Diss. (sammanfattning) Uppsala : Sveriges lantbruksuniv. / Härtill 4 uppsatser.

: Filamentous hemagglutinin (FHA) is adhesive protein molecule that is secreted by Gram- negative bacterium Bordetella pertusis, the causative agent of whooping cough (pertussis). The C-terminal segment of FHA plays a crucial role in host-pathogen interaction, however, the structural features are still unknown. Here, we identified the C-terminal residue of FHA and processed form of FHA (FHA*) as alanine residues in position 2304 and 2228, respectively. Circular dichroism (CD) and nuclear magnetic resonance (NMR) spectroscopy demonstrated that the C-terminal segment of FHA(FHA 1995-2228) is characterized by alpha-helical contribution without any compact protein fold. Moreover, suppression of transcription of small regulatory RNA pairing to the 5'-end of fhaB transcript resulted in two- fold increase of FHA production. These data suggested that the C-terminal segment of FHA appear to be an unstructured protein and FHA secretion is negatively regulated by small regulatory RNA. (In Czech) Keywords: Bordetella pertussis, filamentous hemagglutinin, small RNA

The Gram-negative pathogen bacterium Bordetella pertussis is the infectious agent causing pertussis or whooping cough. The infection is dangerous to infants, often being deadly if untreated. Since whole-cell pertussis vaccines have been replaced by acellular pertussis vaccines, pertussis has become the most prevalent vaccine-preventable disease in developed countries. Therefore, the development of a new generation of pertussis vaccines has become a high priority. Opsonophagocytic assays are one method used to assess the efficacy of new vaccines. The main objective of the thesis is to develop opsonophagocytic killing and uptake assays for the measurement of functional antibody activity against Bordetella pertussis. Neutrophils from mice and humans were isolated by three different methods and used for the assessment of different human and mouse sera in opsonophagocytic killing and uptake assays. Different experimental conditions were tested, including multiplicity of infection and serum dilutions. The opsonophagocytic uptake assay proved to discriminate between naïve and immune sera. Serum from mice vaccinated with the whole-cell pertussis vaccine enhanced opsonophagocytic uptake of B. pertussis cells into neutrophils, while serum from mice immunized with the acellular pertussis vaccine did not....

Pertussis is an infectious disease caused by the Gram-negative bacterium Bordetella pertussis. In Peru, actual public health programs indicate that vaccination against B. pertussis must be mandatory and generalized, besides all detected cases must be reported. The objective of this study was to determine the prevalence of B. pertussis among children under five years of age with a presumptive diagnosis of whopping cough in Cajamarca, a region located in northern Peru. / Background and Objectives: Pertussis is an infectious disease caused by the Gram-negative bacterium Bordetella pertussis. In Peru, actual public health programs indicate that vaccination against B. pertussis must be mandatory and generalized, be-sides all detected cases must be reported. The objective of this study was to determine the prevalence of B. pertussis among children under five years of age with a presumptive diagnosis of whopping cough in Cajamarca, a region located in northern Peru. Materials and Methods: The population of this cross-sectional study were children under 5 years old hospitalized as presumptive cases of pertussis during December 2017 to December 2018. The nasopharyngeal samples were analyzed by real-time PCR for the detection of B. pertussis. Results: B. pertussis was identified as PCR + in 42.3% of our sample (33/78). The clinical presentation that was observed most frequently includes paroxysmal coughing (97%), difficulty breathing (69.7%), cyanosis (72.7%) and post-tussive em-esis (60.6%). Additionally, pneumonia was the most observed complication (33.3%). Four of the patients with PCR+ for B. pertussis presented only lymphocytosis, five only leukocytosis, two patients with decreased leukocytosis and lymphocytes and only one patient with leukopenia and relative lymphocytosis. There was a percentage of 84.8% of unvaccinated children in the PCR+ group. Finally, the mother was the most frequent symptom carrier (18.2%). Conclusion: In conclusion, in the studied population there is a high rate of PCR+ cases for B. pertussis. Laboratory values may show leukopenia or lymphopenia in patients with pertussis. It is necessary to use appropriate laboratory diagnostic tests in all infants with respiratory symptoms for B. pertussis. Since, the clinical diagnosis overestimates the diagnosis of pertussis. / Revisión por pares

