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Flórez P, de Castro M, Rodríguez D, Gonzalo-Orden JM, Carvajal A. Intralaboratory Validation of a Kinetic Turbidimetric Assay Based on Limulus Amebocyte Lysate (LAL) for Assessing Endotoxin Activity in Cow Milk. Animals (Basel) 2023; 13:ani13030427. [PMID: 36766315 PMCID: PMC9913736 DOI: 10.3390/ani13030427] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2022] [Revised: 01/23/2023] [Accepted: 01/24/2023] [Indexed: 01/28/2023] Open
Abstract
Mastitis, one of the most common diseases in dairy cattle, causes severe losses in the dairy sector worldwide and affects animal welfare. The disease is characterized by an inflammatory reaction of the mammary gland and is mainly caused by bacterial infections, including both Gram-negative and Gram-positive bacteria. The release of endotoxins associated to bacterial lysis is a weighty factor in the clinical course of Gram-negative associated mastitis and should be taken into consideration when using antibiotics in the treatment of these infections. Therefore, endotoxin detection in milk samples would be of help in the management of bovine mastitis. With this aim, we have validated a kinetic turbidimetric assay based on Limulus amebocyte lysate (LAL) for the quantification of endotoxins in milk samples. The assay was adapted to this particular matrix by incorporating filtration and dilution of the milk samples in the procedure. Our results demonstrate the robustness and usefulness of the assay, which allows the identification of coliform mastitis in milk samples from affected cows and the quantification of endotoxin activity in bulk and commercial milk samples. Further studies are required to evaluate the performance of the assay in mastitis milk samples associated to Gram-negative bacteria other than Escherichia coli as well as during the clinical course of these Gram-negative mastitis or after their treatment with antibiotics.
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Affiliation(s)
- Pablo Flórez
- Laboratorios Analíticos AGROVET, N-601 km312, 24217 Mansilla Mayor, León, Spain
| | - María de Castro
- Laboratorios Analíticos AGROVET, N-601 km312, 24217 Mansilla Mayor, León, Spain
| | - David Rodríguez
- Laboratorios Analíticos AGROVET, N-601 km312, 24217 Mansilla Mayor, León, Spain
| | - José Manuel Gonzalo-Orden
- Departamento de Medicina y Cirugía Animal, Universidad de León, 24071 León, Spain
- Instituto de Biomedicina, IBIOMED, Universidad de León, 24071 León, Spain
| | - Ana Carvajal
- Departamento de Sanidad Animal, Universidad de León, 24071 León, Spain
- Instituto de Desarrollo Ganadero, INDEGSAL, Universidad de León, 24071 León, Spain
- Correspondence:
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2
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Cylke KC, Si F, Banerjee S. Effects of antibiotics on bacterial cell morphology and their physiological origins. Biochem Soc Trans 2022; 50:1269-1279. [PMID: 36093840 PMCID: PMC10152891 DOI: 10.1042/bst20210894] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2022] [Revised: 08/05/2022] [Accepted: 08/17/2022] [Indexed: 11/17/2022]
Abstract
Characterizing the physiological response of bacterial cells to antibiotic treatment is crucial for the design of antibacterial therapies and for understanding the mechanisms of antibiotic resistance. While the effects of antibiotics are commonly characterized by their minimum inhibitory concentrations or the minimum bactericidal concentrations, the effects of antibiotics on cell morphology and physiology are less well characterized. Recent technological advances in single-cell studies of bacterial physiology have revealed how different antibiotic drugs affect the physiological state of the cell, including growth rate, cell size and shape, and macromolecular composition. Here, we review recent quantitative studies on bacterial physiology that characterize the effects of antibiotics on bacterial cell morphology and physiological parameters. In particular, we present quantitative data on how different antibiotic targets modulate cellular shape metrics including surface area, volume, surface-to-volume ratio, and the aspect ratio. Using recently developed quantitative models, we relate cell shape changes to alterations in the physiological state of the cell, characterized by changes in the rates of cell growth, protein synthesis and proteome composition. Our analysis suggests that antibiotics induce distinct morphological changes depending on their cellular targets, which may have important implications for the regulation of cellular fitness under stress.
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Affiliation(s)
- K. Callaghan Cylke
- Department of Physics, Carnegie Mellon University, Pittsburgh, PA 15213, USA
| | - Fangwei Si
- Department of Physics, Carnegie Mellon University, Pittsburgh, PA 15213, USA
- The Scripps Research Institute, La Jolla, CA 92037, USA
| | - Shiladitya Banerjee
- Department of Physics, Carnegie Mellon University, Pittsburgh, PA 15213, USA
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3
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Lazenby JJ, Li ES, Whitchurch CB. Cell wall deficiency - an alternate bacterial lifestyle? MICROBIOLOGY (READING, ENGLAND) 2022; 168. [PMID: 35925044 DOI: 10.1099/mic.0.001218] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Historically, many species of bacteria have been reported to produce viable, cell wall deficient (CWD) variants. A variety of terms have been used to refer to CWD bacteria and a plethora of methods described in which to induce, cultivate and propagate them. In this review, we will examine the long history of scientific research on CWD bacteria examining the methods by which CWD bacteria are generated; the requirements for survival in a CWD state; the replicative processes within a CWD state; and the reversion of CWD bacteria into a walled state, or lack thereof. In doing so, we will present evidence that not all CWD variants are alike and that, at least in some cases, CWD variants arise through an adaptive lifestyle switch that enables them to live and thrive without a cell wall, often to avoid antimicrobial activity. Finally, the implications of CWD bacteria in recurring infections, tolerance to antibiotic therapy and antimicrobial resistance will be examined to illustrate the importance of greater understanding of the CWD bacteria in human health and disease.
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Affiliation(s)
- James J Lazenby
- Quadram Institute Bioscience, Norwich Research Park, Norwich NR4 7UQ, UK
| | - Erica S Li
- Quadram Institute Bioscience, Norwich Research Park, Norwich NR4 7UQ, UK
| | - Cynthia B Whitchurch
- Quadram Institute Bioscience, Norwich Research Park, Norwich NR4 7UQ, UK
- School of Biological Sciences, University of East Anglia, Norwich NR4 7TK, UK
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Clinical Biofilm Ring Test ® Reveals the Potential Role of β-Lactams in the Induction of Biofilm Formation by P. aeruginosa in Cystic Fibrosis Patients. Pathogens 2020; 9:pathogens9121065. [PMID: 33352641 PMCID: PMC7766936 DOI: 10.3390/pathogens9121065] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2020] [Revised: 12/15/2020] [Accepted: 12/16/2020] [Indexed: 12/03/2022] Open
Abstract
Biofilms are characterized by high tolerance to antimicrobials. However, conventional antibiograms are performed on planktonic microorganisms. Through the clinical Biofilm Ring Test® (cBRT), initially aimed to measure the adhesion propensity of bacteria, we discerned a variable distribution of biofilm-producer strains among P. aeruginosa samples isolated from expectorations of cystic fibrosis (CF) patients. Despite a majority of spontaneous adherent isolates, few strains remained planktonic after 5 h of incubation. Their analysis by an adapted protocol of the cBRT revealed an induction of the biofilm early formation by sub-inhibitory doses of β-lactams. Microscopic observations of bacterial cultures stained with Syto 9/Propidium Iodide (PI) confirmed the ability of antimicrobials to increase either the bacterial biomass or the biovolume occupied by induced sessile cells. Finally, the cBRT and its derivatives enabled to highlight in a few hours the potential inducer property of antibiotics on bacterial adhesion. This phenomenon should be considered carefully in the context of CF since patients are constantly under fluctuating antimicrobial treatments. To conclude, assays derived from the Biofilm Ring Test® (BRT) device, not only define efficient doses preventing biofilm formation, but could be useful for the antimicrobial selection in CF, to avoid inducer molecules of the early biofilm initiation.
