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Omar A, El-Banna TE, Sonbol FI, El-Bouseary MM. Potential antivirulence and antibiofilm activities of sub-MIC of oxacillin against MDR S. aureus isolates: an in-vitro and in-vivo study. BMC Microbiol 2024; 24:295. [PMID: 39123138 PMCID: PMC11312681 DOI: 10.1186/s12866-024-03429-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2023] [Accepted: 07/16/2024] [Indexed: 08/12/2024] Open
Abstract
BACKGROUND Multi-drug resistant Staphylococcus aureus is one of the most common causes of nosocomial and community-acquired infections, with high morbidity and mortality. Treatment of such infections is particularly problematic; hence, it is complicated by antibiotic resistance, and there is currently no reliable vaccine. Furthermore, it is well known that S. aureus produces an exceptionally large number of virulence factors that worsen infection. Consequently, the urgent need for anti-virulent agents that inhibit biofilm formation and virulence factors has gained momentum. Therefore, we focused our attention on an already-approved antibiotic and explored whether changing the dosage would still result in the intended anti-virulence effect. METHODS In the present study, we determined the antibiotic resistance patterns and the MICs of oxacillin against 70 MDR S. aureus isolates. We also investigated the effect of sub-MICs of oxacillin (at 1/4 and 1/8 MICs) on biofilm formation using the crystal violet assay, the phenol-sulphuric acid method, and confocal laser scanning microscopy (CLSM). We examined the effect of sub-MICs on virulence factors and bacterial morphology using quantitative reverse transcription polymerase chain reaction (qRT-PCR) and electron microscopy, respectively. Moreover, we studied the effect of sub-MICs of oxacillin (OX) in-vivo using a wound infection model. RESULTS Oxacillin at 1/2 MIC showed a significant decrease in bacterial viability, while 1/4 and 1/8 MICs had negligible effects on treated bacterial isolates. Treatment of MDR isolates with 1/4 or 1/8 MICs of oxacillin significantly reduced biofilm formation (64% and 40%, respectively). The treated MDR S. aureus with sub-MICs of OX exhibited a dramatic reduction in several virulence factors, including protease, hemolysin, coagulase, and toxic shock syndrome toxin-1 (TSST-1) production. The sub-MICs of OX significantly decreased (P < 0.05) the gene expression of biofilm and virulence-associated genes such as agrA, icaA, coa, and tst. Furthermore, oxacillin at sub-MICs dramatically accelerated wound healing, according to the recorded scoring of histological parameters. CONCLUSION The treatment of MDR S. aureus with sub-MICs of oxacillin can help in combating the bacterial resistance and may be considered a promising approach to attenuating the severity of S. aureus infections due to the unique anti-biofilm and anti-virulence activities.
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Affiliation(s)
- Amira Omar
- Department of Microbiology and Immunology, Faculty of Pharmacy, Tanta University, Tanta, Egypt.
| | - Tarek E El-Banna
- Department of Microbiology and Immunology, Faculty of Pharmacy, Tanta University, Tanta, Egypt
| | - Fatma I Sonbol
- Department of Microbiology and Immunology, Faculty of Pharmacy, Tanta University, Tanta, Egypt
| | - Maisra M El-Bouseary
- Department of Microbiology and Immunology, Faculty of Pharmacy, Tanta University, Tanta, Egypt.
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2
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Yue Y, Chen K, Sun C, Ahmed S, Ojha SC. Antimicrobial peptidase lysostaphin at subinhibitory concentrations modulates staphylococcal adherence, biofilm formation, and toxin production. BMC Microbiol 2023; 23:311. [PMID: 37884887 PMCID: PMC10601153 DOI: 10.1186/s12866-023-03052-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2023] [Accepted: 10/09/2023] [Indexed: 10/28/2023] Open
Abstract
BACKGROUND The ability of antimicrobial agents to affect microbial adherence to eukaryotic cell surfaces is a promising antivirulence strategy for combating the global threat of antimicrobial resistance. Inadequate use of antimicrobials has led to widespread instances of suboptimal antibiotic concentrations around infection sites. Therefore, we aimed to examine the varying effect of an antimicrobial peptidase lysostaphin (APLss) on staphylococcal adherence to host cells, biofilm biomass formation, and toxin production as a probable method for mitigating staphylococcal virulence. RESULTS Initially, soluble expression in E. coli and subsequent purification by immobilized-Ni2+ affinity chromatography (IMAC) enabled us to successfully produce a large quantity of highly pure ~ 28-kDa His-tagged mature APLss. The purified protein exhibited potent inhibitory effects against both methicillin-sensitive and methicillin-resistant staphylococcal strains, with minimal inhibitory concentrations (MICs) ranging from 1 to 2 µg/mL, and ultrastructural analysis revealed that APLss-induced concentration-specific changes in the morphological architecture of staphylococcal surface membranes. Furthermore, spectrophotometric and fluorescence microscopy revealed that incubating staphylococcal strains with sub-MIC and MIC of APLss significantly inhibited staphylococcal adherence to human vaginal epithelial cells and biofilm biomass formation. Ultimately, transcriptional investigations revealed that APLss inhibited the expression of agrA (quorum sensing effector) and other virulence genes related to toxin synthesis. CONCLUSIONS Overall, APLss dose-dependently inhibited adhesion to host cell surfaces and staphylococcal-associated virulence factors, warranting further investigation as a potential anti-staphylococcal agent with an antiadhesive mechanism of action using in vivo models of staphylococcal toxic shock syndrome.
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Affiliation(s)
- Yuan Yue
- Department of Infectious Diseases, The Affiliated Hospital of Southwest Medical University, Luzhou, 646000, Sichuan, China
- National Engineering Laboratory for Resource Development of Endangered Crude Drugs in Northwest China, Shaanxi Normal University, Xi'an, China
| | - Ke Chen
- Department of Infectious Diseases, The Affiliated Hospital of Southwest Medical University, Luzhou, 646000, Sichuan, China
- Southwest Medical University, Jiangyang District, Luzhou, 646000, Sichuan, China
| | - Changfeng Sun
- Department of Infectious Diseases, The Affiliated Hospital of Southwest Medical University, Luzhou, 646000, Sichuan, China
- Southwest Medical University, Jiangyang District, Luzhou, 646000, Sichuan, China
| | - Sarfraz Ahmed
- Wellman Centre for Photomedicine, Massachusetts General Hospital, Harvard Medical School, Boston MA 02114, USA
| | - Suvash Chandra Ojha
- Department of Infectious Diseases, The Affiliated Hospital of Southwest Medical University, Luzhou, 646000, Sichuan, China.
