OBJECTIVE: The principal objective of this study was to measure various aspects of immunity in children with invasive infections due to Haemophilus influenzae type b and Staphylococcus aureus. These serious infections are a significant cause of childhood morbidity and mortality in all populations and affect healthy as well as compromised children. Evidence suggests that imbalances or deficiencies in certain aspects of immunity such as IgG subclasses, the capacity to make specific subclass antibodies, antibody affinities, complement isotypes, immunoglobulin allotypes or mannose binding protein may place certain children at risk for developing invasive disease. Investigation of these factors in a group of children with infection necessitated that normal ranges be established for children of comparable ages from the same population. A secondary objective of this study has therefore been to establish normal percentiles for the IgG subclasses in age, race and sex matched healthy controls. METHODS: Patients admitted to the Red Cross War Memorial Children's Hospital with septic meningitis due to Haemophilus influenzae type b and osteomyelitis/septic arthritis due to Haemophilus influenzae type b or Staphylococcus aureus formed the study population. Section A of this thesis describes the methods for establishing, validating and standardizing ELISAs for measuring the IgG subclasses (lgGl, IgG2, IgG3 and IgG4) and subclass antibodies specific to Haemophilus influenzae polyribosylribitol phosphate, Staphylococcus aureus teichoic acid and tetanus toxoid. The relative affinity of antibodies in these ELISAs was determined by the incorporation of diethylamine (DEA). In order to determine the immunoglobulin allotypes ELISAs were developed to measure the G1m(f), G2m(n) and Km(3) allotypes. The frequency of these allotypic markers in the different ethnic groups was established. The relationship between immunoglobulin allotypes and IgG subclass values were investigated in both patient and control groups. RESULTS: ELISA assays to measure IgG subclasses; IgG, IgG 1 and IgG4 tetanus toxoid antibodies; IgG, IgG 1 and IgG2 H. influenzae type b polyribosylribitol phosphate capsular polysaccharide antibodies; IgG, IgG1 and IgG2 S. aureus teichoic acid antibodies and G1m(f), G2m(n) and Km(3) allotypes were successfully established. Where possible the assays were standardized with reference sera and specimens were exchanged with international laboratories. Age, race and sex related percentile charts and tables of normal ranges for IgG and IgG subclasses of Black and Coloured children were established. The IgG and IgG 1 values were higher than those previously reported for children in developed countries. Black children with H. influenzae meningitis had significantly lower IgG 1, IgG2 and IgG3 levels compared to the controls and although similar trends were seen for IgG and IgG4 levels they were not statistically significant. Coloured children with H. influenzae meningitis and Coloured and Black children with H. influenzae osteomyelitis/septic arthritis also showed a similar tendency of lower IgG and IgG subclass levels than the controls but these trends were also not significantly different. All patients responded to tetanus toxoid antigen suggesting normal immunocompetence to protein antigens. H. influenzae type b capsular polysaccharide antibodies were low in children with H. influenzae type b meningitis and osteomyelitis/septic arthritis and did not increase during the illness. IgG and IgG 1 teichoic acid antibodies were raised in patients with S. aureus osteomyelitis/septic arthritis although no further rise in these antibodies was seen when measured several weeks after the illness. The antibody affinity ELISAs showed that IgG 1 tetanus toxoid antibody had a greater affinity than IgG4 tetanus toxoid antibody, the IgG 1 and IgG2 H. influenzae capsular polysaccharide antibodies were of similar affinity and the IgG 1 teichoic acid antibody was of higher affinity than the IgG2 antibody. The G1m(f) and G2m(n) positive allotypes were uncommon in Black but common in the Coloured populations whereas Km(3) was common in both groups. There was a significantly decreased frequency of the G2m(n) positive allotype in Coloured patients with H. influenzae type b meningitis and H. influenzae type b osteomyelitis/septic arthritis which was not found in patients with S. aureus osteomyelitis/septic arthritis. In both Coloured and Black children with H. influenzae meningitis there was a significantly decreased frequency of the Km(3) allotype. No differences in C4 isotypes and mannose binding protein levels were evident in the patient and control groups. CONCLUSION: This study has developed simple, specific and reproducible ELISAs to measure IgG subclasses and subclass antibodies specific to tetanus toxoid, H. influenzae polyribosylribitol phosphate and S. aureus teichoic acid. Age, sex and race related normal ranges for IgG subclasses in the local Black and Coloured populations have been established. Black children with H. influenzae type b meningitis had significantly lower IgG 1, IgG2 and IgG3 levels compared to the controls. There was a clear association between a decrease of the G2m(n) allotype and the Km(3) allotype and susceptibility to invasive infections caused by H. influenzae.

