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Torres JL, Faulhaber JR. Triple-valve endocarditis due to Lysinibacillus sphaericus infection. IDCases 2023; 33:e01856. [PMID: 37577048 PMCID: PMC10415700 DOI: 10.1016/j.idcr.2023.e01856] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2023] [Revised: 07/20/2023] [Accepted: 07/21/2023] [Indexed: 08/15/2023] Open
Abstract
Lysinibacillus sphaericus is an environmental organism often considered a contaminant when isolated from patient specimens due to its rare association with human disease. Here we report a case of triple valve endocarditis caused by L. sphaericus infection. To the authors' knowledge, this is the first documented case of endocarditis caused by this bacterium.
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Affiliation(s)
- Jordan L. Torres
- Department of Infectious Disease, Virginia Tech Carilion School of Medicine, 213 McClanahan St SW, Roanoke, VA, 24014, USA
| | - Jason R. Faulhaber
- Department of Infectious Disease, Virginia Tech Carilion School of Medicine, 213 McClanahan St SW, Roanoke, VA, 24014, USA
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Siew SW, Musa SM, Sabri N'A, Farida Asras MF, Ahmad HF. Evaluation of pre-treated healthcare wastes during COVID-19 pandemic reveals pathogenic microbiota, antibiotics residues, and antibiotic resistance genes against beta-lactams. ENVIRONMENTAL RESEARCH 2023; 219:115139. [PMID: 36565841 PMCID: PMC9771581 DOI: 10.1016/j.envres.2022.115139] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/03/2022] [Revised: 11/25/2022] [Accepted: 12/20/2022] [Indexed: 06/17/2023]
Abstract
The disposal of healthcare waste without prior elimination of pathogens and hazardous contaminants has negative effects on the environment and public health. This study aimed to profile the complete microbial community and correlate it with the antibiotic compounds identified in microwave pre-treated healthcare wastes collected from three different waste operators in Peninsular Malaysia. The bacterial and fungal compositions were determined via amplicon sequencing by targeting the full-length 16S rRNA gene and partial 18S with full-length ITS1-ITS2 regions, respectively. The antibiotic compounds were characterized using high-throughput spectrometry. There was significant variation in bacterial and fungal composition in three groups of samples, with alpha- (p-value = 0.04) and beta-diversity (p-values <0.006 and < 0.002), respectively. FC samples were found to acquire more pathogenic microorganisms than FA and FV samples. Paenibacillus and unclassified Bacilli genera were shared among three groups of samples, meanwhile, antibiotic-resistant bacteria Proteus mirabilis, Enterococcus faecium, and Enterococcus faecalis were found in modest quantities. A total of 19 antibiotic compounds were discovered and linked with the microbial abundance detected in the healthcare waste samples. The principal component analysis demonstrated a positive antibiotic-bacteria correlation for genera Pseudomonas, Aerococcus, Comamonas, and Vagococcus, while the other bacteria were negatively linked with antibiotics. Nevertheless, deep bioinformatic analysis confirmed the presence of blaTEM-1 and penP which are associated with the production of class A beta-lactamase and beta-lactam resistance pathways. Microorganisms and contaminants, which serve as putative indicators in healthcare waste treatment evaluation revealed the ineffectiveness of microbial inactivation using the microwave sterilization method. Our findings suggested that the occurrence of clinically relevant microorganisms, antibiotic contaminants, and associated antibiotic resistance genes (ARGs) represent environmental and human health hazards when released into landfills via ARGs transmission.