- Southwest Medical University, Jiangyang District, Luzhou, 646000, Sichuan, China.
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3
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Zhang L, Esquembre LA, Xia SN, Oesterhelt F, Hughes CC, Brötz-Oesterhelt H, Teufel R. Antibacterial Synnepyrroles from Human-Associated Nocardiopsis sp. Show Protonophore Activity and Disrupt the Bacterial Cytoplasmic Membrane. ACS Chem Biol 2022; 17:2836-2848. [PMID: 36179367 DOI: 10.1021/acschembio.2c00460] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
Actinobacteria have traditionally been an important source of bioactive natural products, although many genera remain poorly explored. Here, we report a group of distinctive pyrrole-containing natural products, named synnepyrroles, from Nocardiopsis synnemataformans. Detailed structural characterization by mass spectrometry and nuclear magnetic resonance (NMR) spectroscopy combined with isotope-labeling experiments revealed their molecular structures and biosynthetic precursors acetate, propionate, aspartate, and (for branched analogues) valine. The biosynthetic data points toward an unusual pathway for pyrrole formation via condensation of aspartate with diverse fatty acids that give rise to a unique pyrrole-3,4-dicarboxylate core and variable linear or terminally branched alkyl side chains. In addition, the bioactivity and mode of action of synnepyrrole A were characterized in Bacillus subtilis. Orienting assessment of the phenotype of synnepyrrole A-treated bacteria by high-resolution microscopy suggested the cytoplasmic membrane as the target structure. Further characterization of the membrane effects demonstrated dissipation of the membrane potential and intracellular acidification indicative of protonophore activity. At slightly higher concentrations, synnepyrrole A compromised the barrier function of the cytoplasmic membrane, allowing the passage of otherwise membrane-impermeable dye molecules.
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Affiliation(s)
- Lei Zhang
- Faculty of Biology, University of Freiburg, Schänzlestrasse 1, 79104 Freiburg, Germany
| | - Lidia Alejo Esquembre
- Department of Microbial Bioactive Compounds, Interfaculty Institute for Microbiology and Infection Medicine, University of Tübingen, 72076 Tübingen, Germany
| | - Shu-Ning Xia
- Department of Microbial Bioactive Compounds, Interfaculty Institute for Microbiology and Infection Medicine, University of Tübingen, 72076 Tübingen, Germany
| | - Filipp Oesterhelt
- Department of Microbial Bioactive Compounds, Interfaculty Institute for Microbiology and Infection Medicine, University of Tübingen, 72076 Tübingen, Germany
| | - Chambers C Hughes
- Department of Microbial Bioactive Compounds, Interfaculty Institute for Microbiology and Infection Medicine, University of Tübingen, 72076 Tübingen, Germany.,Cluster of Excellence EXC 2124: Controlling Microbes to Fight Infection, University of Tübingen, 72076 Tübingen, Germany.,German Center for Infection Research, Partner Site Tübingen, 72076 Tübingen, Germany
| | - Heike Brötz-Oesterhelt
- Department of Microbial Bioactive Compounds, Interfaculty Institute for Microbiology and Infection Medicine, University of Tübingen, 72076 Tübingen, Germany.,Cluster of Excellence EXC 2124: Controlling Microbes to Fight Infection, University of Tübingen, 72076 Tübingen, Germany.,German Center for Infection Research, Partner Site Tübingen, 72076 Tübingen, Germany
| | - Robin Teufel
- Pharmaceutical Biology, Department of Pharmaceutical Sciences, Klingelbergstrasse 50, University of Basel, 4056 Basel, Switzerland
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4
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Sawale M, Ozadali F, Valentine CJ, Benyathiar P, Drolia R, Mishra DK. Impact of bovine lactoferrin fortification on pathogenic organisms to attenuate the risk of infection for infants. Food Control 2022. [DOI: 10.1016/j.foodcont.2022.109078] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
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5
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Effect of methylpyrazoles and coumarin association on the growth of Gram-negative bacteria. Arch Microbiol 2022; 204:160. [PMID: 35113268 DOI: 10.1007/s00203-022-02773-5] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2021] [Revised: 01/09/2022] [Accepted: 01/18/2022] [Indexed: 11/02/2022]
Abstract
One approach to overcome the antimicrobial resistance of many pathogens is to associate compounds with antimicrobial properties and obtain combinations superior compared to the effect of each compound. To identify a possible potentiating effect, we tested and analyzed the inhibitory effect of the combination of coumarin with two pyrazole derivatives, 1,1'-methandiylbis (3,5-dimethyl-1H-pyrazole (AM4) and 3,5-dimethyl-1H-pyrazol-1-yl) methanol 3,5-dimethyl-1-hydroxymethylpyrazol (SAM4). A clear synergistic effect was recorded when coumarin was associated with SAM4, in which case the Fractional Inhibitory Concentration Index (FICI) had a value equal to 0.468 for Citrobacter freundii, Proteus mirabilis, and E. coli. In the other cases, however, both the association between coumarin and AM4 and coumarin SAM4 had only an additive effect (FICI = 0.937-1.00). The bactericidal effect of the coumarin-pyrazole combination over time was better in all cases compared to the effect of the compounds used separately. The viability of the bacterial cells at sub-inhibitory concentrations of the tested compounds was variable, depending on both the type of compound and the bacterial strain.
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6
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Jesus C, Soares R, Cunha E, Grilo M, Tavares L, Oliveira M. Influence of Nisin-Biogel at Subinhibitory Concentrations on Virulence Expression in Staphylococcus aureus Isolates from Diabetic Foot Infections. Antibiotics (Basel) 2021; 10:antibiotics10121501. [PMID: 34943712 PMCID: PMC8698857 DOI: 10.3390/antibiotics10121501] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2021] [Revised: 12/02/2021] [Accepted: 12/03/2021] [Indexed: 01/22/2023] Open
Abstract
A new approach to diabetic foot infections (DFIs) has been investigated, using a nisin-biogel combining the antimicrobial peptide (AMP) nisin with the natural polysaccharide guar-gum. Since in in vivo conditions bacteria may be exposed to decreased antimicrobial concentrations, known as subinhibitory concentrations (sub-MICs), effects of nisin-biogel sub-MIC values corresponding to 1/2, 1/4 and 1/8 of nisin's minimum inhibitory concentration (MIC) on virulence expression by six Staphylococcus aureus DFI isolates was evaluated by determining bacteria growth rate; expression of genes encoding for staphylococcal protein A (spA), coagulase (coa), clumping factor A (clfA), autolysin (atl), intracellular adhesin A (icaA), intracellular adhesin D (icaD), and the accessory gene regulator I (agrI); biofilm formation; Coa production; and SpA release. Nisin-biogel sub-MICs decreased bacterial growth in a strain- and dose-dependent manner, decreased agrI, atl and clfA expression, and increased spA, coa, icaA and icaD expression. Biofilm formation increased in the presence of nisin-biogel at 1/4 and 1/8 MIC, whereas 1/2 MIC had no effect. Finally, nisin-biogel at sub-MICs did not affect coagulase production, but decreased SpA production in a dose-dependent manner. Results highlight the importance of optimizing nisin-biogel doses before proceeding to in vivo trials, to reduce the risk of virulence factor's up-regulation due to the presence of inappropriate antimicrobial concentrations.
