The Experts below are selected from a list of 201 Experts worldwide ranked by ideXlab platform
Edward E. Ishiguro - One of the best experts on this subject based on the ideXlab platform.
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temperature sensitivity of Bacteriolysis induced by β lactam antibiotics in amino acid deprived escherichia coli
Journal of Bacteriology, 1998Co-Authors: Dmitrii G. Rodionov, Edward E. IshiguroAbstract:The temperature-sensitive penicillin tolerance response previously reported in amino acid-deprived Escherichia coli (W. Kusser and E. E. Ishiguro, J. Bacteriol. 169:2310–2312, 1987) was not due to the induction of the heat shock response resulting from a temperature upshift and was therefore unrelated to the findings of another report (J. K. Powell and K. D. Young, J. Bacteriol. 173:4021–4026, 1991) indicating a positive correlation between the expression of heat shock proteins and penicillin tolerance. The thermosensitive event occurred in the lysis induction stage.
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Ampicillin-induced Bacteriolysis of Escherichia coli is not affected by reduction in levels of anionic phospholipids
Fems Microbiology Letters, 1997Co-Authors: Dmitrii G. Rodionov, Edward E. IshiguroAbstract:Anionic phospholipids have been shown to interact with both membrane-associated proteins and integral membrane proteins. The objective of this work was to determine whether Bacteriolysis induced by treatment with ampicillin was influenced by the levels of anionic membrane phospholipids in Escherichia coli strain HDL11. The pgsA gene, encoding phosphatidylglycerophosphate synthase, in HDL11 is under the control of lacOP, and the levels of anionic membrane phospholipids are consequently dependent on IPTG. The results indicate that limiting the amounts of phosphatidylglycerol and cardiolipin did not affect the lysis process in both growing and nongrowing bacteria.
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beta lactam induced Bacteriolysis of amino acid deprived escherichia coli is dependent on phospholipid synthesis
Journal of Bacteriology, 1995Co-Authors: Dmitrii G. Rodionov, A G Pisabarro, M A De Pedro, W Kusser, Edward E. IshiguroAbstract:The penicillin tolerance of amino acid-deprived relA+ Escherichia coli is attributed to the stringent response; i.e., relaxation of the stringent response suppresses penicillin tolerance. The beta-lactam-induced lysis of amino acid-deprived bacteria resulting from relaxation of the stringent response was inhibited by cerulenin, or by glycerol deprivation in the case of a gpsA mutant (defective in the biosynthetic sn-glycerol 3-phosphate dehydrogenase). Therefore, beta-lactam-induced lysis of amino acid-deprived cells was dependent on phospholipid synthesis. The lysis process during amino acid deprivation can be experimentally dissociated into two stages designated the priming stage (during which the interaction between the beta-lactam and the penicillin-binding proteins occurs) and the beta-lactam-independent lysis induction stage. Both stages were shown to require phospholipid synthesis. It has been known for some time that the inhibition of phospholipid synthesis is among the plethora of physiological changes resulting from the stringent response. These results indicate that the inhibition of peptidoglycan synthesis and the penicillin tolerance associated with the stringent response are both secondary consequences of the inhibition of phospholipid synthesis.
Isaac Ginsburg - One of the best experts on this subject based on the ideXlab platform.
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Are cationic antimicrobial peptides also ‘double-edged swords’?
Expert Review of Anti-infective Therapy, 2020Co-Authors: Isaac Ginsburg, Erez KorenAbstract:The present view focuses on the possibility that cationic antimicrobial peptides (CAMPs) might, in addition to their killing effects due to permeabilization of microbial membranes, also function similarly to β-lactam antibiotics to activate nascent autolytic wall enzymes, leading to Bacteriolysis. Since the massive release of microbial cell wall components is a major cause of postinfectious sequelae, the in vivo process of Bacteriolysis must be controlled. Due to the emergence of antibiotic resistance in pathogenic bacteria, CAMPs might be useful as an alternative to antibiotics. However, they should be used with caution, since they might also function as a ‘double-edged sword’ by injuring both the bacteria and host.