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Affiliation(s)
- Shing Wei Siew
- Faculty of Industrial Sciences and Technology, Universiti Malaysia Pahang, Lebuhraya Tun Razak, 26300, Gambang, Pahang, Malaysia.
| | - Siti Munirah Musa
- Faculty of Industrial Sciences and Technology, Universiti Malaysia Pahang, Lebuhraya Tun Razak, 26300, Gambang, Pahang, Malaysia.
| | - Nurul 'Azyyati Sabri
- Faculty of Industrial Sciences and Technology, Universiti Malaysia Pahang, Lebuhraya Tun Razak, 26300, Gambang, Pahang, Malaysia; Group of Environment, Microbiology and Bioprocessing (GERMS), Lebuhraya Tun Razak, 26300, Gambang, Pahang, Malaysia.
| | - Mohd Fazli Farida Asras
- Faculty of Industrial Sciences and Technology, Universiti Malaysia Pahang, Lebuhraya Tun Razak, 26300, Gambang, Pahang, Malaysia; Group of Environment, Microbiology and Bioprocessing (GERMS), Lebuhraya Tun Razak, 26300, Gambang, Pahang, Malaysia.
| | - Hajar Fauzan Ahmad
- Faculty of Industrial Sciences and Technology, Universiti Malaysia Pahang, Lebuhraya Tun Razak, 26300, Gambang, Pahang, Malaysia; Group of Environment, Microbiology and Bioprocessing (GERMS), Lebuhraya Tun Razak, 26300, Gambang, Pahang, Malaysia.
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Cyprowski M, Ławniczek-Wałczyk A, Stobnicka-Kupiec A, Gołofit-Szymczak M, Górny RL. Across-Shift Changes in Viable Nasal Bacteria among Waste-Incineration Plant Workers-A Pilot Study. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2022; 19:ijerph19158984. [PMID: 35897354 PMCID: PMC9331216 DOI: 10.3390/ijerph19158984] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/14/2022] [Revised: 07/19/2022] [Accepted: 07/20/2022] [Indexed: 11/16/2022]
Abstract
The aim of this pilot study was to assess the time-related changes in viable nasal bacteria concentrations among waste-incineration plant (WIP) workers compared to a group of office building (OB) workers outside the plant. In total, 20 volunteers participated in the study, including 14 WIP and 6 OB workers. WIP workers were divided into two sub-groups: supervisory staff (SVS) and maintenance and repair workers (MRW). Nasal swabs were collected before and after the morning work shift. Airborne bacteria were sampled with a six-stage impactor to assess the bioaerosol size distribution. The analysis showed that a significant, almost three-fold increase in nasal bacterial concentration was found only among WIP workers, and this referred mainly to anaerobic species. The load of anaerobic bacteria at the beginning of work was 12,988 CFU/mL, and after work shift 36,979 CFU/mL (p < 0.01). Significant increases in microbial concentrations was found only in the MRW subgroup, among non-smoking workers only. The results showed increased bacterial concentration in WIP nasal samples for as many as 12 bacterial species, including, e.g., Streptococcus constellatus, Peptostreptococcus spp., E. coli, and P. mirabilis. These preliminary data confirmed that the nasal swab method was helpful for assessment of the workers’ real-time exposure to airborne bacteria.
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Baghani AN, Golbaz S, Ebrahimzadeh G, Guzman MI, Delikhoon M, Rastani MJ, Barkhordari A, Nabizadeh R. Characteristics and assessing biological risks of airborne bacteria in waste sorting plant. ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 2022; 232:113272. [PMID: 35121253 DOI: 10.1016/j.ecoenv.2022.113272] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/15/2021] [Revised: 01/14/2022] [Accepted: 01/28/2022] [Indexed: 06/14/2023]
Abstract
Examining the concentration and types of airborne bacteria in waste paper and cardboard sorting plants (WPCSP) is an urgent matter to inform policy makers about the health impacts on exposed workers. Herein, we collected 20 samples at 9 points of a WPCSP every 6 winter days, and found that the most abundant airborne bacteria were positively and negatively correlated to relative humidity and temperature, respectively. The most abundant airborne bacteria (in units of CFU m-3) were: Staphylococcus sp. (72.4) > Micrococcus sp. (52.2) > Bacillus sp. (30.3) > Enterococcus sp. (24.0) > Serratia marcescens (20.1) > E. coli (19.1) > Pseudomonas sp. (16.0) > Nocardia sp. (1.9). The lifetime average daily dose (LADD) for the inhalation and dermal routes for the intake of airborne bacteria ranged from 3.7 × 10-3 ≤ LADDInhalation ≤ 2.07 × 101 CFU (kg d)-1 and 4.75 × 10-6 ≤ LADDDermal ≤ 1.64 × 10-5 CFU (kg d)-1, respectively. Based on a sensitivity analysis (SA), the concentration of airborne bacteria (C) and the exposure duration (ED) had the most effect on the LADDInhalation and LADDDermal for all sampling locations. Although the Hazard Quotient of airborne bacteria was HQ < 1, an acceptable level, the indoor/outdoor ratio (1.5 ≤ I/O ≤ 6.6) of airborne bacteria typically exceeded the threshold value (I/O > 2), indicating worker's exposure to an infected environment. Therefore, in the absence of sufficient natural ventilation the indoor ambient conditions of the WPCSP studied should be controlled by supplying mechanical ventilation.