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Mojsoska B, Ghoul M, Perron GG, Jenssen H, Alatraktchi FA. Changes in toxin production of environmental Pseudomonas aeruginosa isolates exposed to sub-inhibitory concentrations of three common antibiotics. PLoS One 2021; 16:e0248014. [PMID: 33662048 PMCID: PMC7932067 DOI: 10.1371/journal.pone.0248014] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2020] [Accepted: 02/17/2021] [Indexed: 12/02/2022] Open
Abstract
Pseudomonas aeruginosa is an environmental pathogen that can cause severe infections in immunocompromised patients. P. aeruginosa infections are typically treated with multiple antibiotics including tobramycin, ciprofloxacin, and meropenem. However, antibiotics do not always entirely clear the bacteria from the infection site, where they may remain virulent. This is because the effective antibiotic concentration and diffusion in vitro may differ from the in vivo environment in patients. Therefore, it is important to understand the effect of non-lethal sub-inhibitory antibiotic concentrations on bacterial phenotype. Here, we investigate if sub-inhibitory antimicrobial concentrations cause alterations in bacterial virulence factor production using pyocyanin as a model toxin. We tested this using the aforementioned antibiotics on 10 environmental P. aeruginosa strains. Using on-the-spot electrochemical screening, we were able to directly quantify changes in production of pyocyanin in a measurement time of 17 seconds. Upon selecting 3 representative strains to further test the effects of sub-minimum inhibitory concentration (MICs), we found that pyocyanin production changed significantly when the bacteria were exposed to 10-fold MIC of the 3 antibiotics tested, and this was strain specific. A series of biologically relevant measured pyocyanin concentrations were also used to assess the effects of increased virulence on a culture of epithelial cells. We found a decreased viability of the epithelial cells when incubated with biologically relevant pyocyanin concentrations. This suggests that the antibiotic-induced virulence also is a value worth being enclosed in regular testing of pathogens.
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Affiliation(s)
- Biljana Mojsoska
- Department of Science and Environment, Roskilde University, Roskilde, Denmark
- PreDiagnose, Karlslunde, Denmark
| | - Melanie Ghoul
- Department of Zoology, University of Oxford, Oxford, United Kingdom
| | - Gabriel G. Perron
- Department of Biology, Bard College, Annandale-On-Hudson, NY, United States of America
| | - Håvard Jenssen
- Department of Science and Environment, Roskilde University, Roskilde, Denmark
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Sawada T, Katayama M, Takatani S, Ohiro Y. Early detection of drug-resistant Streptococcus pneumoniae and Haemophilus influenzae by quantitative flow cytometry. Sci Rep 2021; 11:2873. [PMID: 33536509 PMCID: PMC7859230 DOI: 10.1038/s41598-021-82186-4] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2020] [Accepted: 01/04/2021] [Indexed: 01/30/2023] Open
Abstract
Early detection of drug resistance contributes to combating drug-resistant bacteria and improving patient outcomes. Microbial testing in the laboratory is essential for treating infectious diseases because it can provide critical information related to identifying pathogenic bacteria and their resistance profiles. Despite these clinical requirements, conventional phenotypic testing is time-consuming. Additionally, recent rapid drug resistance tests are not compatible with fastidious bacteria such as Streptococcus and Haemophilus species. In this study, we validated the feasibility of direct bacteria counting using highly sensitive quantitative flow cytometry. Furthermore, by combining flow cytometry and a nucleic acid intercalator, we constructed a highly sensitive method for counting viable fastidious bacteria. These are inherently difficult to measure due to interfering substances from nutrients contained in the medium. Based on the conventional broth microdilution method, our method acquired a few microliter samples in a time series from the same microplate well to exclude the growth curve inconsistency between the samples. Fluorescent staining and flow cytometry measurements were completed within 10 min. Therefore, this approach enabled us to determine antimicrobial resistance for these bacteria within a few hours. Highly sensitive quantitative flow cytometry presents a novel avenue for conducting rapid antimicrobial susceptibility tests.
