1
|
Hayes K, Cotter L, O'Halloran F. In vitro synergistic activity of erythromycin and nisin against clinical Group B Streptococcus isolates. J Appl Microbiol 2019; 127:1381-1390. [PMID: 31342602 DOI: 10.1111/jam.14400] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2019] [Revised: 07/04/2019] [Accepted: 07/18/2019] [Indexed: 12/12/2022]
Abstract
AIMS This study investigated the potential synergy between erythromycin and nisin against clinical Group B Streptococcus (GBS) strains. METHODS AND RESULTS The combination of erythromycin and nisin was examined for synergistic activity using checkerboard and time-kill assays against invasive and colonizing GBS strains. Additionally, the immunological effect of the antibiotic combination was investigated in vitro using human U937 cells and ELISA analysis. Checkerboard assays confirmed an additive effect when the antimicrobials were combined, while time-kill assays demonstrated a synergistic effect when antimicrobials were combined for invasive GBS isolates. Furthermore, a significantly lower TNF-alpha response (P < 0·05) was observed in U937 cells challenged with GBS when erythromycin and nisin were used in combination. CONCLUSIONS The results suggest that erythromycin and nisin can act synergistically to inhibit the growth of GBS. SIGNIFICANCE AND IMPACT OF THE STUDY Group B Streptococcus is the leading cause of invasive neonatal disease worldwide and is becoming increasingly more prevalent in adults. Resistance to some conventionally used antibiotics, such as erythromycin and clindamycin, continue to rise among GBS, indicating a need for alternative treatments. This study demonstrates the potential of an erythromycin-nisin combination for treatment of GBS infections and encourages further investigation of this treatment option.
Collapse
Affiliation(s)
- K Hayes
- Department of Biological Sciences, Cork Institute of Technology, Bishopstown, Cork, Ireland
| | - L Cotter
- Department of Biological Sciences, Cork Institute of Technology, Bishopstown, Cork, Ireland
| | - F O'Halloran
- Department of Biological Sciences, Cork Institute of Technology, Bishopstown, Cork, Ireland
| |
Collapse
|
2
|
Combination therapy with ampicillin and azithromycin improved outcomes in a mouse model of group B streptococcal sepsis. PLoS One 2017; 12:e0182023. [PMID: 28759625 PMCID: PMC5536305 DOI: 10.1371/journal.pone.0182023] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2016] [Accepted: 07/11/2017] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND Evidence suggests that β-lactam monotherapy of streptococcal infections may incite stronger inflammation and is inferior to combination therapy with macrolides. We hypothesized that use of macrolides alone or in combination with a β-lactam for group B streptococcal (GBS) sepsis would improve outcomes by reducing inflammation. METHODS TNF-α was measured from supernatants of RAW 264.7 cells stimulated with GBS isolates, in presence of four treatment regimens: ampicillin alone, azithromycin alone, or combination of azithromycin plus ampicillin. Mouse model of GBS sepsis was developed and treated with same four regimens. Clinical sepsis scores were monitored; serum cytokines (TNF-α, IL-6, IL-10) and chemokines (MIP-1α) were measured at the end. RESULTS GBS isolates exposed to azithromycin or combination (compared to ampicillin alone) stimulated less TNF production in vitro. In the murine sepsis model, mortality was lower along with decreased sepsis scores in mice treated with combination therapy. Mean serum IL-6 was lower in mice treated with azithromycin alone (66±52 pg/ml) or combination of ampicillin plus azithromycin (52±22 pg/ml) compared to ampicillin alone (260±160 pg/ml) (p<0.005). CONCLUSIONS Combination therapy of ampicillin+azithromycin improved outcomes in a murine GBS sepsis model; this therapeutic approach deserves additional study.
