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Guidone GHM, Cardozo JG, Silva LC, Sanches MS, Galhardi LCF, Kobayashi RKT, Vespero EC, Rocha SPD. Epidemiology and characterization of Providencia stuartii isolated from hospitalized patients in southern Brazil: a possible emerging pathogen. Access Microbiol 2023; 5:000652.v4. [PMID: 37970084 PMCID: PMC10634494 DOI: 10.1099/acmi.0.000652.v4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2023] [Accepted: 10/08/2023] [Indexed: 11/17/2023] Open
Abstract
This study aimed to characterize the virulence factors and antimicrobial resistance of Providencia stuartii , an opportunistic pathogen that causes human infections. We examined 45 isolates of P. stuartii both genotypically and phenotypically by studying their adherence to HeLa cells, biofilm formation, cytotoxicity and antimicrobial resistance, and analysed their genomes for putative virulence and resistance genes. This study found that most isolates possessed multiple virulence genes, including fimA, mrkA, fptA, iutA, ireA and hlyA, and were cytotoxic to Vero cells. All the isolates were resistant to amoxicillin plus clavulanic acid, levofloxacin and sulfamethoxazole plus trimethoprim, and most were resistant to ceftriaxone and cefepime. All isolates harboured extended-spectrum beta-lactamase coding genes such as bla CTX-M-2 and 23/45(51.11 %) of them also harboured bla CTX-M-9. The gene KPC-2 (carbapenemase) was detected in 8/45(17.77 %) isolates. This study also found clonality among the isolates, indicating the possible spread of the pathogen among patients at the hospital. These results have significant clinical and epidemiological implications and emphasize the importance of a continued understanding of the virulence and antimicrobial resistance of this pathogen for the prevention and treatment of future infections.
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Affiliation(s)
| | - Jennifer Germiniani Cardozo
- Laboratory of Basic and Applied Bacteriology, Department of Microbiology, Center of Biological Sciences, State University of Londrina, Londrina, Brazil
| | - Luana Carvalho Silva
- Laboratory of Bacteriology, Department of Microbiology, Center of Biological Sciences, State University of Londrina, Londrina, Brazil
| | - Matheus Silva Sanches
- Laboratory of Bacteriology, Department of Microbiology, Center of Biological Sciences, State University of Londrina, Londrina, Brazil
| | - Ligia Carla Faccin Galhardi
- Virology Laboratory, Department of Microbiology, Center of Biological Sciences, State University of Londrina, Londrina, Brazil
| | - Renata Katsuko Takayama Kobayashi
- Laboratory of Basic and Applied Bacteriology, Department of Microbiology, Center of Biological Sciences, State University of Londrina, Londrina, Brazil
| | - Eliana Carolina Vespero
- Department of Pathology, Clinical and Toxicological Analysis, Health Sciences Center, University Hospital of Londrina, State University of Londrina, Paraná, Brazil
| | - Sergio Paulo Dejato Rocha
- Laboratory of Bacteriology, Department of Microbiology, Center of Biological Sciences, State University of Londrina, Londrina, Brazil
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Zarezadeh M, Mahmoudinezhad M, Hosseini B, Khorraminezhad L, Razaghi M, Alvandi E, Saedisomeolia A. Dietary pattern in autism increases the need for probiotic supplementation: A comprehensive narrative and systematic review on oxidative stress hypothesis. Clin Nutr 2023; 42:1330-1358. [PMID: 37418842 DOI: 10.1016/j.clnu.2023.06.014] [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: 02/28/2023] [Revised: 05/15/2023] [Accepted: 06/11/2023] [Indexed: 07/09/2023]
Abstract
Autism spectrum disorders (ASDs) are associated with specific dietary habits, including limited food selection and gastrointestinal problems, resulting in an altered gut microbiota. Autistic patients have an elevated abundance of certain gut bacteria associated with increased oxidative stress in the gastrointestinal tract. Probiotic supplementation has been shown to decrease oxidative stress in a simulated gut model, but the antioxidant effects of probiotics on the oxidative stress of the gut in autistic patients have not been directly studied. However, it is speculated that probiotic supplementation may help decrease oxidative stress in the gastrointestinal tract of autistic patients due to their specific dietary habits altering the microbiota. PubMed, Scopus and Web of Science databases and Google Scholar were searched up to May 2023. This systematic-narrative review aims to present the latest evidence regarding the changes in eating habits of autistic children which may further increase the gut microbiota induced oxidative stress. Additionally, this review will assess the available literature on the effects of probiotic supplementation on oxidative stress parameters.