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Affiliation(s)
- Abbas Norouzian Baghani
- Department of Environmental Health Engineering, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran.
| | - Somayeh Golbaz
- Department of Environmental Health Engineering, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran
| | - Gholamreza Ebrahimzadeh
- Department of Environmental Health Engineering, Faculty of Health, Zabol University of Medical Sciences, Zabol, Iran
| | - Marcelo I Guzman
- Department of Chemistry, University of Kentucky, Lexington, KY 40506, USA.
| | - Mahdieh Delikhoon
- Department of Occupational Health Engineering, School of Public Health, Isfahan University of Medical Sciences, Isfahan, Iran.
| | - Mehdi Jamshidi Rastani
- Department of Occupational Health Engineering, School of Public Health, Shahroud University of Medical Sciences, Shahroud, Iran
| | - Abdullah Barkhordari
- Department of Occupational Health Engineering, School of Public Health, Shahroud University of Medical Sciences, Shahroud, Iran; Environmental and Occupational Health Research Center, Shahroud University of Medical Sciences, Shahroud, Iran
| | - Ramin Nabizadeh
- Department of Environmental Health Engineering, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran; Center for Air Pollution Research (CAPR), Institute for Environmental Research (IER), Tehran University of Medical Sciences, Tehran, Iran.
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Ferronato N, Ragazzi M, Torrez Elias MS, Gorritty Portillo MA, Guisbert Lizarazu EG, Torretta V. Application of healthcare waste indicators for assessing infectious waste management in Bolivia. WASTE MANAGEMENT & RESEARCH : THE JOURNAL OF THE INTERNATIONAL SOLID WASTES AND PUBLIC CLEANSING ASSOCIATION, ISWA 2020; 38:4-18. [PMID: 31665977 DOI: 10.1177/0734242x19883690] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
In the developing world, healthcare waste management is a human health and environmental burden that should be solved for improving sustainability. Solutions should be introduced in the short term, concerning management, planning, financial assistance and expertise. The paper introduces an indicator set for assessing healthcare waste management in developing cities, implemented in La Paz (Bolivia) as a case study. The objective is to suggest an integrated management tool as a first assessment technique to identify the prevailing problems with a healthcare waste management system. Results suggest that, in La Paz, the application of such indicators is useful for evaluating which priorities should be addressed for improving the healthcare waste management system. The tool was applied for introducing a study necessary for the application of new management plans, especially concerning healthcare waste treatment. The method can be replicated in other contexts worldwide, with a focus on the developing world, for comparing cities, management solutions and improvements carried out along the years. The approach is of interest for boosting sustainability and human health, improving the awareness of the actors and policy-makers involved in waste management.
