All issues
Volume 70 (2015)
- Issue 4 Pages 365-
- Issue 3 Pages 339-
- Issue 2 Pages 305-
Volume 70, Issue 4
Displaying 1-5 of 5 articles from this issue
- |<
- <
- 1
- >
- >|
-
[in Japanese]2015 Volume 70 Issue 4 Pages 365-367
Published: 2015
Released on J-STAGE: December 03, 2015
JOURNAL FREE ACCESSDownload PDF (909K)
-
Takashi SHIMIZU2015 Volume 70 Issue 4 Pages 369-374
Published: 2015
Released on J-STAGE: December 03, 2015
JOURNAL FREE ACCESSMycoplasmas are smallest organisms capable of self-replication and cause various diseases in human. Especially, Mycoplasma pneumoniae is known as an etiological agent of pneumonia. From 2010 to 2012, epidemics of M. pneumoniae infections were reported worldwide (e.g., in France, Israel, and Japan). In the diseases caused by mycoplasmas, strong inflammatory responses induced by mycoplasmas have been thought to be important. However, mycoplasmas lack of cell wall and do not possess inflammation-inducing endotoxin such as lipopolysaccharide (LPS). We purified inflammation-inducing factors from pathogenic mycoplasmas and identified that they were lipoproteins. Lipoproteins derived from mycoplasmas induced inflammatory responses through Toll-like receptor (TLR) 2. In addition, we demonstrated that cytadherent property of M. pneumoniae played an important role in induction of inflammatory responses. Cytadherent property of M. pneumoniae induced inflammatory responses through TLR2 independent pathway. TLR4, inflammasomes, and autophagy were involved in this TLR2 independent induction of inflammatory responses.View full abstractDownload PDF (1619K) -
Daisuke NAKANE2015 Volume 70 Issue 4 Pages 375-382
Published: 2015
Released on J-STAGE: December 03, 2015
JOURNAL FREE ACCESSBacteria have various way to move over solid surfaces, such as glass, agar, and host cell. These movements involve surface appendages including flagella, type IV pili and other “mysterious” nano-machineries. Gliding motility was a term used various surface movements by several mechanisms that have not been well understood in past few decades. However, development of visualization techniques allowed us to make much progress on their dynamics of machineries. It also provided us better understanding how bacteria move over surfaces and why bacteria move in natural environments. In this review, I will introduce recent studies on the gliding motility of Flavobacteium and Mycoplasma based on the detail observation of single cell and its motility machinery with micro-nano scales.View full abstractDownload PDF (2340K) -
Yoshikazu FURUTA2015 Volume 70 Issue 4 Pages 383-389
Published: 2015
Released on J-STAGE: December 03, 2015
JOURNAL FREE ACCESSHelicobacter pylori infects human stomach and cause various gastric diseases including gastric cancer. The species is also known for rapid evolution and wide geographical diversity of genome sequence. Our team sequenced whole genome sequences of H. pylori strains isolated from Japanese patients and compared with whole genome sequences of H. pylori strains with other geographic origin and found that not only the gene repertoire but also genome structures and epigenetic modifications such as DNA methylations had large diversity with various mechanisms. Genome inversion events were geography specific and some of them were found to occur with gene duplication at their termini. DNA methylation states of H. pylori genomes suggested that they are diversified by both existence/absence repertoire of methyltransferase genes and by the movement of target recognition domain in the methyltransferase genes. Omics analysis revealed that methylation target sequence and transcriptome status are actually diversified by the domain sequence movement. We suggested that H. pylori utilizes these genome structure and methylome diversity for its adaptive evolution.View full abstractDownload PDF (1554K) -
Miki KAWADA-MATSUO2015 Volume 70 Issue 4 Pages 391-397
Published: 2015
Released on J-STAGE: December 03, 2015
JOURNAL FREE ACCESSIt is known that various antibacterial agents are observed in human for preventing bacterial infection. In this study, in order to elucidate the resistance mechanism against antimicrobial agents derived of human and bacteriocins derived of commensal bacteria, we systematically evaluated the roles of the bacteria-specific two-component systems of Staphylococcus aureus and Streptococcus mutans which colonize to different sites. Two-component systems (TCSs) are specific regulatory systems in bacteria that play an important role in sensing and adapting to the environment.
As the result, four TCSs of S. aureus and three TCSs of S. mutans were associated with resistance against defensin and LL37 as antimaicrobial peptides and nisin A and nukacin ISK-1 as bacteriocins. Two TCSs that are individually associated with resistance against the bacteriocins nisin A (class I type A[I]) and nukacin ISK-1 (class I type A[II]) were identified in S. mutans, whereas one TCS is associated with main resistance against the both of nisin A and nukacin ISK-1. This result suggested that TCSs play important roles on acquisition of human- and bacteria-derived antibacterial agents. However, the resistance mechanism via TCS in S. aureus is quite different from that of in S. mutans.
Additional evidence suggests that these TCSs are required for co-existence with other bacteria producing to nisin A or nukacin ISK-1, meaning that the roles of bacteriocins in the interactions between different species of commensal bacteria and the importance of TCSs in this process.
Our results will highlight the roles of bacterial colonization in human being are constituted on the adaptation against antibacterial agents derived from human and commensal bacteria via TCSs.View full abstractDownload PDF (2978K)
- |<
- <
- 1
- >
- >|