• Korean Journal of Veterinary Research
• /
• v.34 no.3
• /
• pp.511-516
• /
• 1994

P multocida was isolated from 80(17.7%) of 450 pneumonic lungs of slaughter pigs. The majority of the biochemical and cultural characteristics of P multocida isolates were identical to those of the reference strains employed. Seventy seven strains(96.3%) among 80 isolates were capsular serotype A while the remaining 3(3.8%) were serotype D. All isolates were very susceptible to ampicillin, ceftiofur, cephalothin, ciprofloxacin and penicillin-G although some of them were resistant to sulfamethoxin and/or streptomycin. Sixty one(76.3%) of all 80 P multocida isolates were dermonecrotic toxin producers. Out of 77 isolates of serotype A and 3 isolates of serotype D, 59(76.6%) and 2(66.7%) were toxigenic, respectively. No difference was noted in dermonecrotic toxigenicity of the isolates in relation to capsular serotypes.

• Journal of Microbiology and Biotechnology
• /
• v.15 no.6
• /
• pp.1197-1206
• /
• 2005

Vibrio vulnificus is an opportunistic pathogen that causes a septicemia and expresses numerous virulence factors, in which luxS and smcR are genes encoding for components responsible for quorum-sensing regulation. In the present study, null mutants were constructed with lesions in each or both of these two genes from the V. vulnificus Vv$\Delta$Z strain, which is a lacZ$^{-}$ and chloramphenicol/streptomycin-resistant derivative of the wild-type ATCC29307 strain, and their phenotypes related to virulence were compared with those of the parental cells. $LD_{50}$ and histopathological findings of luxS-, smcR-, or luxS- smcR- deficient mutant were not different from those of the parent strain, a lacZ-deficient streptomycin-resistant strain in mice. However, time of death in mice was delayed, and numbers of bacteria survived in bloodstream after intraperitoneal injection in mice were decreased by mutation, especially luxS and smcR double mutant (VvSR$\Delta$ZSR). These phenomena were supported by increased serum sensitivity and delayed bacterial proliferation in both murine blood and iron-restricted medium. These results suggest that the luxS and luxR homologous genes in V. vulnificus could playa role in bacterial survival in host by enhancing proliferation and adjusting to changed environment.

• Journal of Food Hygiene and Safety
• /
• v.22 no.4
• /
• pp.294-299
• /
• 2007

Eighty seven strains were isolated from 164 dried marine products(dried squid and dried alaska pollack etc) in Seoul Garak wholesale market. Among 87 isolates, twenty four E. faecalis and 4 E. faecium were identified by API strep kit. Twenty eight strains of E. faecalis, and E. faecium were resistant in streptomycin (95.6%), kanamycin (84.5%), gentamycin (66.7%), cephaloxin (97.8%), ampicillin/sulbactam (88.9%), ticarcillin(66.7%), amikacin (97.8%), sulfonamides (97.8%), ceftriaxone (75.6%), nalidixic acid (100.0%), and cefoxitin (100.0%), and were susceptible in amoxicillin/clavulanic acid(97.8%), chloramphenicol(95.6%), sulfamethoxazole/trimethoprim (97.8%), and tetracycline (71.1%). Also, ten strains of E. faecalis was resistant in $S-K-GM-CF-SAM-TIC-An-S_3-CRO-NA-FOX$ drugs simultaneously. Conclusively, E. faecalis strains from dried marine products were resistant on antibiotic drugs residue.

• Clinical and Experimental Pediatrics
• /
• v.61 no.2
• /
• pp.49-52
• /
• 2018

Purpose: Tularemia is an infection caused by Francisella tularensis. Its diagnosis and treatment may be difficult in many cases. The aim of this study was to evaluate treatment modalities for pediatric tularemia patients who do not respond to medical treatment. Methods: A single-center, retrospective study was performed. A total of 19 children with oropharyngeal tularemia were included. Results: Before diagnosis, the duration of symptoms in patients was $32.15{\pm}17.8days$. The most common lymph node localization was the cervical chain. All patients received medical treatment (e.g., streptomycin, gentamicin, ciprofloxacin, and doxycycline). Patients who had been given streptomycin, gentamicin, or doxycycline as initial therapy for 10-14 days showed no response to treatment, and recovery was only achieved after administration of oral ciprofloxacin. Response to treatment was delayed in 5 patients who had been given ciprofloxacin as initial therapy. Surgical incision and drainage were performed in 9 patients (47.5%) who were unresponsive to medical treatment and were experiencing abcess formation and suppuration. Five patients (26.3%) underwent total mass excision, and 2 patients (10.5%) underwent fine-needle aspiration to reach a conclusive differential diagnosis and inform treatment. Conclusion: The causes of treatment failure in tularemia include delay in effective treatment and the development of suppurating lymph nodes.

