Bacterial Cell-Free Probiotics Using Effective Substances Produced by Probiotic Bacteria, for Application in the Oral Cavity

To avoid side effects of conventional antibiotics and disinfectants used for prevention of oral diseases such as dental caries, periodontitis, and oral candidiasis, application of probiotics has attracted attention recently. However, difficulties arise when applying those probiotics in the oral cavity, because exogenous probiotic bacteria do not colonize easily in the established oral microbiota. Even, if we are able to overcome the restriction of colonization by probiotic bacteria in the oral cavity, it comes with the risk of dental caries due to the potential acidic environment generated by probiotic bacteria. To solve these problems, “biogenics,” bacterial cell-free probiotics using only the effective substances metabolically produced by probiotic bacteria, is recommended for application in the oral cavity. The concept and frontline of biogenic research will be introduced and discussed

Host cell invasion and oral infection by Trypanosoma cruzi strains of genetic groups TcI and TcIV from chagasic patients

Background: Outbreaks of acute Chagas disease by oral infection have been reported frequently over the last ten years, with higher incidence in northern South America, where Trypanosoma cruzi lineage TcI predominates, being responsible for the major cause of resurgent human disease, and a small percentage is identified as TcIV. Mechanisms of oral infection and host-cell invasion by these parasites are poorly understood. To address that question, we analyzed T. cruzi strains isolated from chagasic patients in Venezuela, Guatemala and Brazil. Methods: Trypanosoma cruzi metacyclic trypomastigotes were orally inoculated into mice. The mouse stomach collected four days later, as well as the stomach and the heart collected 30 days post-infection, were processed for histological analysis. Assays to mimic parasite migration through the gastric mucus layer were performed by counting the parasites that traversed gastric mucin-coated transwell filters. For cell invasion assays, human epithelial HeLa cells were incubated with metacyclic forms and the number of internalized parasites was counted. Results: All TcI and TcIV T. cruzi strains were poorly infective by the oral route. Parasites were either undetectable or were detected in small numbers in the mouse stomach four days post oral administration. Replicating parasites were found in the stomach and/or in the heart 30 days post-infection. As compared to TcI lineage, the migration capacity of TcIV parasites through the gastric mucin-coated filter was higher but lower than that exhibited by TcVI metacyclic forms previously shown to be highly infective by the oral route. Expression of pepsin-resistant gp90, the surface molecule that downregulates cell invasion, was higher in TcI than in TcIV parasites and, accordingly, the invasion capacity of TcIV metacyclic forms was higher. Gp90 molecules spontaneously released by TcI metacyclic forms inhibited the parasite entry into host cells. TcI parasites exhibited low intracellular replication rate. Conclusions: Our findings indicate that the poor capacity of TcI lineage, and to a lesser degree of TcIV parasites, in invading gastric epithelium after oral infection of mice may be associated with the inefficiency of metacyclic forms, in particular of TcI parasites, to migrate through the gastric mucus layer, to invade target epithelial cells and to replicate intracellularly.Fundacao de Amparo a Pesquisa do Estado de Sao Paulo (FAPESP)Conselho Nacional de Desenvolvimento Cientifico e Tecnologico (CNPq)Univ Fed Sao Paulo, Dept Microbiol Imunol & Parasitol, Sao Paulo, BrazilUniv Fed Sao Paulo, Dept Microbiol Imunol & Parasitol, Sao Paulo, BrazilFAPESP: 11/51475-3CNPq: 300578/2010-5Web of Scienc

Rapid screening method for detecting highly pathogenic Streptococcus intermedius strains carrying a mutation in the lacR gene

Streptococcus intermedius is a member of the normal human commensal flora and secretes a human-specific cytolysin intermedilysin (ILY) as a major virulence factor. Expression of ily is repressed by LacR and loss-of-function mutations of LacR are observed in many ILY high-producing strains isolated from deep-seated abscesses, suggesting that high ILY production is necessary for increased virulence. However, because ILY exhibits no β-hemolysis on animal blood agar plates, differentiating ILY high- and low-producing strains using conventional laboratory methods is not possible. Interestingly, S. intermedius also produces glycosidases, including MsgA and NanA, which exhibit N-acetyl-β-D-glucosaminidase and neuraminidase activities, respectively. Moreover, MsgA expression, but not NanA, is negatively regulated by LacR. Here we measured the activities of MsgA, NanA and ILY in strains isolated from clinical specimens and dental plaque to determine the correlation between these glycosidase activities and ILY hemolytic activity. Hemolytic activity showed a strong positive correlation with MsgA and a weak negative correlation with NanA activities. Therefore, we calculated the ratio of MsgA and NanA activity (M/N ratio). This value showed a stronger positive correlation (r = 0.81) with ILY hemolytic activity and many strains with high M/N ratios (> 2) were ILY high-producers with loss-of-function mutations in LacR.Rapid screening method for highly pathogenic S. intermedius strains based on the ratio of activities of MsgA and NanA resulting from lacR mutations