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Affiliation(s)
- Navarro Ferronato
- Department of Theoretical and Applied Sciences, University of Insubria, Italy
| | - Marco Ragazzi
- Department of Civil, Environmental and Mechanical Engineering, University of Trento, Italy
| | | | | | | | - Vincenzo Torretta
- Department of Theoretical and Applied Sciences, University of Insubria, Italy
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Waste Mismanagement in Developing Countries: A Review of Global Issues. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2019; 16:ijerph16061060. [PMID: 30909625 PMCID: PMC6466021 DOI: 10.3390/ijerph16061060] [Citation(s) in RCA: 370] [Impact Index Per Article: 74.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/06/2019] [Revised: 03/20/2019] [Accepted: 03/22/2019] [Indexed: 12/16/2022]
Abstract
Environmental contamination due to solid waste mismanagement is a global issue. Open dumping and open burning are the main implemented waste treatment and final disposal systems, mainly visible in low-income countries. This paper reviews the main impacts due to waste mismanagement in developing countries, focusing on environmental contamination and social issues. The activity of the informal sector in developing cities was also reviewed, focusing on the main health risks due to waste scavenging. Results reported that the environmental impacts are pervasive worldwide: marine litter, air, soil and water contamination, and the direct interaction of waste pickers with hazardous waste are the most important issues. Many reviews were published in the scientific literature about specific waste streams, in order to quantify its effect on the environment. This narrative literature review assessed global issues due to different waste fractions showing how several sources of pollution are affecting the environment, population health, and sustainable development. The results and case studies presented can be of reference for scholars and stakeholders for quantifying the comprehensive impacts and for planning integrated solid waste collection and treatment systems, for improving sustainability at a global level.
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Mhady AIA, Awad MA, Al-Aghah MR, El-Nahhal YZ. Assessment of Medical Waste Management in El Shifa and Al Aqsa Hospitals-Gaza Strip. Health (London) 2019. [DOI: 10.4236/health.2019.118081] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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Assessment of Healthcare Waste Management Paradigms and Its Suitable Treatment Alternative: A Case Study. JOURNAL OF ENVIRONMENTAL AND PUBLIC HEALTH 2018; 2018:6879751. [PMID: 30151013 PMCID: PMC6087569 DOI: 10.1155/2018/6879751] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/11/2017] [Revised: 11/15/2017] [Accepted: 01/11/2018] [Indexed: 12/13/2022]
Abstract
The management and treatment of healthcare waste (HCW) are of great concern owing to its potential hazard to human health and the environment, particularly in developing countries. Nowadays, various technological alternatives are gaining momentum as efficient and favorable waste management options across the world. However, selecting a suitable technology as well as an effective waste management approach for the treatment of HCW is still a challenging task for the municipal authorities. This study renders a comprehensive analysis of healthcare waste management (HCWM) practices and the technological options for its better management through a case study in Khulna, the southwestern division of Bangladesh. A number of healthcare establishments (HCEs) in the study area were selected and a questionnaire survey, as well as field investigations, was performed to find out the present status of HCWM and its limitations. An assessment of different technological alternatives was also carried out using Sustainability Assessment of Technologies (SAT) methodology which could pave the way for treating hazardous waste more efficiently in the Khulna metropolitan area. The study revealed that the overall HCW generation rate and hazardous HCW generation rate in Khulna city were 0.90 kg bed-1 day-1 and 0.18 kg bed-1 day-1, respectively. Assessment of management system revealed that 56% (n = 38) of workers did not receive any form of training in the handling of hazardous waste. Around 54% (n = 47) of them did not use any safety equipment or clothing. It has been found from the study that, among different technological alternatives based on the final score, incineration was the most suitable option for the treatment of hazardous waste in Khulna. Finally, some guidelines have been put forward to improve its existing management practices.
