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Haemophilus influenzae e Haemophilus haemolyticus isolados de crianças que frequentam creches no município de Goiânia-GO: prevalência, fatores de risco e caracterização molecular da resistência antimicrobiana / Haemophilus influenzae and Haemophilus haemolyticus isolates from children who attend day care centers in Goiânia-GO: prevalence, risk factors and molecular characterization of antimicrobial resistanceAlmeida, Robmary Matias de 26 June 2017 (has links)
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Previous issue date: 2017-06-26 / Conselho Nacional de Pesquisa e Desenvolvimento Científico e Tecnológico - CNPq / Haemophilus influenzae (Hi) and Haemophilus haemolyticus (Hhae) are important
microorganisms present in human nasopharyngeal colonization, with rates varying according
to locality, sampling frequency, individual and social factors. Hi is a pathological agent that
causes diseases such as meningitis, pneumonia, sepsis and otitis media, which presents in
encapsulated forms with six serotypes a, b, c, d, e, f, and uncapsulated or non-typeable
(HiNT). Hhae is a nasopharyngeal comensal and rarely causes invasive diseases. The objective
of this study was to estimate the prevalence of Hi and Hhae in children under five years of age
attending public day care centers in the city of Goiânia-GO, to determine the circulating
serotypes, to analyze the risk factors associated with the nasopharyngeal carrige, as well as
to characterize the antimicrobial resistance of Hi. Were analyzed 1.188 nasopharynx swabs
from healthy children between 36 and 59 months of age from October to December 2010. The
samples were submitted to bacterial culture for the isolation of Haemophilus spp. For the
identification of the species, the Real-Time Polymerase Chain Reaction (TR-PCR) was used.
Serotyping, as well as detection of the bla TEM-1 and bla ROB-1 resistance genes, was performed
through the conventional Polymerase Chain Reaction. Phenotypic detection for β-lactamase
production was performed by the chromogenic cephalosporin test. The database was
constructed with the statistical software SPSS (Chicago, IL, USA) version 18.0. Risk factors,
children aged 3 years, low maternal schooling and three or more children under 10 years of
age living in the same household of the child recruited in the study were evaluated by
multivariate Poisson regression. The prevalence of Hi carriers was 54.4% (646 / 1.188), 0.9%
(n = 11) of the serotype e, 0.9% (n = 11) of serotype f, 0.2% (n = 2) serotype a, 0.08% (n
= 1) serotype d, 0.0% (n = 0) serotype b and c and 52.3% (621 / 1.188) of HiNT. The
prevalence of Hhae was 1.2% (14 / 1.188). Among the encapsulated Hi, the prevalence of the
bla TEM-1 gene was 4.0% (1/25) and the bla ROB-1 gene was 4.0% (1/25). Among the 20%
(124/621) of HiNT analysed, the prevalence of the bla TEM-1 gene was 13,7% (17/124) and the
prevalence of the bla TEM-1 gene was 1,6% (2/124). Continuous surveillance of Haemophilus
spp. as a colonizer, is necessary to evaluate its transmission and dissemination in the
population where there is a higher risk of invasive disease, to control Hib re-emergence after
the vaccinacion and to continue to monitor antimicrobial resistance. / Haemophilus influenzae (Hi) e Haemophilus haemolyticus (Hhae) são importantes
microrganismos presentes na colonização nasofaríngea humana, com taxas que variam de
acordo com a localidade, frequência de amostragem, fatores individuais e sociais. O Hi é um
agente patológico causador de doenças como meningite, pneumonia, sepse e otite média que
se apresenta sob as formas capsuladas com seis sorotipos a, b, c, d, e, f, e não capsuladas ounão tipáveis (HiNT). O Hhae é comensal nasofaríngeo e raramente causa doenças invasivas. O
objetivo do estudo foi estimar a prevalência de Hi e Hhae em crianças menores de cinco anos
de idade que frequentam creches públicas no município de Goiânia-GO, determinar os
sorotipos circulantes, analisar os fatores de risco associados ao portador nasofaríngeo, bem
como caracterizar a resistência antimicrobiana dos Hi. Foram analisados 1.188 swabs de
nasofaringe de crianças saudáveis entre 36 e 59 meses de idade, no período de outubro a
