ASTMH 64th Annual Meeting. October 25-29, 2015 Philadelphia Marriott Downtown Philadelphia, Pennsylvania USA / Acute respiratory infections (ARI) are the main cause of morbidity and mortality in children under 5 years worldwide. Bordetella pertussis is a highly contagious bacterium that can cause serious illness, and approximately half of infected infants less than 1 year old are hospitalized. Also, pertussis immunization series is not completed until six months of age, leaving young infants vulnerable to pertussis. In Peru, pertussis is an increasing health problem despite immunization efforts, and the role of B. pertussis in ARI is unknown. We determined the prevalence of B. pertussis among children under 5 years old admitted to Hospital Nacional Cayetano Heredia in Lima with diagnosis of ARI between Jan-2009 and Dec 2010. Epidemiological and clinical features were collected, and presence of B. pertussis was determined by PCR (pertussis toxin and IS481 gene). A total of 596 nasopharyngeal samples among children under 5 years were analyzed. In 114 (19.1%) samples were positive for B. pertussis. 32.5% of sample positive to B. pertussis were diagnosed as viral pneumonia at diagnosis. Importantly, 71.9% of cases were under 12 months of age and 58.8% have been contact with other ARI infected people. Significant differences in clinical symptoms between the total ARI cases and B. pertussis cases were not found. The most frequent symptoms in B. pertussis cases were fever (100%), rhinorrhea 78%, cough 71.9% and respiratory distress 60.5%. One child died due to the infection. B. pertussis cases showed a seasonal distribution with peaks during the months March June and November. This study shows the high prevalence of B. pertussis in infants who were hospitalized due to severe acute respiratory infections in Lima, Peru. Epidemiologic surveillance programs for B. pertussis are essential in the future in Peru

joruiz@clinic.ub.es / Objective: To characterize two Achromobacter xylosoxidans recovered from 2 patients diagnosed with pertussis during a Bordetella pertussis surveillance program. Methods: Nasopharyngeal swabs from 2 children under 1 year of age with clinical suspicion of pertussis were analyzed by culture and PCR. Results: Two Achromobacter xylosoxidans A8, closely related to Bordetella spp. were recovered from 2 patients diagnosed of pertussis, both carrying the ptxA gene and IS418 the pertussis toxin encoding gene. Subsequently, antibiotic susceptibility was evaluated by disk-diffusion method and by PCR. Conclusions: Although more detailed studies are needed, the present data highlight the possibility that Achromobacter xylosoxidans, closely related Bordetella pertussis microorganisms and not covered under the vaccine umbrella, might also result in cases of whooping cough. Thereby further surveillance is necessary to determine the extension and relevance of their pathogenic role in order to discriminate their real public health implication.

Dissertation submitted to the Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, in fulfillment of the requirements for the degree of Master of Science in Medicine. Johannesburg, 2015 / Pertussis, caused by Bordetella pertussis, is a vaccine-preventable disease affecting persons of all ages. Despite vaccination with either the whole-cell or acellular vaccine, the burden of pertussis has increased worldwide. The acellular vaccine was licensed in South Africa in 2009, replacing the whole-cell vaccine; however, due to no active surveillance, pertussis is underestimated in this country. This study describes the burden of disease caused by B. pertussis and other Bordetella species in patients with severe respiratory illness (SRI), influenza-like illness (ILI) and controls. Prospective, active surveillance was conducted amongst SRI and ILI patients and controls at two sentinel sites in South Africa. Patients who met the case definitions were enrolled from May 2012 to October 2014. Clinical and demographic data were collected. Induced sputum was collected from SRI patients only and combined nasopharyngeal/oropharyngeal specimens were collected from all patients and controls. Real-time polymerase chain reaction (PCR) was used to target the insertion sequences IS481, pIS1001, hIS1001 and pertussis toxin gene ptxS1. All data were analysed in Microsoft Excel (Microsoft Corporation). Statistical significance was determined using the chi-squared test and univariate logistic regression at p <0.05 for all parameters. Of 8569 cases that were enrolled and tested, 118 [1.4%, 118/8569 (95% CI 1.1 – 1.6)] were positive for B. pertussis of which 2% [80/3982 (95% CI 1.6 – 2.5)] presented with SRI, 1% [32/3243 (95% CI 0.7 – 1.4)] with ILI and 0.4% [6/1344 (95% CI 0.2 – 1.0)] were asymptomatic. Positive cases were stratified into confirmed pertussis and probable pertussis based on cycle threshold (Ct) value cut-offs generated by real-time PCR for IS481. Within the SRI population, there were more probable than confirmed pertussis cases [51/3982, 1.3% vs. 29/3982, 0.7%; p=0.02] and within the ILI group there were 0.5% confirmed and probable cases, respectively [15/3243, 0.5% vs. 17/3243, 0.5%; p=0.86]. The highest detection rate of pertussis in SRI positive cases was in the ≥65 year olds (2.8%, 6/208) and for the ILI positive cases the highest detection rate was in the 1-4 year olds (1.5%, 9/614). Pertussis disease was observed mainly in the winter and spring months with a 15% increase in disease detected in August 2014. The B. pertussis attributable fraction was 67% (95% confidence interval [CI] 18.49 – 86.63) for SRI positive cases. Fifty-eight percent (46/80) of B. pertussis positive cases were co-infected with respiratory bacteria (Streptococcus pneumoniae, Haemophilus influenzae, Legionella spp. or Mycoplasma pneumoniae) or viruses (influenza, respiratory syncytial virus (RSV), human metapneumovirus or other viruses (adenovirus, enterovirus, parainfluenza or rhinovirus). HIV status and full pertussis vaccination for age did not affect B. pertussis positivity. B. parapertussis was detected in 1% [40/3982 (95% CI 0.7 – 1.4)] of the SRI population, 0.6% [18/3243 (95% CI 0.3 – 0.9)] of the ILI population and in 0.1% [2/1344 (0.02 – 0.5)] of asymptomatic individuals. The highest detection rate for the SRI (1.6%, 8/497) and ILI (1.5%, 9/614) positive cases were in the 1-4 year olds. The B. parapertussis attributable fraction was 80% (95% confidence interval [CI] 12.52 – 95.38) for SRI cases. Four cases tested positive for B. bronchiseptica, of which one individual was HIV positive. B. pertussis, B. parapertussis and B. bronchiseptica were detected despite the case definitions not being ideal for the detection of these pathogens. Bordetella spp. was detected in all age groups tested. This study generates baseline data for pertussis in South Africa and surveillance is ongoing.

