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Karamanlioglu M, Yesilkir-Baydar S. Characterization of gelatin-based wound dressing biomaterials containing increasing coconut oil concentrations. JOURNAL OF BIOMATERIALS SCIENCE. POLYMER EDITION 2024; 35:16-44. [PMID: 37773094 DOI: 10.1080/09205063.2023.2265624] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/28/2023] [Accepted: 09/22/2023] [Indexed: 09/30/2023]
Abstract
This study determined the influence and ideal ratios of various coconut oil (CO) amounts in gelatin (G) based-films as wound dressings since there are limited comparative studies to evaluate the sole effect of increasing CO on protein-based biomaterials. Homogenous films at G:CO ratio of 4:0,4:2,4:3,4:4 (w:w) corresponding to CO-0, CO-2, CO-3, CO-4, respectively, were obtained using solution casting. SEM showed CO caused rougher surfaces decreasing mechanical strength. However, no pores were observed in CO-4 due to bigger clusters of oil improving stretchability compared to CO-3; and durability since aging of CO-4 was >10% lower than CO-0 in aqueous media. FTIR showed triglycerides' band only in CO films with increasing amplitude. Moreover, amide-I of CO-2 was involved in more hydrogen bonding, therefore, CO-2 had the highest melt-like transition temperatures (Tmax) at ∼163 °C while others' were at ∼133 °C; and had more ideal mechanical properties among CO films. XTT showed that increased CO improved 3T3 cell viability as CO-0 significantly decreased viability at 10,50,75,100 μg/mL (p < 0.05), whereas CO-2 and CO-3 within 5-75 μg/mL and CO-4 within 5-100 μg/mL range increased viability ≥100% suggesting proliferation. All CO samples at 25 μg/mL stimulated 3T3 cell migration in Scratch Assay indicating wound healing. CO amounts mainly improved thermal and healing properties of gelatin-based biomaterial. CO-2 was more thermally stable and CO-4 had better influence on cell viability and wound healing than CO-0. Therefore, increased CO ratios, specifically 4:2 and 4:4, G:CO (w:w), in gelatin-based films can be ideal candidates for wound dressing materials.
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Affiliation(s)
| | - Serap Yesilkir-Baydar
- Department of Biomedical Engineering, Istanbul Gelisim University, Istanbul, Turkey
- Life Sciences and Biomedical Engineering Application and Research Center, Istanbul Gelisim University, Istanbul, Turkey
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Darie-Niță RN, Irimia A, Doroftei F, Stefan LM, Iwanczuk A, Trusz A. Bioactive and Physico-Chemical Assessment of Innovative Poly(lactic acid)-Based Biocomposites Containing Sage, Coconut Oil, and Modified Nanoclay. Int J Mol Sci 2023; 24:ijms24043646. [PMID: 36835080 PMCID: PMC9962215 DOI: 10.3390/ijms24043646] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2022] [Revised: 02/05/2023] [Accepted: 02/08/2023] [Indexed: 02/15/2023] Open
Abstract
The bioactivity of the versatile biodegradable biopolymer poly(lactic acid) (PLA) can be obtained by combining it with natural or synthetic compounds. This paper deals with the preparation of bioactive formulations involving the melt processing of PLA loaded with a medicinal plant (sage) and an edible oil (coconut oil), together with an organomodifed montmorillonite nanoclay, and an assessment of the resulting structural, surface, morphological, mechanical, and biological properties of the biocomposites. By modulating the components, the prepared biocomposites show flexibility, both antioxidant and antimicrobial activity, as well as a high degree of cytocompatibility, being capable to induce the cell adherence and proliferation on their surface. Overall, the obtained results suggest that the developed PLA-based biocomposites could potentially be used as bioactive materials in medical applications.
