11 research outputs found

    Some ecological factors affecting the input and population level of total and faecal coliforms and salmonella in Twelve Mile Creek, Lake Ontario and sewage waters near St. Catharines, Ontario

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    Some Ecological Factors Affecting the Input and Population Levels of Total and Faecal Coliforms and Salmonella in Twelve Mile Creek, Lake Ontario and Sewage Waters Near St. Catharines, Ontario. Supervisor: Dr. M. Helder. The present study was undertaken to investigate the role of some ecological factors on sewage-Dorne bacteria in waters near St. Catharines, Ontario. Total and faecal coliform levels and the presence of Salmonella were monitored for a period of a year along with determination of temperature, pH, dissolved oxygen, total dissolved solids, nitrate N, total phosphate P and ammonium N. Bacteriological tests for coliform analysis were done according to APHA Standard Methods by the membrane filtration technique. The grab sampling technique was employed for all sampling. Four sample sites were chosen in the Port Dalhousie beach area to determine what bacteriological or physical relationship the sites had to each other. The sample sites chosen were the sewage inflow to and the effluent from the St. Catharines (Port Dalhousie) Pollution Control Plant, Twelve Mile Creek below the sewage outfall and Lake Ontario at the Lakeside Park beach. The sewage outfall was located in Twelve Mile Creek, approximately 80 meters from the creek junction with the beach and piers on Lake Ontario. Twelve Mile Creek normally carried a large volume of water from the WeIland Canal which was diverted through the DeCew Generating Station located on the Niagara Escarpment. An additional sample site, which was thought to be free of industrial wastes, was chosen at Twenty Mile Creek, also in the Niagara Region of Ontarioo 3 There were marked variations in bacterial numbers at each site and between each site, but trends to lower_numbers were noted from the sewage inflow to Lake Ontario. Better correlations were noted between total and faecal coliform population levels and total phosphate P and ammonium N in Twenty Mile Creek. Other correlations were observed for other sample stations, however, these results also appeared to be random in nature. Salmonella isolations occurred more frequently during the winter and spring months when water temperatures were minimal at all sample stations except the sewage inflow. The frequency of Salmonella isolations appeared to be related to increased levels of total and faecal coli forms in the sewage effluent. However, no clear relationships were established in the other sample stations. Due to the presence of Salmonella and high levels of total and faecal coliform indicator organisms, the sanitary quality of Lake Ontario and Twelve Mile Creek at the sample sites seemed to be impaired over the major portion of the study period

    Characterization and nutritional study of the heterotrophic bacteria from marine benthic algae.

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    Miu-kuen Kong.Thesis (M. Ph.)--Chinese University of Hong Kong.Bibliography: leaves 164-186

    Studies on Campylobacter fetus subspecies jejuni

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    The work described in this thesis was principally directed at trying to develop a mouse model for human campylobacteriosis and also at defining the antigenic relationships between the human strains. Human diarrhoeal and normal stool specimens were examined for Campylobacter fetus ss, jejuni by culture on plates of Campylobacter selective medium, incubated at 4

    Novel inhibitors of the bacterial de novo purine biosynthesis enzymes, n5-carboxyaminoimidazole ribonucleotide synthetase and mutase

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    Antibiotic resistance has seen a significant increase during the past decade. The increasing frequency of the drug-resistant bacterial infections has amplified the need for novel antimicrobial agents. De novo purine biosynthesis is one area that has great potential for antibacterial drug development because this pathway is different in microorganisms versus humans. The difference in the pathway is centered on the synthesis and utilization of the purine intermediate N5-carboxy-5-aminoimidazole ribonucleotide (N5-CAIR). Previous studies have shown that N5-CAIR is a key intermediate in purine biosynthesis in bacteria, yeast and fungi, but not in humans. N5-CAIR is synthesized from 5-aminoimidazole ribonucleotide (AIR) by the enzyme N5-CAIR synthetase and it is utilized by N5-CAIR mutase to produce the intermediate 4-carboxy-5-aminoimidazole ribonucleotide (CAIR). In our laboratory we explored both enzymes as potential targets for the design of novel de novo purine biosynthesis inhibitors. Previous studies suggested that the isatin-based inhibitors were promising low micromolar inhibitors of N5-CAIR synthetase. Here, the biological verification of the isatin compounds as potential hits and their kinetic analysis are presented. The second project involves the discovery, kinetic evaluation, molecular modeling, and exploratory synthesis of the first known, selective inhibitor of N5-CAIR mutase

