Alexander Horswill, PhD
Professor, Immunology and Microbiology


  • Lyon LM, Doran KS, Horswill AR. Staphylococcus aureus Fibronectin-Binding Proteins Contribute to Colonization of the Female Reproductive Tract. Infect Immun. 2022 Dec 13;:e0046022. [Epub ahead of print] PubMed PMID: 36511703
  • Langouët-Astrié C, Oshima K, McMurtry SA, Yang Y, Kwiecinski JM, LaRivière WB, Kavanaugh JS, Zakharevich I, Hansen KC, Shi D, Zhang F, Boguslawski KM, Perelman SS, Su G, Torres VJ, Liu J, Horswill AR, Schmidt EP. The influenza-injured lung microenvironment promotes MRSA virulence, contributing to severe secondary bacterial pneumonia. Cell Rep. 2022 Nov 29;41(9):111721. PubMed PMID: 36450248
  • Keogh RA, Haeberle AL, Langouët-Astrié CJ, Kavanaugh JS, Schmidt EP, Moore GD, Horswill AR, Doran KS. Group B Streptococcus adaptation promotes survival in a hyperinflammatory diabetic wound environment. Sci Adv. 2022 Nov 11;8(45):eadd3221. PubMed PMID: 36367946
  • Mills KB, Roy P, Kwiecinski JM, Fey PD, Horswill AR. Staphylococcal Corneocyte Adhesion: Assay Optimization and Roles of Aap and SasG Adhesins in the Establishment of Healthy Skin Colonization. Microbiol Spectr. 2022 Dec 21;10(6):e0246922. PubMed PMID: 36219106
  • Lee J, Carda-Diéguez M, Ĺ˝iemyte M, Vreugde S, Cooksley C, Crosby HA, Horswill AR, Mira A, Zilm PS, Kidd SP. Functional mgrA Influences Genetic Changes within a Staphylococcus aureus Cell Population over Time. J Bacteriol. 2022 Oct 18;204(10):e0013822. PubMed PMID: 36154359
  • Severn MM, Horswill AR. Staphylococcus epidermidis and its dual lifestyle in skin health and infection. Nat Rev Microbiol. 2022 Aug 30. [Epub ahead of print] PubMed PMID: 36042296
  • Severn MM, Cho YK, Manzer HS, Bunch ZL, Shahbandi A, Todd DA, Cech NB, Horswill AR. The Commensal Staphylococcus warneri Makes Peptide Inhibitors of MRSA Quorum Sensing that Protect Skin from Atopic or Necrotic Damage. J Invest Dermatol. 2022 Dec;142(12):3349-3352.e5. PubMed PMID: 35803321
  • Kwiecinski JM, Jelani DA, Fuentes EJ, Horswill AR. Therapeutic Inhibition of Staphylococcus aureus ArlRS Two-Component Regulatory System Blocks Virulence. Antimicrob Agents Chemother. 2022 Jul 19;66(7):e0018722. PubMed PMID: 35736133
  • Haynes AS, Prinzi A, Silveira LJ, Parker SK, Lampe JN, Kavanaugh JS, Horswill AR, Fish D. Cefadroxil Comparable to Cephalexin: Minimum Inhibitory Concentrations among Methicillin-Susceptible Staphylococcus aureus Isolates from Pediatric Musculoskeletal Infections. Microbiol Spectr. 2022 Aug 31;10(4):e0103922. PubMed PMID: 35730963
  • Costa FG, Horswill AR. Overcoming pH defenses on the skin to establish infections. PLoS Pathog. 2022 May;18(5):e1010512. PubMed PMID: 35617212
  • Severn MM, Williams MR, Shahbandi A, Bunch ZL, Lyon LM, Nguyen A, Zaramela LS, Todd DA, Zengler K, Cech NB, Gallo RL, Horswill AR. The Ubiquitous Human Skin Commensal Staphylococcus hominis Protects against Opportunistic Pathogens. mBio. 2022 Jun 28;13(3):e0093022. PubMed PMID: 35608301
  • de Vor L, van Dijk B, van Kessel K, Kavanaugh JS, de Haas C, Aerts PC, Viveen MC, Boel EC, Fluit AC, Kwiecinski JM, Krijger GC, Ramakers RM, Beekman FJ, Dadachova E, Lam MG, Vogely HC, van der Wal BC, van Strijp JA, Horswill AR, Weinans H, Rooijakkers SH. Human monoclonal antibodies against Staphylococcus aureus surface antigens recognize in vitro and in vivo biofilm. Elife. 2022 Jan 6;11. PubMed PMID: 34989676
