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The History of Methicillin-Resistant Staphylococcus aureus in Brazil. ACTA ACUST UNITED AC 2020; 2020:1721936. [PMID: 33082892 PMCID: PMC7563066 DOI: 10.1155/2020/1721936] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2020] [Revised: 07/21/2020] [Accepted: 09/24/2020] [Indexed: 12/20/2022]
Abstract
Since the emergence of MRSA in the 1960s, a gradual increase in infections by resistant bacteria has been observed. Clinical manifestations may vary from brand to critical condition due to host risk factors, as well as pathogen virulence and resistance. The high adaptability and pathogenic profile of MRSA clones contributed to its spread in hospital and community settings. In Brazil, the first MRSA isolates were reported in the late 1980s, and since then different genetic profiles, such as the Brazilian epidemic clone (BEC) and other clones considered a pandemic, became endemic in the Brazilian population. Additionally, Brazil's MRSA clones were shown to be able to transfer genes involved in multidrug resistance and enhanced pathogenic properties. These events contributed to the rise of highly resistant and pathogenic MRSA. In this review, we present the main events which compose the history of MRSA in Brazil, including numbers and locations of isolation, as well as types of staphylococcal cassette chromosome mec (SCCmec) found in the Brazilian territory.
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Kong J, Wu ZX, Wei L, Chen ZS, Yoganathan S. Exploration of Antibiotic Activity of Aminoglycosides, in Particular Ribostamycin Alone and in Combination With Ethylenediaminetetraacetic Acid Against Pathogenic Bacteria. Front Microbiol 2020; 11:1718. [PMID: 32849365 PMCID: PMC7403490 DOI: 10.3389/fmicb.2020.01718] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2020] [Accepted: 06/30/2020] [Indexed: 11/16/2022] Open
Abstract
The emergence of infections caused by bacterial pathogens that are resistant to current antibiotic therapy is a critical healthcare challenge. Aminoglycosides are natural antibiotics with broad spectrum of activity; however, their clinical use is limited due to considerable nephrotoxicity. Moreover, drug-resistant bacteria that cause infections in human as well as livestock are less responsive to conventional antibiotics. Herein, we report the in vitro antibacterial evaluation of five different aminoglycosides, including ribostamycin, against a panel of Gram-positive and Gram-negative pathogens. Eight of the tested bacterial strains are linked to gastrointestinal (GI) infections. The minimum inhibitory concentration (MIC) of ribostamycin against three different Escherichia coli strains is in the range of 0.9–7.2 μM and against a strain of Haemophilus influenzae is 0.5 μM. We also found that the MIC of ribostamycin was considerably enhanced from 57.2 to 7.2 μM, an 8-fold improvement, when bacteria were treated with a combination of ribostamycin and ethylenediaminetetraacetic acid (EDTA). These findings demonstrate a promising approach to enhance the clinical potential of ribostamycin and provide a rational for its antibiotic reclassification from special level to non-restricted level.
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Affiliation(s)
- Jing Kong
- Department of Pharmaceutical Sciences, College of Pharmacy and Health Sciences, St. John's University, New York, NY, United States
| | - Zhuo-Xun Wu
- Department of Pharmaceutical Sciences, College of Pharmacy and Health Sciences, St. John's University, New York, NY, United States
| | - Liuya Wei
- Department of Pharmaceutical Sciences, College of Pharmacy and Health Sciences, St. John's University, New York, NY, United States.,School of Pharmacy, Weifang Medical University, Weifang, China
| | - Zhe-Sheng Chen
- Department of Pharmaceutical Sciences, College of Pharmacy and Health Sciences, St. John's University, New York, NY, United States
| | - Sabesan Yoganathan
- Department of Pharmaceutical Sciences, College of Pharmacy and Health Sciences, St. John's University, New York, NY, United States
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Wandiyanto JV, Cheeseman S, Truong VK, Kobaisi MA, Bizet C, Juodkazis S, Thissen H, Crawford RJ, Ivanova EP. Outsmarting superbugs: bactericidal activity of nanostructured titanium surfaces against methicillin- and gentamicin-resistantStaphylococcus aureusATCC 33592. J Mater Chem B 2019. [DOI: 10.1039/c9tb00102f] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
The colonisation of biomaterial surfaces by pathogenic bacteria is a significant issue of concern, particularly in light of the rapid rise of antibiotic resistance.
