1
|
Zhu Z, Hu Z, Li S, Fang R, Ono HK, Hu DL. Molecular Characteristics and Pathogenicity of Staphylococcus aureus Exotoxins. Int J Mol Sci 2023; 25:395. [PMID: 38203566 PMCID: PMC10778951 DOI: 10.3390/ijms25010395] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2023] [Revised: 12/24/2023] [Accepted: 12/26/2023] [Indexed: 01/12/2024] Open
Abstract
Staphylococcus aureus stands as one of the most pervasive pathogens given its morbidity and mortality worldwide due to its roles as an infectious agent that causes a wide variety of diseases ranging from moderately severe skin infections to fatal pneumonia and sepsis. S. aureus produces a variety of exotoxins that serve as important virulence factors in S. aureus-related infectious diseases and food poisoning in both humans and animals. For example, staphylococcal enterotoxins (SEs) produced by S. aureus induce staphylococcal foodborne poisoning; toxic shock syndrome toxin-1 (TSST-1), as a typical superantigen, induces toxic shock syndrome; hemolysins induce cell damage in erythrocytes and leukocytes; and exfoliative toxin induces staphylococcal skin scalded syndrome. Recently, Panton-Valentine leucocidin, a cytotoxin produced by community-associated methicillin-resistant S. aureus (CA-MRSA), has been reported, and new types of SEs and staphylococcal enterotoxin-like toxins (SEls) were discovered and reported successively. This review addresses the progress of and novel insights into the molecular structure, biological activities, and pathogenicity of both the classic and the newly identified exotoxins produced by S. aureus.
Collapse
Affiliation(s)
- Zhihao Zhu
- Department of Zoonoses, Kitasato University School of Veterinary Medicine, Towada 034-8628, Japan; (Z.Z.); (Z.H.); (H.K.O.)
- College of Veterinary Medicine, Huazhong Agricultural University, Wuhan 430070, China;
| | - Zuo Hu
- Department of Zoonoses, Kitasato University School of Veterinary Medicine, Towada 034-8628, Japan; (Z.Z.); (Z.H.); (H.K.O.)
| | - Shaowen Li
- College of Veterinary Medicine, Huazhong Agricultural University, Wuhan 430070, China;
| | - Rendong Fang
- Joint International Research Laboratory of Animal Health and Animal Food Safety, College of Veterinary Medicine, Southwest University, Chongqing 400715, China;
| | - Hisaya K. Ono
- Department of Zoonoses, Kitasato University School of Veterinary Medicine, Towada 034-8628, Japan; (Z.Z.); (Z.H.); (H.K.O.)
| | - Dong-Liang Hu
- Department of Zoonoses, Kitasato University School of Veterinary Medicine, Towada 034-8628, Japan; (Z.Z.); (Z.H.); (H.K.O.)
| |
Collapse
|
2
|
Tsai CM, Soper N, Bennett M, Fallon JK, Michell AR, Alter G, Liu GY, Thomsen I. Adoptive Transfer of Serum Samples From Children With Invasive Staphylococcal Infection and Protection Against Staphylococcus aureus Sepsis. J Infect Dis 2021; 223:1222-1231. [PMID: 32990305 PMCID: PMC8030728 DOI: 10.1093/infdis/jiaa482] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2020] [Accepted: 07/31/2020] [Indexed: 11/14/2022] Open
Abstract
A successful Staphylococcus aureus vaccine remains elusive, and one controversy in the field is whether humans generate a protective adaptive immune response to infection. We developed a bacterial challenge murine assay that directly assesses the protective capacity of adoptively transferred human serum samples. We first validated the model by showing that postpneumococcal vaccine serum samples from humans induced effective clearance of Streptococcus pneumoniae in mice. We then found that human serum samples adoptively transferred from children with invasive S. aureus infections exhibited protection from disease in a murine model, with some samples conferring near complete protection. These findings demonstrate that human serum samples are capable of conferring a protective adaptive response generated by humans during invasive staphylococcal disease, allowing for the study of protective factors in a murine model. Identification of the protective factors present in the most efficacious serum samples would be of high interest as potential staphylococcal vaccine candidates or passive therapeutics.