    Studies on serological variation among bovine rotaviruses

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    All 12 field strains of rotavirus used initially to provide virus stock and convalescent antisera were capable of multiplying in gnotobiotic Lambs but without inducing diarrhoea. None grew on primary bovine and ivine embryonic kidney cell cultures nor on MDBK, LLC-MK2 and Vero cell Lines but all adapted well to growth in roller cultures of MA104 cells ireated with lOpg/ml of trypsin. Pre-treatment of virus inocula was essential for further propagation of the virus strains on MA104 cells.Because 4 of 12 original strains were found to contain more than one rotavirus electrophoretype, the remaining 8 strains were selected for more letailed serological investigations. Neutralisation tests using convalescent lamb antisera and hyperimmune rabbit antisera against faecal ind tissue culture viruses confirmed the presence of two distinct serotypes; in that they showed more than a 20-fold reciprocal difference Ln titre and an antigenic relatedness value of less than 5%. When samples cf infected calf faeces were titrated in hyperimmune antisera to these two serotypes, four untypable rotaviruses were isolated of which three belonged to a hitherto unknown third serotype, while the fourth strain showed a partial relationship to this new serotype.In summary of the 108 calf rotavirus strains examined, no fewer than JO (74%) including the UK(Compton), Northern Ireland, and Lincoln strains belonged to serotype 1, one was identified as serotype 2 and three as serotype 3. Of the remainder, one had a partial relationship to serotype J while 23 produced insufficient fluorescing foci to enable them to be characterised fully. Attempts to develop ELISA and HAI tests for the letection of rotaviruses of serotypes 1 and 2 in diagnostic faecal samples croved unsuccessful.Examination of the electrophoretypes of rotavirus involved in 30 outbreaks of diarrhoea in calves revealed that one strain usually predominated in each individual herd, although infection with multiple strains occurred on 5 of the farms examined. There was no evidence that jenomic and polypeptide variations exhibited by the calf rotaviruses were related to their serotypic differences.In experimental calf, infection of ligated gut loops showed that variations in virulence were obtained with different strains of rotavirus, ilthough no correlation occurred between virulence and the serotypes used, fhere was no appreciable difference between faecal and tissue culture virus in the: ability to infect intestinal epithelial cells and most rended to favour the ileal (middle and distal) rather than the jejunal [proximal) parts of the small intestine for replication.The practical importance of indentifying rotavirus serotypes was :onfirmed by passive cross-protection immunisation experiments in jnotobiotic lambs. Thus lambs fed with antiserum for three successive lays and challenged with rotavirus between the first and second feeds showed good protection against the homologous virus; but there was no pross-protection; affected lambs excreted the challenge virus at similar :itres and over the same period as did unprotected control lambs

    Biogenic Amines and Food Safety

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    Biogenic amines are bioactive compounds distributed in foods of all origins. Apart from their fundamental role in many bodily functions, there has recently been great interest in their toxicological potential, much research is being carried out to understand their occurrence related to both desired and undesired fermentative phenomena, chemical spoilage, low hygienic conditions, wrong handling, and criticism about technological factors of process and storage conditions. All these causes can contribute to a higher content of biogenic amines in food, particularly of those hazardous to human health. This book aims to collect scientific studies looking for new tools to limit the over-production of biogenic amines in food, search for new food sources of biogenic amines, and to spotlight the concept of safe food and bioactive amines content