  • Staats A, Burback PW, Schwieters A, Li D, Sullivan A, Horswill AR, Stoodley P. Rapid Aggregation of Staphylococcus aureus in Synovial Fluid Is Influenced by Synovial Fluid Concentration, Viscosity, and Fluid Dynamics, with Evidence of Polymer Bridging. mBio. 2022 Apr 26;13(2):e0023622. PubMed PMID: 35254134
  • Mills KB, Jia F, Stein ME, Keim KC, Davidson RM, Horswill AR. Genome Sequences of Two Methicillin-Sensitive Staphylococcus aureus Healthy Skin Isolates. Microbiol Resour Announc. 2022 Jun 16;11(6):e0040222. PubMed PMID: 35575560
  • Leyva-Castillo JM, Das M, Kane J, Strakosha M, Singh S, Wong DSH, Horswill AR, Karasuyama H, Brombacher F, Miller LS, Geha RS. Basophil-derived IL-4 promotes cutaneous Staphylococcus aureus infection. JCI Insight. 2021 Nov 8;6(21). PubMed PMID: 34747366
  • Kwiecinski JM, Kratofil RM, Parlet CP, Surewaard BGJ, Kubes P, Horswill AR. Staphylococcus aureus uses the ArlRS and MgrA cascade to regulate immune evasion during skin infection. Cell Rep. 2021 Jul 27;36(4):109462. PubMed PMID: 34320352
  • Hook JS, Patel PA, O'Malley A, Xie L, Kavanaugh JS, Horswill AR, Moreland JG. Lipoproteins from Staphylococcus aureus Drive Neutrophil Extracellular Trap Formation in a TLR2/1- and PAD-Dependent Manner. J Immunol. 2021 Aug 1;207(3):966-973. PubMed PMID: 34290104
  • Crosby HA, Kwiecinski JM, Horswill AR. In Vitro Assay for Quantifying Clumping of Staphylococcus aureus. Methods Mol Biol. 2021;2341:31-36. PubMed PMID: 34264458
  • Salam AM, Porras G, Cho YK, Brown MM, Risener CJ, Marquez L, Lyles JT, Bacsa J, Horswill AR, Quave CL. Castaneroxy A From the Leaves of Castanea sativa Inhibits Virulence in Staphylococcus aureus . Front Pharmacol. 2021;12:640179. PubMed PMID: 34262448
  • Roy P, Horswill AR, Fey PD. Glycan-Dependent Corneocyte Adherence of Staphylococcus epidermidis Mediated by the Lectin Subdomain of Aap. mBio. 2021 Aug 31;12(4):e0290820. PubMed PMID: 34253065
  • West KHJ, Shen W, Eisenbraun EL, Yang T, Vasquez JK, Horswill AR, Blackwell HE. Non-Native Peptides Capable of Pan-Activating the agr Quorum Sensing System across Multiple Specificity Groups of Staphylococcus epidermidis . ACS Chem Biol. 2021 Jun 18;16(6):1070-1078. PubMed PMID: 33988969
  • Nakamura K, Williams MR, Kwiecinski JM, Horswill AR, Gallo RL. Staphylococcus aureus Enters Hair Follicles Using Triacylglycerol Lipases Preserved through the Genus Staphylococcus. J Invest Dermatol. 2021 Aug;141(8):2094-2097. PubMed PMID: 33705795
  • Amjadi MF, Avner BS, Greenlee-Wacker MC, Horswill AR, Nauseef WM. Neutrophil-derived extracellular vesicles modulate the phenotype of naïve human neutrophils. J Leukoc Biol. 2021 Nov;110(5):917-925. PubMed PMID: 33682200
  • Nakamura K, O'Neill AM, Williams MR, Cau L, Nakatsuji T, Horswill AR, Gallo RL. Short chain fatty acids produced by Cutibacterium acnes inhibit biofilm formation by Staphylococcus epidermidis. Sci Rep. 2020 Dec 4;10(1):21237. PubMed PMID: 33277548
  • Brown MM, Horswill AR. Staphylococcus epidermidis-Skin friend or foe?. PLoS Pathog. 2020 Nov;16(11):e1009026. PubMed PMID: 33180890
  • Bispo M, Anaya-Sanchez A, Suhani S, Raineri EJM, López-Álvarez M, Heuker M, Szymanski W, Romero Pastrana F, Buist G, Horswill AR, Francis KP, van Dam GM, van Oosten M, van Dijl JM. Fighting Staphylococcus aureus infections with light and photoimmunoconjugates. JCI Insight. 2020 Nov 19;5(22). PubMed PMID: 33048846
  • Kavanaugh JS, Leidal KG, Nauseef WM, Horswill AR. Cathepsin G degrades Staphylococcus aureus biofilms. J Infect Dis. 2020 Sep 30. [Epub ahead of print] PubMed PMID: 32995850
