Epidemiology of Shigellosis in Korea

Shigellosis is an acute diarrheal disease caused by bacteria of the genus Shigella. Following the occurrence of a large outbreak of shigellosis as well as sporadic cases since 1998, shigellosis has been a major health problem in Korea. There have been major changes in epidemiology during the last five decades concerning shigellosis in terms of total incidence of shigellosis, prevalence of certain serogroups, selection of specific clones, and introduction of new Shigella clones. S. dysenteriae was the most prevalent species until the early twentieth century, S. flexneri was the most prevalent until the late 1980s, and S. sonnei has been the most prevalent since 1990. Diverse serotypes of S. dysenteriae (4 serotypes), S. flexneri (8 serotypes), and S. boydii (4 serotypes) were found during the Korean War and many of these Korean endemic Shigella strains circulated in the community until the late 1970s. However, the endemic strains of S. dysenteriae, S. boydii, and S. sonnei disappeared in the late 1980s. A new clone of S. sonnei that was introduced between the late 1980s and the early 1990s was responsible for a large proportion of shigellosis in recent years. S. flexneri serotype 4a was the most frequently found during the Korean War and then the incidence of S. flexneri 2a gradually increased with time. S. flexneri isolates detected from 1991 to 1997 were all serotype 2a. However, the diverse clones of S. flexneri reemerged in Korea since 1999. It has not been determined whether the S. flexneri strains from the 2000s were the descendants of the Korean endemic strains or imported new strains, but the PFGE patterns were different between S. flexneri strains from the 1980s and 2000s. The widespread of new S. sonnei strains and the persistence of S. flexneri strains are responsible for the endemicity of shigellosis in Korea.

Molecular Epidemiology of Nalidixic Acid Resistance in Shigella sonnei Isolates

Twenty-six nalidixic acid-resistant Shigella sonnei strains isolated from 1982 to 2001 and 56 nalidixic acid-resistant mutants induced by quinolone drugs from susceptible wild strains were analyzed by sequencing the gyrA gene. All the 22 nalidixic acid-resistant isolates from 1998 to 2001 showed identical amino acid substitution of Ser to Leu (TCG --> TTG) at codon 83 while 7 different mutation types were detected in artificially induced nalidixic acid-resistant mutants. Asp87 (GGC) type was observed most commonly among mutants induced by nalidixic acid while Ser83 (TTG) type was common among mutants induced by ciprofloxacin or norfloxacin. All the isolates collected between 1998 and 2001 showed identical or nearly identical pulsed-field gel electrophoresis pattern. These results suggest that the explosive increase of S. sonnei infection after 1998 was mainly due to the spread of restricted number of clones resistant to nalidixic acid.

Prevalence of Specific Clone of Salmonella enterica Serovar Typhimurium Clones in the Swine Population of Kyungpook Province During 1998 to 2000

A total of 40 Salmolella enterica serovar Typhimurium (S. typhimurium) strains were isolated from clinical specimens of swine at 10 farms in Kyungpook province from 1998 to 2000. We investigated the clonal relationship of S. typhimurium isolates by antimicrobial susceptibility, plasmid profile, and Southern hybridization analysis with tetA, and pulsed-field gel electrophoresis (PFGE). All S. typhimurium isolates showed identical biochemical characteristics and were resistant to tetracycline, streptomycin, and sulfamehtoxazole. They were classified into 5 groups by antimicrobial resistance patterns. S. typhimurium isolates carried 3 to 5 plasmids and were classified into 5 groups by plasmid profiles. Southern hybridization showed that tetA gene was located in 21 kb of plasmid. S. typhimurium isolates from 9 different farms showed identical or similar PFGE patterns, which indicates clonal origin of the strains. All S. typhimurium isolates, except one isolate from 1998, seemed to belong to be one clone by the combination of three epidemiological typing methods. These data demonstrated that a specific clone of Salmolella enterica serovar Typhimurium was widely spread in swine farms in Kyungpook province.

Epidemiologic analysis of Ampicillin Resistance in Shigella sonnei Isolates by blaTEM Hybridization

Forty-seven ampicillin-resistant R plasmids derived from 218 Shigella sonnei isolates from Daegu and Gwangju areas from 1980 to 2000 were epidemiologically compared by fragments of restriction endonuclease patterns by EcoRI and SmaI, and by Southern hybridization with a blaTEM-1 probe. All the ampicillin-resistant strains isolated in the 1980S carried a conjugative R plasmid responsible for multiple resistance other than ampicillin, and an ampicillin-resistance plasmid. Ampicillin-resistant strains isolated in the 1990S harbored single conjugative R plasmid encoding ampicillin resistance along with variable antimicrobial resistances. The restriction endonuclease digestion patterns and Southern hybridiztion analysis of conjugative R plasmids showing identical resistance pattern and a same size showed different fragment and Western blotting patterns according to different isolation years and areas, while identical patterns were observed among the plasmids derived from a same isolation year and area. These findings suggest that ampicillin resistance among S. sonnei isolates was due to introduction of ampicillin-resistant R plasmids originated from different sources.