Collapse
|
3
|
Upadhyay K, Park JE, Yoon TW, Halder P, Kim YI, Metcalfe V, Talati AJ, English BK, Yi AK. Group B Streptococci Induce Proinflammatory Responses via a Protein Kinase D1-Dependent Pathway. THE JOURNAL OF IMMUNOLOGY 2017; 198:4448-4457. [PMID: 28461572 DOI: 10.4049/jimmunol.1601089] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/22/2016] [Accepted: 04/02/2017] [Indexed: 12/31/2022]
Abstract
Group B streptococci (GBS) are one of the leading causes of life-threatening illness in neonates. Proinflammatory responses to GBS mediated through host innate immune receptors play a critical role in the disease manifestation. However, the mechanisms involved in proinflammatory responses against GBS, as well as the contribution of signaling modulators involved in host immune defense, have not been fully elucidated. In the present study, we investigated the role of protein kinase D (PKD)1 in the proinflammatory responses to GBS. We found that both live and antibiotic-killed GBS induce activation of PKD1 through a pathway that is dependent on the TLR signaling adaptor MyD88 and its downstream kinase IL-1R-associated kinase 1, but independent of TNFR-associated factor 6. Our studies using pharmacological PKD inhibitors and PKD1-knockdown macrophages revealed that PKD1 is indispensable for GBS-mediated activation of MAPKs and NF-κB and subsequent expression of proinflammatory mediators. Furthermore, systemic administration of a PKD inhibitor protects d-galactosamine-sensitized mice from shock-mediated death caused by antibiotic-killed GBS. These findings imply that PKD1 plays a critical regulatory role in GBS-induced proinflammatory reactions and sepsis, and inhibition of PKD1 activation together with antibiotic treatment in GBS-infected neonates could be an effective way to control GBS diseases.
Collapse
Affiliation(s)
- Kirtikumar Upadhyay
- Department of Pediatrics, The University of Tennessee Health Science Center, Memphis, TN 38163.,Department of Obstetrics and Gynecology, The University of Tennessee Health Science Center, Memphis, TN 38163.,Children's Foundation Research Institute, Le Bonheur Children's Hospital, Memphis, TN 38103
| | - Jeoung-Eun Park
- Department of Pediatrics, The University of Tennessee Health Science Center, Memphis, TN 38163
| | - Tae Won Yoon
- Department of Microbiology, Immunology and Biochemistry, The University of Tennessee Health Science Center, Memphis, TN 38163; and
| | - Priyanka Halder
- Department of Microbiology, Immunology and Biochemistry, The University of Tennessee Health Science Center, Memphis, TN 38163; and
| | - Young-In Kim
- Department of Pediatrics, The University of Tennessee Health Science Center, Memphis, TN 38163.,Children's Foundation Research Institute, Le Bonheur Children's Hospital, Memphis, TN 38103
| | - Victoria Metcalfe
- Department of Microbiology, Immunology and Biochemistry, The University of Tennessee Health Science Center, Memphis, TN 38163; and
| | - Ajay J Talati
- Department of Pediatrics, The University of Tennessee Health Science Center, Memphis, TN 38163.,Department of Obstetrics and Gynecology, The University of Tennessee Health Science Center, Memphis, TN 38163.,Children's Foundation Research Institute, Le Bonheur Children's Hospital, Memphis, TN 38103
| | - B Keith English
- Department of Pediatrics and Human Development, Michigan State University, Lansing, MI 48912
| | - Ae-Kyung Yi
- Department of Microbiology, Immunology and Biochemistry, The University of Tennessee Health Science Center, Memphis, TN 38163; and
| |
Collapse
|
4
|
Ingram K, Marker M, Meals E, Talati AJ, Spentzas T, English BK. Azithromycin Inhibits Macrophage Tumor Necrosis Factor Secretion in Response to Both Azithromycin-Susceptible and Azithromycin-Resistant Pneumococci. J Pediatric Infect Dis Soc 2014; 3:168-71. [PMID: 26625370 DOI: 10.1093/jpids/pit014] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/04/2012] [Accepted: 01/29/2013] [Indexed: 11/13/2022]
Abstract
We studied the effect of azithromycin (AZM) on macrophage responses to pneumococci. We found that exposure of pneumococci to AZM led to reduced tumor necrosis factor (TNF) secretion by macrophages; this effect was observed in response to both AZM-susceptible and AZM-resistant (AZM-R) pneumococci.