Nosocomial outbreaks of infection due to non-typeable Haemophilus influenzae (NTHi) are rarely described. There are a few published reports that suggest that elderly patients with underlying pulmonary disease are at risk and that person-to-person spread is key to disease transmission. During the summer months of 2005, we documented an outbreak of NTHi infections in a Veterans Affairs nursing home. Thirteen patients developed conjunctivitis or lower respiratory infection involving a β-lactamase-negative biotype III NTHi isolate, with an indistinguishable SmaI macrorestriction pattern. Patients were elderly males usually with underlying cardiac and pulmonary disease. A case-control study failed to demonstrate any specific significant risk factor for NTHi infection and there was no evidence of spatial clustering of cases within the nursing home. A random throat culture survey involving nursing home patients during the outbreak showed that only one of 19 persons was colonized with NTHi. The outbreak concluded following appropriate treatment and an emphasis on universal and respiratory droplet precautions. All patients recovered and a specific inciting event for the outbreak was never defined. Literature review revealed a spectrum of responses to nosocomial NTHi infections and a lack of consensus regarding the infection control approach towards NTHi outbreaks.

No description available.

Made available in DSpace on 2015-07-22T20:49:40Z (GMT). No. of bitstreams: 0 Previous issue date: 2010-06-30 / Introdução: Apesar de relatos sobre a Atenção Integrada às Doenças Prevalentes na Infância (AIDPI) melhorar a assistência à saúde da criança até cinco anos, não são identificados estudos direcionados ao componente peri-neonatal dessa estratégia. Objetivo: avaliar, após a capacitação em AIDPI Neonatal, o conhecimento e a percepção de médicos e enfermeiros quanto à assistência à gestante e à criança do nascimento até os dois meses de vida, e sua aplicabilidade prática em uma região da Amazônia. Método: estudo de coorte constituída de 31 médicos e 61 enfermeiros provenientes de 24 municípios, que participaram de sete capacitações em seis Pólos Regionais de Saúde no interior do Pará, Amazônia, realizado de abr/2006 a dez/2008. O estudo foi conduzido em duas fases, consistindo a 1ª fase na aplicação presencial de cinco questionários antes (T1) e imediatamente após 24 horas (T2) de capacitação em AIDPI Neonatal, conforme diretrizes da OPAS em 2007, adaptadas ao nosso meio. A 2ª fase compreendeu a aplicação presencial dos mesmos questionários aos 92 profissionais, em média 16 (14-20) meses após a 1ª fase (T3). Os questionários abordaram dados demográficos dos profissionais em T1, o conhecimento sobre assistência à gestante, reanimação neonatal, puericultura e doenças até dois meses em T1, T2 e T3, além da avaliação da capacitação em T2 e da percepção das condições de assistência no município e no local de prática clínica em T1 e T3. Para estimar as diferenças entre os tempos e as categorias profissionais foram criados escores de zero (inadequação completa) a 100 (adequaçãocompleta) comparados por meio da análise de variância com medidas repetidas. Resultados: os 92 profissionais caracterizaram-se por ser do sexo feminino (83%), nascidos (74%) e graduados (79%) no Pará, atender crianças duas ou mais vezes por semana (86%) e possuir pós-graduação (63%). Os médicos eram graduados há 17 (1-35) anos e os enfermeiros há nove (0-31) anos (p<0,001). Os primeiros relataram maior atuação em pediatria, e qualificação específica, com residência ou especialização, do que os últimos. Observou-se variação do conhecimento de acordo com o tempo (T1, T2 e T3) e a profissão (médicos>enfermeiros: p<0,001). Entre T1 e T2 constatou-se acréscimo deconhecimento dos profissionais sobre a assistência à gestante (p=0,026), reanimação neonatal (p<0,001), puericultura (p<0,001) e doenças até dois meses (p<0,01). Tal conhecimento perdurou, no mínimo, após 16 meses da capacitação nas áreas de reanimação neonatal (p=0,028) e doenças até dois meses (p<0,001). A capacitação teve avaliação positiva dos profissionais (94%) que perceberam melhora na prática clínica no seu local de trabalho (p<0,001), porém sem relato de alteração nas condições de saúde do município (p=0,066) entre T1 e T3. Conclusão: os médicos e enfermeiros apresentaram acréscimo, no mínimo por 16 meses, no conhecimento sobre a assistência à gestante e à criança até dois meses, além de perceberem melhora em sua condição de prática clínica após a capacitação em AIDPI Neonatal. Essa capacitação pode servir de modelo a ser aplicado em outras regiões com semelhante contexto epidemiológico / Objective: to assess knowledge and perception of professionals about care of pregnant women and children to two months of life, after training in Neonatal Integrated Management of Childhood Illness (IMCI), and its practical applicability in the Amazon Region. Method: a cohort study comprising 92 professionals who participated in seven Neonatal IMCI training courses in Para, from April/2006 to December/2008. Five questionnaires were applied face-to-face before (T1) and 24h (T2) after training in Neonatal IMCI (PAHO, 2007), and 16 (14-20) months after training (T3). Scores ranging from zero (complete inappropriateness) to 100 (complete appropriateness) were compared by ANOVA with repeated measures. Results: Time since graduation was 17y (1-35) for physicians and 9y (0-31) for nurses (p<0.001). Variation of knowledge was observed according to time and profession (physicians>nurses: p<0.001). Between T1 and T2, enhanced knowledge was verified in care of pregnant women (p=0.026), neonatal resuscitation (p<0.001), neonatal and infant care (p<0.001) and diseases up to two months (p<0.01). Such knowledge was observed at least for 16 months in neonatal resuscitation (p=0.028) and diseases up to two months (p<0.001). The capacity-building was positively evaluated by professionals (94%), who perceived improvement in clinical practice (p<0.001), without report of change in health conditions of the city (p=0.066) between T1 and T3. Conclusion: Training in Neonatal IMCI enhanced knowledge about care of pregnant women and infants up to two months, in addition to acknowledging better clinical practice for physicians and nurses. This training can be a model to be applied in other regions with similar epidemiological context. / TEDE / BV UNIFESP: Teses e dissertações

