• Journal of Microbiology and Biotechnology
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• 제31권1호
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• pp.130-136
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• 2021

Persister cell formation and biofilms of pathogens are extensively involved in the development of chronic infectious diseases. Eradicating persister cells is challenging, owing to their tolerance to conventional antibiotics, which cannot kill cells in a metabolically dormant state. A high frequency of persisters in biofilms makes inactivating biofilm cells more difficult, because the biofilm matrix inhibits antibiotic penetration. Fatty acids may be promising candidates as antipersister or antibiofilm agents, because some fatty acids exhibit antimicrobial effects. We previously reported that fatty acid ethyl esters effectively inhibit Escherichia coli persister formation by regulating an antitoxin. In this study, we screened a fatty acid library consisting of 65 different fatty acid molecules for altered persister formation. We found that undecanoic acid, lauric acid, and N-tridecanoic acid inhibited E. coli BW25113 persister cell formation by 25-, 58-, and 44-fold, respectively. Similarly, these fatty acids repressed persisters of enterohemorrhagic E. coli EDL933. These fatty acids were all medium-chain saturated forms. Furthermore, the fatty acids repressed Enterohemorrhagic E. coli (EHEC) biofilm formation (for example, by 8-fold for lauric acid) without having antimicrobial activity. This study demonstrates that medium-chain saturated fatty acids can serve as antipersister and antibiofilm agents that may be applied to treat bacterial infections.

• Animal Bioscience
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• 제35권4호
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• pp.587-595
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• 2022

Objective: The present study was conducted to evaluate the effects of dietary supplementation with Bifidobacterium animalis, Agave fructans, and symbiotic of both encapsulated on growth performance, feed efficiency, blood parameters, and immune status in broiler chickens, and to compare these with diets including antibiotic growth promoters and without additives. Methods: A comparative experimental study was carried out with 135 male Ross 308 broiler chickens. Each trial was divided into 5 equal groups. Control group (CON) received a standard diet without growth promoter; GPA, a standard diet with colistin sulfate and zinc bacitracin (0.25 g/kg of feed); PRE, a standard diet with 1% Agave fructans; PRO, a standard diet with Bifidobacterium animalis (11.14±0.70 log CFU/g); SYM, a standard diet with B. animalis and Agave fructans. Results: A significant decrease in food consumption was found for the GPA, PRE, and SYM, compared to the CON group. The results show a better feed conversion index in PRE and GPA with respect to the CON group with the highest conversion index. Interestingly, the weight of the gastrointestinal tract shows a statistically significant difference between GPA and PRE groups. Moreover, the length of the gastrointestinal tract of the GPA group was less than the PRE group. In the total leukocyte count, there was a statistically significant increase in the GPA group compared to the CON, PRE, and PRO groups, and the heterophiles-lymphocytes index was lower in PRO. Regarding the cytokines, interleukin 10 (IL-10) decreased in PRO compared to CON and PRE, while IL-1β increased in the SYM group. Conclusion: Alternative treatments were shown to achieve similar productive results as growth-promoting antibiotics and showed improvement over diet without additives; however, they have immunomodulatory properties and improved the development of the gastrointestinal tract compared to the treatment of growth-promoting antibiotics.

• Journal of Ginseng Research
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• 제47권2호
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• pp.265-273
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• 2023

Background: The intestinal microbiota is an important regulator of bone health. In previous studies we have shown that intestinal microbiota dysbiosis, induced by treatment with broad spectrum antibiotics (ABX) followed by natural repopulation, results in gut barrier dysfunction and bone loss. We have also shown that treatment with probiotics or a gut barrier enhancer can inhibit dysbiosis-induced bone loss. The overall goal of this project was to test the effect of Korean Red Ginseng (KRG) extract on bone and gut health using antibiotics (ABX) dysbiosis-induced bone loss model in mice. Methods: Adult male mice (Balb/C, 12-week old) were administered broad spectrum antibiotics (ampicillin and neomycin) for 2 weeks followed by 4 weeks of natural repopulation. During this 4-week period, mice were treated with vehicle (water) or KRG extract. Other controls included mice that did not receive either antibiotics or KRG extract and mice that received only KRG extract. At the end of the experiments, we assessed various parameters to assess bone, microbiota and in vivo intestinal permeability. Results: Consistent with our previous results, post-ABX- dysbiosis led to significant bone loss. Importantly, this was associated with a decrease in gut microbiota alpha diversity and an increase in intestinal permeability. All these effects including bone loss were prevented by KRG extract treatment. Furthermore, our studies identified multiple genera including Lactobacillus and rc4-4 as well as Alistipes finegoldii to be potentially linked to the effect of KRG extract on gut-bone axis. Conclusion: Together, our results demonstrate that KRG extract regulates the gut-bone axis and is effective at preventing dysbiosis-induced bone loss in mice.

