Biofilm formation and eradication in Mycoplasma hyopneumoniae

Abraham Mechesso,Biruk Birhanu,Seung Chun Park 대한수의학회 2016 대한수의학회 학술대회발표집 Vol.2016 No.-

Ginsenoside Rg3 reduces the adhesion, invasion, and intracellular survival of Salmonella enterica serovar Typhimurium

Abraham F. Mechesso,Yixian Quah,Seung-Chun Park 고려인삼학회 2021 Journal of Ginseng Research Vol.45 No.1

Background: Invasive infections due to foodborne pathogens, including Salmonella enterica serovar Typhimurium, are prevalent and life-threatening. This study aimed to evaluate the effects of ginsenoside Rg3 (Rg3) on the adhesion, invasion, and intracellular survival of S. Typhimurium. Methods: The impacts of Rg3 on bacterial growth and host cell viability were determined using the time kill and the 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2H-tetrazolium bromide assays, respectively. Gentamicin assay and confocal microscopic examination were undertaken to determine the effects of Rg3 on the adhesive and invasive abilities of S. Typhimurium to Caco-2 and RAW264.7 cells. Quantitative reverse transcription polymerase chain reaction was performed to assess the expression of genes correlated with the adhesion, invasion, and virulence of S. Typhimurium. Results: Subinhibitory concentrations of Rg3 significantly reduced (p < 0.05) the adhesion, invasion, and intracellular survival of S. Typhimurium. Rg3 considerably reduced (p < 0.05) the bacterial motility as well as the release of nitrite from infected macrophages in a concentration-dependent manner. The expression of genes related to the adhesion, invasion, quorum sensing, and virulence of S. Typhimurium including cheY, hilA, OmpD, PrgK, rsgE, SdiA, and SipB was significantly reduced after Rg3 treatment. Besides, the compound downregulated rac-1 and Cdc-42 that are essential for actin remodeling and membrane ruffling, thereby facilitating Salmonella entry into host cells. This report is the first to describe the effects of Rg3 on “trigger” entry mechanism and intracellular survival S. Typhimurium. Conclusion: Rg3 could be considered as a supplement agent to prevent S. Typhimurium infection.

Biofilm formation and determination of minimum biofilm eradication concentration of antibiotics in <i>Mycoplasma hyopneumoniae</i>

TASSEW, Dereje Damte,MECHESSO, Abraham Fikru,PARK, Na-Hye,SONG, Ju-Beom,SHUR, Joo-Woon,PARK, Seung-Chun The Japanese Society of Veterinary Science 2017 The Journal of veterinary medical science Vol.79 No.10

<P>The study was aimed to investigate biofilm forming ability of <I>Mycoplasma hyopneumoniae</I> and to determine the minimum biofilm eradication concentrations of antibiotics. Biofilm forming ability of six strains of <I>M. hyopneumoniae</I> was examined using crystal violet staining on coverslips. The results demonstrated an apparent line of biofilm growth in 3 of the strains isolated from swine with confirmed cases of enzootic pneumonia. BacLight bacterial viability assay revealed that the majority of the cells were viable after 336 hr of incubation. Moreover, <I>M. hyopneumoniae</I> persists in the biofilm after being exposed to 10 fold higher concentration of antibiotics than the minimum inhibitory concentrations in planktonic cells. To the best of our knowledge, this is the first report of biofilm formation in <I>M. hyopneumoniae.</I> However, comprehensive studies on the mechanisms of biofilm formation are needed to combat swine enzootic pneumonia caused by resistant <I>M. hyopneumoniae</I>.</P>

The phenotypic and molecular resistance induced by a single-exposure to sub-mutant prevention concentration of marbofloxacin in <i>Salmonella</i> Typhimurium isolates from swine

Lee, Seung-Jin,Park, Na-Hye,Mechesso, Abraham Fikru,Lee, Kwang-Jick,Park, Seung-Chun Elsevier Scientific Pub. Co 2017 Veterinary microbiology Vol.207 No.-