• Microbiology and Biotechnology Letters
• /
• v.30 no.2
• /
• pp.129-134
• /
• 2002

To isolate probiotic lactic acid bacteria having superior inhibitory activities against animal gastro-intestinal pathogenic bacteria such as Salmonella gallinarum, Staphylococcus aureus and Escherichia coli, 130 strains were initially isolated from the small intestines of Korean native chickens and 7 lactic acid bacteria were finally selected. By using API CHL kit and 16S rRNA sequencing method, the selected lactic acid bacteria were found to be belonged to genus Lactobacillus except BD14 identified as Pediococcus pentosaceus. Especially, Lactobacillus pentosus K34 showed the highest resistancy to both of HCl and bile salt, as well as the highest inhibitory activities against S. gallinarum, S. aureus and E. coli. All the selected strains were sensitive to various antibiotics such as neomycin, erythromycin, cephalosporin, amoxicillin/clavulanic acid, ampicillin, oxytetracycline, but resistant to ciprofloxacin. All the selected strains except BL strain were resistant to colistin and streptomycin, and BD14, BD16, K34 strains were resistant to gentamicin.

• Journal of Plant Biology
• /
• v.34 no.1
• /
• pp.37-43
• /
• 1991

Mesophyll protoplasts of Nicoliana labacum ($NR^{-}/SR^{+}$) and N glulinosa were electrofused with AC field of 0.5 MHz and 1 kV DC pulse for 2 ms. Fused protoplasts were selected and cultured to the green cell clusters in $MSNO_3$ medium containing 1.2 mg!ml streptomycin sulfate. Four plant lines regenerated from selected colonies showed both parental morphological characteristics of leaf and flower and these plant lines were confirmed as somatic hybrids based on electrophoretic patterns of leaf peroxidase. In XhoI restriction patterns of chloroplast DNA, these hybrid plant lines expressed both parent common restriction sites and parent specific sites. One of these hybrid lines exhibited interspecific pattern of both parental chloroplast genomes. indicating nine both parent common sites, one N labacum specific site and two N glutinosa specific sites. sites.

• Research in Plant Disease
• /
• v.24 no.1
• /
• pp.59-65
• /
• 2018

Pyraclostrobin is a broad-spectrum fungicide that inhibits mitochondrial respiration. However, it may also induce systemic resistance effective against bacterial and viral diseases. In this study, we evaluated whether pyraclostrobin enhanced resistance against the bacterial spot pathogen, Xanthomonas euvesicatora on pepper (Capsicum annuum). Although pyraclostrobin alone did not suppressed the in vitro growth of X. euvesicatoria, disease severity in pepper was significantly lower by 69% after treatments with pyraclostrobin alone. A combination of pyraclostrobin with streptomycin reduced disease by over 90% that of the control plants. The preventive control of the pyraclostrobin against bacterial spot was required application 1-3 days before pathogen inoculation. Our findings suggest that the fungicide pyraclostrobin can be used with a chemical pesticide to control bacterial leaf spot diseases in pepper.

• Korean Journal of Veterinary Research
• /
• v.19 no.1
• /
• pp.75-83
• /
• 1979