dezembro de 2010. As amostras foram submetidas à cultura bacteriana para o isolamento do
Haemophilus spp. Para identificação da espécie foi utilizada a Reação em Cadeia da
Polimerase em Tempo Real (PCR-TR). A sorotipagem, assim como a detecção dos genes de
resistência bla TEM-1 e bla ROB-1 , foi realizada através da Reação em Cadeia da Polimerase
convencional. A detecção fenotípica para produção da β-lactamase foi executada pelo teste da
cefalosporina cromogênica. A base de dados foi construída com o programa estatístico SPSS
(Chicago, IL, USA) versão 18.0. Os fatores de risco, crianças com idade de 3 anos, baixa
escolaridade da mãe e três ou mais crianças menores de 10 anos de idade convivendo no
mesmo domicilio da criança recrutada no estudo, foram avaliados por regressão de Poisson
multivariada. A prevalência de portador do Hi foi de 54,4% (646/1.188) sendo 0,9% (n=11)
do sorotipo e, 0,9% (n=11) do sorotipo f, 0,2% (n=2) do sorotipo a, 0,08%(n=1) do sorotipo
d, 0,0% (n=0) dos sorotipos b e c e 52,3% (621/1.188) de HiNT. A prevalência do Hhae foi
de 1,2% (14/1.188). Entre os Hi encapsulados a prevalência do gene bla TEM-1 foi de 4,0%
(1/25) e do gene bla ROB-1 foi de 4,0% (1/25). Em 20% (124/621) dos HiNT, a prevalência do
gene bla TEM-1 foi de 13,7% (17/124) e do gene bla ROB-1 de 1,6% (2/124). A vigilância contínua
do Haemophilus spp. como colonizador, se faz necessária para avaliar sua transmissão e
disseminação na população onde há maior risco de incidência de doenças invasivas, controlar
a re-emergência do Hib após a vacinação e continuar monitorando a resistência
antimicrobiana.
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Utvärdering av Copan EswabTM för viabilitet av bakterier / Evaluation of Copan Eswab™ for viability of bacteriaHannu, Olof, Hagman, Leonardo January 2017 (has links)
Bakterier har alltid haft en stor inverkan på mänskligheten. För att diagnostisera bakteriella sjukdomar och behandla dem krävs identifiering av bakterien eller bakteriens relevanta egenskaper. Transportmedium har utvecklats för att hålla bakterierna vid liv från provtagning till analys. Syftet med studien var att utvärdera bakteriers viabilitet i det vätskebaserade mediet Copan Eswab jämfört med kolmedium (Copan swab). Bakterierna som ingick i studien var Campylobacter jejuni, Streptococcus pneumoniae, Haemophilus influenzae, Niesseria gonorrhoeae och Fusobacterium nucleatum. Förutom jämförande mellan medierna genomfördes en jämförelse mellan Eswab i kyl och i rumstemperatur. Resultaten för H. influenzae (n=9) och N. gonorrhoeae (n=9) visade att Eswab gav lika många eller fler överlevande bakterier. Gällande F. nucleatum (n=9) visade resultaten att fler överlevde i Copan swab (Copanpinnar) de första 28 timmarna, men även att bakterien inte klarar mer än 28 timmar i rumstemperatur. Gällande S. pneumoniae (n=9) och C. jejuni (n=9) gav båda opålitliga svar. Ytterligare mätpunkter och studier krävs för att erhålla mer pålitliga resultat gällande hur länge bakterierna överlever i Eswab. / Bacteria have always had a great influence on mankind. To diagnose any bacterial disease and treat it it’s necessary to identify the bacteria or any relevant attributes. Different types of specimen transport have been developed to keep the bacteria alive from sampling until the analysis is performed. The purpose of the study was to evaluate the viability of bacteria in the fluid-based media Copan EswabTM compared with charcoal medium (Copan swab). Bacteria included in the study were: Campylobacter jejuni, Streptococcus pneumoniae, Haemophilus influenzae, Niesseria gonorrhoeae and Fusobacterium nucleatum. The study also tried to compare how bacteria survived in Eswab which was refrigerated and in Eswab room temperature. Results for H. influenzae (n=9) and N. gonorrhoeae (n=9) showed that an equal amount or more of the bacteria survived in Eswab. More of F. nucleatum (n=9) survived in Copan swab (Copan swab sticks) for the first 28 hours, additionally they showed that the bacteria won’t survive more than 28 hours in room temperature. Regarding S. pneumoniae (n=9) and C. jejuni (n=9) both displayed unreliable results. Overall more measurements and additional studies are needed for more reliable results.
