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Hernández-Navarro L, Asker M, Rucklidge AM, Mobilia M. Coupled environmental and demographic fluctuations shape the evolution of cooperative antimicrobial resistance. J R Soc Interface 2023; 20:20230393. [PMID: 37907094 PMCID: PMC10618063 DOI: 10.1098/rsif.2023.0393] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2023] [Accepted: 10/06/2023] [Indexed: 11/02/2023] Open
Abstract
There is a pressing need to better understand how microbial populations respond to antimicrobial drugs, and to find mechanisms to possibly eradicate antimicrobial-resistant cells. The inactivation of antimicrobials by resistant microbes can often be viewed as a cooperative behaviour leading to the coexistence of resistant and sensitive cells in large populations and static environments. This picture is, however, greatly altered by the fluctuations arising in volatile environments, in which microbial communities commonly evolve. Here, we study the eco-evolutionary dynamics of a population consisting of an antimicrobial-resistant strain and microbes sensitive to antimicrobial drugs in a time-fluctuating environment, modelled by a carrying capacity randomly switching between states of abundance and scarcity. We assume that antimicrobial resistance (AMR) is a shared public good when the number of resistant cells exceeds a certain threshold. Eco-evolutionary dynamics is thus characterised by demographic noise (birth and death events) coupled to environmental fluctuations which can cause population bottlenecks. By combining analytical and computational means, we determine the environmental conditions for the long-lived coexistence and fixation of both strains, and characterise a fluctuation-driven AMR eradication mechanism, where resistant microbes experience bottlenecks leading to extinction. We also discuss the possible applications of our findings to laboratory-controlled experiments.
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Affiliation(s)
- Lluís Hernández-Navarro
- Department of Applied Mathematics, School of Mathematics, University of Leeds, Leeds LS2 9JT, UK
| | - Matthew Asker
- Department of Applied Mathematics, School of Mathematics, University of Leeds, Leeds LS2 9JT, UK
| | - Alastair M. Rucklidge
- Department of Applied Mathematics, School of Mathematics, University of Leeds, Leeds LS2 9JT, UK
| | - Mauro Mobilia
- Department of Applied Mathematics, School of Mathematics, University of Leeds, Leeds LS2 9JT, UK
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Qin S, Lv D, Duan R, Zheng X, Bukai A, Lu X, Duan Q, Yu M, Jing H, Wang X. Case report: A case of brucellosis misdiagnosed as coronavirus disease 2019/influenza in China. Front Public Health 2023; 11:1186800. [PMID: 37724314 PMCID: PMC10505428 DOI: 10.3389/fpubh.2023.1186800] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2023] [Accepted: 08/14/2023] [Indexed: 09/20/2023] Open
Abstract
Brucellosis is an important zoonosis and a multisystem disease. The signs and symptoms of brucellosis are not specific. In the clinical, brucellosis is often ignored and misdiagnosed. We report a case of brucellosis who was misdiagnosed as coronavirus disease 2019 (COVID-19)/influenza and received delayed treatment during strict COVID-19 control. The neglect of other diseases due to COVID-19 and empirical diagnosis and treatment by medical staff are part of the reasons for misdiagnosis. Otherwise, the normal erythrocyte sedimentation rate (ESR), increased white blood cell count (WBC), and increased neutrophil count (NEUT) of this patient was also a cause of misdiagnosis, which is an important reminder for diagnosis. For patients with the unknown origin of fever and other symptoms related to brucellosis, especially those from endemic areas of brucellosis, brucellosis screening is a priority item, and grassroots doctors should be vigilant and standardize the diagnosis and treatment based on epidemiology history, clinical manifestation, and laboratory tests according to the diagnostic criteria of brucellosis.