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Extension of Pharmacokinetic/Pharmacodynamic Time-Kill Studies To Include Lipopolysaccharide/Endotoxin Release from Escherichia coli Exposed to Cefuroxime. Antimicrob Agents Chemother 2020; 64:AAC.02070-19. [PMID: 31988100 PMCID: PMC7179275 DOI: 10.1128/aac.02070-19] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2019] [Accepted: 01/14/2020] [Indexed: 12/17/2022] Open
Abstract
The release of inflammatory bacterial products, such as lipopolysaccharide (LPS)/endotoxin, may be increased upon the administration of antibiotics. An improved quantitative understanding of endotoxin release and its relation to antibiotic exposure and bacterial growth/killing may be gained by an integrated analysis of these processes. The aim of this work was to establish a mathematical model that relates Escherichia coli growth/killing dynamics at various cefuroxime concentrations to endotoxin release in vitro. The release of inflammatory bacterial products, such as lipopolysaccharide (LPS)/endotoxin, may be increased upon the administration of antibiotics. An improved quantitative understanding of endotoxin release and its relation to antibiotic exposure and bacterial growth/killing may be gained by an integrated analysis of these processes. The aim of this work was to establish a mathematical model that relates Escherichia coli growth/killing dynamics at various cefuroxime concentrations to endotoxin release in vitro. Fifty-two time-kill experiments informed bacterial and endotoxin time courses and included both static (0×, 0.5×, 1×, 2×, 10×, and 50× MIC) and dynamic (0×, 15×, and 30× MIC) cefuroxime concentrations. A model for the antibiotic-bacterium interaction was established, and antibiotic-induced bacterial killing followed a sigmoidal Emax relation to the cefuroxime concentration (MIC-specific 50% effective concentration [EC50], maximum antibiotic-induced killing rate [Emax] = 3.26 h−1 and γ = 3.37). Endotoxin release was assessed in relation to the bacterial processes of growth, antibiotic-induced bacterial killing, and natural bacterial death and found to be quantitatively related to bacterial growth (0.000292 endotoxin units [EU]/CFU) and antibiotic-induced bacterial killing (0.00636 EU/CFU). Increased release following the administration of a second cefuroxime dose was described by the formation and subsequent antibiotic-induced killing of filaments (0.295 EU/CFU). Release due to growth was instantaneous, while release due to antibiotic-induced killing was delayed (mean transit time of 7.63 h). To conclude, the in vitro release of endotoxin is related to bacterial growth and antibiotic-induced killing, with higher rates of release upon the killing of formed filaments. Endotoxin release over 24 h is lowest when antibiotic exposure rapidly eradicates bacteria, while increased release is predicted to occur when growth and antibiotic-induced killing occur simultaneously.
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Spalding C, Keen E, Smith DJ, Krachler AM, Jabbari S. Mathematical modelling of the antibiotic-induced morphological transition of Pseudomonas aeruginosa. PLoS Comput Biol 2018; 14:e1006012. [PMID: 29481562 PMCID: PMC5843380 DOI: 10.1371/journal.pcbi.1006012] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2017] [Revised: 03/08/2018] [Accepted: 01/31/2018] [Indexed: 11/18/2022] Open
Abstract
Here we formulate a mechanistic mathematical model to describe the growth dynamics of P. aeruginosa in the presence of the β-lactam antibiotic meropenem. The model is mechanistic in the sense that carrying capacity is taken into account through the dynamics of nutrient availability rather than via logistic growth. In accordance with our experimental results we incorporate a sub-population of cells, differing in morphology from the normal bacillary shape of P. aeruginosa bacteria, which we assume have immunity from direct antibiotic action. By fitting this model to experimental data we obtain parameter values that give insight into the growth of a bacterial population that includes different cell morphologies. The analysis of two parameters sets, that produce different long term behaviour, allows us to manipulate the system theoretically in order to explore the advantages of a shape transition that may potentially be a mechanism that allows P. aeruginosa to withstand antibiotic effects. Our results suggest that inhibition of this shape transition may be detrimental to bacterial growth and thus suggest that the transition may be a defensive mechanism implemented by bacterial machinery. In addition to this we provide strong theoretical evidence for the potential therapeutic strategy of using antimicrobial peptides (AMPs) in combination with meropenem. This proposed combination therapy exploits the shape transition as AMPs induce cell lysis by forming pores in the cytoplasmic membrane, which becomes exposed in the spherical cells. Antimicrobial resistance is an urgent global health threat and it is critical that we formulate alternative treatment strategies to combat bacterial infections. To do this we must understand how bacteria respond to currently used antibiotics. Pseudomonas aeruginosa is the leading cause of death among cystic fibrosis patients, a top cause of hospital-acquired infections in the UK and is currently listed as a critical priority in a list of antibiotic-resistant bacteria produced by the World Health Organisation. P. aeruginosa can change shape in the presence of certain antibiotics that work by targeting cell wall synthesis. The bacteria make the reversible transition from the native rod shape to a fragile spherical shape by shedding the cell wall and in doing so they evade the effects of the antibiotic. We formulate a system of equations that describes the growth of the bacteria including the shape transition we witness when we add antibiotic. Fitting this model to experimental data, we obtain parameter values that we then vary to make predictions on how inhibiting the shape transition or increasing the death rate of spherical cells would affect the overall bacterial growth. These predictions can support suitable combination therapies and hint towards alternative treatment strategies.
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Affiliation(s)
- Chloe Spalding
- School of Mathematics, University of Birmingham, Edgbaston Campus, Birmingham, United Kingdom
- Institute of Microbiology and Infection, School of Biosciences, University of Birmingham, Edgbaston Campus, Birmingham, United Kingdom
- * E-mail: (CS); (SJ)
| | - Emma Keen
- Institute of Microbiology and Infection, School of Biosciences, University of Birmingham, Edgbaston Campus, Birmingham, United Kingdom
| | - David J. Smith
- School of Mathematics, University of Birmingham, Edgbaston Campus, Birmingham, United Kingdom
- Institute for Metabolism and Systems Research, University of Birmingham, Edgbaston Campus, Birmingham, United Kingdom
| | - Anne-Marie Krachler
- Department of Microbiology and Molecular Genetics, University of Texas McGovern Medical School at Houston, Houston, Texas, United States of America
| | - Sara Jabbari
- School of Mathematics, University of Birmingham, Edgbaston Campus, Birmingham, United Kingdom
- Institute of Microbiology and Infection, School of Biosciences, University of Birmingham, Edgbaston Campus, Birmingham, United Kingdom
- * E-mail: (CS); (SJ)
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7
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Cushnie TPT, O'Driscoll NH, Lamb AJ. Morphological and ultrastructural changes in bacterial cells as an indicator of antibacterial mechanism of action. Cell Mol Life Sci 2016; 73:4471-4492. [PMID: 27392605 PMCID: PMC11108400 DOI: 10.1007/s00018-016-2302-2] [Citation(s) in RCA: 93] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2016] [Revised: 06/21/2016] [Accepted: 06/28/2016] [Indexed: 01/20/2023]
Abstract
Efforts to reduce the global burden of bacterial disease and contend with escalating bacterial resistance are spurring innovation in antibacterial drug and biocide development and related technologies such as photodynamic therapy and photochemical disinfection. Elucidation of the mechanism of action of these new agents and processes can greatly facilitate their development, but it is a complex endeavour. One strategy that has been popular for many years, and which is garnering increasing interest due to recent technological advances in microscopy and a deeper understanding of the molecular events involved, is the examination of treated bacteria for changes to their morphology and ultrastructure. In this review, we take a critical look at this approach. Variables affecting antibacterial-induced alterations are discussed first. These include characteristics of the test organism (e.g. cell wall structure) and incubation conditions (e.g. growth medium osmolarity). The main body of the review then describes the different alterations that can occur. Micrographs depicting these alterations are presented, together with information on agents that induce the change, and the sequence of molecular events that lead to the change. We close by highlighting those morphological and ultrastructural changes which are consistently induced by agents sharing the same mechanism (e.g. spheroplast formation by peptidoglycan synthesis inhibitors) and explaining how changes that are induced by multiple antibacterial classes (e.g. filamentation by DNA synthesis inhibitors, FtsZ disruptors, and other types of agent) can still yield useful mechanistic information. Lastly, recommendations are made regarding future study design and execution.
