• Journal of Microbiology and Biotechnology
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• v.27 no.11
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• pp.2052-2059
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• 2017

The emergence and dissemination of Salmonella genomic island 1 (SGI1) are strongly associated with the occurrence of multidrug-resistant (MDR) enterobacteria in humans and animals. Diverse SGI1s have been reported among Salmonella enterica and Proteus mirabilis in several countries. We aimed to characterize SGI1 in P. mirabilis isolates from humans and chickens in Chungcheong Province, Korea. A total of 44 P. mirabilis isolates were recovered from humans (n = 20) and chickens (n = 24). Antimicrobial susceptibility was determined by disk diffusion assay. To detect and characterize SGI1s, PCR amplification and PCR mapping experiments were performed. Repetitive extragenic palindromic-PCR (REP-PCR) was performed to assess the clonality of the isolates. The four P. mirabilis strains (16.7%) from chicken harbored a SGI1, whereas none of the isolates from clinical specimens contained SGI1. The SGI1s detected in our study were all confirmed as SGI1-PmABB harboring aminoglycoside-resistant genes (aacCA5 and aadA7). In P. mirabilis isolates, the presence of SGI1-PmABB was significantly correlated with high resistance rates of the isolates to antimicrobial agents, such as gentamicin, streptomycin, and spectinomycin. Moreover, the four SGI1-bearing isolates showed the same REP-PCR patterns and that suggested both horizontal and clonal spread of the isolates. This study is the first attempt to determine SGI1s in P. mirabilis isolates in Korea. We confirmed that P. mirabilis isolates carrying SGI1-PmABB were distributed at poultry farms in Korea. The present study emphasizes the need for continuous monitoring of SGI1s to prevent spreading of the MDR genomic islands among P. mirabilis isolates from humans and animals.

• Korean Journal of Veterinary Research
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• v.47 no.4
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• pp.395-398
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• 2007

A total of 114 Salmonella spp. (17.90%) were isolated from 637 fecal swab samples collected in October 2005 and they were from 25 (78.13%) of 32 farms investigated nation-widely in Korea. Salmonella spp. from age group of 30-, 60-, 90-, 120-day olds were 17.61%, 16.98%, 15.72%, and 21.25%, respectively. Nine serovars of Salmonella spp. were identified. The predominant serovars of isolates were S. Typhimurium (including var Copenhagen), S. Agona, S. Derby, and S. Heidelberg by turns. Almost isolates belonged to serogroup B (69.30%). All isolates were resistant to penicillin G and oxytetracycline, and this was considered due to be used as feed additive through the most of pig farms for decades. And also, frequent resistance observed for ampicillin, sulfamethoxazole-trimethoprim, and lincomycin-spectinomycin, which are commonly used in veterinary medicine for decades, indicates an urgent need to utilize these antimicrobials more prudently if their benefits are to be preserved.

• Korean Journal of Microbiology
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• v.42 no.4
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• pp.286-293
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• 2006

Three hundred thirty two bacterial colonies which were able to degrade crude oil were isolated from soil samples that were contaminated with oil in Daejon area. Among them, one bacterial strain was selected for this study based on its low surface tension ability, and this selected bacterial strain was identified as Pseudomonas sp. G314 through physiological-biochemical tests and analysis of its 16S rRNA sequence. Pseudomonas sp. G314 showed a high resistance to antibiotics such as ampicillin, chloramphenicol, spectinomycin, and streptomycin, and heavy metals such as Li, Cr, and Mn. It was found that the optimal pH and temperature for biosurfactant production of Pseudomonas sp. G314 were pH 7.0 and $30^{\circ}C$, respectively. After seven hours of inoculated, the biosurfactant activity reached the maximum, and surface tension of the culture broth was decreased from 72 to 25 dyne/cm. The crude biosurfactant was obtained from the culture broth by acid precipitation, followed by solvent extraction, evaporation and then freeze drying. The CMC (critical micelle concentration) value of the crude biosurfactant was 20 mg/L.

• Journal of Veterinary Clinics
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• v.24 no.1
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• pp.19-25
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• 2007