• 대한한방내과학회지
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• 제44권3호
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• pp.455-465
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• 2023

Inflammatory bowel disease (IBD) is defined as a chronic inflammatory-mediated disease that causes ulceration and inflammation in the gastrointestinal tract. Among most patients, the course of chronic inflammation repeatedly shows intermittent exacerbations and alternating remissions. However, despite the various therapeutic options to relieve symptoms, such as corticosteroids, TNF-α inhibitors, and antibiotic drugs, there is no known cure for IBD. Nonetheless, previous research has revealed that the autonomic nervous system is involved in the pathophysiology of IBD. In this study, we reviewed clinical trials confirming the therapeutic effect of vagus nerve stimulation (VNS) on IBD in vivo. We searched in vivo and human studies on Pubmed using keywords combined with "vagus nerve stimulation", "VNS", and "inflammatory bowel disease". All studies included in this review reported that direct VNS is effective in relieving symptoms of IBD and has no severe adverse effects. The most frequently stimulated site was the unilateral cervical vagus nerve area, and parameters for stimulation were set as 5-20 Hz. Based on the results, we aim to summarize the evidence for the efficacy of VNS on IBD and suggest the possibility of auricular electroacupuncture treatment as a therapeutic option for IBD.

• 한국축산식품학회지
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• 제43권6호
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• pp.1111-1127
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• 2023

Health-promoting preparations of inanimate microorganisms or their components are postbiotics. Since probiotics are sensitive to heat and oxygen, postbiotics are stable during industrial processing and storage. Postbiotics boost poultry growth, feed efficiency, intestinal pathogen reduction, and health, making them acceptable drivers of sustainable poultry production. It contains many important biological properties, such as immunomodulatory, antioxidant, and anti-inflammatory responses. Postbiotics revealed promising antioxidant effects due to higher concentrations of uronic acid and due to some enzyme's production of antioxidants, e.g., superoxide dismutase, glutathione peroxidase, and nicotinamide adenine dinucleotide oxidases and peroxidases. Postbiotics improve intestinal villi, increase lactic acid production, and reduce Enterobacteriaceae and fecal pH, all of which lead to a better immune reaction and health of the gut, as well as better growth performance. P13K/AKT as a potential target pathway for postbiotics-improved intestinal barrier functions. Similarly, postbiotics reduce yolk and plasma cholesterol levels in layers and improve egg quality. It was revealed that favorable outcomes were obtained with various inclusion levels at 1 kg and 0.5 kg. According to several studies, postbiotic compounds significantly increased poultry performance. This review article presents the most recent research investigating the beneficial results of postbiotics in poultry.

• Journal of Veterinary Science
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• 제25권1호
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• pp.11.1-11.16
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• 2024

Background: Canine parvoviral enteritis (CPE) is a fatal disease worldwide. The treatment of CPE is based mainly on supportive and symptomatic treatment. Antiviral addition to the treatment may result in a higher survival. Objectives: This study evaluated the effects of antiviral treatments with a standardized treatment (ST) on the clinical and inflammatory response of dogs with naturally occurring CPE. Methods: Twenty-eight dogs with CPE caused by canine parvovirus type 2 were divided randomly into treatment groups. The ST group received fluid, antibiotic, antiemetic, and deworming treatments. The antiviral treatment groups received the same ST with an additional antiviral drug, recombinant feline interferon omega (rFeIFN-ω), oseltamivir (OSEL) or famciclovir (FAM). Results: Compared to the healthy control, the tumor necrosis factor-α, interleukin-1β, interferon (IFN)-α, IFN-γ, haptoglobin, and C-reactive protein values were high (p < 0.05) on day zero. At presentation, mild lymphopenia, neutropenia, and a high neutrophil to lymphocyte (LYM) ratio (NLR) were also observed. Adding rFeIFN-ω to the ST produced the best improvement in the clinical score with a decreased NLR, while leucocytes remained low and inflammatory markers stayed high on day three. The survival rates of the groups were 85.7% in ST+IFN, 71.4% in ST+OSEL, 71.4% in ST+FAM, and 57.1% in ST groups on day seven. Conclusions: Antiviral drugs may be valuable in treating CPE to improve the clinical signs and survival. In addition, the decrease in NLR in favor of LYM may be an indicator of the early prognosis before the improvement of leukocytes, cytokines, and acute phase proteins in CPE.

