Bean bug, Riptortus pedestris is an agriculturally serious pest in East Asian countries, reducing the value of crop quality and loss of income in agribusiness. Chemical pesticides have contributed to the management of the pest, but nowadays insect resistance limits the use of chemical pesticides, thus alternatively new pesticides with different mode of actions such as entomopathogenic fungi are considered. Beauveria bassiana and Metarhizium anisopliae JEF isolates were collected, identified and assayed against bean bugs in laboratory conditions. Some isolates showed >80% virulence by spray and contact-exposure methods. Supernatant showed different level of enzyme activity including chitinase, Pr1 protease and lipase. The Agrobacterium tumefaciens-mediated transformation generated random transformants and some mutants had reduced virulence. TAIL-PCR of the random transformants revealed virulence-related genes. This work can be a strong platform for the functional genetics of bean bug-pathogenic B. bassiana.

The ascomycete fungus Beauveria bassiana is a wide host range entomo- pathogenic fungus, which is commonly used as an environmental friendly biopesticide. However, the molecular mechanisms of host-pathogen interaction of B. bassiana are not well understood. Here, the high throughput next generation sequencing was performed to analyze the transcriptome of B. bassiana JEF-007 infected bean bug (Riptorus pedestris). Differentially expressed gene (DEG) analysis results showed that total 4,684 genes including 2,381 up and 2,303 down regulated genes were identified. Most of the DEGs were classified into single- organism, cellular and metabolism processes by gene ontology (GO) analysis. Metabolism pathway was the most abound category of DEGs via KEGG pathway mapping. Several possible candidates of virulence factors were dramatically expressed after infection, such as cytotoxic lectin, bacterial-like toxin, and proteins related to cell wall, hyphal growth, nutrient uptake and halogenated compounds synthesis. Furthermore, we also found the highest expression of a novel small RNA virus in the infected bean bug, but the relationship between fungal virulence and the RNA virus was under determination. The functional roles of these possible virulence factors are remained unclear, but this work provides a new insight for further fungal studies. Our results reflect systemic impacts of fungal pathogenesis and these findings represent a significant advance in the fungal functional genomics.

S. aureus is reported as a major cause of nosocomial infections after dental care and involved in endocarditis, bacteremia, osteomyelitis, peritonitis, and soft tissues etc. It is very important to identify the distribution and the diversity of toxin gene associated with the S. aureus expression in dental care patients with periodontitis directly for an effective prevention and treatment of dental diseases. Fifty four strains of S. aureus were isolated from the saliva of 129 patients who were diagnosed with periodontitis at dental clinics and hospitals located in Seoul. The distribution of the virulence gene and the genetic diversity of the strains were studied using the polymerase chain reaction with isolated strains. The enterotoxin test showed Seb was the most frequent gene with 88.9%. The hemolysin gene of Hla, Hib and Hld were the most frequently gene with 98.1% (53 strains), leukocidins gene of lukM showed 90.7% (49 strains), and laminin binding protein gene of Eno showed 100% (54 strains), respectively. The diversity of the enterotoxin gen was held as Seb-Seg-Sei gene of 35.2% (19 strains), the diversity of hemolysin gene of Hla-Hlb-Hld gene was 98.1% (53 strains) and the diversity of leukocidins gene of LukD-LukM were 88.9% (48 strains), respectively. Patients with dental disease showed somehow high toxin gene expression so that S. aureus in dental care area is judged to show very highly pathogen with a high and infection rate. In the future, additional studies for these toxin genes seem to be required.