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Métodos alternativos de purificação do polissacarídeo capsular de Haemophilus influenzae tipo b. / Alternative methods for purification of capsular polysaccharide produced by Haemophilus influenzae type b.Silvia Maria Ferreira Albani 02 February 2009 (has links)
Haemophilus influenzae tipo b é uma bactéria Gram-negativa, patogênica causadora de meningites em crianças. A cápsula polissacarídica (PSb) é o principal fator de virulência e é usado como antígeno vacinal. O método clássico de purificação do PSb envolve várias etapas de precipitação com etanol, fenol e detergente catiônico (inflamável, corrosivo e tóxico), e etapas de ultracentrifugação. O objetivo deste estudo foi substituir total ou parcial as precipitações e/ou uso das centrífugas por cromatografia, digestão enzimática, microfiltração e ultrafiltração tangencial. As cromatografias de troca iônica e de filtração em gel não apresentaram boas purificações, entretanto a hidrofóbica pode eliminar as proteínas contaminantes. As precipitações com etanol foram necessárias para obter a pureza requerida. O etanol de alguma forma favoreceu a ação enzimática e facilitou a posterior ultrafiltração. A separação com etanol em fibra-oca de microfiltração tangencial mostrou melhores purificações do que a centrifugação, mas com uso repetido verificou-se redução na eficiência. / Haemophilus influenzae type b is Gram-negative pathogenic bacterium cause meningitis in children. The capsular polysaccharide (PSb) is the main virulence factor and it is used as vaccine antigen. The classical PSb purification process includes ethanol, phenol and cationic detergent precipitations (explosion prone, corrosive, toxic) and ultracentrifugation steps. The aim of this work was to replace total or partial ethanol precipitations steps and/or elimination of centrifugation by chromatography methods, enzymatic digestion and ultrafiltration (UF) or microfiltration. The results have showed that ion exchange chromatography and gel filtration did not result in good purification, however the hydrophobic can be used for proteins elimination. The ethanol precipitation steps are necessary to achieve the required purity of PSb. In some way ethanol contributed for enzymes action and further improvements in the UF. The ethanol separation with hollow fiber microfiltration exhibited better purification than centrifugation, but after some uses the efficiency has reduced.
