Arto Tapio Pulliainen

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A plethora of pathogenic viruses colonize bats. However, bat bacterial flora and its zoonotic threat remain ill defined. In a study initially conducted as a quantitative metagenomic analysis of the fecal bacterial flora of the Daubenton's bat in Finland, we unexpectedly detected DNA of several hemotrophic and ectoparasite-transmitted bacterial genera,(More)
Bartonella spp. are facultative intracellular bacteria that typically cause a long-lasting intraerythrocytic bacteremia in their mammalian reservoir hosts, thereby favoring transmission by blood-sucking arthropods. In most cases, natural reservoir host infections are subclinical and the relapsing intraerythrocytic bacteremia may last weeks, months, or even(More)
Bartonella henselae (Bh) is a worldwide distributed zoonotic pathogen. Depending on the immune status of the infected individual this bacterium can cause a wide spectrum of clinical manifestations, ranging from cat scratch disease (CSD) to bacillary angiomatosis (BA) and bacillary peliosis (BP). BA and BP are characterized by tumor-like lesions at the skin(More)
Scavenger receptors are innate immune molecules recognizing and inducing the clearance of non-host as well as modified host molecules. To recognize a wide pattern of invading microbes, many scavenger receptors bind to common pathogen-associated molecular patterns, such as lipopolysaccharides and lipoteichoic acids. Similarly, the gp340/DMBT1 protein, a(More)
H(2)O(2) is an unavoidable cytotoxic by-product of aerobic life. Dpr, a recently discovered member of the Dps protein family, provides a means for catalase-negative bacteria to tolerate H(2)O(2). Potentially, Dpr could bind free intracellular iron and thus inhibit the Fenton chemistry-catalyzed formation of toxic hydroxyl radicals (H(2)O(2) + Fe(2+) -->(More)
Streptococcus pyogenes (group A streptococcus [GAS]), a catalase-negative gram-positive bacterium, is aerotolerant and survives H2O2 exposures that kill many catalase-positive bacteria. The molecular basis of the H2O2 resistance is poorly known. Here, we demonstrate that serotype M49 GAS lacking the Rgg regulator is more resistant to H2O2 and also(More)
Transposon mutagenesis is a powerful technique for generating collections of insertion mutants for genetic studies. This paper describes how phage Mu DNA transposition complexes, transpososomes, can be exploited for gene delivery to efficiently introduce selectable markers to genomes of Gram-positive bacteria. Mu transpososomes were assembled in vitro with(More)
Bartonella grahamii colonizes rodents worldwide and has been detected in questing Ixodes ricinus ticks. Here, the first human B. grahamii infection confirmed by multilocus sequence typing is reported. The route of transmission and clinical picture of the patient are similar to those seen in patients with cat scratch disease, which is typically diagnosed as(More)
Subversion of host organism cAMP signaling is an efficient and widespread mechanism of microbial pathogenesis. Bartonella effector protein A (BepA) of vasculotumorigenic Bartonella henselae protects the infected human endothelial cells against apoptotic stimuli by elevation of cellular cAMP levels by an as yet unknown mechanism. Here, adenylyl cyclase (AC)(More)
The Dps family members constitute a distinct group of multimeric and ferritin-like iron binding proteins (up to 500 iron atoms/12-mer) that are widespread in eubacteria and archaea and implicated in oxidative stress resistance and virulence. Despite the wealth of structural knowledge, the mechanism of iron incorporation has remained elusive. Here, we(More)