Collapse
Affiliation(s)
- Kim Ingram
- Children's Foundation Research Institute at Le Bonheur Children's Hospital; Divisions of Pediatric Critical Care Medicine
| | - Matthew Marker
- Children's Foundation Research Institute at Le Bonheur Children's Hospital; Divisions of
| | - Elizabeth Meals
- Children's Foundation Research Institute at Le Bonheur Children's Hospital; Divisions of
| | - Ajay J Talati
- Children's Foundation Research Institute at Le Bonheur Children's Hospital; Divisions of Neonatology
| | - Thomas Spentzas
- Children's Foundation Research Institute at Le Bonheur Children's Hospital; Divisions of Pediatric Critical Care Medicine Department of Preventive Medicine, University of Tennessee Health Science Center, Memphis
| | - B Keith English
- Children's Foundation Research Institute at Le Bonheur Children's Hospital; Divisions of Pediatric Infectious Diseases, Department of Pediatrics
| |
Collapse
|
5
|
Vancomycin-rifampin combination therapy has enhanced efficacy against an experimental Staphylococcus aureus prosthetic joint infection. Antimicrob Agents Chemother 2013; 57:5080-6. [PMID: 23917317 DOI: 10.1128/aac.00702-13] [Citation(s) in RCA: 62] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023] Open
Abstract
Treatment of prosthetic joint infections often involves a two-stage exchange, with implant removal and antibiotic spacer placement followed by systemic antibiotic therapy and delayed reimplantation. However, if antibiotic therapy can be improved, one-stage exchange or implant retention may be more feasible, thereby decreasing morbidity and preserving function. In this study, a mouse model of prosthetic joint infection was used in which Staphylococcus aureus was inoculated into a knee joint containing a surgically placed metallic implant extending from the femur. This model was used to evaluate whether combination therapy of vancomycin plus rifampin has increased efficacy compared with vancomycin alone against these infections. On postoperative day 7, vancomycin with or without rifampin was administered for 6 weeks with implant retention. In vivo bioluminescence imaging, ex vivo CFU enumeration, X-ray imaging, and histologic analysis were carried out. We found that there was a marked therapeutic benefit when vancomycin was combined with rifampin compared with vancomycin alone. Taken together, our results suggest that the mouse model used could serve as a valuable in vivo preclinical model system to evaluate and compare efficacies of antibiotics and combinatory therapy for prosthetic joint infections before more extensive studies are carried out in human subjects.
Collapse
|
6
|
Bi W, Jing X, Zhu L, Liang Y, Liu J, Yang L, Xiao S, Xu A, Shi Q, Tao E. Inhibition of 26S protease regulatory subunit 7 (MSS1) suppresses neuroinflammation. PLoS One 2012; 7:e36142. [PMID: 22629310 PMCID: PMC3356363 DOI: 10.1371/journal.pone.0036142] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2011] [Accepted: 03/26/2012] [Indexed: 11/18/2022] Open
Abstract
Recently, researchers have focused on immunosuppression induced by rifampicin. Our previous investigation found that rifampicin was neuroprotective by inhibiting the production of pro-inflammatory mediators, thereby suppressing microglial activation. In this study, using 2-dimensional gel electrophoresis (2-DE) and mass spectrometry (MS), we discovered that 26S protease regulatory subunit 7 (MSS1) was decreased in rifampicin-treated microglia. Western blot analysis verified the downregulation of MSS1 expression by rifampicin. As it is indicated that the modulation of the ubiquitin-26S proteasome system (UPS) with proteasome inhibitors is efficacious for the treatment of neuro-inflammatory disorders, we next hypothesized that silencing MSS1 gene expression might inhibit microglial inflammation. Using RNA interference (RNAi), we showed significant reduction of IkBα degradation and NF-kB activation. The production of lipopolysaccharides-induced pro-inflammatory mediators such as inducible nitric oxide synthase (iNOS), nitric oxide, cyclooxygenase-2, and prostaglandin E2 were also reduced by MSS1 gene knockdown. Taken together, our findings suggested that rifampicin inhibited microglial inflammation by suppressing MSS1 protein production. Silencing MSS1 gene expression decreased neuroinflammation. We concluded that MSS1 inhibition, in addition to anti-inflammatory rifampicin, might represent a novel mechanism for the treatment of neuroinflammatory disorders.
