Shigella is a genus of highly adapted bacterial pathogens that cause bacillary dysentery in humans. Bacteria reaching the colon invade intestinal epithelial cells by process bacterial-directed endocytosis mediated Ipa proteins: IpaB, IpaC, and IpaD Shigella. The invasion thought to be receptor-mediated phenomenon, although cellular components host interact with proteins have not yet been identified. We report here flexneri invasive system Chinese hamster ovary (CHO) cell monolayers, were...

Intracellular replication of Brucella requires the VirB complex, which is highly similar to conjugative DNA transfer systems. In this study, we show that internalizes into macrophages by swimming on cell surface with generalized membrane ruffling for several minutes, after bacteria are enclosed macropinosomes. Lipid raft-associated molecules such as glycosylphosphatidylinositol (GPI)-anchored proteins, GM1 gangliosides and cholesterol were selectively incorporated macropinosomes containing...

The products of the Legionella pneumophila dot/icm genes enable bacterium to replicate within a macrophage vacuole. This study demonstrates that Dot/Icm machinery promotes macropinocytotic uptake L. into mouse macrophages. In strains harboring permissive Lgn1 allele, promoted formation vacuoles were morphologically similar macropinosomes and dependent on presence an intact system. Macropinosome appeared occur during, rather than after, closure plasma membrane about bacterium, since...

The genetic determinants required for invasion of epithelial cells by Shigella flexneri and the subsequent bacterial spreading are encoded large virulence plasmid. Expression genes is under control various on plasmid as well chromosome. We previously identified one virulence-associated loci near phoBR in NotI-C fragment chromosome S. 2a YSH6000 designated locus vacC. vacC mutant showed decreased levels IpaC, IpaD proteins transcription ipa, an operon essential (N. Okada, C. Sasakawa, T....

The products of the Brucella abortus virB gene locus, which are highly similar to conjugative DNA transfer system, enable bacterium replicate within macrophage vacuoles. replicative phagosome is thought be established by interaction a substrate VirB complex with macrophages, although and its host cellular target have not yet been identified. We report here that Hsp60, member GroEL family chaperonins, B. capable interacting directly or indirectly prion protein (PrPC) on cells. Aggregation...

During 2012–2013, a total of 4325 host-seeking adult ticks belonging to the genus Ixodes were collected from various localities Hokkaido, northernmost island Japan. Tick lysates subjected real-time PCR assay detect borrelial infection. The was designed for specific detection Relapsing fever spirochete Borrelia miyamotoi and unspecific Lyme disease-related spirochetes. Overall prevalence B. 2% (71/3532) in persulcatus, 4.3% (5/117) pavlovskyi 0.1% (1/676) ovatus. I. persulcatus significantly...

Brucella abortus is a Gram-negative bacterium causing brucellosis. Although B. known to infect via the oral route, entry site in gastrointestinal tract has been unclear. We found that was selectively internalized by microfold cells (M cells), subset of epithelial specialized for mucosal Ag uptake. During this process, colocalization cellular prion protein (PrP(C)) and evident on apical surface as well subapical vacuolar structures M cells. Internalization PrP(C)-deficient (Prnp(-/-)) mice...

ABSTRACT Mycoplasma pneumoniae causes pneumonia, tracheobronchitis, pharyngitis, and asthma in humans. The pathogenesis of M. infection is attributed to excessive immune responses. We previously demonstrated that lipoproteins induced inflammatory responses through Toll-like receptor 2 (TLR2). In the present study, we strong macrophages derived from TLR2 knockout (KO) mice. Cytokine production KO was increased compared with wild-type (WT) Heat-killed, antibiotic-treated, overgrown failed...

Secretion of IpaB, IpaC, and IpaD proteins Shigella flexneri, essential for the invasion epithelial cells, requires a number encoded by spa mxi loci on large plasmid. Introduction dsbA::Tn5 into S.flexneri from Escherichia coli K-12 reduced invasiveness, which resulted decrease in capacity to release external medium. Examination surface-presented Ipa dsbA mutant, however, revealed at levels similar those wild-type cells. Since defective phenotype was that spa32 mutant S. flexneri Spa32...

Shigella, the causative agents of bacillary dysentery, are capable invading mammalian cells that not normally phagocytic. Uptake bacteria by is directed bacterial factors named IpaB, IpaC, and IpaD invasins, in which Ipa invasins secreted into environment can interact with alpha5beta1 integrin. We report here Shigella invasion epithelial requires rho activity, a ras-related GTP-binding protein. The invasive capacity flexneri for Chinese hamister ovary (CHO) other were greatly reduced when...

Bacillus anthracis enters the body as an endospore, and encapsulation toxin production occur after germination. Capsule is proposed to be antiphagocytic factor, induces cytokine for systemic shock. The dep gene, adjacent cap region encapsulation, degrades high–molecular weight capsule (H-capsule) lower–molecular (L-capsule), which releases into culture supernatant. This study analyzed biological function of cap-dep region. null mutant Sm-1, formed H-capsule but not L-capsule, was avirulent....

