Serum amyloid A protein (SAA) is an acute phase protein that has recently gained increasing interest as a potential marker for disease and treatment monitoring. We investigated SAA and CRP levels in (a) patients with various common infectious diseases (n=98), (b) patients with pyelonephritis (n=37) versus patients with cystitis (n=32), (c) healthy individuals of varying ages (n=231), (d) very immature newborn infants with or without nosocomial infections (NIs) (n=72) and (e) patients with bacterial infections treated with cefuroxime (n=81). SAA significantly correlated with CRP in viral as well as in bacterial infections (for the total group: r2=0.757, p<0.0001) and showed a systemic inflammatory response in 90% of the patients with cystitis as compared with 23% for CRP. Equally high efficiencies (0.96 and 0.94 for SAA and CRP, respectively) were observed in discriminating between pyelonephritis and cystitis. SAA and high sensitive (hs) CRP were lower in umbilical cords (p<0.0001) and higher in elderly adults (p<0.0001-0.03) than in the other age groups; higher in immature newborn infants than in term infants; and higher in the NI group than in the non-NI group. Interindividual variabilities of the time course of the biomarkers SAA and CRP were considerable. Because of the smoothed distribution of SAA and CRP (i.e. elevations were both essentially unchanged during the first 3 days of cefuroxime treatment), these markers were not useful when deciding parenteral-oral switch of therapy, which occurred within this time period in most cases. SAA is a sensitive systemic marker in cystitis. SAA and hsCRP in umbilical cord blood are close to the detection limit and increase with age. They increase in relation to NI in very immature newborn infants and might therefore be used in diagnosis and monitoring. Finally, SAA and CRP in adults with bacterial infections could not predict an early parenteral-oral switch of antimicrobial therapy.

<p><i>Chlamydophila pneumoniae</i> (<i>C. pneumoniae</i>) has been suggested as a stimulator of chronic inflammation in atherosclerosis. <i>C. pneumoniae</i> DNA was demonstrated in aortic biopsies in 50% of patients with stable angina pectoris or acute coronary syndrome undergoing coronary artery bypass grafting. <i>C. pneumoniae</i> mRNA, a marker of replicating bacteria, was demonstrated in 18% of the aortic biopsies. </p><p>Inflammation may have a role in the pathogenesis of thoracic aortic aneurysm, aortic dissection and aortic valve stenosis. <i>C. pneumoniae </i>DNA was demonstrated in aortic biopsies in 26% of thoracic aortic aneurysm patients and in 11% of aortic dissection patients undergoing thoracic surgery and in 22% of stenotic aortic heart valves from patients undergoing aortic valve replacement. No bacterial mRNA was demonstrated in these aortic biopsies, nor in the valves, suggesting that the infection has passed into a persistent state. <i>C. pneumoniae</i> DNA was demonstrated in peripheral blood mononuclear cells in only 5% of aortic valve stenosis patients and not in thoracic aortic aneurysm or aortic dissection patients, suggesting that the bacterium disseminated to the cardiovascular tissue long before the patient required surgery. The copper/zinc ratio in serum, a marker of infection/inflammation, was significantly elevated in thoracic aortic aneurysm patients, supporting an inflammatory pathogenesis. Patients positive for <i>C. pneumoniae</i> in the aortic valve had more advanced coronary atherosclerosis, further supporting a possible role for <i>C. pneumoniae</i> in atherosclerosis. </p><p>Mice were infected with <i>C. pneumoniae</i> that disseminated to all organs investigated (i.e. lungs, heart, aorta, liver and spleen). Trace element concentrations were altered in infected animals with an increased copper/zinc ratio in serum, a progressively increased iron concentration in the liver and a progressively decreased iron concentration in serum. Iron is important for <i>C. pneumoniae</i> metabolism, and a changed iron homeostasis was noted in infected mice by alterations in iron-regulating proteins, such as DMT1 and hepcidin.</p>

