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Correa CZ, de Tavares Machado Bolonhesi IB, Lopes DD, Prates KVMC, Panagio LA, Ratuchne A, Damianovic MHRZ. Removal of organic matter and nitrogen from dairy effluents in a structured bed reactor operated with intermittent aeration. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2023; 30:91060-91073. [PMID: 37464210 DOI: 10.1007/s11356-023-28581-y] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/27/2022] [Accepted: 06/29/2023] [Indexed: 07/20/2023]
Abstract
The objective of this research was to evaluate the performance of a structured bed reactor (SBRIA), carried out with intermittent aeration (IA), in the removal of organic matter and nitrogen from dairy effluent, when run with different organic loading rates (OLR). The SBRIA was operated for 227 days, with 2:1 AI cycles (2 h with aeration on and 1 h off) and Hydraulic Retention Time (HRT) of 16 h. Three phases, with different OLR, were evaluated: phases A (1000 gCOD m-3 day-1 - 63 days), B (1400 gCOD m-3 day-1 - 94 days), and C (1800 gCOD m-3 day-1 - 70 days). The percentage of COD, NH4+-N removal, and nitrogen removal, respectively, were above 85 ± 7%, 73 ± 27%, and 83 ± 5, in all phases. There was no accumulation of the oxidized forms of nitrogen in the reactor. The kinetic test, performed to evaluate the nitrification and denitrification in the system, indicated that even in dissolved oxygen concentrations of 4.5 mg L-1, it was possible to obtain the denitrification process in the system. The results demonstrate that the reactor under study has positive characteristics to be used as an alternative for removing the removal of organic material and nitrogen in the biological treatment of dairy effluents.
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Affiliation(s)
- Camila Zoe Correa
- Department of Civil Construction, State University of Londrina, Rodovia Celso Garcia Cid, Km 380, Campus Universitario, CEP, Londrina, Parana, 86057-970, Brazil.
| | | | - Deize Dias Lopes
- Department of Civil Construction, State University of Londrina, Rodovia Celso Garcia Cid, Km 380, Campus Universitario, CEP, Londrina, Parana, 86057-970, Brazil
| | - Kátia Valéria Marques Cardoso Prates
- Department of Environmental Engineering, Federal Technological University of Paraná, Av. Dos Pioneiros 3131, Londrina, Parana, CEP 86036-370, Brazil
| | - Luciano Aparecido Panagio
- Department of Microbiology, State University of Londrina, Rodovia Celso Garcia Cid, Km 380, Campus Universitario, Londrina, Parana, CEP 86057-970, Brazil
| | - Aline Ratuchne
- Department of Microbiology, State University of Londrina, Rodovia Celso Garcia Cid, Km 380, Campus Universitario, Londrina, Parana, CEP 86057-970, Brazil
| | - Márcia Helena Rissato Zamariolli Damianovic
- Laboratory of Biological Processes, São Carlos School of Engineering, University of São Paulo (USP), 1100, João Dagnone Ave., Santa Angelina, Sao Carlos, São Paulo, 13563-120, Brazil
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Biomimetic Nanopillar Silicon Surfaces Rupture Fungal Spores. Int J Mol Sci 2023; 24:ijms24021298. [PMID: 36674814 PMCID: PMC9864238 DOI: 10.3390/ijms24021298] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2022] [Revised: 12/17/2022] [Accepted: 12/28/2022] [Indexed: 01/11/2023] Open
Abstract
The mechano-bactericidal action of nanostructured surfaces is well-documented; however, synthetic nanostructured surfaces have not yet been explored for their antifungal properties toward filamentous fungal species. In this study, we developed a biomimetic nanostructured surface inspired by dragonfly wings. A high-aspect-ratio nanopillar topography was created on silicon (nano-Si) surfaces using inductively coupled plasma reactive ion etching (ICP RIE). To mimic the superhydrophobic nature of insect wings, the nano-Si was further functionalised with trichloro(1H,1H,2H,2H-perfluorooctyl)silane (PFTS). The viability of Aspergillus brasiliensis spores, in contact with either hydrophobic or hydrophilic nano-Si surfaces, was determined using a combination of standard microbiological assays, confocal laser scanning microscopy (CLSM), and focused ion beam scanning electron microscopy (FIB-SEM). Results indicated the breakdown of the fungal spore membrane upon contact with the hydrophilic nano-Si surfaces. By contrast, hydrophobised nano-Si surfaces prevented the initial attachment of the fungal conidia. Hydrophilic nano-Si surfaces exhibited both antifungal and fungicidal properties toward attached A. brasisiensis spores via a 4-fold reduction of attached spores and approximately 9-fold reduction of viable conidia from initial solution after 24 h compared to their planar Si counterparts. Thus, we reveal, for the first time, the physical rupturing of attaching fungal spores by biomimetic hydrophilic nanostructured surfaces.