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Affiliation(s)
- Raluca Nicoleta Darie-Niță
- “Petru Poni” Institute of Macromolecular Chemistry, 41A Gr. Ghica Voda Alley, 700487 Iasi, Romania
- Correspondence:
| | - Anamaria Irimia
- “Petru Poni” Institute of Macromolecular Chemistry, 41A Gr. Ghica Voda Alley, 700487 Iasi, Romania
| | - Florica Doroftei
- “Petru Poni” Institute of Macromolecular Chemistry, 41A Gr. Ghica Voda Alley, 700487 Iasi, Romania
| | - Laura Mihaela Stefan
- National Institute of Research and Development for Biological Sciences, 296 Splaiul Independentei, 060031 Bucharest, Romania
| | - Andrzej Iwanczuk
- Faculty of Environmental Engineering, Wroclaw University of Science and Technology, Wybrzeze Wyspiańskiego 27, 50-370 Wroclaw, Poland
| | - Agnieszka Trusz
- Faculty of Environmental Engineering, Wroclaw University of Science and Technology, Wybrzeze Wyspiańskiego 27, 50-370 Wroclaw, Poland
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De Santis D, Carbone K, Garzoli S, Laghezza Masci V, Turchetti G. Bioactivity and Chemical Profile of Rubus idaeus L. Leaves Steam-Distillation Extract. Foods 2022; 11:foods11101455. [PMID: 35627025 PMCID: PMC9140405 DOI: 10.3390/foods11101455] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2022] [Revised: 05/04/2022] [Accepted: 05/12/2022] [Indexed: 02/01/2023] Open
Abstract
The leaves of Rubus idaeus L., a by-product of the fruit food industry, are a known source of bioactive molecules, although the chemical composition has only been partially investigated. The main objective of this study was to examine the biological activities and the chemical composition of the extract of leaves of R. idaeus (RH), obtained by steam distillation (SD). The antioxidant capacity; the total phenolic content (TPC); the cytotoxic activity against tumor cell lines; and the antibacterial activity, in addition to the study of the chemical fingerprinting, carried out by Gas/Chromatography-Mass-Spectrometry (GC/MS) and Headspace (HS)-GC/MS, were established. The extract showed a strong antioxidant capacity and a modest antibacterial activity against two bacterial strains, as well as significant cytotoxic activity against tumor cell lines (Caco-2 and HL60) and being proliferative on healthy cells. Many of the GC-identified volatile molecules (1,8-cineol, β-linalool, geraniol, caryophyllene, τ-muurolol, citral, α-terpineol, 3- carene, α-terpinen-7-al, etc.) can explain most of the biological properties exhibited by the extract of R. idaeus L. The high biological activity of the RH and the high compatibility with the various matrices suggest good prospects for this extract, both in the food and cosmetic fields or in dietary supplements for improving human health.
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Affiliation(s)
- Diana De Santis
- Department for Innovation in the Biological, Agrofood and Forestry Systems, University of Tuscia Via S. C. de Lellis, 01100 Viterbo, Italy; (V.L.M.); (G.T.)
- Correspondence:
| | - Katya Carbone
- CREA Research Centre for Olive, Fruit and Citrus Crops, Via di Fioranello 52, 00134 Rome, Italy;
| | - Stefania Garzoli
- Department of Drug Chemistry and Technology, Sapienza University, Square Aldo Moro 5, 00185 Rome, Italy;
| | - Valentina Laghezza Masci
- Department for Innovation in the Biological, Agrofood and Forestry Systems, University of Tuscia Via S. C. de Lellis, 01100 Viterbo, Italy; (V.L.M.); (G.T.)
| | - Giovanni Turchetti
- Department for Innovation in the Biological, Agrofood and Forestry Systems, University of Tuscia Via S. C. de Lellis, 01100 Viterbo, Italy; (V.L.M.); (G.T.)
