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L'augmentation et la dissémination de la résistance aux antibiotiques chez les bactéries à gram-negatif, particulièrement les Entérobactéries, les bactéries du genre Pseudomonas et Acinetobacter, représentent un problème majeur de santé publique au niveau mondial. Les infections nosocomiales causées par les bactéries multi-résistantes (BMR) ont conduit non seulement à une augmentation de la mortalité, de la morbidité, et du coût de traitement, mais aussi continuent de mettre en danger la vie des patients surtout immunodéprimés en milieu hospitalier. Bien entendu, l'utilisation abusive et non contrôlée des antibiotiques a grandement contribué à la large diffusion des déterminants de la résistance; cependant, des études récentes ont démontré que ces déterminants de la résistance pouvaient émerger à partir de sources anciennes et/ou environnementales. Ainsi, face à cette préoccupation mondiale, plusieurs études ont été rapportées avec des recommandations importantes de conduire des études épidémiologiques, moléculaires, et génomiques afin de contrôler la diffusion et l'augmentation de la résistance aux antibiotiques. De plus, durant ces 10 dernières années, nous avons assisté à l'emergence et au développement de nouvelles technologies de séquençage à haut débit coïncidant avec une augmentation exponentielle du nombre de genomes bactériens séquencés. / The increase and spread of multidrug-resistant (MDR) gram-negative bacteria especially Enterobacteriaceae, Pseudomonas, and Acinetobacter (E.P.A) species have become a major concern worldwide. The hospital-acquired infections caused by MDR bacteria have led not only to an increase in mortality, morbidity, and cost of treatment, but also continue to endanger the life of patients, especially those immunocompromised. Although the frequent misuse of antibiotic drug has greatly contributed to worldwide dissemination and resistance to antibiotics; recent studies have shown that these resistance determinants could emerge from ancient or environmental sources. Front of this worldwide concern, several studies have been reported with significant recommendations to conduct molecular epidemiology, and genomic studies, in order to control the increase and the dissemination of the antibiotic resistance. Moreover, during these last 10 years, we are witnessing the emergence and development of new technologies of high throughput sequencing and coinciding with an exponential increase of number of bacterial genomes sequenced today. Therefore, it is in this context that the project of this thesis was conducted with three essential objectives: (i) the genome sequencing of clinical MDR bacteria, the analysis and the identification of the mechanisms and the genetic determinants of antimicrobial resistance (ii) the achievement of molecular epidemiology studies from clinical MDR bacteria responsible of outbreak (iii) the development and implementation of molecular tools for monitoring and diagnosis of potential MDR bacteria.

Genom ökad användning på träningskläder har antibakteriella behandlingar blivit allt vanligare för den allmänna konsumenten. Dessa plagg marknadsförs ofta som antibakte-riella eller luktfria, men det som inte framgår är vilka ämnen som används för att uppnå den luktfria effekten. Vanligt förekommande är de behandlingar som är baserade på oorganiska silversalter. Medan leverantörerna av dessa produkter argumenterar för, argumenterar många miljövetare och forskare på bakterier emot antibakteriella produk-ter då dessa kan ha en skadlig inverkan på vår miljö och hälsa. Rapporten syftar till att ge större kunskap kring miljö- och hälsopåverkan vid användandet av textiler behandlade med silversalter samt till att analysera konsumenters inställning till antibakteriella kläder samt deras användar- och tvättvanor för träningskläder. Rapporten söker svar på om fördelarna med dessa silversaltbaserade antibakteriella behandlingar överväger nackde-larna. Insamlad teori inom området har sammanställts för att sedan testas mot empirin i form av intervjuer, enkätundersökning och användartest. De antibakteriella behandling-arna verkar oftast genom controlled-release principen vilken innebär att tillförsel av fukt krävs för att de verksamma antibakteriella ämnena ska aktiveras och förgöra eller hämma bakterietillväxten på tyget. Tester har visat att varje gång ett behandlat plagg tvättas läcker en del av de bakteriedödande silverjonerna ut i vårt allmänna avlopp och en del hamnar på övriga textilier i tvättmaskinen. En del av silverjonerna förenar sig i avloppsvattnet med svaveljoner och bildar den svårlösliga föreningen silversulfid. Silver i jonform är mycket giftigt för vattenlevande organismer och kan orsaka skadliga lång-tidseffekter på vattenmiljö och lätt bioackumuleras. Forskare har undersökt hur användaren av plagg behandlade med silverjoner påverkas. De drar som slutsats av studien att hudens naturliga bakterieflora och mikroklimat förblir nästintill opåverkade och klassar därför den antibakteriella textilen som användarsäker. Ytterligare forskning har dock visat att bakterier har förmåga att utveckla resistens mot silver på samma sätt som mot antibiotika. Ökad användning av silver i konsumentprodukter skulle därför kunna bidra till en ökad spridning av antibiotikaresistens. Ett säljargument som används av flera marknadsaktörer är