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Affiliation(s)
- Shuai Qin
- State Key Laboratory of Infectious Disease Prevention and Control, National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, China
| | - Dongyue Lv
- State Key Laboratory of Infectious Disease Prevention and Control, National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, China
| | - Ran Duan
- State Key Laboratory of Infectious Disease Prevention and Control, National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, China
| | - Xiaojin Zheng
- Akesai Kazak Autonomous County Center for Disease Control and Prevention, Jiuquan, China
| | - Asaiti Bukai
- Akesai Kazak Autonomous County Center for Disease Control and Prevention, Jiuquan, China
| | - Xinmin Lu
- Akesai Kazak Autonomous County Center for Disease Control and Prevention, Jiuquan, China
| | - Qun Duan
- State Key Laboratory of Infectious Disease Prevention and Control, National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, China
| | - Mingrun Yu
- Taizhou Center for Disease Control and Prevention, Taizhou, China
| | - Huaiqi Jing
- State Key Laboratory of Infectious Disease Prevention and Control, National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, China
| | - Xin Wang
- State Key Laboratory of Infectious Disease Prevention and Control, National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, China
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Yan G, Liu Y, Xie M, Shi J, Qiao W, Dong N. Experimental and computational models for tissue-engineered heart valves: a narrative review. BIOMATERIALS TRANSLATIONAL 2021; 2:361-375. [PMID: 35837412 PMCID: PMC9255799 DOI: 10.12336/biomatertransl.2021.04.009] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/30/2021] [Revised: 11/26/2021] [Accepted: 12/03/2021] [Indexed: 11/25/2022]
Abstract
Valvular heart disease is currently a common problem which causes high morbidity and mortality worldwide. Prosthetic valve replacements are widely needed to correct narrowing or backflow through the valvular orifice. Compared to mechanical valves and biological valves, tissue-engineered heart valves can be an ideal substitute because they have a low risk of thromboembolism and calcification, and the potential for remodelling, regeneration, and growth. In order to test the performance of these heart valves, various animal models and other models are needed to optimise the structure and function of tissue-engineered heart valves, which may provide a potential mechanism responsible for substantial enhancement in tissue-engineered heart valves. Choosing the appropriate model for evaluating the performance of the tissue-engineered valve is important, as different models have their own advantages and disadvantages. In this review, we summarise the current state-of-the-art animal models, bioreactors, and computational simulation models with the aim of creating more strategies for better development of tissue-engineered heart valves. This review provides an overview of major factors that influence the selection and design of a model for tissue-engineered heart valve. Continued efforts in improving and testing models for valve regeneration remain crucial in basic science and translational researches. Future research should focus on finding the right animal model and developing better in vitro testing systems for tissue-engineered heart valve.
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Affiliation(s)
| | | | | | | | - Weihua Qiao
- Corresponding authors: Weihua Qiao, ; Nianguo Dong,
| | - Nianguo Dong
- Corresponding authors: Weihua Qiao, ; Nianguo Dong,
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4
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Akiyama T, Kim M. Stochastic response of bacterial cells to antibiotics: its mechanisms and implications for population and evolutionary dynamics. Curr Opin Microbiol 2021; 63:104-108. [PMID: 34325154 DOI: 10.1016/j.mib.2021.07.002] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2021] [Revised: 06/22/2021] [Accepted: 07/01/2021] [Indexed: 11/20/2022]
Abstract
The effectiveness of antibiotics against bacterial infections has been declining due to the emergence of resistance. Precisely understanding the response of bacteria to antibiotics is critical to maximizing antibiotic-induced bacterial eradication while minimizing the emergence of antibiotic resistance. Cell-to-cell heterogeneity in antibiotic susceptibility is observed across various bacterial species for a wide range of antibiotics. Heterogeneity in antibiotic susceptibility is not always due to the genetic differences. Rather, it can be caused by non-genetic mechanisms such as stochastic gene expression and biased partitioning upon cell division. Heterogeneous susceptibility leads to the stochastic growth and death of individual cells and stochastic fluctuations in population size. These fluctuations have important implications for the eradication of bacterial populations and the emergence of genotypic resistance.