This study carried out to investigate the genital tract bacterial flora of Thoroughbred mare in Jeju province during March and July, 2006. The specimens were collected from vaginal ucosa and clitorial fossa using a culture swab (BBL, USA) from 100 Thoroughbred mares. Colonies were selected blood and MacConkey agar plate, and identified as standard biochemical properties using Biolog system (Thermo, USA). In this study, 470 gram-negative strains were isolated more frequently than 249 gram-positive strains. We were Isolated Escherichia coli (19.8%), Proteus mirabillis (14.9%), Enterobacter nimipressuralis (7.4%), Enterobacter mobilis (4.7%), Aeromonas encheleia (4.3%), Pseudomonas aeroginosa (3.0%), Staphylococcus aureus (14.9%), Staphylococcus epidermidis (11.2%), Coagulasenegative Staphylococcus spp. (10.0%), Enterococcus faecalis (9.2%), Enterococcus faecium (8.0%), Actinomyces viscosus (7.2%), Micoroccus diversus(6.8%), Streptococcus dysgalactiae subsp. equisimilis(5.2%), Streptococcus equi subsp. zooepidemicus (3.2%), Other non-beta hemolytic Streptococcus spp. (2.0%) and many others from vaginal mucosa and clitorial fossa in Thoroughbred mares. No significant bacteria (Taylorella equigenitalis and Klebsiella pneumonia) were isolated from the mare genital tract. In antimicrobial agents susceptibility test, it shows a high sensibility in the antibiotics of the most which excepts the streptomycin and neomycinm, kanamycin, spectinomycin, compound sulfonamides. Especially, Staphylococcus epidermidis, Enterococcus spp. and Streptococcus spp. were visible a high sensibility in the all antibiotics. However, Staphylococcus aureus, Pseudomonas aeruginosa, Proteus spp. and E. coli were showed a high antibiotic resistance patterns. These results may provide the basic information to establish strategies for the treatment and prevention of reproductive disease in Thoroughbred mares in Korea.

• Microbiology and Biotechnology Letters
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• v.48 no.2
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• pp.185-192
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• 2020

The global carbon storage regulator (Csr) system is conserved in bacteria and functions as a regulator in the exponential and stationary phases of growth in batch culture. The Csr system plays a role in the central carbon metabolism, virulence, motility, resistance to oxidative stress, and biofilm formation. Although the Csr was extensively studied in Gram negative bacteria, it has been reported only in the control of motility in Bacillus subtilis among Gram positive bacteria. The goal of this study was to explore the role of the csrA gene of Bacillus licheniformis M2-7 on motility and the bacterial ability to use hydrocarbons as carbon source. We deleted the csrA gene of B. licheniformis M2-7 using the plasmid pCsr-L, harboring the spectinomycin cassette obtained from the plasmid pHP45-omega2. Mutants were grown on culture medium supplemented with 2% glucose or 0.1% gasoline and motility was assessed by electron microscopy. We observed that CsrA negatively regulates motility by controlling the expression of the hag gene and the synthesis of flagellin. Notably, we showed the ability of B. licheniformis to use gasoline as a unique carbon source. Our results demonstrated that CsrA is an indispensable regulator for the growth of B. licheniformis M2-7 on gasoline.

• Journal of Life Science
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• v.22 no.8
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• pp.1114-1119
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• 2012

Bacteria are frequently contaminated during the collection and processing procedures of boar semen. Of the contaminants, Stenotrophomonas (S.) maltophilia is a Gram-negative bacterium that is widely distributed in a variety of habitats. Although PCR assays have been developed for the detection of S. maltophilia, they cross-react with some species of Xanthomonas. In this study, we designed a primer set for the detection of S. maltophilia in order to target the chiA (GenBank accession no. NC_010943) gene. The specific PCR products were amplified from S. maltophilia only, not from other tested strains that are frequently found in semen. The detection limit of the PCR was $1.5{\times}10^3$ CFU/ml with pure-cultured S. maltophilia and $1.5{\times}10^4$ CFU/ml with S. maltophilia spiked in semen. Twenty-six (5.9%) S. maltophilia were isolated from 440 semen samples. The PCR results exhibited 98.9% agreement with a comparison of S. maltophilia isolation. Also, the sensitivity and specificity of the PCR were 100% and 98.7%, respectively. In the antimicrobial susceptibility test, S. maltophilia isolates were highly susceptible to enrofloxacin and florfenicol, while the majority of them were resistant to amoxicillin/clavulanic acid, apramycin, ceftiofur, penicillin, and spectinomycin. These results indicated that the PCR using the chiA gene was proven to be reliable and effective for the detection of S. maltophilia with high levels of sensitivity and specificity.