  • Schilcher K, Horswill AR. Staphylococcal Biofilm Development: Structure, Regulation, and Treatment Strategies. Microbiol Mol Biol Rev. 2020 Aug 19;84(3). PubMed PMID: 32792334
  • Gupta TT, Gupta NK, Pestrak MJ, Dusane DH, Harro JM, Horswill AR, Stoodley P. Staphylococcus aureus Aggregates on Orthopedic Materials under Varying Levels of Shear Stress. Appl Environ Microbiol. 2020 Sep 17;86(19). PubMed PMID: 32709721
  • Häffner N, Bär J, Dengler Haunreiter V, Mairpady Shambat S, Seidl K, Crosby HA, Horswill AR, Zinkernagel AS. Intracellular Environment and agr System Affect Colony Size Heterogeneity of Staphylococcus aureus . Front Microbiol. 2020;11:1415. PubMed PMID: 32695082
  • Jones DD Jr, Caesar LK, Pelzer CV, Crandall WJ, Jenul C, Todd DA, Horswill AR, Cech NB. Targeted and untargeted analysis of secondary metabolites to monitor growth and quorum sensing inhibition for methicillin-resistant Staphylococcus aureus (MRSA). J Microbiol Methods. 2020 Sep;176:106000. PubMed PMID: 32649968
  • Cau L, Williams MR, Butcher AM, Nakatsuji T, Kavanaugh JS, Cheng JY, Shafiq F, Higbee K, Hata TR, Horswill AR, Gallo RL. Staphylococcus epidermidis protease EcpA can be a deleterious component of the skin microbiome in atopic dermatitis. J Allergy Clin Immunol. 2020 Jul 4. [Epub ahead of print] PubMed PMID: 32634452
  • Tang H, Porras G, Brown MM, Chassagne F, Lyles JT, Bacsa J, Horswill AR, Quave CL. Triterpenoid acids isolated from Schinus terebinthifolia fruits reduce Staphylococcus aureus virulence and abate dermonecrosis. Sci Rep. 2020 May 15;10(1):8046. PubMed PMID: 32415287
  • Pestrak MJ, Gupta TT, Dusane DH, Guzior DV, Staats A, Harro J, Horswill AR, Stoodley P. Investigation of synovial fluid induced Staphylococcus aureus aggregate development and its impact on surface attachment and biofilm formation. PLoS One. 2020;15(4):e0231791. PubMed PMID: 32302361
  • Schilcher K, Caesar LK, Cech NB, Horswill AR. Processing, Export, and Identification of Novel Linear Peptides from Staphylococcus aureus. mBio. 2020 Apr 14;11(2). PubMed PMID: 32291297
  • Brown MM, Kwiecinski JM, Cruz LM, Shahbandi A, Todd DA, Cech NB, Horswill AR. Novel Peptide from Commensal Staphylococcus simulans Blocks Methicillin-Resistant Staphylococcus aureus Quorum Sensing and Protects Host Skin from Damage. Antimicrob Agents Chemother. 2020 May 21;64(6). PubMed PMID: 32253213
  • Kwiecinski JM, Horswill AR. Staphylococcus aureus bloodstream infections: pathogenesis and regulatory mechanisms. Curr Opin Microbiol. 2020 Feb;53:51-60. PubMed PMID: 32172183
  • Williams MR, Cau L, Wang Y, Kaul D, Sanford JA, Zaramela LS, Khalil S, Butcher AM, Zengler K, Horswill AR, Dupont CL, Hovnanian A, Gallo RL. Interplay of Staphylococcal and Host Proteases Promotes Skin Barrier Disruption in Netherton Syndrome. Cell Rep. 2020 Mar 3;30(9):2923-2933.e7. PubMed PMID: 32130897
  • DelMain EA, Moormeier DE, Endres JL, Hodges RE, Sadykov MR, Horswill AR, Bayles KW. Stochastic Expression of Sae-Dependent Virulence Genes during Staphylococcus aureus Biofilm Development Is Dependent on SaeS. mBio. 2020 Jan 14;11(1). PubMed PMID: 31937649
  • Sirobhushanam S, Parsa N, Reed TJ, Berthier CC, Sarkar MK, Hile GA, Tsoi LC, Banfield J, Dobry C, Horswill AR, Gudjonsson JE, Kahlenberg JM. Staphylococcus aureus Colonization Is Increased on Lupus Skin Lesions and Is Promoted by IFN-Mediated Barrier Disruption. J Invest Dermatol. 2020 May;140(5):1066-1074.e4. PubMed PMID: 31877319
