<p>Streptococcus pneumoniae is a gram-positive bacterium that can be found in both healthy carriers as well as in people that have developed disease. One of the major virulence factors of pneumococci is their polysaccharide capsule. Based on the capsule that surrounds the bacteria, pneumococci are divided into at least 90 different serotypes. Some serotypes seem to be more related to virulence than others.</p><p>I have with comparative genome hybridization microarray technique, studied gene differences between 18 epidemiological well-characterised pneumococcal strains with different potential to cause disease. A microarray chip based on two sequenced pneumococcal genomes, R6 and TIGR4, has already been designed. According to Hierarchical clustering, both the serotype and the genetic type as assessed by MLST (sequence type or ST) seem to have impact on the relationship of clinical isolates. Most clinical isolates of the same serotype are clustered together except for serotype 14 isolates that seem to be more divergent. Further more the number of genes that are divergent between clinical isolates compared to R6 and TIGR4 differ from 65 to 289. Preliminary results indicate that although there is diversity among clinical isolates some are more closely related to each other then others. Absent genes seem to be evenly distributed among all 18 clinical isolates tested but hypothetical genes and genes for cell envelope are two groups of role categories that are absent to the largest extent in all isolates.</p><p>According to results from microarray analysis, a gene region, spr0112-spr1015- is present in all type 9V isolates and absent in many isolates of serotype 14, 19F and 7F. These results have been confirmed by polymerase chain reaction (PCR).</p><p>Conserved genes in a region around the capsule genes have been sequenced to identify marker genes for a capsulular switch between serotype 9V and 14. Preliminary results of the sequencing showed that as much as 750kb might have been transferred in the event of capsular switch.</p>

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<p>Gaut, S., 2005: Factors influencing microbiological quality of groundwater from potable water supply wells in Norwegian crystalline bedrock aquifers. Doktor Ingeniør thesis 2005:99. Department of Geology and Mineral Resources Engineering, NTNU, 153 pp and appendices.</p><p>Microbiological analyses from 195 Norwegian waterworks based on groundwater in bedrock have been examined to study the vulnerability of bedrock wells to microbiological contamination. Inspections have been carried out at 49 of the 195 waterworks to identify possible causes to the recorded microbiological contamination. It is found that groundwater derived from bedrock wells is susceptible to microbiological contamination and needs better protection. Seasonal variations in the water quality occur. Coliforms are mostly detected from June to September. <i>Cryptosporidium</i>, but not <i>Giardia</i>, is detected in the groundwater from three of twenty waterworks. The microbiological water quality is correlated to (i) wellhead completion (including the well casing), (ii) type and thickness of superficial deposits, (iii) land use and contamination sources and (iv) distance from wells to running water. Recommended wellhead completion includes a well-house and a casing of at least 5.5 m, rising 40-50 cm above ground. The gap between casing and bedrock should be sealed. Wells are least vulnerable to microbiological contamination when the superficial deposits are > 2.5 m thick and the wells are located > 100 m from farmland and not within 75-125 m of running water. Variations in parameters, such as colour, turbidity, and iron, and high levels of total organic carbon can indicate that the aquifer or the well is vulnerable to microbiological contamination. Vulnerability mapping combined with a hygienic evaluation of the well area and delineation of protection zones based on simple analytical methods is suggested as a method to protect Norwegian bedrock wells.</p>

<p>The aim of this project was to compare the use of the Swedish Reference Group of Antibiotics and the Clinical Laboratory standard institute disc diffusions method using a variety of antibiotics on Klebsiella species and Pseudomonas aeruginosa. After the disc diffusions methods a Vitek system and Etest where preformed on those isolates with a different or abnormal result.</p><p>Klebsiella spp. and P. aeruginosa was colleted in St James’s hospital over a period of four months. These two isolates were chosen because of their resistance pattern to many commonly used antibiotics and the threat of upcoming resistance to other antibiotics.</p><p>The SRGA method is know to have lower breakpoints to catch low degree of resistance bacteria, while the CLSI often is blamed for not having species specific MIC breakpoints.</p><p>The results in this study showed that the SRGA-m often caught more resistant and</p><p>intermediate isolates then the CLSI-m.</p>

