in a major US Deep South healthcare center. medRxiv, pp.2024-03.
26. Miller JM, Binnicker MJ, Campbell S, Carroll KC, Chapin KC, Gonzalez MD, Harrington A, Jerris RC, Kehl SC, Leal Jr., SM, Patel R, Pritt BS, Richter SS, Robinson-Dunn B, Snyder JW, Telford S 3rd, Theel ES, Thomson RB Jr, Weinstein MP, Yao JD. Guide to Utilization of the Microbiology Laboratory for Diagnosis of Infectious Diseases: 2024 Update by the Infectious Diseases Society of America (IDSA) and the American Society for Microbiology (ASM). Clin Infect Dis. 2024 Mar 5:ciae104. doi: 10.1093/cid/ciae104. PMID: 38442248.

As mycologists uniquely immersed in SARS-2, the Leal lab became highly interested in reports of up to 35% of patients intubated with severe COVID developing 2° mold infection with high mortality (40-60%). Our team led the laboratory component of a 7-center US clinical trial identifying a 5-10% overall incidence of COVID-associated Aspergillosis (CAPA) in patients intubated with severe SARS-CoV-2 infection. Given our lab’s unique combination of expertise in fungal pathogenesis, immunology, and SARS-2 biology, access to archived BAL and FFPE samples, lab personnel with > 20 years of BSL-3/ABSL-3 experience, access to isogenic mutant fungal strains, and well established key collaborations,  we set out to evaluate the following hypothesis: Immune responses targeting intracellular viral pathogens, like SARS-2, promote 2° mold infection via lytic programmed cell death (PCD) in pulmonary epithelial cells (PEC) and red blood cell hemolysis, which increases the availability of nutrients including iron/heme available to drive siderophore-dependent mold growth. Concurrently, SARS-2 and the antiviral cytokine milieu mitigate PMN recruitment and activation resulting in spore germination into large invasive hyphae that overwhelm antifungal effector mechanisms enabling 2° mold infection in an otherwise immunocompetent host. This work is ongoing and funded by the American Lung Association (ALA) as well as NIAID R01 AI 170719-01 “The Impact of SARS-CoV-2 Immune Dysregulation on Antifungal Immunity.” Innovations include: 1) Novel evaluation of bioavailable metals, in situ gene expression, in situ metallomics, host lytic programmed cell death, and critical host and microbial factors mediating fungal growth in the lower airways of patients with severe SARS-2 infection. 2) Novel use of spatial transcriptomics, spatial metallomics, CRISPR-CAS-edited Calu-3 cells, 1° NHBE ALI cultures, PMN airway transmigration models, and isogenic mutant fungi to evaluate host:viral:fungal interactions. 3) Novel development and utilization of an experimental murine CAPA model, fluorescent microbes, and single cell sequencing to dissect the pathophysiology of 2° mold infection and evaluate the pre-clinical utility of small molecule inhibitors to prevent and treat this devastating infection in otherwise immunocompetent hosts. 

Representative Citations:

1. Liu, W., Russell, R.M., Bibollet-Ruche, F., Skelly, A.N., Sherrill-Mix, S., Freeman, D.A., Stoltz, R., Lindemuth, E., Lee, F.H., Sterrett, S., Leal Jr, S.M., Goepfert, P., Hahn, BH 2021. Predictors of Nonseroconversion after SARS-CoV-2 Infection. Emerging Infectious Diseases, 27(9), p.2454. PMID: 34193339
2. Seasely, A.R., Blanchard, C.T., Arora, N., Battarbee, A.N., Leal Jr, S.M, Casey, B.M., Dionne-Odom, J., Sinkey, R.G., Szychowski, J.M., Tita, A.T., Subramaniam, A. and CWRH COVID-19 Working Group, 2021. Maternal and Perinatal Outcomes Associated With the Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) Delta (B. 1.617. 2) Variant. Obstetrics & Gynecology, pp.10-1097. PMID: 34592747
3. Li, Q., Vijaykumar, K., Phillips, S., Hussain, S.S., Huynh, V.N., Fernandez-Petty, C.M., Lever, J.E.P., Foote, J.B., Ren, J., Campos-Gomez, J., Abou Daya, Leal Jr, S.M. … & Rowe, S.M.., 2022. Mucociliary Transport Deficiency and Disease Progression in Syrian Hamsters with SARS-CoV-2 Infection. JCI Insight 2023 Jan 10; 8(1): e163962. PMID: 36625345
4. Seasely, A.R., Blanchard, C.T., Arora, N., Battarbee, A.N., Casey, B.M., Dionne-Odom, J., Leal Jr, S.M., Moates, D.B., Sinkey, R.G., Szychowski, J.M. and Tita, A.T., 2022. Maternal and Perinatal Outcomes Associated With the Omicron Variant of Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) Infection. Obstetrics & Gynecology, pp.10-1097. PMID: 35852277
5. Vijaykumar, K., Leung, H.M., Barrios, A., Fernandez-Petty, C.M., Solomon, G.M., Hathorne, H.Y., Wade, J.D., Monroe, K., Slaten, K.B., Li, Q. Leal Jr., S.M., Moates, D., Pierce, H.M., Olson K.R., Currier P., Foster S., Marsden D., Tearney G.J., and Rowe, S.M., 2022. COVID-19 Causes Ciliary Dysfunction as Demonstrated by Human Intranasal Micro-Optical Coherence Tomography Imaging. bioRxiv. PMID: 35860227
6. Killian Jr, J.T., Houp, J.A., Burkholder, G.A., Roman Soto, S.A., Killian, A.C., Ong, S.C., Erdmann, N.B., Goepfert, P.A., Hauptfeld-Dolejsek, V., Leal Jr, S.M. and Zumaquero, E., 2022. COVID-19 Vaccination and Remdesivir are Associated With Protection From New or Increased Levels of Donor-Specific Antibodies Among Kidney Transplant Recipients Hospitalized With COVID-19. Transplant International, p.149. PMID: 35928347
7. Margaroli C, Fram TR, Sharma NS, Patel SB, Tipper J, Robison SW, Russell DW, Fortmann SD, Banday MM, Soto-Vazquez YM, Abdalla T. Leal Jr, S.M., …Gaggar A., Interferon-dependent signaling is critical for viral clearance in airway neutrophils. JCI insight. 2023 Apr 18. PMID: 37071484
8. Riegler AN, Benson P, Long K, Leal Jr., SM. Differential activation of programmed cell death in patients with severe SARS-CoV-2 infection. Cell Death Discovery. 2023 Nov 20;9(1):420. PMID: 37985756

 

The Leal lab utilizes in vivo murine models of dimorphic fungal infections, including Histoplasma and Coccidiodes species to study the efficacy of novel therapeutics against these difficult-to-treat TB-like infections. These pre-clinical models are also being used to develop and evaluate the utility of novel non-invasive diagnostic imaging tests for difficult-to-diagnose and treat RGIII pathogens. Given close collaboration with the Mycoses Study Group (MSG) and a very active radiology clinical trials group, the Leal lab is well positioned to move promising pre-clinical candidates to clinical trials.  

The Leal lab also addresses a perplexing fundamental question in medical mycology: Why certain RGIII dematiaceous (pigmented) molds can cause isolated and debilitating brain infections in otherwise healthy hosts? Based on the high expression of fungal melanin on the cell wall of neurotropic molds (Rhinocladiella mackenzeii, Cladophialophora bantiana, Verruconis gallopava, Exophiala dermatitidis) and the neurotropic yeast Cryptococcus, we are pursuing several hypotheses to understand the mechanism mediating fungal neurotropism. Pathogenic dematiaceous molds are notoriously understudied, and this work has significant implications for millions of otherwise healthy individuals in predominantly marginalized equatorial minority populations afflicted with tumor-like fungus balls (mycetomas), cornea infections (keratitis), chronic pyogranulomatous skin lesions (chromoblastomycosis), and invasive mold infection (phaeohyphomycosis).

The Leal lab utilizes novel mouse model systems as well as in vitro, and ex vivo models to study host and microbial factors as well as therapeutic interventions mediating infection outcome. The lab also engages in critical international collaborations with colleagues in South India to characterize and study fungal keratitis in high-incidence communities to mitigate the global impact of this devastating infection. Research highlights include: Innovative development of the first RFP-expressing A. fumigatus (Af) strain, Af fungal keratitis murine model, and PMN adoptive transfer model. These systems were then used to identify critical innate immune defense mechanisms and fungal factors (antioxidant defense; iron acquisition) mediating infection outcome. Several small molecules targeting fungal survival were identified and patented. Several mechanistic hypotheses and novel therapeutics are actively being evaluated in the lab.