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Bacteriolysis a mere laboratory curiosity
Critical Reviews in Microbiology, 2018Co-Authors: Isaac Ginsburg, Erez KorenAbstract:The role of Bacteriolysis in the pathophysiology of microbial infections dates back to 1893 when Buchner and Pfeiffer reported for the first time the lysis of bacteria by immune serum and related this phenomenon to the immune response. Later on, basic anti-microbial peptides and certain beta-lactam antibiotics have been shown not only to kill microorganisms but also to induce Bacteriolysis and the release of cell-wall components.In 2009, a novel paradigm was offered suggesting that the main cause of death in sepsis is due to the exclusive release from activated human phagocytic neutrophils (PMNs) traps adhering upon endothelial cells of highly toxic nuclear histone. Since activated PMNs also release a plethora of pro-inflammatory agonists, it stands to reason that these may act in synergy with histone to damage cells. Since certain beta lactam antibiotics may induce Bacteriolysis, it is questioned whether these may aggravate sepsis patient's condition. Enigmatically, since the term Bacteriolysis a...
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Bacteriolysis – a mere laboratory curiosity?
Critical Reviews in Microbiology, 2018Co-Authors: Isaac Ginsburg, Erez KorenAbstract:The role of Bacteriolysis in the pathophysiology of microbial infections dates back to 1893 when Buchner and Pfeiffer reported for the first time the lysis of bacteria by immune serum and related this phenomenon to the immune response. Later on, basic anti-microbial peptides and certain beta-lactam antibiotics have been shown not only to kill microorganisms but also to induce Bacteriolysis and the release of cell-wall components.In 2009, a novel paradigm was offered suggesting that the main cause of death in sepsis is due to the exclusive release from activated human phagocytic neutrophils (PMNs) traps adhering upon endothelial cells of highly toxic nuclear histone. Since activated PMNs also release a plethora of pro-inflammatory agonists, it stands to reason that these may act in synergy with histone to damage cells. Since certain beta lactam antibiotics may induce Bacteriolysis, it is questioned whether these may aggravate sepsis patient's condition. Enigmatically, since the term Bacteriolysis a...
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bactericidal cationic peptides can also function as Bacteriolysis inducing agents mimicking beta lactam antibiotics it is enigmatic why this concept is consistently disregarded
Medical Hypotheses, 2004Co-Authors: Isaac GinsburgAbstract:Abstract Although there is a general consensus that highly cationic peptides kill bacteria primarily by injuring their membranes, an additional hypothesis is proposed suggesting that a large variety of cationic peptides might also render bacteria non viable by activating their autolytic wall enzymes – muramidases (a "Trojan Horse" phenomenon), resulting in Bacteriolysis. This group of cationic peptides includes: lysozyme, lactoferrin, neutrophil-derived permeability increasing peptides, defensins, elastase, cathepsin G, and secretory phopholipase A 2 . In this respect, cationic peptides mimic the bactericidal/bacteriolytic effects exerted by of beta-lactam antibiotics. Bacteriolysis results in a massive release of the pro-inflammatory cell-wall components, endotoxin (LPS), lipoteichoic acid (LTA) and peptidoglycan (PPG), which if not effectively controlled, can trigger the coagulation and complement cascades, the release from phagocytes of inflammatory cytokines, reactive oxygen and nitrogen species, and proteinases. Synergism (a "cross-talk") among such agonists released following Bacteriolysis, is probably the main cause for septic shock and multiple organ failure. It is proposed that a use of Bacteriolysis-inducing antibiotics should be avoided in bacteremic patients and particularly in those patients already suspected of developing shock symptoms as these might further enhance Bacteriolysis and the release of LPS, LTA and PPG. Furthermore, in additonal to the supportive regimen exercised in intensive care settings, a use of non Bacteriolysis-inducing antibiotics when combined with highly sulfated compounds (e.g. heparin, and other clinically certified polysufates) should be considered instead, as these might prevent the activation of the microbial own autolytic systems induced either by highly cationic peptides released by activated phagocytes or by the highly bacteriolytic beta-lactams. Polysulfates might also depress the deleterious effects of the complement cascade and the use of combinations among anti-oxidants ( N -acetyl cysteine), proteinase inhibitors and phospholipids might prove effective to depress the synergistic cytotoxic effects induced by inflammatory agonists. Also, a use of gamma globulin enriched either in anti-LPS or in anti-LTA activities might serve to prevent the binding of these toxins to receptors upon macrophage which upon activation generate inflammatory cytokines. Thus, a use of "cocktails" of anti-inflammatory agents might replace the unsuccessful use of single antagonists proven in scores of clinical trials of sepsis to by ineffective in prolonging the lives of patients. It is enigmatic why the concept, and the publications which support a role for cationic peptides also as potent inducers of Bacteriolysis, an arch evil and a deleterious phenomenon which undoubtedly plays a pivotal role in the pathophysiology of post-infectious sequelae, has been consistently disregarded.