<p>Tuberkulos (tbc) är en luftburen droppsmitta orsakad av mykobakterium tuberkulosis. Tbc är den sjukdom som efter AIDS orsakar flest dödsfall, trots att botande behandling finns. Behandlingen är krävande för den tbc-smittade att genomgå och bygger på en kombination av en rad antibiotika som måste intas under minst sex månader. Ett avvikande i behandlingen kan resultera i att mykobakterium tuberkulosis blir resistent mot de ordinerade antibiotika. Följsamhet av långtidsbehandlingar som tbc-behandling graderas till 50 %. Syftet med litteraturstudien var att ur ett globalt perspektiv beskriva hur sjuksköterskan kan påverka följsamhet vid tbc-behandling i syfte att minska resistensutvecklingen av mykobakterium tuberkulosis. Studien genomfördes som en litteraturstudie där 12 vetenskapliga artiklar granskades och analyserades. Resultatet visar tydligt att specifika faktorer påverkar följsamhet och därigenom resistensutvecklingen. Faktorerna innefattar patientundervisning, behandlingsstrategier, omgivningens påverkan och stöd.  Undervisningen resulterar i att patienten får ökad förståelse för behandlingen. För att minska stigmatiseringen och det lidande den innebär för den tbc-smittade är även omgivningen i behov av ökad kunskap och information om tbc. Ett flertal studier visar att DOTS-strategin är betydelsefull för ökad följsamhet vid antituberkulos behandling. Litteraturstudien medför ett förslag om att sjuksköterskeprogrammet ska öka fokuseringen på följsamhet vid läkemedelsanvändning. Sjuksköterskan är i behov av att redan under grundutbildningen få kunskap om ansvarsfull antibiotikahantering som leder till en följsamhetsomtanke.</p> / <p>Tuberculosis (TB) is an airborne droplet infection caused by mycobacterium tuberculosis. TB is the disease after AIDS that is most deadly, even though curative treatment exists. The treatment is demanding for the TB-infected to undergo and consists of a combination of a number of antibiotics that must be administered for at least six months. A dissenting in anti-tuberculosis treatment might result in mycobacterium tuberculosis strains that are resistant to antibiotics. As adherence to long-term treatment is graded at a low percentage (50 %) the aim of the literature study was from a global perspective to develop a working-strategy for nurses that promote compliance in TB-treatment in order to reduce resistance development of mycobacterium tuberculosis. The study was conducted as a literature study where 12 research articles were reviewed and analyzed. The results describe specific factors that are essential to compliance. These factors comprise patient education, treatment strategies, social influences and support. As knowledge gives the patient a better understanding for the treatment it provokes compliance. The social environment of the TB-infected patient demands increased knowledge in order to reduce stigma. Several studies show that the DOTS strategy is important for increasing compliance in anti-tuberculosis treatment. The literature study results in a proposal for the nursing program to focus more on compliance in taking medication. The nursing program’s attendants need to gain knowledge about prudent antibiotic treatment that leads to a compliance concern.</p>

<p>Extensive use of the sulphonamide drugs against the bacterium <i>Neisseria meningitidis</i> has resulted in drug resistance development. Sulphonamide resistance in <i>N. meningitidis</i> is caused by alterations in the chromosomal <i>folP</i> gene, coding for DHPS (dihydropteroate synthase). One type of resistant DHPS has high sequence divergence compared to DHPS from susceptible strains. This divergent DHPS has a duplication of two amino acids, crucial for resistance, and an altered amino acid in position 68, important for both resistance and substrate binding. When introduced into a susceptible DHPS, these two alterations did not incur resistance and resulted in abnormal substrate binding properties. This indicated that the divergent DHPS was not directly developed by mutations, but rather had been acquired by horizontal transfer of <i>folP</i> from another species.</p><p>Commensal <i>Neisseria</i> species are implied as the origin of the horizontally transferred resistance. Sulphonamide-resistant commensal <i>Neisseria</i> isolates were detected in throat swabs from healthy individuals not exposed to these drugs; however, transformation of resistance from these commensals to <i>N. meningitidis</i> was restricted in the laboratory. A comparison of the genomic region surrounding <i>folP</i> revealed differences in gene organisation and in the DNA uptake sequence between <i>N. meningitidis</i> and distantly related commensals. These differences are likely to restrict transformation between distantly related <i>Neisseria</i> species.</p><p>DHPS participates in the folate biosynthesis pathway. The enzyme preceding DHPS in the pathway, HPPK (hydroxymethyl-dihydropterin pyrophosphokinase), from <i>N. meningitidis</i> was characterised and a method for studying substrate channelling from HPPK to DHPS was developed. The information gained could be exploited in the search for new antibiotics.</p><p>In conclusion, well-adapted sulphonamide-resistant strains of <i>N. meningitidis</i> and commensal <i>Neisseria</i> are established in the bacterial population and resistance can be horizontally spread by natural transformation. This may explain the abundance of sulphonamide-resistant <i>N. meningitidis</i>, although these drugs are no longer used against this bacterium.</p>