Collapse
Affiliation(s)
- Wei Bi
- Department of Neurology, Sun Yat-sen Memorial Hospital of Sun Yat-sen University, Guangzhou, People’s Republic of China
- Department of Neurology, First Affiliated Hospital of Jinan University, Guangzhou, People’s Republic of China
| | - Xiuna Jing
- Department of Neurology, Sun Yat-sen Memorial Hospital of Sun Yat-sen University, Guangzhou, People’s Republic of China
| | - Lihong Zhu
- Joint Laboratory for Brain Function and Health of Jinan University and the University of Hong Kong, School of Medicine, Jinan University, Guangzhou, People’s Republic of China
| | - Yanran Liang
- Department of Neurology, Sun Yat-sen Memorial Hospital of Sun Yat-sen University, Guangzhou, People’s Republic of China
| | - Jun Liu
- Department of Neurology, Sun Yat-sen Memorial Hospital of Sun Yat-sen University, Guangzhou, People’s Republic of China
| | - Lianhong Yang
- Department of Neurology, Sun Yat-sen Memorial Hospital of Sun Yat-sen University, Guangzhou, People’s Republic of China
| | - Songhua Xiao
- Department of Neurology, Sun Yat-sen Memorial Hospital of Sun Yat-sen University, Guangzhou, People’s Republic of China
| | - Anding Xu
- Department of Neurology, First Affiliated Hospital of Jinan University, Guangzhou, People’s Republic of China
| | - Qiaoyun Shi
- Division of Cardiovascular Medicine, Center for Inherited Cardiovascular Disease, Stanford University School of Medicine, Stanford, California, United States of America
| | - Enxiang Tao
- Department of Neurology, Sun Yat-sen Memorial Hospital of Sun Yat-sen University, Guangzhou, People’s Republic of China
- * E-mail:
| |
Collapse
|
7
|
Bi W, Zhu L, Wang C, Liang Y, Liu J, Shi Q, Tao E. Rifampicin inhibits microglial inflammation and improves neuron survival against inflammation. Brain Res 2011; 1395:12-20. [PMID: 21555117 DOI: 10.1016/j.brainres.2011.04.019] [Citation(s) in RCA: 67] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2011] [Revised: 04/08/2011] [Accepted: 04/12/2011] [Indexed: 12/21/2022]
Abstract
Microglial activation plays an important role in the pathophysiology of neurodegenerative diseases, and suppression of microglial activation prevents the progression of neurodegeneration. Rifampicin, a bacteriocidal antibiotic, induces immunosuppression. We hypothesized that rifampicin might be neuroprotective by inhibiting the production of pro-inflammatory mediators, thereby suppressing microglial activation. In the present study, we examined the effects of rifampicin on the production of lipopolysaccharide (LPS)-induced pro-inflammatory mediators and their signaling pathways in BV2 microglia. We also assessed the neuroprotective effects of rifampicin using a co-culture of microglia and neurons. Our results showed that rifampicin inhibited the LPS-stimulated expression of inducible nitric oxide synthase, cyclooxygenase-2, tumor necrosis factor-α, and interleukin-1β, as well as the production of nitric oxide and prostaglandin E₂. Moreover, rifampicin suppressed LPS-induced nuclear factor-kappa B activation by blocking the degradation of the inhibitor of the nuclear transcription factor NF-kappa B. Rifampicin inhibited the phosphorylation of mitogen activated protein kinases, although protein kinase B was not inhibited. Preincubation of microglia with rifampicin reduced neurotoxicity and improved neuron survival in a microglia-neuronal co-culture system. Taken together, these findings suggest that rifampicin, with its anti-inflammatory properties, might be a novel treatment for neurodegenerative diseases.