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Affiliation(s)
- Takahiro Sawada
- grid.508063.80000 0004 1771 0244Fundamental Research Laboratory, Research and Development Division, Eiken Chemical Co., Ltd., 143 Nogi, Nogimachi, Shimotsuga-gun, Tochigi, 329-0114 Japan
| | - Masayuki Katayama
- grid.419812.70000 0004 1777 4627FCM Development, Business Strategy Development, Sysmex Corporation, 4-4-4 Takatsukadai, Nishi-ku, Kobe, 651-2271 Japan
| | - Shogo Takatani
- grid.419812.70000 0004 1777 4627FCM Development, Business Strategy Development, Sysmex Corporation, 4-4-4 Takatsukadai, Nishi-ku, Kobe, 651-2271 Japan
| | - Yoshiyuki Ohiro
- grid.508063.80000 0004 1771 0244Fundamental Research Laboratory, Research and Development Division, Eiken Chemical Co., Ltd., 143 Nogi, Nogimachi, Shimotsuga-gun, Tochigi, 329-0114 Japan
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Stull-Lane AR, Lokken-Toyli KL, Diaz-Ochoa VE, Walker GT, Cevallos SA, Winter ALN, Muñoz ADH, Yang GG, Velazquez EM, Wu CY, Tsolis RM. Vitamin A supplementation boosts control of antibiotic-resistant Salmonella infection in malnourished mice. PLoS Negl Trop Dis 2020; 14:e0008737. [PMID: 33006970 PMCID: PMC7556496 DOI: 10.1371/journal.pntd.0008737] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2020] [Revised: 10/14/2020] [Accepted: 08/20/2020] [Indexed: 01/03/2023] Open
Abstract
Disseminated disease from non-typhoidal Salmonella enterica strains results in >20% mortality globally. Barriers to effective treatment include emerging multidrug resistance, antibiotic treatment failure, and risk factors such as malnutrition and related micronutrient deficiencies. Individuals in sub-Saharan Africa are disproportionately affected by non-typhoidal S. enterica bloodstream infections. To inform a clinical trial in people, we investigated vitamin A as a treatment in the context of antibiotic treatment failure in a mouse model of vitamin A deficiency. Vitamin A-deficient (VAD) mice exhibited higher systemic bacterial levels with a multidrug-resistant clinical isolate in comparison to mice on a control diet. Sex-specific differences in vitamin A deficiency and disseminated infection with S. enterica serotype Typhimurium (S. Typhimurium) were observed. VAD male mice had decreased weight gain compared to control male mice. Further, infected VAD male mice had significant weight loss and decreased survival during the course of infection. These differences were not apparent in female mice. In a model of disseminated S. Typhimurium infection and antibiotic treatment failure, we assessed the potential of two consecutive doses of vitamin A in alleviating infection in male and female mice on a VAD or control diet. We found that subtherapeutic antibiotic treatment synergized with vitamin A treatment in infected VAD male mice, significantly decreasing systemic bacterial levels, mitigating weight loss and improving survival. These results suggest that assessing vitamin A as a therapy during bacteremia in malnourished patients may lead to improved health outcomes in a subset of patients, especially in the context of antibiotic treatment failure. Non-typhoidal Salmonella serotypes generally cause diarrhea in people. However, there are certain factors that make people at risk of developing a more severe infection where the bacteria can enter the blood and cause fever and whole-body symptoms. Patients with this infection are usually hospitalized, and about one in five patients do not survive. The factors that make this bloodstream infection possible include pathogen features like resistance to antibiotics and patient factors like a malnourished state. Better treatments are needed. In this study, the authors assess vitamin A as a treatment during antibiotic treatment failure in a mouse model. Vitamin A-deficient male mice have better outcomes with vitamin A and antibiotic co-therapy, whereas female mice do not benefit. Despite similar levels of bacteria causing infection systemically, female mice show better outcomes in terms of weight loss and survival than male mice overall. This research provides evidence that a clinical study assessing vitamin A as a treatment in people could lead to improved survival for malnourished patients presenting with severe bloodstream infection.
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Affiliation(s)
- Annica R. Stull-Lane
- Department of Microbiology & Immunology, School of Medicine, University of California Davis, Davis, California, United States of America
| | - Kristen L. Lokken-Toyli
- Department of Microbiology & Immunology, School of Medicine, University of California Davis, Davis, California, United States of America
- Department of Microbiology, New York University, New York, New York, United States of America
| | - Vladimir E. Diaz-Ochoa
- Department of Microbiology & Immunology, School of Medicine, University of California Davis, Davis, California, United States of America
| | - Gregory T. Walker
- Department of Microbiology & Immunology, School of Medicine, University of California Davis, Davis, California, United States of America
| | - Stephanie A. Cevallos
- Department of Microbiology & Immunology, School of Medicine, University of California Davis, Davis, California, United States of America
| | - Andromeda L. N. Winter
- Department of Microbiology & Immunology, School of Medicine, University of California Davis, Davis, California, United States of America
| | - Ariel Del Hoyo Muñoz
- Department of Microbiology & Immunology, School of Medicine, University of California Davis, Davis, California, United States of America
| | - Guiyan G. Yang
- Department of Microbiology & Immunology, School of Medicine, University of California Davis, Davis, California, United States of America
- Department of Veterinary Clinical Sciences, College of Veterinary Medicine, China Agricultural University, Beijing, China
| | - Eric M. Velazquez
- Department of Microbiology & Immunology, School of Medicine, University of California Davis, Davis, California, United States of America
| | - Chun-Yi Wu
- Department of Neurology, School of Medicine, University of California, Davis, Sacramento, California, United States of America
| | - Renée M. Tsolis
- Department of Microbiology & Immunology, School of Medicine, University of California Davis, Davis, California, United States of America
- * E-mail:
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Ching C, Orubu ESF, Sutradhar I, Wirtz VJ, Boucher HW, Zaman MH. Bacterial antibiotic resistance development and mutagenesis following exposure to subinhibitory concentrations of fluoroquinolones in vitro: a systematic review of the literature. JAC Antimicrob Resist 2020; 2:dlaa068. [PMID: 34223024 PMCID: PMC8210091 DOI: 10.1093/jacamr/dlaa068] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2020] [Accepted: 07/15/2020] [Indexed: 12/09/2022] Open
Abstract
BACKGROUND Understanding social and scientific drivers of antibiotic resistance is critical to help preserve antibiotic efficacy. These drivers include exposure to subinhibitory antibiotic concentrations in the environment and clinic. OBJECTIVES To summarize and quantify the relationship between subinhibitory fluoroquinolone exposure and antibiotic resistance and mutagenesis to better understand resistance patterns and mechanisms. METHODS Following PRISMA guidelines, PubMed, Web of Science and Embase were searched for primary in vitro experimental studies on subinhibitory fluoroquinolone exposure and bacterial antibiotic resistance and mutagenesis, from earliest available dates through to 2018 without language limitation. A specifically developed non-weighted tool was used to assess risk of bias. RESULTS Evidence from 62 eligible studies showed that subinhibitory fluoroquinolone exposure results in increased resistance to the selecting fluoroquinolone. Most increases in MIC were low (median minimum of 3.7-fold and median maximum of 32-fold) and may not be considered clinically relevant. Mechanistically, resistance is partly explained by target mutations but also changes in drug efflux. Collaterally, resistance to other fluoroquinolones and unrelated antibiotic classes also develops. The mean ± SD quality score for all studies was 2.6 ± 1.8 with a range of 0 (highest score) to 7 (lowest score). CONCLUSIONS Low and moderate levels of resistance and efflux changes can create an opportunity for higher-level resistance or MDR. Future studies, to elucidate the genetic regulation of specific resistance mechanisms, and increased policies, including surveillance of low-level resistance changes or genomic surveillance of efflux pump genes and regulators, could serve as a predictor of MDR development.