Extensive use of the sulphonamide drugs against the bacterium Neisseria meningitidis has resulted in drug resistance development. Sulphonamide resistance in N. meningitidis is caused by alterations in the chromosomal folP gene, coding for DHPS (dihydropteroate synthase). One type of resistant DHPS has high sequence divergence compared to DHPS from susceptible strains. This divergent DHPS has a duplication of two amino acids, crucial for resistance, and an altered amino acid in position 68, important for both resistance and substrate binding. When introduced into a susceptible DHPS, these two alterations did not incur resistance and resulted in abnormal substrate binding properties. This indicated that the divergent DHPS was not directly developed by mutations, but rather had been acquired by horizontal transfer of folP from another species. Commensal Neisseria species are implied as the origin of the horizontally transferred resistance. Sulphonamide-resistant commensal Neisseria isolates were detected in throat swabs from healthy individuals not exposed to these drugs; however, transformation of resistance from these commensals to N. meningitidis was restricted in the laboratory. A comparison of the genomic region surrounding folP revealed differences in gene organisation and in the DNA uptake sequence between N. meningitidis and distantly related commensals. These differences are likely to restrict transformation between distantly related Neisseria species. DHPS participates in the folate biosynthesis pathway. The enzyme preceding DHPS in the pathway, HPPK (hydroxymethyl-dihydropterin pyrophosphokinase), from N. meningitidis was characterised and a method for studying substrate channelling from HPPK to DHPS was developed. The information gained could be exploited in the search for new antibiotics. In conclusion, well-adapted sulphonamide-resistant strains of N. meningitidis and commensal Neisseria are established in the bacterial population and resistance can be horizontally spread by natural transformation. This may explain the abundance of sulphonamide-resistant N. meningitidis, although these drugs are no longer used against this bacterium.

Chlamydophila pneumoniae (C. pneumoniae) has been suggested as a stimulator of chronic inflammation in atherosclerosis. C. pneumoniae DNA was demonstrated in aortic biopsies in 50% of patients with stable angina pectoris or acute coronary syndrome undergoing coronary artery bypass grafting. C. pneumoniae mRNA, a marker of replicating bacteria, was demonstrated in 18% of the aortic biopsies. Inflammation may have a role in the pathogenesis of thoracic aortic aneurysm, aortic dissection and aortic valve stenosis. C. pneumoniae DNA was demonstrated in aortic biopsies in 26% of thoracic aortic aneurysm patients and in 11% of aortic dissection patients undergoing thoracic surgery and in 22% of stenotic aortic heart valves from patients undergoing aortic valve replacement. No bacterial mRNA was demonstrated in these aortic biopsies, nor in the valves, suggesting that the infection has passed into a persistent state. C. pneumoniae DNA was demonstrated in peripheral blood mononuclear cells in only 5% of aortic valve stenosis patients and not in thoracic aortic aneurysm or aortic dissection patients, suggesting that the bacterium disseminated to the cardiovascular tissue long before the patient required surgery. The copper/zinc ratio in serum, a marker of infection/inflammation, was significantly elevated in thoracic aortic aneurysm patients, supporting an inflammatory pathogenesis. Patients positive for C. pneumoniae in the aortic valve had more advanced coronary atherosclerosis, further supporting a possible role for C. pneumoniae in atherosclerosis. Mice were infected with C. pneumoniae that disseminated to all organs investigated (i.e. lungs, heart, aorta, liver and spleen). Trace element concentrations were altered in infected animals with an increased copper/zinc ratio in serum, a progressively increased iron concentration in the liver and a progressively decreased iron concentration in serum. Iron is important for C. pneumoniae metabolism, and a changed iron homeostasis was noted in infected mice by alterations in iron-regulating proteins, such as DMT1 and hepcidin.