<P><B>Abstract</B></P> <P>In the present study, the molecular mechanisms of antibiotic resistance in <I>Salmonella</I> Typhimurium clinical isolates from pigs were investigated using a single-step mutation model of exposure to sub-mutant prevention concentrations (MPCs) of marbofloxacin. The minimum inhibitory concentrations (MICs) of seven antibacterial drugs were evaluated against 30 <I>S.</I> Typhimurium clinical isolates from different pigs. MPCs of marbofloxacin were also determined. The mechanism of marbofloxacin-resistance was investigated by sequencing analysis of target gene mutations and quantifying the overexpression of efflux pumps and their regulators by quantitative RT-PCR. Marbofloxacin showed the highest potency against all isolates (23.3%), including multi-drug resistant isolates. The MPC<SUB>50</SUB> (0.5μg/mL) and MPC<SUB>90</SUB> (2μg/mL) of marbofloxacin were determined, as were MPC/MIC ratios of 2.5 to 8. A <I>gyrA</I> mutation (Ser83Phe or Asp87His) was detected in isolates with an MIC>0.06μg/mL and all single-step mutants. Moreover, expression of <I>acrAB-tolC</I> and <I>marA</I>/<I>soxS</I>/<I>ramA</I> increased following a single-step mutation, but only <I>ramA</I> expression showed a positive correlation with the resistance phenotype of clinical isolates and single-step mutants (<I>p<</I> 0.05). Furthermore, the <I>acrR</I> mutation was detected in two clinical isolates and 50% of single-step mutants, regardless of whether the <I>gyrA</I> mutation was present. This is the first report of <I>acrR</I> mutations in <I>S</I>. Typhimurium isolates from pigs in Korea. Our findings suggest that a single-exposure to sub-MPCs of marbofloxacin was sufficient to reduce the susceptibility of <I>Salmonella</I> isolates. Therefore, optimized dosing based on application with the MPC concept is required to reduce the chances of marbofloxacin resistance.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Multi-drug resistance was found in 36.7% of <I>Salmonella</I> Typhimurium clinical isolates from swine; only 36.4% among them were susceptible to marbofloxacin. </LI> <LI> The resistance phenotypes in isolates increased after a single-exposure to sub-MPCs of marbofloxacin. </LI> <LI> Target mutation (<I>gyrA</I>)-based and/or efflux pump (<I>acrAB</I>-<I>tolC</I>)-mediated marbofloxacin resistance in clinical isolates and single-step mutants were identified. </LI> <LI> Expression of <I>acrAB</I>-<I>tolC</I> was associated with global regulators (<I>marA</I>/<I>soxS</I>/<I>ramA</I>) and/or a local regulator (<I>acrR</I>). </LI> <LI> This is the first report on the identification of <I>S.</I> Typhimurium isolates with <I>acrR</I> mutations in Korea. </LI> </UL> </P>

Enhancement of Lipid Metabolism and Hepatic Stability in Fat-Induced Obese Mice by Fermented <i> Cucurbita moschata</i> Extract

Hossain, Md. Akil,Lee, Seung-Jin,Park, Na-Hye,Birhanu, Biruk Tesfaye,Mechesso, Abraham Fikru,Park, Ji-Yong,Park, Eun-Jin,Lee, Sam-Pin,Youn, Sun-Joo,Park, Seung-Chun Hindawi 2018 Evidence-based Complementary and Alternative Medic Vol.2018 No.-

<P>The aim of this study was to evaluate the potentials of fermented<I> Cucurbita moschata</I> extract (FCME) in the treatment of obesity and nonalcoholic fatty liver disease (NAFLD). Five-week-old male C57BL/6 mice were assigned to 6 groups and treated for 8 weeks by feeding the normal diet (ND) and high fat diet (HFD) with and without FCME. Changes in body weight gain and consumption of feed and water were recorded. Major organs, adipose tissues, and blood samples were collected after the experimental period. The serum lipid profile, histological features of liver and adipose tissues, and mRNA expression of different adipogenic/lipogenic genes from liver tissue were evaluated. The supplementation of FCME in HFD significantly prevented HFD-induced increment of bodyweight. The adipose tissue mass, liver enzymes, and plasma lipids were also reduced significantly (<I>p</I> < 0.05) by the consumption of FCME. The mRNA expressions of adipogenic/lipogenic genes (PPAR<I>γ</I>, C/EBP<I>α</I>, C/EBP<SUB><I>β</I></SUB>, C/EBP<I>γ</I>, and SREBP-1C) in FCME-treated obese mice were considerably (<I>p</I> < 0.05) suppressed. FCME showed its antiobesity potential by suppressing the body weight gain and by modulating the plasma lipids and liver enzymes through the regulation of adipogenic/lipogenic transcriptional factors. Fermented<I> Cucurbita moschata</I> could be an opportunistic agent in controlling obesity and fatty liver changes.</P>