Collapse
Affiliation(s)
- Chih-Ming Tsai
- Department of Pediatrics, Division of Infectious Diseases, University of California, San Diego, California, USA
| | - Nicole Soper
- Department of Pediatrics, Division of Infectious Diseases, Vanderbilt University Medical Center, Nashville, Tennessee, USA
| | - Monique Bennett
- Department of Pediatrics, Division of Infectious Diseases, Vanderbilt University Medical Center, Nashville, Tennessee, USA
| | - Jonathan K Fallon
- Ragon Institute of MGH, MIT, and Harvard, Cambridge, Massachusetts, USA
| | - Ashlin R Michell
- Ragon Institute of MGH, MIT, and Harvard, Cambridge, Massachusetts, USA
| | - Galit Alter
- Ragon Institute of MGH, MIT, and Harvard, Cambridge, Massachusetts, USA
| | - George Y Liu
- Department of Pediatrics, Division of Infectious Diseases, University of California, San Diego, California, USA
| | - Isaac Thomsen
- Department of Pediatrics, Division of Infectious Diseases, Vanderbilt University Medical Center, Nashville, Tennessee, USA
| |
Collapse
|
3
|
Miller LS, Fowler VG, Shukla SK, Rose WE, Proctor RA. Development of a vaccine against Staphylococcus aureus invasive infections: Evidence based on human immunity, genetics and bacterial evasion mechanisms. FEMS Microbiol Rev 2020; 44:123-153. [PMID: 31841134 PMCID: PMC7053580 DOI: 10.1093/femsre/fuz030] [Citation(s) in RCA: 132] [Impact Index Per Article: 33.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2019] [Accepted: 12/13/2019] [Indexed: 12/12/2022] Open
Abstract
Invasive Staphylococcus aureus infections are a leading cause of morbidity and mortality in both hospital and community settings, especially with the widespread emergence of virulent and multi-drug resistant methicillin-resistant S. aureus strains. There is an urgent and unmet clinical need for non-antibiotic immune-based approaches to treat these infections as the increasing antibiotic resistance is creating a serious threat to public health. However, all vaccination attempts aimed at preventing S. aureus invasive infections have failed in human trials, especially all vaccines aimed at generating high titers of opsonic antibodies against S. aureus surface antigens to facilitate antibody-mediated bacterial clearance. In this review, we summarize the data from humans regarding the immune responses that protect against invasive S. aureus infections as well as host genetic factors and bacterial evasion mechanisms, which are important to consider for the future development of effective and successful vaccines and immunotherapies against invasive S. aureus infections in humans. The evidence presented form the basis for a hypothesis that staphylococcal toxins (including superantigens and pore-forming toxins) are important virulence factors, and targeting the neutralization of these toxins are more likely to provide a therapeutic benefit in contrast to prior vaccine attempts to generate antibodies to facilitate opsonophagocytosis.