Collapse
Affiliation(s)
- Wei Bi
- Department of Neurology, Sun Yat-sen memorial Hospital, Sun Yat-sen University, Guangzhou 510120, PR China
| | | | | | | | | | | | | |
Collapse
|
8
|
Spentzas T, Kudumula R, Acuna C, Talati AJ, Ingram KC, Savorgnan F, Meals EA, English BK. Role of bacterial components in macrophage activation by the LAC and MW2 strains of community-associated, methicillin-resistant Staphylococcus aureus. Cell Immunol 2011; 269:46-53. [PMID: 21458780 DOI: 10.1016/j.cellimm.2011.03.009] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2010] [Revised: 03/11/2011] [Accepted: 03/11/2011] [Indexed: 10/18/2022]
Abstract
We tested the contribution of four staphylococcal components - PSM-α, PSM-β, δ-toxin, and PVL - in triggering macrophage secretion of tumor necrosis factor (TNF) and interleukins 6 (IL-6) and 12 (IL-12) by two prominent, circulating strains of community-associated, methicillin-resistant Staphylococcus aureus (CA-MRSA): LAC, USA300; MW2, USA400. RAW 264.7 murine macrophages were stimulated with live, antibiotic-exposed bacteria, and cytokine secretion was quantitated in supernatants. Deletion of PSM-α expression in LAC led to >50% reduction in macrophage TNF and IL-6 secretion and a 20% reduction in IL-12 secretion, while PSM-α deletion in MW2 did not significantly reduce macrophage TNF secretion but resulted in a 15-20% reduction in IL-6 and IL-12 secretion. Deletion of δ-toxin in either strain led to more than 50% reduction in macrophage IL-6 secretion and smaller reductions in macrophage TNF and IL-12 secretion (8-25%). Our data implicate both PSM-α and δ-toxin in stimulating macrophage cytokine responses to CA-MRSA bacteria.
Collapse
Affiliation(s)
- Thomas Spentzas
- Department of Pediatrics, University of Tennessee Health Science Center, Memphis, TN, USA
| | | | | | | | | | | | | | | |
Collapse
|
9
|
McCullers JA, English BK. Improving therapeutic strategies for secondary bacterial pneumonia following influenza. Future Microbiol 2008; 3:397-404. [PMID: 18651811 DOI: 10.2217/17460913.3.4.397] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
Secondary bacterial pneumonia following influenza is an old problem, which is re-emerging. Despite rapid advances in our armamentarium of antimicrobials, the case-fatality rate for this frequent complication of influenza remains high. In some settings, common treatment options may actually contribute to poor outcomes, as rapid lysis of pathogenic bacteria on the backdrop of an activated immune system responding to influenza may lead to inflammatory damage in the lung. An understanding of the inter-related contributions of the antecedent viral infection, the invading bacteria and the host immune response is necessary to formulate an appropriate therapeutic approach. Prevention and resolution of these fulminant infections will require new approaches, including alternate treatment strategies, combination therapies targeting several aspects of the pathogenic process and, potentially, immunomodulation. In the not-so-distant future, strategies aimed at disarming pathogens without eliminating them may be more effective than our current treatment paradigms.