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the role of Bacteriolysis in the pathophysiology of inflammation infection and post infectious sequelae
Apmis, 2002Co-Authors: Isaac GinsburgAbstract:The literature dealing with the biochemical basis of Bacteriolysis and its role in inflammation, infection and in post-infectious sequelae is reviewed and discussed. Bacteriolysis is an event that may occur when normal microbial multiplication is altered due to an uncontrolled activation of a series of autolytic cell-wall breaking enzymes (muramidases). While a low-level Bacteriolysis sometimes occurs physiologically, due to “mistakes” in cell separation, a pronounced cell wall breakdown may occur following Bacteriolysis induced either by beta-lactam antibiotics or by a large variety of Bacteriolysis-inducing cationic peptides. These include spermine, spermidine, bactericidal peptides defensins, bacterial permeability increasing peptides from neutrophils, cationic proteins from eosinophils, lysozyme, myeloperoxidase, lactoferrin, the highly cationic proteinases elastase and cathepsins, PLA2, and certain synthetic polyamino acids. The cationic agents probably function by deregulating lipoteichoic acid (LTA) in Gram-positive bacteria and phospholipids in Gram-negative bacteria, the presumed regulators of the autolytic enzyme systems (muramidases). When Bacteriolysis occurs in vivo, cell-wall- and -membrane-associated lipopolysaccharide (LPS (endotoxin)), lipoteichoic acid (LTA) and peptidoglycan (PPG), are released. These highly phlogistic agents can act on macrophages, either individually or in synergy, to induce the generation and release of reactive oxygen and nitrogen species, cytotoxic cytokines, hydrolases, proteinases, and also to activate the coagulation and complement cascades. All these agents and processes are involved in the pathophysiology of septic shock and multiple organ failure resulting from severe microbial infections. Bacteriolysis induced in in vitro models, either by polycations or by beta-lactams, could be effectively inhibited by sulfated polysaccharides, by D-amino acids as well as by certain anti-bacteriolytic antibiotics. However, within phagocytic cells in inflammatory sites, Bacteriolysis tends to be strongly inhibited presumably due to the inactivation by oxidants and proteinases of the bacterial muramidases. This might results in a long persistence of non-biodegradable cell-wall components causing granulomatous inflammation. However, persistence of microbial cell walls in vivo may also boost innate immunity against infections and against tumor-cell proliferation. Therapeutic strategies to cope with the deleterious effects of Bacteriolysis in vivo include combinations of autolysin inhibitors with combinations of certain anti-inflammatory agents. These might inhibit the synergistic tissue- and- organ-damaging “cross talks” which lead to septic shock and to additional post-infectious sequelae.
Dmitrii G. Rodionov - One of the best experts on this subject based on the ideXlab platform.
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temperature sensitivity of Bacteriolysis induced by β lactam antibiotics in amino acid deprived escherichia coli
Journal of Bacteriology, 1998Co-Authors: Dmitrii G. Rodionov, Edward E. IshiguroAbstract:The temperature-sensitive penicillin tolerance response previously reported in amino acid-deprived Escherichia coli (W. Kusser and E. E. Ishiguro, J. Bacteriol. 169:2310–2312, 1987) was not due to the induction of the heat shock response resulting from a temperature upshift and was therefore unrelated to the findings of another report (J. K. Powell and K. D. Young, J. Bacteriol. 173:4021–4026, 1991) indicating a positive correlation between the expression of heat shock proteins and penicillin tolerance. The thermosensitive event occurred in the lysis induction stage.
