• Korean Journal of Fisheries and Aquatic Sciences
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• v.50 no.5
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• pp.494-499
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• 2017

This study evaluated the abundance of fecal coliforms in oysters Crassostrea gigas, sea squirts Halocynthia roretzi and sea cucumbers Apostichopus japonicus in fisheries along the coast of Korea in 2014, and investigated the prevalence of antimicrobial resistance in Escherichia coli isolated from these fishery products. The ranges of fecal coliforms found in oysters, sea squirts and sea cucumbers were <18-20, <18-330 and <18-3,300 MPN (most probable number)/100 g, respectively. Sea squirts contained the greatest range of E. coli (<20-140 MPN/100 g), followed by sea cucumbers (<20-130 MPN/100 g) and oysters (<20-20 MPN/100 g). A total of 26 strains of E. coli were isolated from 34 sea squirt, 25 sea cucumber and 13 oyster samples. Strains thus isolated were tested for their susceptibility to 22 antimicrobial agents used in Korea for medical or veterinary therapy. E. coli isolates showed the greatest resistance to ampicillin (84.6%), followed by trimethoprim (34.6%), nalidixic acid (34.6%), tetracycline (30.8%), pipemidic acid (26.9%), streptomycin (23.1%), chloramphenicol (23.1%), trimethoprim/sulfamethoxazole (23.1%), and gentamicin (15.4%). Resistance to at least one antimicrobial agent was present in 88.5% of E. coli isolates. Of the 26 isolated, six strains (23.1%) were resistant to multiple antimicrobial agents.

• Journal of Food Hygiene and Safety
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• v.37 no.2
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• pp.63-68
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• 2022

The purpose of this study is to investigate the distribution of toxin genes and antimicrobial resistance of Vibrio parahaemolyticus isolated from seafood in Gwangju. A total of 335 seafood, including 163 shellfish, 97 fish, and 36 mollusk, were tested in this study. As a result, V. parahaemolyticus was detected in 123 (36.7%) of 335 seafood. The tdh gene was not detected in all strains, while the trh gene was detected in 3 strains (2.4%). According to antimicrobial susceptibility test, 116 strains (94.3%) represent resistance to ampicillin, and 1 strain (0.8%) represents resistance to trimethoprim/sulfametoxazole. However, all strains were sensitive to 9 antimicrobial agents, including amikacin, chloramphenicol, tetracycline, and more. Therefore, the risk of V. parahaemolyticus isolated from seafood in Gwangju is considered low, but continuous monitoring of V. parahaemolyticus in seafood is required.

• Korean Journal of Veterinary Research
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• v.51 no.4
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• pp.267-275
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• 2011

Methicillin-resistant Staphylococcus (S.) aureus (MRSA) is one of the most important nosocomial pathogens worldwide and the emergence of this strain has become a major clinical problem. In this study, we investigated the prevalence of MRSA and their genetic characteristics in 69 S. aureus isolated from humans and animals. In human isolates, higher antimicrobial resistance rates were observed against penicillin (80.6%), followed by erythromycin (11.9%) and tetracycline (9.0%). All of them were susceptible to clindamycin, enrofloxacin, novobiocin, pirlimycin, trimethoprim/sulfamethoxazole and vancomycin. The resistance patterns in animal isolates were similar to those of human isolates. Two (2.9%) MRSA strains were isolated from human (n = 1) and animal (n = 1), and these isolates were confirmed as carrying the mecA gene. One isolate originating from human was resistant to 7 drugs and the other isolate derived from animal was resistant to 11 drugs. Staphylococcal cassette chromosome mec (SCCmec) variant IIIB was identified in animal isolate but SCCmec type of an isolate from human was not exactly determined. Two MRSA isolates showed unrelated PFGE pattern between them. Our results indicated although the frequency of MRSA isolates from humans and animals was low, a continuous surveillance and monitoring should be called for to prevent the contamination and spread of MRSA in the community. To our knowledge, this is the first time that SCCmec type variant IIIB was detected from animals in Korea.