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Tagliaferri TL, Vieira CD, de Carvalho MAR, Ladeira LCD, Magalhães PP, de Macêdo Farias L, Dos Santos SG. Phenotypic and genotypic characterization of clinically relevant bacteria isolated from dental waste and waste workers' hands, mucosas and coats. Lett Appl Microbiol 2017; 65:306-312. [PMID: 28712134 DOI: 10.1111/lam.12775] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2017] [Revised: 07/05/2017] [Accepted: 07/06/2017] [Indexed: 12/14/2022]
Abstract
Infectious wastes are potential sources of pathogenic micro-organisms, which may represent a risk to the professionals who manage them. In this study, we aimed to characterize the infectious bacteria present in dental waste and waste workers. The dental waste produced over 24 h was collected and waste workers were sampled by swabbing. Isolate resistance profiles were characterized by Vitek® and PCR and biofilm formation by Congo Red agar, string test and microtitre assay. To assess similarity between the waste and the workers' samples, a random amplified polymorphic DNA test was used. Twenty-eight bacteria were identified as clinically relevant. The most frequent gene was blaTEM present in five Gram-negative micro-organisms, and one blaSHV in Klebsiella pneumoniae. All Pseudomonas aeruginosa were positive to extracellular polymeric substances formation, except one isolated from a worker. Klebsiella pneumoniae had negative results for the string test. Pseudomonas aeruginosa showed better adherence at 25°C after 48 h of incubation and K. pneumonia had the best biofilm formation at the same temperature, after 24 h. The similarity between P. aeruginosa recovered from dental waste and from workers was low, however, it is important to note that a pathogen was found on a worker's hands and that improvements in biosafety are required. SIGNIFICANCE AND IMPACT OF THE STUDY Infectious dental waste can contain clinically relevant bacteria with important resistance and biofilm profiles. These micro-organisms could be transmitted to waste workers, other professionals and patients if the principles of biosafety measures are neglected. To our knowledge, no study has ever evaluated the microbial characterization and the potential contamination risk of dental infectious waste and waste handlers. The presence of clinically relevant bacteria in the hands and nasal mucosa of waste workers highlights the need for studies in this field to clarify the risk of these pathogens in dental healthcare services, and to stress the need for an efficient waste management.
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Affiliation(s)
- T L Tagliaferri
- Department of Microbiology, Institute of Biological Sciences, Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, Brazil
| | - C D Vieira
- Department of Microbiology, Institute of Biological Sciences, Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, Brazil
| | - M A R de Carvalho
- Department of Microbiology, Institute of Biological Sciences, Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, Brazil
| | - L C D Ladeira
- Nuclear Technology Development Center (CDTN), Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, Brazil
| | - P P Magalhães
- Department of Microbiology, Institute of Biological Sciences, Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, Brazil
| | - L de Macêdo Farias
- Department of Microbiology, Institute of Biological Sciences, Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, Brazil
| | - S G Dos Santos
- Department of Microbiology, Institute of Biological Sciences, Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, Brazil
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Mwaikono KS, Maina S, Sebastian A, Schilling M, Kapur V, Gwakisa P. High-throughput sequencing of 16S rRNA Gene Reveals Substantial Bacterial Diversity on the Municipal Dumpsite. BMC Microbiol 2016; 16:145. [PMID: 27400733 PMCID: PMC4940873 DOI: 10.1186/s12866-016-0758-8] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2015] [Accepted: 07/02/2016] [Indexed: 12/13/2022] Open
Abstract
Background Multiple types of solid waste in developing countries is disposed of together in dumpsites where there is interaction between humans, animals and the bacteria in the waste. To study the bacteria at the dumpsite and the associated risks, previous studies have focused on culturable, leaving behind a great number of unculturable bacteria. This study focuses on a more comprehensive approach to study bacteria at the dumpsite. Since the site comprised of unsorted wastes, a qualitative survey was first performed to identify the variety of solid waste as this has influence on the microbial composition. Thus, domestic (Dom), biomedical (Biom), river sludge (Riv), and fecal material of pigs scavenging on the dumpsite (FecD) were sampled. Total DNA was extracted from 78 samples and the v4-16S rRNA amplicons was characterized using an Illumina MiSeq platform. Results A total of 8,469,294 sequences passed quality control. Catchall analysis predicted a mean of 8243 species per sample. Diversity was high with an average InvSimpson index of 44.21 ± 1.44. A total of 35 phyla were detected and the predominant were Firmicutes (38 %), Proteobacteria (35 %), Bacteroidetes (13 %) and Actinobacteria (3 %). Overall 76,862 OTUs were detected, however, only 20 % were found more than 10 times. The predominant OTUs were Acinetobacter (12.1 %), Clostridium sensu stricto (4.8 %), Proteinclasticum and Lactobacillus both at (3.4 %), Enterococcus (2.9 %) and Escherichia/Shigella (1.7 %). Indicator analysis (P ≤ 0.05, indicator value ≥ 70) shows that Halomonas, Idiomarina, Tisierella and Proteiniclasticum were associated with Biom; Enterococcus, Bifidobacteria, and Clostridium sensu stricto with FecD and Flavobacteria, Lysobacter and Commamonas to Riv. Acinetobacter and Clostridium sensu stricto were found in 62 % and 49 % of all samples, respectively, at the relative abundance of 1 %. None of OTUs was found across all samples. Conclusions This study provides a comprehensive report on the abundance and diversity bacteria in municipal dumpsite. The species richness reported here shows the complexity of this man-made ecosystem and calls for further research to assess for a link between human diseases and the dumpsite. This would provide insight into proper disposal of the waste, as well as, limit the risks to human health associated with the dumpsite. Electronic supplementary material The online version of this article (doi:10.1186/s12866-016-0758-8) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Kilaza Samson Mwaikono
- Department of Science and Laboratory Technology, Dar es Salaam Institute of Technology, Dar es Salaam, Tanzania. .,School of Life Sciences and Bioengineering, The Nelson Mandela African Institution of Science and Technology, P.O. Box 447, Arusha, Tanzania.