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Affiliation(s)
- Carly Ching
- Department of Biomedical Engineering, Boston University, Boston, MA, USA
| | - Ebiowei S F Orubu
- Department of Biomedical Engineering, Boston University, Boston, MA, USA
- Institute for Health System Innovation & Policy, Boston University, Boston, MA, USA
| | - Indorica Sutradhar
- Department of Biomedical Engineering, Boston University, Boston, MA, USA
| | - Veronika J Wirtz
- Department of Global Health, Boston University School of Public Health, Boston, MA, USA
| | - Helen W Boucher
- Division of Geographic Medicine and Infectious Diseases, Tufts Medical Center, Boston, MA, USA
| | - Muhammad H Zaman
- Department of Biomedical Engineering, Boston University, Boston, MA, USA
- Howard Hughes Medical Institute, Boston University, Boston, MA, USA
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Adamus-Białek W, Wawszczak M, Arabski M, Majchrzak M, Gulba M, Jarych D, Parniewski P, Głuszek S. Ciprofloxacin, amoxicillin, and aminoglycosides stimulate genetic and phenotypic changes in uropathogenic Escherichia coli strains. Virulence 2020; 10:260-276. [PMID: 30938219 PMCID: PMC6527016 DOI: 10.1080/21505594.2019.1596507] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Antibiotic therapy and its consequences in bacterial and human aspects are widely investigated. Despite this, the emergence of new multidrug resistant bacteria is still a current problem. The scope of our work included the observation of changes among uropathogenic Escherichia coli strains after the treatment with a subinhibitory concentration of different antibiotics. The sensitive strains with or without virulence factors were incubated with amoxicillin, ciprofloxacin, gentamycin, or tobramycin. After each passage, the E. coli derivatives were compared to their wild types based on their susceptibility profiles, virulence genes, biofilm formations and the fingerprint profiles of PCR products amplified with using the (N)(6)(CGG)(4) primer. It turned out that antibiotics caused significant changes in the repertoire of bacterial virulence and biofilm formation, corresponding to acquired cross-resistance. The genomic changes among the studied bacteria were reflected in the changed profiles of the CGG-PCR products. In conclusion, the inappropriate application of antibiotics may cause a rapid rise of Multidrug Resistant (MDR) strains and give bacteria a chance to modulate their own pathogenicity. This phenomenon has been easily observed among uropathogenic E. coli strains and it is one of the main reasons for recurrent infections of the urinary tract.
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Affiliation(s)
- Wioletta Adamus-Białek
- a Department of Surgery and Surgical Nursery with Laboratory of Genetics, Faculty of Medicine and Health Sciences , Jan Kochanowski University , Kielce , Poland
| | - Monika Wawszczak
- a Department of Surgery and Surgical Nursery with Laboratory of Genetics, Faculty of Medicine and Health Sciences , Jan Kochanowski University , Kielce , Poland
| | - Michał Arabski
- b Department of Biochemistry & Genetics , Jan Kochanowski University , Kielce , Poland
| | - Michał Majchrzak
- a Department of Surgery and Surgical Nursery with Laboratory of Genetics, Faculty of Medicine and Health Sciences , Jan Kochanowski University , Kielce , Poland
| | - Martyna Gulba
- a Department of Surgery and Surgical Nursery with Laboratory of Genetics, Faculty of Medicine and Health Sciences , Jan Kochanowski University , Kielce , Poland
| | - Dariusz Jarych
- c Institute of Medical Biology, Polish Academy of Sciences , Łódź , Poland
| | - Paweł Parniewski
- c Institute of Medical Biology, Polish Academy of Sciences , Łódź , Poland
| | - Stanisław Głuszek
- a Department of Surgery and Surgical Nursery with Laboratory of Genetics, Faculty of Medicine and Health Sciences , Jan Kochanowski University , Kielce , Poland
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Massai F, Saleeb M, Doruk T, Elofsson M, Forsberg Å. Development, Optimization, and Validation of a High Throughput Screening Assay for Identification of Tat and Type II Secretion Inhibitors of Pseudomonas aeruginosa. Front Cell Infect Microbiol 2019; 9:250. [PMID: 31355152 PMCID: PMC6635566 DOI: 10.3389/fcimb.2019.00250] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2019] [Accepted: 06/26/2019] [Indexed: 11/13/2022] Open
Abstract
Antibiotics are becoming less effective in treatment of infections caused by multidrug-resistant Pseudomonas aeruginosa. Antimicrobial therapies based on the inhibition of specific virulence-related traits, as opposed to growth inhibitors, constitute an innovative and appealing approach to tackle the threat of P. aeruginosa infections. The twin-arginine translocation (Tat) pathway plays an important role in the pathogenesis of P. aeruginosa, and constitutes a promising target for the development of anti-pseudomonal drugs. In this study we developed and optimized a whole-cell, one-well assay, based on native phospholipase C activity, to identify compounds active against the Tat system. Statistical robustness, sensitivity and consequently suitability for high-throughput screening (HTS) were confirmed by a dry run/pre-screening test scoring a Z′ of 0.82 and a signal-to-noise ratio of 49. Using this assay, we evaluated ca. 40,000 molecules and identified 59 initial hits as possible Tat inhibitors. Since phospholipase C is exported into the periplasm by Tat, and subsequently translocated across the outer membrane by the type II secretion system (T2SS), our assay could also identify T2SS inhibitors. To validate our hits and discriminate between compounds that inhibited either Tat or T2SS, two separate counter assays were developed and optimized. Finally, three Tat inhibitors and one T2SS inhibitor were confirmed by means of dose-response analysis and additional counter and confirming assays. Although none of the identified inhibitors was suitable as a lead compound for drug development, this study validates our assay as a simple, efficient, and HTS compatible method for the identification of Tat and T2SS inhibitors.
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Affiliation(s)
- Francesco Massai
- Laboratory for Molecular Infection Medicine Sweden, Department of Molecular Biology, Umeå University, Umeå, Sweden.,Department of Molecular Biology, Umeå Centre for Microbial Research, Umeå University, Umeå, Sweden
| | - Michael Saleeb
- Department of Chemistry, Umeå Centre for Microbial Research, Umeå University, Umeå, Sweden
| | - Tugrul Doruk
- Laboratory for Molecular Infection Medicine Sweden, Department of Molecular Biology, Umeå University, Umeå, Sweden.,Department of Molecular Biology, Umeå Centre for Microbial Research, Umeå University, Umeå, Sweden
| | - Mikael Elofsson
- Department of Chemistry, Umeå Centre for Microbial Research, Umeå University, Umeå, Sweden
| | - Åke Forsberg
- Laboratory for Molecular Infection Medicine Sweden, Department of Molecular Biology, Umeå University, Umeå, Sweden.,Department of Molecular Biology, Umeå Centre for Microbial Research, Umeå University, Umeå, Sweden
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Postantibiotic and Sub-MIC Effects of Exebacase (Lysin CF-301) Enhance Antimicrobial Activity against Staphylococcus aureus. Antimicrob Agents Chemother 2019; 63:AAC.02616-18. [PMID: 30936103 DOI: 10.1128/aac.02616-18] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2018] [Accepted: 03/24/2019] [Indexed: 12/13/2022] Open
Abstract
CF-301 (exebacase) is a recombinantly produced bacteriophage-derived lysin (cell wall hydrolase) and is the first agent of this class to enter clinical development in the United States for treating bacteremia including endocarditis due to Staphylococcus aureus Whereas rapid bactericidal activity is the hallmark in vitro and in vivo response to CF-301 at exposures higher than the MIC, prolonged antimicrobial activity, mediated by cell wall damage, is predicted at concentrations less than the MIC. In the current study, a series of in vitro pharmacodynamic parameters, including the postantibiotic effect (PAE), postantibiotic sub-MIC effect (PA-SME), and sub-MIC effect (SME), were studied to determine how short-duration and sub-MIC CF-301 exposures affect the growth of surviving staphylococci and extend its antimicrobial activity. Mean PAE, PA-SME, and SME values up to 4.8, 9.3, and 9.8 h, respectively, were observed against 14 staphylococcal strains tested in human serum; growth delays were extended by 6 h in the presence of daptomycin. Exposures to CF-301 at sub-MIC levels as low as 0.001× to 0.01× MIC (∼1 to 10 ng/ml) resulted in aberrant cell wall ultrastructure, increased membrane permeability, dissipation of membrane potential, and inhibition of virulence phenotypes, including agglutination and biofilm formation. A mouse thigh infection model designed to study the PAE was used to confirm our findings and demonstrate in vivo growth delays of ≥19.3 h. Our findings suggest that at CF-301 concentrations less than the MIC during therapeutic use, sustained reductions in bacterial fitness and virulence may substantially enhance efficacy.