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Affiliation(s)
- Jason V. Wandiyanto
- School of Science
- Faculty of Science
- Engineering and Technology
- Swinburne University of Technology
- Hawthorn 3122 VIC
| | - Samuel Cheeseman
- School of Science
- College of Science
- Engineering and Health
- RMIT University
- Melbourne 3000 VIC
| | - Vi Khanh Truong
- School of Science
- College of Science
- Engineering and Health
- RMIT University
- Melbourne 3000 VIC
| | - Mohammad Al Kobaisi
- School of Science
- Faculty of Science
- Engineering and Technology
- Swinburne University of Technology
- Hawthorn 3122 VIC
| | | | - Saulius Juodkazis
- Centre for Micro-Photonics
- Faculty of Science
- Engineering and Technology
- Swinburne University of Technology
- Hawthorn 3122 VIC
| | | | - Russell J. Crawford
- School of Science
- College of Science
- Engineering and Health
- RMIT University
- Melbourne 3000 VIC
| | - Elena P. Ivanova
- School of Science
- College of Science
- Engineering and Health
- RMIT University
- Melbourne 3000 VIC
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Ferreira FS, Brito SV, Coutinho HDM, Souza EP, Almeida WO, Alves RRN. Vertebrates as a Bactericidal Agent. ECOHEALTH 2018; 15:619-626. [PMID: 29922961 DOI: 10.1007/s10393-018-1345-2] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/11/2016] [Revised: 05/15/2018] [Accepted: 05/16/2018] [Indexed: 06/08/2023]
Abstract
In Brazil, although a large number of animals are used in traditional medicine (at least 354 species), information about their biological activities is scarce. In this context, the objective of this study was to evaluate the bactericidal potential of zootherapeutic by-products from animals used in Brazilian traditional medicine and discuss the ecological and cultural consequences of such practices. The species analyzed were: Tupinambis merianae (skin), Iguana iguana (skin and body fat), Crotalus durissus (skin and body fat), Boa constrictor (skin), Euphractus sexcinctus (body fat) and Coendou prehensilis (quills). Experiments were performed with standard clinical strains of Escherichia coli (EC-ATCC10536) and Staphylococcus aureus (SA-ATCC 25923). For the microbiological assay, the zootherapeutics were evaluated using serial microdilutions. The results indicate that none of the samples possess inhibitory activity against standard bacterial strains. The in vitro ineffectiveness of the analyzed products demonstrate a necessity for new pharmacological research that encompass a large number of species of medicinal animals as well as highlight the importance of zootherapy in the context of plans for animal conservation.
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Affiliation(s)
- F S Ferreira
- Universidade Federal do Vale do São Francisco, Colegiado Acadêmico de Ecologia, Senhor do Bonfim, BA, Brazil.
| | - S V Brito
- Universidade Federal do Maranhão, Centro de Ciências Agrárias e Ambientais, Chapadinha, MA, Brazil
| | - H D M Coutinho
- Departamento de Química Biológica, Universidade Regional do Cariri, Crato, CE, Brazil
| | - E P Souza
- Departamento de Morfologia, Universidade Federal do Ceará, Fortaleza, CE, Brazil
| | - W O Almeida
- Departamento de Química Biológica, Universidade Regional do Cariri, Crato, CE, Brazil
| | - R R N Alves
- Departamento de Biologia, Universidade Estadual da Paraíba, Campina Grande, PB, Brazil
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Eldirdiri S, Lee J, Jack A, Wright A, Findlay A, Phillips G. Outbreak of gentamicin-resistant, meticillin-susceptible Staphlococcus aureus on a neonatal unit. J Hosp Infect 2018; 98:419-424. [DOI: 10.1016/j.jhin.2017.11.006] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2017] [Accepted: 11/13/2017] [Indexed: 11/15/2022]
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Panthee S, Hamamoto H, Paudel A, Sekimizu K. Genomic analysis of vancomycin-resistant Staphylococcus aureus VRS3b and its comparison with other VRSA isolates. Drug Discov Ther 2017; 11:78-83. [PMID: 28458299 DOI: 10.5582/ddt.2017.01024] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
High-level vancomycin resistance among Staphylococcus aureus poses a grave threat to global health as the treatment options for this pathogen are very limited. A detailed evaluation of the genetic background of vancomycin-resistant S. aureus (VRSA) is expected to facilitate the understanding of its origin and pathogenicity. In this study, we performed the genetic analysis of the clinical VRSA isolates and identified the genetic basis of resistance to multiple antibiotics among these strains, based on the available draft genome sequences. In addition, we generated the draft genome of the strain VRS3b, which was considered to be same as VRS3a based on its isolation from the same patient. We found that strain VRS3b did not harbor the genes responsible for tetracycline and gentamicin, which was further confirmed by the sensitivity towards these antibiotics. Our results suggest that the strains VRS3a and VRS3b are different from the view of antibiotic resistance and highlight the possibility of generation of two distinct VRSA strains from the same patient.