den minskade energi- och vattenförbrukningen i användar-fasen, då konsumenten inte behöver tvätta ett antibakteriellt plagg lika ofta som ett obehandlat. För att ta reda på om argumentet stöds i praktiken genomfördes en enkät-undersökning. Utifrån enkätsvaren framgår det tydligt att dessa behandlingar varken påverkar användar- eller tvättvanor och inte heller är något som efterfrågas av konsu-menten i första hand vid inköp av träningskläder. Ett användartest genomfördes för att undersöka om den antibakteriella behandlingen gör någon märkbar skillnad för använ-daren, genom att minska den dåliga odören på plagget. Slutsatsen drogs att det inte är någon markant skillnad på ett behandlat respektive obehandlat träningsplagg. Baserat på de teoretiska fakta om silverjoners negativa påverkan på miljö och människors hälsa, främst i form av risk för utveckling av resistenta bakterier, samt grundat på de empiriska resultaten från användartest och enkät så dras slutsatsen att fördelarna inte överväger nackdelarna med dessa behandlingar och det rekommenderas starkt att inte använda någon antibakteriell behandling innehållande silversalter.Through increased use on sport clothing, antibacterial treatments have become increas-ingly common for the general consumer. These are often marketed as antibacterial and odor-free, but what is not clear is what kind of substances that are used to achieve the odor-free effect. Usually these are based on inorganic silver salts. While suppliers of antibacterial products advocates these, many scientists in environmental science and bacteriological research discourage to the use as they may have an adverse impact on our environment and health. The report aims to provide greater knowledge about environmental and health impacts from the use of fabrics treated with silver salts, and to analyze consumer’s attitude to antibacterial clothes and their patterns of behavior and laundry habits for sport clothes. The report seeks to answer if the benefits of these silver salt-based antibacterial treatments outweigh the disadvantages. Collected theory in the field was compiled and then tested against empirical data in the form of inter-views, survey and consumer test. Laboratory tests have shown that each time a treated garment is washed some of the antimicrobial silver ions leaks into our public sewage and some sticks to other textiles in the washing machine. Some of the silver ions combine in the wastewater with sulfur ions to form the insoluble compound silver sulfide. Silver in ionic form is highly toxic to aquatic organisms and can cause long term adverse effects on aquatic life and easily bioaccumulate. Researchers have examined how users of garments treated with silver ions are affected. They draw as conclusion from the study that the skin's natural bacterial flora and micro-climate will remain unaffected and, therefore, categorizes the antibacterial fabrics as safe for the consumer. Further re-search has shown that bacteria have the ability to develop resistance to silver in the same way as to antibiotics. Increased use of silver in consumer products could therefore contribute to a greater spread of antibiotic resistance. A common sales argument used by many market participants is the reduced energy and water consumption in the con-sumer phase, where consumers do not need to wash antibacterial clothes as often as untreated. To find out if the argument is supported in practice, a survey was conducted. Based on the survey responses, it is clear that these treatments do not affect the con-sumer’s behavior in use or washing habits and is not demanded primarily by the consumer for the purchase of sport clothes. A consumer test was conducted to investi-gate whether the antibacterial treatment make any noticeable difference to the user, by reducing the bad odor in the clothes. It was concluded that there is no marked differ-ence in the treated and untreated sport clothes. Based on the theoretical facts about silver ions negative impact on the environment and human health, especially involving the risk of development of resistant bacteria, and based on the empirical results from consumer test and survey, it is concluded that the benefits of silver salt-based treat-ments do not outweigh the disadvantages and it is highly recommended to not use any antibacterial treatment containing silver salts. / Program: Textil produktutveckling med entreprenörs- och affärsinriktning

Industrial effluents with high concentrations of heavy metals are widespread pollutants of great concerns as they are known to be persistent and non-degradable. Continuous monitoring and treatment of the effluents become pertinent because of their impacts on wastewater treatment plants. The aim of this study is to determine the correlation between heavy metal pollution in water and the location of industries in order to ascertain the effectiveness of the municipal waste water treatment plant. Heavy metal identification and physico-chemical analysis were done using Inductively Coupled Plasma Optical Emission Spectrometry (ICP-OES) and multi-parameter probe respectively. Correlation coefficients of the measured values were done to investigate the effect of the industrial effluents on the treatment plants. Heavy metal resistant bacteria were identified and characterised by polymerase chain reaction and sequencing. Leeuwkuil wastewater treatment plants