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Affiliation(s)
- Meysam Zarezadeh
- Student Research Committee, Tabriz University of Medical Sciences, Tabriz, Iran
| | | | - Banafshe Hosseini
- Clinical Research and Knowledge Transfer Unit on Childhood Asthma, Research Centre, Sainte-Justine University Health Centre, Montreal, QC H3T 1C5, Canada
| | - Leila Khorraminezhad
- School of Human Nutrition, McGill University, Ste-Anne-de-Bellevue, Québec, Canada
| | - Maryam Razaghi
- Department of Nutritional Sciences, Faculty of Medicine, University of Toronto, Toronto, ON, Canada
| | - Ehsan Alvandi
- School of Medicine, Western Sydney University, NSW, Australia
| | - Ahmad Saedisomeolia
- School of Human Nutrition, McGill University, Ste-Anne-de-Bellevue, Québec, Canada.
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Tvrdá E, Petrovičová M, Benko F, Ďuračka M, Galovičová L, Slanina T, Kačániová M. Curcumin Attenuates Damage to Rooster Spermatozoa Exposed to Selected Uropathogens. Pharmaceutics 2022; 15:65. [PMID: 36678694 PMCID: PMC9861644 DOI: 10.3390/pharmaceutics15010065] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2022] [Revised: 12/18/2022] [Accepted: 12/21/2022] [Indexed: 12/28/2022] Open
Abstract
Artificial insemination, as an essential pillar of the modern poultry industry, primarily depends on the quality of semen collected from stud roosters. Since the collection and storage of ejaculates is not a sterile process, antimicrobial agents have become essential supplements to semen extenders. While the use of traditional antibiotics has been challenged because of rising bacterial resistance, natural biomolecules represent an appealing alternative because of their antibacterial and antioxidant properties. As such, this study strived to compare the effects of 50 μmol/L curcumin (CUR) with 31.2 µg/mL kanamycin (KAN) as a conventional antibiotic on rooster sperm quality in the presence of Salmonella enterica, Escherichia coli and Pseudomonas aeruginosa. Changes in sperm structural integrity and functional activity were monitored at 2 and 24 h of culture. Computer-assisted semen analysis revealed significant sperm motility preservation following treatment with KAN, particularly in the case of Salmonella enterica and Pseudomonas aeruginosa (p < 0.001) after 24 h. On the other hand, CUR was more effective in opposing ROS overproduction by all bacteria (p < 0.05), as determined by luminol-based luminometry, and maintained sperm mitochondrial activity (p < 0.001 in the case of Salmonella enterica; p < 0.05 with respect to Escherichia coli and Pseudomonas aeruginosa), as assessed by the fluorometric JC-1 assay. The TUNEL assay revealed that CUR readily preserved the DNA integrity of rooster sperm exposed to Salmonella enterica (p < 0.01) and Escherichia coli (p < 0.001). The bacteriological analysis showed higher efficiency of KAN in preventing the growth of all selected bacterial species (p < 0.0001) as opposed to CUR. In conclusion, CUR provided protection to rooster spermatozoa against alterations caused by uropathogens, most likely through its antioxidant activity. Hence, CUR supplementation to poultry semen extenders in combination with properly selected antibacterial substances may become an interesting strategy in the management of bacterial contamination during semen storage.
