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Biomedical subjects

Teruyo Ito

Publications and source records attributed to Teruyo Ito.

22 records · Page 2Linked to original sources

A novel methicillin-resistance cassette in community-acquired methicillin-resistant Staphylococcus aureus isolates of diverse genetic backgrounds.

Until recently, it has been unclear whether community-acquired (CA) methicillin-resistant Staphylococcus aureus (MRSA) isolates represent the spread of hospital MRSA isolates into the community. In 2 CA-MRSA isolates, a novel genetic element, designated staphylococcal cassette chromosome mec (SCCmec) type IV, was found; it differs from SCCmec types I-III in its small size and absence of non-beta-lactam genetic-resistance determinants. To study the prevalence of type IV SCCmec, polymerase chain reaction characterization of SCCmec was performed on DNA from 12 CA-MRSA isolates. The 12 CA-MRSA isolates were from diverse genetic backgrounds, as evidenced by their stratification into 5 pulsed-field gel electrophoresis types, 4 coagulase types, and 2 ribotypes. Eleven of the 12 isolates contained the novel SCCmec type IV element. Ten were resistant only to beta-lactam antibiotics. SCCmec type IV is present on the genome of CA-MRSA isolates. Its relatively small size and presence in isolates of diverse genetic backgrounds suggest that it may spread among S. aureus isolates.

Community-Acquired Infections↗

Molecular genetics of methicillin-resistant Staphylococcus aureus.

A large and growing proportion of Staphylococcus aureus clinical isolates are methicillin resistant, and are resistant to practically all beta-lactam antibiotics. Methicillin-resistant S. aureus (MRSA) strains harbor mecA, which is carried by a unique mobile genetic element, staphylococcal cassette chromosome mec (SCCmec) integrated into the S. aureus chromosome. The mecA gene encodes a methicillin-insensitive transpeptidase, the production of which confers resistance to otherwise inhibitory concentrations of beta-lactam antibiotics. Several distinct clones have been identified among MRSA that apparently have been generated by integration of distinct types of SCCmec. While MRSA are primarily nosocomial pathogens, recent observations indicate that other MRSA clones are colonizing a significant proportion of healthy individuals in the community as well. Community-acquired MRSA (C-MRSA), may become a new threat to humans, and international cooperation of researchers and clinicians will be of cardinal importance in addressing this problem.

Bacterial Proteins↗

Novel type of staphylococcal cassette chromosome mec identified in community-acquired methicillin-resistant Staphylococcus aureus strains.

We identified a new type of staphylococcal cassette chromosome mec (SCCmec) from two community-acquired methicillin-resistant Staphylococcus aureus (MRSA) strains. The novel element, designated type IV SCCmec, had a unique combination of the class B mec gene complex and the type 2 ccr gene complex and was much smaller in size (21 to 24 kb) than previously identified SCCmec elements of hospital-acquired MRSA. Consistent with the strains' susceptibilities to various non-beta-lactam antibiotics, the type IV SCCmec was devoid of any antibiotic resistance genes other than the mecA gene.

Anti-Bacterial Agents↗

Dissemination of new methicillin-resistant Staphylococcus aureus clones in the community.

Multiple methicillin-resistant Staphylococcus aureus (MRSA) clones carrying type IV staphylococcal cassette chromosome mec were identified in the community-acquired MRSA strains of both the United States and Australia. They multiplied much faster than health-care-associated MRSA and were resistant to fewer non-beta-lactam antibiotics. They seem to have been derived from more diverse S. aureus populations than health-care-associated MRSA strains.

Anti-Bacterial Agents↗