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Affiliation(s)
- Tatsuya Akiyama
- Department of Physics, Emory University, Atlanta, GA, 30322, USA; Graduate Division of Biological and Biomedical Sciences, Emory University, Atlanta, GA, 30322, USA
| | - Minsu Kim
- Department of Physics, Emory University, Atlanta, GA, 30322, USA; Graduate Division of Biological and Biomedical Sciences, Emory University, Atlanta, GA, 30322, USA; Emory Antibiotic Resistance Center, Emory University, Atlanta, GA, 30322, USA.
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5
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Coates J, Park BR, Le D, Şimşek E, Chaudhry W, Kim M. Antibiotic-induced population fluctuations and stochastic clearance of bacteria. eLife 2018; 7:32976. [PMID: 29508699 PMCID: PMC5847335 DOI: 10.7554/elife.32976] [Citation(s) in RCA: 39] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2017] [Accepted: 02/15/2018] [Indexed: 01/22/2023] Open
Abstract
Effective antibiotic use that minimizes treatment failures remains a challenge. A better understanding of how bacterial populations respond to antibiotics is necessary. Previous studies of large bacterial populations established the deterministic framework of pharmacodynamics. Here, characterizing the dynamics of population extinction, we demonstrated the stochastic nature of eradicating bacteria with antibiotics. Antibiotics known to kill bacteria (bactericidal) induced population fluctuations. Thus, at high antibiotic concentrations, the dynamics of bacterial clearance were heterogeneous. At low concentrations, clearance still occurred with a non-zero probability. These striking outcomes of population fluctuations were well captured by our probabilistic model. Our model further suggested a strategy to facilitate eradication by increasing extinction probability. We experimentally tested this prediction for antibiotic-susceptible and clinically-isolated resistant bacteria. This new knowledge exposes fundamental limits in our ability to predict bacterial eradication. Additionally, it demonstrates the potential of using antibiotic concentrations that were previously deemed inefficacious to eradicate bacteria.
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Affiliation(s)
- Jessica Coates
- Microbiology and Molecular Genetics Graduate Program, Graduate Division of Biological and Biomedical Sciences, Emory University, Atlanta, United States
| | - Bo Ryoung Park
- Department of Physics, Emory University, Atlanta, United States
| | - Dai Le
- Department of Physics, Emory University, Atlanta, United States
| | - Emrah Şimşek
- Department of Physics, Emory University, Atlanta, United States
| | - Waqas Chaudhry
- Department of Physics, Emory University, Atlanta, United States
| | - Minsu Kim
- Microbiology and Molecular Genetics Graduate Program, Graduate Division of Biological and Biomedical Sciences, Emory University, Atlanta, United States.,Department of Physics, Emory University, Atlanta, United States.,Emory Antibiotic Resistance Center, Emory University, Atlanta, United States
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6
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Affiliation(s)
- Diarmaid Hughes
- Department of Medical Biochemistry and Microbiology, Uppsala University, 751 23 Uppsala, Sweden
| | - Dan I. Andersson
- Department of Medical Biochemistry and Microbiology, Uppsala University, 751 23 Uppsala, Sweden
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7
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Sommer MOA, Munck C, Toft-Kehler RV, Andersson DI. Prediction of antibiotic resistance: time for a new preclinical paradigm? Nat Rev Microbiol 2017; 15:689-696. [DOI: 10.1038/nrmicro.2017.75] [Citation(s) in RCA: 164] [Impact Index Per Article: 23.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
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8
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Andersson D. Improving predictions of the risk of resistance development against new and old antibiotics. Clin Microbiol Infect 2015; 21:894-8. [DOI: 10.1016/j.cmi.2015.05.012] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2015] [Revised: 05/06/2015] [Accepted: 05/08/2015] [Indexed: 11/24/2022]
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9
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Hughes D, Andersson DI. Evolutionary consequences of drug resistance: shared principles across diverse targets and organisms. Nat Rev Genet 2015; 16:459-71. [DOI: 10.1038/nrg3922] [Citation(s) in RCA: 165] [Impact Index Per Article: 18.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
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10
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Abstract
In addition to their impressive, well-publicized and well-researched propensity to evolve and acquire genetically determined mechanisms for resistance to antibiotics, bacteria that are inherently susceptible to these drugs can also be phenotypically refractory to their action. This phenomenon of 'non-inherited resistance' to antibiotics has been known since the beginning of the antibiotic era but, relative to inherited resistance, it has been given little attention. Here, we review the in vitro and in vivo evidence for the different forms of non-inherited resistance and the mechanisms responsible. With the aid of a simple mathematical model and computer simulations, we show how non-inherited resistance could extend the duration of antibiotic treatment, cause treatment failure and promote the generation and ascent of inherited resistance in treated patients.