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Ampicillin-induced Bacteriolysis of Escherichia coli is not affected by reduction in levels of anionic phospholipids
Fems Microbiology Letters, 1997Co-Authors: Dmitrii G. Rodionov, Edward E. IshiguroAbstract:Anionic phospholipids have been shown to interact with both membrane-associated proteins and integral membrane proteins. The objective of this work was to determine whether Bacteriolysis induced by treatment with ampicillin was influenced by the levels of anionic membrane phospholipids in Escherichia coli strain HDL11. The pgsA gene, encoding phosphatidylglycerophosphate synthase, in HDL11 is under the control of lacOP, and the levels of anionic membrane phospholipids are consequently dependent on IPTG. The results indicate that limiting the amounts of phosphatidylglycerol and cardiolipin did not affect the lysis process in both growing and nongrowing bacteria.
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Ampicillin-induced Bacteriolysis of is not affected by reduction in levels of anionic phospholipids
Fems Microbiology Letters, 1997Co-Authors: Dmitrii G. Rodionov, E IshiguroAbstract:Anionic phospholipids have been shown to interact with both membrane-associated proteins and integral membrane proteins. The objective of this work was to determine whether Bacteriolysis induced by treatment with ampicillin was influenced by the levels of anionic membrane phospholipids in Escherichia coli strain HDL11. The pgsA gene, encoding phosphatidylglycerophosphate synthase, in HDL11 is under the control of lacOP, and the levels of anionic membrane phospholipids are consequently dependent on IPTG. The results indicate that limiting the amounts of phosphatidylglycerol and cardiolipin did not affect the lysis process in both growing and nongrowing bacteria.
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beta lactam induced Bacteriolysis of amino acid deprived escherichia coli is dependent on phospholipid synthesis
Journal of Bacteriology, 1995Co-Authors: Dmitrii G. Rodionov, A G Pisabarro, M A De Pedro, W Kusser, Edward E. IshiguroAbstract:The penicillin tolerance of amino acid-deprived relA+ Escherichia coli is attributed to the stringent response; i.e., relaxation of the stringent response suppresses penicillin tolerance. The beta-lactam-induced lysis of amino acid-deprived bacteria resulting from relaxation of the stringent response was inhibited by cerulenin, or by glycerol deprivation in the case of a gpsA mutant (defective in the biosynthetic sn-glycerol 3-phosphate dehydrogenase). Therefore, beta-lactam-induced lysis of amino acid-deprived cells was dependent on phospholipid synthesis. The lysis process during amino acid deprivation can be experimentally dissociated into two stages designated the priming stage (during which the interaction between the beta-lactam and the penicillin-binding proteins occurs) and the beta-lactam-independent lysis induction stage. Both stages were shown to require phospholipid synthesis. It has been known for some time that the inhibition of phospholipid synthesis is among the plethora of physiological changes resulting from the stringent response. These results indicate that the inhibition of peptidoglycan synthesis and the penicillin tolerance associated with the stringent response are both secondary consequences of the inhibition of phospholipid synthesis.
Stephen E Girardin - One of the best experts on this subject based on the ideXlab platform.
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intracellular Bacteriolysis triggers a massive apoptotic cell death in shigella infected epithelial cells
Microbes and Infection, 2008Co-Authors: Ivan Tattoli, Luigi Lembofazio, Giulia Nigro, Leticia A M Carneiro, Elisabetta Ferraro, Giacomo Rossi, Maria Celeste Martino, Maria Egle De Stefano, Francesco Cecconi, Stephen E GirardinAbstract:Abstract Infected epithelial cells, which act as a first barrier against pathogens, seldom undergo apoptosis. Rather, infected epithelial cells undergo a slow cell death that displays hallmarks of necrosis. Here, we demonstrate that rapid intracellular lysis of Shigella flexneri , provoked by either the use of a diaminopimelic acid auxotroph mutant or treatment of infected cells with antibiotics of the β-lactam family, resulted in a massive and rapid induction of apoptotic cell death. This intracellular Bacteriolysis-mediated apoptotic death (IBAD) was characterized by the specific involvement of the mitochondrial-dependent cytochrome c /Apaf-1 axis that resulted in the activation of caspases-3, -6 and -9. Importantly, Bcl-2 family members and the NF-κB pathway seemed to be critical modulators of IBAD. Finally, we identified that IBAD was also triggered by Salmonella enterica serovar Typhimurium but not by the Gram-positive bacteria, Listeria monocytogenes . Together, our results demonstrate that, contrary to previous findings, epithelial cells are intrinsically able to mount an efficient apoptotic cell death response following infection. Indeed, apoptosis in normal circumstances is masked by powerful anti-apoptotic mechanisms, which are overcome in IBAD. Our results also uncover an unexpected consequence of the treatment of infected cells with certain classes of antibiotics.