Infectious diseases such as malaria and relapsing fever borreliosis (RF), cause severe human mortality and morbidity in developing countries. Malaria, caused by Plasmodium spp. parasites, is estimated by the World Health Organization to cause 1.5-2.7 million deaths annually. RF, caused by Borrelia spirochetes, has the highest prevalence described for any bacterial disease in Africa, with infection outcomes ranging from asymptomatic to fatal. RF borreliosis manifests in humans as a recurring fever and with other symptoms very similar to those of malaria. RF borreliosis has been regarded as a transient infection of the blood. However, B. duttonii exploits the brain as an immunoprivileged site escaping the host immune response while spirochetes in the blood are cleared. To investigate whether residual bacteria are dormant or actively dividing, mice with residual brain infection were administered ceftriaxone, a β-lactam antibiotic interfering with cell wall synthesis. Hence, it only affects actively dividing bacteria. Ceftriaxone eradicated brain RF infection in all treated mice, demonstrating that the bacteria are actively multiplying rather than in a dormant state. The findings support the therapeutic use of ceftriaxone for RF neuroborreliosis since penetration into cerebrospinal fluid is greater for ceftriaxone than for the often recommended doxycycline. The clinical features of malaria and RF are similar and diagnosis is further complicated by the frequently occurring concomitant malaria-RF infections. Therefore, we established a mouse model to study the pathogenesis and immunological response to Plasmodium/Borrelia mixed infection. Interestingly, malaria was suppressed in the co-infected animals whereas spirochete numbers were elevated 21-fold. The immune response in the concomitantly infected mice was polarized towards malaria leaving the spirochetes unharmed. Mice with co-infections also exhibited severe anemia and internal damages, probably attributed to escalating spirochete numbers. A secondary malaria infection reactivated the residual brain RF infection in 60% of the mice. This highlights the importance of co-infections as diagnostic pitfalls as well as the need for novel treatment strategies. Currently there is no commercial malaria vaccine and increasing drug resistance presents an urgent need for new malaria chemotherapeutics. Blood-stage malaria parasites are rapidly growing with high metabolic and biosynthetic activity, making them highly sensitive to limitations in polyamine supply. Disrupting polyamine synthesis in vivo with trans-4-methylcyclohexylamine (4MCHA) eradicated the malaria infection gradually, resulting in protective immunity. This leads the way for further biochemical and pharmacological development of the polyamine inhibitor 4MCHA and similar compounds as antimalarial drugs

Introduction: Nosocomial infections remain a major cause of mortality and morbidity. The problem is most apparent in intensive care units (ICUs). Most ICU patients are compromised and vulnerable as a result of disease or severe trauma. One in ten people admitted to hospital is given an antibiotic for infection. The risk of acquiring a nosocomial infection in a European ICU is approximately 20%. It is vitally important that ways are found to prevent transmission between patients and personnel, and that local hygiene routines and antibiotic policies are developed. This thesis is a holistic work focused particularly on antimicrobial antibiotic resistance, antibiotic consumption and to some extent on hygiene in Swedish ICUs. Aims: The general aim of this thesis was to investigate bacterial resistance and antibiotic consumption in Swedish ICUs and to try to correlate ICU demographic data with antibiotic consumption and antibiotic resistance. Additional aims were to investigate on which clinical indications antibacterial drugs are prescribed in the ICU, and to investigate the emergence of resistance and transmission of Pseudomonas aeruginosa in the ICU using cluster analysis based on antibiograms and genotype data obtained by AFLP. Material and methods: In paper 1-3, antibiotic consumption data together with bacterial antibiotic resistance data and specific ICU-demographic data were collected from an increasing number of ICUs over the years 1997-2001. Data from ICUs covering up to six million out of Sweden’s nine million inhabitants were included. In paper 4, the indications for antibiotic prescribing were studied during two weeks in 2000. Paper 5 investigated Pseudomonas aeruginosa isolates in order to detect cross-transmission with genotype obtained by AFLP, and antibiogram-based cluster analysis was also performed in order to see if this could be a quicker and easier substitute for AFLP. Results: This thesis has produced three important findings. Firstly, antibiotic consumption in participating ICUs was relatively high during the study period, and every patient received on average more than one antimicrobial drug per day (I-IV). Secondly, levels of antimicrobial drug resistance seen in S. aureus, E. coli and Klebsiella spp remained low when data were pooled from all ICUs throughout the study period, despite relatively high antibiotic consumption (I-V). Thirdly, the prevalence of antibiotic resistance in CoNS and E. faecium, cefotaxime resistance in Enterobacter, and ciprofloxacin and imipenem resistance in P. aeruginosa was high enough to cause concern. Conclusion: For the period studied, multidrug resistance in Swedish ICUs was not a major problem. Signs of cross-transmission with non-multiresistant bacteria were observed, indicating a hygiene problem and identifying simple improvements that could be made in patient care guidelines and barrier precautions. A need for better follow up of prescribed antibiotics was evident. With further surveillance studies and monitoring of antibiotics and bacterial resistance patterns in the local setting as well as on a national and international level, some of the strategic goals in the prevention and control of the emergence of antimicrobial-resistant microbes may be achievable.

