No description available.

Schistosomiasis is endemic in the world today, infecting more than 300 million people, mainly in the developing world areas. Diagnosis of the disease in modem man can be achieved by using a wide range of diagnostic tools, such as radiology, histology and the enzyme linked immunosorbent assay( ELISA). As a consequence of the schistosomiasis tissue bank being established at the Manchester Museum as described in Parasitology Today (Contis and David 1996), a need for diagnostic tools that can be applied to ancient tissues has occurred in order to study the epidemiology of this disease. This is not a modern disease as histological work done by Ruffer (1910) and Millet et al (1980) and using ELISA (Deelder et al, 1990) have shown the presence of schistosome eggs and worm antigens respectively in ancient Egyptian tissues.

The literature review highlighted the continuing problem of hospital acquired infection. This study examined this problem in depth, in a high-risk area, the Neonatal Intensive Care Unit. A multi-centre study was conducted using multi-methods in order to capture data regarding nurses' infection control practices in neonatal units. Ninety nurses/ nursery nurses from six neonatal units were included in the study. Non-participant observation was used to investigate nurses' existing infection control practices, interviews were used to explore nurses' opinions of infection control, questionnaires were used to collect demographic data about the sample and assess nurses' knowledge of infection control issues and a Likert-type scale was developed to investigate the unit atmosphere/environment. Microbiological laboratory work was undertaken to compare the efficacies of three products (soap, alcohol hand rub and chlorhexidine) at removing/reducing the numbers of bacteria found on the hands. The effectiveness of gloves at preventing contamination of the hands was also assessed. Finally, the numbers of bacteria recovered from the hands of university administrative staff and nurses were compared to determine whether or not nurses had higher numbers of bacteria on their hands due to the number of organisms they are exposed to and their increased frequency of hand hygiene. Overall, nurses' hand hygiene practices were found to be relatively poor. However, there was some evidence that length of shift, as a proxy indicator of fatigue, and unit atmosphere/environment may influence nurses' infection control practices. Opinions and knowledge were not associated with observed practice. Nursery nurses had lower hand hygiene scores and knowledge scores than nurses and increased experience in the neonatal unit was associated with increased infection control knowledge. The number of bacteria recovered from the hands of nurses was significantly higher than the numbers of bacteria recovered from the hands of administrative staff. In the clinical setting, chlorhexidine was found to be the only product that consistently removed significant numbers of bacteria from the hands. Indeed, the alcohol hand rub was found to increase the numbers of bacteria on the hands. The number of bacteria recovered from the hands did not differ when gloves were worn. This suggests the inside of gloves may be providing a medium for the multiplication of bacteria. However, the number of bacteria recovered from the surface of used gloves was significantly lower than the numbers of bacteria recovered from nurses' hands after nursing activities. The use of gloves for all procedures on the neonatal unit may be advantageous.

No description available.

Sudden Unexpected Nocturnal Deaths (SUND) occur in young immigrant workers, mainly from Southeast Asia employed in countries such as Singapore and Saudi Arabia. Enzyme linked immunosorbent assays (ELISA) and flow cytometry method were developed to screen body fluids and tissues for toxic shock syndrome (TSST-1) and staphylococcal enterotoxins A (SEA), B (SEB) and C (SEC). Both frozen and formalin fixed tissues were obtained from infants who died suddenly and unexpectedly in Scotland, France or Australia. The flow cytometry method detected toxin in both frozen and fixed tissues, but ELSIA was suitable only for frozen tissues or those fixed less than 12 months. TSST-1 and enterotoxins were identified in over half the specimens from infants. Of the 4 samples from SUND victims, one was borderline positive for TSST-1; however the bodies had been stored for extended period prior to autopsy. Human buffy coats were used to examine the effect of IgG to the toxins for neutralising activity and the effect of cortisol. Tumour necrosis factor α (TNF-α) was detected by bioassay with L929 cells, interluekin-6 (IL-6) and interluekin-10 (IL-10) were measured by ELSIA. IL-6 and TNF-α elicited by the toxins were not reduced by night time level of cortisol (5-10 μg dl <SUP>-1</SUP>) levels. Day time levels of cortisol (10-20 μg dl <SUP>-1</SUP>) significantly inhibited IL-6 production but not TNF-α in responses. Stress levels of cortisol (40-80 μg dl <SUP>-1</SUP>) significantly reduced all three cytokines earlier than the normal day time levels. The methods developed for collection of tissue specimens, detection of toxins and quantitative IgG assays for antitoxins can be applied to investigation of SUND victims to test the hypothesis that some of these deaths are precipitated by pyrogenic staphylococcal toxins.