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Affiliation(s)
- T P Tim Cushnie
- Faculty of Medicine, Mahasarakham University, Khamriang, Kantarawichai, Maha Sarakham, 44150, Thailand.
| | - Noëlle H O'Driscoll
- School of Pharmacy and Life Sciences, Robert Gordon University, Sir Ian Wood Building, Garthdee Road, Aberdeen, AB10 7GJ, UK
| | - Andrew J Lamb
- School of Pharmacy and Life Sciences, Robert Gordon University, Sir Ian Wood Building, Garthdee Road, Aberdeen, AB10 7GJ, UK
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8
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Kell DB, Pretorius E. On the translocation of bacteria and their lipopolysaccharides between blood and peripheral locations in chronic, inflammatory diseases: the central roles of LPS and LPS-induced cell death. Integr Biol (Camb) 2016; 7:1339-77. [PMID: 26345428 DOI: 10.1039/c5ib00158g] [Citation(s) in RCA: 111] [Impact Index Per Article: 13.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
We have recently highlighted (and added to) the considerable evidence that blood can contain dormant bacteria. By definition, such bacteria may be resuscitated (and thus proliferate). This may occur under conditions that lead to or exacerbate chronic, inflammatory diseases that are normally considered to lack a microbial component. Bacterial cell wall components, such as the endotoxin lipopolysaccharide (LPS) of Gram-negative strains, are well known as potent inflammatory agents, but should normally be cleared. Thus, their continuing production and replenishment from dormant bacterial reservoirs provides an easy explanation for the continuing, low-grade inflammation (and inflammatory cytokine production) that is characteristic of many such diseases. Although experimental conditions and determinants have varied considerably between investigators, we summarise the evidence that in a great many circumstances LPS can play a central role in all of these processes, including in particular cell death processes that permit translocation between the gut, blood and other tissues. Such localised cell death processes might also contribute strongly to the specific diseases of interest. The bacterial requirement for free iron explains the strong co-existence in these diseases of iron dysregulation, LPS production, and inflammation. Overall this analysis provides an integrative picture, with significant predictive power, that is able to link these processes via the centrality of a dormant blood microbiome that can resuscitate and shed cell wall components.
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Affiliation(s)
- Douglas B Kell
- School of Chemistry and The Manchester Institute of Biotechnology, The University of Manchester, 131, Princess St, Manchester M1 7DN, Lancs, UK.
| | - Etheresia Pretorius
- Department of Physiology, Faculty of Health Sciences, University of Pretoria, Arcadia 0007, South Africa.
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9
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Healy D, Clendening C, Neely A, Holder I. Antibiotic-induced endotoxin release is organism-dependent in experimental Gram-negative sepsis. ACTA ACUST UNITED AC 2016. [DOI: 10.1177/096805199700400502] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
The majority of in vitro and animal experiments that have been performed to assess antibiotic-induced endotoxin release (AIER) have employed a single test isolate, usually Escherichia coli. To determine the influence of microorganism type on AIER and interleukin-6 (IL-6) response, CF-1 mice were made septic following a 12-15% total body surface area nonlethal burn and subeschar challenge (LD90) with Klebsiella pneumoniae K2 (∼103 cfu), Proteus mirabilis 4552 (∼101 cfu) and Pseudomonas aeruginosa SBI-N (∼102 cfu). Three intraperitoneal (i.p.) doses, given every 4 h, of ceftazidime (TAZ, 200 mg/kg), imipenem (IMI, 100 mg/kg), ciprofloxacin (CIP, 25 mg/kg) and gentamicin (GEN, 25 mg/kg) were administered post burn and infection beginning when mice were septic with organ dysfunction. Free endotoxin concentrations were significantly ( P < 0.001) higher following all antibiotics for treatment of K. pneumoniae as compared to Ps. aeruginosa (intermediate) and P. mirabilis infections. Differential AIER was highest for TAZ and IMI, intermediate for CIP and lowest for GEN, for the treatment of K. pneumoniae and Ps. aeruginosa infections. There was a strong positive correlation between endotoxin release and IL-6 production for K. pneumoniae-treated animals, however increased endotoxin levels for Pseudomonas were accompanied by decreases in IL-6 levels. For P. mirabilis infection endotoxin levels were comparatively low, but highest for GEN and IMI. However, corresponding IL-6 levels increased only 3.2-fold for IMI and actually decreased by 50% for GEN following the first dose. Interestingly, CIP resulted in only modest endotoxin release and TAZ caused no appreciable release, however IL-6 concentrations dramatically increased 39.9-fold (TAZ) and 32.6-fold (CIP). This suggests that other pro-inflammatory mediators released from the bacterium, and not endotoxin, were more important determinants in the overall host response to antibiotic exposure. In conclusion, these data provide supportive evidence that absolute and differential AIER and production of IL-6 is organism-dependent in experimental Gram-negative sepsis. As a result, general conclusions concerning differential AIER for infection caused by E. coli or K. pneumoniae cannot necessarily be extrapolated to other species of Gram-negative bacilli. Furthermore, these study results strongly indicate that the microorganism and other pertinent pro-inflammatory factors (i.e. exotoxins, proteases), must be taken into account in the study design and data analysis of any experimental or clinical trial that is conducted to determine the significance of differential AIER.
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Affiliation(s)
- D.P. Healy
- Shriners Burns Institute, University of Cincinnati Medical Center, Cincinnati, Ohio, USA
| | - C.E. Clendening
- Shriners Burns Institute, University of Cincinnati Medical Center, Cincinnati, Ohio, USA
| | - A.N. Neely
- Shriners Burns Institute, University of Cincinnati Medical Center, Cincinnati, Ohio, USA
| | - I.A. Holder
- Shriners Burns Institute, University of Cincinnati Medical Center, Cincinnati, Ohio, USA
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10
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Peach KC, Bray WM, Winslow D, Linington PF, Linington RG. Mechanism of action-based classification of antibiotics using high-content bacterial image analysis. MOLECULAR BIOSYSTEMS 2013; 9:1837-48. [PMID: 23609915 PMCID: PMC3674180 DOI: 10.1039/c3mb70027e] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Image-based screening has become a mature field over the past decade, largely due to the detailed information that can be obtained about compound mode of action by considering the phenotypic effects of test compounds on cellular morphology. However, very few examples exist of extensions of this approach to bacterial targets. We now report the first high-throughput, high-content platform for the prediction of antibiotic modes of action using image-based screening. This approach employs a unique feature segmentation and extraction protocol to quantify key size and shape metrics of bacterial cells over a range of compound concentrations, and matches the trajectories of these metrics to those of training set compounds of known molecular target to predict the test compound's mode of action. This approach has been used to successfully predict the modes of action of a panel of known antibiotics, and has been extended to the evaluation of natural products libraries for the de novo prediction of compound function directly from primary screening data.