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Affiliation(s)
- Eva Tvrdá
- Institute of Biotechnology, Faculty of Biotechnology and Food Sciences, Slovak University of Agriculture in Nitra, Tr. A. Hlinku 2, 949 76 Nitra, Slovakia
| | - Michaela Petrovičová
- Institute of Applied Biology, Faculty of Biotechnology and Food Sciences, Slovak University of Agriculture in Nitra, Tr. A. Hlinku 2, 949 76 Nitra, Slovakia
- Department of Neuroscience, Second Faculty of Medicine (2. LF UK), V Úvalu 84, 150 06 Prague, Czech Republic
| | - Filip Benko
- Institute of Applied Biology, Faculty of Biotechnology and Food Sciences, Slovak University of Agriculture in Nitra, Tr. A. Hlinku 2, 949 76 Nitra, Slovakia
| | - Michal Ďuračka
- AgroBioTech Research Centre, Slovak University of Agriculture in Nitra, Tr. A. Hlinku 2, 949 76 Nitra, Slovakia
| | - Lucia Galovičová
- Department of Fruit Science, Viticulture and Enology, Faculty of Horticulture and Landscape Engineering, Slovak University of Agriculture in Nitra, Tr. A. Hlinku 2, 949 76 Nitra, Slovakia
| | - Tomáš Slanina
- Institute of Applied Biology, Faculty of Biotechnology and Food Sciences, Slovak University of Agriculture in Nitra, Tr. A. Hlinku 2, 949 76 Nitra, Slovakia
| | - Miroslava Kačániová
- Department of Fruit Science, Viticulture and Enology, Faculty of Horticulture and Landscape Engineering, Slovak University of Agriculture in Nitra, Tr. A. Hlinku 2, 949 76 Nitra, Slovakia
- Department of Bioenergetics, Food Analysis and Microbiology, Institute of Food Technology and Nutrition, University of Rzeszow, Cwiklinskiej 1, 35-601 Rzeszow, Poland
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Quinteros MA, Tolosa J, García-Martínez JC, Páez PL, Paraje MG. Synergic activity of oligostyrylbenzenes with amphotericin B against Candida tropicalis biofilms. Yeast 2021; 38:634-645. [PMID: 34596268 DOI: 10.1002/yea.3672] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2020] [Revised: 09/14/2021] [Accepted: 09/17/2021] [Indexed: 11/12/2022] Open
Abstract
Antimicrobial drug resistance is a serious challenge in clinical settings worldwide, with biofilm formation having been associated with this problem. In the present study, the synergism of oligostyrylbenzene (OSB) compounds in combination with amphotericin B (AmB) against Candida tropicalis biofilms was investigated. In addition, the toxicity in human blood cells was determined. Synergistic combinations of OSBs and AmB were evaluated to consider future effects of OSBs in vivo. The checkerboard microdilution method was used to study the interactions of one anionic (1) and two cationic (2 and 3) OSBs with AmB. We investigated the effects of OSBs on reactive oxygen species (ROS) and the levels of the reactive nitrogen intermediates (RNIs). The cellular stress affected biofilm growth through an accumulation of ROS and RNI, at synergistic concentrations of OSBs and AmB. Furthermore, significant surface topography differences were noted upon treatment with the OSB 2/AmB combination, using confocal laser scanning microscopy in conjunction with the image analysis software COMSTAT. The results revealed a low toxicity to leukocytes and red blood cells at synergistic combinations of cationic OSBs with AmB. These findings demonstrated the antibiofilm effects of OSBs and the synergism of AmB with cationic OSBs against biofilms of C. tropicalis for the first time.