Charles University First Medical Faculty Study programme: History of Medicine Summary of dissertation The Spanish Flu Pandemic 1918/19 with particular reference to the Bohemian Lands and Central European relations Dr. med. univ. Harald Salfellner Prague, 2017 Summary Towards the end of the First World War, in 1918 and 1919, humanity faced a previously unparalleled flu pandemic; within a few months, more people had been killed than in all the battles of the 1914-18 war put together. The precise number of victims is unknown but is today generally reckoned at between 20 and 50 million. The whole world was affected by the Spanish flu, with the exception of a few remote islands, and Europe, already bled to death by industrialised warfare, was particularly hard hit. In summer 1918, the pandemic reached Bohemia in an early, relatively benign wave. A few weeks later, thousands were struck down in Prague in a second and far more deadly phase of the illness. In October 1918, as the First Czechoslovakian Republic arose from the ashes of the multiethnic Austrian state, and the masses celebrated in the cities, thousands of feverish patients were coughing behind drawn curtains, and facing an uncertain fate. In the USA, the flu pandemic - the greatest health disaster of the 20th century - has been the subject of many...

<p>Acute otitis media (AOM) is a common disease in childhood and is one of the most common causes for outpatient antibiotic treatment. The major aetiological agents of AOM have varied over the decades. Now the three most common pathogens are <i>Streptococcus pneumoniae</i>, <i>Haemophilus influenzae</i> and <i>Moraxella catarrhalis</i>. The resistance patterns of these organisms have also varied from the beginning of the antibiotic era to the situation we have today with an increasing incidence of penicillin-resistant <i>S. pneumoniae</i> and a moderate to high frequency of beta-lactamase production in <i>H. influenzae</i> and <i>M. catarrhalis</i>. In Sweden we have continued to use the Scandinavian treatment policy of penicillins as the first-line antibiotic treatment of AOM, which has been implemented with good results in the past. The question is if this policy will continue to have acceptable treatment results.</p><p>In order to investigate aspects of treatment, protection and structural changes in AOM, an animal model was used.</p><p>Amoxicillin treatment of AOM caused by <i>H. influenzae</i> was studied. Amoxicillin treatment was shown to shorten the duration of the infection and to reduce the morphological changes normally observed after an untreated AOM. The influence of antibiotic treatment on recurrent AOM was evaluated. Amoxicillin treatment did not lead to less protection against reinfection. Abstaining from antibiotics did not improve the levels of serum IgG antibodies. The IgG levels were significantly higher in treated animals after rechallenge. AOM caused by <i>H</i>. <i>influenzae</i> with a non-beta-lactamase-mediated resistance to beta-lactams was investigated and it was observed that during amoxicillin treatment the chromosomal changes mediating resistance were possibly advantageous for the bacterium. In cultures from children with AOM, there is sometimes growth of several bacteria. The possibility of a sheltering effect of beta-lactamase-producing <i>H. influenzae</i> on a penicillin-sensitive <i>S. pneumoniae</i> in a mixed infection was investigated, and amoxicillin was shown to eradicate the pneumococci from the middle ear despite the presence of beta-lactamase. An increasingly cultured bacterium in nasopharynx and in AOM is <i>M. catarrhalis</i>. It is now beta-lactamase-producing in almost 100% of cases and is thus not eradicated by penicillins. An animal model of AOM caused by beta-lactamase-producing <i>M. catarrhalis</i> was established to study the course of this infection with the possibility of evaluating aspects of virulence between AOM pathogens. The AOM observed was a self-limiting disease.