The correlation between stress and increased susceptibility to infectious disease has been widely established. A direct consequence of stress, whether physical or mental, is the release of catecholamine stress hormones (adrenaline and noradrenaline), which as well as reducing immune function, have recently been shown to directly enhance the growth of a variety of Gram positive and Gram negative bacteria. The mechanism of catecholamine-induced growth stimulation involved catecholamines facilitating iron removal from the high affinity mammalian iron binding proteins transferrin and lactoferrin. In the case of Escherichia coli, the direct binding of transferrin was also an important part of this process. However, the precise mechanism(s) by which catecholamines enabled bacterial access to transferrin was not clear, and neither was the identity of the E. coli protein(s) responsible for the binding of transferrin. Using the enteropathogenic E. coli strain E2348/69 as model organism, the objectives of this project were therefore to determine how catecholamines facilitated iron removal from transferrin and lactoferrin, identify and characterise the E. coli transferrin-binding protein, and to investigate globally the effects of catecholamine stress hormones on E. coli growth and virulence. In this study, using a combination of electron paramagnetic resonance spectroscopy, chemical and polyacrylamide gel electrophoresis techniques, it was found that catecholamine stress hormones form a complex with the iron(III) associated with transferrin and lactoferrin, causing its reduction into iron(II), to which these proteins have much lower affinity. This enables the dissociation of iron from transferrin or lactoferrin, which then becomes available for bacterial uptake through ferric or ferrous iron uptake systems. It was also shown that although catecholamines enabled E. coli to acquire iron from transferrin, the amounts of iron made available by the stress hormones, while sufficient to enable growth, the levels of iron actually within the catecholamine-treated bacteria was not enough to switch off the expression of iron-regulated genes. The effects of catecholamines on expression of E. coli proteins was also investigated, and it was found that expression of intimin, important in formation of attaching and effacing lesion, was up-regulated in the presence of catecholamines. Investigation of the role of quorum sensing in the mechanism of E. coli catecholamine responsiveness was also undertaken. Analysing catecholamine responsiveness of a series of E. coli E2346/89 luxS mutants showed that luxS is not required for the ability of E. coli to interact with catecholamine stress hormones.

The prevalence of carbapenem resistance was investigated in <i>A. baumannii</i> strains isolated from diabetic patients in Saudi Arabia. 32% were resistant to imipenem (MIC 16-64 mg/L) and meropenem (MIC 4-64 mg/L). However, all isolates were sensitive to colistin and tigecycline. All isolates were highly resistant (MIC &gt;128mg/L) to all remaining antimicrobial agents used in this study. Eleven imipenem-resistant isolates (MIC 16 – 64 mg/L) possessed the insertion sequence IS<i>Aba1</i>; six of them possess <i>bla</i>_OXA-23 gene, and four also had IS<i>Aba</i>2. One isolate (MIC 16mg/L) had <i>bla</i>_OXA-40 and IS<i>Aba1</i> and one imipenem-sensitive isolate (MIC 0.25mg/L) harboured IS<i>Aba2</i>, IS<i>Aba3</i> and IS<i>18</i>. Twenty-three (61%) of both imipenem-sensitive and resistant isolates had IS<i>Aba1</i> whereas 28 (74%) clinical isolates had <i>bla</i>_ampC.All imipenem-resistant isolates were positive with amplification of the <i>bla</i>_VIMgene by PCR and this was confirmed by sequencing where the gene was confirmed as <i>bla</i>_VIM-2. Ten strains possessed four novel <i>bla</i>_OXA-51-like genes encoding ß–lactamases deposited in the GenBank nucleotide database under accession numbers: EU547443(OXA-90), EU547445 (OXA-130), EU547446 (OXA-131) and EU547447 (OXA-132). The multi-drug-resistance <i>A. baumannii</i> (MdRAB) strains from the diabetic patients showed the highest and broadest growth capabilities, multiplying equally well at critically high glucose levels as well as at low levels. That was in direct comparison with seven control strains, <i>A. baumannii</i> from non diabetics. <i>A. baumannii </i>sensitive strain, MRSA-15, MRSA-16, <i>S. aureus</i>, <i>P. aeruginosa</i> and <i>E. coli</i>. These results suggest that MdRAB has the ability not only to grow successfully in the presence of glucose but also to maintain this capability at all concentrations found within the fluctuating levels of diabetic patients. This suggests the condition of diabetes may preferentially select MdRAB over sensitive strains and also over other multiresistant pathogens. The <i>bla</i>_OXA-23 genes were more frequent (16%) than <i>bla</i>_OXA-40 (2.6%)<i> </i>and no <i>bla</i>_OXA-58were identified. All <i>bla</i>_OXA-23strains also harboured <i>bla</i>_VIM-2enzymes.

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No description available.

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