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Estabelecimento de um meio quimicamente definido para desenvolvimento de Haemophilus influenzae tipo b e produção de polissacarídeo capsular. / Establishment of a chemically defined medium for development of Haemophilus influenzae type b and capsular polysaccharide production.Paola Rizzo de Paiva 28 September 2016 (has links)
Haemophilus influenzae b (Hib) é uma bactéria patogênica causadora de pneumonia e meningite. Sua cápsula polissacarídica (PRP) é considerada como principal fator de virulência e utilizada como antígeno vacinal. Hib é fastidioso e requer micronutrientes para seu desenvolvimento. A finalidade deste trabalho é estabelecer o meio quimicamente definido para desenvolvimento de Hib e produção de PRP. Inicialmente, definiu-se um meio a partir de dados da literatura. Este meio foi estudado através do delineamento de Plackett-Burman de 44 ensaios, obtendo-se valores máximos de DO540nm de 5,0 UA, e 227,7 mg/L de PRP. A análise estatística revelou que EDTA, NH4Cl, Cys e PVA podem ser removidos do meio sem impactar os parâmetros estudados e que Glm, Hipoxantina, Inosina, Tiamina, Hemina e Tween 80 apresentam efeito significativo positivo para produção de PRP. Analisando os meios estudados, foi possível verificar que a composição do E44 possibilitou produzir o PRP a US$ 16,50/g, sendo considerado o meio quimicamente definido estabelecido neste trabalho. / Haemophilus influenzae b (Hib) is a pathogenic bacterium that causes pneumonia and meningitis. Its capsular polysaccharide (PRP) is considered as a major virulence factor and used as vaccine antigen. Hib is fastidious and requires micronutrients for its development. The purpose of this study is to establish the chemically defined medium for Hib development and PRP production. Initially, a medium was defined based in the literature. This medium was studied by the Plackett-Burman design of 44 trials, achieving maximum values of DO540nm of 5.0 AU and 227.7 mg / L of PRP. Statistical analysis revealed that EDTA, NH4Cl, Cys and PVA can be removed from the medium without impacting the parameters studied and Glm, Hypoxanthine, Inosine, Thiamine, Tween 80 and Hemin exhibit significant positive effect on the PRP production. Analyzing the studied media, it was possible to verify that the composition of E44 enabled to produce PRP to $ 16.50/g, being considered the chemically defined medium established in this work.
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A Novel, Molybdenum-Containing Methionine Sulfoxide Reductase Supports Survival of Haemophilus influenzae in an In vivo Model of InfectionDhouib, Rabeb, Othman, Dk. Seti Maimonah Pg, Lin, Victor, Lai, Xuanjie J., Wijesinghe, Hewa G. S., Essilfie, Ama-Tawiah, Davis, Amanda, Nasreen, Marufa, Bernhardt, Paul V., Hansbro, Philip M., McEwan, Alastair G., Kappler, Ulrike 14 November 2016 (has links)
Haemophilus influenzae is a host adapted human mucosal pathogen involved in a variety of acute and chronic respiratory tract infections, including chronic obstructive pulmonary disease and asthma, all of which rely on its ability to efficiently establish continuing interactions with the host. Here we report the characterization of a novel molybdenum enzyme, TorZ/MtsZ that supports interactions of H. influenzae with host cells during growth in oxygen-limited environments. Strains lacking TorZ/MtsZ showed a reduced ability to survive in contact with epithelial cells as shown by immunofluorescence microscopy and adherence/invasion assays. This included a reduction in the ability of the strain to invade human epithelial cells, a trait that could be linked to the persistence of H. influenzae. The observation that in a murine model of H. influenzae infection, strains lacking TorZ/MtsZ were almost undetectable after 72 h of infection, while similar to 3.6 x 10(3) CFU/mL of the wild type strain were measured under the same conditions is consistent with this view. To understand how TorZ/MtsZ mediates this effect we purified and characterized the enzyme, and were able to show that it is an S- and N-oxide reductase with a stereospecificity for S-sulfoxides. The enzyme converts two physiologically relevant sulfoxides, biotin sulfoxide and methionine sulfoxide (MetSO), with the kinetic parameters suggesting that MetSO is the natural substrate of this enzyme. TorZ/MtsZ was unable to repair sulfoxides in oxidized Calmodulin, suggesting that a role in cell metabolism/energy generation and not protein repair is the key function of this enzyme. Phylogenetic analyses showed that H. influenzae TorZ/MtsZ is only distantly related to the Escherichia colt TorZ TMAO reductase, but instead is a representative of a new, previously uncharacterized Glade of molybdenum enzyme that is widely distributed within the Pasteurellaceae family of pathogenic bacteria. It is likely that MtsZ/TorZ has a similar role in supporting host/pathogen interactions in other members of the Pasteurellaceae, which includes both human and animal pathogens.