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Affiliation(s)
- Kelly C Peach
- Department of Chemistry and Biochemistry, University of California Santa Cruz, 1156 High Street, Santa Cruz, CA 95064, USA
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11
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Comparative effects of carbapenems on bacterial load and host immune response in a Klebsiella pneumoniae murine pneumonia model. Antimicrob Agents Chemother 2010; 55:836-44. [PMID: 21135187 DOI: 10.1128/aac.00670-10] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
Doripenem is a carbapenem with potent broad-spectrum activity against Gram-negative pathogens, including antibiotic-resistant Enterobacteriaceae. As the incidence of extended-spectrum β-lactamase (ESBL)-producing Gram-negative bacilli is increasing, it was of interest to examine the in vivo comparative efficacy of doripenem, imipenem, and meropenem against a Klebsiella pneumoniae isolate expressing the TEM-26 ESBL enzyme. In a murine lethal lower respiratory infection model, doripenem reduced the Klebsiella lung burden by 2 log(10) CFU/g lung tissue over the first 48 h of the infection. Treatment of mice with meropenem or imipenem yielded reductions of approximately 1.5 log(10) CFU/g during this time period. Seven days postinfection, Klebsiella titers in the lungs of treated mice decreased an additional 2 log(10) CFU/g relative to those in the lungs of untreated control animals. Lipopolysaccharide (LPS) endotoxin release assays indicated that 6 h postinfection, meropenem- and imipenem-treated animals had 10-fold more endotoxin in lung homogenates and sera than doripenem-treated mice. Following doripenem treatment, the maximum endotoxin release postinfection (6 h) was 53,000 endotoxin units (EU)/ml, which was 2.7- and 6-fold lower than imipenem or meropenem-treated animals, respectively. While the levels of several proinflammatory cytokines increased in both the lungs and sera following intranasal K. pneumoniae inoculation, doripenem treatment, but not meropenem or imipenem treatment, resulted in significantly increased interleukin 6 levels in lung homogenates relative to those in lung homogenates of untreated controls, which may contribute to enhanced neutrophil killing of bacteria in the lung. Histological examination of tissue sections indicated less overall inflammation and tissue damage in doripenem-treated mice, consistent with improved antibacterial efficacy, reduced LPS endotoxin release, and the observed cytokine induction profile.
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12
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Riedele C, Reichl U. Interspecies effects in a ceftazidime-treated mixed culture of Pseudomonas aeruginosa, Burkholderia cepacia and Staphylococcus aureus: analysis at the single-species level. J Antimicrob Chemother 2010; 66:138-45. [PMID: 21062793 DOI: 10.1093/jac/dkq394] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
OBJECTIVES in vitro studies commonly use single bacterial isolates for testing antibiotic susceptibilities. However, interspecies effects that may arise when mixed infections are treated with antibiotics can obviously not be investigated by this approach. In the study presented here, the effect of ceftazidime against a model microbial community consisting of Pseudomonas aeruginosa, Burkholderia cepacia and Staphylococcus aureus was studied in order to reveal effects that only may appear in a ceftazidime-treated mixed culture. METHODS time-kill experiments were conducted with mixed and pure cultures in a defined medium containing 30 mg/L ceftazidime. Interspecies effects were revealed by comparing growth and kill dynamics from time-kill experiments with results from untreated mixed and pure cultures. For species-specific cell enumeration, a quantitative terminal restriction fragment length polymorphism was used. Ceftazidime was measured by HPLC. RESULTS P. aeruginosa showed only a lytic phase in the ceftazidime-treated mixed culture, but not in the untreated mixed culture nor in the ceftazidime-treated pure culture. On the other hand, S. aureus did not lyse in the ceftazidime-treated mixed culture, while it did in the untreated mixed culture. CONCLUSIONS this finding suggests that the efficacy of ceftazidime against P. aeruginosa was increased by an interspecies effect during co-cultivation with B. cepacia and S. aureus. The latter seemed to be negatively affected by interspecies effects in mixed culture without ceftazidime. The same effect was nullified when ceftazidime was applied to the mixed culture. Further studies are required to reveal the underlying mechanisms.
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Affiliation(s)
- Christian Riedele
- Bioprocess Engineering, Max-Planck-Institute for Dynamics of Complex Technical Systems, Magdeburg, Germany.
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13
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Walters SM, Dubey VS, Jeffrey NR, Dixon DR. Antibiotic-induced Porphyromonas gingivalis LPS release and inhibition of LPS-stimulated cytokines by antimicrobial peptides. Peptides 2010; 31:1649-53. [PMID: 20541574 DOI: 10.1016/j.peptides.2010.06.001] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/05/2010] [Revised: 06/01/2010] [Accepted: 06/01/2010] [Indexed: 11/25/2022]
Abstract
Bacterial lipopolysaccharide (LPS) release during periodontal infection is a significant component of periodontal disease. We hypothesized that some bacterial LPS release results from bacterial exposure to antibiotics. Therefore, we examined the ability of various classes of antibiotics to induce LPS release from Porphyromonas gingivalis as well as the ability of antimicrobial peptides (AMPs) to inhibit purified LPS. All antibiotics tested against P. gingivalis were able to liberate 1.9-12.9 times more LPS as compared to untreated bacteria. Among the three AMPs tested, LL-37 was found to be the most potent inhibitor of cytokine (tumor necrosis factor-alpha, interleukin-1beta, interleukin-6) production and completely neutralized purified P. ginigivalis LPS activity in the chromogenic limulus amebocyte lysate (LAL) and whole blood cytokine stimulation assays. These observations suggest that therapeutic approaches utilizing AMPs as adjuncts to neutralize released LPS should be considered.
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Affiliation(s)
- S M Walters
- Immunology and Microbiology Branch, US Army Dental and Trauma Research Detachment, Walter Reed Army Institute of Research, Great Lakes Naval Training Center, Great Lakes, IL 60088, USA
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14
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Buijs J, Dofferhoff ASM, Mouton JW, Wagenvoort JHT, van der Meer JWM. Concentration-dependency of beta-lactam-induced filament formation in Gram-negative bacteria. Clin Microbiol Infect 2008; 14:344-9. [PMID: 18261128 DOI: 10.1111/j.1469-0691.2007.01940.x] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Ceftazidime and cefotaxime are beta-lactam antibiotics with dose-related affinities for penicillin-binding protein (PBP)-3 and PBP-1. At low concentrations, these antibiotics inhibit PBP-3, leading to filament formation. Filaments are long strands of non-dividing bacteria that contain enhanced quantities of endotoxin molecules. Higher concentrations of ceftazidime or cefotaxime cause inhibition of PBP-1, resulting in rapid bacterial lysis, which is associated with low endotoxin release. In the present study, 37 isolates of Escherichia coli, Klebsiella spp., Pseudomonas aeruginosa and Acinetobacter spp. were studied over a 4-h incubation period in the presence of eight concentrations of ceftazidime or cefotaxime. As resistance of Gram-negative bacteria is an emerging problem in clinical practice, 14 isolates of E. coli and Klebsiella pneumoniae that produced extended-spectrum beta-lactamases (ESBLs) were also investigated. Morphological changes after exposure to the beta-lactam antibiotics revealed recognisable patterns in various bacterial families, genera and isolates. In general, all isolates of Enterobacteriaceae produced filaments within a relatively small concentration range, with similar patterns for E. coli and K. pneumoniae. Pseudomonas and Acinetobacter spp. produced filaments in the presence of clinically-relevant concentrations of both antibiotics as high as 50 mg/L. In all genera, filament-producing capacity was clearly related to the MIC. Ceftazidime induced filament production in more isolates and over wider concentration ranges than did cefotaxime. Interestingly, ESBL-producing isolates were not protected against filament induction. The induction of filament production may lead to additional risks during empirical treatment of severe infections.