• IMMUNE NETWORK
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• 제20권3호
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• pp.25.1-25.13
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• 2020

Acinetobacter baumannii is known for its multidrug antibiotic resistance. New approaches to treating drug-resistant bacterial infections are urgently required. Cathelicidin-related antimicrobial peptide (CRAMP) is a murine antimicrobial peptide that exerts diverse immune functions, including both direct bacterial cell killing and immunomodulatory effects. In this study, we sought to identify the role of CRAMP in the host immune response to multidrug-resistant Acinetobacter baumannii. Wild-type (WT) and CRAMP knockout mice were infected intranasally with the bacteria. CRAMP^-/- mice exhibited increased bacterial colony-forming units (CFUs) in bronchoalveolar lavage (BAL) fluid after A. baumannii infection compared to WT mice. The loss of CRAMP expression resulted in a significant decrease in the recruitment of immune cells, primarily neutrophils. The levels of IL-6 and CXCL1 were lower, whereas the levels of IL-10 were significantly higher in the BAL fluid of CRAMP^-/- mice compared to WT mice 1 day after infection. In an in vitro assay using thioglycollate-induced peritoneal neutrophils, the ability of bacterial phagocytosis and killing was impaired in CRAMP^-/- neutrophils compared to the WT cells. CRAMP was also essential for the production of cytokines and chemokines in response to A. baumannii in neutrophils. In addition, the A. baumannii-induced inhibitor of κB-α degradation and phosphorylation of p38 MAPK were impaired in CRAMP^-/- neutrophils, whereas ERK and JNK phosphorylation was upregulated. Our results indicate that CRAMP plays an important role in the host defense against pulmonary infection with A. baumannii by promoting the antibacterial activity of neutrophils and regulating the innate immune responses.

• Investigative and Clinical Urology
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• 제63권3호
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• pp.334-340
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• 2022

Purpose The prevalence of catheter-associated urinary tract infections (CAUTIs) varies from 5% to 8.2%, and the risk of infection increases by 5% to 7% per day of primary indwelling. We investigated whether a novel biofilm inhibitory mechanism using an inhibitory silicone urethral catheter (a coated Foley catheter) can reduce CAUTIs compared to conventional non-coated Foley catheters. Materials and Methods This study prospectively analyzed the difference in the incidence of CAUTIs in patients who underwent radical cystectomy with an orthotopic neobladder for bladder cancer and received a coated or conventional non-coated catheter. Additionally, differences in bacterial colonization between the groups were analyzed using a catheter-tip bacterial culture test. Results Eighty-five patients were randomized into the "coated Foley catheter" group (abbreviated as "case" group; 41 patients) and a control group (44 patients). The two groups were identical except for their surgical history. The incidence of CAUTIs 2 weeks after radical cystectomy was 21.95% (case) and 27.27% (control), with no significant difference between the two groups. However, when the catheter was removed 2 weeks after surgery, the catheter tip culture test revealed significant bacterial colonies in 25 (60.98%) and 38 (86.36%) patients in the case and control group, respectively. No catheter-related postoperative side effects were observed in either group. Conclusions The incidence of CAUTIs in the two groups did not differ according to the catheter material. However, the catheter bacterial culture test showed that bacterial colonization was significantly suppressed on the Bi-Fi Free technology catheter, which comparatively inhibited biofilm formation.