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Mao Y, Hoffman T, Singh-Varma A, Duan-Arnold Y, Moorman M, Danilkovitch A, Kohn J. Antimicrobial Peptides Secreted From Human Cryopreserved Viable Amniotic Membrane Contribute to its Antibacterial Activity. Sci Rep 2017; 7:13722. [PMID: 29057887 PMCID: PMC5651856 DOI: 10.1038/s41598-017-13310-6] [Citation(s) in RCA: 42] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2017] [Accepted: 09/21/2017] [Indexed: 12/18/2022] Open
Abstract
Chronic wounds remain a large problem in the field of medicine and are often associated with risk of infection and amputation. Recently, a commercially available human cryopreserved viable amniotic membrane (hCVAM) has been shown to effectively promote wound closure and reduce wound-related infections. A sprevious study indicates that hCVAM can inhibit the growth of bacteria associated with chronic wounds. In the present study, we investigated the mechanism of hCVAM antimicrobial activity. Our data demonstrate that antimicrobial activities against common pathogens in chronic wounds such as P.aeruginosa, S.aureus and Methicillin-resistant S.aureus (MRSA) are mediated via the secretion of soluble factors by viable cells in hCVAM and that these factors are proteins in nature. Further, we show that genes for antimicrobial peptides (AMPs) including human beta-defensins (HBDs) are expressed by hCVAM and that expression levels positively correlate with antimicrobial activity of hCVAM. At the protein level, our data indicate that HBD2 and HBD3 are secreted by hCVAM and directly contribute to its activity against P. aeruginosa. These data provide evidence that soluble factors including AMPs are hCVAM antimicrobial agents and are consistent with a role for AMPs in mediating antimicrobial properties of the membrane.
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Affiliation(s)
- Yong Mao
- New Jersey Center for Biomaterials Rutgers University 145 Bevier Rd., Piscataway, NJ, 08854, United States
| | - Tyler Hoffman
- New Jersey Center for Biomaterials Rutgers University 145 Bevier Rd., Piscataway, NJ, 08854, United States
| | - Anya Singh-Varma
- New Jersey Center for Biomaterials Rutgers University 145 Bevier Rd., Piscataway, NJ, 08854, United States
| | - Yi Duan-Arnold
- Osiris Therapeutics, Inc, Columbia, MD, 21046, United States
| | - Matthew Moorman
- Osiris Therapeutics, Inc, Columbia, MD, 21046, United States
| | | | - Joachim Kohn
- New Jersey Center for Biomaterials Rutgers University 145 Bevier Rd., Piscataway, NJ, 08854, United States.
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15
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Maciejewska M, Adam D, Martinet L, Naômé A, Całusińska M, Delfosse P, Carnol M, Barton HA, Hayette MP, Smargiasso N, De Pauw E, Hanikenne M, Baurain D, Rigali S. A Phenotypic and Genotypic Analysis of the Antimicrobial Potential of Cultivable Streptomyces Isolated from Cave Moonmilk Deposits. Front Microbiol 2016; 7:1455. [PMID: 27708627 PMCID: PMC5030222 DOI: 10.3389/fmicb.2016.01455] [Citation(s) in RCA: 44] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2016] [Accepted: 08/31/2016] [Indexed: 12/21/2022] Open
Abstract
Moonmilk speleothems of limestone caves host a rich microbiome, among which Actinobacteria represent one of the most abundant phyla. Ancient medical texts reported that moonmilk had therapeutical properties, thereby suggesting that its filamentous endemic actinobacterial population might be a source of natural products useful in human treatment. In this work, a screening approach was undertaken in order to isolate cultivable Actinobacteria from moonmilk of the Grotte des Collemboles in Belgium, to evaluate their taxonomic profile, and to assess their potential in biosynthesis of antimicrobials. Phylogenetic analysis revealed that all 78 isolates were exclusively affiliated to the genus Streptomyces and clustered into 31 distinct phylotypes displaying various pigmentation patterns and morphological features. Phylotype representatives were tested for antibacterial and antifungal activities and their genomes were mined for secondary metabolite biosynthetic genes coding for non-ribosomal peptide synthetases (NRPSs), and polyketide synthases (PKS). The moonmilk Streptomyces collection was found to display strong inhibitory activities against a wide range of reference organisms, as 94, 71, and 94% of the isolates inhibited or impaired the growth of Gram-positive, Gram-negative bacteria, and fungi, respectively. Interestingly, 90% of the cave strains induced strong growth suppression against the multi-drug resistant Rasamsonia argillacea, a causative agent of invasive mycosis in cystic fibrosis and chronic granulomatous diseases. No correlation was observed between the global antimicrobial activity of an individual strain and the number of NRPS and PKS genes predicted in its genome, suggesting that approaches for awakening cryptic metabolites biosynthesis should be applied to isolates with no antimicrobial phenotype. Overall, our work supports the common belief that moonmilk might effectively treat various infectious diseases thanks to the presence of a highly diverse population of prolific antimicrobial producing Streptomyces, and thus may indeed constitute a promising reservoir of potentially novel active natural compounds.