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Affiliation(s)
- J Buijs
- Department of Medical Microbiology and Infectious Diseases, Atrium Medical Centre, Heerlen, The Netherlands.
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Goscinski G, Tano E, Löwdin E, Sjölin J. Propensity to release endotoxin after two repeated doses of cefuroxime in an in vitro kinetic model: higher release after the second dose. J Antimicrob Chemother 2007; 60:328-33. [PMID: 17567631 DOI: 10.1093/jac/dkm190] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
OBJECTIVES To study endotoxin release from two strains of Escherichia coli after exposure to two repeated doses of cefuroxime in an in vitro kinetic model. METHODS Cefuroxime in concentrations simulating human pharmacokinetics was added to the bacterial solution with a repeated dose after 12 h. In another experiment, tobramycin was given concomitantly with the second dose of cefuroxime. Samples for viable counts and endotoxin analyses were drawn before the addition of antibiotics and at 2 and 4 h after each dose. RESULTS The propensity to release endotoxin, expressed as log10 endotoxin release (EU)/log10 killed bacteria, was higher after the second than after the first dose, 0.80+/-0.04 and 0.65+/-0.01, respectively, in the ATCC strain and 0.80+/-0.04 and 0.65+/-0.02, respectively, in the clinical strain (P<0.001). Endotoxin was released earlier after the second dose (P<0.001). Addition of tobramycin at the second dose reduced the endotoxin release in comparison with that of cefuroxime alone (P<0.001). CONCLUSIONS The propensity to liberate endotoxin is higher after the second dose of cefuroxime than after the first, resulting in a higher release of endotoxin than expected from bacterial count. The release after the second dose can be reduced by the addition of tobramycin.
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Affiliation(s)
- G Goscinski
- Section of Infectious Diseases, Department of Medical Sciences, Uppsala University, Uppsala, Sweden.
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Buijs J, Dofferhoff ASM, Mouton JW, van der Meer JWM. Continuous administration of PBP-2- and PBP-3-specific β-lactams causes higher cytokine responses in murine Pseudomonas aeruginosa and Escherichia coli sepsis. J Antimicrob Chemother 2007; 59:926-33. [PMID: 17395686 DOI: 10.1093/jac/dkm073] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
OBJECTIVES Initial antibiotic treatment of severe infections can lead to clinical deterioration due to sudden endotoxin release and concomitant exaggerated inflammatory response. Antibiotic-induced morphological changes may contribute to this phenomenon. High-dose ceftazidime, which inhibits penicillin-binding protein (PBP)-1 in Gram-negative bacteria, causes quick bacteriolysis and low endotoxin release. Low-dose ceftazidime leads to PBP-3 inhibition, which causes bacterial filament formation, associated with high endotoxin releases. PBP-2-specific antibiotics induce spheroplasts, again associated with low endotoxin release. We hypothesized that antibiotic type, concentration and regimen influence bacterial morphology, endotoxin levels and inflammatory response. METHODS Neutropenic mice with Escherichia coli or Pseudomonas aeruginosa sepsis were treated with ceftazidime or meropenem 10-320 mg/kg as an intravenous bolus or as continuous tail vein infusions of 0.1 mL/h. Four hours later, bacterial counts, morphology, plasma endotoxin, pro-inflammatory cytokines [tumour necrosis factor-alpha (TNF-alpha) and interleukin-6 (IL-6)] and antibiotic concentrations were measured. RESULTS Continuous infusion of 80 mg/kg ceftazidime was the lowest dose preventing filaments in E. coli infections. Bolus treatment resulted in filament formation, irrespective of the dose. During continuous treatment, IL-6 and TNF-alpha concentrations were higher compared with bolus treatment and controls for both antibiotics and both strains. A clear relationship between cfu counts in muscle and circulating IL-6 was shown (r=- 0.579, P=0.007), suggesting that plasma IL-6 is a valuable indicator of bacterial killing at the infection site. CONCLUSIONS Our findings show that not PBP affinity but the method of antibiotic administration is crucial during initial treatment of severe infections.
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Affiliation(s)
- Jacqueline Buijs
- Department of Medical Microbiology and Infectious Diseases, Canisius-Wilhelmina Hospital, Nijmegen, The Netherlands. /
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Buijs J, Dofferhoff ASM, Mouton JW, van der Meer JWM. Pathophysiology of in-vitro induced filaments, spheroplasts and rod-shaped bacteria in neutropenic mice. Clin Microbiol Infect 2006; 12:1105-11. [PMID: 17002610 DOI: 10.1111/j.1469-0691.2006.01503.x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
This study compared the in-vitro properties and in-vivo effects of Escherichia coli filaments, spheroplasts and normal cells in a murine thigh infection model. E. coli was exposed to ceftazidime, meropenem or saline to obtain filaments, spheroplasts or normal bacilli, which were then injected into neutropenic mice. After 24 h, morphology, CFUs, local and circulating endotoxin levels, cytokine levels and mortality were recorded, and correlations between bacterial and host parameters of infection were investigated. Filaments and spheroplasts contained more endotoxin/CFU than controls. Histological studies showed that morphologically altered bacteria changed into rod-shaped cells in the absence of antibiotics. Bacterial spread to the liver was significantly higher in mice challenged with rod-shaped cells, compared with antibiotic-exposed bacteria (p 0.007). Muscle endotoxin levels correlated significantly with circulating interleukin (IL)-6 and tumour necrosis factor (TNF)-alpha, and both pro-inflammatory cytokines were correlated significantly (p 0.011). Despite a tendency toward higher local and systemic concentrations of endotoxin in the filament group, inflammatory responses and survival did not differ between groups. It was concluded that morphologically altered bacteria contain more endotoxin and can regain a rod shape after withdrawal of antibiotics, while non-antibiotic-exposed bacteria show greater spread to the liver. There was a clear intra-individual relationship between local endotoxin, systemic endotoxin, TNF-alpha and IL-6 production, but these parameters did not differ among groups.
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Affiliation(s)
- J Buijs
- Department of Medical Microbiology and Infectious Diseases, Canisius-Wilhelmina Hospital, Nijmegen, The Netherlands.
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Ermak IM, Barabanova AO, Kukarskikh TA, Solovyova TF, Bogdanovich RN, Polyakova AM, Astrina OP, Maleyev VV. Natural polysaccharide carrageenan inhibits toxic effect of gram-negative bacterial endotoxins. Bull Exp Biol Med 2006; 141:230-2. [PMID: 16984104 DOI: 10.1007/s10517-006-0135-y] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The protective effect of polysaccharide carrageenan on the damaging effect of endotoxins of gram-negative bacteria was studied in vivo and in vitro. Carrageenan increased mouse resistance to the toxic effect of LPS. The degree of protection depended on polysaccharide concentration and administration time and route. Pretreatment of donor platelets with carrageenan reduced their aggregation activity caused by cooperative effect of LPS and ADP.
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Affiliation(s)
- I M Ermak
- Pacific Institute of Bioorganic Chemistry, Far-Eastern Division of Russian Academy of Sciences, Vladivostok.
