• The Journal of the Korean Society for Microbiology
• /
• v.22 no.1
• /
• pp.35-53
• /
• 1987

Multiply resistant Shigella strains isolated in Taegu area were subjected for the characterization of R plasmids. All strains isolated in 1984 and 1985 were susceptible to gentamicin, amikacin, and cephalothin, and most strains were susceptible to kanamycin (Km) and rifampin by agar dilution antimicrobial susceptibility test. The resistance frequency of S. flexneri against ampicillin (Ap) was higher than that of S. sonnei. The strains resistant to sulfisomidine (Su) and trimethoprim (Tp) were found at higher frequency in S. sonnei than in S. flexneri. The most prevalent resistance pattern of S. flexneri was chloramphenicol (Cm) tetracycline (Tc) streptomycin (Sm) Ap, followed by the pattern of CmTcSmSuApTp, CmTcSmSuApTp nalidixic acid, and CmTcSmSuAp in the decreasing order. The antibiogram of CmTcSmSuTp was found to be the most frequent pattern in S. sonnei. The ratio of conjugal transfer of S. flexneri was 47% and 75% of S. sonnei. The average number of plasmid harboring in Shigella was 4 and the size of plasmid ranged 1.3 to 134 megadalton (Mdal). Most S. flexneri carried plasmids of 2 to 3 Mdal and S. sonnei carried those of 3 to 4 Mdal size. The sizes of conjugative plasmids ranged 40-90 Mdal. The incompatibility group (Inc) F II plasmids (54-59 Mdal) were most frequent and rare Inc B plasmids (60 Mdal) of isolates in 1979 and 1980 and Inc FI (87 Mdal) of 1983 isolates were able to be classified by the colony test with standard reference plasmids. The R plasmids of known Inc group were tested for the restriction endonuclease analysis. The pattern of plasmids digested by EcoRl were apparently different by the Inc group but there was no significant difference between species or by the resistance patterns. Nonconjugative plasmids and their phenotypes were identified by transformation test. The transformants were resistant to less than two drugs. Colicin producing transformants carried the Col plasmid of 3.7 or 3.9 Mdal size. $Ap^r$ plasmids derived from S. sonnei were found to be mobilized by transfer factor RT641 to E. coli #CS100. $Ap^r$ plasm ids of same size shared by S. flexneri, S. sonnei, and E. coli were digested with Pstl. All of them showed two restriction fragments of 2.8 kilobase(kb) and 0.7kb. Other plasmids ($Sm^r\;Su^r$) derived from S. flexneri, S. boydii, and S. sonnei were digested with Pstl and they showed same restriction fragment patterns of 3.1kb and 2.9kb. The plasmid profiles of three strains of S. sonnei producing colicin and showing same resistance pattern of CmTcSmSuApTpKm appeared to be similar. Restriction patterns by EcoRl and the behavior of plasmids in conjugation or transformation process were also similar between those plasmids. The restriction patterns were significantly different between the plasmids of Inc FI group and those of unclassified Inc group.

• The Journal of the Korean Society for Microbiology
• /
• v.21 no.1
• /
• pp.73-95
• /
• 1986

A total of 5,462 isolates suspicious of Salmonella, Shigella and E. coli which were isolated during 1983 to 1985 by 12 City Hygine Laboratories and General Hospital Laboratories were received and identified at the National Salmonella Center, Seoul, Korea. The result of identification of these strains were summarized as follows: 1. It was confirmed that the total organisms broke down into 2,014 strains of Salmonella 1,294 of which were S. typhi, 887 strains of Shigella and 2,561 strains of E. coli. 2. For seasonal distribution of enteric pathogens, July was the month with the highest out breaks of salmonellosis, May was the month of Shigellosis, and April was of the highest month it in the case of E. coli. 3. Salmonella typhi with the highest incidence of isolation was shown to belong to various phage types, especially with the strains detected in Seoul. M1 type was widely distributed all over the country, but the majority was E1 type in 1983. 4. For age distribution of patients, the 20-29 age group had the highest incidence of salmonellosis whileas the 1 to 9 age group had the highest incidence of Shigellosis. 5. For sexuly distribution of Salmonella and Shigella infections seemed to be relatively higher in the female than in the male. However, E. coli. had no relationship to both sex. 6. The antibiotic sensitivity patterns of S. typhi cultures showed a tendancy to be resistant to colistin, gentamycin, neomycin, tetracycline and streptomycin. 7. The isolates of S. paratyphi-A, S. typhimurium and S. enteritidis seemed to have a tendency of multiple drug resistance. 8. 93.9 percent of 1,568 E. coli strains showed negative reactions to the antisera of enteropathogenic E. coli and 15.6 percent of them produced a heat-labile enterotoxin, but positive reaction to the antisera was 6.1 percent and 11.6 percent of them producled the enterotoxin.