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Affiliation(s)
- Marta Maciejewska
- InBioS - Centre for Protein Engineering, Institut de Chimie B6a, University of Liège Liège, Belgium
| | - Delphine Adam
- InBioS - Centre for Protein Engineering, Institut de Chimie B6a, University of Liège Liège, Belgium
| | - Loïc Martinet
- InBioS - Centre for Protein Engineering, Institut de Chimie B6a, University of Liège Liège, Belgium
| | - Aymeric Naômé
- InBioS - Centre for Protein Engineering, Institut de Chimie B6a, University of Liège Liège, Belgium
| | - Magdalena Całusińska
- Environmental Research and Innovation Department, Luxembourg Institute of Science and Technology Belvaux, Luxembourg
| | - Philippe Delfosse
- Environmental Research and Innovation Department, Luxembourg Institute of Science and Technology Belvaux, Luxembourg
| | - Monique Carnol
- InBioS - Plant and Microbial Ecology, Botany B22, University of Liège Liège, Belgium
| | - Hazel A Barton
- Department of Biology, University of Akron, Akron OH, USA
| | - Marie-Pierre Hayette
- Department of Clinical Microbiology, University Hospital of Liège Liège, Belgium
| | - Nicolas Smargiasso
- MolSys Research Unit, Mass Spectrometry Laboratory, University of Liège Liège, Belgium
| | - Edwin De Pauw
- MolSys Research Unit, Mass Spectrometry Laboratory, University of Liège Liège, Belgium
| | - Marc Hanikenne
- InBioS - Functional Genomics and Plant Molecular Imaging, University of LiègeLiège, Belgium; PhytoSYSTEMS, University of LiègeLiège, Belgium
| | - Denis Baurain
- PhytoSYSTEMS, University of LiègeLiège, Belgium; InBioS - Eukaryotic Phylogenomics, University of LiègeLiège, Belgium
| | - Sébastien Rigali
- InBioS - Centre for Protein Engineering, Institut de Chimie B6a, University of Liège Liège, Belgium
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16
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Noreddin AM, Haynes VL, Zhanel GG. Pharmacokinetics and Pharmacodynamics of the New Quinolones. J Pharm Pract 2016. [DOI: 10.1177/0897190005282397] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
In this review, the authors describe the pharmacokinetic (PK) and pharmacodynamic (PD) characteristics of the new quinolones (levofloxacin, gatifloxacin, moxifloxacin, gemifloxacin, and garenoxacin) and discuss their implications on adequate therapy of patients with respiratory infections. The newer quinolones display excellent bioavailability and have longer serum half-lives than ciprofloxacin. In addition, they have the ability to concentrate in respiratory tract tissues and fluids at levels that exceed serum-drug concentrations. Also, the newer quinolones exhibit broad-spectrum activity against both susceptible and resistant organisms. Those favorable PK/PD properties make the new quinolones an attractive therapeutic alternative to traditional agents for common respiratory infections. Understanding the PK/PD of quinolone antibiotics can facilitate selection of optimal regimens to hasten response, prevent treatment failures, and minimize the development of resistance.
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Affiliation(s)
- Ayman M. Noreddin
- College of Pharmacy, University of Minnesota, Duluth, MNDepartment of Pharmacy Practice and Pharmaceutical Sciences, College of Pharmacy, University of Minnesota, Duluth, Department of Medical Microbiology, University of Manitoba, Winnipeg, Manitoba, Canada
| | - Virginia L. Haynes
- Department of Pharmacy Practice and Pharmaceutical Sciences, College of Pharmacy, University of Minnesota, Duluth
| | - George G. Zhanel
- Department of Medical Microbiology at the University of Manitoba, Winnipeg, Manitoba, Canada
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17
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Discovery of novel cell wall-active compounds using P ywaC, a sensitive reporter of cell wall stress, in the model gram-positive bacterium Bacillus subtilis. Antimicrob Agents Chemother 2014; 58:3261-9. [PMID: 24687489 DOI: 10.1128/aac.02352-14] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The emergence of antibiotic resistance in recent years has radically reduced the clinical efficacy of many antibacterial treatments and now poses a significant threat to public health. One of the earliest studied well-validated targets for antimicrobial discovery is the bacterial cell wall. The essential nature of this pathway, its conservation among bacterial pathogens, and its absence in human biology have made cell wall synthesis an attractive pathway for new antibiotic drug discovery. Herein, we describe a highly sensitive screening methodology for identifying chemical agents that perturb cell wall synthesis, using the model of the Gram-positive bacterium Bacillus subtilis. We report on a cell-based pilot screen of 26,000 small molecules to look for cell wall-active chemicals in real time using an autonomous luminescence gene cluster driven by the promoter of ywaC, which encodes a guanosine tetra(penta)phosphate synthetase that is expressed under cell wall stress. The promoter-reporter system was generally much more sensitive than growth inhibition testing and responded almost exclusively to cell wall-active antibiotics. Follow-up testing of the compounds from the pilot screen with secondary assays to verify the mechanism of action led to the discovery of 9 novel cell wall-active compounds.
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18
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Cíftçíoglu N, Miller-Hjelle MA, Hjelle JT, Kajander EO. Inhibition of nanobacteria by antimicrobial drugs as measured by a modified microdilution method. Antimicrob Agents Chemother 2002; 46:2077-86. [PMID: 12069958 PMCID: PMC127303 DOI: 10.1128/aac.46.7.2077-2086.2002] [Citation(s) in RCA: 63] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Abstract
Compounds from 16 classes of antimicrobial drugs were tested for their abilities to inhibit the in vitro multiplication of nanobacteria (NB), a newly discovered infectious agent found in human kidney stones and kidney cyst fluids from patients with polycystic kidney disease (PKD). Because NB form surface calcifications at physiologic levels of calcium and phosphate, they have been hypothesized to mediate the formation of tissue calcifications. We describe a modified microdilution inhibitory test that accommodates the unique growth conditions and long multiplication times of NB. This modified microdilution method included inoculation of 96-well plates and determination of inhibition by periodic measurement of the absorbance for 14 days in cell culture medium under cell culture conditions. Bactericidal or bacteriostatic drug effects were distinguished by subsequent subculture in drug-free media and monitoring for increasing absorbance. NB isolated from fetal bovine serum (FBS) were inhibited by tetracycline HCl, nitrofurantoin, trimethoprim, trimethoprim-sulfamethoxazole, and ampicillin at levels achievable in serum and urine; all drugs except ampicillin were cidal. Tetracycline also inhibited multiplication of isolates of NB from human kidney stones and kidney cyst fluids from patients with PKD. The other antibiotics tested against FBS-derived NB either had no effect or exhibited an inhibitory concentration above clinically achievable levels; the aminoglycosides and vancomycin were bacteriostatic. Antibiotic-induced morphological changes to NB were observed by electron microscopy. Bisphosphonates, aminocaproic acid, potassium citrate-citric acid solutions, and 5-fluorouracil also inhibited the multiplication of NB in a cidal manner. Insights into the nature of NB, the action(s) of these drugs, and the role of NB in calcifying diseases may be gained by exploiting this in vitro inhibition test system.
