Biomedical subjects

H J Cheong

Publications and source records attributed to H J Cheong.

5 recordsLinked to original sources

PubMed2001

Bacteremia due to quinolone-resistant Escherichia coli in a teaching hospital in South Korea.

Quinolone-resistant Escherichia coli (QREC) strains are being isolated with increasing frequency. From 1993 to 1998, 40 cases of QREC bacteremia were observed in a teaching hospital; 25 episodes (63.5%) were community-acquired. The incidence of QREC bacteremia increased steadily, from 6.7% to 24.6% during 5 years, and correlated with the significantly increased use of fluoroquinolones (P = .003, r = 0.98). When the 40 QREC bacteremic patients were compared with 80 patients with bacteremia due to quinolone-susceptible E. coli, prior fluoroquinolone use was the only independent risk factor for QREC bacteremia (P = .001). A high APACHE II score was the only independent risk factor for death. The rate of multidrug resistance of QREC was much higher (60%) than that of quinolone-susceptible isolates (13.8%). Pulsed-field gel electrophoresis patterns of these isolates were diverse. Therefore, the isolates revealed little evidence of clonal spread and may have emerged in direct response to the selective pressure exerted by prior fluoroquinolone use.

Anti-Bacterial Agents↗

PubMed1999

Pylephlebitis associated with appendicitis.

Pylephlebitis usually occurs secondary to infection in the region drained by the portal venous system. A most common antesecent focus of infection is diverticulitis and the most common blood isolate is E. coli (54%), followed by Proteus mirabilis (23%). Overall mortality is 32% and most of the patients who had died had severe sepsis prior to the initiation of antibiotic therapy. We describe a case of pylephlebitis which had appendicitis and consequent septic thrombosis of the portal vein and its branches, with dissemination of infection to the liver. The patient had recovered due to timely antibiotic treatment alone and resulted in complete resolution. Early diagnosis and treatment are basic to a favorable clinical course.

Adult↗

PubMed1998

A molecular epidemiologic study of methicillin-resistant Staphylococcus aureus infection in patients undergoing middle ear surgery.

The incidence of methicillin-resistant Staphylococcus aureus (MRSA) infections after middle ear surgery has recently increased at our hospital. Most of these infections were thought to be hospital-acquired when medical personnel in contact with an MRSA-infected patient may have inadvertently transmitted the pathogen to other patients. To prevent further transmission it is essential that such sources of MRSA infection and transmission routes be selected out and eradicated. Therefore, it is necessary to determine whether the strains of MRSA isolated from infected patients are identical to those obtained from medical personnel in order to prove a reciprocal transmission of organisms between medical personnel and patients. Surveillance bacterial cultures from the anterior nares and hands of medical personnel working in the Department of Otolaryngology, Korea University Guro Hospital, were performed at two different time points: 6 December 1994 and 17 June 1996. Ribotyping with Southern blot technique was used to compare 12 MRSA strains from medical carriers with 60 strains identified from the otorrhea of MRSA-infected patients undergoing middle ear surgery. As results, six different MRSA strains were identified (types I, II, III, IV, V and VI) from ribotyping with EcoR1. One distinct subtype, type I strain, was the most frequently identified strain in both medical carriers and patients. Results also showed that 6 MRSA isolates from 10 medical carriers and 20 from 30 patients contained type I ribotype at first culture. Two medical carriers' isolates and 13 isolates from 30 patients shared the same type I strain at the second surveillance culture. In all, 41 out of 72 MRSA strains (56.9%) shared an identical ribotype pattern. Postoperative MRSA infection rates after treatment of medical carriers and the application of rigorous preventive procedures decreased from 11.9 to 5.7% after first culture and 9.0 to 7.7% following second cultures. These findings confirm that MRSA transmission can occur between medical personnel and patients and that effective preventive measures can reduce the postoperative infection rate.

Blotting, Southern↗

PubMed1998

Nested polymerase chain reaction for detection of Mycobacterium tuberculosis in solitary pulmonary nodules.

BACKGROUND: Differential diagnosis of solitary pulmonary nodules (SPNs) can be difficult in areas, such as Korea, where tuberculosis is endemic. Nested polymerase chain reaction (PCR) is a widely used method to test a very small amount of pathogen and to detect Mycobacterium tuberculosis from fine needle aspirates. OBJECTIVES: The usefulness of nested PCR for the detection of M tuberculosis from tuberculous SPN and for the differential diagnosis of SPN was evaluated. METHODS: Thirty-three patients in whom a diagnosis of SPN was made based on a CT scan of the chest were enrolled in this study. Included were 17 malignant and 16 benign SPNs. Nested PCR was carried out for the detection of M tuberculosis by using TB-1, TB-2, TB-28, and TB-29C on fine needle aspirates from the nodule in all 33 cases. RESULTS: Aspirates from malignant neoplasms, pneumonia, and sequestration were all negative on nested PCR for tuberculosis. One of the three radiologically suspected tuberculous nodules without response to anti-tuberculosis drugs (uncertain) yielded positive results on nested PCR for the detection of M tuberculosis. In contrast, 7 out of 8 (87.5%) aspirates from proven tuberculous nodules showed positive results on nested PCR. Nested PCR could be used to detect M tuberculosis in fine needle aspirates from tuberculous SPNs with good sensitivity (87.5%) and specificity (96.0%). CONCLUSION: Nested PCR for the detection of M tuberculosis in fine needle aspirates may be useful in the differential diagnosis of SPNs.

Biopsy, Needle↗

PubMedDate not supplied

Possibility of reciprocal infection of methicillin-resistant Staphylococcus aureus between medical personnel and patients undergoing middle ear surgery.

The incidence of methicillin-resistant Staphylococcus aureus (MRSA) infection after middle ear surgery has recently increased in our hospital. In this study we tried to determine whether the strains of MRSA isolated from infected patients are identical to those obtained from medical personnel, to prove a reciprocal transmission between medical personnel and patients. Surveillance bacterial cultures of medical personnel were performed from the anterior nares and from the fingertip. Molecular epidemiological studies, ribotyping and pulsed-field gel electrophoresis (PFGE) were used to compare the 12 MRSA strains obtained from carriers among medical personnel with the 60 strains identified from patient's otorrhea. Six different MRSA strains were identified from ribotyping, and three subtypes from PFGE. There was a particular subtype which was the most frequently identified strain found in both medical carriers and patients. Postoperative MRSA infection rates after the treatment of medical carriers and application of preventive procedures decreased from 11.9 to 5.7%. These findings suggest that the MRSA transmissions have occurred between medical personnel and patients.

Cross Infection↗