Aims: To detect and isolate Bacillus anthracis from the air by a simple rapid procedure. Methods Results: One hundred litres of were filtered through an monitor device. After membrane was suspended in PBS, spores B. added. The suspension plated on cereus selective agar (BCA) plates to colonies. also heated at 95°C for 15 min used real‐time PCR using Light Cycler system anthrax‐specific primers. Conclusions: A single cell detected within 1 h isolated BCA plate two d. Significance Impact...

Brucella spp. are facultative intracellular pathogens that have the ability to survive and multiply in professional nonprofessional phagocytes, cause abortion domestic animals undulant fever humans. The mechanism factors of virulence not fully understood. High-affinity zinc uptake system protein mutant (znuA mutant) showed reduced growth chelated medium, failed replicate HeLa cells mouse bone marrow-derived macrophages. Transformation znuA with a shuttle vector pBBR1MCS-4 containing gene...

Abstract Background The mechanisms of abortion induced by bacterial infection are largely unknown. In the present study, we investigated Brucella abortus , a causative agent brucellosis and facultative intracellular pathogen, in mouse model. Results High rates were observed for on day 4.5 gestation, but not other days. Regardless whether fetuses aborted or stayed alive, transmission bacteria into fetus replication placenta observed. There was higher degree colonization than organs many...

ABSTRACT Brucella spp. are facultative intracellular pathogens that have the ability to survive and multiply in professional nonprofessional phagocytes cause abortion domestic animals undulant fever humans. The mechanism factors of virulence not fully understood. To identify genes related internalization multiplication host cells, abortus was mutagenized by mini-Tn 5 Km2 transposon carryied kanamycin resistance gene, 4,400 mutants were screened, HeLa cells infected with each mutant....

A novel virulence gene ( virA ) was identified upstream of the virG on large plasmid Shigella flexneri 2a YSH6000. Characterization mutants infecting MK2 epithelial cell monolayers revealed that their invasive capacity decreased to less than one fifth wild‐type level. Nevertheless, bacteria were capable expressing and secreting IpaB, IpaC IpaD proteins. The also impaired in ability spread intercellularly, since gave rise a small number foci focus‐plaque‐forming test with cells. Although...

Some public areas in Japan such as parks and gardens can be highly contaminated with pigeon feces. We examined levels of four bacterial contaminations fecal samples from feral pigeons 7 prefectures. isolated Salmonella Typhimurium S. Cerro 17 (3.9%) 436 samples, well Mycobacterium spp. including M. avium-intracellulare complex 29 (19.0%) 153 samples. The polymerase chain reaction detected Chlamydia psittaci C. pecorum 106 (22.9%) 463 but E. coli O-157 was not any the Our results indicate...

Generation of an abnormal isoform the prion protein (PrP(Sc)) is a key aspect propagation prions. Elucidation intracellular localization PrP(Sc) in prion-infected cells facilitates understanding cellular mechanism propagation. However, technical improvement PrP(Sc)-specific detection required for precise analysis. Here, we show that mAb 132, which recognizes region adjacent to most amyloidogenic PrP, useful by immunofluorescence assay pre-treated with guanidine thiocyanate. Extensive...

Abstract Legionella pneumophila , the causative agent of Legionnaires’ disease, replicates within alveolar macrophages and free-living amoebae. However, lifestyle L. in environment remains largely unknown. Here we established a novel natural host model endosymbiosis using ciliate Paramecium caudatum . We also identified endosymbiosis-modulating factor A (LefA), which contributes to change life stage from lysis, enabling escape environment. isolated strains they exhibited cytotoxicity toward...

ABSTRACT Brucella abortus is an intracellular pathogen that uses a crafty strategy to invade and proliferate within host cells, but the distinct signaling pathways associated with phagocytic mechanisms of B. remain unclear. The present study was performed test hypothesis Toll-like receptor 4 (TLR4)-linked interacting Janus kinase 2 (JAK2) plays essential role in phagocytosis by macrophages. effects TLR4-JAK2 on murine macrophage RAW 264.7 cells were observed through infection assay confocal...

ABSTRACT Brucella abortus is a facultative intracellular bacterium capable of surviving inside macrophages. Intracellular replication B. requires the VirB complex, which highly similar to conjugative DNA transfer systems. In this study, we show that plasma membrane cholesterol macrophages required for VirB-dependent internalization and also contributes establishment bacterial infection in mice. The was accelerated by treating with acetylated low-density lipoprotein (acLDL). Treatment acyl...

ABSTRACT The ability of the complete genome sequence enterohemorrhagic Escherichia coli O157 led to identification a 17-kb chromosomal region which contained type III secretion system gene cluster at min 64.5. This locus contains open reading frames whose amino acid sequences show high degrees similarity with those proteins that make up apparatus, is encoded by inv-spa-prg on Salmonella SPI-1 pathogenicity island. was designated ETT2 ( E. 2) and consisted epr , epa eiv genes. found in...