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Affiliation(s)
- Bruce R Levin
- Department of Biology, Emory University, Atlanta, Georgia 30307, USA.
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11
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HARRIS H. Mobilization of defensive cells in inflammatory tissue. BACTERIOLOGICAL REVIEWS 1998; 24:3-15. [PMID: 14399954 PMCID: PMC441033 DOI: 10.1128/br.24.1.3-15.1960] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Key Words] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
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12
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13
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Gortvai P, De Louvois J, Hurley R. The bacteriology and chemotherapy of acute pyogenic brain abscess. Br J Neurosurg 1987; 1:189-203. [PMID: 3267286 DOI: 10.3109/02688698709035304] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Affiliation(s)
- P Gortvai
- Regional Centre for Neurosurgery, Oldchurch Hospital, London, England
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14
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Casey SG, Shafer WM, Spitznagel JK. Anaerobiosis increases resistance of Neisseria gonorrhoeae to O2-independent antimicrobial proteins from human polymorphonuclear granulocytes. Infect Immun 1985; 47:401-7. [PMID: 3917976 PMCID: PMC263183 DOI: 10.1128/iai.47.2.401-407.1985] [Citation(s) in RCA: 25] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
We investigated the in vitro resistance of Neisseria gonorrhoeae FA19 to the O2-independent antimicrobial systems of human polymorphonuclear leukocytes. Acid extracts of polymorphonuclear leukocyte granules (crude granule extracts) and a purified granule protein (57 kilodaltons) were, at low concentrations, bactericidal for gonococci under aerobic conditions that permitted growth. However, they were less effective under anaerobic conditions that imposed bacteriostasis. We found that adding sodium nitrite to reduced growth media permitted the growth of strain FA19 in an anaerobic environment. Under these conditions with nitrite, anaerobic cultures of strain FA19 were no more resistant to the crude granule extract and the 57-kilodalton protein than aerobic cultures. In contrast, Salmonella typhimurium SL-1004, a facultative anaerobe, was readily killed by both the crude granule extract and the 57-kilodalton antimicrobial protein regardless of the presence or absence of free molecular oxygen. This is the first demonstration that an isolated antimicrobial protein from polymorphonuclear leukocyte granules is active against bacteria under anaerobic conditions. Our results also indicated that the efficacy of human polymorphonuclear leukocyte O2-independent killing of N. gonorrhoeae may, in part, be inhibited by bacteriostatic conditions imposed by hypoxia.