    CBRN

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    "Since 2001, the U.S. Department of Health and Human Services (HHS), Centers for Disease Control and Prevention (CDC), National Institute for Occupational Safety and Health (NIOSH) has established performance and design standards for respiratory protective devices (RPDs) to protect against chemical, biological, radiological, and nuclear (CBRN) hazards and toxic industrial chemicals. Prior to 2001, there were no standards for the use of RPDs by U.S. emergency response personnel that covered the full range of expected CBRN threats. Federal regulations require emergency response personnel to use respirators approved by NIOSH for the expected hazards. Equipment performance standards were needed to protect against CBRN threats. Neither industrial nor military respirators provided protection from all potential CBRN respiratory hazards. Several federal agencies partnered to provide research and testing to produce the necessary standards: Department of Justice (DOJ); Department of Homeland Security (DHS); Department of Defense (DoD), U.S. Army Research, Development and Engineering Command (RDECOMa); Department of Commerce (DOC), National Institute for Standards and Technology (NIST); and the Department of Labor (DOL), Occupational Safety and Health Administration (OSHA). The NIOSH RPD approval standards and tests developed for CBRN protections are highly specialized. The advanced CBRN respirators have unique characteristics related to selection, use, and maintenance compared to NIOSH-approved industrial respirators. Due to the enhanced protection afforded by NIOSH-approved CBRN respirators, it is likely that the respirators will also be used in industrial applications. Nationally prominent organizations have identified the need for advice and training on CBRN respirators. Among these are the RAND Corporation, Science and Technology Policy Institute, and the Federal InterAgency Board (IAB) for Equipment Standardization and Interoperability. Responders in several RAND studies clearly expressed the need for guidelines related to personal protective equipment (PPE), including respirators [Bartis et al. 2005; Jackson et al. 2002; Jackson et al. 2004; LaTourrette et al. 2003; Willis et al. 2006]. As early as 2002, RAND reported: One of the clear messages of the conference (December 10, 2001) was that most emergency workers do not believe that they are prepared with the necessary information, training, and equipment to cope with many of the challenges associated with the response to a major disaster such as the World Trade Center attack or for threats associated with anthrax, and similar agents [Jackson et al. 2002]. Another RAND study indicated: In sum, community representatives stressed that a greater amount of training and education must be part of any policy to improve the protection of emergency responders in the line of duty [LaTourrette et al. 2003]. An IAB annual report also underscored the need for guidance: The emergency responder community has a need for guidance and information on the selection, use, and maintenance of CBRN respirators to ultimately reduce incidences of respiratory related injury for nearly 4 million career and volunteer corrections, emergency medical services, firefighting, and law enforcement responders [IAB 2009]. This handbook fills the critical need for authoritative technical information on CBRN RPDs. The information presented will assist any user of CBRN respirators to improve selection, use, and maintenance, but it is particularly useful to those individuals responsible for administering respirator protection programs or developing training programs. The handbook is intended for organizations that use CBRN respirators in emergency response applications (e.g., fire service, law enforcement, emergency medical services, and corrections officers). It does not include information on how to conduct response activities. Others who use CBRN respirators in industrial, public works, construction, utility, and other non-emergency applications will also benefit from the information presented. The information in the following chapters can be used to develop a more effective CBRN respiratory protection program and establish effective training programs in support of other requirements such as relevant National Fire Protection Association (NFPA) and OSHA standards. Relevant NFPA standards include NFPA 472 (Standard for Competence of Responders to Hazardous Materials/ Weapons of Mass Destruction Incidents) and NFPA 473 (Standard for Competencies for EMS Personnel Responding to Hazardous Materials/Weapons of Mass Destruction Incidents). Relevant OSHA and EPA standards include Title 29 Code of Federal Regulations (CFR) 1910.134 (Respiratory Protection) and 1910.120 (Hazardous Waste Operations and Emergency Response), and Title 40 CFR Chapter 1, Part 311 (Worker Protection)." - NIOSHTIC-2NIOSHTIC no. 20052066Suggested citation: NIOSH [2018]. CBRN respiratory protection handbook. By Janssen L, Johnson AT, Johnson JS, Mansdorf SZ, Medici OR, Metzler RW, Rehak TR, Szalajda JV. Pittsburgh, PA: U.S. Department of Health and Human Services, Centers for Disease Control and Prevention, National Institute for Occupational Safety and Health, DHHS (NIOSH) Publication No. 2018-166, https://doi.org/10.26616/NIOSHPUB2018166.Appendix A: CBRN Respirator Standards -- Appendix B: OSHA CBRN Fit Testing Interpretation Letter -- Appendix C: Respiratory Protection Program Samples2018https://doi.org/10.26616/NIOSHPUB201816

    Radiation protection programme. Progress report 1982. EUR 8486 DE/EN/FR

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