Background: Acute respiratory infections (ARIs) represent an important cause of morbidity and mortality in children, remaining a major public health concern, especially affecting children under 5 years old from low-income countries. Unfortunately, information regarding their epidemiology is still limited in Peru. Methods: A secondary data analysis was performed from a previous cross-sectional study conducted in children with a probable diagnosis of Pertussis from January 2010 to July 2012. All samples were analyzed via Polymerase Chain Reaction (PCR) for the following etiologies: Influenza-A, Influenza-B, RSV-A, RSV-B, Adenovirus, Parainfluenza 1 virus, Parainfluenza 2 virus, Parainfluenza 3 virus, Mycoplasma pneumoniae and Chlamydia pneumoniae. Results: A total of 288 patients were included. The most common pathogen isolated was Adenovirus (49%), followed by Bordetella pertussis (41%) from our previous investigation, the most prevelant microorganisms were Mycoplasma pneumonia (26%) and Influenza-B (19.8%). Coinfections were reported in 58% of samples and the most common association was found between B. pertussis and Adenovirus (12.2%). Conclusions: There was a high prevalence of Adenovirus, Mycoplasma pneumoniae and other etiologies in patients with a probable diagnosis of pertussis. Despite the presence of persistent cough lasting at least two weeks and other clinical characteristics highly suspicious of pertussis, secondary etiologies should be considered in children under 5 years-old in order to give a proper treatment. / Revisión por pares

Objective: This study aimed to determine the prevalence of A. baumannii in children aged less than 1 year admitted with a clinical diagnosis of whooping cough. Results: A total of 225 nasopharyngeal samples from children under 1 year old hospitalized with clinical diagnosis of whooping cough were studied from January 2010 to July 2012. The presence of A. baumannii was detected in 20.89% (47/225) of the nasopharyngeal swab samples. Among the 47 patients with A. baumannii: 5 were diagnosed with A. baumannii monoinfection, 17 co-infection with bacteria, 7 co-infection with virus and 18 co-infection with bacteria + virus. It was observed that 51.6% (116/225) were children between 29 days and 3 months old, this same group had the highest overall prevalence with 53.3%. The most common co-infecting pathogens were Bordetella pertussis in 55.3%, Adenovirus in 42.6% and Mycoplasma pneumoniae in 23.4%. / Revisión por pares

Background and Objectives: Pertussis is an infectious disease caused by the Gram-negative bacterium Bordetella pertussis. In Peru, actual public health programs indicate that vaccination against B. pertussis must be mandatory and generalized, be-sides all detected cases must be reported. The objective of this study was to determine the prevalence of B. pertussis among children under five years of age with a presumptive diagnosis of whopping cough in Cajamarca, a region located in northern Peru. Materials and Methods: The population of this cross-sectional study were children under 5 years old hospitalized as presumptive cases of pertussis during December 2017 to December 2018. The nasopharyngeal samples were analyzed by real-time PCR for the detection of B. pertussis. Results: B. pertussis was identified as PCR + in 42.3% of our sample (33/78). The clinical presentation that was observed most frequently includes paroxysmal coughing (97%), difficulty breathing (69.7%), cyanosis (72.7%) and post-tussive em-esis (60.6%). Additionally, pneumonia was the most observed complication (33.3%). Four of the patients with PCR+ for B. pertussis presented only lymphocytosis, five only leukocytosis, two patients with decreased leukocytosis and lymphocytes and only one patient with leukopenia and relative lymphocytosis. There was a percentage of 84.8% of unvaccinated children in the PCR+ group. Finally, the mother was the most frequent symptom carrier (18.2%). Conclusion: In conclusion, in the studied population there is a high rate of PCR+ cases for B. pertussis. Laboratory values may show leukopenia or lymphopenia in patients with pertussis. It is necessary to use appropriate laboratory diagnostic tests in all infants with respiratory symptoms for B. pertussis. Since, the clinical diagnosis overestimates the diagnosis of pertussis. / Revisión por pares