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Hussein NA, Soliman ZS, Edrees MF. Oral microbiota associated with gingiva of healthy, gingivitis and periodontitis cases. Microb Pathog 2022; 171:105724. [PMID: 35988883 DOI: 10.1016/j.micpath.2022.105724] [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: 03/17/2022] [Revised: 08/04/2022] [Accepted: 08/12/2022] [Indexed: 11/26/2022]
Abstract
Oral microbes coexist with each other in a symbiotic relationship or as commensals in healthy body. Teeth and oral cavity harbor diverse community of fungi and bacteria. This study focused on bacterial and fungal component of gingiva, where the last occupy little attention. In addition to study the antimicrobial activity of toothpastes, mouth washes and natural oils against microorganisms. Sixty swabs from outer surfaces of gingiva in healthy persons, as well as patients complaining of gingivitis and periodontitis were collected for fungal and bacterial analyses. Sensitivity of the isolated microorganisms to some pharmaceutical preparations and natural oils was also performed. Ten fungal and 9 bacterial species were identified. There is a highly significant variation in the frequency of Klebsiella pneumonia among healthy, gingivitis and periodontitis. Also, Candida tropicalis and cocci bacteria showed significant diversity among the three tested groups. Among pharmaceutical preparations (toothpastes and mouth washes) and natural oils, Paradontax, Hexitol and clove oil showed the best antimicrobial activity against tested fungal and bacterial strains. Although, minimum inhibition concentrations (MICs) of clove oil were high compared to Paradontax and Hexitol, nevertheless, it is highly recommended as both antifungal and antibacterial agent against oral pathogenic microorganisms, because it is a natural compound and nearly devoid of side effects.
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Affiliation(s)
- Nemmat A Hussein
- Botany and Microbiology Department, Faculty of Science, Assiut University, P.O. Box 71526, Assiut, Egypt; Assiut University Moubasher Mycological Centre (AUMC), Assiut University, P.O. Box 71526, Assiut, Egypt.
| | - Zeinab S Soliman
- Assiut University Moubasher Mycological Centre (AUMC), Assiut University, P.O. Box 71526, Assiut, Egypt
| | - Mohamed F Edrees
- Oral Medicine and Periodontology Department, Faculty of Dentistry, AL-Azhar University, Assiut Branch, Egypt
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Microbiological Evaluation of Water Used in Dental Units. WATER 2022. [DOI: 10.3390/w14060915] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
In modern dentistry, dental units are used for the treatment of patients’ teeth, and they need water to operate. Water circulates in a closed vessel system and finally reaches the mucous membranes of the patient as well as the dentist themselves. Therefore, the microbiological safety of this water should be a priority for physicians. This study aims to identify and determine the microbial count, expressed in CFU/mL, in water samples from various parts of the dental unit that are in direct contact with the patient. Thirty-four dental units located in dentistry rooms were analysed. The dentistry rooms were divided into three categories: surgical, conservative, and periodontal. It was found that in surgical rooms, the bacterial count was 1464.76 CFU/mL, and the most common bacterium was Staphylococcus pasteuri—23.88% of the total bacteria identified. In dentistry rooms where conservative treatments were applied, the average bacterial concentration was 8208.35 CFU/mL, and the most common bacterium was Ralsonia pickettii (26.31%). The periodontal rooms were also dominated by R. pickettii (45.13%), and the average bacterial concentration was 8743.08 CFU/mL. Fungi were also detected. Rhodotorula spp., Alternaria spp., and Candida parapsilosis were found to be the most common bacteria which are potentially harmful. This study indicates the need for effective decontamination of the water that is used in dental units and for constant monitoring of the level of contaminants present in the closed vessel system.