The sensitivities of 270 pathogens (124 Streptococci, 118 Staphylococci, 10 Corynebacterium pyogenes and 18 Escherichia coli) isolated from clinical or subclinical cases of bovine mastitis during lactation to 11 antibiotics were determined by the agar plate dilution method. All cultures of Streptococci were inhibited at $1.56{\mu}g/ml$ of ampicillin and 1.56 units/ml of penicillin G. Most of the cultures were inhibited at $3.125{\mu}g/ml$ of leukomycin, but were resistant to kanamycin, streptomycin, chloramphenicol, erythromycin and colistin at concentration of $12.5{\mu}g/ml$. More than 93% of the Staphlococcal cultures were sensitive to kanamycin, leukomycin, ampicillin, tetracycline, ledermycin and minocycline at concentrations of $12.5{\mu}g/ml$ or less, and sensitive to penicillin at concentration of 3.125 units/ml, but for more than 71% of the cultures to chloramphenicol, erythromycin and colistin the concentrations required to inhibit growth were 100 ${\mu}g/ml$ or higher. All 10 cultures of Corynebacterium pyogenes were inhibited by leucomycin, ampicillin and minocycline at concentration of $1.56{\mu}g/ml$ and by penicillin G at concentration of 0.78 units/ml, but all the cultures required at least $400{\mu}g/ml$ or higher of streptomycin, erythromycin and colistin for inhibition. More than 83% of E. coli cultures were sensitive to erythromycin and minocycline at concentration of $12.5{\mu}g/ml$, but resistant to leucomycin and chloramphenicol at concentration of $100{\mu}g/ml$.

• Journal of Food Hygiene and Safety
• /
• v.35 no.2
• /
• pp.189-194
• /
• 2020

In this study, we investigated the efficacy of Salmonella phage P22 combined with antibiotics to inhibit antibiotic-resistant S. Typhimurium CCARM 8009. The synergistic effect of phage P22 and antibiotics was evaluated by using disk diffusion and broth dilution assays. The development of Antimicrobial resistance was determined after time-kill assay. The antibiotic susceptibility assay showed the inhibition zone sizes around the antibiotic disks were increased up to 78.8% in the presence of phage (cefotaxime; 13.6%, chloramphenicol; 19.3%, ciprofloxacin; 12.7% and erythromycin; 78.8%). The minimum inhibitory concentration values of the combination treatment significantly decreased from 256 to 64 mg/mL for tetracycline, 8 to 4 mg/mL for chloramphenicol, 0.0156 to 0.0078 mg/mL for ciprofloxacin, 128 to 64 mg/mL for erythromycin and 512 to 256 mg/mL for streptomycin. The number of S. Typhimurium CCARM 8009 was approximately 4-log lower than that of the control throughout the combination treatment with phage P22 and ciprofloxacin delete at 37℃ for 20 h. The results indicate that the development of antimicrobial resistance in S. Typhimurium could be reduced in the presence of phage treatment. This study provides promising evidence for the phage-antibiotic combination as an effective treatment to control antibiotic-resistant bacteria.

• The Journal of the Korean Society for Microbiology
• /
• v.16 no.1
• /
• pp.1-5
• /
• 1981

Shigella is one of the most prevalent pathogens for the diarrhoeal diseases in the developing countries. One hundered and six strains of shigella were isolated from January 1980 to August 1981 at the dept. of clinical pathology, Han Yang Medical Center. Subgroups of these strains were identified as one strain of S. dysenteriae, 98 strains of S. flexneri and 7 strains of S. sonnei. None of S. boydii was observed. Sex ratio, male to female was 48 to 58. Age distribution disclosed 6 cases under one year, 11 cases one to under 2 years and 21 cases(19.8%) two to under 3 years. Subtotal of 0 to 9 years showed 64 cases(60.4%). Susceptibility for antibiotics of these strains revealed dibekacin 100%, sisomicin 100%, amikacin 98.1%, cefazolin 97.2%, tobramycin 97.1%, gentamicin 95.2%, colistin 93.0%, minocycline 89.6%, kanamycin 83.0%, carbenicillin 18.9%, streptomycin 18.9%, tmp-smz 8.6%, ampicillin 2.8% and chloramphenicol 1.9%. Patterns of resistance to sulfa, streptomycin, chloramphenical and tetracycline have already started at the early part of 1960 decade. Although ampicillin was highly sensitive to shigella at the end of 1960 to the early part of 1970 decade, this study has disclosed high resistance to the strains. New antibiotics such as amikacin, cefazolin, dibekacin, gentamicin, and tobramycin have revealed highly sensitive to these strains, however, multiresistance for those antibiotics will be shown to be prevalent in this country within several years, where it is probably related to the unrestricted sale and use of antibiotics in man.