Nursing students' perception of their acquired basic skills in nursing practices : a comparison between a new and an old curriculum

平成2年度改正の新カリキュラムで学んだ学生と旧カリキュラムで学んで学生間に、卒業時の基礎看護技術の到達度に違いがあるかを明らかにするために、看護技術の基本的要素、日常生活の援助技術、診療時の援助技術の49項目の到達度について、3年制課程の3年生に質問紙調査を行った。対象者全体では、到達度の上位10位以内に日常生活の援助技術項目の37％が含まれ、到達度の下位10位以内に診療時の援助技術項目の37％が含まれていた。新カリキュラム群と旧カリキュラム群の比較では、21項目に有意差があった。新カリキュラム群の高い15項目は日常生活の援助技術と看護技術の基本的要素に関するものが多く、旧カリキュラム群が高い6項目は診療時の援助技術が多かった。カリキュラム改正に関係なく、日常生活の援助技術の到達度は高く診療時の援助技術は低い傾向にあったが、カリキュラム改正後はその傾向が強まり、さらに看護技術の基本的要素の到達度はカリキュラム改正後に比較的高くなっていることが明らかになった。新カリキュラムでは臨地実習時間を削減しているが、基礎教育で重視する日常生活の援助技術と看護技術の基本的要素は習得できていると考えられる。A revision was made in a nursing curriculum in 1990. This study examined nursing students' perceived level of acquired 49 basic skills in nursing practices consisting of 11 basal elements of nursing skill, 19 skills in helping patients' daily activities, and 19 skills required in medical situations, comparing students receiving a new curriculum with those receiving an old one. Findings showed that in the rank ordering of all items from the best acquired to the least, collapsed across the two groups of students, 37% of the upper 10 items cocerned the skills in helping patients' daily activities, while 37% of the bottom 10 items concerned the skills required in medical situation. The students receiving the new curriculum perceived themselves better than those reseiving the old one for 15 items that were related with the basal elements of nursing skill and the skills in helping patients' daily activities, while the 6 items in the skills required in medical situations were perceived to be better acquired for the latter than the former students. The finding suggest that the new curriculum produced students who perceive themselves to be better achievers in the basic skills in nursing practices

Risk assessment for hepatitis E virus infection from domestic pigs introduced into an experimental animal facility in a medical school

Hepatitis E virus (HEV) is known to cause zoonotic infections from pigs, wild boars and deer. Domestic pigs have been used as an experimental animal model in medical research and training; however, the risks of HEV infection from pigs during animal experiments are largely unknown. Here, we retrospectively investigated the seroprevalence and detection rates of viral RNA in 73 domestic pigs (average 34.5 kg) introduced into an animal experimental facility in a medical school during 2012-2016. We detected anti-HEV immunoglobulin G antibodies in 24 of 73 plasma samples (32.9%), though none of the samples were positive for viral RNA. Plasma samples of 18 pigs were sequentially monitored and were classified into four patterns: sustained positive (5 pigs), sustained negative (5 pigs), conversion to positive (6 pigs) and conversion to negative (2 pigs). HEV genomes were detected in 2 of 4 liver samples from pigs that were transported from the same farm during 2016-2017. Two viral sequences of the overlapping open reading frame (ORF) 2/3 region (97 bp) were identical and phylogenetically fell into genotype 3. A 459-bp length of the ORF2 region of an amplified fragment from a pig transported in 2017 was clustered with the wbJYG1 isolate (subgenotype 3b) with 91.5% (420/459 bp) nucleotide identity. Based on our results, we suggest that domestic pigs introduced into animal facilities carry a potential risk of HEV infection to researchers, trainees and facility staff. Continuous surveillance and precautions are important to prevent HEV infection in animal facilities

