Staphylococcus aureus is one of the notable human pathogens that can be easily encountered in both dietary and clinical surroundings. Among various countermeasures, bacteriophage therapy is recognized as an alternative method for resolving the issue of antibiotic resistance. In the current study, bacteriophage CSA13 was isolated from a chicken, and subsequently, its morphology, physiology, and genomics were characterized. This Podoviridae phage displayed an extended host inhibition effect of up to 23 h of persistence. Its broad host spectrum included methicillin susceptible S. aureus (MSSA), methicillin resistant S. aureus (MRSA), local S. aureus isolates, as well as non-aureus staphylococci strains. Moreover, phage CSA13 could successfully remove over 78% and 93% of MSSA and MRSA biofilms in an experimental setting, respectively. Genomic analysis revealed a 17,034 bp chromosome containing 18 predicted open reading frames (ORFs) without tRNAs, representing a typical chromosomal structure of the staphylococcal Podoviridae family. The results presented here suggest that phage CSA13 can be applicable as an effective biocontrol agent against S. aureus.

Clostridium perfringens is a Gram-positive, anaerobic, and spore forming bacterium that is widely distributed in the environment and one of the most common causes of foodborne illnesses. Bacteriophages are regarded as one of the most promising alternatives to antibiotics in controlling antibiotic-resistant pathogenic bacteria. Here we isolated a virulent C. perfringens phage, CPS1, and analysis of its whole genome and morphology revealed a small genome (19 kbps) and a short noncontractile tail, suggesting that CPS1 can be classified as a member of Picovirinae, a subfamily of Podoviridae. To determine the host receptor of CPS1, the EZ-Tn5 random transposon mutant library of C. perfringens ATCC 13124 was constructed and screened for resistance to CPS1 infection. Analysis of the CPS1-resistant mutants revealed that the CPF_0486 was disrupted by Tn5. The CPF_0486 was annotated as galE, a gene encoding UDP-glucose 4-epimerase (GalE). However, biochemical analyses demonstrated that the encoded protein possessed dual activities of GalE and UDP-N-acetylglucosamine 4-epimerase (Gne). We found that the CPF_0486::Tn5 mutant produced a reduced amount of capsular polysaccharides (CPS) compared with the wild type. We also discovered that glucosamine and galactosamine could competitively inhibit host adsorption of CPS1. These results suggest that CPS acts as a receptor for this phage.

Although the SnRK2 class of Ser/Thr protein kinases is critical for signal transduction and abiotic stress resistance in plants, there have been no studies to examine SnRK2 in Jatropha curcas L. In the present study, JcSnRK2 was cloned from J. curcas using the rapid amplification of cDNA end technique and characterized. The JcSnRK2 genomic sequence is 2578 base pairs (bp), includes 10 exons and 9 introns, and the 1017-bp open reading frame encodes 338 amino acids. JcSnRK2 was transcribed in all examined tissues, with the highest transcription rate observed in the roots, followed by the leaves and stalks; the lowest rate was observed in flowers and seeds. JcSnRK2 expression increased following abscisic acid treatment, salinity, and drought stress. During a 48-h stress period, the expression of JcSnRK2 showed 2 peaks and periodic up- and downregulation. JcSnRK2 was rapidly activated within 1 h under salt and drought stress, but not under cold stress. Because of the gene sequence and expression similarity of JcSnRK2 to AtSnRK2.8, primarily in the roots, an eukaryotic expression vector containing the JcSnRK2 gene (pBI121-JcSnRK2) was constructed and introduced to the Arabidopsis AtSnRK2.8 mutant snf2.8. JcSnRK2-overexpressing plants exhibited higher salt and drought tolerance, further demonstrating the function of JcSnRK2 in the osmotic stress response. J. curcas is highly resistant to extreme salt and drought conditions and JcSnRK2 was found to be activated under these conditions. Thus, JcSnRK2 is potential candidate for improving crop tolerance to salt and drought stress.

Bellflower root (Platycodon grandiflorum), which belongs to the Campanulaceae family, is a perennial grass that grows naturally in Korea, northeastern China, and Japan. Bellflower is widely consumed as both food and medicine owing to its high nutritional value and potential therapeutic effects. Since foodborne disease outbreaks often come from vegetables, understanding the public health risk of microorganisms on fresh vegetables is pivotal to predict and prevent foodborne disease outbreaks. We investigated the microbial communities on the bellflower root (n = 10). 16S rRNA gene amplicon sequencing targeting the V6-V9 regions of 16S rRNA genes was conducted via the 454-Titanium platform. The sequence quality was checked and phylogenetic assessments were performed using the RDP classifier implemented in QIIME with a bootstrap cutoff of 80%. Principal coordinate analysis was performed using the weighted Fast UniFrac distance. The average number of sequence reads generated per sample was 67,192 sequences. At the phylum level, bacterial communities from the bellflower root were composed primarily of Proteobacteria, Firmicutes, and Actinobacteria in March and September samples. Genera Serratia, Pseudomonas, and Pantoea comprised more than 54% of the total bellflower root bacteria. Principal coordinate analysis plots demonstrated that the microbial community of bellflower root in March samples was different from those in September samples. Potential pathogenic genera, such as Pantoea, were detected in bellflower root samples. Even though further studies will be required to determine if these species are associated with foodborne illness, our results indicate that the 16S rRNA gene-based sequencing approach can be used to detect pathogenic bacteria on fresh vegetables.