• The Journal of the Korean Society for Microbiology
• /
• v.1 no.1
• /
• pp.26.1-26.1
• /
• 1958

• Journal of Microbiology
• /
• v.45 no.2
• /
• pp.168-170
• /
• 2007

In this research 26 Shigella isolates were examined by PCR and direct nucleotide sequencing for genetic alterations in the quinolone-resistance determining regions (QRDRs). We tested for the presence of qnr genes by PCR in 91 strains, but no qnr genes were found. The results did show, however, some novel mutations at codon 83 of gyrA ($Ser{\rightarrow}Ile$) and codon 64 of parC ($Ala64{\rightarrow}Cys,\;Ala64{\rightarrow}Asp$), which were related to fluroquinolone resistance.

• The Journal of the Korean Society for Microbiology
• /
• v.11 no.1
• /
• pp.23-26
• /
• 1976

The authors identified sixteen Shigella cultures, which were three cultures of subgroup A, ten cultures of subgroup B, three cultures of subgroup D and none of cultures belnoging to the subgroup C was detected as it was in previous year.

• Korean Journal of Pharmacognosy
• /
• v.22 no.1
• /
• pp.45-50
• /
• 1991

The combined effect of berberine isolated from the bark of Phellodendron amurense and some antibiotics was evaluated in order to measure the antibiotic activities. In this study, in the presence of streptomycin, tetracycline, cephradine as antibiotics, Staphylococcus aureus, Escherichia coli, Shigella sonnei as microorganisms were grown in an Automated Microbiology System. In case of Staphylococus aureus, combination with berberine and cephardine resulted in the strongest synergistic activity and in case of Escherichia coli and Shigella sonnei, combination with berberine and streptomycin resulted in the strongest synergistic activity. The combination with berberine and antibiotics increased the antibiotic activities, thereby showing a synergistic action.

• BMB Reports
• /
• v.32 no.5
• /
• pp.436-439
• /
• 1999

Shigella sonnei is an important cause of human enteric infections. S. sonnei KNIH104S was previously reported to be isolated from Korean shigellosis patients. We cloned a 2.8-kb KpnI fragment containing the recA gene encoding a recombinase from the chromosomal DNA of S. sonnei KNIH104S. This recombinant plasmid was named pRAK28. E. coli HB101, a recA mutant, cannot grow on Luria-Bertani medium in the presence of the alkylating agent methylmethane sulfonate, however, E. coli HB101 harboring pRAK28 was found to grow on this medium. As far as we know, we are the first to sequence the recA gene from S. sonnei. This gene is composed of 1062 base pairs with an ATG initiation codon and a TAA termination codon. Nucleotide sequence comparison of the S. sonnei recA gene exhibited 99.7% and 99.5% identity with those of S. flexneri and E. coli, respectively.

• The Journal of the Korean Society for Microbiology
• /
• v.21 no.4
• /
• pp.417-422
• /
• 1986

The specimens were collected from 89 diarrheal patients who had visited Pusan National University Hospital from June to September 1985. They were cultured and tested for the bacteriological identification of causative agents. In this study we identified 5 strains of Salmonella species, 5 strains of Shigella species, 2 strains of Y. enterocolitica, and 17 strains of enteric pathogenic E. coli. Enteric pathogenic E. coli were classified into enterotoxigenic E. coli, enteropathogenic E. coli, and enteroinvasive E. coli by serological type. We tried to isolate V. cholerae and V. parahaemolyticus too but we cannot find them out.

• Journal of Microbiology and Biotechnology
• /
• v.4 no.4
• /
• pp.245-249
• /
• 1994

An amino-terminal 14 amino acids deletion and three site-directed mutations were created to investigate the mechanism of induction and repression of MerR regulatory protein in R100 mer operon from gramnegative Shigella flexneri. The amino-terminal 14 amino acids deletion, Cysl17Ser, and Cys126Ser mutations abolished the inducibility of the mer operon and the Hisl18Ala mutation resulted in the reduction of inducibility (about 9.1 % remaining) in complementation experiment in the presence of $Hg^{2＋}$ at subtoxic level ($1\mu M$). The complementation experiment with $Hg^{2＋}$ absent showed that Hisl18Ala, Cys126Ser, and wild-type MerR could repress the operon but Cysl17Ser could not, and the amino-terminal deletion mutant could neither induce nor repress the R100 mer operon.

• YAKHAK HOEJI
• /
• v.56 no.5
• /
• pp.320-325
• /
• 2012

To develop a new effective and safe natural antibiotics and antioxidant the essential oil was extracted from the roots of Anthriscus sylvestris by steam distillation. Its composition was analyzed by GC-MS. The activities of the essential oil fraction and its main components were evaluated against antibiotic-susceptible and -resistant strains of some food-born bacteria. In addition the synergism was examined with this oil combined with antibiotic by checkerboard titer test. The antioxidant activities were determined by in 1,1-diphenyl-2-picryl-hydrazil (DPPH) free radical scavenging activity test and reducing power assay. The essential oil fraction of A. sylvestris revealed significant inhibiting activities against antibiotic-susceptible and -resistant species of Vibrio and Shigella with MICs ranged from 1.00~4.00 mg/ml. It showed synergistic or additive effects when it was combined with amphicillin or trimethoprim/sulfamethoxazole (1 : 9). Additionally, the essential oil fraction of A. sylvestris exhibited significant DPPH free radical scavenging activity and the reducing power.