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Atherton RP, Furr M. Endotoxin release after antimicrobial treatment in sick foals is mediated by antimicrobial class. J Equine Vet Sci 2006. [DOI: 10.1016/j.jevs.2006.06.007] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Kawai S, Nakagawa T, Sakayori S, Kobayashi O, Kamiya S. Effect of ciprofloxacin on levels of lipopolysaccharide and cytokines in experimentally induced gram-negative bacterial pneumonia in mice. J Infect Chemother 2006; 12:119-23. [PMID: 16826343 DOI: 10.1007/s10156-006-0442-2] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2006] [Accepted: 03/24/2006] [Indexed: 10/24/2022]
Abstract
This study was performed to examine the ability of ciprofloxacin (CPFX) to suppress the inflammation associated with lipopolysaccharide (LPS) and an inflammatory cytokine in gram-negative bacterial pneumonia. For this purpose we measured viable cell counts in bronchoalveolar lavage fluid (BALF), LPS concentrations in BALF, and BALF levels of tumor necrosis factor-alpha (TNF-alpha) and interleukin-10 (IL-10) in mice exposed to Klebsiella pneumoniae. We used three groups of mice: controls, treated with physiological saline; mice treated with CPFX; and mice treated with ceftadizime (CAZ). The viable cell count in BALF was low in both the CAZ and CPFX groups. LPS values in BALF were significantly lower in the CPFX group than in the CAZ group at 48 and 72 h after K. pneumoniae exposure (48 h, P < 0.001; 72 h, P < 0.05). The BALF TNF-alpha level was significantly higher in the CAZ group at 24, 48, and 72 h compared to levels in the control and CPFX groups (P < 0.05). In conclusion, these results suggest that CPFX inhibited increases of LPS and TNF-alpha in gram-negative bacterial pneumonia, thereby suppressing the lung inflammation that accompanies pneumonia.
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Affiliation(s)
- Shin Kawai
- The First Department of Internal Medicine, Kyorin University, School of Medicine, 6-20-2 Shinkawa, Mitaka, Tokyo, 181-8611, Japan.
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Abstract
Bacterial resistance to established classes of antibiotics in clinical use is continuing to increase, making the need for new agents that can be used to treat the newly multi-drug resistant organisms steadily more urgent. Cephalosporins have been a successful group of antibiotics since they were first introduced to combat drug-resistant organisms, including staphylococci. The history of cephalosporins has emphasised an improvement of their stability towards beta-lactamases, thus expanding their spectrum of activity against important Gram-negative pathogens. New cephalosporins that have potent activity against multi-resistant Gram-positive bacteria, including methicillin-resistant staphylococci and penicillin-resistant pneumococci have recently entered clinical development. At least two of these, BAL-5788 and S-3578, also have Gram-negative activity, which is comparable to that of the third-and fourth-generation cephalosporins, making them broad-spectrum agents that could be used in hospital infections where methicillin-resistant staphylococci is likely to be present.
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Silverstein R, Johnson DC. Endogenous versus exogenous glucocorticoid responses to experimental bacterial sepsis. J Leukoc Biol 2003; 73:417-27. [PMID: 12660216 DOI: 10.1189/jlb.0702379] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Although lack of adrenals dramatically reduces resistance against sepsis generally, the value of glucocorticoid levels above those normally produced by stress remains controversial. An early and long-held concept is that glucocorticoid protection against lipopolysaccharides in animal models is important. Supporting this concept, C3H/HeJ mice, lacking Toll-like receptor-4 (TLR-4), and consequently, endotoxin hyporesponsive, have recently been shown to be resistant to glucocorticoid protection against live Escherichia coli. Effective antibiotic intervention, as an additional parameter and with concomitant administration of glucocorticoid, not only allows for expected antibiotic protection but also for glucocorticoid protection against E. coli or Staphylococcus aureus of mice sensitized to tumor necrosis factor alpha, regardless of the status of the TLR-4 receptor. TLRs, including but not limited to TLR-2, may be involved in glucocorticoid protective efficacy against Gram-positive and Gram-negative sepsis. Overlapping and possibly endotoxin-independent signaling may become important considerations.
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Affiliation(s)
- Richard Silverstein
- Department of Biochemistry, University of Kansas School of Medicine, Kansas City, USA.
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Abstract
OBJECTIVE To review the preclinical and clinical evidence that antiendotoxin therapeutic strategies are potentially useful in the prevention and treatment of septic shock. STUDY DESIGN A critical review of the literature over the past 30 yrs relating basic and clinical research on the therapeutic value of endotoxin as a target for the prevention and treatment of severe sepsis and septic shock. MAIN RESULTS Bacterial endotoxin is a potent and predominant microbial mediator that induces an intense inflammatory and procoagulant response by elements of the innate immune response. This macromolecule is capable of inducing lethal septic shock in experimental animals, and a large number of preclinical studies consistently demonstrate the survival advantage of endotoxin inhibition in experimental models of sepsis. Clinical studies indicate that endotoxin may be found in the systemic circulation in the majority of humans with septic shock. Endotoxemia is largely independent of the nature of the infecting microorganism despite the fact that this molecule is specifically found in the outer membrane of Gram-negative bacteria only. Antiendotoxin strategies studied thus far have not provided reproducible survival benefits in clinical trials in septic patients. CONCLUSIONS Despite compelling evidence of the critical importance of endotoxin in the pathogenesis of Gram-negative bacterial sepsis in preclinical investigations and numerous clinical interventional trials, the utility of antiendotoxin approaches to significantly reduce the mortality rate in human septic shock remains unproven. Ongoing clinical trials with specific endotoxin inhibitors should determine the potential value of this therapeutic approach to the management of septic shock.
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Affiliation(s)
- Steven M Opal
- Infectious Disease Division, Brown Medical School, Providence, RI, USA
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Healy DP, Silverman PA, Neely AN, Holder IA, Babcock GE. Effect of antibiotics on polymorphonuclear neutrophil apoptosis. Pharmacotherapy 2002; 22:578-85. [PMID: 12013356 DOI: 10.1592/phco.22.8.578.33217] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
STUDY OBJECTIVE To evaluate the effects of various antibiotics-direct and indirect as a result of bacterial killing-on polymorphonuclear neutrophil (PMN) apoptosis. DESIGN In vitro analysis. SETTING Research laboratory. INTERVENTION Whole blood collected from healthy human subjects was incubated with and without Klebsiella pneumoniae (1.0 x 10(5) colony-forming units [cfu]/ml) plus ceftazidime 50 microg/ml, gentamicin, ciprofloxacin, trovafloxacin, tetracycline, doxycycline, erythromycin, azithromycin (each 5 microg/ml), or lipopolysaccharide 10 microg/ml. After staining with fluorescein-conjugated annexin V, red blood cells were lysed, and the remaining white blood cells were assessed by flow cytometry with gating on PMNs. MEASUREMENTS AND MAIN RESULTS In the absence of K. pneumoniae infection, antibiotic exposure directly decreased PMN apoptosis by 17.8% (range -25.0% to -13.9%, p=0.008) compared with untreated cells. In the presence of K. pneumoniae, all antibiotic treatments, even those with poor in vitro activity for the bacterial isolate, decreased PMN apoptosis by 26.2% (range -38.0% to -17.8%, p<0.001) compared with untreated control cells and by 36.6% compared with untreated (no antibiotic) K. pneumoniae-stimulated cells (range -46.2% to -28.0%, p<0.001). CONCLUSIONS All tested antibiotics in clinically relevant concentrations resulted in modest yet consistent decreases in PMN apoptosis. The magnitude of this change increased slightly in the presence of K. pneumoniae infection. In vivo studies are needed to determine whether antibiotic-associated prolongation of PMN survival improves host response to infection.