Collapse
Affiliation(s)
- Jonathan A McCullers
- Department of Infectious Diseases, St. Jude Children's Research Hospital, 332 N Lauderdale St, Memphis, TN 38105-2794, USA.
| | | |
Collapse
|
10
|
Guay D. Update on clindamycin in the management of bacterial, fungal and protozoal infections. Expert Opin Pharmacother 2007; 8:2401-44. [PMID: 17927492 DOI: 10.1517/14656566.8.14.2401] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Lincomycin and clindamycin are the only members of the relatively small lincosamide antimicrobial class marketed for use in humans. This paper only reviews data regarding clindamycin, with an emphasis on data published over the last decade. Clindamycin exhibits a broad spectrum of antimicrobial activity, including Gram-positive aerobes/anaerobes, Gram-negative anaerobes and select protozoa (Toxoplasma gondii, Plasmodium falciparum, Babesia spp.) and fungi (Pneumocystis jiroveci). It still enjoys use in the therapy and prophylaxis of a large number of bacterial, protozoal and fungal infections, despite > 40 years of clinical use. However, the spectre of resistance by an increasing number of microorganisms is beginning to cast a shadow over the future use of this valuable agent. With the emergence and spread of infections due to community-acquired methicillin-resistant Staphylococci (for which clindamycin is a first-line agent), it is hoped that the issues of resistance can be mitigated and the use of clindamycin extended for at least the foreseeable future.
Collapse
Affiliation(s)
- David Guay
- University of Minnesota, College of Pharmacy, Weaver-Densford Hall 7-148, 308 Harvard Street SE, Minneapolis, MN 55455, USA.
| |
Collapse
|
11
|
Goos M, Zech WD, Jaiswal MK, Balakrishnan S, Ebert S, Mitchell T, Carrì MT, Keller BU, Nau R. Expression of a Cu,Zn superoxide dismutase typical for familial amyotrophic lateral sclerosis increases the vulnerability of neuroblastoma cells to infectious injury. BMC Infect Dis 2007; 7:131. [PMID: 17997855 PMCID: PMC2211486 DOI: 10.1186/1471-2334-7-131] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2007] [Accepted: 11/12/2007] [Indexed: 12/15/2022] Open
Abstract
Background Infections can aggravate the course of neurodegenerative diseases including amyotrophic lateral sclerosis (ALS). Mutations in the anti-oxidant enzyme Cu,Zn superoxide dismutase (EC 1.15.1.1, SOD1) are associated with familial ALS. Streptococcus pneumoniae, the most frequent respiratory pathogen, causes damage by the action of the cholesterol-binding virulence factor pneumolysin and by stimulation of the innate immune system, particularly via Toll-like-receptor 2. Methods SH-SY5Y neuroblastoma cells transfected with the G93A mutant of SOD1 typical for familial ALS (G93A-SOD1) and SH-SY5Y neuroblastoma cells transfected with wildtype SOD1 were both exposed to pneumolysin and in co-cultures with cultured human macrophages treated with the Toll like receptor 2 agonist N-palmitoyl-S-[2,3-bis(palmitoyloxy)-(2RS)-propyl]-[R]-cysteinyl-[S]-seryl-[S]-lysyl-[S]-lysyl-[S]-lysyl-[S]-lysyl-[S]-lysine × 3 HCl (Pam3CSK4). Cell viability and apoptotic cell death were compared morphologically and by in-situ tailing. With the help of the WST-1 test, cell viability was quantified, and by measurement of neuron-specific enolase in the culture supernatant neuronal damage in co-cultures was investigated. Intracellular calcium levels were measured by fluorescence analysis using fura-2 AM. Results SH-SY5Y neuroblastoma cells transfected with the G93A mutant of SOD1 typical for familial ALS (G93A-SOD1) were more vulnerable to the neurotoxic action of pneumolysin and to the attack of monocytes stimulated by Pam3CSK4 than SH-SY5Y cells transfected with wild-type human SOD1. The enhanced pneumolysin toxicity in G93A-SOD1 neuronal cells depended on the inability of these cells to cope with an increased calcium influx caused by pores formed by pneumolysin. This inability was caused by an impaired capacity of the mitochondria to remove cytoplasmic calcium. Treatment of G93A-SOD1 SH-SY5Y neuroblastoma cells with the antioxidant N-acetylcysteine reduced the toxicity of pneumolysin. Conclusion The particular vulnerability of G93A-SOD1 neuronal cells to hemolysins and inflammation may be partly responsible for the clinical deterioration of ALS patients during infections. These findings link infection and motor neuron disease and suggest early treatment of respiratory infections in ALS patients.