Thèse de doctorat : Sciences de la vie et de la santé. Biologie cellulaire et moléculaires des épithéliums : Paris 12 : 2004. / Version électronique uniquement consultable au sein de l'Université Paris 12 (Intranet). Titre provenant de l'écran-titre. Bibliogr. : 332 réf.

An aspartate transcarbamoylase (ATCase) gene from Bordetella pertussis was amplified by PCR and ligated into pT-ADV for expression in Escherichia coli. This particular ATCase (pyrB) was an inactive gene found adjacent to an inactive dihydroorotase (DHOase) gene (pyrC'). This experiment was undertaken to determine whether this pyrB gene was capable of expression alone or if it was capable of expression only when cotransformed with a functional pyrC'. When transformed into E. coli TB2 pyrB-, the gene did not produce any ATCase activity. The gene was then co-transformed into E. coli TB2 pyrB- along with a plasmid containing the pyrC' gene from Pseudomonas aeruginosa and assayed for ATCase activity. Negative results were again recorded.

Bordetella pertussis, the etiologic agent of whooping cough or pertussis, produces a multitude of virulence factors including a hemolysin. Virulent phase B. pertussis isolates are hemolytic, whereas avirulent isolates are not. Other investigations concerning B. pertussis adenylate cyclase toxin indicate it has hemolytic activity and is a member of the bacterial RTX toxin family. In an attempt to further characterize hemolysis by B. pertussis, a new B. pertussis gene was isolated which conferred a hemolytic phenotype on non-hemolytic E. coli. DNA sequencing of the putative B. pertussis hemolysin gene revealed it encoded a 27 kDa protein similar to HlyX, an FNR-like transcriptional regulator from Actinobacillus pleuropneumonia, which also confers hemolysis upon E. coli. No similarity to bacterial cytolysins was found. The B. pertussis transcriptional regulator-like gene and its encoded protein were named btr and BTR, respectively. BJB1, a BTR deficient B. pertussis strain was constructed. The btr::kan mutation was shown to have no effect on the production, or phenotypic modulation, of hemolysis by B. pertussis. BTR production was not regulated by the BvgA-S two component sensor-regulator. An FNR deficient E. coli, JRG1728 (Δfnr), was transformed with a btr recombinant plasmid pHLY1A. The B. pertussis btr gene complemented the FNR deficient E. coli to grow anaerobically on a non-fermentable carbon source. This suggested that BTR may function as a B. pertussis transcriptional regulator which responds to anoxic conditions.

No description available.

Typescript (photocopy). / Digitized by Kansas Correctional Industries

Background: Pertussis diagnosis may go unrecognized when other pathogens, such as respiratory syncytial virus (RSV) circulate. Methods: A prospective cross-sectional study was conducted in Lima, Peru from January 2009 to September 2010. A total of 596 children under 5 years old admitted with clinical diagnoses of acute respiratory infections were test for B. pertussis and RSV detection by polymerase chain reaction (PCR). Results: The pertussis toxin and IS481 genes were detected in 19.12% (114/596) of the cases and the respiratory syncytial viruses (RSV-A and RSV-B) were identified in 17.28% (103/596) of patients. Infants under 3 months old were the most frequently affected by this pathogens in 43% (49/114) and 35.9% (37/103) respectively. An increase of B. pertussis was observed from February to March and from October to November with a Seasonal index between 1.32-1.51 and 1.24-3.5 respectively. Conclusions: Epidemiologic surveillance for B. pertussis is essential in Peru, especially in children that could most benefit from the vaccine. B. pertussis should be suspected in infants hospitalized for acute respiratory symptoms for early treatment and prevent complications. / Tesis

Bordetella pertussis produces a number of virulence determinants believed to contribute to its survival in the host as well as to the pathogenesis of disease. One of these factors, adenylate cyclase toxin (ACT), has been implicated to penetrate human neutrophils and macrophages and abrogate their function by virtue of unregulated production of intracellular cAMP. In order to adequately study the nature of ACT and its role in pathogenesis, it is necessary to isolate the toxin from other virulence factors produced by the organism. Attempts by other investigators to purify ACT and maintain both its invasive and catalytic properties have not been successful. B. pertussis produces a cell associated ACT during mid-log phase of growth in Stainer-Scholte medium. Purification of ACT with both activities from urea extracted whole cells has been achieved by hydroxylapatite and calmodulin-sepharose chromatography. ACT is a single protein of 220 kd molecular weight with an isoelectric point of 7.0. The protein probably contains regions which are strongly hydrophobic. ACT has a specific activity of nearly 17,000 μM cAMP formed/min. An 850 ng sample of ACT induced over 1,400 pmoles cAMP/10⁶ S49 mouse lymphoma cells while 660 ng of ACT inhibited human neutrophil chemiluminescence by 65%.