Lactobacillus casei-fermented milk as an inhibitor on selected foodborne pathogens

The aim of this study was to reduce the growth of vanB resistant Enterococcus faecium, vanA resistant Enterococcus faecalis, Staphylococcus aureus ATCC 43300 and methicillin-resistant Staphylococcus aureus- MRSA ATCC 25923, which are foodborne pathogens that cause the death of a significant number of people every year, by the presence of Lactobacillus casei. For this purpose, the development of pathogens (104 and 106 log cfu/ml) in milk fermented with L. casei (106 log cfu/ml) was followed under in vitro conditions for 72 hours. Moreover, the generation times of each pathogen and the lactic acid content of fermented milk were determined. It was determined that the development of all pathogens could be suppressed by the presence of L. casei considering the change in generation times and the number of pathogens during the 72 hour fermentation period. This effect was greater in samples containing 104 log cfu/ml pathogen compared to samples containing 106 log cfu/ml.

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UJI KEMAMPUAN Lactobacillus casei SEBAGAI AGENSIA PROBIOTIK

Jurnal Bioteknologi & Biosains Indonesia (JBBI) ◽

10.29122/jbbi.v1i1.546 ◽

2014 ◽

Vol 1 (1) ◽

pp. 9 ◽

Cited By ~ 1

Author(s):

Rofiq Sunaryanto ◽

Efrida Martius ◽

Bambang Marwoto

Keyword(s):

Escherichia Coli ◽

Staphylococcus Aureus ◽

Antimicrobial Activity ◽

Lactic Acid ◽

Lactic Acid Bacteria ◽

Enterococcus Faecalis ◽

Lactobacillus Casei ◽

Acid Media ◽

Genus Lactobacillus

Growth Ability of Jatropha Curcas L. Explants on the In Vitro Media Containing IBA and BAProbiotic product is one of the applications of biotechnology that utilize lactic acid bacteria, especially lactobacilli. Some important requirements for microbes that can be used as probiotic include resistance to low pH, ability to grow on bile salts and colonize, and having antimicrobial activity. Each species of the genus Lactobacillus has different characteristics. These characteristics are strongly influenced by the environment in which the bacteria live. This study was carried out in order to characterize Lactobacillus casei which was isolated from dadih. The result of the experiment showed that the isolated L. casei was able to grow on the bile salt at the concentration of 15%, resistant to acid media until pH 2, had antimicrobial activity (significantly inhibited the growth of Escherichia coli, Staphylococcus aureus, and Enterococcus faecalis). The local L. casei isolate has a potential application for use as probiotic microbe.Keywords: Lactobacillus casei, probiotic, lactic acid bacteria, characterization,dadih ABSTRAKProduk probiotik merupakan salah satu aplikasi bioteknologi yang memanfaatkan bakteri asam laktat terutama jenis Lactobacillus. Beberapa syarat utama mikroba yang dapat difungsikan sebagai mikroba probiotik antara lain tahan terhadap pH rendah, mampu tumbuh pada garam empedu, mampu berkoloni, memiliki aktivitas antimikroba. Masing-masing spesies dari Genus Lactobacillus memiliki karakteristik yang berbeda-beda. Karakteristik ini sangat dipengaruhi oleh lingkungan dimana bakteri tersebut hidup. Pada penelitian ini telah dilakukan karakterisasi Lactobacillus casei yang merupakan hasil isolasi dari susu kerbau fermentasi. Dari hasil percobaan menunjukkan bahwa L.casei hasil isolasi mampu hidup sampai dengan konsentrasi garam empedu 15%, tahan terhadap media asam sampai dengan pH 2, memiliki aktivitas antimikroba (positif menghambat Escherichia coli, Staphylococcus aureus, dan Enterococcus faecalis). L. casei yang merupakan isolat lokal memiliki karakteristik yang berpotensi untuk digunakan sebagai mikroba probiotik.Kata kunci: Lactobacillus casei, probiotik, bakteri asam laktat, karakterisasi, dadih

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In vitro antibacterial activity of some spice extracts against methicillin-resistant Staphylococcus aureus isolated from nose of food handlers

International Journal of Pharmaceutical Research ◽

10.31838/ijpr/2020.12.03.412 ◽

2020 ◽

Vol 12 (03) ◽

Keyword(s):

Staphylococcus Aureus ◽

Antibacterial Activity ◽

Methicillin Resistant Staphylococcus Aureus ◽

Food Handlers ◽

Methicillin Resistant ◽

In Vitro Antibacterial Activity

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The Effects of Shock Vancomycin Concentrations on the Formation of Heteroresistance in Staphylococcus aureus

Antibiotics and Chemotherapy ◽

10.37489/0235-2990-2020-65-9-10-3-7 ◽

2020 ◽

Vol 65 (9-10) ◽

pp. 3-7

Author(s):

V. V. Gostev ◽

Yu. V. Sopova ◽

O. S. Kalinogorskaya ◽

M. E. Velizhanina ◽

I. V. Lazareva ◽

...