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15
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Lam C, Georgopoulos A, Laber G, Schütze E. Therapeutic relevance of penicillin-induced hypersensitivity of Staphylococcus aureus to killing by polymorphonuclear leukocytes. Antimicrob Agents Chemother 1984; 26:149-54. [PMID: 6385837 PMCID: PMC284109 DOI: 10.1128/aac.26.2.149] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
There is an overwhelming body of evidence that certain Staphylococcus aureus strains become more sensitive to killing by polymorphonuclear leukocytes after their growth in media containing subinhibitory concentrations of penicillin. However, it is not clear to what extent this phenomenon contributes to the curative effect of penicillin in vivo. To explore its therapeutic relevance, we evaluated the interaction of staphylococci pretreated with penicillin in vitro with leukocytes in cell-proof diffusion chambers (porosity, 0.22 micron) implanted subcutaneously in rabbits. Under this in vivo environment, staphylococci pretreated with penicillin remained hypersensitive to leukocyte killing as under in vitro conditions. Furthermore, when the staphylococci were mixed with the leukocytes in chambers implanted intraperitoneally in mice which subsequently received intravenously a suboptimal dose of penicillin, they also became hypersensitive to leukocytic killing. However, because the staphylococcal growth rate was considerably reduced in vivo, the degree of penicillin-induced sensitivity to leukocytic killing was smaller than that obtained in test tube cultures; nevertheless, the enhanced killing was significant. Additional support that the curative effect of penicillin partly depends on its synergistic action with the leukocytes was provided by the relative decrease in virulence of staphylococci pretreated with penicillin in mice in which the cellular host defenses were already recruited at the focus of inoculation. These observations indicate that penicillin-induced hypersensitivity of staphylococci to leukocytic killing is not only an in vitro phenomenon, but an effect which has therapeutic relevance.
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16
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17
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Dalhoff A, Frank G, Luckhaus G. The granuloma pouch: an in vivo model for pharmacokinetic and chemotherapeutic investigations. I. Biochemical and histological characterization. Infection 1982; 10:354-60. [PMID: 7152686 DOI: 10.1007/bf01642299] [Citation(s) in RCA: 28] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
The "granuloma pouch" model in rats was evaluated on the basis of biochemical, haematological and histological factors. Seven days after formation of the pouch following the intramuscular injection of air and a mixture of 1% croton oil in olive oil as an irritant, the pouch was filled by approximately 5 ml of haemorrhagic exudate. Biochemical assessment of the exudate revealed that its main characteristics were increased lactate dehydrogenase levels as well as increased alpha 2- and gamma-globulin fractions. Histological sections of the surrounding tissue showed a typical granulomatous inflammatory response. The granuloma pouch can therefore be characterized as a local, chronic inflammation caused by the creation of a body cavity. The biochemical data of the pouch exudate were compared with those of human wound fluid obtained after surgery; since the values were in very good agreement, it is assumed that the granuloma pouch model reflects the clinical situation in inflamed wound cavities following the extirpation of organs.
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18
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Yoshida K, Takahashi M, Narikawa S. Synergistic effect of rabbit specific antiserum and amikacin on the treatment of mice with lethal infection due to Klebsiella pneumoniae. EXPERIENTIA 1981; 37:956-7. [PMID: 7028503 DOI: 10.1007/bf01971775] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
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19
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Rolinson GN. Basis and results of therapy with Beta-lactam antibiotics in experimental infections. Infection 1980; Suppl 1:30-4. [PMID: 7399710 DOI: 10.1007/bf01644932] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
Experimental infections in animals and their chemotherapy are dependent on a variety of experimental conditions and parameters which may be themselves interrelated; the type and number of infecting organisms, the nature of the infection, the antibiotic chosen for therapy and its administration schedule can influence the results of animal studies. One additional factor which applies to dosage of penicillins is the phenomenon of the recovery period, i. e. the period of time which surviving bacteria need to resume growth after removal of the drug. The bactericidal effect probably strongly influences the period of time which is required before the number of viable organisms reach the level present at the time of infection. Thus one can assume that it is the extent of the bactericidal effect which influences the period of time between doses rather than the recovery period. Besides these parameters the physiological state of the infecting organism may also be important. The results of penicillin therapy vary considerably depending on the bacterial growth rate. Differences in the nature of infection in experimental animals and man and the physiology of animals and man do not allow close simulation of clinical infections under experimental conditions. However the factors discussed may provide some guidelines for rational antibiotic treatment in man.