• Journal of Animal Science and Technology
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• 제48권3호
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• pp.375-382
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• 2006

본 시험에 사용된 생약제제는 지황, 천궁, 감초, 오미자, 차전차, 산약, 둥글레, 당귀 및 황백 등 24가지의 생약을 적절히 배합한 혼합생약제제(고뿔??)로서 육성돈 사료에 첨가 급여시 생산성, 혈액 내 면역관련 혈액학적 지표, 분내 휘발성 지방산 및 암모니아태 질소 함량에 미치는 영향을 규명하고자 실시하였다. 시험동물은 3원 교잡종(Landrace×Yorkshire×Duroc) 육성돈 80두를 공시하였으며 시험개시시의 체중은 16.35±0.05kg 이었고 1) NC (negative control; antibiotics-free diet), 2) PC (positive control; NC diet added 0.16% antibiotic), 3) NCK0.2 (NC diet added 0.2% herbal product(koppuul??)), 4) PCK0.1 (PC diet added 0.1% herbal product (koppuul??))로 4개 처리를 하여 처리당 5반복 반복당 4두씩 임의 배치하여 42일간 실시하였다. 총 사양시험 기간 동안 일당증체량에서는 PCK0.1구와 PC구가 NC구와 비교하여 유의적으로 높게 나타났고(P<0.05) 사료효율에서는 PC구가 NC구와 비교하여 유의적으로 높았다(P<0.05). 혈액 내 백혈구수와 IgG 함량의 변화는 PC, NCK0.2와 PCK0.1구가 NC구와 비교하여 유의적으로 높은 경향을 보였다(P<0.05). Lymphocyte의 경우 PCK0.1구에서 증가량이 유의적으로 가장 높았으며 대조구가 가장 낮게 나타났다(P<0.05). 분내 암모니아태 질소 함량을 보면 NCK0.2구가 항생제를 첨가한 PC구와 대조구에 비해 유의하게 낮은 결과를 보였다(P<0.05). 건물과 질소 소화율에서는 항생제를 0.16% 첨가한 PC구에서 높은 경향을 보였으나 전 처리구에서 유의적인 차이를 보이지 않았다. 결과적으로 육성돈 사료 내 생약제 또는 항생제 첨가시 일당증체량, 혈액 내 백혈구수와 IgG 함량을 증가시키고 분내 암모니아태 질소 함량을 감소시키는 것으로 사료된다.

• 한국가금학회지
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• 제35권2호
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• pp.123-129
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• 2008

본 연구의 목적은 고에너지 사료 내 항생제와 효모제의 첨가가 육계의 생산성, 혈액 성상 및 도체 특성에 미치는 영향을 알아보기 위하여 실시하였다. 2일령 Arbor Acre broiler (male, female) 480수를 공시하였고, 사양 시험은 5주간 실시하였다. 시험사료는 옥수수-대두박 위주의 사료인 대조구(CON; basal diet), 고에너지 사료 처리구(HED; high energy diet), 효모제 사료 처리구(YD; HED without virginiamycin + 0.2% Saccharomyces cerevisiae, $15{\times}10^{10}$)로 3개 처리를 하여 처리당 8반복, 반복당 20수씩 완전 임의 배치하였다. 전체 사양 시험 기간동안 증체량은 고에너지 사료를 급여한 HED 처리구가 다른 처리구들에 비해 높은 경향을 보였으나, 처리구간에 유의적인 차이는 없었다. 사료 섭취량은 효모제 사료를 급여한 YD 처리구가 다른 처리구들에 비해 높은 경향을 보였으나, 처리구간에 유의적인 차이는 없었다. 사료 요구율에서는 고 에너지 사료를 급여한 HED 처리구가 다른 처리구들에 비해 유의적으로 낮게 나타났다(P<0.05). RBC(red blood cell), WBC (white blood cell), lymphocyte 모두 처리구간에 유의적인 차이는 없었으며, 간 무게 및 생체중에 대한 간 무게 비율, 허벅지육 무게 및 생체중에 대한 허벅지육 비율, 가슴육 무게 및 생체중에 대한 가슴육 무게 비율, 복강 지방 무게 및 생체중에 대한 복강 지방 무게 비율 모두에서 유의적인 차이가 없었으나, 종료시 체중에서는 HED 처리구가 유의적으로 가장 높았으며, 다음으로 YD, CON 순이었다(P<0.05). 결론적으로, 고에너지 사료 처리구가 사료 요구율에서 유의적으로 가장 영향을 미쳤으며, 효모제 처리구는 CON 처리구와 많은 차이를 보이지 않았다.