</p><p>The results obtained in this study in a rat model support the continuing use of penicillins as first-line drugs in the treatment of AOM. Penicillins are not sufficient to treat all causative agents, but the majority of pathogens including the most virulent bacteria are eradicated from the middle ear. </p>

DNA mismatch repair ensures faithful transmission of genetic material from parents to progeny, which is required for the survival of the organism. The studies on E. coli MMR proteins have formed the basis for the study of the MMR system in eukaryotic organisms, because the functions of MMR proteins believed to be been conserved. In organisms that harbor MutH protein, it is known that MutH acts as a monomer which nicks the unmethylated daughter strand and is activated in a MutS-MutL- dependent manner. The cleavage specificity of MutH is very stringent. Till recently, it was not clear as to how MutH distinguishes hemimethylated DNA from fully or unmethylated DNA. The co-crystal structures of MutH-DNA complexes revealed that Y212, R184 and P185 were in close proximity to the methyl-adenine. Clustal-W sequence alignment of MutH with Sau3AI showed that Sau3AI has PCT residues instead of L183, R184, and P185. A triple mutant MutH-L183P-R184C-P185T was found to cleave both unmethylated and methylated DNA. The nicking endonuclease activity of the LRP→ PCT triple mutant was enhanced in the presence of Haemophilus influenzae MutL. The mutL gene of Neisseria gonorrhoeae was cloned and the gene product purified. It was shown that the homodimeric Neisseria gonorrhoeae MutL (NgoL) protein displays an endonuclease activity that incises covalently closed circular DNA in the presence of manganese or magnesium or calcium ions unlike human MutLα which shows endonuclease activity only in the presence of manganese. Further more the C-terminal domain of Neisseria gonorrhoeae MutL (NgoL-CTD) consisting of amino acids 460 to 658 also exhibits Mn2+ dependent endonuclease activity. Sedimentation velocity, sedimentation equilibrium and dynamic light scattering experiments show NgoL-CTD to be a dimer. By in vitro comparison of wild-type and a mutant NgoL-CTD protein, it was shown that the latter protein exhibits highly reduced endonuclease activity. Surface plasmon resonance spectroscopy was used to determine the kinetics of DNA binding by NgoL. The DNA binding was carried out in absence of metal ions. Interaction studies with NgoL with ssDNA in SPR spectroscopy revealed a KD value of 4.7 × 10–8 M. While the human MutLα endonuclease activity was shown to be stimulated by ATP, ATP inhibits NgoL endonuclease activity. By in vitro comparison of wild-type and a mutant NgoL-CTD protein, it was shown that the latter protein exhibits highly reduced endonuclease activity. NgoL ATPase activity was enhanced in the presence of DNA. The fact that NgoL ATPase activity is stimulated ~ 2.5-fold by dsDNA and ~ 2-fold by ssDNA is a further evidence for the interaction between NgoL and DNA. The results presented above show that NgoL harbors a nicking endonuclease activity which is present in the C-terminal domain. NgoL and NgoL-CTD are dimers in solution and DMHA(X)2E(X)4E motif present in the CTD is required for the nicking endonuclease activity. These results suggest that DNA mismatch repair mechanism in N. gonorrhoeae is different from that in E. coli. In the absence of MutH homolog, N. gonorrhoeae is able to repair the DNA by virtue of MutL nicking endonuclease activity.