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Streptococcus pneumoniae and haemophilus influenzae type B carriage in infants presenting to Zola Community Health Centre for routine immunizationMbelle, Nontombi Marylucy 23 May 2014 (has links)
Acute respiratory tract infections are the most common cause o f illness and death in the
pediatric population worldwide. It is estimated that 70 - 80% o f severe pneumonias in Africa
are caused by S.pnewnoniae (the pneumococcus) followed by H. influenzae type b.
Surveillance reveals that drug resistance is increasing worldwide, South Africa not being an
exception. This has considerably complicated the management o f infections caused by both
the pneumococcus and H. influenzae type b ( H ib ).
It is widely accepted that colonization of the nasopharynx even briefly precedes middle ear
infection and invasive pneumococcal disease. Early onset of colonization after birth has been
associated with early onset o f middle ear infections. Furthermore, colonized children are
able to transmit these organisms to other children.
Carriage o f pneumococci commonly occurs in young children. The carriage of resistant
pneumococci is usually limited to those serotypes carried in children. N ew conjugate
vaccines may be able to reduce colonization o f these serotypes.
This study was undertaken to determine the serotypes and susceptibility o f pneumococci and
H. influenzae type b, and the proportion o f healthy children colonized at Zola Community
Health Centre (ZCHC) in Soweto.
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Salivary IgA responses during the first two years of life: a study of aboriginal and non-aboriginal childrenKyaw-Myint, Su Mon, N/A January 2003 (has links)
Nontypeable Haemophilus influenzae (NTHi), Streptococcus pneumoniae and
Moraxella catarrhalis are common bacterial agents of otitis media which is a major
cause of morbidity in young children. Mucosal immune responses are an integral part
of the immune defense against middle ear infection and it is known that certain
populations, including Australian Aboriginal children, are highly susceptible to disease.
The current study focussed on the development of the mucosal immunity to the three
bacterial pathogens in Aboriginal and non-Aboriginal children from birth to two years
of age, living in the Kalgoorlie-Boulder region of Western Australia. Salivary and
breast milk IgA levels were measured by the enzyme Linked immunosorbent assay. The
measured IgA levels, combined with socio-economic, demographic and bacteriological
data were analyzed statistically to determine the influential factors on the mucosal IgA
response in these children over time.
This study found that each antigen-specific IgA examined followed a distinct ontogeny
pattern and IgA responses differed significantly according to age, indigenous status and
feeding type. Indoors smoke exposure, maternal smoking, and sibling day care
attendance had some impact on salivary IgA levels in the children. However, household
crowding and the presence of older siblings had the most significant impact on salivary
IgA levels for children of different age groups. These two factors were correlated to
increased nasophayrngeal colonization by H. influenzae, S. pneumoniae and M.
catarrhalis and colonization status was also found to influence salivary IgA levels in the
children. No correlation between maternal breast milk IgA levels and child salivary IgA
levels was observed.
The results suggest that the degree of exposure to environmental factors rather than
immunological deficit is responsible for the observed differences in salivary IgA
responses between Aboriginal and non-Aboriginal children and modifying these factors
could lead to a reduction in the burden of otitis media experienced by the children.
Further studies correlating specific salivary IgA levels to diseases such as otitis media
will reveal the role of specific salivary IgA responses in the prevention of infection by
respiratory pathogens.
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Immunological and structural characterisation of the nontypeable Haemophilus influenzae vaccine protein OMP26Kunthalert, Duangkamol, n/a January 2004 (has links)
Nontypeable Haemophilus influenzas (NTHi) is recognised as a significant human
pathogen causing mild to severe respiratory tract infections. At present, no vaccine is
available for prevention of infection caused by this pathogen. Several outer membrane
proteins (OMPs) of NTHi and its lipooligosaccharide have been investigated as possible
vaccine antigens against NTHi infections. Previous investigations in our laboratory
have shown that OMP26 from an NTHi 289 strain was able to significantly enhance
pulmonary clearance of NTHi in a rat model in which animals were immunised via
intestinal Peyer's patches and then boosted intratracheally (Kyd and Cripps, 1998; El-
Adhami et al., 1999). In recent studies, the OMP26, when used as a parenteral
immunogen, was also highly effective at inducing immune responses that led to
significantly enhanced clearance of the chinchilla nasopharynx (Kyd et al., 2003).
