Effects of cell-free supernatant of Lactobacillus acidophilus LA5 and Lactobacillus casei 431 against planktonic form and biofilm of Staphylococcus aureus
This study was carried out to investigate the stability, antibacterial properties and biofilm removal potential of cell-free supernatant (CFS) of Lactobacillus acidophilus LA5 and Lactobacillus casei 431 against Staphylococcus aureus ATCC 25923. Antibacterial activity of both Lactobacillus strains was measured according to the agar spot method. The CFS was prepared by centrifugation of bacterial suspension at 4000 g for 10 min and the antimicrobial activity was measured using agar-well diffusion. The stability of CFSs during storage at 4.00 ± 2.00 °C and 25.00 ± 2.00 °C for a period of 4 weeks was measured based on the method of broth micro-dilution assay. Moreover, biofilm removal potential of CFS on 2-days-old biofilm of S. aureus developed on polystyrene and glass surfaces was also determined. The efficacy of CFS on bacterial biofilm established on the glass surface was also observed using fluorescence microscope. Results showed that inhibition zones of L. acidophilus (50.26 mm) were greater than L. casei (37.06 mm). The minimum inhibitory concentration of both CFSs remained stable (40 mg mL-1) during the storage for 28 days at 4.00 and 25.00 °C and storage temperature did not affect the antibacterial effectiveness of CFS. The addition of both CFSs significantly removed biofilm developed on both tested surfaces in a concentration-dependent manner. Biofilm removal property of L. acidophilus CFS was generally better than L. casei CFS which was confirmed by fluorescence microscope. The application of CFS of probiotic strains (i.e. Lactobacillus) as antibacterial and biofilm removal compounds could be very suitable to control the growth of food-borne pathogens.
The effect of Lactobacillus reuteri cell free supernatant on growth and biofilm formation of Paenibacillus larvae
Background: Paenibacillus larvae is the etiological agent of American foulbrood (AFB) disease, the most lethal disease in honeybee (Apis mellifera) larvae. Aims: The aim of the present work was to study the antimicrobial effect of cell free supernatant (CFS) of probiotics on an Iranian isolate’s biofilm formation. Methods: A l...متن کامل
ABSTRACT Background and objective: Considering the toxic side effects of chemotherapy in treatment of cancer, anticancer drugs of natural origin including probiotic Lactobacillus strains have recently attracted a lot of attention. Methods: After culturing chronic myeloid leukemia cell line K562 in 96-well plates, effects of different concentrations of ...متن کامل
Antibiofilm potential of Lactobacillus plantarum spp. cell free supernatant (CFS) against multidrug resistant bacterial pathogens
Biofilm formation is a major determinant factor in development of bacterial infections. In addition, bacteria embedded in a biofilm are more resistant to antimicrobials and thus the ability of bacteria to persist and grow in a biofilm seems to be the major factor for pathogenesis and therapeutic failure. In the current study, a Lactobacillus plantarum spp was isolated from Siahmazgi cheese, tra...متن کامل
The inhibitory effects of Lactobacillus fermentum, Lactobacillus acidophilus and Lactobacillus paracasei isolated from yoghurt on the growth and enterotoxin A gene expression of S. aureus
BACKGROUND: Staphylococcal foodborne intoxication is the most common cause of foodborne illnesses by Staphylococcus aureus strains and most are caused by the enterotoxins of S. aureus. Staphylococcal enterotoxin A (SEA) is the most frequently responsible for staphylococcal food poisoning outbreaks. From a food safety and human health point of view, lactic acid bacteria (LAB) may provide a promi...متن کامل
Effects of probiotic Lactobacillus acidophilus and Lactobacillus casei on colorectal tumor cells activity (CaCo-2).
BACKGROUND The probiotic microorganisms are live normal flora that provide nutritional benefits. When probiotic administered in adequate amounts, they also confer a health benefit on the host. Different mechanisms of probiotic effects include the following: stimulating the immune system, modifying the composition of normal intestinal flora and preventing the carcinogenic activity of fecal enzym...متن کامل
دوره 9 شماره 4
صفحات 301- 306
تاریخ انتشار 2018-12-15
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