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Rizwan M, Durrani AZ, Ahmad T, Ahmad SS, Chaudhry M. Comparative therapeutic efficacy of procaine penicillin, Phyllanthus emblica fruit extract and Cocos nucifera oil against subclinical mastitis. Livest Sci 2021. [DOI: 10.1016/j.livsci.2021.104655] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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Nobre CB, de Sousa EO, de Lima Silva JMF, Melo Coutinho HD, da Costa JGM. Chemical composition and antibacterial activity of fixed oils of Mauritia flexuosa and Orbignya speciosa associated with aminoglycosides. Eur J Integr Med 2018. [DOI: 10.1016/j.eujim.2018.09.009] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Coelho OGL, Cândido FG, Alfenas RDCG. Dietary fat and gut microbiota: mechanisms involved in obesity control. Crit Rev Food Sci Nutr 2018; 59:3045-3053. [DOI: 10.1080/10408398.2018.1481821] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Affiliation(s)
| | - Flávia Galvão Cândido
- Departamento de Nutrição e Saúde, Universidade Federal de Viçosa, Minas Gerais, Brasil
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Hamidi SA, Tabatabaei Naeini A, Oryan A, Tabandeh MR, Tanideh N, Nazifi S. Cutaneous Wound Healing after Topical Application of Pistacia atlantica Gel Formulation in Rats. Turk J Pharm Sci 2017; 14:65-74. [PMID: 32454596 DOI: 10.4274/tjps.41713] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2015] [Accepted: 06/23/2016] [Indexed: 01/20/2023]
Abstract
Objectives This study has been undertaken to investigate the antioxidant activity of the gel formulation from Pistacia atlantica oil extraction on enzymatic antioxidants in experimental wound created in rats. Materials and Methods Under anesthesia, a square-shaped skin defect (2x2 cm) was created aseptically by surgical incision. Then, animals were randomly allocated to four groups (I- untreated controls, II- topically treated with base gel, III- topically treated with 5% gel, IV- topically treated with 10% gel). Results The results suggest that topical application of Pistacia atlantica oil gels improved reepithelialization with continuous stratum basalis and a mature granulation tissue and adnexa (hair follicles and sweat gland) compared with control and base gel groups. Treatment with 10% oil gel significantly enhanced the tensile strength, ultimate stress, yield strength and stiffness in this group compared with the control and base gel groups at 21 days post injury. The collagen fibers showed a more organized pattern and the tissue alignment was greater as compared to the control and base gel-treated groups at the same stage. Conclusion The results suggest that topical application of Pistacia atlantica oil gel improved the morphological, biochemical and biomechanical properties of experimentally-induced wound defects in rats.
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Affiliation(s)
- Seyed Ahmadreza Hamidi
- Shiraz University, Faculty Of Veterinary Medicine, Department Of Veterinary Surgery, Shiraz, Iran
| | | | - Ahmad Oryan
- Shiraz University, Faculty Of Veterinary Medicine, Department Of Pathology, Shiraz, Iran
| | - Mohammad Reza Tabandeh
- Shiraz University, Faculty Of Veterinary Medicine, Department Of Biochemistry, Shiraz, Iran
| | - Nader Tanideh
- Shiraz University Of Medical Sciences, Department Of Stem Cell And Transgenic Research Center, Shiraz, Iran
| | - Saeed Nazifi
- Kıms Collage Branch Of Rajiv Gandhi University, Student İn Dentistry, Bangalouru, India
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Peedikayil FC, Remy V, John S, Chandru TP, Sreenivasan P, Bijapur GA. Comparison of antibacterial efficacy of coconut oil and chlorhexidine on Streptococcus mutans: An in vivo study. J Int Soc Prev Community Dent 2016; 6:447-452. [PMID: 27891311 PMCID: PMC5109859 DOI: 10.4103/2231-0762.192934] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2016] [Accepted: 08/28/2016] [Indexed: 11/05/2022] Open
Abstract
AIMS Streptococcus mutans is the most common organism causing dental caries. Various chemotherapeutic agents are available that help in treating the bacteria, with each having their own merits and demerits. Recent research has shown that coconut oil has anti-inflammatory and antimicrobial action. Therefore, the present was conducted to determine the antibacterial efficacy of coconut oil and to compare it with chlorhexidine. MATERIALS AND METHODS A total of fifty female children aged 8-12 years were included in the study. Twenty five children were randomly distributed to each group, i.e., the study group (coconut oil) and the control group (chlorhexidine). The participants were asked to routinely perform oil swishing with coconut oil and chlorhexidine and rinse every day in the morning after brushing for 2-3 minutes. S. mutans in saliva and plaque were determined using a chairside method, i.e., the Dentocult SM Strip Mutans test. Patients were instructed to continue oil swishing for 30 days. S. mutans. counts in plaque and saliva on day 1, day 15, and day 30 were recorded and the results were compared using Wilcoxon matched pairs signed ranks test. RESULTS The results showed that there is a statistically significant decrease in S. mutans. count from coconut oil as well as chlorhexidine group from baseline to 30 days. The study also showed that in comparison of coconut oil and chlorhexidine there is no statistically significant change regarding the antibacterial efficacy. CONCLUSION Coconut oil is as effective as chlorhexidine in the reduction of S. mutans.