• Journal of Environmental Health Sciences
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• v.21 no.2
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• pp.42-53
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• 1995

광주시 지역에서 사육하고 있는 젖소 1,614두중 유방염으로 의심되는 730분방 중에서 170분방을 검사분석하여 유방률, 균의 분리와 간이검사법과의 관계, 계절별 분리균의 분포, 항균 요법제에 대한 감수성 등을 검사하였다. 본 원인균은 730분방 중 134분방(18.4%)에서 분리되었으며 체세포 숫자는 평균 $1.620 imes 10^6pm 1.167 imes 10^6/ml$(C.V. 72.0%)이었다. CMT 반응치는 평균 $2.9pm 1.2$(C.V. 41.4%)이었으며 WT 반응치는 평균 $2.8pm 1.2$(C.V. 42.9%)이었다. RBVT와 CMT의 상관계수는 0.82(P<0.001)이었고 RBVT와 WT의 상관계수는 0.75 (P<0.001)이었으며 CMT와 WT의 상관계수는 0.93 (P<0.001)이었다. 체세포 숫자를 기준으로 하여 CMT 및 WT의 양성율을 비교하여 보면 원인균이 분리된 경우에는 체세포 숫자가 $0.49 imes 10^6$ 이하/ml의 경우에 반응치가 1+일때의 CMT는 72.4%, WT는 42.1%이었고 체세포 숫자가 $0.50 imes 10^6~1.00 imes 10^6/ml$의 경우에 반응치가 2+일 대의 CMT는 45.5%, WT는 48.8%이었으며, 체세포 숫자가 $3.01 imes 10^6$ 이상/ml의 경우에 반응치가 3+일 때의 CMT는 73.7%, WT는 92.3%이었다. 원인균의 월별 분리 빈도를 보면 8월 (17.9%)이 가장 높았고 다음은 9월(16.4%), 7월 (12.7%), 6월 (11.2%), 1월 (9.0%)의 순이었다. 원인균의 분리 빈도를 보면 Staphylococcus sp. (51.4%)가 가장 높았고 다음은 Escherichia coli(23.9%), Pseudomonas sp. (11.2%). Streptococcus sp. (6.7%)의 순이었다. 항균 요법제에 대한 감수성은 trimethoprim/sulfamethoxazole은 Streptococcus sp., Staphylococcus epidermidis, Proteus sp., Salmonella sp. 등에 높았고 gentamycin은 Streptococcus sp., Staphylococcus aureus, Enterobacteriaceae, Klebsiella sp., Proteus sp., Salmonella sp. 등에 높았으며 enrofloxacin은 일반적으로 거의 모든 균에서 감수성이 높았다.

• Biomedical Science Letters
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• v.11 no.4
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• pp.525-531
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• 2005

Staphylococcus aureus is a major cause of nosocomial infections and is one of the most commonly isolated bacterial species in the hospital and continues to be an important pathogen in both community and hospital-acquired infection. Methicillin resistant S. aureus (MRSA), which is associated with hospitals is now being isolated in the community. The purpose of this study is to investigate the carrier rate of S. aureus in the community, antibiotic resistance patterns of the organism, detection of MRSA and mecA gene in MRSA. Ninety strains $(46.4\%)$ of S. aureus were isolated from the nasal specimens of 194 elementary school students. Eighty-nine strains $(98.9\%)$ of 90 S. aureus were resistant to penicilin, 36 strains $(40.0\%)$ to erythromycin, 14 strains $(15.6\%)$ to fusidic acid, 11 strains $(12.2\%)$ to gentamycin, 9 strains $(10.0\%)$ to tobramycin, 5 strains $(5.6\%)$ to oxacillin, 4 strains $(4.4\%)$ to clindamycin, 2 strains $(2.2\%)$ to tetracycline, 1 strains $(1.1\%)$ to fosfomycin. None of $90(0\%)$ S. aureus isolates was resistant to ciprpfloxacin, trimethoprim/sulfamethoxazole, levofloxacin, linezolid, moxifloxacin, nitrofurantoin, norfloxacin, rifampicin, quinupristin/dalfopristin, teicoplanin, and vancomycin. Five strains $(5.6\%)$ of 90 S. aureus isolates were MRSA. The mecA gene was detected from five MRSA strains by PCR.

• Biomedical Science Letters
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• v.21 no.2
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• pp.84-91
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• 2015