Acute otitis media (AOM) is a common disease in childhood and is one of the most common causes for outpatient antibiotic treatment. The major aetiological agents of AOM have varied over the decades. Now the three most common pathogens are Streptococcus pneumoniae, Haemophilus influenzae and Moraxella catarrhalis. The resistance patterns of these organisms have also varied from the beginning of the antibiotic era to the situation we have today with an increasing incidence of penicillin-resistant S. pneumoniae and a moderate to high frequency of beta-lactamase production in H. influenzae and M. catarrhalis. In Sweden we have continued to use the Scandinavian treatment policy of penicillins as the first-line antibiotic treatment of AOM, which has been implemented with good results in the past. The question is if this policy will continue to have acceptable treatment results. In order to investigate aspects of treatment, protection and structural changes in AOM, an animal model was used. Amoxicillin treatment of AOM caused by H. influenzae was studied. Amoxicillin treatment was shown to shorten the duration of the infection and to reduce the morphological changes normally observed after an untreated AOM. The influence of antibiotic treatment on recurrent AOM was evaluated. Amoxicillin treatment did not lead to less protection against reinfection. Abstaining from antibiotics did not improve the levels of serum IgG antibodies. The IgG levels were significantly higher in treated animals after rechallenge. AOM caused by H. influenzae with a non-beta-lactamase-mediated resistance to beta-lactams was investigated and it was observed that during amoxicillin treatment the chromosomal changes mediating resistance were possibly advantageous for the bacterium. In cultures from children with AOM, there is sometimes growth of several bacteria. The possibility of a sheltering effect of beta-lactamase-producing H. influenzae on a penicillin-sensitive S. pneumoniae in a mixed infection was investigated, and amoxicillin was shown to eradicate the pneumococci from the middle ear despite the presence of beta-lactamase. An increasingly cultured bacterium in nasopharynx and in AOM is M. catarrhalis. It is now beta-lactamase-producing in almost 100% of cases and is thus not eradicated by penicillins. An animal model of AOM caused by beta-lactamase-producing M. catarrhalis was established to study the course of this infection with the possibility of evaluating aspects of virulence between AOM pathogens. The AOM observed was a self-limiting disease. The results obtained in this study in a rat model support the continuing use of penicillins as first-line drugs in the treatment of AOM. Penicillins are not sufficient to treat all causative agents, but the majority of pathogens including the most virulent bacteria are eradicated from the middle ear.

Diss. (sammanfattning) Linköping : Linköpings universitet, 2005. / Härtill 5 uppsatser.

Haemophilus influenzae is a pathogenic Gram-negative bacterium that colonizes the upper respiratory tract of humans and can cause otitis media, upper and lower respiratory infections, and meningitis. Factors important for H. influenzae to colonize humans and cause disease are not fully understood. Different bacterial pathogens are armed with virulence mechanisms unique to their specific strategies for interacting with their hosts. Many of the proteins mediating these interactions are secreted and contain disulfide bonds required for function or stability. I postulated that identifying the set of secreted proteins in H. influenzae that require periplasmic disulfide bonds would provide better understanding of this bacterium's pathogenic mechanisms. In this thesis, the periplasmic disulfide bond oxidoreductase protein, DsbA, was found to be essential for colonization and virulence of H. influenzae. Mutants of dsbA were also found to be sensitive to the bactericidal effects of serum. However, the DsbA-dependent proteins important for pathogenesis of this organism have not been previously identified. To find them, putative targets of the periplasmic disulfide bond pathway were identified and examined for factors which might be important for mediating critical virulence aspects. By doing so, novel virulence factors were discovered including those important for heme and zinc acquisition, as well as resistance to complement. Overall, the work presented here provides insight into requirements for H. influenzae to survive within various host environments.