| | - Solomon Maina
- BecA-ILRI Hub International Livestock Research Institute, P. O. Box 30709, Nairobi, Kenya
| | - Aswathy Sebastian
- Departments of Biochemistry and Molecular Biology, W238A Millennium Science Complex, Penn State University, University Park, PA, 16802, USA
| | - Megan Schilling
- Huck Institutes of Life Sciences, Molecular Cellular and Integrative Biosciences, the Pennsylvania State University, 204 Wartik Laboratories, University Park, PA, 16802, USA
| | - Vivek Kapur
- School of Life Sciences and Bioengineering, The Nelson Mandela African Institution of Science and Technology, P.O. Box 447, Arusha, Tanzania.,Huck Institutes of Life Sciences, Molecular Cellular and Integrative Biosciences, the Pennsylvania State University, 204 Wartik Laboratories, University Park, PA, 16802, USA
| | - Paul Gwakisa
- School of Life Sciences and Bioengineering, The Nelson Mandela African Institution of Science and Technology, P.O. Box 447, Arusha, Tanzania.,Genome Sciences Centre, Faculty of Veterinary Medicine, Sokoine University of Agriculture, Morogoro, Tanzania
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Hossain MS, Nik Ab Rahman NN, Balakrishnan V, Alkarkhi AFM, Ahmad Rajion Z, Ab Kadir MO. Optimizing supercritical carbon dioxide in the inactivation of bacteria in clinical solid waste by using response surface methodology. WASTE MANAGEMENT (NEW YORK, N.Y.) 2015; 38:462-473. [PMID: 25636860 DOI: 10.1016/j.wasman.2015.01.003] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/10/2014] [Revised: 12/04/2014] [Accepted: 01/02/2015] [Indexed: 06/04/2023]
Abstract
Clinical solid waste (CSW) poses a challenge to health care facilities because of the presence of pathogenic microorganisms, leading to concerns in the effective sterilization of the CSW for safe handling and elimination of infectious disease transmission. In the present study, supercritical carbon dioxide (SC-CO2) was applied to inactivate gram-positive Staphylococcus aureus, Enterococcus faecalis, Bacillus subtilis, and gram-negative Escherichia coli in CSW. The effects of SC-CO2 sterilization parameters such as pressure, temperature, and time were investigated and optimized by response surface methodology (RSM). Results showed that the data were adequately fitted into the second-order polynomial model. The linear quadratic terms and interaction between pressure and temperature had significant effects on the inactivation of S. aureus, E. coli, E. faecalis, and B. subtilis in CSW. Optimum conditions for the complete inactivation of bacteria within the experimental range of the studied variables were 20 MPa, 60 °C, and 60 min. The SC-CO2-treated bacterial cells, observed under a scanning electron microscope, showed morphological changes, including cell breakage and dislodged cell walls, which could have caused the inactivation. This espouses the inference that SC-CO2 exerts strong inactivating effects on the bacteria present in CSW, and has the potential to be used in CSW management for the safe handling and recycling-reuse of CSW materials.