These studies indicate significant potential of the OMP26 as a candidate vaccine antigen
and warrant further investigations for development of a vaccine against NTHi.
This thesis focussed on the immunological and structural characterisation of the NTHi
vaccine candidate, OMP26. Peptides of OMP26 were used as tools to localise the
immunologically important regions of the OMP26. Two different E. coli expression
systems, the GST gene fusion and the 6xHis tagged systems, were employed to
construct the OMP26 peptides. It was found in this study that, despite efforts to
optimise the system, the GST-fusion protein system failed to produce consistent results
for the purification and storage of the OMP26 peptides. In contrast, the 6xHis tagged
system exhibited more reliable outcomes in the production of the recombinant OMP26
peptides and the stability of the stored purified peptides. As such, the purified OMP26
peptides from the 6xHis tagged system were chosen to map major regions of
immunological significance for the OMP26 protein.
The regions of the OMP26 which are involved in the induction of the acquired immune
responses have been identified in the present study. Based on the antigen specific
lymphocyte proliferation assay, the dominant T cell epitopes for OMP26 were located
between amino acid residues 95 and 197 (T3+T4 region). These identified T cell
epitopes exhibited the capability of efficient T cell activation, suggesting that the
epitopes within the T3+T4 region potentially had the highest affinity for binding to the
MHC molecules than did any other OMP26 region. Using two different assay systems,
ELISA and BIA, the predominant B cell epitopes of OMP26 were located between
amino acid residues 45 and 145 (T2+T3 region). This region was also found to be
immunodominant across all animal species tested, and with all immunisation regimens
used. Flow cytometry analysis also revealed that these particular epitopes were
expressed on the surface of NTHi cells. By integration of the data obtained from these
current experimental studies and the computational analysis of the OMP26 sequence,
two hypothetical models of the OMP26 were also proposed in this study.
The significant outcomes obtained in this thesis provide a better understanding of the
specificity of the host immune responses to the OMP26 protein These findings provide
great benefit not only for the development of a future NTHi vaccine but for the
development of the peptide-based immunodiagnostic reagents as well. These diagnostic
reagents will be valuable, in particular, for the evaluation of efficacy of an NTHi
vaccine in humans that may include OMP26 or specific conformational structures.
Future studies are still required to further define the minimum epitope length required
for the B and T cell responses identified in this study. The significance of these
responses in immune protection against NTHi infection also requires further
investigations. Human immune responses also need to be determined, but this can only
be achieved following clinical trial studies.
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Phase variable methyltransferases and their role in gene regulation in pathogenic bacteriaStefanie Dowideit Unknown Date (has links)
Previous work carried out in our laboratory has identified that phase variation of type III R-M systems found in Haemophilus influenzae, Neisseria meningitidis and N. gonorrhoeae is reversible, and occurs at high frequency, as seen both through mod::lacZ fusions, and by measuring changes in repeat tract length. In addition, phase variation of the methyltransferases results in coordinated switching of expression of a distinct group of genes in each of the strains studied so far. WE have termed this phenomenon the PHASEVARION, for phase variable regulon, to identify the set of genes whose expression is affected by moe phase variation. Many of the genes found to be regulated by mod phase variation are known virulence factors and even include some genes investigated as candidates for vaccine development (Srikhanta et al., 2005 and 2009. The aims of this project was to further the investigation of how these R-M systems regulated the expression of genes which hitherto had not been predicted to phase vary. The first step in the process of investigating how phase variable R-M systems influence expression of unrelated genes is to identify the DNA sequences methylated by the methyltransferases of interest. As discussed in Chapter 3, elucidation of the ModA1 methylation target site was in part facilitated by predictions that the phase variable methyltransferase found in H. influenzae strain Rd