Collapse
Affiliation(s)
- Lloyd S Miller
- Immunology, Janssen Research and Development, 1400 McKean Road, Spring House, PA, 19477, USA.,Department of Dermatology, Johns Hopkins University School of Medicine, 1550 Orleans Street, Cancer Research Building 2, Suite 209, Baltimore, MD, 21231, USA.,Department of Medicine, Division of Infectious Diseases, Johns Hopkins University School of Medicine, 1830 East Monument Street, Baltimore, MD, 21287, USA.,Department of Orthopaedic Surgery, Johns Hopkins University School of Medicine, 601 North Caroline Street, Baltimore, MD, 21287, USA.,Department of Materials Science and Engineering, Johns Hopkins University, 3400 North Charles Street, Baltimore, MD, 21218, USA
| | - Vance G Fowler
- Department of Medicine, Division of Infectious Diseases, Duke University Medical Center, 315 Trent Drive, Hanes House, Durham, NC, 27710, USA.,Duke Clinical Research Institute, Duke University Medical Center, 40 Duke Medicine Circle, Durham, NC, 27710, USA
| | - Sanjay K Shukla
- Center for Precision Medicine Research, Marshfield Clinic Research Institute, 1000 North Oak Avenue, Marshfield, WI, 54449, USA.,Computation and Informatics in Biology and Medicine, University of Wisconsin, 425 Henry Mall, Room 3445, Madison, WI, 53706, USA
| | - Warren E Rose
- Department of Medicine, University of Wisconsin-Madison School of Medicine and Public Health, 1685 Highland Avenue, 5158 Medical Foundation Centennial Building, Madison, WI, 53705, USA.,Pharmacy Practice Division, University of Wisconsin-Madison, 777 Highland Avenue, 4123 Rennebohm Hall, Madison, WI, 53705 USA
| | - Richard A Proctor
- Department of Medicine, University of Wisconsin-Madison School of Medicine and Public Health, 1685 Highland Avenue, 5158 Medical Foundation Centennial Building, Madison, WI, 53705, USA.,Department of Medical Microbiology and Immunology, University of Wisconsin-Madison School of Medicine and Public Health, 1550 Linden Drive, Microbial Sciences Building, Room 1334, Madison, WI, 53705, USA
| |
Collapse
|
4
|
Silence as a way of niche adaptation: mecC-MRSA with variations in the accessory gene regulator (agr) functionality express kaleidoscopic phenotypes. Sci Rep 2020; 10:14787. [PMID: 32901059 PMCID: PMC7479134 DOI: 10.1038/s41598-020-71640-4] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2019] [Accepted: 08/19/2020] [Indexed: 11/09/2022] Open
Abstract
Functionality of the accessory gene regulator (agr) quorum sensing system is an important factor promoting either acute or chronic infections by the notorious opportunistic human and veterinary pathogen Staphylococcus aureus. Spontaneous alterations of the agr system are known to frequently occur in human healthcare-associated S. aureus lineages. However, data on agr integrity and function are sparse regarding other major clonal lineages. Here we report on the agr system functionality and activity level in mecC-carrying methicillin resistant S. aureus (MRSA) of various animal origins (n = 33) obtained in Europe as well as in closely related human isolates (n = 12). Whole genome analysis assigned all isolates to four clonal complexes (CC) with distinct agr types (CC599 agr I, CC49 agr II, CC130 agr III and CC1943 agr IV). Agr functionality was assessed by a combination of phenotypic assays and proteome analysis. In each CC, isolates with varying agr activity levels were detected, including the presence of completely non-functional variants. Genomic comparison of the agr I-IV encoding regions associated these phenotypic differences with variations in the agrA and agrC genes. The genomic changes were detected independently in divergent lineages, suggesting that agr variation might foster viability and adaptation of emerging MRSA lineages to distinct ecological niches.
Collapse
|
5
|
Bennett MR, Thomsen IP. Epidemiological and Clinical Evidence for the Role of Toxins in S. aureus Human Disease. Toxins (Basel) 2020; 12:toxins12060408. [PMID: 32575633 PMCID: PMC7354447 DOI: 10.3390/toxins12060408] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2020] [Revised: 06/12/2020] [Accepted: 06/15/2020] [Indexed: 12/21/2022] Open
Abstract
Staphylococcus aureus asymptomatically colonizes approximately 30–50% of the population and is a leading cause of bacteremia, bone/joint infections, and skin infections in the US. S. aureus has become a major public health threat due to antibiotic resistance and an increasing number of failed vaccine attempts. To develop new anti-staphylococcal preventive therapies, it will take a more thorough understanding of the current role S. aureus virulence factors play in contributing to human disease. This review focuses on the clinical association of individual toxins with S. aureus infection as well as attempted treatment options. Further understanding of these associations will increase understanding of toxins and their importance to S. aureus pathogenesis.
