Aim:  The aims of the study were to isolate anti‐H9N2 bacteria from Korean Kimchi isolates and to evaluate its performance in cell line, egg and in specific pathogen‐free (SPF) chickens. Methods and Results:  Using Madin–Darby canine kidney (MDCK) cell line, 220 bacterial isolates were screened and the isolate YML003 was selected having pronounced antiviral activity against H9N2 virus. This isolate was identified as Leuconostoc mesenteroides by 16S rRNA gene sequencing. Anti‐H9N2 activity of the strain was also evaluated by hemagglutination assay. Leuconostoc mesenteroides YML003 was assessed for its survival in gastric juice and 5% bile acid and the antibiotic susceptibility. Both live and heat‐killed cells were selected for in vivo chicken feeding experiment. Body weight, immune index, serobiochemical parameters and splenic IFN‐γ production were assessed during selected intervals. Viral population in the trachea and cloacae were calculated by quantitative real‐time reverse transcriptase PCR (qRT‐PCR). Conclusions:  Leuconostoc mesenteroides YML003 exhibited anti‐H9N2 activity both in in vitro cell line as well as in vivo SPF Chickens. Significance and Impact of the Study:  This is a primary report on the anti‐H9N2 activity by a Leuconostoc strain. Amid the increasing reports of avian influenza virus occurrence resulting in severe losses to the poultry industry, prophylactic administration of such probiotic strains are highly significant.

Significance and Impact of the Study: After screening 1400 kimchi bacterial isolates, strain Lactobacillus plantarum YML007 was selected with strong antifungal activity against various foodborne pathogens. From the preliminary studies, it was found that the bioactive compound is a low molecular weight novel protein of 1256Á617 Da. Biopreservative potential of Lact. plantarum YML007 was demonstrated on soybean grains, and the results point out YML007 as a potent biopreservative having broad antimicrobial activity against various foodborne pathogens. AbstractKorean kimchi is known for its myriad of lactic acid bacteria (LAB) with diverse bioactive compounds. This study was undertaken to isolate an efficient antifungal LAB strain among the isolated kimchi LABs. One thousand and four hundred LABs isolated from different kimchi samples were initially screened against Aspergillus niger. The strain exhibiting the highest antifungal activity was identified as Lactobacillus plantarum YML007 by 16S rRNA sequencing and biochemical assays using API 50 CHL kit. Lact. plantarum YML007 was further screened against Aspergillus oryzae, Aspergillus flavus, Fusarium oxysporum and other pathogenic bacteria. The morphological changes during the inhibition were assessed by scanning electron microscopy. Preliminary studies on the antifungal compound demonstrated its proteinaceous nature with a molecular weight of 1256Á617 Da, analysed by matrix-assisted laser desorption ionization-time-of-flight mass spectrometry (MALDI-TOF). The biopreservative activity of Lact. plantarum YML007 was evaluated using dried soybeans. Spores of A. niger were observed in the negative control after 15 days of incubation. However, fungal growth was not observed in the soybeans treated with fivefold concentrated cell-free supernatant of Lact. plantarum YML007. The broad activity of Lact. plantarum YML007 against various food spoilage moulds and bacteria suggests its scope as a food preservative.

Lactic acid producing bacterial strain Probio-16 was isolated from the swine excrements under anaerobic conditions and characterized by morphology and biochemical characteristics. The strain was further identified by 16S rRNA gene sequencing and phylogeneitc analysis. The antimicrobial activity of the strain was assayed by testing for growth inhibition of thirteen pathogenic microorganisms. The strain was tested for antiviral activity against porcine rotavirus in vitro in African green monkey epithelial cell line TF-104. Antibiotic susceptibility of the strain against 13 antibiotics was tested using disk diffusion method. Phenotypically and through 16S rRNA gene sequences, Probio-16 was identified and named as Lactobacillus reuteri Probio-16. This strain was resistant to pH 2.0, 5% porcine bile and exhibited antimicrobial activity against all the thirteen enteric bacterial pathogens tested. Probio-16 supernatant inhibited porcine rotavirus in vitro in TF-104 cell lines. Except for erythromycin and penicillin G at a concentration of 4 microg/ml, Probio-16 showed resistance to all other thirteen antibiotics tested. This study indicates L. reuteri Probio-16 as a novel strain with its tolerance to low pH and bile, antimicrobial activity, antibiotic resistance and antiviral activity against rotavirus, and an ideal probiotic candidate for animal and human application after the proper in vivo experiments.

A total of 310 bacterial strains isolated from the porcine gastrointestinal tract were tested for their activity against transmissible gastroenteritis (TGE) coronavirus and other enteric pathogens. Based on activity, the strains Probio-38 and Probio-37 were selected as potential probiotics and identified as Lactobacillus plantarum Probio-38 and Lactobacillus salivarius Probio-37 respectively by 16S rRNA gene sequencing. Supernatants of these strains inhibited TGE coronavirus in vitro in ST cells, without any cytopathic effect even after 72 h of incubation. Both the strains exhibited high survival in synthetic gastric juice. The strains were resistant to 5% porcine bile and exhibited antimicrobial activity against all the 13 enteric bacterial pathogens tested. These strains also exhibited resistance to most of the antibiotics analyzed. The inhibition of transmissible gastroenteritis coronavirus and enteric bacterial pathogens as well as the bile tolerance, high survival in gastric juice, and the antibiotic resistance indicate that the two isolated bacterial strains are ideal probiotic candidates for animal application after proper in vivo experiments.

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