To provide guidelines for the empirical treatment of urinary tract infections, we observed annual changes in the occurrence frequency and antimicrobial susceptibility of urinary isolates in a university hospital in the Chungbuk province, South Korea, over a period of 10 years (2004~2013). Escherichia coli (38.2%), Enterococcus faecalis (11.7%), Klebsiella pneumoniae (7.3%), Pseudomonas aeruginosa (4.3%), E. faecium (4.3%), and Staphylococcus aureus (4.1%) were commonly isolated urinary pathogens. The prevalence of E. coli, E. faecium and Streptococcus agalactiae were significantly higher in females (P < 0.001), whereas E. faecalis, P. aeruginosa and S. aureus were significantly more common in male patients (P < 0.001). E. coli mostly frequently showed resistance to ampicillin (67.94%), followed by trimethoprim/sulfamethoxazole (36.06%) and ciprofloxacin (26.84%). Over the studied time period, resistance rates of E. coli to ciprofloxacin significantly increased (20.44% to 33.55%). Moreover, extended-spectrum $\beta$-lactamase (ESBL) producing isolates also significantly increased in E. coli (4.2% to 18.3%) and K. pneumoniae (9.6% to 26.9%). In addition, the proportion of vancomycin-resistant Enterococcus facium (VRE) also increased (15.7% to 25.0%). In conclusion, over the last 10 years, the proportions of ciprofloxacin resistant E. coli and multidrug-resistant bacteria, such as ESBL and VRE have significantly increased. This trend must be strictly controlled and demonstrates the need for more updated guidelines for the treatment of urinary tract infections.

• Journal of Veterinary Clinics
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• v.21 no.2
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• pp.133-139
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• 2004

Bacterial pathogens were isolated from 36 dogs with respiratory signs, that were submitted to Veterinary Clinics in Jeju, including Veterinary Medical Teaching Hospital in Cheju National University. Of 36 isolates, 16 (44.4%) bacterial pathogens were Gram-positive and 20 (55.6%) were Gram-negative. Gram-positive bacteria identified with API Staph were 12 S. intermedius (33.3%), 2 S. aureus (5.6%), 1 S. haemolyticum (2.8%), and 1 S. xylosus (2.8%). Gram-negative organisms identified with API 20E or API NE included 8 Bordetella bronchiseptica (22.2%), 6 Escherichia coli (16.7%), 4 Pasteurella spp. (11.1%), 1 Enterobacter intermedius (2.8%), and 1 Oligella ureolytica (2.8%). Both Staphylococcus spp. isolates and Gram-negative pathogens were resistant to one or more antibiotics, including ampicillin (AM), amoxicillin/clavulanic acid (AMC), chloramphenicol (C), cefazolin (CZ), erythromycin (E), gentamicin (GM), kanamycin (K), lincomycin (L), oxacillin (OX), trimethoprim/sulfamethoxazole (SXT), and tetracycline (TE). All Staphylococcus spp. were susceptible to AMC, OX and VA, while many isolates were highly resistant to L (87.5%), E (68.8%), P (62.5%), and AM (56.3%). Antibiotic-resistant patterns of staphylococcal isolates were shown ranges from single to 9-resistant patterns. Resistant rates to antibiotics of Gram-negative bacteria were usually higher than those of Staphylococcus spp. in this study. Most Gram-negative bacteria were highly resistant to L (90.0%), AM (85.0%), E (85.0%), P (85.0%), OX (80.0%), and CZ (75.0%). B. bronchiseptica isolates showed 5 to 8 antibiotics-resistant patterns and Pasteurella spp., 2 to 8-resistant patterns. In particular, all 6 E. coli isolates were resistant to more than 9 different kinds of antibiotics, including one strain resistant to all antibiotics tested.

• Korean Journal of Veterinary Research
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• v.19 no.2
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• pp.121-126
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• 1979