Collapse
Affiliation(s)
- Monique R. Bennett
- Department of Pediatrics, Vanderbilt University School of Medicine, Nashville, TN 37232, USA;
- Vanderbilt Vaccine Research Program, Nashville, TN 37232, USA
- Vanderbilt Institute for Infection, Immunology and Inflammation, Vanderbilt University Medical Center, Nashville, TN 37232, USA
| | - Isaac P. Thomsen
- Department of Pediatrics, Vanderbilt University School of Medicine, Nashville, TN 37232, USA;
- Vanderbilt Vaccine Research Program, Nashville, TN 37232, USA
- Vanderbilt Institute for Infection, Immunology and Inflammation, Vanderbilt University Medical Center, Nashville, TN 37232, USA
- Correspondence:
| |
Collapse
|
6
|
Lange J, Heidenreich K, Higelin K, Dyck K, Marx V, Reichel C, van Wamel W, den Reijer M, Görlich D, Kahl BC. Staphylococcus aureus Pathogenicity in Cystic Fibrosis Patients-Results from an Observational Prospective Multicenter Study Concerning Virulence Genes, Phylogeny, and Gene Plasticity. Toxins (Basel) 2020; 12:toxins12050279. [PMID: 32357453 PMCID: PMC7290773 DOI: 10.3390/toxins12050279] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2020] [Revised: 04/16/2020] [Accepted: 04/21/2020] [Indexed: 12/04/2022] Open
Abstract
Staphylococcus aureus and cystic fibrosis (CF) are closely interlinked. To date, however, the impact of S. aureus culture in CF airways on lung function and disease progression has only been elucidated to a limited degree. This analysis aims to identify bacterial factors associated to clinical deterioration. Data were collected during an observational prospective multi-center study following 195 patients from 17 centers. The average follow-up time was 80 weeks. S. aureus isolates (n = 3180) were scanned for the presence of 25 virulence genes and agr-types using single and multiplex PCR. The presence of specific virulence genes was not associated to clinical deterioration. For the agr-types 1 and 4, however, a link to the subjects’ clinical status became evident. Furthermore, a significant longitudinal decrease in the virulence gene quantity was observed. Analyses of the plasticity of the virulence genes revealed significantly increased plasticity rates in the presence of environmental stress. The results suggest that the phylogenetic background defines S. aureus pathogenicity rather than specific virulence genes. The longitudinal loss of virulence genes most likely reflects the adaptation process directed towards a persistent and colonizing rather than infecting lifestyle.
Collapse
Affiliation(s)
- Jonas Lange
- Institute of Medical Microbiology, University Hospital Münster, 48149 Münster, Germany; (J.L.); (K.H.); (K.H.); (K.D.); (V.M.); (C.R.)
| | - Kathrin Heidenreich
- Institute of Medical Microbiology, University Hospital Münster, 48149 Münster, Germany; (J.L.); (K.H.); (K.H.); (K.D.); (V.M.); (C.R.)
| | - Katharina Higelin
- Institute of Medical Microbiology, University Hospital Münster, 48149 Münster, Germany; (J.L.); (K.H.); (K.H.); (K.D.); (V.M.); (C.R.)
| | - Kristina Dyck
- Institute of Medical Microbiology, University Hospital Münster, 48149 Münster, Germany; (J.L.); (K.H.); (K.H.); (K.D.); (V.M.); (C.R.)
| | - Vanessa Marx
- Institute of Medical Microbiology, University Hospital Münster, 48149 Münster, Germany; (J.L.); (K.H.); (K.H.); (K.D.); (V.M.); (C.R.)
| | - Christian Reichel
- Institute of Medical Microbiology, University Hospital Münster, 48149 Münster, Germany; (J.L.); (K.H.); (K.H.); (K.D.); (V.M.); (C.R.)
| | - Willem van Wamel
- Department of Medical Microbiology and Infectious Diseases, Erasmus Medical Center Rotterdam, 3015 CN Rotterdam, The Netherlands; (W.v.W.); (M.d.R.)
| | - Martijn den Reijer
- Department of Medical Microbiology and Infectious Diseases, Erasmus Medical Center Rotterdam, 3015 CN Rotterdam, The Netherlands; (W.v.W.); (M.d.R.)
| | - Dennis Görlich
- Institute of Biostatistics and Clinical Research, University Hospital Münster, 48149 Münster, Germany;
| | - Barbara C. Kahl
- Institute of Medical Microbiology, University Hospital Münster, 48149 Münster, Germany; (J.L.); (K.H.); (K.H.); (K.D.); (V.M.); (C.R.)