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20
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Ansfield MJ, Woods DE, Johanson WG. Lung bacterial clearance in murine pneumococcal pneumonia. Infect Immun 1977; 17:195-204. [PMID: 18404 PMCID: PMC421101 DOI: 10.1128/iai.17.1.195-204.1977] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
We studied the bactericidal capacity of the rat lung during the development of pneumococcal pneumonia. Pneumonia was produced in a lower lobe by the intrabronchial instillation of 10(4)Streptococcus pneumoniae cells in buffer. Lung bacterial counts progressively increased, reaching 10(7) per lung within 48 h, and the increase was associated with localized atelectasis and consolidation. Bacterial multiplication was inhibited with tetracycline at various intervals after infection, and the subsequent clearance of pneumococci was determined. Viable pneumococci were rapidly killed by lung defenses if bacterial multiplication was inhibited within 12 h of the onset of infection. No change occurred in the bacterial populationif tetracycline was delayed until 24 h after infection, indicating that pneumococcal killing by lung defenses had ceased. This effect could be reproduced with the addition of pneumococcal capsular polysaccharide to the inoculum, which produced a dose-related inhibition of pneumococcal clearance. The clearance of S. epidermidis was not impaired in the presence of pneumococcal pneumonia or by administration of exogenous capsular polysaccharide. These data indicate that pneumococcal pneumonia causes a marked impairment in lung antipneumococcal defenses within 24 h of the onset of infection. This acquired defect in antibacterial defenses may be due to the accumulation of pneumococcal capsular material in the lungs of infected animals.
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21
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Nishida M, Murakawa T. Exudate levels and bactericidal activity of cefazolin in a new local infection system using rat granuloma pouches. Antimicrob Agents Chemother 1977; 11:1042-8. [PMID: 879750 PMCID: PMC352126 DOI: 10.1128/aac.11.6.1042] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
An experimental local infection system has been developed in which exudates are induced with croton oil in granuloma pouches of rats. This system provided a suitable model for the evaluation of the therapeutic effect of two antibiotics, cefazolin and cephalothin. Exudate levels of cefazolin were found to be higher than those of cephalothin, and these levels correlated with the higher serum level of cefazolin. The therapeutic effect of cefazolin, after intramuscular injection of 20 mg of each antibiotic per kg, was superior to that of cephalothin in eradicating both Staphylococcus aureus and Escherichia coli.
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22
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Quartey GR, Johnston JA, Rozdilsky B. Decadron in the treatment of cerebral abscess. An experimental study. J Neurosurg 1976; 45:301-10. [PMID: 948016 DOI: 10.3171/jns.1976.45.3.0301] [Citation(s) in RCA: 70] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Forty rabbits were inoculated with Streptococcus pyogenes or Staphylococcus aureus to produce cerebral abscesses. One-third of the rabbits received no treatment and served as controls. One-third received dexamethasone (Decadron) plus an appropriate antibiotic. One-third received only the appropriate antibiotic in the same dosage. The animals were sacrificed 10 days after inoculation and the brains examined. In the control group, an abscess at the stage of granulation tissue encapsulation containing the inoculated organisms was found. The surrounding brain showed a marked inflammatory response. In the Decadron plus antibiotic group, necrotic lesions were found containing the inoculated organisms and surrounded by relatively normal brain. In the group treated with antibiotic alone, healed glial scars were found in relatively normal brain. Our findings are discussed with reference to the medical literature regarding the influence of glucocorticoids on the inflammatory response and the efficacy of antibiotics when this response is suppressed.