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Affiliation(s)
| | | | | | - Kazuhisa Sekimizu
- Teikyo University Institute of Medical Mycology.,Genome Pharmaceutical Institute Co., Ltd
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Sales DL, Oliveira OP, Cabral MES, Dias DQ, Kerntopf MR, Coutinho HDM, Costa JGM, Freitas FRD, Ferreira FS, Alves RRN, Almeida WO. Chemical identification and evaluation of the antimicrobial activity of fixed oil extracted from Rhinella jimi. PHARMACEUTICAL BIOLOGY 2015; 53:98-103. [PMID: 25289527 DOI: 10.3109/13880209.2014.911331] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
CONTEXT The toad Rhinella jimi (Stevaux, 2002) (Bufonidae) is used in traditional medicine to treat a number of illnesses (inflammation, infections, and wounds) in humans as well as animals. OBJECTIVES The present work examined the antimicrobial actions of the extracted oils from the body fat of R. jimi (ORJ) against fungi and standard and multi-resistant lines of bacteria, as well as their effects when combined with aminoglycosides. MATERIALS AND METHODS The toads were collected in the municipality of Exu in Pernambuco State, Brazil, and their body fat oils extracted in a Soxhlet apparatus using hexane. A gas chromatograph coupled to a mass spectrometer was used to identify the fatty acids, based on their methyl esters. The antimicrobial activities of the oil were analyzed against standard and multi-resistant lines of Escherichia coli, Staphylococcus aureus, and Pseudomonas aeruginosa, as well as against fungal lines of Candida albicans and Candida krusei using the broth micro-dilution method. RESULTS The minimum inhibitory concentrations (MIC) of ORJ were 512 µg/mL for Candida krusei and ≥1024 µg/mL for the other microorganisms. When associated with amikacin, ORJ demonstrated an increase in its ability to inhibit E. coli growth (from 156.25 to 39.06 µg/mL), indicating synergistic interaction. In the same way, when allied with amikacin, gentamicin, and neomycin, the ORJ reduced the MICs meaningly, against P. aeruginosa. CONCLUSIONS These data will enable searches to be made to obtain new products in combination with antibiotics, enhancing the efficacy of these drugs against drug-resistant microorganisms.