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Affiliation(s)
- Faizal C. Peedikayil
- Department of Pedodontics, Kannur Dental College, Anjarakandy, Kannur, Kerala, India
| | - Vimal Remy
- Department of Conservative Dentistry and Endodontics, Kannur Dental College, Anjarakandy, Kannur, Kerala, India
| | - Seena John
- Department of Pedodontics, Kannur Dental College, Anjarakandy, Kannur, Kerala, India
| | - T. P. Chandru
- Department of Pedodontics, Kannur Dental College, Anjarakandy, Kannur, Kerala, India
| | - Prathima Sreenivasan
- Department of Oral Medicine and Radiology, Kannur Dental College, Anjarakandy, Kannur, Kerala, India
| | - Gufran Ahmed Bijapur
- Department of Microbiology, Kannur Medical College, Anjarakandy, Kannur, Kerala, India
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Peng M, Biswas D. Short chain and polyunsaturated fatty acids in host gut health and foodborne bacterial pathogen inhibition. Crit Rev Food Sci Nutr 2016; 57:3987-4002. [DOI: 10.1080/10408398.2016.1203286] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Affiliation(s)
- Mengfei Peng
- Department of Animal and Avian Sciences, University of Maryland, College Park, Maryland, USA
- Biological Sciences Program Molecular and Cellular Biology Concentration, University of Maryland, College Park, Maryland, USA
| | - Debabrata Biswas
- Department of Animal and Avian Sciences, University of Maryland, College Park, Maryland, USA
- Biological Sciences Program Molecular and Cellular Biology Concentration, University of Maryland, College Park, Maryland, USA
- Center for Food Safety and Security Systems, University of Maryland, College Park, Maryland, USA
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Dhouioui M, Boulila A, Jemli M, Schiets F, Casabianca H, Zina MS. Fatty Acids Composition and Antibacterial Activity of Aristolochia longa L. and Bryonia dioïca Jacq. Growing Wild in Tunisia. J Oleo Sci 2016; 65:655-61. [PMID: 27430383 DOI: 10.5650/jos.ess16001] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
The composition of the fatty acids of the roots and aerial parts of Aritolochia longa (Aristolacheae) and Bryonia dioïca (Cucurbutaceae) was analyzed by gas chromatography (GC-FID) and gas chromatography-mass spectrometry (GC-MS). The oils extracted from the aerial parts of both species were rich in polyunsaturated fatty acids with the essential linolenic and linoleic acids being the most prominent compounds. Oleic and linoleic acids were the majors fatty acids in the roots of both species. Whatever the plant part analyzed and the species, the saturated fatty acids were predominantly composed of palmitic and stearic acids. The antibacterial activity, minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of the lipid extracts were determined against a panel of five bacterial strains. The results showed that the sensitivity to the lipid extracts was different for the test bacterial strains, and the susceptibility of gram positive bacteria was found to be greater than gram negative bacteria. The antibacterial activity of the root lipid extracts was particularly important against Enterococcus feacium (CMI value of 125 µg/mL; CMB values > 250 µg/mL) and Streptococcus agalactiae (CMI value of 125 µg/mL; CMB values 250 µg/mL for A. longa roots). These results indicate that A. longa and B. dioïca could be considered as good sources of essential fatty acids which can act as natural antibacterial agents.
