Molecular Characteristics of Extended-Spectrum beta -Lactamases in Clinical Isolates of Enterobacteriaceae / 대한임상병리학회지

BACKGROUND: No significant information on the prevalence of extended-spectrum beta-Lactamase (ESBL)-producing Enterobacteriaceae in Korea has been available, because a few studies conducted to date in Korea have involved only discontinuous isolates of Klebsiella pneumoniae and Escherichia coli. In this study, a survey of clinical isolates of Enterobacteriaceae was carried out to assess the prevalence of ESBL-producing Enterobacteriaceae and to investigate the ESBL derivatives for phenotypical and genotypical characteristics. METHODS: A total of 500 consecutive clinical isolates of Enterobacteriaceae were screened for the presence of ESBL according to the new guidelines of the National Committee for Clinical Laboratory Standards. A double-disk synergy test, as a confirmatory test, was performed in screening positive strains. The presence of the ESBL gene was determined using polymerase chain reaction (PCR). The types of the beta-Lactamase gene were determined by isoelectric focusing and nucleotide sequence analysis. RESULTS: Among the collected strains, 21 of 293 E. coli (7.2%), 46 of 108 K. pneumoniae (42.6%), 10 of 20 Enterobacter cloacae (50.0%), 1 of 12 E. aerogenes (8.3%), 12 of 16 Citrobacter freundii (75.5%), and 1 of 14 Serratia marcescens (7.2%) were ESBL-producing strains. DNA sequencing and deduced amino acid sequence analysis revealed TEM-52 specific mutations in five strains (1 E. coli, 3 K. pneumoniae, and 1 E. cloacae) expressing pI 6.0 beta-Lactamases, SHV-2a in two K. pneumoniae of pI 7.6, and SHV-12 in four strains (1 E. coli of pI 8.2, 1 K. pneumoniae of pI 7.8, and 2 K. pneumoniae of pI 8.4). CONCLUSION: ESBLs were present in other genera of the family Enterobacteriaceae, such as Enterobacter, Citrobacter, and Serratia in Korea. ESBL types in E. coli isolates were TEM-52, SHV-12, and SHV-2a in decreasing order, and in K. pneumoniae isolates were TEM-52, SHV-2a and SHV-12 in decreasing order. The pIs of SHV-12 were 8.4 and 7.8 as well as 8.2, and a TEM-52 producing E. cloacae was first found.

Epidural Granulocytic Sarcoma involving the Thoracic Spine and Sternum in Acute Myelogenous Leukemia / 대한혈액학회지

Granulocytic sarcoma is a localized tumor composed of immature cells of the granulocytic series. Most granulocytic sarcomas occur in the course of acute leukemia and the blast crisis of chronic leukemia. Rarely, however, it may present before leukemia becomes clinically apparent. It may also occur in patients with myeloproliferative disorders. It has been reported that it occurs in 3% to 9% of patients with acute myelogenous leukemia (AML) and the incidence of granulocytic sarcoma is reported to be higher in patients with t (8;21). However, epidural granulocytic sarcoma associated with t (8;21) is very rare. In this report, we describe a patient with AML associated with t (8;21) in whom the cord compression occurred due to epidural granulocytic sarcoma. In addition, this case present infiltration of both pleura by blast cells. She was treated with local irradiation and chemotherapy successfully.