- Correspondence: ; Tel.: +49-251-8355358
| |
Collapse
|
7
|
Tam K, Torres VJ. Staphylococcus aureus Secreted Toxins and Extracellular Enzymes. Microbiol Spectr 2019; 7:10.1128/microbiolspec.GPP3-0039-2018. [PMID: 30873936 PMCID: PMC6422052 DOI: 10.1128/microbiolspec.gpp3-0039-2018] [Citation(s) in RCA: 192] [Impact Index Per Article: 38.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2018] [Indexed: 02/06/2023] Open
Abstract
Staphylococcus aureus is a formidable pathogen capable of causing infections in different sites of the body in a variety of vertebrate animals, including humans and livestock. A major contribution to the success of S. aureus as a pathogen is the plethora of virulence factors that manipulate the host's innate and adaptive immune responses. Many of these immune modulating virulence factors are secreted toxins, cofactors for activating host zymogens, and exoenzymes. Secreted toxins such as pore-forming toxins and superantigens are highly inflammatory and can cause leukocyte cell death by cytolysis and clonal deletion, respectively. Coagulases and staphylokinases are cofactors that hijack the host's coagulation system. Exoenzymes, including nucleases and proteases, cleave and inactivate various immune defense and surveillance molecules, such as complement factors, antimicrobial peptides, and surface receptors that are important for leukocyte chemotaxis. Additionally, some of these secreted toxins and exoenzymes can cause disruption of endothelial and epithelial barriers through cell lysis and cleavage of junction proteins. A unique feature when examining the repertoire of S. aureus secreted virulence factors is the apparent functional redundancy exhibited by the majority of the toxins and exoenzymes. However, closer examination of each virulence factor revealed that each has unique properties that have important functional consequences. This chapter provides a brief overview of our current understanding of the major secreted virulence factors critical for S. aureus pathogenesis.
Collapse
Affiliation(s)
- Kayan Tam
- Department of Microbiology, New York University School of Medicine, Alexandria Center for Life Science, New York, NY 10016
| | - Victor J Torres
- Department of Microbiology, New York University School of Medicine, Alexandria Center for Life Science, New York, NY 10016
| |
Collapse
|
8
|
Affiliation(s)
- Isaac P Thomsen
- a Department of Pediatrics , Division of Pediatric Infectious Diseases and the Vanderbilt Vaccine Research Program, Vanderbilt University Medical Center , Nashville , Tennessee , USA
| |
Collapse
|
9
|
Wood JB, Jones LS, Soper NR, Xu M, Torres VJ, Buddy Creech C, Thomsen IP. Serologic Detection of Antibodies Targeting the Leukocidin LukAB Strongly Predicts Staphylococcus aureus in Children With Invasive Infection. J Pediatric Infect Dis Soc 2018. [PMID: 29538707 PMCID: PMC6510946 DOI: 10.1093/jpids/piy017] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
BACKGROUND Staphylococcus aureus is among the most commonly identified causes of invasive bacterial infection in children; however, reliable results from cultures of sterile-site samples often cannot be obtained, which necessitates prescription of a broad empiric antimicrobial agent(s). Children with invasive S aureus infection rapidly generate high antibody titers to the cytotoxin LukAB; therefore, the aim of this study was to assess the diagnostic utility of an anti-LukAB antibody assay for children with musculoskeletal infection (MSKI). METHODS We conducted a 2-year prospective study of all eligible children admitted to Vanderbilt Children's Hospital with an MSKI. Acute and convalescent sera were obtained, and antibodies that target LukAB were measured by an enzyme-linked immunosorbent assay. RESULTS Forty-two children were enrolled. The median concentrations of LukAB antibodies for children with S aureus infection were 130.3 U/mL in the acute phase and 455 U/mL in the convalescent phase (P < .001). The median concentrations of LukAB antibodies in children with a non-S aureus MSKI were 8.6 U/mL in the acute phase and 9.7 U/mL in the convalescent phase. The assay discriminated between S aureus and non-S aureus infection with areas under the receiver operating characteristic curve of 0.81 (95% confidence interval, 0.67-0.95; P < .001) and 0.95 (95% confidence interval, 0.86-1; P < .001) for samples tested in the acute and follow-up periods, respectively. With no false-negative results, the assay accurately ruled out S aureus in samples obtained during the convalescent phase. CONCLUSION Culture-independent diagnostics have the potential to improve care by narrowing antimicrobial therapy on the basis of the likelihood of S aureus infection. The results of this proof-of-concept study suggest that a LukAB serologic assay might be useful in the diagnosis of invasive bacterial infections, and larger-scale validation studies are warranted.