Representative Citations:

1. Leal Jr. SM,  Hastings S, Hsia YC,  Ghannoum M, Momany M, and Pearlman E. Distinct roles for Dectin- 1 and TLR4 in the pathogenesis of Aspergillus fumigatus keratitis. PLoS Pathogens. 07/2010; 6(7): e1000976. doi:10.1371/journal.ppat.1000976. PMID: 20617171.
2. Carrion SDJ, Leal Jr. SM, Amanianda V, Latge JP, Ghannoum M, and Pearlman E.. RodA hydrophobin on Aspergillus and Fusarium conidia masks Dectin-1 and Dectin-2 responses and enhances fungal survival. J Immunology. 2013. 191(5), pp.2581-2588. PMID:23926321
3. Karthikeyan RS, Leal Jr. SM, Prajna V,  Dharmalingam K, Geiser DM, Pearlman E, and  Prajna L.  Expression of innate and adaptive immune mediators in human corneal tissue infected with Aspergillus or Fusarium. Journal of Infectious Disease. 08/2011; 204(6): 942-950. PMID: 21828275
4. Leal Jr. SM, Vareechon C, Cowden S, Cobb BA, Latge JP, Momany M, Pearlman E. Fungal antioxidant pathways promote survival against neutrophils during infection. Journal of ClinicalInvestigation. 07/2012. 122(7):2482–2498, PMID: 22706306. 
5. Taylor PR, Leal Jr. SM, Sun Y, and Pearlman E. Aspergillus and Fusarium corneal infections are regulated by Th17 cells and IL-17 producing neutrophils. Journal of Immunology. 04/2014. 192(7):3319-27. PMID:24591369
6. Taylor PR, Roy S, Leal Jr. SM, Sun Y, Howell SJ, Cobb BA, Li X, and Pearlman E. Activation of neutrophils by autocrine IL-17A-IL-17RC interactions during fungal infection is regulated by IL-6, IL-23, RORγT, and Dectin-2. Nature Immunology. 02/2014. 15(2):143-51. PMID: 24362892
7. Carrion, S.D.J., Abbondante, S., Clark, H.L., Marshall, M.E., Mouyna, I., Beauvais, A., Sun, Y., Taylor, P.R., Leal Jr. S.M., Armstrong, B., William Carrera, Jean‐Paul Latge, Pearlman E. Aspergillus fumigatus corneal infection is regulated by chitin synthases and by neutrophil–derived acidic mammalian chitinase. European J Immunology. 2019. PMID: 30903663
8. Leal Jr. SM, Roy S, Vareechon C,  Carrion SDJ, Clark H, Lopez-Berges MS, Pietro A, Schrettl M,  Beckmann N, Redl B, Haas H, and Pearlman E. Targeting iron sequestration blocks infection with the fungal pathogens Aspergillus fumigatus and Fusarium oxysporum. PLoS Pathogens. 07/2013. 9(7): e1003436. doi:10.1371/journal.ppat.1003436, PMID:23853581
9. Dietl AM, Amich J, Leal Jr. SM, Beckmann N, Binder U, Beilhack A, Pearlman E, Haas H. Histidine biosynthesis plays a crucial role in metal homeostasis and virulence of Aspergillus fumigatus.Virulence. 2016. 7.4: 465-476. PMID: 26854126
10. Leal Jr, S.M.*, Rodino, K.G., Fowler, W.C. and Gilligan, P.H., 2021. Practical Guidance for Clinical Microbiology Laboratories: Diagnosis of Ocular Infections. Clinical Microbiology Reviews, 34(3), pp.e00070-19.PMID: 34076493
11. Abbondante S, Leal Jr., SM, Clark HL, Ratitong B, Sun Y, Ma LJ, Pearlman E. Immunity to pathogenic fungi in the eye. In Seminars in Immunology 2023 May 1 (Vol. 67, p. 101753). Academic Press. PMID: 37060806
12. Miller JM, Binnicker MJ, Campbell S, Carroll KC, Chapin KC, Gonzalez MD, Harrington A, Jerris RC, Kehl SC, Leal Jr., SM, Patel R, Pritt BS, Richter SS, Robinson-Dunn B, Snyder JW, Telford S 3rd, Theel ES, Thomson RB Jr, Weinstein MP, Yao JD. Guide to Utilization of the Microbiology Laboratory for Diagnosis of Infectious Diseases: 2024 Update by the Infectious Diseases Society of America (IDSA) and the American Society for Microbiology (ASM). Clin Infect Dis. 2024 Mar 5:ciae104. doi: 10.1093/cid/ciae104. PMID: 38442248.