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Affiliation(s)
- Débora Lima Sales
- Programa de Pós-graduação em Etnobiologia e Conservação da Natureza, Universidade Federal Rural de Pernambuco - UFRPE , Recife, PE , Brazil
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Oliveira OP, Sales DL, Dias DQ, Cabral MES, Araújo Filho JA, Teles DA, Sousa JGG, Ribeiro SC, Freitas FRD, Coutinho HDM, Kerntopf MR, da Costa JGM, Alves RRN, Almeida WO. Antimicrobial activity and chemical composition of fixed oil extracted from the body fat of the snake Spilotes pullatus. PHARMACEUTICAL BIOLOGY 2014; 52:740-744. [PMID: 24559315 DOI: 10.3109/13880209.2013.868495] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
CONTEXT Ethnozoological studies have shown that Spilotes pullatus Linn. (Colubridae: Ophidia), is associated with medicinal and magic-religious uses in Brazil. OBJECTIVES This study was designed to determine the chemical composition of the oil extracted from the body fat of S. pullatus and to test its antimicrobial properties, alone and in association with aminoglycosides, against fungi and bacterial strains in concentrations ranging between 1024 and 0.5 µg/mL. MATERIAL AND METHODS The snakes were collected in the Chapada do Araripe, county of Crato, Ceará State, Brazil. The oil was extracted in a Soxhlet apparatus using hexane. The methyl esters of the fatty acids present in the samples were identified using GC-MS. The antimicrobial and drug modulatory activities of oil were tested by microdilution against fungal and bacterial strains. RESULTS The chemical composition of the fixed oils of S. pullatus identified 10 constituents representing 94.97% of the total sample. The percentages of saturated and unsaturated fatty acids were 33.59 and 61.38%, respectively, with the most abundant components being elaidic (37.26%). The oil did not demonstrate any antimicrobial or antifungal activity when tested alone, presenting MIC values ≥ 1024 µg/mL. However, when associated with antibiotics, it demonstrated synergistic effects with gentamicin against all the bacterial lineages assayed, and antagonistic effects with amikacin and neomycin against strains of Escherichia coli. CONCLUSIONS Oil extracted from the body fat of S. pullatus did not demonstrate any inhibitory effects on bacterial or fungal activities, but was effective in modulating the effects of certain antibiotics.
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Affiliation(s)
- O P Oliveira
- Universidade Regional do Cariri - URCA, Departamento de Qu쬩ca Biológica , Crato, CE , Brazil
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Coutinho H, Costa J, Falcão-Silva V, Siqueira-Júnior J, Lima E. Fruits to potentiate the antibiotic activity: The effect of Eugenia unifloraand Eugenia jambolanumL. against MRSA. ACTA ALIMENTARIA 2012. [DOI: 10.1556/aalim.2011.0004] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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Privett BJ, Nutz ST, Schoenfisch MH. Efficacy of surface-generated nitric oxide against Candida albicans adhesion and biofilm formation. BIOFOULING 2010; 26:973-83. [PMID: 21082455 PMCID: PMC3566635 DOI: 10.1080/08927014.2010.534552] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/15/2023]
Abstract
This report details the efficacy of nitric oxide (NO)-releasing xerogel surfaces composed of N-(6-aminohexyl)aminopropyl trimethoxysilane (AHAP3) and isobutyltrimethoxysilane (BTMOS) against Candida albicans adhesion, viability, and biofilm formation. A parallel plate flow cell assay was used to examine the effect of NO on planktonic fungal cells. Nitric oxide fluxes as low as 14 pmol cm(-2) s(-1) were sufficient to reduce fungal adhesion by ∼49% over the controls after 90 min. By utilizing a fluorescence live/dead assay and replicate plating, NO flux was determined to reduce fungal viability in a dose-dependent manner. The formation of C. albicans biofilms on NO-releasing xerogel-coated silicon rubber (SiR) coupons was impeded when compared to control (non-NO-releasing) and bare SiR surfaces. The synergistic efficacy of NO and silver sulfadiazine against adhered fungal cells and biofilms is reported with increased killing and biofilm inhibition over NO alone.