Collapse
Affiliation(s)
- James B Wood
- Division of Pediatric Infectious Diseases, Department of Pediatrics, Nashville, Tennessee,Correspondence: J. B. Wood, Vanderbilt University Medical Center, Division of Pediatric Infectious Diseases, 1161 21st Ave South, D-7235 MCN, Nashville, TN 37232 ()
| | - Lauren S Jones
- Division of Pediatric Infectious Diseases, Department of Pediatrics, Nashville, Tennessee
| | - Nicole R Soper
- Division of Pediatric Infectious Diseases, Department of Pediatrics, Nashville, Tennessee
| | - Meng Xu
- Department of Biostatistics, Vanderbilt University School of Medicine, Nashville, Tennessee
| | - Victor J Torres
- Department of Microbiology, New York University School of Medicine, New York
| | - C Buddy Creech
- Division of Pediatric Infectious Diseases, Department of Pediatrics, Nashville, Tennessee
| | - Isaac P Thomsen
- Division of Pediatric Infectious Diseases, Department of Pediatrics, Nashville, Tennessee
| |
Collapse
|
10
|
Commercial Intravenous Immunoglobulin Preparations Contain Functional Neutralizing Antibodies against the Staphylococcus aureus Leukocidin LukAB (LukGH). Antimicrob Agents Chemother 2017; 61:AAC.00968-17. [PMID: 28874371 DOI: 10.1128/aac.00968-17] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2017] [Accepted: 08/26/2017] [Indexed: 11/20/2022] Open
Abstract
The pathogenesis of Staphylococcus aureus is mediated by an array of important virulence factors, including the two-component leukocidin family of toxins. LukAB (also known as LukGH), the most recently discovered leukocidin, is potently lethal to phagocytes, produced during invasive human disease, and present in all known clinical isolates of S. aureus Intravenous immunoglobulin (IVIg) is often used clinically in severe S. aureus infections. The primary aim of this study was to assess the binding and neutralization potential of IVIg against LukAB. A secondary aim was to examine the lot-to-lot variability of IVIg in the binding and neutralization of LukAB. We studied 24 distinct lots of IVIg and compared them to serum from children with invasive S. aureus infection (in the acute and convalescent phases) and from healthy, uninfected controls. We found that all lots of IVIg contained functional antibodies targeting LukAB. After adjusting for total antibody content per sample, we found that the amount of anti-LukAB antibody in IVIg was similar to that seen with healthy controls and less than that seen with patients with invasive S. aureus infection. IVIg samples had lower neutralization capacity than samples from healthy controls and children with invasive infection. IVIg had remarkably little lot-to-lot variation in LukAB binding but had significantly more variation in toxin neutralization. These results represent the first report of functional antibodies against the important S. aureus leukocidin LukAB in IVIg. Given the frequent clinical use of IVIg for severe S. aureus infections, improving our understanding of functional antibody properties exhibited by this therapeutic is essential.