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Intracellular Bacteriolysis triggers a massive apoptotic cell death in Shigella-infected epithelial cells.
Microbes and infection, 2008Co-Authors: Ivan Tattoli, Giulia Nigro, Leticia A M Carneiro, Elisabetta Ferraro, Giacomo Rossi, Maria Celeste Martino, Maria Egle De Stefano, Francesco Cecconi, Luigi Lembo-fazio, Stephen E GirardinAbstract:Infected epithelial cells, which act as a first barrier against pathogens, seldom undergo apoptosis. Rather, infected epithelial cells undergo a slow cell death that displays hallmarks of necrosis. Here, we demonstrate that rapid intracellular lysis of Shigella flexneri, provoked by either the use of a diaminopimelic acid auxotroph mutant or treatment of infected cells with antibiotics of the beta-lactam family, resulted in a massive and rapid induction of apoptotic cell death. This intracellular Bacteriolysis-mediated apoptotic death (IBAD) was characterized by the specific involvement of the mitochondrial-dependent cytochrome c/Apaf-1 axis that resulted in the activation of caspases-3, -6 and -9. Importantly, Bcl-2 family members and the NF-kappaB pathway seemed to be critical modulators of IBAD. Finally, we identified that IBAD was also triggered by Salmonella enterica serovar Typhimurium but not by the Gram-positive bacteria, Listeria monocytogenes. Together, our results demonstrate that, contrary to previous findings, epithelial cells are intrinsically able to mount an efficient apoptotic cell death response following infection. Indeed, apoptosis in normal circumstances is masked by powerful anti-apoptotic mechanisms, which are overcome in IBAD. Our results also uncover an unexpected consequence of the treatment of infected cells with certain classes of antibiotics.
Suparna Mukherji - One of the best experts on this subject based on the ideXlab platform.
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beta lactam antibiotics induced Bacteriolysis on lspr sensors for assessment of antimicrobial resistance and quantification of antibiotics
Sensors and Actuators B-chemical, 2020Co-Authors: Kapil Sadani, Suparna MukherjiAbstract:Abstract Antimicrobial resistance affecting humans is fueled by empirical infection diagnostics and continuous unintended antibiotics exposure. A localized surface plasmon resonance (LSPR) based optical fiber biosensor for capture of bacteria followed by antibiotic mediated lysis has been demonstrated for quick drug susceptibility testing. The concept has been proven with P. aeruginosa and E. coli suspended in simulated human urine for potential drug susceptibility testing for urinary tract infections. P. aeruginosa RS1 was found to be selectively sensitive to commonly used third generation cephalosporins ceftazidime, ceftriaxone and cefotaxime. Hence, in an alternate scheme, Bacteriolysis signatures of P. aeruginosa immobilized on gold nanoparticles modified optical fibers was used for quantification of third generation cephalosporins over a linear range of 0.01 to 1 μg/ml, R2 = 0.985, in water. Further, this principle was established for therapeutic drug monitoring (TDM) of the said antibiotics in real human serum in the therapeutic relevant range of 0.5 to 10 μg /mL (R2 = 0.987). This sensor provides a quick alternative to cumbersome Kirby-Bauer disk diffusion tests, practiced in most community health settings and tertiary care hospitals for drug susceptibility testing. The sensor also provides an alternative to chromatography coupled mass spectroscopic techniques for quicker, affordable and possibly point of care antibiotic quantification with applications in environmental and therapeutic monitoring.