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Affiliation(s)
- N Cíftçíoglu
- Department of Biochemistry, University of Kuopio, FIN-70211, Kuopio, Finland
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Zhanel GG, Ennis K, Vercaigne L, Walkty A, Gin AS, Embil J, Smith H, Hoban DJ. A critical review of the fluoroquinolones: focus on respiratory infections. Drugs 2002; 62:13-59. [PMID: 11790155 DOI: 10.2165/00003495-200262010-00002] [Citation(s) in RCA: 269] [Impact Index Per Article: 12.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
The new fluoroquinolones (clinafloxacin, gatifloxacin, gemifloxacin, grepafloxacin, levofloxacin, moxifloxacin, sitafloxacin, sparfloxacin and trovafloxacin) offer excellent activity against Gram-negative bacilli and improved Gram-positive activity (e.g. against Streptococcus pneumoniae and Staphylococcus aureus) over ciprofloxacin. Ciprofloxacin still maintains the best in vitro activity against Pseudomonas aeruginosa. Clinafloxacin, gatifloxacin, moxifloxacin, sitafloxacin, sparfloxacin and trovafloxacin display improved activity against anaerobes (e.g. Bacteroides fragilis) versus ciprofloxacin. All of the new fluoroquinolones display excellent bioavailability and have longer serum half-lives than ciprofloxacin allowing for once daily dose administration. Clinical trials comparing the new fluoroquinolones to each other or to standard therapy have demonstrated good efficacy in a variety of community-acquired respiratory infections (e.g. pneumonia, acute exacerbations of chronic bronchitis and acute sinusitis). Limited data suggest that the new fluoroquinolones as a class may lead to better outcomes in community-acquired pneumonia and acute exacerbations of chronic bronchitis versus comparators. Several of these agents have either been withdrawn from the market, had their use severely restricted because of adverse effects (clinafloxacin because of phototoxicity and hypoglycaemia; grepafloxacin because of prolongation of the QTc and resultant torsades de pointes; sparfloxacin because of phototoxicity; and trovafloxacin because of hepatotoxicity), or were discontinued during developmental phases. The remaining fluoroquinolones such as gatifloxacin, gemifloxacin, levofloxacin and moxifloxacin have adverse effect profiles similar to ciprofloxacin. Extensive post-marketing safety surveillance data (as are available with ciprofloxacin and levofloxacin) are required for all new fluoroquinolones before safety can be definitively established. Drug interactions are limited; however, all fluoroquinolones interact with metal ion containing drugs (eg. antacids). The new fluoroquinolones (gatifloxacin, gemifloxacin, levofloxacin and moxifloxacin) offer several advantages over ciprofloxacin and are emerging as important therapeutic agents in the treatment of community-acquired respiratory infections. Their broad spectrum of activity which includes respiratory pathogens such as penicillin and macrolide resistant S. pneumoniae, favourable pharmacokinetic parameters, good bacteriological and clinical efficacy will lead to growing use of these agents in the treatment of community-acquired pneumonia, acute exacerbations of chronic bronchitis and acute sinusitis. These agents may result in cost savings especially in situations where, because of their potent broad-spectrum activity and excellent bioavailability, they may be used orally in place of intravenous antibacterials. Prudent use of the new fluoroquinolones will be required to minimise the development of resistance to these agents.
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Affiliation(s)
- George G Zhanel
- Department of Medical Microbiology, Faculty of Medicine, University of Manitoba, Winnipeg, Manitoba, Canada.
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Zhanel GG. Influence of Pharmacokinetic and Pharmacodynamic Principles on Antibiotic Selection. Curr Infect Dis Rep 2001; 3:29-34. [PMID: 11177728 DOI: 10.1007/s11908-001-0056-x] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
When evaluating the efficacy of antibiotics for the treatment of respiratory tract infections, such as community acquired pneumonia and acute exacerbations of chronic bronchitis, assessment of clinical cure may not be the most relevant parameter, as it may not be related to microbiological eradication or to the minimum inhibitory concentration (MIC) of the infecting pathogen. It is more relevant to study the efficacy of the antibiotic in eradicating the bacterial pathogen, because this is frequently related to both the MIC of the pathogen and the antibiotic dosage regimen. Pharmacodynamics correlates the concentration of antibiotic in the blood or at the infection site with its biological effect against the organism (bacteriological eradication). For beta-lactams, the pharmacodynamic parameter that best correlates with eradication is time (T) above MIC (T > MIC); for aminoglycosides and fluoroquinolones, it is the area under the curve at 24 hours (AUC(24))-to-MIC ratio (AUC(24)/MIC). Knowledge of pharmacodynamics allows optimum use of antibiotics; in vitro models, animal models, and retrospective and prospective clinical trials have shown that the use of such knowledge optimizes bacteriological eradication and enhances patient outcome. In the future, pharmacodynamic studies will be used not only to assess optimal ways for antibiotics to eradicate resistant pathogens, but also to investigate the ability of antibiotics to prevent the development of resistance on therapy and to eradicate pathogens from colonizing sites.
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Affiliation(s)
- George G. Zhanel
- Faculties of Medicine and Pharmacy, University of Manitoba; Departments of Medicine and Microbiology, Health Sciences Centre, 820 Sherbrook Street, Room MS673, Winnipeg, Manitoba R3A 1R9 Canada.
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Nichterlein T, Domann E, Kretschmar M, Bauer M, Hlawatsch A, Hof H, Chakraborty T. Subinhibitory concentrations of β-lactams and other cell-wall antibiotics inhibit listeriolysin production by Listeria monocytogenes. Int J Antimicrob Agents 1996; 7:75-81. [DOI: 10.1016/0924-8579(96)00014-3] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/07/1996] [Indexed: 10/17/2022]
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Zhanel GG. Changing strategies in aminoglycoside dosing; the result of research on antimicrobial pharmacodynamics. ZENTRALBLATT FUR BAKTERIOLOGIE : INTERNATIONAL JOURNAL OF MEDICAL MICROBIOLOGY 1993; 279:447-9. [PMID: 8305801 DOI: 10.1016/s0934-8840(11)80415-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Affiliation(s)
- G G Zhanel
- Faculty of Pharmacy, University of Manitoba, Winnipeg, Canada
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