Collapse
|
11
|
Thomsen IP, Sapparapu G, James DBA, Cassat JE, Nagarsheth M, Kose N, Putnam N, Boguslawski KM, Jones LS, Wood JB, Creech CB, Torres VJ, Crowe JE. Monoclonal Antibodies Against the Staphylococcus aureus Bicomponent Leukotoxin AB Isolated Following Invasive Human Infection Reveal Diverse Binding and Modes of Action. J Infect Dis 2017; 215:1124-1131. [PMID: 28186295 PMCID: PMC5426380 DOI: 10.1093/infdis/jix071] [Citation(s) in RCA: 63] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2016] [Accepted: 01/30/2017] [Indexed: 12/15/2022] Open
Abstract
The 2-component leukotoxin LukAB is critical for Staphylococcus aureus targeting and killing of human neutrophils ex vivo and is produced in the setting of human infection. We report 3 LukAB-specific human monoclonal antibodies (mAbs) with distinct mechanisms of toxin neutralization and in vivo efficacy. Three hybridomas secreting mAbs with anti-LukAB activity (designated SA-13, -15, and -17) were generated from B cells obtained from a 12-year-old boy with S. aureus osteomyelitis. Each of the 3 mAbs neutralized LukAB-mediated neutrophil toxicity, exhibited differing levels of potency, recognized different antigenic sites on the toxin, and displayed at least 2 distinct mechanisms for cytotoxic inhibition. SA-15 bound exclusively to the dimeric form of the toxin, suggesting that human B cells recognize epitopes on the dimerized form of LukAB during natural infection. Both SA-13 and SA-17 bound the LukA monomer and the LukAB dimer. Although all 3 mAbs potently neutralized cytotoxicity, only SA-15 and SA-17 significantly inhibited toxin association with the cell surface. Treatment with a 1:1 mixture of mAbs SA-15 and SA-17 resulted in significantly lower bacterial colony counts in heart, liver, and kidneys in a murine model of S. aureus sepsis. These data describe the isolation of diverse and efficacious antitoxin mAbs.
Collapse
Affiliation(s)
| | | | - David B A James
- Department of Microbiology, New York University School of Medicine, New York, New York
| | - James E Cassat
- Department of Pediatrics
- Department of Pathology, Microbiology and Immunology, Vanderbilt University Medical Center, Nashville, Tennessee ; and
| | | | | | - Nicole Putnam
- Department of Pathology, Microbiology and Immunology, Vanderbilt University Medical Center, Nashville, Tennessee; and
| | | | | | | | | | - Victor J Torres
- Department of Microbiology, New York University School of Medicine, New York, New York
| | - James E Crowe
- Department of Pediatrics
- Vanderbilt Vaccine Center, and
- Department of Pathology, Microbiology and Immunology, Vanderbilt University Medical Center, Nashville, Tennessee ; and
| |
Collapse
|
12
|
Junge S, Görlich D, den Reijer M, Wiedemann B, Tümmler B, Ellemunter H, Dübbers A, Küster P, Ballmann M, Koerner-Rettberg C, Große-Onnebrink J, Heuer E, Sextro W, Mainz JG, Hammermann J, Riethmüller J, Graepler-Mainka U, Staab D, Wollschläger B, Szczepanski R, Schuster A, Tegtmeyer FK, Sutharsan S, Wald A, Nofer JR, van Wamel W, Becker K, Peters G, Kahl BC. Factors Associated with Worse Lung Function in Cystic Fibrosis Patients with Persistent Staphylococcus aureus. PLoS One 2016; 11:e0166220. [PMID: 27861524 PMCID: PMC5115705 DOI: 10.1371/journal.pone.0166220] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2016] [Accepted: 10/25/2016] [Indexed: 01/04/2023] Open
Abstract