Co-infection with Trypanosoma cruzi protects mice against early death by neurological or pulmonary disorders induced by Plasmodium berghei ANKA

Objective: the objective of this study was to investigate whether the infection of C57BL/ 6 mice by P. berghei ANKA, which causes severe malaria, was modulated by co-infection with Trypanosoma cruzi.Methods: Groups of C57BL/ 6 mice were infected either with P. berghei ANKA, T. cruzi strain G, or with both parasites. the presence of parasites was checked by microscopic examination of blood samples. Symptoms of neurological or respiratory disorders, as well as mortality, were registered. Breakdown of the blood brain barrier was determined by injecting the dye Evans blue. Histological sections of the lung were prepared and stained with hematoxilin-eosin.Results: All mice infected only with P. berghei ANKA died within 7-11 days post-infection, either with symptoms of cerebral malaria or with respiratory abnormalities. the animals co- infected with T. cruzi strain G survived longer, without any of the referred to symptoms. Protection against the early death by severe malaria was effective when mice were given T. cruzi 15 days before P. berghei inoculation. Breakdown of the blood brain barrier and extensive pulmonary oedema, caused by malaria parasites, were much less pronounced in co- infected mice. the degree of protection to severe malaria and early death, conferred by co- infection with T. cruzi, was comparable to that conferred by treatment with anti-CD8 antibodies.Conclusion: Co-infection with T. cruzi protects C57BL/ 6 against the early death by malaria infection, by partially preventing either the breakdown of the blood brain, and cerebral malaria as a consequence, or the pulmonary oedema.Universidade Federal de São Paulo, Dept Microbiol Immunol & Parasitol, São Paulo, BrazilUniversidade Federal de São Paulo, Dept Morfol, São Paulo, BrazilUniv Estadual Campinas, Inst Biol, Dept Parasitol, Campinas, SP, BrazilUniversidade Federal de São Paulo, Dept Microbiol Immunol & Parasitol, São Paulo, BrazilUniversidade Federal de São Paulo, Dept Morfol, São Paulo, BrazilWeb of Scienc

An Experiment of the discovery study system in basic nursing technique in intramural practice -Help of eating and excreting-

The content of nursing education and the effective ways of studying nursing have been investigated by teachers of nursing. Therefore, in the lesson of "Basic Nursing Technique" did we examine the educational way in which the students' will to study nursing can be heightened and the students are able to work independently and creatively. we focused on the educational way which adopted the discovery study system in the lessons of "Help of Eating" and "Help of Excreting". From the viewpoint of the students' intention to study and their work, the effect of this educational way was researched according to their self-appreciation. As a result, the following four points were made clear by the introduction of the discovery study system. (1) The students could cooperate more easily in studying nursing. (2) The students' interest in nursing was heightened more than before. (3) The students could enhance their will to study nursing and work independently. (4) The items of "Sense of Purpose" and "Ingenuity" were less evaluaoed than the other items

Antibacterial and Antifungal Effect of 405 nm Monochromatic Laser on Endodontopathogenic Microorganisms

The purpose of this study is to evaluate the usefulness of 405 nm monochromatic laser irradiation as an alternative management for prevention and/or treatment of endodontic infections. A monochromatic laser-emitting device equipped with a 405-nm laser diode was developed. Using this device, the effect of 405 nm laser irradiation on the growth of Porphyromonas gingivalis, Prevotella intermedia, Enterococcus faecalis, and Candida albicans, which are microorganisms associated with persistent endodontic infections, was evaluated by viable colony counting. As a result, the irradiation with a 405 nm laser had a significant bactericidal/fungicidal effect on P. gingivalis, P. intermedia, and C. albicans, whereas the growth of E. faecalis was not affected by the irradiation. The inhibition rate in P. gingivalis and P. intermedia was ~60% and ~80%, respectively, following irradiation at 0.2 W for 300 sec. The inhibition rate in C. albicans was ~90% following irradiation at 0.2 W for 1200 sec. These results indicate that 405 nm monochromatic laser irradiation exerts a bactericidal/fungicidal effect on these microorganisms. The present study clearly demonstrates that 405 nm laser irradiation is a promising alternative management strategy for prevention and/or treatment of endodontic infections