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Affiliation(s)
- Mouna Dhouioui
- Institut National de Recherche et d'Analyse Physico-chimique (INRAP), Laboratoire des Substances Naturelles, Biotechpôle de Sidi Thabet
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Hussain A, Singh SK. Evidences for anti-mycobacterium activities of lipids and surfactants. World J Microbiol Biotechnol 2015; 32:7. [PMID: 26712622 DOI: 10.1007/s11274-015-1965-4] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2015] [Accepted: 10/14/2015] [Indexed: 10/22/2022]
Abstract
Tuberculosis is the most widespread and deadly airborne disease caused by Mycobacterium tuberculosis. The two-pronged lethal effect on the bacteria using lipids/surfactants and anti-tubercular drugs may render the miniaturization of dose owing to synergistic and tandem effect of both. The current research has been focused on screening and evaluating various lipids/surfactants possessing inherent anti-mycobacterium activity that can ferry the anti-tubercular drugs. In vitro anti-mycobacterium activity was evaluated using agar well diffusion method. Furthermore, time-concentration dependent killing and DNA/RNA content release studies were performed to correlate the findings. The exact mechanism of bacterial killing was further elucidated by electron/atomic force microscopy studies. Finally, to negate any toxicity, in vitro hemolysis and toxicity studies were performed. The study revealed that capmul MCM C-8, labrasol and acconon C-80 possessed highest in vitro anti-mycobacterium activity. Electron/atomic force microscopy results confirmed in vitro studies and verified the killing of Mycobacterium owing to the release of cytoplasmic content after cell wall fragmentation and disruption. Moreover, the least hemolysis and hundred percent survivals rate of mice using the excipients demonstrated the safety aspects of explored excipients that can ferry the anti-tubercular drugs. The present study concluded the safe, efficient and synergistic activity of the explored excipients and anti-tubercular drugs in controlling the menace of tuberculosis.
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Affiliation(s)
- Afzal Hussain
- Department of Pharmaceutical Sciences and Technology, Birla Institute of Technology, Mesra, Ranchi, Jharkhand, 835215, India
| | - Sandeep Kumar Singh
- Department of Pharmaceutical Sciences and Technology, Birla Institute of Technology, Mesra, Ranchi, Jharkhand, 835215, India.
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Xu YZ, Métris A, Stasinopoulos D, Forsythe S, Sutherland J. Effect of heat shock and recovery temperature on variability of single cell lag time of Cronobacter turicensis. Food Microbiol 2015; 45:195-204. [DOI: 10.1016/j.fm.2014.04.003] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2013] [Revised: 04/03/2014] [Accepted: 04/08/2014] [Indexed: 10/25/2022]
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Improvement of medium chain fatty acid content and antimicrobial activity of coconut oil via solid-state fermentation using a Malaysian Geotrichum candidum. BIOMED RESEARCH INTERNATIONAL 2013; 2013:954542. [PMID: 23971051 PMCID: PMC3732585 DOI: 10.1155/2013/954542] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/08/2013] [Revised: 06/19/2013] [Accepted: 06/28/2013] [Indexed: 11/17/2022]
Abstract
Coconut oil is a rich source of beneficial medium chain fatty acids (MCFAs) particularly lauric acid. In this study, the oil was modified into a value-added product using direct modification of substrate through fermentation (DIMOSFER) method. A coconut-based and coconut-oil-added solid-state cultivation using a Malaysian lipolytic Geotrichum candidum was used to convert the coconut oil into MCFAs-rich oil. Chemical characteristics of the modified coconut oils (MCOs) considering total medium chain glyceride esters were compared to those of the normal coconut oil using ELSD-RP-HPLC. Optimum amount of coconut oil hydrolysis was achieved at 29% moisture content and 10.14% oil content after 9 days of incubation, where the quantitative amounts of the modified coconut oil and MCFA were 0.330 mL/g of solid media (76.5% bioconversion) and 0.175 mL/g of solid media (53% of the MCO), respectively. MCOs demonstrated improved antibacterial activity mostly due to the presence of free lauric acid. The highest MCFAs-rich coconut oil revealed as much as 90% and 80% antibacterial activities against Staphylococcus aureus and Escherichia coli, respectively. The results of the study showed that DIMOSFER by a local lipolytic G. candidum can be used to produce MCFAs as natural, effective, and safe antimicrobial agent. The produced MCOs and MCFAs could be further applied in food and pharmaceutical industries.
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Harrison LM, Balan KV, Babu US. Dietary fatty acids and immune response to food-borne bacterial infections. Nutrients 2013; 5:1801-22. [PMID: 23698167 PMCID: PMC3708349 DOI: 10.3390/nu5051801] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2013] [Revised: 04/22/2013] [Accepted: 04/27/2013] [Indexed: 01/18/2023] Open
Abstract
Functional innate and acquired immune responses are required to protect the host from pathogenic bacterial infections. Modulation of host immune functions may have beneficial or deleterious effects on disease outcome. Different types of dietary fatty acids have been shown to have variable effects on bacterial clearance and disease outcome through suppression or activation of immune responses. Therefore, we have chosen to review research across experimental models and food sources on the effects of commonly consumed fatty acids on the most common food-borne pathogens, including Salmonella sp., Campylobacter sp., Shiga toxin-producing Escherichia coli, Shigella sp., Listeria monocytogenes, and Staphylococcus aureus. Altogether, the compilation of literature suggests that no single fatty acid is an answer for protection from all food-borne pathogens, and further research is necessary to determine the best approach to improve disease outcomes.