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23
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Bass DA. Behavior of eosinophil leukocytes in acute inflammation. I. Lack of dependence on adrenal function. J Clin Invest 1975; 55:1229-36. [PMID: 1133170 PMCID: PMC301877 DOI: 10.1172/jci108041] [Citation(s) in RCA: 39] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
Acute infection is accompanied by a characteristic reduction in circulating eosinophils. This study examined the generally held assumption that the eosinopenia of infection is a manifestation of adrenal stimulation. Trichinosis, Escherichia coli pyelonephritis, and early subcutaneous pneumococcal abscess were used as experimental infections of limited severity. Trichinosis is associated with eosinophilia, but pyelonephritis and pneumococcal infection produce eosinopenia. An assay for serum corticosterone was developed that is sufficiently sensitive to be performed with the small volumes of blood obtained sequentially from individual mice. The corticosterone response to trichinosis fits the sterotyped reaction previously reported for several other bacterial, viral, and rickettsial infections. The peak concentrations of corticosterone in serum from mice with trichinosis was approximately twice normal and occurred at the onset of clinical illness. Serum corticosterone levels gradually declined to the normal range over the next several days. E. coli pyelonephritis produced a similar adrenal response, although the peak serum corticosterone caused by pyelonephritis was less than the serum corticosterone occurring during the first peak of eosinophilia during trichinosis. Infection of a subcutaneous air pouch with penumococci produced eosinopenia within 6 h after inoculation, but there was no rise in serum corticosterone during the first 12 h of the pneumococcal infection. In addition, the eosinopenic response produced by a 12-hpneumococcal abscess occurred mice adrenalectomized 1-4 days before infection with pneumococci. The eosinopenia of acute infection cannot be ascribed to adrenal stimulation.
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24
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Black P, Graybill JR, Charache P. Penetration of brain abscess by systemically administered antibiotics. J Neurosurg 1973; 38:705-9. [PMID: 4488802 DOI: 10.3171/jns.1973.38.6.0705] [Citation(s) in RCA: 107] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
✓ In six consecutive patients treated with systemic antibiotics for brain abscess, chloramphenicol, methicillin, and penicillin were found capable of penetrating the abscess in therapeutic concentration. Nafcillin, a fourth antibiotic tested, failed to penetrate. While on antibiotics, all six patients continued to deteriorate neurologically until needle aspiration of the abscess was carried out, after which recovery began promptly. Organisms were found in the pus despite the presence of therapeutically effective antibiotic levels, and despite the fact that the organisms were sensitive, in vitro, to the antibiotics used. These observations confirm that antibiotics alone are insufficient and that surgical evacuation of the abscess is essential. The need for local instillation of antibiotics directly into abscesses is questionable since penetration following systemic administration of three antibiotics tested was adequate when blood levels were high. It is suggested that the instillation of penicillin or its derivatives be avoided in view of their potential epileptogenicity as well as the questionable value of this method.
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25
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Ribble JC. Laboratory assistance in the treatment of bacterial infections. Pediatr Clin North Am 1971; 18:115-24, viii. [PMID: 25868178 DOI: 10.1016/s0031-3955(16)32526-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
The microbiology laboratory can assist the clinician in the treatment of bacterial infections by isolating and identifying the responsible organisms and by determining their susceptibility to antibiotic drugs.