Antibiotic resistance challenges the practice and development of modern medicine. The aim of this thesis was to test the hypothesis that antibiotic resistance is reversible once the selection pressure of an antibiotic is removed. A decisive reduction (85%) in trimethoprim and trimethoprim-sulfamethoxazole over 24 months in Kronoberg County, Sweden, is described. The resistance baseline prior to the intervention and the effects of the intervention on resistance levels, trimethoprim resistance genes (dfr-genes) and population structure in Escherichia coli were studied. The effects of different algorithms for excluding patient duplicate isolates were small but systematic. An identical algorithm was used throughout. The drastic decrease in the use of trimethoprim containing drugs did not result in a corresponding decrease in trimethoprim resistance. This was true both for total trimethoprim resistance and for trimethoprim mono-resistance. The distributions of E. coli phenotypes, dfr-genes and E. coli sequence types were stable. The marginal effect on resistance rates was explained by a low fitness cost of trimethoprim resistance observed in vitro and the high levels of associated resistance in trimethoprim resistant isolates. Trimethoprim resistance was, although widespread in the E. coli population, more common in certain E. coli sequence types. The distributions of dfr-genes were different in E. coli and K. pneumoniae and between different E. coli sequence types. These results indicate mechanisms related to the genetic back-bone of E coli to be important for the acquisition and persistence of antibiotic resistance. The findings of this thesis indicates that, at least for some classes of antibiotics, we may have overestimated the usefulness of a strategy for reversing antimicrobial resistance based on the fitness cost of resistance. We have equally underestimated the conserving effects of associated resistance. The stability of the dfr-genes and E. coli sequence types underlines the importance of associated resistance and successful lineages in the spread and maintenance of antibiotic resistance in E. coli.

Cytomegalovirus (CMV) is a β-herpesvirus that, after primary infection, establishes a life-long persistence in the human host. Up to 90% of humans are infected with CMV, that is kept under control by CMV-specific CD8+ and CD4+ T cells. In patients with an impaired cellular immunity, however, CMV infections can be life-threatening. Thus, it is vital to identify risk factors and target high-risk patients. In this thesis we have evaluated low-dose valacyclovir prophylaxis in renal transplant patients and studied CMV-specific T cell immunity in healthy and renal transplant patients. In renal transplant patients, the CMV serostatus of both the recipient (R) and the donor (D) has a major impact on the risk of developing CMV disease. In the high-risk D+/R- population, &gt;50% are likely to develop CMV disease in the absence of prophylaxis and/or pre-emptive therapy. We have used low-dose valacyclovir prophylaxis for high-risk renal transplant patients, and graft and patient survival up to 5 years after transplantation was comparable to data reported for other prophylactic protocols. The incidence of CMV disease and graft rejection during the first year after transplantation was also comparable to that achieved with other protocols, and without the adverse effects reported for other therapies. In the D+/R+ population, with a 15-35% risk of developing CMV disease, it is important to identify those individuals that are subject to a higher risk because of risk factors other than CMV serostatus. We therefore measured several immunologic parameters in renal transplant patients and in immunocompetent individuals with latent and primary CMV infection. In patients with a primary symptomatic CMV infection, CMV-specific CD8+ T cells peaked within a month after onset of symptoms but declined rapidly. In renal transplant patients, we found that the reduction in IFNγ-producing CMV-specific CD4+ T cells at 2 months post-transplantation may predict high-grade CMV DNAemia.