methylated the same sequence as did HinfIII, isolated from H. influenzae strain Rf. This hypothesis was confirmed by methylation dependent inhibition of digestion, revealing that ModA1 methylates the second A in its recognition sequence, 5’-CGAAT-3’. Once confirmed, the genes found to be regulated by modA1 phase variation in the initial phasevarion study could be investigated for the presence of ModA1 methylation sites within their promoters or upstream of their transcriptional regulators. Two such methylation target sites were located just upstream of the dnaK ORF. Transcriptional start site analysis of the dnaK gene revealed three transcripiotnal start sites, one of which is unduced by heat shock. Exactly 10 nucleotides upstream of this heat shock induced transcriptional start site lies one of these ModA1 methylation target sequences. Ongoing invetigations are looking into the importance of this ModA1 site located within the dnaK promoter, and whether this is the site responsible for ModA1 dependent variations in dnaK expression. Although numerous methods were investigated for their potential to identify all sites methylated by the different modA alleles, the only method which resulted in identification of any methylation target sites was methylation dependent inhibition of restriction. This method allowed us to confirm the ModA1 recongition sequence, and to discover the methylation sequence, and adenine targeted by the modA13 allele, which is found in many clinically relevant N. gonorrhoeae strains. As will be discussed in Chapter 5, ModA13 dependent inhibition of restriction was first observed when the Neisserial plasmid pCmGFP was extracted from modA13 ON and modA13::kan cells, and further investigated and confirmed using a Southern blot approach to determine whether ModA13 dependent inhibtion could be detected as differential methylation of the chromosome. It was found that ModA13 recognised the sequence 5’-AGAAA-3’, with methylation occurring on the second last A. This sequence was mapped not only to the genes found to be regulated by modA13 phase variation, but also to the entire FA1090 chromosome, and this information will be used in future studies to investigate the direct molecular mechanisms by which modA13 phase variation results in subpopulations with different phenotypes in relation to antimicrobial resistance and biofilm/cell invasion.
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PCR detection of Streptococcus pneumoniae and Haemophilus influenzae in pneumonia patientsAbdeldaim, Guma M. K. January 2009 (has links)
PCR is a rapid, reproducible method for nucleic acid detection. However, this technology displays significant deficiencies when applied in clinical microbiology. This work’s aim was to improve current diagnostics and provide sensitive and quantitative real-time PCRs. Paper I describes the development of a sensitive and specific quantitative real-time PCR for the detection of Streptococcus pneumoniae, based on the Spn9802 DNA fragment. Applied to nasopharyngeal aspirates from 166 pneumonia patients, Spn9802 PCR had a sensitivity of 94% and a specificity of 98%. In Paper II the performance of a ply gene PCR for identification of pneumococcal lower respiratory tract infection (LRTI) was evaluated on bronchoalveloar lavage fluids. At the detection limit 103 genome copies/mL, 89% sensitivity but only 43% specificity was achieved. Paper III shows that S. pneumoniae DNA is detectable in plasma from acutely febrile patients. Sensitivities were low (26-42%) for detection of pneumococcal pneumonia, for bacteraemic pneumococcal pneumonia they were 60-70%. Paper IV describes evaluation of four PCR targets for Haemophilus influenzae detection. A real-time PCR based on the P6 gene was developed and applied to 166 CAP patients, using cut-off of 104 genome copies/mL the assay had a sensitivity of 97% and a specificity of 96%. In paper V, the two real-time PCRs presented in papers I and IV were combined with a PCR for detection of Neisseriae meningitidis. The analytical sensitivity of this multiplex real-time PCR was not affected by using a mixture of reagents and a combined DNA standard (S. pneumoniae/H. influenzae) in single tubes. Applied to 156 LRTI patients, this PCR had sensitivities over 90% for S. pneumoniae and H. influenzae, and specificities of 89% and 96%, respectively. In conclusion, real-time PCR assays are useful for the diagnosis of S. pneumoniae and H. influenzae. They enable detection after antibiotic installation, and quantification increases the etiological specificity of pneumonia.
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