  • Sirobhushanam S, Parsa N, Reed TJ, Berthier CC, Sarkar MK, Hile GA, Tsoi LC, Banfield J, Dobry C, Horswill AR, Gudjonsson JE, Kahlenberg JM. Staphylococcus aureus colonization is increased on lupus skin lesions and is promoted by interferon-mediated barrier disruption. J Invest Dermatol. 2019 Dec 23. [Epub ahead of print] PubMed PMID: 31877319
  • Kwiecinski JM, Crosby HA, Valotteau C, Hippensteel JA, Nayak MK, Chauhan AK, Schmidt EP, Dufrêne YF, Horswill AR. Staphylococcus aureus adhesion in endovascular infections is controlled by the ArlRS-MgrA signaling cascade. PLoS Pathog. 2019 May;15(5):e1007800. PubMed PMID: 31116795
  • Borbón TY, Scorza BM, Clay GM, Lima Nobre de Queiroz F, Sariol AJ, Bowen JL, Chen Y, Zhanbolat B, Parlet CP, Valadares DG, Cassel SL, Nauseef WM, Horswill AR, Sutterwala FS, Wilson ME. Coinfection with Leishmania major and Staphylococcus aureus enhances the pathologic responses to both microbes through a pathway involving IL-17A. PLoS Negl Trop Dis. 2019 May;13(5):e0007247. PubMed PMID: 31107882
  • Williams MR, Costa SK, Zaramela LS, Khalil S, Todd DA, Winter HL, Sanford JA, O'Neill AM, Liggins MC, Nakatsuji T, Cech NB, Cheung AL, Zengler K, Horswill AR, Gallo RL. Quorum sensing between bacterial species on the skin protects against epidermal injury in atopic dermatitis. Sci Transl Med. 2019 May 1;11(490). PubMed PMID: 31043573
  • Kwiecinski JM, Jacobsson G, Horswill AR, Josefsson E, Jin T. Biofilm formation by Staphylococcus aureus clinical isolates correlates with the infection type. Infect Dis (Lond). 2019 Jun;51(6):446-451. PubMed PMID: 30985241
  • Tian X, Hellman J, Horswill AR, Crosby HA, Francis KP, Prakash A. Elevated Gut Microbiome-Derived Propionate Levels Are Associated With Reduced Sterile Lung Inflammation and Bacterial Immunity in Mice. Front Microbiol. 2019;10:159. PubMed PMID: 30891007
  • Trivedi U, Madsen JS, Everett J, Fell C, Russel J, Haaber J, Crosby HA, Horswill AR, Burmølle M, Rumbaugh KP, Sørensen SJ. Staphylococcus aureus coagulases are exploitable yet stable public goods in clinically relevant conditions. Proc Natl Acad Sci U S A. 2018 Dec 11;115(50):E11771-E11779. PubMed PMID: 30463950
  • Loftus RW, Dexter F, Robinson ADM, Horswill AR. Desiccation tolerance is associated with Staphylococcus aureus hypertransmissibility, resistance and infection development in the operating room. J Hosp Infect. 2018 Nov;100(3):299-308. PubMed PMID: 29966756
  • Urbano R, Karlinsey JE, Libby SJ, Doulias PT, Ischiropoulos H, Warheit-Niemi HI, Liggitt DH, Horswill AR, Fang FC. Host Nitric Oxide Disrupts Microbial Cell-to-Cell Communication to Inhibit Staphylococcal Virulence. Cell Host Microbe. 2018 May 9;23(5):594-606.e7. PubMed PMID: 29706505
  • Chen Y, Crosby HA, Oosthuysen WF 2nd, Diekema DJ, Kelley ST, Horswill AR. Draft Genome Sequence of USA100 Methicillin-Resistant Staphylococcus aureus Strain 209. Genome Announc. 2018 Jan 4;6(1). PubMed PMID: 29301880
  • Quave CL, Horswill AR. Identification of Staphylococcal Quorum Sensing Inhibitors by Quantification of õ-Hemolysin with High Performance Liquid Chromatography. Methods Mol Biol. 2018;1673:363-370. PubMed PMID: 29130186
  • Muhs A, Lyles JT, Parlet CP, Nelson K, Kavanaugh JS, Horswill AR, Quave CL. Virulence Inhibitors from Brazilian Peppertree Block Quorum Sensing and Abate Dermonecrosis in Skin Infection Models. Sci Rep. 2017 Feb 10;7:42275. PubMed PMID: 28186134
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General Information

Department: Immunology and Microbiology
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