Mittels Tissue Engineering hergestellte humane 3D in vitro-Testsysteme sind ein neuer Ansatz, um u.a. Erkrankungen der Atemwege zu simulieren und zu untersuchen. Obwohl gegen B. pertussis, den Erreger des Keuchhustens, Impfstoffe zur Verfügung stehen, nimmt die Erkrankungs-Inzidenz in den letzten Jahren deutlich zu. Da B. pertussis zu den obligat humanpathogenen Erregern zählt, sind die aus Tierversuchen stammenden Daten nur unzureichend auf den Menschen übertragbar. Die genauen Pathomechanismen der Infektion sind bisher nicht geklärt. Auf einer biologischen Kollagenmatrix wurde eine Ko-Kultur aus humanen tracheobronchialen Fibroblasten und humanen tracheobronchialen Epithelzellen (hTEC) angesiedelt und 3 Wochen unter apikaler Belüftung kultiviert. Die ausdifferenzierten 3D Testsysteme wurden mit Überständen von Bordetella pertussis-Kulturen inkubiert und auf licht- und elektronenmikroskopischer Ebene analysiert. Weiterhin wurden 2D Kulturen der hTEC mit Hilfe der Ramanspektroskopie nicht-invasiv auf intrazelluläre Veränderungen nach der Inkubation mit den bakteriellen Überständen untersucht. Das 3D Testsystem der humanen Atemwegschleimhaut zeigte auf lichtmikroskopischer und ultrastruktureller Ebene eine hohe in vitro – in vivo-Korrelation. Die elektronenmikroskopische Analyse zeigte morphologische Veränderungen nach der Inkubation mit den B. pertussis Überständen, die mit vorbeschrieben Effekten einer B. pertussis Infektion korrelieren. Mittels der Ramanspektroskopie ließen sich Gruppen von unbehandelten Zellen von Gruppen, die zuvor mit Bakterienüberständen inkubiert wurden, trennen. Somit zeigte sich die Ramanspektroskopie sensitiv für intrazelluläre Infektionsfolgen. Zusammenfassend wurde belegt, dass das 3D-Modell der humanen Atemwegschleimhaut zur Untersuchung obligat humanpathogener Infektionserreger geeignet ist und dass die Ramanspektroskopie eine nicht-invasive Methode ist, um durch Infektionen hervorgerufene intrazellulären Pathologien zu analysieren. / Three dimensional (3D) tissue-engineered human tissue models are of high relevance, e.g. to investigate virulence mechanisms of human obligate pathogens in vitro. One major obligate agent causing acute respiratory diseases is Bordetella pertussis (Bp), the agent of whooping cough. The progress towards elimination Bp has stalled which is mainly caused due to an absence of suitable models to gain more knowledge about its pathomechanism. On a biological collagen matrix (SISser) a co-culture of human fibroblasts and human airway epithelial cells (hTEC) was seeded and cultured under airlift conditions. The completely differentiated test systems were treated with sterile-filtrated supernatants of Bp and afterwards analyzed with light and transmission electron microscopy. 2D cultures of hTEC were also infected and analyzed with Raman spectroscopy. The 3D test system of the human airway mucosa shows high in vitro - in vivo - correlation on both structural and ultrastructural level. Preliminary morphological analysis after infection with Bp supernatant reveals considerable ultrastructural changes which were not observed in control samples and correlate to effects knows from Bp infections in vivo. In 2D cultivation conditions the Raman spectra of infected hTEC clearly differ from spectra of the control. It is shown that the 3D airway mucosa model represents pathological effects of Bp toxins and offers an opportunity to further examine their pathomechanisms. Raman spectroscopy appears to be a practical method to show intracellular changes on living cells non-invasively.

No description available.

No description available.