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Affiliation(s)
- Benjamin J. Privett
- Department of Chemistry, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
| | - Steven T. Nutz
- Department of Chemistry, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
| | - Mark H. Schoenfisch
- Department of Chemistry, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
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Coutinho HDM, Costa JGM, Falcão-Silva VS, Siqueira-Júnior JP, Lima EO. In vitro additive effect of Hyptis martiusii in the resistance to aminoglycosides of methicillin-resistant Staphylococcus aureus. PHARMACEUTICAL BIOLOGY 2010; 48:1002-1006. [PMID: 20731551 DOI: 10.3109/13880200903382686] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
CONTEXT Bacterial infectious agents represent a risk to populations, where they are responsible for the high morbidity and mortality. In combating these pathogens, our main line of defense is the use of antibiotics. However, the indiscriminate use of these drugs select resistant strains to these same drugs. OBJECTIVE In this study the ethanol extract of Hyptis martiusii Benth. (EEHM) (Lamiaceae) was tested for its antimicrobial activity against aminoglycoside multi-resistant Staphylococcus aureus (MRSA). MATERIALS AND METHODS In this study, the ethanol extract of H. martiusii was prepared and tested with chlorpromazine for its antimicrobial activity using the microdilution method. Chlorpromazine and the ethanol extract were used alone and also in combination with aminoglycosides against a MRSA strain resistant to these antibiotics to determine the participation of efflux systems in resistance mechanisms. The FIC index was calculated and evaluated by the checkerboard method. RESULTS A potentiating effect between this extract and aminoglycosides was demonstrated. Similarly, a potentiating effect of chlorpromazine with kanamycin was detected, indicating the involvement of an efflux system in the resistance to this aminoglycoside. The checkerboard method with combinations of aminoglycosides and EEHM demonstrated additive effect with kanamycin and gentamicin. It is therefore suggested that extracts from H. martiusii could be used as a source of plant-derived natural products with resistance- modifying activity. CONCLUSION This is the first report about the modifying antibiotic activity of Hyptis martiusii, constituting a new approach against bacterial resistance to antibiotics as aminoglycosides.
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Affiliation(s)
- Henrique D M Coutinho
- Laboratory of Research in Natural Products, University of the Region of Cariri, Crato, CE, Brazil.
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Ferreira FS, Brito SV, Costa JGM, Alves RRN, Coutinho HDM, Almeida WDO. Is the body fat of the lizard Tupinambis merianae effective against bacterial infections? JOURNAL OF ETHNOPHARMACOLOGY 2009; 126:233-7. [PMID: 19723574 DOI: 10.1016/j.jep.2009.08.038] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/29/2009] [Revised: 08/17/2009] [Accepted: 08/23/2009] [Indexed: 05/10/2023]
Abstract
AIM OF THE STUDY Tupinambis merianae is one of the animals that is most frequently used for medicinal purposes in Brazil as its body fat has many therapeutic indications in local folk medicine. This work presents the chemical compositions of the body fat of Tupinambis merianae and evaluates the antibacterial activity of the body fat as well as the ecological implications of its use in traditional medicine. MATERIALS AND METHODS Oil (OTM) was extracted from body fat located in the ventral region of Tupinambis merianae using hexane as a solvent. Fatty acids were determined indirectly using their corresponding methyl esters. The antibacterial activity of OTM was tested against standard as well as multi-resistant lines of Escherichia coli and Staphylococcus aureus, either alone or in combination with antibiotics and UV-A light. RESULTS Body fat of Tupinambis merianae presents 57% and 43% of unsaturated and saturated fatty acids respectively. Our results indicated that OTM did not demonstrate relevant antibacterial activity against any of the lines of Escherichia coli or Staphylococcus aureus, nor when combined with antibiotics or with UV-A light. CONCLUSIONS In light of these results, we recommend (i) development of management plans for a sustainable and rational use of Tupinambis merianae reducing the possible pressure on this species; and (ii) more studies be focused on the use of OTM and other natural products derived from animals that are used to treat other illnesses.
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Affiliation(s)
- Felipe S Ferreira
- Universidade Federal da Paraíba - UFPB, Centro de Ciências Exatas e da Natureza, Departamento de Sistemática e Ecologia, Campus I, João Pessoa, PB, Brazil. ferreira
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Coutinho HDM, Costa JGM, Falcão-Silva VS, Siqueira-Júnior JP, Lima EO. Effect of Momordica charantia L. in the resistance to aminoglycosides in methicilin-resistant Staphylococcus aureus. Comp Immunol Microbiol Infect Dis 2009; 33:467-71. [PMID: 19732954 DOI: 10.1016/j.cimid.2009.08.001] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2009] [Revised: 07/14/2009] [Accepted: 08/04/2009] [Indexed: 11/16/2022]
Abstract
In this study the ethanol extract (EEMC) of Momordica charantia L. (Cucurbitaceae) was tested for its modifying antibiotic activity against a MRSA strain. The growth of an MRSA (SA358) in the absence and presence of aminoglycosides was evaluated. A potentiating effect between this extract and all aminoglycosides was demonstrated. Similarly, the same effect was shown by chlorpromazine on kanamycin, gentamicin and neomycin, indicating the involvement of an efflux system in the resistance to these aminoglycosides. Extracts from M. charantia could be used as a source of plant-derived natural products with resistance-modifying activity. This is the first report about the modifying antibiotic activity of M. charantia, constituting a new weapon against multi-resistant bacteria such as MRSA.