Collapse
Affiliation(s)
- Miriam Goos
- Department of Neurology, Georg-August-University of Göttingen, Göttingen, Germany.
| | | | | | | | | | | | | | | | | |
Collapse
|
12
|
Grandgirard D, Schürch C, Cottagnoud P, Leib SL. Prevention of brain injury by the nonbacteriolytic antibiotic daptomycin in experimental pneumococcal meningitis. Antimicrob Agents Chemother 2007; 51:2173-8. [PMID: 17371820 PMCID: PMC1891377 DOI: 10.1128/aac.01014-06] [Citation(s) in RCA: 93] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Bacteriolytic antibiotics cause the release of bacterial components that augment the host inflammatory response, which in turn contributes to the pathophysiology of brain injury in bacterial meningitis. In the present study, antibiotic therapy with nonbacteriolytic daptomycin was compared with that of bacteriolytic ceftriaxone in experimental pneumococcal meningitis, and the treatments were evaluated for their effects on inflammation and brain injury. Eleven-day-old rats were injected intracisternally with 1.3 x 10(4) +/- 0.5 x 10(4) CFU of Streptococcus pneumoniae serotype 3 and randomized to therapy with ceftriaxone (100 mg/kg of body weight subcutaneously [s.c.]; n = 55) or daptomycin (50 mg/kg s.c.; n = 56) starting at 18 h after infection. The cerebrospinal fluid (CSF) was assessed for bacterial counts, matrix metalloproteinase-9 levels, and tumor necrosis factor alpha levels at different time intervals after infection. Cortical brain damage was evaluated at 40 h after infection. Daptomycin cleared the bacteria more efficiently from the CSF than ceftriaxone within 2 h after the initiation of therapy (log(10) 3.6 +/- 1.0 and log(10) 6.3 +/- 1.4 CFU/ml, respectively; P < 0.02); reduced the inflammatory host reaction, as assessed by the matrix metalloproteinase-9 concentration in CSF 40 h after infection (P < 0.005); and prevented the development of cortical injury (cortical injury present in 0/30 and 7/28 animals, respectively; P < 0.004). Compared to ceftriaxone, daptomycin cleared the bacteria from the CSF more rapidly and caused less CSF inflammation. This combined effect provides an explanation for the observation that daptomycin prevented the development of cortical brain injury in experimental pneumococcal meningitis. Further research is needed to investigate whether nonbacteriolytic antibiotic therapy with daptomycin represents an advantageous alternative over current bacteriolytic antibiotic therapies for the treatment of pneumococcal meningitis.