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Affiliation(s)
- Melisa A Quinteros
- Multidisciplinary Institute of Plant Biology (IMBIV), National Council for Scientific and Technical Research (CONICET), Córdoba, Argentina.,Deparment of Microbiology, Faculty of Exact, Physical and Natural Sciences, National University of Córdoba, Córdoba, Argentina
| | - Juan Tolosa
- Albacete Faculty of Pharmacy, Regional Center for Biomedical Research, University of Castilla-La Mancha, Ciudad Real, Spain
| | - Joaquín C García-Martínez
- Albacete Faculty of Pharmacy, Regional Center for Biomedical Research, University of Castilla-La Mancha, Ciudad Real, Spain
| | - Paulina L Páez
- Deparment of Microbiology, Faculty of Exact, Physical and Natural Sciences, National University of Córdoba, Córdoba, Argentina.,Department of Pharmaceutical Sciences, Faculty of Chemical Sciences, National University of Córdoba, Córdoba, Argentina.,Research and Development Unit in Pharmaceutical Technology (UNITEFA), National Council for Scientific and Technical Research (CONICET), Córdoba, Argentina
| | - María G Paraje
- Multidisciplinary Institute of Plant Biology (IMBIV), National Council for Scientific and Technical Research (CONICET), Córdoba, Argentina.,Deparment of Microbiology, Faculty of Exact, Physical and Natural Sciences, National University of Córdoba, Córdoba, Argentina
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Chen JF, Liu Y, Tang GR, Jin D, Chen X, Pei Y, Fan YH. The secondary metabolite regulator, BbSmr1, is a central regulator of conidiation via the BrlA-AbaA-WetA pathway in Beauveria bassiana. Environ Microbiol 2020; 23:810-825. [PMID: 32691932 DOI: 10.1111/1462-2920.15155] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2020] [Revised: 06/27/2020] [Accepted: 07/04/2020] [Indexed: 01/21/2023]
Abstract
The filamentous fungus Beauveria bassiana, an insect fungal pathogen, is widely used for pest biocontrol. Aerial conidia are infectious propagules, and their yield and viability greatly affect the field application of this fungus; however, little is known about the molecular regulatory mechanism of the triggered conidiation. In the present study, we find that the secondary metabolite regulator BbSmr1 is involved in the regulation of asexual conidiation development and stress response in B. bassiana. A deficiency in Bbsmr1 results in a prominent fluffy-like phenotype on solid medium, decreased conidial yield, accelerated conidial germination, as well as increased tolerance to H2 O2 stress and cell wall inhibitors. The deletion of Bbsmr1 also leads to thickened conidial cell walls and changed cell epitopes. Overexpressing either BbbrlA or BbabaA in the ∆Bbsmr1 strain can rescue the phenotypes of conidial development and stress response. BbSmr1 activates BbbrlA transcription by directly binding to the A4GA3 sequence of the BbbrlA promoter. BbBrlA in turn binds to the promoter of Bbsmr1 and negatively regulates the expression of Bbsmr1. These results indicate that BbSmr1 positively regulates conidial development in B. bassiana by activating the central development pathway BrlA-AbaA-WetA and provides insights into the developmental regulatory mechanism of entomopathogenic fungi.
