BACKGROUND In this study morphological and molecular characterization of Acanthamoeba strains, isolated from dental unit waterlines (DUWLs) were surveyed and the levels of disinfection achievable in vitro by the application of ozone disinfectant to DUWLs were evaluate. METHODS Water samples were collected from air-water syringes, cup fillers and tap water before and at the end of the working ...

This study examined whether Legionella pneumophila is able to thrive on heat-killed microbial cells (necrotrophy) present in biofilms or heat-treated water systems. Quantification by means of plate counting, real-time PCR, and flow cytometry demonstrated necrotrophic growth of L. pneumophila in water after 96 h, when at least 100 dead cells are available to one L. pneumophila cell. Compared to ...

Nontuberculous mycobacteria (NTM) are environmental bacteria increasingly associated to public health problems. In water systems, free-living amoebae (FLA) feed on bacteria by phagocytosis, but several bacteria, including many NTM, are resistant to this predation. Thus, FLA can be seen as a training ground for pathogenic bacteria. Mycobacterium llatzerense was previously described as frequently...

1. Room-temperature CO-reduced minus reduced difference spectra of intact cells of Acanthamoeba castellanii show the presence of CO-reacting haemoproteins in cells from the early-exponential, late-exponential and stationary phases of growth. 2. The relative rates of reaction with CO of the two haemoproteins differ; that of cytochrome a/a3 with CO is complete within 1 min of bubbling with CO, wh...

Many genes inherited from the alpha-proteobacterial ancestor of mitochondria have undergone evolutionary transfer to the nuclear genome in eukaryotes. In some rare cases, genes have been functionally transferred in pieces, resulting in split proteins that presumably interact in trans within mitochondria, fulfilling the same role as the ancestral, intact protein. We describe a nucleus-encoded mi...

Extracts of Acanthamoeba castellanii were previously known to contain two myosin-like ATPases: Acanthumoeba myosin II, a double-headed enzyme of native molecular weight of about 400,000 comprised of two heavy chains of about 170,000 daltons and two pairs of light chains of about 17,500 and 17,000 daltons; and Acanthxwweba myosin I, a single-headed enzyme of native molecular weight of about 180,...

Differentiat ion of several cell types is inhibi ted by 5-bromodeoxyuridine (BUdR) (1-3, 9, 12). Since B U d R can be incorpora ted into D NA in place of thymidine (TdR) (12), the inhibi t ion of different ia t ion may be due to the presence of B U d R in the DNA of the cell. In Acanthamoeba castellanii, DNA synthesis cont inues t h rough overt different iat ion of the t rophozoite into the d o...

Levels of radioactive glycine and glycerol incorporated into the plasma membrane of Acanthamoeba castellanii during phagocytosis were determined in order to elucidate how surface membrane expended during this process is replaced. The amoebae were allowed to ingest latex beads in the presence of the labelled membrane precursors and plasma membrane was then isolated and analysed for the presence ...

The type III secretion system among Gram-negative bacteria is known to deliver effectors into host cell to interfere with host cellular processes. The type III secretion system in Yersina, Pseudomonas and Enterohemorrhagic Escherichia coli have been well documented to be involved in the bacterial pathogenicity. The existence of type III secretion system has been demonstrated in neuropathogenic ...

Light and phase-contrast microscopic observations of excystment in Acanthamoeba castellanii have been used to classify cells in excysting populations as free trophozoites, or mature, activated, or preemergent cysts. These categories have been used to describe the kinetics of excystment. A pH of 7 and a temperature of 30 degrees C have been found to be optimal for the activation of mature cysts....