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Affiliation(s)
- Daniel P Healy
- College of Pharmacy, University of Cincinnati, OH 45267, USA
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Horii T, Kimura T, Nadai M, Kobayashi M. Lincomycin-induced endotoxin release in Escherichia coli sepsis: evidence for release in vitro and in vivo. Int J Infect Dis 2001; 4:118-22. [PMID: 11179913 DOI: 10.1016/s1201-9712(00)90071-7] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/1998] [Accepted: 04/05/1999] [Indexed: 11/23/2022] Open
Abstract
OBJECTIVE To evaluate the propensity of lincomycin and clindamycin to induce release of endotoxin, the authors investigated endotoxin release in Escherichia coli isolated from a patient who developed septic shock following lincomycin treatment. METHODS Endotoxin release from the E. coli isolate exposed to lincomycin, clindamycin, and ceftazidime were determined in vitro and in vivo. RESULTS In vitro, this E. coli released significantly larger amounts of endotoxin after exposure for 6 hours to lincomycin or clindamycin versus no antibiotic; however, endotoxin release with these antibiotics was significantly less than with ceftazidime. There was no significant difference in in vitro endotoxin release between small (8 mg/L) and large (0.5 minimum inhibitory concentration [MIC]) doses of these antibiotics, and 0.5 MICs of lincomycin and clindamycin were 1024 and 256 mg/L, respectively. These results were supported by scanning electron microscopic observations, which demonstrated that lincomycin, clindamycin, and ceftazidime induced formation of filamentous cells. In addition, plasma endotoxin concentrations after treatment for 4 hours with lincomycin, clindamycin, and ceftazidime (5 mg/kg) were at least 20-fold higher than with no antibiotic in an E. coli sepsis rat model. CONCLUSION Results of this study suggest that the bacteriostatic antibiotics, lincomycin and clindamycin, induce endotoxin release in the treatment of E. coli infections.
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Affiliation(s)
- T Horii
- Department of Internal Medicine, Tsushima Chuoh Hospital, Tsushima, Japan.
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Okereke CS. Advances in the use of carbapenem antibiotics in the management of serious bacterial infections in special patient populations. I: Safety and efficacy in children and elderly patients. Curr Ther Res Clin Exp 2000. [DOI: 10.1016/s0011-393x(00)80020-x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022] Open
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Luchi M, Morrison DC. Comparable endotoxic properties of lipopolysaccharides are manifest in diverse clinical isolates of gram-negative bacteria. Infect Immun 2000; 68:1899-904. [PMID: 10722580 PMCID: PMC97364 DOI: 10.1128/iai.68.4.1899-1904.2000] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
In general there is a poor correlation between serum lipopolysaccharide (LPS; the biologically active constituent of endotoxin) levels and mortality in septic patients. The objective of this study was to determine if chemical, structural, or biological differences among LPS from different clinical isolates of gram-negative bacteria might explain this discrepancy. LPS preparations were made using the hot phenol-water extraction method from eight clinical isolates of gram-negative bacteria. As a percentage of the total weight of the LPS, the phosphate content ranged from 3.0 to 13.8% (average, 6.7 +/- 3.6%), and the 2-keto-3-deoxyoctonate content ranged from 1.9 to 27.4% (average, 8.9 +/- 8.5%). These values were not dissimilar to those obtained for a reference endotoxin. In a standard measure of LPS activity, the Limulus amoebocyte lysate assay, there was approximately a twofold difference between the least and most active preparations. The two preparations with the greatest difference in their ability to elicit the secretion of tumor necrosis factor alpha from a mouse peritoneal macrophage cell line were similar in lethality when administered to mice sensitized to the effects of LPS by D(+)-galactosamine. These relatively minor differences in LPS activity seem unlikely to explain the generally observed discrepancy between serum endotoxin levels and mortality in patients with gram-negative sepsis.
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Affiliation(s)
- M Luchi
- Department of Medicine, University of Kansas Medical Center, Kansas City, Kansas 66160, USA
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Trautmann M, Heinemann M, Möricke A, Seidelmann M, Lorenz I, Berger D, Steinbach G, Schneider M. Endotoxin release due to ciprofloxacin measured by three different methods. J Chemother 1999; 11:248-54. [PMID: 10465125 DOI: 10.1179/joc.1999.11.4.248] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022]
Abstract
Antibiotics are known to induce the release of bioactive endotoxin (LPS) from gram-negative bacterial cells. Because varying data have been published on the influence of quinolone antibiotics on LPS liberation, we studied the effect of ciprofloxacin on a culture of Escherichia coli by determining bacterial killing and free LPS concentrations in comparison with imipenem and ceftazidime. LPS levels were measured by three different methods, namely (1) the Limulus amebocyte lysate test, (2) an ELISA method based on capture of LPS by monoclonal antibodies, and (3) indirect determination by measuring the ability of antibiotic-induced LPS to trigger TNFalpha release from a monocytic cell line. With both the Limulus and ELISA tests, a low endotoxin-releasing activity of ciprofloxacin was confirmed. In contrast to previous studies, this LPS also had low bioactivity in terms of TNFalpha induction. Limulus LPS determinations correlated more precisely with LPS bioactivity than did ELISA values, an observation which underlines the crucial role of LPS determination methods in studies of antibiotic-induced LPS release.
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Affiliation(s)
- M Trautmann
- Department of Medical Microbiology and Hygiene, University Hospital Ulm, Germany.
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Periti P, Mazzei T. New criteria for selecting the proper antimicrobial chemotherapy for severe sepsis and septic shock. Int J Antimicrob Agents 1999; 12:97-105. [PMID: 10418753 DOI: 10.1016/s0924-8579(99)00044-8] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Abstract
The mortality rate resulting from severe bacterial sepsis, particularly that associated with shock, still approaches 50% in spite of appropriate antimicrobial therapy and optimum supportive care. Bacterial endotoxins that are part of the cell wall are one of the cofactors in the pathogenesis of sepsis and septic shock and are often induced by antimicrobial chemotherapy even if it is administered rationally. Not all antimicrobial agents are equally capable of inducing septic shock; this is dependant on their mechanism of action rather than on the causative pathogen species. The quantity of endotoxin released depends on the drug dose and whether filaments or spheroplast formation predominates. Some antibiotics such as carbapenems, ceftriaxone, cefepime, glycopeptides, aminoglycosides and quinolones do not have the propensity to provoke septic shock because their rapid bactericidal activity induces mainly spheroplast or fragile spheroplast-like bacterial forms.
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Affiliation(s)
- P Periti
- Department of Preclinical and Clinical Pharmacology, Università di Firenze, Italy
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Morrison DC, Silverstein R, Luchi M, Shnyra A. Structure-function relationships of bacterial endotoxins. Contribution to microbial sepsis. Infect Dis Clin North Am 1999; 13:313-40. [PMID: 10340169 DOI: 10.1016/s0891-5520(05)70077-5] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
A substantial body of knowledge has emerged over the past several decades concerning the primary and tertiary, and quaternary structure of endotoxic LPS and their contribution to the pathogenesis of gram-negative sepsis; however, important questions remain. Among them are the precise three-dimensional configuration of the LPS macromolecule and the contribution of the quaternary structure to the ability of these potent microbial factors to interact with host humoral and cellular inflammatory mediator systems. Also remaining to be sufficiently addressed is the relative contribution of endotoxin interactions with the host to the overall manifestation of disease and conditions under which such contributions serve as the pivotal event in determining outcome. The answers to these questions can be expected to provide valuable insights into potential novel therapeutic intervention strategies and approaches that will ultimately reduce both morbidity and mortality in infection from gram-negative microbes.