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Affiliation(s)
- J C Ribble
- Cornell University Medical College, NY, USA
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26
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Wasielewski EV, Sch�tze E. Die therapie mit antibiotiea unter besonderer ber�cksichtigung ihrer beziehungen zur Hals-Nasen-Ohren-Heilkunde. Eur Arch Otorhinolaryngol 1967. [DOI: 10.1007/bf01278503] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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28
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EXPERIMENTAL STUDIES OF INTRAPLEURAL INJECTION OF SODIUM HEPARIN IN PNEUMONECTOMIZED DOGS WITH AND WITHOUT INFECTION. J Thorac Cardiovasc Surg 1961. [DOI: 10.1016/s0022-5223(20)31907-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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ROGERS DE. Observations on the nature of staphylococcal infections. BULLETIN OF THE NEW YORK ACADEMY OF MEDICINE 1959; 35:25-38. [PMID: 13608176 PMCID: PMC1806035] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 04/23/2023]
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SMITH MR, WOOD WB. An experimental analysis of the curative action of penicillin in acute bacterial infections. II. The role of phagocytic cells in the process of recovery. J Exp Med 1956; 103:499-508. [PMID: 13306858 PMCID: PMC2180356 DOI: 10.1084/jem.103.4.499] [Citation(s) in RCA: 24] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022] Open
Abstract
Type I pneumococci injected into the leg muscles of otherwise normal mice reached a maximum total population of approximately 10(6) organisms. In mice rendered severely leucopenic by previous irradiation the maximum bacterial counts recorded were of the order of 10(9). Since the lesions in the latter animals were relatively acellular, the thousandfold difference in the two experiments represented a rough measure of the antibacterial action of the leucocytic exudate. The suppressive effect of the leucocytic exudate was shown by histologie studies to involve phagocytosis. The ingestion of pneumococci was clearly demonstrable within the first 12 to 18 hours. Accordingly, it was attributed to surface phagocytosis. In support of this conclusion was the finding that type III pneumococci reached a significantly higher total population in the myositis lesions than did type I. The type III strain used had been previously shown to be resistant to surface phagocytosis during active growth, whereas the type I strain was known to be susceptible throughout its growth phase. Evidence was also presented that the dense leucocytic exudate probably caused in addition a significant degree of bacteriostasis. When penicillin therapy was begun 9 hours after inoculation, the pneumococci were cleared from the lesions with equal rapidity regardless of the presence or absence of leucocytic exudate. At this early stage the pneumococci were multiplying rapidly in the lesions of both the irradiated and unirradiated mice and therefore were promptly killed by the direct action of the penicillin. When the start of treatment was delayed, however, until 24 hours after inoculation, the bacteria in both sets of lesions had already reached their maximum counts and therefore were presumably resistant to the bactericidal effect of the antibiotic. Under such circumstances the destruction of the bacteria was found to be significantly less prompt in the acellular lesions than in those with a normal cellular exudate. It is concluded from these findings that, in established pneumococcal myositis in mice, the curative effect of penicillin is due, not to the bactericidal action of the antibiotic alone, but rather to the combined effect of the drug and the cellular defenses of the host. The same conclusion also appears to be applicable to analogous acute infections in man, particularly when they are sufficiently advanced to be definitively diagnosed.
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WOOD WB, SMITH MR. An experimental analysis of the curative action of penicillin in acute bacterial infections. I. The relationship of bacterial growth rates to the antimicrobial effect of penicillin. J Exp Med 1956; 103:487-98. [PMID: 13306857 PMCID: PMC2180349 DOI: 10.1084/jem.103.4.487] [Citation(s) in RCA: 41] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
Three strains of pneumococcus (types I and III), equally sensitive to penicillin, have been shown to be killed by the antibiotic in vitro when grown either in enriched beef infusion broth or in a thin serous exudate. Killing of the bacteria resulted promptly when the penicillin was added during the logarithmic phase of growth but failed to occur if addition of the antibiotic was delayed until the later "stationary" growth phase. In analogous experiments with thick purulent exudates from established subcutaneous abscesses, the pneumococci failed to grow rapidly, and added penicillin exerted only a relatively slow bactericidal effect. The relevance of these in vitro observations to the curative action of penicillin was demonstrated in a systematic histologic study of the antimicrobial effect of the drug in experimental (type I) pneumococcal pneumonia. Evidence was obtained that at least two distinct processes are involved. The first, the direct bactericidal effect of the penicillin itself, was shown to operate in the outer edema zone of the spreading pneumonic lesion where the micro-organisms multiply rapidly in the thin serous exudate. The second, which predominates in the older more central portions of the lesion, was demonstrated to depend upon destruction of the pneumococci by phagocytosis. Here the bacteria, having presumably reached a relatively stationary phase of growth in the alveolar exudate, are resistant to the bactericidal action of the penicillin but are readily destroyed by the phagocytes.
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