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Affiliation(s)
- Jin-Feng Chen
- State Key Laboratory of Silkworm Genome Biology, Biotechnology Research Center, Southwest University, Chongqing, 400716, China.,College of Biological and Chemical Engineering, Chongqing University of Education, Chongqing, 400067, China
| | - Yu Liu
- College of Biotechnology, Southwest University, Beibei, Chongqing, 400716, China
| | - Gui-Rong Tang
- State Key Laboratory of Silkworm Genome Biology, Biotechnology Research Center, Southwest University, Chongqing, 400716, China
| | - Dan Jin
- State Key Laboratory of Silkworm Genome Biology, Biotechnology Research Center, Southwest University, Chongqing, 400716, China
| | - Xi Chen
- State Key Laboratory of Silkworm Genome Biology, Biotechnology Research Center, Southwest University, Chongqing, 400716, China
| | - Yan Pei
- State Key Laboratory of Silkworm Genome Biology, Biotechnology Research Center, Southwest University, Chongqing, 400716, China
| | - Yan-Hua Fan
- State Key Laboratory of Silkworm Genome Biology, Biotechnology Research Center, Southwest University, Chongqing, 400716, China
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Escherichia coli ST131 clones harbouring AggR and AAF/V fimbriae causing bacteremia in Mozambican children: Emergence of new variant of fimH27 subclone. PLoS Negl Trop Dis 2020; 14:e0008274. [PMID: 32357189 PMCID: PMC7219792 DOI: 10.1371/journal.pntd.0008274] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2019] [Revised: 05/13/2020] [Accepted: 04/07/2020] [Indexed: 11/25/2022] Open
Abstract
Multidrug-resistant Escherichia coli ST131 fimH30 responsible for extra-intestinal pathogenic (ExPEC) infections is globally distributed. However, the occurrence of a subclone fimH27 of ST131 harboring both ExPEC and enteroaggregative E. coli (EAEC) related genes and belonging to commonly reported O25:H4 and other serotypes causing bacteremia in African children remain unknown. We characterized 325 E. coli isolates causing bacteremia in Mozambican children between 2001 and 2014 by conventional multiplex polymerase chain reaction and whole genome sequencing. Incidence rate of EAEC bacteremia was calculated among cases from the demographic surveillance study area. Approximately 17.5% (57/325) of isolates were EAEC, yielding an incidence rate of 45.3 episodes/105 children-years-at-risk among infants; and 44 of isolates were sequenced. 72.7% (32/44) of sequenced strains contained simultaneously genes associated with ExPEC (iutA, fyuA and traT); 88.6% (39/44) harbored the aggregative adherence fimbriae type V variant (AAF/V). Sequence type ST-131 accounted for 84.1% (37/44), predominantly belonging to serotype O25:H4 (59% of the 37); 95.6% (35/44) harbored fimH27. Approximately 15% (6/41) of the children died, and five of the six yielded ST131 strains (83.3%) mostly (60%; 3/5) due to serotypes other than O25:H4. We report the emergence of a new subclone of ST-131 E. coli strains belonging to O25:H4 and other serotypes harboring both ExPEC and EAEC virulence genes, including agg5A, associated with poor outcome in bacteremic Mozambican children, suggesting the need for prompt recognition for appropriate management. Escherichia coli ST131 has emerged as a globally disseminated multi-drug resistant clone associated with extra-intestinal infections acquired in the community or hospital. In Manhiça district, E. coli is among the top five leading bloodstream pathogens in children. We characterized E. coli strains causing bacteremia in young children in a rural hospital of Mozambique, providing novel information on the occurrence of a new subclone of ST131 harboring both ExPEC and EAEC related genes and belonging to commonly reported O25:H4 and other serotypes. These data suggest the need for further understanding of pathogenesis and clinical impact of this new entity to inform prompt recognition and appropriate treatment.
