Polymerase-chain reaction testing to prevent hospital-acquired severe acute respiratory syndrome coronavirus 2 infection in Shinjuku, an epicenter in Tokyo: The Tokyo Women's Medical University model.

Hospital-acquired severe acute respiratory virus coronavirus 2 (SARS-CoV-2) infection is a healthcare challenge. We hypothesized that polymerase chain reaction testing of symptomatic triaged outpatients and all inpatients before hospitalization in Shinjuku, a coronavirus disease 2019 (COVID-19) epicenter in Tokyo, using the Tokyo Women's Medical University (TMWU) model would be feasible and efficient at preventing COVID-19. This retrospective study enrolled 2981 patients from March to May 2020. The prevalence of SARS-CoV-2 infection was 1.81% (95% credible interval [CI]: 0.95-3.47%) in triaged symptomatic outpatients, 0.04% (95% CI: 0.0002-0.2%) in scheduled asymptomatic inpatients, 3.78% (95% CI: 1.82-7.26%) in emergency inpatients, and 2.4% (95% CI: 1.49-3.82%) in symptomatic patients. There were no cases of hospital-acquired SARS-CoV-2 infection. This shows that the TWMU model could prevent hospital-acquired SARS-CoV-2 infection and is feasible and effective in reducing the impact of SARS-CoV-2 infection in the hospitals.

Well-controlled proinflammatory cytokine responses of Peyer's patch cells to probiotic Lactobacillus casei.

SUMMARY: In order to clarify the probiotic features of immunomodulation, cytokine production by murine spleen and Peyer's patch (PP) cells was examined in response to probiotic and pathogenic bacteria. In spleen cells, probiotic Lactobacillus casei induced interleukin (IL)-12 production by CD11b(+) cells more strongly than pathogenic Gram-positive and Gram-negative bacteria and effectively promoted the development of T helper (Th) type 1 cells followed by high levels of secretion of interferon (IFN)-gamma. Although the levels of IL-12 secreted by PP cells in response to L. casei were lower in comparison with spleen cells, Th1 cells developed as a result of this low-level induction of IL-12. However, IFN-gamma secretion by the L. casei-induced Th1 cells stimulated with a specific antigen was down-regulated in PP cells. Development of IL-17-producing Th17 cells was efficiently induced in PP cells by antigen stimulation. Lactobacillus casei slightly, but significantly, inhibited the antigen-induced secretion of IL-17 without a decrease in the proportion of Th17 cells. No bacteria tested induced the development of IL-10-producing, transforming growth factor-beta-producing or Foxp3-expressing regulatory T cells, thus suggesting that certain probiotics might regulate proinflammatory responses through as yet unidentified mechanisms in PP cells. These data show probiotic L. casei to have considerable potential to induce IL-12 production and promote Th1 cell development, but the secretion of proinflammatory cytokines such as IL-12 and IL-17 may be well controlled in PP cells.

Peroxisome proliferator-activated receptor γ 2 mutation may cause a subset of ulcerative colitis.

AIM: Previous studies suggest the homeostasis between acquisition of tolerance to the indigenous microflora and protective immune responses appears to be disrupted in inflammatory bowel disease (IBD). Some experimental studies indicate peroxisome proliferator-activated receptor γ (PPARγ) has been implicated as a regulator of intestinal inflammatory responses. In addition, the toll-like receptor (TLR)-4 can regulate expression of PPARγ in colonic epithelial cells. We attempted to demonstrate whether the functional imbalance between TLRs and PPARγ could lead to the onset and some polymorphisms of those genes could contribute to susceptibility to IBD. METHODS: RT-PCR analysis were performed to detect TLR4 and PPARγ mRNA associated with those of P65 of NFκB, TNFα, MyD88, NOD2/CARD15, TLR-2,5,9, in the diseased colonic mucosa in ulcerative colitis (UC; n = 13) and Crohn's disease (CD; n = 7) compared with normal controls (n = 18). Consequently, we genotyped UC (n = 29) and CD (n = 10) compared with normal controls (n = 134) for the prevalence of suspicious mutations. RESULTS: In a subset of UC patients who were revealed to carry PPARγ Pro12Ala mutation later, impaired expression of normal PPARγ mRNA was noted in the diseased mucosa accompanied with upregulations of MyD88 TLR-4, 5, 9, P65 and TNFα in mRNA levels. The prevalence of PPARγ Pro12Ala mutation was more frequently found in UC patients compared with CD patients and normal controls (P < 0.05). CONCLUSIONS: These findings suggested that imbalances between TLRs and PPARγ in response to luminal bacteria could lead to colonic inflammation in some UC patients. Alternative explanations will be needed for the onset of the rest of UC and CD.

Anti-infectious activity of synbiotics in a novel mouse model of methicillin-resistant Staphylococcus aureus infection.

The anti-infectious activity of synbiotics against methicillin-resistant Staphylococcus aureus (MRSA) infection was evaluated using a novel lethal mouse model. Groups of 12 mice treated with multiple antibiotics were infected orally with a clinical isolate of MRSA at an inoculum of 10(8) CFU on day 7 after starting the antibiotics. A dose of 400 mg/kg 5-fluorouracil (5-FU) was injected intraperitoneally on day 7 after the infection. A dose of 10(8) CFU Bifidobacterium breve strain Yakult and 10 mg of galactooligosaccharides (GOS) were given orally to mice daily with the antibiotic treatment until day 28. The intestinal population levels of MRSA in the mice on multiple antibiotics were maintained stably at 10(8) CFU/g of intestinal contents after oral MRSA infection and the subsequent 5-FU treatment killed all the mice in the group within 14 days. B. breve administration saved most of the mice, but the synbiotic treatment saved all of the mice from lethal MRSA infection. The synbiotic treatment was effective for the treatment of intestinal infection caused by four MRSA strains with different toxin productions. There was a large difference among the six Bifidobacteria strains that were naturally resistant to the antibacterial drugs used. B. breve in combination with GOS is demonstrated to have valuable preventive and curative effects against even fatal MRSA infections.