The Relationship Among Mother-Daughter Relationship, Husband-Wife Relationship and Prenatal Attachment according to Pregnant Women's Internal Working Model / 여성건강간호학회지

PURPOSE: The purpose of this study was to identify the relationship among mother-daughter relationship, husband-wife relationship, and prenatal attachment according to pregnant women's internal working model. METHOD: A convenience sample of 68 pregnant women was recruited from two OBGYN hospitals in M city. Data collection was conducted through the use of an Adult Attachment Interview and questionnaires. This study used a descriptive correlational design and the period of investigation was from July 3-20, 2002. 41 of the 68 women were in a secure pregnant women's internal working model and 27 of the 68 in insecure ones. The data were analyzed by Chi-square test, t-test, and Pearson Correlation Coefficient. RESULT: The results of this study were as follows: Mean score of the prenatal attachment of the secure pregnant women and mean score of the mother-daughter relationship of the secure pregnant women was significantly higher than that of insecure ones. 3) Prenatal attachment was negatively and significantly related to mother-daughter attachment and husband-wife attachment in the secure pregnant women's internal working model. However it was not significantly relationship in insecure pregnant women's internal working model. CONCLUSION: It is found in this study that there is an intergenerational attachment relationship during pregnancy. Further findings support the development of creative strategies to enhance positive attachment relationships for pregnant women. It is recommended to develop nursing education of attachment for the insecure pregnant women's internal working model.

Epidemiologic analysis of Shigella sonnei Isolates by using Antimicrobial Resistance Gene Probes

Thirty-four Shigella sonnei isolates from 6 outbreaks and sporadic cases from May 1999 until January 2000 in Daegu and 9 regions of Gyeongsangbuk-Do were epidemiologically analyzed by plasmid profiling, pulsed-field gel electrophoresis (PFGE), and hybridization with 2 antimicrobial resistance gene probes, tetA and dfrA1. In outbreak cases, resistance pattern in all of the strains was identical: they were resistant to tetracycline (Tc), streptomycin (Sm), sulfisomidine (Su), trimethoprim (Tp), and nalidixic acid (Na). In sporadic cases, Tc, Sm, Su, Na, ampicillin (Ap), and kanamycin (Km) pattern and TcSmSuTpApNa pattern were additionally observed. Isolates from the same outbreak showed identical plasmid profile and PFGE pattern. Most of different outbreak strains and sporadic strains showed different plasmid profiles, and identical or different PFGE patterns, while all of the isolates shared common tetA gene on a non-conjugative 18.3 kbp R plasmid carrying resistance to tetracycline, streptomycin, and sulfisomidine, and dfrA1 gene on the chromosome. Non-conjugative R plasmids derived from all of the isolates were confirmed to be identical by the Southern hybridization analysis of restriction endonuclease treated or non-treated plasmid profiles using the tetA probe. The same strains also reacted with dfrA1 probe at the same-sized DNA fragment (60 kbp) on pulsed-field gel electrophoresis of total genomic DNA. Our findings suggested that epidemic strains of Shigella sonnei prevalent in the Daegu and Gyeongsangbuk-Do area during the test period should have originated from an identical or closely related strain source although most of strains did not show the same plasmid profile and PFGE pattern.

Molecular Epidemiology of Shigella sonnei Isolated from 1994 to 1999 in Daegu area

A total of 78 Shigella sonnei strains isolated from 1994 to 1999 in Daegu were screened by biochemical test, antimicrobial susceptibility test, plasmid profiling, and epidemiologic analysis. Among them, 26 representative strains with different properties were selected and their molecular epidemiological characteristics were studied. Among the 78 strains, two strains did not ferment raffinose and another two strains did not produce colicin. The 26 selected strains were differentiated into 15 plasmid profiles, 11 antimicrobial, 14 enterobacterial repetitive intergenic consensus sequencebased PCR (ERIC-PCR) pattern, 10 pulsed-field gel electrophoresis (PEGE) pattern types. When all of the typing methods were combined, the strains could be differentiated into 15 types. However, significant correlation among different testing methods was not observed. PEGE analysis indicated that all the strains tested were related despite minor genotypic and phenotypic differences. Our data could not address whether these genetic diversity of strains is due to different circulating strains originated from a number of clone or due to minor genetic variation.

Effect of imipramine on calcium utilization of single cells isolated from canine detruso

This study is to investigate the mechanism of inhibitory effect of imipramine on the calcium utilization in single cells isolated from canine detrusor. 2 mm thick smooth muscle chops were incubated in 0.12% collagenase solution at 36degreeC, and aerated with 95% O2/5% CO2, and then cell suspension was examined Acetylcholine (ACh) evoked a concentration-dependent contraction of the isolated detrusor cells in normal physiologic salt solution (PSS), and the ACh-induced contraction was significantly inhibited by imipramine. In Ca2+-free PSS, ACh-induced contraction was less than those in normal PSS and it was not affected by the pretreatment with imipramine. Ca2+-induced contraction in Ca2+-free PSS was supressed by imipramine, but addition of A 23187, a calcium ionophore, overcomed the inhibitory effect of imipramine. High potassium-depolarization (40 mM KCl) evoked cell contraction, which was inhibited by imipramine. Caffeine, a releasing agent of the stored Ca2+ from sarcoplasmic reticulum, evoked a contraction of the cells that was not blocked by the pretreatment with imipramine. These results suggest that imipramine inhibits the influx of calcium in the detrusor cells through both the receptor-operated- and voltage-gated-calcium channels, but does not affect the release of calcium from intracellular storage site.

Clinical Competency for Directing of Registered Nurses's National Examination: focused on Fundamental, Medical-Surgical, Psychiatric, women's health, community, Pediatric, and Administrative Nursing / 간호학회지

For producing large numbers of professional nurses who could manage 21th century's human health, it is necessary to review the direction of registered nursed' national examination which evaluates the nursing education and is granted a licence. For adapting to social expectation of the nurse, we have to nurture the nurses' problem solving capability in clinical setting. Seven divisions of Korean Academy of Nursing suggested clinical competency according to their categories. This paper was presented in the workshop for setting up direction of registered nurses' national examination. We expect that this paper would be more refine and confirm through reviewing subdivisions' learning objectives and discussing clinical minimum level of competence contents with clinical leaders.