Collapse
Affiliation(s)
- Denis Grandgirard
- Institute for Infectious Diseases, University of Bern, Friedbuehlstrasse 51, CH-3010 Bern, Switzerland
| | | | | | | |
Collapse
|
13
|
Herrmann I, Kellert M, Schmidt H, Mildner A, Hanisch UK, Brück W, Prinz M, Nau R. Streptococcus pneumoniae Infection aggravates experimental autoimmune encephalomyelitis via Toll-like receptor 2. Infect Immun 2006; 74:4841-8. [PMID: 16861672 PMCID: PMC1539614 DOI: 10.1128/iai.00026-06] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The course of autoimmune inflammatory diseases of the central nervous system (CNS) can be influenced by infections. Here we assessed the disease-modulating effects of the most frequent respiratory pathogen Streptococcus pneumonia on the course of experimental autoimmune encephalomyelitis (EAE). Mice were immunized with myelin oligodendrocyte glycoprotein 35-55 (MOG(35-55)) peptide, challenged intraperitoneally with live S. pneumoniae type 3, and then treated with ceftriaxone. EAE was monitored by a clinical score for 35 days after immunization. EAE was unaltered in mice infected with S. pneumoniae 2 days before and 21 days after the first MOG(35-55) injection but was more severe in animals infected 7 days after the first MOG(35-55) injection. The antigen-driven systemic T-cell response was unaltered, and the intraspinal Th1 cytokine mRNA concentrations at the peak of disease were unchanged. The composition of CNS-infiltrating cells and subsequent tissue destruction were only slightly increased after S. pneumoniae infection. In contrast, the serum levels of tumor necrosis factor alpha and interleukin-6 and spinal interleukin-6 levels were elevated, and the expression of major histocompatibility complex class II molecules, CD80, and CD86 on splenic dendritic cells were enhanced early after infection. Serum cytokine concentrations were not elevated, and EAE was not aggravated by S. pneumoniae infection in Toll-like receptor 2 (TLR2)-deficient mice. In conclusion, infection with S. pneumoniae worsens EAE probably by elevation of proinflammatory cytokines and activation of dendritic cells in the systemic circulation via TLR2 and cross talk through the blood-brain barrier.
Collapse
Affiliation(s)
- Isabel Herrmann
- Department of Neurology, Georg August University, Robert-Koch-Str. 40, D-37075 Göttingen, Germany
| | | | | | | | | | | | | | | |
Collapse
|
14
|
English BK, Maryniw EM, Talati AJ, Meals EA. Diminished macrophage inflammatory response to Staphylococcus aureus isolates exposed to daptomycin versus vancomycin or oxacillin. Antimicrob Agents Chemother 2006; 50:2225-7. [PMID: 16723590 PMCID: PMC1479096 DOI: 10.1128/aac.01559-05] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Exposure of any of six clinical isolates of Staphylococcus aureus to daptomycin alone or in combination with vancomycin or oxacillin (compared with vancomycin or oxacillin alone) led to a dampened macrophage inflammatory response with diminished tumor necrosis factor secretion and reduced accumulation of inducible nitric oxide synthase protein.
Collapse
Affiliation(s)
- B Keith English
- Department of Pediatrics, University of Tennessee Health Science Center, 38103, USA.
| | | | | | | |
Collapse
|
15
|
Abstract
PURPOSE OF REVIEW The mortality of bacterial meningitis can reach 30%, and up to 50% of survivors suffer from persisting neurological deficits as a consequence of the disease. The incidence of neurological sequelae of bacterial meningitis has not improved over the last decade. Adjunctive therapeutic options are limited, and ongoing research into the pathophysiology of brain damage in bacterial meningitis aims at providing the scientific basis for future development of more efficient adjunctive options. RECENT FINDINGS In a population with good access to health care, dexamethasone given before or at the time of initiation of antibiotic therapy acts beneficially in paediatric pneumococcal meningitis, but not in meningococcal meningitis. In experimental animal models, brain-derived neurotrophic factor protected against brain injury and improved hearing while melatonin, which has antioxidant properties among other effects, reduced neuronal death. Transgene technology can be used to provide new insights into the pathophysiology of the disease and to identify potential therapeutic targets. SUMMARY Although dexamethasone improves outcome of bacterial meningitis under defined circumstances, the morbidity of bacterial meningitis still remains unacceptably high. Experimental models may help to identify new therapeutic strategies to further improve the neurological outcome in young children suffering from bacterial meningitis.
Collapse
|