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Affiliation(s)
- D C Morrison
- Department of Medical Research, Saint Luke's-Shawnee Mission Health System, Kansas City, Missouri, USA.
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Periti P, Mazzei T. Antibiotic-induced release of bacterial cell wall components in the pathogenesis of sepsis and septic shock: a review. J Chemother 1998; 10:427-48. [PMID: 9876052 DOI: 10.1179/joc.1998.10.6.427] [Citation(s) in RCA: 40] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022]
Abstract
This article reviews the new criteria for selecting the proper antimicrobial agent and dosage regimen for standard treatment of severe sepsis, with the intention of preventing septic shock. After introducing new concepts on the pathogenesis of sepsis and septic shock, the authors analyze the parameters of betalactam antibacterial activity, the antibiotic-induced release of bacterial endotoxin and the interrelationships between pharmacokinetics and pharmacodynamics of antibiotics in the search for an optimum dosage regimen of antimicrobial mono- or polytherapy for severely ill septic patients admitted to the intensive care unit.
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Affiliation(s)
- P Periti
- Department of Pharmacology, University of Florence, Italy.
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Horii T, Kobayashi M, Nadai M, Ichiyama S, Ohta M. Carbapenem-induced endotoxin release in gram-negative bacterial sepsis rat models. FEMS IMMUNOLOGY AND MEDICAL MICROBIOLOGY 1998; 21:297-302. [PMID: 9753002 DOI: 10.1111/j.1574-695x.1998.tb01177.x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The carbapenem-induced endotoxin release was evaluated using experimental models of gram-negative bacterial sepsis in Wistar rats. Infections with Escherichia coli, Serratia marcescens, Klebsiella pneumoniae, Pseudomonas aeruginosa, Proteus vulgaris and Proteus mirabilis resulted in an increase of the plasma endotoxin concentration after treatment with ceftazidime and carbapenems including imipenem, panipenem, meropenem and biapenem. Except for P. aeruginosa, the plasma endotoxin concentrations after carbapenem treatment were significantly lower than those after ceftazidime treatment. It is noteworthy that treatment of P. aeruginosa sepsis with meropenem or biapenem induced significantly more endotoxin release than other carbapenems and the endotoxin concentrations induced by these carbapenems reached those of ceftazidime treatment. The plasma endotoxin concentrations appeared to correlate with the reduction of platelet counts and the elevation of both glutamic oxaloacetic transaminase and glutamic pyruvic transaminase values.
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Affiliation(s)
- T Horii
- Department of Bacteriology, Nagoya University School of Medicine, Japan.
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Liang AH, Ohno N, Yadomae T. Egg white lysozyme inhibits ceftazidime-induced endotoxin release and filamentation ofEscherichia coli O111:B4. Drug Dev Res 1998. [DOI: 10.1002/(sici)1098-2299(199806/07)44:2/3<70::aid-ddr4>3.0.co;2-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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Kirikae T, Kirikae F, Saito S, Tominaga K, Tamura H, Uemura Y, Yokochi T, Nakano M. Biological characterization of endotoxins released from antibiotic-treated Pseudomonas aeruginosa and Escherichia coli. Antimicrob Agents Chemother 1998; 42:1015-21. [PMID: 9593119 PMCID: PMC105737 DOI: 10.1128/aac.42.5.1015] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
The supernatants taken from Pseudomonas aeruginosa and Escherichia coli cultures in human sera or chemically defined M9 medium in the presence of ceftazidime (CAZ) contained high levels of endotoxin, while those taken from the same cultures in the presence of imipenem (IPM) yielded a very low level of endotoxin. The biological activities of endotoxin in the supernatants were compared with those of phenol water-extracted lipopolysaccharide (LPS). The endotoxin released from the organisms as a result of CAZ treatment (CAZ-released endotoxin) contained a large amount of protein. The protein, however, lacked endotoxic activity, since the endotoxin did not show any in vivo toxic effects in LPS-hyporesponsive C3H/HeJ mice sensitized with D-(+)-galactosamine (GalN) or any activation of C3H/HeJ mouse macrophages in vitro. The activities of CAZ- and IPM-released endotoxin (as assessed by a chromogenic Limulus test) were fundamentally the same as those of P. aeruginosa LPS, since their regression lines were parallel. The CAZ-released endotoxin was similar to purified LPS with respect to the following biological activities in LPS-responsive C3H/HeN mice and LPS-hyporesponsive C3H/HeJ mice: lethal toxicity in GalN-sensitized mice, in vitro induction of tumor necrosis factor- and NO production by macrophages, and mitogen-activated protein kinase activation in macrophages. The macrophage activation by CAZ-released endotoxin as well as LPS was mainly dependent on the presence of serum factor and CD14 antigen. Polymyxin B blocked the activity. These findings indicate that the endotoxic activity of CAZ-released endotoxin is due primarily to LPS (lipid A).
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Affiliation(s)
- T Kirikae
- Department of Microbiology, Jichi Medical School, Japan.
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Kirikae T, Hirata M, Yamasu H, Kirikae F, Tamura H, Kayama F, Nakatsuka K, Yokochi T, Nakano M. Protective effects of a human 18-kilodalton cationic antimicrobial protein (CAP18)-derived peptide against murine endotoxemia. Infect Immun 1998; 66:1861-8. [PMID: 9573062 PMCID: PMC108136 DOI: 10.1128/iai.66.5.1861-1868.1998] [Citation(s) in RCA: 85] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/1997] [Accepted: 02/02/1998] [Indexed: 02/07/2023] Open
Abstract
CAP18 (an 18-kDa cationic antimicrobial protein) is a granulocyte-derived protein that can bind lipopolysaccharide (LPS) and inhibit various activities of LPS in vitro. The present study examined the protective effect of a synthetic 27-amino-acid peptide (CAP18(109-135)) from the LPS-binding domain of CAP18 against antibiotic-induced endotoxin shock, using highly LPS-sensitive D-(+)-galactosamine (D-GalN)-sensitized C3H/HeN mice. The antibiotic-induced endotoxin (CAZ-endotoxin) was prepared from the culture filtrate of Pseudomonas aeruginosa PAO1 exposed to ceftazidime (CAZ). Injection of CAP18(109-135) protected the mice injected with LPS or CAZ-endotoxin from death and lowered their tumor necrosis factor (TNF) levels in serum in a dose-dependent manner. Treatment with CAZ caused death of the D-GalN-sensitized P. aeruginosa PAO-infected mice within 48 h, while injection with CAP18(109-135) rescued the mice from death. In the mice rescued from death by injection with CAP18(109-135), endotoxin levels in plasma and TNF production by liver tissues were decreased but the numbers of viable infecting bacteria in their blood were not decreased significantly and remained at the levels in CAZ-treated mice. These results indicate that CAP18(109-135) is capable of preventing antibiotic-induced endotoxic shock in mice with septicemia and that the effect is due to its LPS-neutralizing activity rather than to its antibacterial activity.
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Affiliation(s)
- T Kirikae
- Department of Microbiology, Jichi Medical School, Tochigi-ken, Japan.
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Kirikae T, Nakano M, Morrison DC. Antibiotic-induced endotoxin release from bacteria and its clinical significance. Microbiol Immunol 1997; 41:285-94. [PMID: 9159401 DOI: 10.1111/j.1348-0421.1997.tb01203.x] [Citation(s) in RCA: 41] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Affiliation(s)
- T Kirikae
- Department of Microbiology, Jichi Medical School, Kawachi-gun, Tochigi, Japan
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