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Affiliation(s)
- Lisa M Harrison
- Office of Applied Research and Safety Assessment, Center for Food Safety and Applied Nutrition, Food and Drug Administration, 8301 Muirkirk Road, Laurel, MD 20708, USA.
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15
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Stochasticity in colonial growth dynamics of individual bacterial cells. Appl Environ Microbiol 2013; 79:2294-301. [PMID: 23354712 DOI: 10.1128/aem.03629-12] [Citation(s) in RCA: 85] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Conventional bacterial growth studies rely on large bacterial populations without considering the individual cells. Individual cells, however, can exhibit marked behavioral heterogeneity. Here, we present experimental observations on the colonial growth of 220 individual cells of Salmonella enterica serotype Typhimurium using time-lapse microscopy videos. We found a highly heterogeneous behavior. Some cells did not grow, showing filamentation or lysis before division. Cells that were able to grow and form microcolonies showed highly diverse growth dynamics. The quality of the videos allowed for counting the cells over time and estimating the kinetic parameters lag time (λ) and maximum specific growth rate (μmax) for each microcolony originating from a single cell. To interpret the observations, the variability of the kinetic parameters was characterized using appropriate probability distributions and introduced to a stochastic model that allows for taking into account heterogeneity using Monte Carlo simulation. The model provides stochastic growth curves demonstrating that growth of single cells or small microbial populations is a pool of events each one of which has its own probability to occur. Simulations of the model illustrated how the apparent variability in population growth gradually decreases with increasing initial population size (N(0)). For bacterial populations with N(0) of >100 cells, the variability is almost eliminated and the system seems to behave deterministically, even though the underlying law is stochastic. We also used the model to demonstrate the effect of the presence and extent of a nongrowing population fraction on the stochastic growth of bacterial populations.
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Schelin J, Wallin-Carlquist N, Cohn MT, Lindqvist R, Barker GC, Rådström P. The formation of Staphylococcus aureus enterotoxin in food environments and advances in risk assessment. Virulence 2011; 2:580-92. [PMID: 22030860 PMCID: PMC3260550 DOI: 10.4161/viru.2.6.18122] [Citation(s) in RCA: 213] [Impact Index Per Article: 16.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2011] [Revised: 09/15/2011] [Accepted: 09/16/2011] [Indexed: 01/02/2023] Open
Abstract
The recent finding that the formation of staphylococcal enterotoxins in food is very different from that in cultures of pure Staphylococcus aureus sheds new light on, and brings into question, traditional microbial risk assessment methods based on planktonic liquid cultures. In fact, most bacteria in food appear to be associated with surfaces or tissues in various ways, and interaction with other bacteria through molecular signaling is prevalent. Nowadays it is well established that there are significant differences in the behavior of bacteria in the planktonic state and immobilized bacteria found in multicellular communities. Thus, in order to improve the production of high-quality, microbiologically safe food for human consumption, in situ data on enterotoxin formation in food environments are required to complement existing knowledge on the growth and survivability of S. aureus. This review focuses on enterotoxigenic S. aureus and describes recent findings related to enterotoxin formation in food environments, and ways in which risk assessment can take into account virulence behavior. An improved understanding of how environmental factors affect the expression of enterotoxins in foods will enable us to formulate new strategies for improved food safety.
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Affiliation(s)
- Jenny Schelin
- Applied Microbiology, Department of Chemistry, Lund University, Lund, Sweden.
