Natalia A. Kozak

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Legionella longbeachae causes most cases of legionellosis in Australia and may be underreported worldwide due to the lack of L. longbeachae-specific diagnostic tests. L. longbeachae displays distinctive differences in intracellular trafficking, caspase 1 activation, and infection in mouse models compared to Legionella pneumophila, yet these two species have(More)
Bordetella bronchiseptica utilizes a type III secretion system (TTSS) for induction of non-apoptotic cytotoxicity in host cells and modulation of host immunity. The identity of Bordetella TTSS effectors, however, has remained elusive. Here we report a genome-wide screen for TTSS effectors based on shared biophysical and functional characteristics of class I(More)
We have recently described a multicomponent cascade that regulates type III secretion in Bordetella. This cascade includes a group of proteins, BtrU, BtrW, and BtrV, that contain an array of domains that define partner-switching complexes previously characterized in gram-positive bacteria. BtrU contains a PP2C-like serine phosphatase domain, BtrW contains a(More)
BACKGROUND Naegleria fowleri is a climate-sensitive, thermophilic ameba found in the environment, including warm, freshwater lakes and rivers. Primary amebic meningoencephalitis (PAM), which is almost universally fatal, occurs when N. fowleri-containing water enters the nose, typically during swimming, and N. fowleri migrates to the brain via the olfactory(More)
Travel is a risk factor for Legionnaires' disease. In 2008, two cases were reported in condominium guests where we investigated a 2001 outbreak. We reinvestigated to identify additional cases and determine whether ongoing transmission resulted from persistent colonization of potable water. Exposures were assessed by matched case-control analyses (2001) and(More)
Approximately 84% of legionellosis cases are due to Legionella pneumophila serogroup 1. Moreover, a majority of L. pneumophila serogroup 1 clinical isolates react positively with monoclonal antibody 2 (MAb2) of the international standard panel. Over 94% of the legionellosis outbreaks investigated by the Centers for Disease Control and Prevention are due to(More)
Legionella is ubiquitous in freshwater systems worldwide and can also be found in soil. Legionellosis may be caused by inhalation of aerosolized water or soil particles containing Legionella. Isolation of Legionella from the environment is an essential step in outbreak investigation and may also be performed within the context of a hazard analysis and(More)
We investigated a mixed outbreak of Legionnaires' disease (LD) and Pontiac fever (PF) at a military base to identify the outbreak's environmental source as well as known legionellosis risk factors. Base workers with possible legionellosis were interviewed and, if consenting, underwent testing for legionellosis. A retrospective cohort study collected(More)
Members of the Gram-negative genus Legionella are typically found in freshwater environments, with the exception of L. longbeachae, which is present in composts and potting mixes. When contaminated aerosols are inhaled, legionellosis may result, typically as either the more serious pneumonia Legionnaires' disease or the less severe flu-like illness Pontiac(More)
BACKGROUND During a Legionnaires' disease (LD) outbreak, combined epidemiological and environmental investigations were conducted to identify prevention recommendations for facilities where elderly residents live independently but have an increased risk of legionellosis. METHODS Survey responses (n = 143) were used to calculate attack rates and describe(More)
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