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Affiliation(s)
- Md Sohrab Hossain
- Department of Environmental Technology, School of Industrial Technology, Universiti Sains Malaysia, 11800 Penang, Malaysia
| | | | - Venugopal Balakrishnan
- Institute for Research in Molecular Medicine, Universiti Sains Malaysia, 11800 Penang, Malaysia
| | - Abbas F M Alkarkhi
- Department of Environmental Technology, School of Industrial Technology, Universiti Sains Malaysia, 11800 Penang, Malaysia
| | - Zainul Ahmad Rajion
- School of Dental Science, Universiti Sains Malaysia, 16150 Kubang Kerian, Kelantan, Malaysia
| | - Mohd Omar Ab Kadir
- Department of Environmental Technology, School of Industrial Technology, Universiti Sains Malaysia, 11800 Penang, Malaysia.
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Oosthuysen J, Potgieter E, Fossey A. Compliance with infection prevention and control in oral health-care facilities: a global perspective. Int Dent J 2014; 64:297-311. [PMID: 25244364 DOI: 10.1111/idj.12134] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
Many publications are available on the topic of compliance with infection prevention and control in oral health-care facilities all over the world. The approaches of developing and developed countries show wide variation, but the principles of infection prevention and control are the same globally. This study is a systematic review and global perspective of the available literature on infection prevention and control in oral health-care facilities. Nine focus areas on compliance with infection-control measures were investigated: knowledge of infectious occupational hazards; personal hygiene and care of hands; correct application of personal protective equipment; use of environmental barriers and disposable items; sterilisation (recirculation) of instruments and handpieces; disinfection (surfaces) and housekeeping; management of waste disposal; quality control of dental unit waterlines, biofilms and water; and some special considerations. Various international studies from developed countries have reported highly scientific evidence-based information. In developed countries, the resources for infection prevention and control are freely available, which is not the case in developing countries. The studies in developing countries also indicate serious shortcomings with regard to infection prevention and control knowledge and education in oral health-care facilities. This review highlights the fact that availability of resources will always be a challenge, but more so in developing countries. This presents unique challenges and the opportunity for innovative thinking to promote infection prevention and control.
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Affiliation(s)
- Jeanné Oosthuysen
- Department of Life Sciences, Central University of Technology, Free State, Bloemfontein, South Africa
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Occurrence of an environmental Acinetobacter baumannii strain similar to a clinical isolate in paleosol from Croatia. Appl Environ Microbiol 2014; 80:2860-6. [PMID: 24584245 DOI: 10.1128/aem.00312-14] [Citation(s) in RCA: 52] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Over the past decade, bacteria of the genus Acinetobacter have emerged as a leading cause of hospital-acquired infections. Outbreaks of Acinetobacter infections are considered to be caused exclusively by contamination and transmission in hospital environments. The natural habitats of clinically important multiresistant Acinetobacter spp. remain to be defined. In this paper, we report an incidental finding of a viable multidrug-resistant strain of Acinetobacter baumannii, related to clinical isolates, in acid paleosol from Croatia. The environmental isolate of A. baumannii showed 87% similarity to a clinical isolate originating from a hospital in this geographic area and was resistant to gentamicin, trimethoprim-sulfamethoxazole, ciprofloxacin, and levofloxacin. In paleosol, the isolate was able to survive a low pH (3.37), desiccation, and a high temperature (50°C). The probable source of A. baumannii in paleosol is illegally disposed waste of external origin situated in the abandoned quarry near the sampling site. The bacteria could have been leached from waste by storm water and thus infiltrated the paleosol.
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Hossain MS, Balakrishnan V, Rahman NNNA, Rajion ZA, Kadir MOA. Modeling the inactivation of Staphylococcus aureus and Serratia marcescens in clinical solid waste using supercritical fluid carbon dioxide. J Supercrit Fluids 2013. [DOI: 10.1016/j.supflu.2013.08.011] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
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