• Korean Journal of Food Science and Technology
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• v.43 no.1
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• pp.1-5
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• 2011

It is possible that veterinary medicines remain in livestock food products, according to the use of many and various veterinary medicines to protect against disease when livestock animals are breed in limited space. Concentrated and continuous monitoring of residues is needed due to increases in resistance to antibiotics and side effects by eating livestock food products. We developed an analysis method for detecting streptomycin, dihydrostreptomycin, neomycin, gentamicin and spectinomycin in meat using LC/MS/MS and measured sensitivity, precision, accuracy, linearity and recovery according to CODEX guidelines to acquire confidence in the analysis method. Based on the results, we acquired good sensitivity compared to the maximum residue limit (MRL) as limits of detection (LOD) were 0.002-0.016 mg/kg and limits of quantification (LOQ) were 0.006-0.050 mg/kg. The analysis method satisfied the CODEX guidelines. The linearity ($r^2$) values of aminoglycoside antibiotics were 0.9936-0.9980, recoveries were 60-110% and relative standard deviations (RSD) were within 15%. As a result of monitoring for residues in a total 250 samples of livestock foods such as pork, chicken, and beef by the confirmed method, dihydrostreptomycin and gentamicin were detected in 5 pork samples. The residues of these antibiotics were within the MRLs. Thus, the detection ratio was 2% as 5 samples were identified from 250 samples.

• Korean Journal of Soil Science and Fertilizer
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• v.29 no.1
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• pp.60-66
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• 1996

Bradyrhizobium japonicum with different colony morphology populated in five Yeongnam soils of Korea was examined for intrinsic antibiotic resistance to eight antibiotics, serological property by immunoblot and immunodiffusion, and protein profile differentiation by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Colony morphological distribution of one hundred and twenty B. japonicum isolates was 47% for "dry". 41% for "wet", and 12% for "dry/wet" type. The total isolates showed such a strong correlation between the morphology and antibiotic resistance. Colony morphology, which though was dominantly consisted of the same type within a serogroup, wasn't absolutely linked to serological property of B. japonicum. Based on these data, colony morphology was too simple to identify variations with B. japonicum isolates : antibiotic resistance such complicated compared with serological analyses.

• Korean Journal of Veterinary Service
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• v.34 no.1
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• pp.45-54
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• 2011

This study was conducted to investigate the distribution of Salmonella spp. from pigs and cattle in slaughterhouse, the antimicrobial resistance pattern and the prevalence of resistance genes of isolates. A total of 640 fecal samples from pigs and cattle in slaughterhouse were collected for isolation of Salmonella spp.. Isolation rate was revealed as 15% in pigs and 1.6% in cattle. As result of serotyping, group B (56.6%) were identified as most common in pigs and cattle isolates, in order of group C (24.5%) and group E (15.1%). S. Typhimurium (50.9%) was most common serotype. The major serotypes were in order of S. Rissen and S. London (11.3%) and S. Riggil (7.6%). In antimicrobial test, all isolates were demonstrates susceptibility to nitrofurantoin. But isolates were revealed resistance other antibiotics in order of tetracycline (64.6%), streptomycin (68.3%), ampicillin and amoxicillin (56.3%) and spectinomycin (47.9%). With polymerase chain reaction, antimicrobial resistance gene strA (75.0%) and aadA1 (3.1%) were detected in streptomycin resistance isolates and tetA (94.3%) and tetB (11.3%) gene were detected in tetracycline resistant isolates, but tetG was not detected. Class 1 integron gene was detected in all Salmonella isolates.

• Journal of Preventive Medicine and Public Health
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• v.16 no.1
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• pp.41-50
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• 1983

The incidence of sexually transmitted disease, especially gonorrhoea has risen despite the progress in its diagnosis and treatment. For the effective control programs of sexually transmitted disease, it should be required socio-medical approaches. A study on gonorrhoea and penicillinase-producing Neisseria gonorrhoeae(PPNG) was conducted in Jeonju and Kunsan area from March, 1982 through August, 1982. The 221 entertrainers were studied in order to determine the prevalences of gonorhoea and PPNG. Socio-demographic informations of the entertainers were obtained by interviewing them. Gonococci were cultured on Thayer-Martin enrichment media for isolation, and PPNG was confirmed using beta-lactamase reagent ($PADAC^{tm}$ Beta-Lactamase Test Strips, Galbiochem-Behring). The results of the study are summarized as follows; 1. The average age of the entertainers studied was $26.1{\pm}4.7$ years. 2. The average years of working in entertaining business was $2.4{\pm}1.4$ years, and the average income per month was $239,592{\pm}90,480$ won. On the education level, 70.6% of the entertainers were middle or high school graduates 3. 47.5% of the entertainers were using contraceptives. 90.5% have experienced artificial abortion. 4. 37(16.7%) out of 221 entertainers were revealed to gonorrhoea, and 13 (35.1%) of gonorrhoea patients were by PPNG. 5. The prevalence rates of gonorrhoea and the proportion of PPNG by age were not significant statistically. Meanwhile, the colelations between the rates of gonorrhoea and education, frequency of love-making with customers and type of sexual partner were highly significant statistically. 6. 37 strains of gonococci isolated were almostly resistant to several antimicrobial agents, especially amikacin, clindamycin and chloramphenicol. Furthermore PPNG strains were completely resistant to not only above drugs but also penicillin.