Keyword(s):

Staphylococcus Aureus ◽

In Vitro Selection ◽

Methicillin Resistant Staphylococcus Aureus ◽

High Concentration ◽

Short Term ◽

High Concentrations ◽

Selection Of ◽

Selection Of Resistance ◽

Test Cultures

Glycopeptides are the basis of the treatment of infections caused by MRSA (Methicillin-Resistant Staphylococcus aureus). Previously, it was demonstrated that antibiotic tolerant phenotypes are formed during selection of resistance under the influence of high concentrations of antibiotics. The present study uses a similar in vitro selection model with vancomycin. Clinical isolates of MRSA belonging to genetic lines ST8 and ST239, as well as the MSSA (ATCC29213) strain, were included in the experiment. Test isolates were incubated for five hours in a medium with a high concentration of vancomycin (50 μg/ml). Test cultures were grown on the medium without antibiotic for 18 hours after each exposure. A total of ten exposure cycles were performed. Vancomycin was characterized by bacteriostatic action; the proportion of surviving cells after exposure was 70–100%. After selection, there was a slight increase in the MIC to vancomycin (MIC 2 μg/ml), teicoplanin (MIC 1.5–3 μg/ml) and daptomycin (MIC 0.25–2 μg/ml). According to the results of PAP analysis, all strains showed an increase in the area under curve depending on the concentration of vancomycin after selection, while a heteroresistant phenotype (with PAP/AUC 0.9) was detected in three isolates. All isolates showed walK mutations (T188S, D235N, E261V, V380I, and G223D). Exposure to short-term shock concentrations of vancomycin promotes the formation of heteroresistance in both MRSA and MSSA. Formation of VISA phenotypes is possible during therapy with vancomycin.

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Group V Phospholipase A2 Mediates Endothelial Dysfunction and Acute Lung Injury Caused by Methicillin-Resistant Staphylococcus aureus

Cells ◽

10.3390/cells10071731 ◽

2021 ◽

Vol 10 (7) ◽

pp. 1731

Author(s):

Yu Maw Htwe ◽

Huashan Wang ◽

Patrick Belvitch ◽

Lucille Meliton ◽

Mounica Bandela ◽

...

Keyword(s):

Staphylococcus Aureus ◽

Acute Lung Injury ◽

Endothelial Dysfunction ◽

Lung Injury ◽

Phospholipase A2 ◽

Methicillin Resistant Staphylococcus Aureus ◽

Group V ◽

Methicillin Resistant

Lung endothelial dysfunction is a key feature of acute lung injury (ALI) and clinical acute respiratory distress syndrome (ARDS). Previous studies have identified the lipid-generating enzyme, group V phospholipase A2 (gVPLA2), as a mediator of lung endothelial barrier disruption and inflammation. The current study aimed to determine the role of gVPLA2 in mediating lung endothelial responses to methicillin-resistant Staphylococcus aureus (MRSA, USA300 strain), a major cause of ALI/ARDS. In vitro studies assessed the effects of gVPLA2 inhibition on lung endothelial cell (EC) permeability after exposure to heat-killed (HK) MRSA. In vivo studies assessed the effects of intratracheal live or HK-MRSA on multiple indices of ALI in wild-type (WT) and gVPLA2-deficient (KO) mice. In vitro, HK-MRSA increased gVPLA2 expression and permeability in human lung EC. Inhibition of gVPLA2 with either the PLA2 inhibitor, LY311727, or with a specific monoclonal antibody, attenuated the barrier disruption caused by HK-MRSA. LY311727 also reduced HK-MRSA-induced permeability in mouse lung EC isolated from WT but not gVPLA2-KO mice. In vivo, live MRSA caused significantly less ALI in gVPLA2 KO mice compared to WT, findings confirmed by intravital microscopy assessment in HK-MRSA-treated mice. After targeted delivery of gVPLA2 plasmid to lung endothelium using ACE antibody-conjugated liposomes, MRSA-induced ALI was significantly increased in gVPLA2-KO mice, indicating that lung endothelial expression of gVPLA2 is critical in vivo. In summary, these results demonstrate an important role for gVPLA2 in mediating MRSA-induced lung EC permeability and ALI. Thus, gVPLA2 may represent a novel therapeutic target in ALI/ARDS caused by bacterial infection.

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