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Comparison of antibacterial effect of seven 1-monoglycerides on food-borne pathogens or spoilage bacteria. ACTA VET BRNO 2011. [DOI: 10.2754/avb201180010029] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
The aim of this study was to compare under the same conditionsin vitrothe inhibitory effects of seven 1-monoglycerides (MAG) containing fatty acids with a medium chain on ten strains of food-borne pathogens or spoilage gram-positive and gram-negative bacteria (Bacillus cereus, Bacillus subtilis, Enterococcus faecalis, Micrococcus luteus, Staphylococcus aureus, Citrobacter freundii, Escherichia coli, Proteus mirabilis, Salmonella entericaser.Enteritidis andPseudomonas aeruginosa) and on their growth indicatos. The inhibitory effect of MAGs (monocaprylin, monocaprin, monolaurin, monomyristin, monopalmitin, MAG of undecanoic and 10-undecenoic acids) at a concentration of 25 – 1500 mg·l-1was observed. Growth of bacteria in the presence of MAG was studied by means of optical density of bacteria for 24 h. The data were modelled through a Gompertz equation and the lag-time, the maximum specific growth rate and the maximal value reached were calculated. MAGs inhibited mainly the growth of gram-positive bacteria, which was shown by the extended lag-time, decrease in specific growth rate and decrease in cell density. Inhibitory effects of tested MAGs could be ranked from point of view of the minimum inhibitory concentration: MAG-C12:0 > MAG-C11:0 > MAG-C10:0 > MAG-C14:0 > MAG-C11:1 > MAG-C8:0 > MAG-C16:0.In vitro, no significant inhibitory effects of 1-monoglycerides, with the exception of the highest concentrations applied, on the growth of gram-negative bacteria were detected. The main contribution of this study is to compare the effects of several MAG containing fatty acids with a medium chain under the same conditions on the growth indicators of bacteria.
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Lograda T, Chaker AN, Chalchat JC, Ramdani M, Silini H, Figueredo G, Chalard P. Chemical Composition and Antimicrobial Activity of Essential Oils of Genista ulicina and G. vepres. Nat Prod Commun 2010. [DOI: 10.1177/1934578x1000500532] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023] Open
Abstract
The hydrodistilled oils from the aerial parts of Genista ulicina Spach. and G. vepres Pomel., which are endemic to Algeria, were analyzed by gas chromatography-mass spectrometry (GC-MS). In the oil of G. ulicina, 41 compounds were identified representing 90.8% of the total oil, and in G. vepres, 61 compounds representing 84.5% of the total oil. The analyses showed that the major constituents of the oils were lauric acid (14.3% – 8.5%), myristic acid (11.5% – 5%), linoleic acid (3.1% –11.7%) and palmitic acid (18.6% – 26.4%). Using a diffusion method, the oils showed significant antibacterial activities against Escherichia coli (ATCC 25922), Pseudomonas aeruginosa (ATCC 27853) and Staphylococcus aureus (ATCC 25923).
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Affiliation(s)
- Takia Lograda
- Laboratory of Natural Resource Valorization, Sciences Faculty, Ferhat Abbas University, 19000 Setif, Algeria
| | - Adel Nadjib Chaker
- Laboratory of Natural Resource Valorization, Sciences Faculty, Ferhat Abbas University, 19000 Setif, Algeria
| | - Jean Claude Chalchat
- Clermont Université, Université Blaise Pascal, BP 10448, F-63000 CLERMONT-FERRAND
| | - Messaoud Ramdani
- Laboratory of Natural Resource Valorization, Sciences Faculty, Ferhat Abbas University, 19000 Setif, Algeria
| | - Hafsa Silini
- Laboratory of Environmental Microbiology, Science Faculty, Ferhat Abbas University, 19000 Setif, Algeria
| | | | - Pierre Chalard
- Clermont Université, ENSCCF, EA 987, LCHG, BP 10448, F-63000 CLERMONT-FERRAND
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Lograda T, Chaker A, Chalard P, Ramdani M, Chalchat J, Silini H, Figueredo G. Chemical Composition and Antimicrobial Activity of Essential oil of Genista numidica Spach. and G. saharae Coss et Dur. ACTA ACUST UNITED AC 2009. [DOI: 10.3923/ajps.2009.495.499] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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Inhibitory effect of caprylic acid and mild heat on Cronobacter spp. (Enterobacter sakazakii) in reconstituted infant formula and determination of injury by flow cytometry. Int J Food Microbiol 2009; 133:113-20. [DOI: 10.1016/j.ijfoodmicro.2009.05.009] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2009] [Revised: 04/21/2009] [Accepted: 05/03/2009] [Indexed: 11/21/2022]
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