were effective in maintaining temperature, pH, and chemical oxygen demand within South Africa green drop and SAGG Standards whereas the purification plant was effective in maintaining the values of Cu, Zn, Al, temperature, BOD, COD, and TDS within the SANS and WHO standard for potable water. This findings indicated the need for the treatment plants to be reviewed.The industrial wastewater were identified as a point source of heavy metal pollution that influenced Leeuwkuil wastewater treatment plants and the purification plants in Vaal, Vereenining South Africa. Pseudomonas aeruginosa, Serratia marcescens, Bacillus sp. strain and Bacillus toyonensis that showed 100% similarity were found to be resistant to Al, Cu, Pb and Zn. These identified bacteria can be considered for further study in bioremediation. / Environmental Sciences / M. Sc. (Environmental Science)

Decreasing surface water quality in South Africa has become an issue of concern as the population grows, industrial and agricultural activities expand, and environmental pollution increases. Wastewater treatment plants and other anthropogenic activities are liable for releasing raw and inadequately treated effluents into the surface water. Extensive pollution accompanied by the use of disinfectants, pesticides, and other chemical pollutants has been attributed to increased antimicrobial resistance in bacteria such as Escherichia coli in surface water, increasing environmental antibiotic resistance spread. The research aimed to determine water quality and prevalence of antibiotic-resistant bacteria in Naauwpoortspruit River, eMalahleni, Mpumalanga Province. Five sampling sites were selected along the Naauwpoortspruit River and monitoring was done for seven consecutive months. Samples were collected and analysed for physicochemical, microbiological parameters, and susceptibility profile of antibiotic-resistant bacteria using standard methods. Pearson correlation analysis was used to assess the path and strength of the relationship between physicochemical and microbiological parameters in the study area. Results of physicochemical and microbial parameters showed variation throughout the selected study sites. The results revealed a pH range of 4.45 – 7.9 and electrical conductivity levels range of 58.63 - 113.3 mS/m for the different sampling sites during the study period with lower levels detected during the winter period and higher levels in the summer period. Also, water samples showed a high total dissolved solids levels range of 381.1 – 736.45 mg/L and biochemical oxygen demand range of 67.1 – 168 mg/L for the different sampling sites during the study period. The Naauwpoortspruit River had higher levels of ammonia of 33.4 mg/L at Point A during the winter period as compared to 15 mg/L in the summer period. Heavy metals results showed that mercury range of 0.01 – 0.065 mg/L and copper range of 0.001 – 0.0035 mg/L were not compliant with aquatic ecosystem guidelines at all selected sites throughout the study period. The foremost finding of this study was that E. coli were present in all the selected sites at concentrations (>100 cfu/100ml). Elevated concentrations of 5.4 x 103 and 4.2 x 103 cfu/100ml for the total and faecal indicator bacteria were detected from sites downstream to 2.2 x103 and 2.35 x103 cfu/100ml for sites upstream river, in the rainy months. During the dry season, total coliforms, and faecal coliforms concentration of 0.4 x103 to 0.65 x 103 cfu/100ml were detected downstream and 0.25 x 103 and 0.5 x 103 cfu/100ml from upstream, respectively. The physicochemical and microbiological parameters measured at selected sites exceeded acceptable limits and proved unsuitable for applications such as full and intermediate recreational activities, and aquatic ecosystems. The variation in physicochemical parameters results was influenced by both natural processes and human activities such as salinity and Acid Mine Drainage (AMD) within the Naauwpoortspruit River. Using the Kirby-Bauer disc diffusion method, E. coli and faecal coliforms were tested for resistance to antibiotics; ampicillin (10 μg/ml), kanamycin (30 μg), streptomycin (30 μg), chloramphenicol (30 μg), erythromycin (15 μg), ox tetracycline (30 μg), erythromycin (15 μg/ml) and norfloxacin (10 μg). More than 60% of faecal coliform were resistant to at least four of the tested antibiotics and between 60 - 80% of the E. coli isolates were resistant to β lactam. The highest microbial antibiotic resistance (MAR) index value was observed at Site D (0.38 for E. coli) which showed multi-antibiotic resistance. Site D is characterized by wastewater treatment, power generation industries, and agriculture activities. The highest level of MAR observed at Site D indicates the need to control extensive pollution and constantly monitor the changing trends in antimicrobial resistance patterns of these waterborne pathogens. Statistical analysis showed that the development of microbiological parameters loads has a strong correlation with physicochemical parameters due to the association of sampling sites in the river environment. This study shows that the aquatic ecosystem needs constant monitoring to establish their conditions, impacts of pollution activities within the catchment, and input information into sustainable management of the water resources. / Environmental Sciences / M. Sc. (Environmental Science)