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Marioni J, Arce JE, Cabrera JL, Paraje MG, Núñez Montoya SC. Reduction of Candida tropicalis biofilm by photoactivation of a Heterophyllaea pustulata extract. PHARMACEUTICAL BIOLOGY 2016; 54:2791-2801. [PMID: 27256704 DOI: 10.1080/13880209.2016.1183683] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/17/2016] [Revised: 04/05/2016] [Accepted: 04/24/2016] [Indexed: 06/05/2023]
Abstract
CONTEXT Biofilm formation is an important problem, since this growth mode confers resistance to drugs usually used in therapeutics. OBJECTIVE In vitro antifungal activity of extracts obtained from Heterophyllaea pustulata Hook f. (Rubiaceae) were studied against Candida tropicalis biofilms, evaluating the effect of irradiation and the oxidative and nitrosative stresses as possible mechanisms of action. MATERIALS AND METHODS Hexane, benzene, ethyl acetate and ethanol extracts were evaluated at three concentrations (0.2, 0.1 and 0.05 mg/mL) over mature biofilm, under darkness and irradiation. After 48 h of incubation, biofilm quantitation was performed by the O'Toole and Kolter method. Reactive oxygen species (ROS) was measured by nitro-blue tetrazolium (NBT) reaction and reactive nitrogen intermediates (RNI) by the Griess reagent. Superoxide dismutase activation (SOD, NBT assay) and total antioxidant system (FRAP test) were studied. RESULTS Only the benzene extract at 0.2 mg/mL reduced the biofilms formation. The slight decrease achieved in darkness (17.06 ± 2.80% reduction) was increased by light action (39.31 ± 3.50% reduction), clearly observing a photostimulation. This great reduction was confirmed by confocal microscopy. In darkness, biofilm reduction was mediated by an increase in RNI, whereas under irradiation, the ROS action was most important. Although no SOD activation was observed, a strong stimulation of the total antioxidant system was detected. HPLC analysis established a high content of several anthraquinones in this extract. DISCUSSION AND CONCLUSION Biofilm reduction by benzene extract was mainly mediated by oxidative stress triggered under light action, confirming a photodynamic sensitization, which could be attributed to its high content of photosensitizing anthraquinones.
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Affiliation(s)
- Juliana Marioni
- a IMBIV-CONICET, Departamento De Farmacia, Facultad De Ciencias Químicas , Universidad Nacional De Córdoba , Córdoba , Argentina
- b IMBIV-CONICET , Cátedra De Microbiología, Facultad De Ciencias Exactas Físicas Y Naturales . Universidad Nacional De Córdoba , Córdoba , Argentina
| | - Julio E Arce
- b IMBIV-CONICET , Cátedra De Microbiología, Facultad De Ciencias Exactas Físicas Y Naturales . Universidad Nacional De Córdoba , Córdoba , Argentina
| | - José L Cabrera
- a IMBIV-CONICET, Departamento De Farmacia, Facultad De Ciencias Químicas , Universidad Nacional De Córdoba , Córdoba , Argentina
| | - María G Paraje
- b IMBIV-CONICET , Cátedra De Microbiología, Facultad De Ciencias Exactas Físicas Y Naturales . Universidad Nacional De Córdoba , Córdoba , Argentina
| | - Susana C Núñez Montoya
- a IMBIV-CONICET, Departamento De Farmacia, Facultad De Ciencias Químicas , Universidad Nacional De Córdoba , Córdoba , Argentina
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Peralta MA, da Silva MA, Ortega MG, Cabrera JL, Paraje MG. Antifungal activity of a prenylated flavonoid from Dalea elegans against Candida albicans biofilms. PHYTOMEDICINE : INTERNATIONAL JOURNAL OF PHYTOTHERAPY AND PHYTOPHARMACOLOGY 2015; 22:975-980. [PMID: 26407939 DOI: 10.1016/j.phymed.2015.07.003] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/29/2014] [Revised: 06/19/2015] [Accepted: 07/04/2015] [Indexed: 06/05/2023]
Abstract
BACKGROUND The continuing emergence of infections with antifungal resistant Candida strains requires a constant search for new antifungal drugs, with the plant kingdom being an important source of chemical structures. PURPOSE The present study investigated the antifungal effect of 2',4'-dihydroxy-5'-(1''',1'''-dimethylallyl)-8-prenylpinocembrin (8PP, formerly 6PP), a natural prenylflavonoid, on Candida albicans biofilms, and compared this with an azole antifungal (fluconazole) by studying the cellular stress and antioxidant response. STUDY DESIGN/METHODS The fluconazole sensitive (SCa) and azole-resistant (RCa) C. albicans strains were used, with biofilm formation being studied using crystal violet (CV) and confocal scanning laser microscopy (CSLM). The minimal inhibitory concentration for sessile cells (SMIC) was defined as the concentration of antifungal that caused a 50% (SMIC 50) and 80% (SMIC 80) reduction of treated biofilms. The reactive oxygen species (ROS) were detected by the reduction of nitro blue tetrazolium (NBT), and reactive nitrogen intermediates (RNI) were determined by the Griess assay. The activities of the superoxide dismutase (SOD) and catalase (CAT) antioxidant enzymes and the total antioxidant capacity of the biofilms were measured by spectrophotometric methods. ROS accumulation was also detected inside biofilms by using the fluorogenic dye 2',7'-dichlorodihydrofluorescein diacetate (DCFH-DA), which was visualized by CSLM. RESULTS The SCa and RCa biofilms were strongly inhibited by 8PP at 100 µM (SMIC 80). We observed that cellular stress affected biofilms growth, resulting in an increase of ROS and also of reactive nitrogen intermediates (RNI), with SOD and CAT being increased significantly in the presence of 8PP. The basal level of the biofilm total antioxidant capacity was higher in RCa than SCa. Moreover, in SCa, the total antioxidant capacity rose considerably in the presence of both 8PP and fluconazole. CONCLUSION Our data suggest that 8PP may be useful for the treatment of biofilm-related Candida infections, through an accumulation of endogenous ROS and RNI that can induce an adaptive response based on a coordinated increase in antioxidant defenses. 8PP may also have a therapeutic potential in C. albicans infections.
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Affiliation(s)
- Mariana Andrea Peralta
- Departamento de Farmacia, Facultad de Ciencias Químicas, Instituto Multidisciplinario de Biología Vegetal (IMBIV) - Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Universidad Nacional de Córdoba, Haya de la Torre y Medina Allende, 5000 Córdoba, Argentina
| | - María Angel da Silva
- Facultad de Ciencias Exactas Físicas y Naturales, Instituto Multidisciplinario de Biología Vegetal (IMBIV) - Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET); Cátedra de Microbiología, Universidad Nacional de Córdoba, Av. Vélez Sarsfield 299, Córdoba, Argentina
| | - María Gabriela Ortega
- Departamento de Farmacia, Facultad de Ciencias Químicas, Instituto Multidisciplinario de Biología Vegetal (IMBIV) - Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Universidad Nacional de Córdoba, Haya de la Torre y Medina Allende, 5000 Córdoba, Argentina
| | - José Luis Cabrera
- Departamento de Farmacia, Facultad de Ciencias Químicas, Instituto Multidisciplinario de Biología Vegetal (IMBIV) - Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Universidad Nacional de Córdoba, Haya de la Torre y Medina Allende, 5000 Córdoba, Argentina
| | - María Gabriela Paraje
- Facultad de Ciencias Exactas Físicas y Naturales, Instituto Multidisciplinario de Biología Vegetal (IMBIV) - Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET); Cátedra de Microbiología, Universidad Nacional de Córdoba, Av. Vélez Sarsfield 299, Córdoba, Argentina.
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Angel Villegas N, Baronetti J, Albesa I, Etcheverría A, Becerra MC, Padola NL, Paraje MG. Effect of antibiotics on cellular stress generated in Shiga toxin-producing Escherichia coli O157:H7 and non-O157 biofilms. Toxicol In Vitro 2015; 29:1692-700. [PMID: 26130220 DOI: 10.1016/j.tiv.2015.06.025] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2014] [Revised: 06/25/2015] [Accepted: 06/26/2015] [Indexed: 11/28/2022]
Abstract
Shiga toxin-producing Escherichia coli (STEC) are important food-borne pathogens, with the main virulence factor of this bacterium being its capacity to secrete Shiga toxins (Stxs). Therefore, the use of certain antibiotics for the treatment of this infection, which induces the liberation of Stxs, is controversial. Reactive oxygen and nitrogen species are also involved in the pathogenesis of different diseases. The purpose of this study was to analyze the effects of antibiotics on biofilms of STEC and the relationships between cellular stress and the release of Stx. To this end, biofilms of reference and clinical strains were treated with antibiotics (ciprofloxacin, fosfomycin and rifaximin) and the production of oxidants, the antioxidant defense system and toxin release were evaluated. Ciprofloxacin altered the prooxidant-antioxidant balance, with a decrease of oxidant metabolites and an increase of superoxide dismutase and catalase activity, being associated with high-levels of Stx production. Furthermore, inhibition of oxidative stress by exogenous antioxidants was correlated with a reduction in the liberation of Stx, indicating the participation of this phenomenon in the release of this toxin. In contrast, fosfomycin and rifaximin produced less alteration with a minimal production of Stx. Our data show that treatment of biofilm-STEC with these antibiotics induces oxidative stress-mediated release of Stx.