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Affiliation(s)
- Henrique D M Coutinho
- Laboratory of Research in Natural Products, University of the Region of Cariri, Crato (CE), Brazil.
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Coutinho HDM, Costa JGM, Lima EO, Falcão-Silva VS, Siqueira Júnior JP. Herbal therapy associated with antibiotic therapy: potentiation of the antibiotic activity against methicillin--resistant Staphylococcus aureus by Turnera ulmifolia L. BMC COMPLEMENTARY AND ALTERNATIVE MEDICINE 2009; 9:13. [PMID: 19426487 PMCID: PMC2685411 DOI: 10.1186/1472-6882-9-13] [Citation(s) in RCA: 92] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 01/22/2009] [Accepted: 05/08/2009] [Indexed: 11/16/2022]
Abstract
Background Staphylococcus genus is widely spread in nature being part of the indigenous microbiota of skin and mucosa of animal and birds. Some Staphylococcus species are frequently recognized as etiological agents of many animal and human opportunistic infections This is the first report testing the antibiotic resistance-modifying activity of Turnera ulmifolia against methicillin-resistant Staphylococcus aureus – MRSA strain. Methods In this study an ethanol extract of Turnera ulmifolia L. and chlorpromazine were tested for their antimicrobial activity alone or in combination with aminoglycosides against an MRSA strain. Results The synergism of the ethanol extract and aminoglycosides were verified using microdillution method. A synergistic effect of this extract on gentamicin and kanamycin was demonstrated. Similarly, a potentiating effect of chlorpromazine on kanamycin, gentamicin and neomycin, indicating the involvement of an efflux system in the resistance to these aminoglycosides. Conclusion It is therefore suggested that extracts from Turnera ulmifolia could be used as a source of plant-derived natural products with resistance-modifying activity, constituting a new weapon against the problem of bacterial resistance to antibiotics demonstrated in MRSA strains.
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D'Elia MA, Pereira MP, Chung YS, Zhao W, Chau A, Kenney TJ, Sulavik MC, Black TA, Brown ED. Lesions in teichoic acid biosynthesis in Staphylococcus aureus lead to a lethal gain of function in the otherwise dispensable pathway. J Bacteriol 2006; 188:4183-9. [PMID: 16740924 PMCID: PMC1482942 DOI: 10.1128/jb.00197-06] [Citation(s) in RCA: 156] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
An extensive study of teichoic acid biosynthesis in the model organism Bacillus subtilis has established teichoic acid polymers as essential components of the gram-positive cell wall. However, similar studies pertaining to therapeutically relevant organisms, such as Staphylococcus aureus, are scarce. In this study we have carried out a meticulous examination of the dispensability of teichoic acid biosynthetic enzymes in S. aureus. By use of an allelic replacement methodology, we examined all facets of teichoic acid assembly, including intracellular polymer production and export. Using this approach we confirmed that the first-acting enzyme (TarO) was dispensable for growth, in contrast to dispensability studies in B. subtilis. Upon further characterization, we demonstrated that later-acting gene products (TarB, TarD, TarF, TarIJ, and TarH) responsible for polymer formation and export were essential for viability. We resolved this paradox by demonstrating that all of the apparently indispensable genes became dispensable in a tarO null genetic background. This work suggests a lethal gain-of-function mechanism where lesions beyond the initial step in wall teichoic acid biosynthesis render S. aureus nonviable. This discovery poses questions regarding the conventional understanding of essential gene sets, garnered through single-gene knockout experiments in bacteria and higher organisms, and points to a novel drug development strategy targeting late steps in teichoic acid synthesis for the infectious pathogen S. aureus.
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Affiliation(s)
- Michael A D'Elia
- Department of Biochemistry and Biomedical Sciences, Health Science Centre 4H32, 1200 Main St., W. Hamilton, ON L8N 3Z5, Canada
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