대장균 설사중에 걸린 어린 돼지, 송아지, 어린 양에서 분리한 대장균 126주의 항생제와 화학요법제(15종)에 대한 감수성을 disc diffusion technique로 조사한 성적은 다음과 같다. 1. 어린 돼지에서 분리한 62주의 대장균은 gentamicin(GM)에 100%, colistin(CL)에 96.8%, kanamycin(KM)에 93.5%, neomycin(NM)에는 91.9%가 감수성을 가지고 있었으나 ampicillin(AM), erythromycin(EM), lincomycin (LM), novobiocin (NB), penicillin (PC), streptomycin(SM), tetracycline(TC), sulfaisodimidin(SU)에는 내성을 가지고 있었다. chloramphenicol(CP), sulfamethoxazole-trimethoprim(SXT), cephalosporin(CE)에는 각각 75.8%, 64.5%, 50%가 감수성이 있었다. 2. 송아지에서 분리한 32주의 대장균은 GM에 100%, CL에는 87.5%, SXT에는 66.7%가 감수성이 있었으나 CP와 KM에는 각각 40.6%, SU에는 56.2% NM에는 62.5%, SM에는 87.5%가 내성을 가지고 있었다. EM, LM, NB, PC에는 전혀 감수성이 없었으며 AM, SM, TC에도 고도의 내성을 가지고 있었다. 3. 어린 양에서 분리한 32주의 대장균은 GM과CL에 100%, CP에 96.9%, KM과 NM에 90.6%가 감수성이 있었다. SM과 SU에도 71.9%나 감수성이 있었으나 CM, EM, LM, PC, TC에는 대부분 내성을 가지고 있었다. AM에는 21.9%가 감수성이 있었다. 4. 2종류 이상의 약제에 내성을 가진 대장균의 AM, CE, CP, CL, GM, KM, NM. SM, TC, SU등 10종의 약제에 대한 multiple drug resistance pattern(MDRP)을 조사한 바 돼지 유래 약제내성 대장균의 MDRP는 18가지였으며 이중 가장 빈도가 높은 것은 AM, CE, SM, TC, SU 내성형으로 전체의 24.2%나 되었다. 송아지 유래 약제내성 대장균의 MDRP는 17가지였으며, AM, CE, CP, KM, NM, SM, TC, SU 내성형이 28.1%로 가장 빈도가 높았다. 반면에 어린 양에서 분리한 대장균의 MDRP는 9가지였으며 AM, CE, SU의 3약제 내성형이 40.6%로 가장 많았다.

• Childhood Kidney Diseases
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• v.21 no.2
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• pp.121-127
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• 2017

Purpose: The aim of this study was to determine the prevalence of antibiotic susceptibility and resistance of Escherichia coli in urinary tract infections (UTIs) in children. Methods: We retrospectively reviewed the clinical records of 212 inpatients aged 18 years or younger with UTIs treated at the Pediatric Department of Dongguk University Gyeongju Hospital between January 2008 and December 2016. For comparison, patients were divided into three groups according to age as follows: group 1, ${\leq}1$ month; group 2, >1 month to ${\leq}12$ months; and group 3, ${\geq}13$ months. The antibiotic resistance rates from January 2008 to December 2012 (study period 1) and from January 2013 to December 2016 (study period 2) were analyzed statistically by group. Results: As the patient age increased, the antibiotic resistance rate to ampicillin (P=0.013), levofloxacin (P=0.050), piperacillin/tazobactam (TZP) (P<0.001), and trimethoprim/sulfamethoxazole (P=0.002) increased. The frequency of extended spectrum beta-lactamase producing E. coli showed a significant difference from 5 cases (4.6%) in study period 1 and 16 cases (15.8%) in study period 2 (P=0.007). The antibiotic resistance rate of E. coli was compared between the two time periods and we found that the antibiotic resistance rate to cefotaxime was significantly increased from 5.4% to 16.8% (P=0.008) and that to TZP was significantly decreased from 40.5% to 7.9% (P<0.001). Conclusion: Over the past 9 years, the resistance rate to cefotaxime has increased but the resistance rate to TZP has decreased. Thus, it is important to continue to investigate the antibiotic resistance rates of bacteria in the community.

• Clinical and Experimental Pediatrics
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• v.54 no.2
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• pp.79-85
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• 2011

Purpose: We studied the differences in the antibiotic susceptibilities of the microorganisms that causeing urinary tract infections (UTI) in children to obtain useful information on appropriate drug selection for childhood UTI. Methods: We retrospectively analyzed the antibiotic susceptibilities of 429 microorganisms isolated from 900 patients diagnosed with UTI in the Department of Pediatrics, Chungbuk National University Hospital, from 2003 to 2008. Results: The most common causative microorganisms for UTI were Escherichia coli (81.4%), Klebsiella pneumoniae (8.4%), Enterobacter spp. (1.7%), and Proteus spp. (0.4%). E. coli showed relatively high susceptibility as compared to imipenem (100%), amikacin (97.7%), aztreonam (97.9%), cefepime (97.7%), and ceftriaxone (97.1%), while it showed relatively low susceptibility to gentamicin (GM) (79.0%), trimethoprim/sulfamethoxazole (TMP/SMX) (68.7%), ampicillin/sulbactam (33.0%), and ampicillin (AMP) (28.6%). There were no significant differences in the image findings for causative microorganisms. Conclusion: Gram-negative organisms showed high susceptibility to amikacin and third-generation cephalosporins, and low susceptibility to AMP, GM, and TMP/SMX. Therefore, the use of AMP or TMP/SMX as the first choice in empirical and prophylactic treatment of childhood UTI in Korea should be reconsidered and investigated further.