Background Staphylococcus aureus is an important pathogen in cystic fibrosis (CF). However, it is not clear which factors are associated with worse lung function in patients with persistent S. aureus airway cultures. Our main hypothesis was that patients with high S. aureus density in their respiratory specimens would more likely experience worsening of their lung disease than patients with low bacterial loads. Methods Therefore, we conducted an observational prospective longitudinal multi-center study and assessed the association between lung function and S. aureus bacterial density in respiratory samples, co-infection with other CF-pathogens, nasal S. aureus carriage, clinical status, antibiotic therapy, IL-6- and IgG-levels against S. aureus virulence factors. Results 195 patients from 17 centers were followed; each patient had an average of 7 visits. Data were analyzed using descriptive statistics and generalized linear mixed models. Our main hypothesis was only supported for patients providing throat specimens indicating that patients with higher density experienced a steeper lung function decline (p<0.001). Patients with exacerbations (n = 60), S. aureus small-colony variants (SCVs, n = 84) and co-infection with Stenotrophomonas maltophilia (n = 44) had worse lung function (p = 0.0068; p = 0.0011; p = 0.0103). Patients with SCVs were older (p = 0.0066) and more often treated with trimethoprim/sulfamethoxazole (p = 0.0078). IL-6 levels positively correlated with decreased lung function (p<0.001), S. aureus density in sputa (p = 0.0016), SCVs (p = 0.0209), exacerbations (p = 0.0041) and co-infections with S. maltophilia (p = 0.0195) or A. fumigatus (p = 0.0496). Conclusions In CF-patients with chronic S. aureus cultures, independent risk factors for worse lung function are high bacterial density in throat cultures, exacerbations, elevated IL-6 levels, presence of S. aureus SCVs and co-infection with S. maltophilia. Trial Registration ClinicalTrials.gov NCT00669760
Collapse
Affiliation(s)
- Sibylle Junge
- Clinic for Paediatric Pulmonology, Allergology and Neonatology, Hannover, Hannover, Germany
| | - Dennis Görlich
- Institute of Biostatistics and Clinical Research, University Hospital Münster, Münster, Germany
| | - Martijn den Reijer
- Department of Medical Microbiology and Infectious Diseases, Erasmus Medical Center Rotterdam, Rotterdam, The Netherlands
| | - Bärbel Wiedemann
- Institute of Medical Informatics and Biometrics, Technical University Dresden, Dresden, Germany
| | - Burkhard Tümmler
- Clinical Research Group, Clinic for Paediatric Pulmonology, Allergology and Neonatology, Medizinische Hochschule Hannover, Hannover, Germany
| | - Helmut Ellemunter
- CF-Center Innsbruck, Department of Child and Adolescent Health, Medical University of Innsbruck, Innsbruck, Austria
| | - Angelika Dübbers
- Department of Paediatrics, University Hospital Münster, Münster, Germany
| | - Peter Küster
- Department of Paediatrics, Clemenshospital Münster, Münster, Germany
| | - Manfred Ballmann
- Ruhr University, Paediatric Clinic at St Josef Hospital, Bochum, Germany
| | | | | | | | | | - Jochen G. Mainz
- CF Center, Department of Paediatrics, Jena University Hospital, Jena, Germany
| | - Jutta Hammermann
- Department of Paediatrics, University Clinics Dresden, Dresden, Germany
| | | | | | - Doris Staab
- Department of Paediatric Pulmonology and Immunology, Charité Universitätsmedizin Berlin, Campus Virchow Klinikum, Berlin, Germany
| | | | | | - Antje Schuster
- Department of Paediatrics, University of Düsseldorf, Düsseldorf, Germany
| | | | | | | | - Jerzy-Roch Nofer
- Center for Laboratory Medicine, University Hospital Münster, Münster, Germany
| | - Willem van Wamel
- Department of Medical Microbiology and Infectious Diseases, Erasmus Medical Center Rotterdam, Rotterdam, The Netherlands
| | - Karsten Becker
- Institute of Medical Microbiology, University Hospital Münster, Münster, Germany
| | - Georg Peters
- Institute of Medical Microbiology, University Hospital Münster, Münster, Germany
| | - Barbara C. Kahl
- Institute of Medical Microbiology, University Hospital Münster, Münster, Germany
- * E-mail:
| |
Collapse
|