Gaut, S., 2005: Factors influencing microbiological quality of groundwater from potable water supply wells in Norwegian crystalline bedrock aquifers. Doktor Ingeniør thesis 2005:99. Department of Geology and Mineral Resources Engineering, NTNU, 153 pp and appendices. Microbiological analyses from 195 Norwegian waterworks based on groundwater in bedrock have been examined to study the vulnerability of bedrock wells to microbiological contamination. Inspections have been carried out at 49 of the 195 waterworks to identify possible causes to the recorded microbiological contamination. It is found that groundwater derived from bedrock wells is susceptible to microbiological contamination and needs better protection. Seasonal variations in the water quality occur. Coliforms are mostly detected from June to September. Cryptosporidium, but not Giardia, is detected in the groundwater from three of twenty waterworks. The microbiological water quality is correlated to (i) wellhead completion (including the well casing), (ii) type and thickness of superficial deposits, (iii) land use and contamination sources and (iv) distance from wells to running water. Recommended wellhead completion includes a well-house and a casing of at least 5.5 m, rising 40-50 cm above ground. The gap between casing and bedrock should be sealed. Wells are least vulnerable to microbiological contamination when the superficial deposits are &gt; 2.5 m thick and the wells are located &gt; 100 m from farmland and not within 75-125 m of running water. Variations in parameters, such as colour, turbidity, and iron, and high levels of total organic carbon can indicate that the aquifer or the well is vulnerable to microbiological contamination. Vulnerability mapping combined with a hygienic evaluation of the well area and delineation of protection zones based on simple analytical methods is suggested as a method to protect Norwegian bedrock wells.

Streptococcus pneumoniae is a gram-positive bacterium that can be found in both healthy carriers as well as in people that have developed disease. One of the major virulence factors of pneumococci is their polysaccharide capsule. Based on the capsule that surrounds the bacteria, pneumococci are divided into at least 90 different serotypes. Some serotypes seem to be more related to virulence than others. I have with comparative genome hybridization microarray technique, studied gene differences between 18 epidemiological well-characterised pneumococcal strains with different potential to cause disease. A microarray chip based on two sequenced pneumococcal genomes, R6 and TIGR4, has already been designed. According to Hierarchical clustering, both the serotype and the genetic type as assessed by MLST (sequence type or ST) seem to have impact on the relationship of clinical isolates. Most clinical isolates of the same serotype are clustered together except for serotype 14 isolates that seem to be more divergent. Further more the number of genes that are divergent between clinical isolates compared to R6 and TIGR4 differ from 65 to 289. Preliminary results indicate that although there is diversity among clinical isolates some are more closely related to each other then others. Absent genes seem to be evenly distributed among all 18 clinical isolates tested but hypothetical genes and genes for cell envelope are two groups of role categories that are absent to the largest extent in all isolates. According to results from microarray analysis, a gene region, spr0112-spr1015- is present in all type 9V isolates and absent in many isolates of serotype 14, 19F and 7F. These results have been confirmed by polymerase chain reaction (PCR). Conserved genes in a region around the capsule genes have been sequenced to identify marker genes for a capsulular switch between serotype 9V and 14. Preliminary results of the sequencing showed that as much as 750kb might have been transferred in the event of capsular switch.

The aim of this project was to compare the use of the Swedish Reference Group of Antibiotics and the Clinical Laboratory standard institute disc diffusions method using a variety of antibiotics on Klebsiella species and Pseudomonas aeruginosa. After the disc diffusions methods a Vitek system and Etest where preformed on those isolates with a different or abnormal result. Klebsiella spp. and P. aeruginosa was colleted in St James’s hospital over a period of four months. These two isolates were chosen because of their resistance pattern to many commonly used antibiotics and the threat of upcoming resistance to other antibiotics. The SRGA method is know to have lower breakpoints to catch low degree of resistance bacteria, while the CLSI often is blamed for not having species specific MIC breakpoints. The results in this study showed that the SRGA-m often caught more resistant and intermediate isolates then the CLSI-m.

In nature, urea is hydrolyzed to ammonia and bicarbonate primarily by enzymes called ureases. As urine waste contains multiple important plant nutrients, there is interest in the waste treatment field to use urine waste products as plant fertilizers. Since urease enzymes are usually found in biofilms, one can prevent nitrogen loss in urine waste by preventing biofilm formation in the surrounding environment. In recent years, many new strategies to prevent microbial growth have been developed, especially within the field of nanoscience. The aim of this master's thesis was to develop a method for growing and analyzing urease-active biofilms and to investigate whether super-acidic metal- oxide surfaces could prevent biofilm growth. In this project, the methods are divided into two sections: methods for producing super-acidic metal-oxide surfaces and methods for growing and analyzing biofilms. The method for growing biofilms was developed through successive experiments, with the results of one experiment being used to design the next. Three batches of antimicrobial plates were manufactured, and seven biofilm experiments were conducted. In these experiments, biofilms were able to grow on antimicrobial plates, but the results were somewhat inconclusive. The biofilms were analyzed by microscopy, since no quantitative analysis method was successful in this study.

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