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Castellano Realpe OJ, Gutiérrez JC, Sierra DA, Pazmiño Martínez LA, Prado Palacios YY, Echeverría G, de Waard JH. Dental Unit Waterlines in Quito and Caracas Contaminated with Nontuberculous Mycobacteria: A Potential Health Risk in Dental Practice. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2020; 17:E2348. [PMID: 32244267 PMCID: PMC7177417 DOI: 10.3390/ijerph17072348] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/20/2020] [Revised: 02/16/2020] [Accepted: 02/20/2020] [Indexed: 11/17/2022]
Abstract
Three cases of severe odontogenic infections due to nontuberculous mycobacteria (NTM) in Venezuela that were directly associated with dental procedures and the finding of dental unit waterlines (DUWLs) in dental offices that were colonized with mycobacteria species was the reason for assessing the water quality of DUWLs in dental offices in two capital cities in South America, namely, Quito and Caracas. The main water supplies and the water from 143 DUWLs in both cities were sampled and especially checked for contamination with NTM. To measure the overall bacteriological quality of the water also the presence of heterotrophic bacteria, coliform bacteria, and Pseudomonas was determined. Results showed that respectively 3% and 56% of the DUWLs in Quito and Caracas yielded NTM species (up to 1000 colony-forming units (CFU)/mL). Furthermore, high and unacceptable total viable counts of heterotrophic bacteria and/or coliform bacteria and Pseudomonas were detected in 73% of the samples. We conclude that, in both cities, the water in the majority of DUWLs was contaminated with NTM and other potential pathogens, presenting a risk to human health. The detection of NTM in DUWL water with acceptable heterotrophic bacteria counts shows the need to include NTM in water quality testing. Mycobacteria are more resistant to disinfection procedures than other types of vegetative bacteria, and most testing protocols for DUWLs do not assess mycobacteria and thus do not guarantee risk-free water.
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Affiliation(s)
| | - Johanna C. Gutiérrez
- Facultad de Medicina. Escuela de Bioanálisis, Universidad Central de Venezuela, 1053 Caracas, Venezuela
- Instituto de Biomedicina “Dr. Jacinto Convit”, Universidad Central de Venezuela, 1010 Caracas, Venezuela
| | - Deisy A. Sierra
- Facultad de Medicina. Escuela de Bioanálisis, Universidad Central de Venezuela, 1053 Caracas, Venezuela
- Instituto de Biomedicina “Dr. Jacinto Convit”, Universidad Central de Venezuela, 1010 Caracas, Venezuela
| | | | - Yrneh Y. Prado Palacios
- Instituto de Biomedicina “Dr. Jacinto Convit”, Universidad Central de Venezuela, 1010 Caracas, Venezuela
| | - Gustavo Echeverría
- Instituto de Investigación en Salud Pública y Zoonosis CIZ, Universidad Central del Ecuador, 170521 Quito, Ecuador
| | - Jacobus H. de Waard
- Instituto de Biomedicina “Dr. Jacinto Convit”, Universidad Central de Venezuela, 1010 Caracas, Venezuela
- One Health Research Group, Facultad de Ciencias de la Salud, Universidad De Las Américas, 170504 Quito, Ecuador
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Abstract
Rhodotorula spp. belong to the basidiomyceteous fungi. They are widespread in the environment. Transmission to humans occur mainly through air and food. Intestinal colonization is rather common, but an overgrowth is normally suppressed, since their optimal growth temperature is exceeded in the body. A massive presence in the gut indicates a disturbance of the balance of the microbial flora due to different causes. One particular reason will be the treatment with azoles because this will create an advantage for these azole resistant fungi. First of all, the finding of increased numbers of Rhodotorula in stool specimen is not alarming. In contrast, the colonized human will profit from such a situation since these fungi produce a lot of useful nutrients such as proteins, lipids, folate, and carotinoids. Furthermore, a probiotic effect due to regulation of multiplication of pathogenic bacteria and by neutralizing or destroying their toxins can be anticipated. On the other hand, their massive presence may increase the risk of fungemia and ensuing organ infections especially when the host defense system is hampered. Indeed, Rhodotorula spp. range among the emerging fungal pathogens in the compromised host. However, it can be doubted whether all these opportunistic infections reported originate primarily from the gut.
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