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Affiliation(s)
- Natalia Angel Villegas
- IMBIV-CONICET y Departamento de Farmacia, Facultad de Ciencias Químicas, Universidad Nacional de Córdoba, Argentina
| | - José Baronetti
- IMBIV-CONICET y Cátedra de Microbiología, Facultad de Ciencias Exactas Físicas y Naturales, Universidad Nacional de Córdoba, Argentina
| | - Inés Albesa
- IMBIV-CONICET y Departamento de Farmacia, Facultad de Ciencias Químicas, Universidad Nacional de Córdoba, Argentina
| | - Analía Etcheverría
- Laboratorio de Inmunoquímica y Biotecnología, Dpto. SAMP, Facultad de Ciencias Veterinarias, Universidad Nacional del Centro de la Provincia de Buenos Aires, Tandil, Argentina
| | - M Cecilia Becerra
- IMBIV-CONICET y Departamento de Farmacia, Facultad de Ciencias Químicas, Universidad Nacional de Córdoba, Argentina
| | - Nora L Padola
- Laboratorio de Inmunoquímica y Biotecnología, Dpto. SAMP, Facultad de Ciencias Veterinarias, Universidad Nacional del Centro de la Provincia de Buenos Aires, Tandil, Argentina
| | - M Gabriela Paraje
- IMBIV-CONICET y Cátedra de Microbiología, Facultad de Ciencias Exactas Físicas y Naturales, Universidad Nacional de Córdoba, Argentina.
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Relevance of biofilms in the pathogenesis of Shiga-toxin-producing Escherichia coli infection. ScientificWorldJournal 2013; 2013:607258. [PMID: 24324376 PMCID: PMC3845835 DOI: 10.1155/2013/607258] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2013] [Accepted: 09/25/2013] [Indexed: 11/17/2022] Open
Abstract
The present study was designed to determine the relationships among biofilm formation, cellular stress and release of Shiga toxin (Stx) by three different clinical Shiga toxin-producing Escherichia coli (STEC) strains. The biofilm formation was determined using crystal violet stain in tryptic soy broth or thioglycollate medium with the addition of sugars (glucose or mannose) or hydrogen peroxide. The reactive oxygen species (ROSs) were detected by the reduction of nitro blue tetrazolium and reactive nitrogen intermediates (RNI) determined by the Griess assay. In addition, the activities of two antioxidant enzymes, superoxide dismutase (SOD) and catalase (CAT), were studied. For the cytotoxicity studies, Vero cells were cultured with Stx released of STEC biofilms. The addition of sugars in both culture mediums resulted in an increase in biofilm biomass, with a decrease in ROS and RNI production, low levels of SOD and CAT activity, and minimal cytotoxic effects. However, under stressful conditions, an important increase in the antioxidant enzyme activity and high level of Stx production were observed. The disturbance in the prooxidant-antioxidant balance and its effect on the production and release of Stx evaluated under different conditions of biofilm formation may contribute to a better understanding of the relevance of biofilms in the pathogenesis of STEC infection.
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