• Journal of Environmental Health Sciences
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• v.45 no.3
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• pp.222-230
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• 2019

Objectives: This study aims to evaluate water quality in terms of microorganisms and identify the antibiotic resistance of Enterococci isolated from the recycling water in floor fountains at three parks and one reservoir in the Gwangju area. Methods: Water samples were analyzed for Enterococci using membrane Enterococcus indoxyl ${\beta}$ d glucoside agar (mEI) as described in USEPA Method 1600. The vancomycin-resistant Enterococci with VanA and VanB were identified by PCR. An examination of the antibiotic resistance of isolates against 14 antibiotics was performed by the disk diffusion method. Results: The drinking water quality criterion was exceeded for total colony counts in 68% of all recycling water samples. The average concentration of total califorms and fecal coliforms was 139,325 and 413 CFU/100 mL, respectively. VanA and VanB were not detected from the isolates. We found the antibiotic resistant Enterococci strains to be E. faecalis, E. faecium, E. durans, E. mundtii, E. hirae, and E. thailandicus. The isolates were resistant to Rifampin (50%), Erythromycin (25.8%), Tetracycline (10.2%), Nitrofurantoin (8.1%), Minocycline (3.1%), Erythromycin (1.2%), Penicillin (0.7%), Norfloxacin (0.5%), and Teicoplanin (0.5%) among the 14 antibiotics tested. Antibiotic resistance tests for Enterococci from the recycling water of floor fountains resulted in 30.2% showing resistance to two or more antibiotics. Conclusions: These results showed that the multi-antibiotic resistance of Enterococci, E. coli, and others should be investigated continuously in each environment field.

• The Journal of the Korean Society for Microbiology
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• v.22 no.3
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• pp.283-294
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• 1987

One hundred and fifty-seven strains of staphylococci isolated from various clinical specimens and 80 of Gram-negative bacilli from urine of patients with urological diseases were tested for resistance to antimicrobial drugs by microdilution broth method. Among staphylococci, 50 to 89% of the strains were resistant to gentamicin(Gm), kanamycin(Km), erythromycin(Em), nalidixic acid(Na), and tetracycline. Ninety per cent MIC was lowest in ciprofloxacin(Cp), followed by vancomycin(Vc), trimethoprim(Tp), enoxacin(Ex), and norfloxacin(Nf) with the values of two ${\mu}g/ml$ or lower. Twenty-seven strains were resistant to methicillin(MR), with 24 strains of Staphylococcus aureus and 3 of S. epidermidis. All strains of MR S. aureus were resistant to oxacillin, rifampin(Rf), Gm, Km, Em, Na, and Tc, and no strain was resistant to Vc and Tp. Almost all staphylococci isolated from urine were S. epidermidis and sensitive to most drugs tested without MR strain. Among Gram-negative bacilli from urine, Escherichia coli(43 strains) was most frequently isolated, and followed by Klebsiella spp.(11), Proteus spp.(10), Serratia spp.(10), and Pseudomonas aeruginosa(6) in the decreasing order. The majority of E. coli and Serratia spp. were resistant to chloramphenicol(Cm), Tc, streptomycin, sulfisomidine(Su), ampicillin(Ap), Km, and carbenicillin(Cb), and 50 and 90% MICs of these drugs were also high. In Klebsiella spp., 54% or more were resistant to Cm, Su, Ap, cephalothin, and Cb. Proteus spp. were susceptible to most drugs tested, but Pseudomonas were resistant to nearly all drugs tested except Rf, amikacin, and moxalactam(Mx). All Gram-negative bacilli tested were found to be susceptible to Mx. New quinolone carboxylic acid compounds, such as Nf, Ex, and Cp showed very high antimicrobial activities against the majority of organisms tested except Pseudomonas, and 50 and 90% MICs of Nf and Ex were always equal or 2 to 4 times higher than Cp. Organisms multiply resistant to drugs were noted in almost all isolates tested. Twenty-seven strains of staphylococci were multiply resistant to 11 or more drugs, and 6 of Klebsiella spp. to 8 to 11 drugs. The most frequent multiplicity of durg resistance were 7 and 8, 12, and 13 in E. coli, Serratia spp., and Pseudomonas, respectively. No strain was resistant to more than 5 drugs in Proteus spp..

• 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.

• Korean Journal of Veterinary Research
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• v.29 no.3
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• pp.315-324
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• 1989

In order to establish the extent of Streptococcal arthritis piglets, isolation of Streptococci from arthritic lesions of 34 piglets were undertaken from November 1987 to October 1988 in Korea. Also determined were isolation frequency of Streptococci in nasal cavity of 250 healthy sows and antibiotic susceptibilities of the isolates. Streptococci were isolated from 52.9% of 34 arthritic piglets and 20 strains isolated belonged to 4 S suis type I, 8 S suis type II, 2 Lancefield group C and 6 group E. From 28.8% of 250 healthy sows, 72 strains of Streptococci were isolated and these consisted of 9 S suis type I, 51 S suis type II and 12 group C. Streptococcal arthritis seemed to occur prominently in piglets aged 2 to 4 weeks and in male than female. No significant difference were recognized in tarsal and carpal joints as affecting site. All of 92 isolates were sensitive to ampicillin and penicillin, and all strains of S suis type I and group E Streptococcus were also sensitive to chloramphenicol and cephalothin. To cephalothin all strains of group C Streptococcus were sensitive. The 1. 7 to 100% of 92 isolates were resistant with different prevalence to colistin, erythromycin, kanamycin, tetracycline, gentamicin, chloramphenicol and cephalothin. The 92.5% of these resistant Streptococci were multiply drug-resistant strains. The drug resistant patterns most frequently encountered were Tc Cl Em Km Gm(16.3%) in quintuple pattern, Tc Cl Em Km(16.3%) in quadruple pattern, Tc Cl Em(10.9%) in triple pattern and Cl Em(14.1%) in double pattern.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.41 no.6
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• pp.435-439
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• 2008

The antimicrobial resistance of 160 strains of Enterococcus faecalis and 173 strains of E. faecium to 12 antimicrobial agents was investigated. The test strains were isolated from 126 wild seawater and farmed fish, including olive flounder (Paralichthys olivaceus), black rock fish (Sebastes schlegeli), red sea bream (Pagrus major), and sea bass (Lateolabrax japonicus), in 2005 and 2006. Overall, 91.9% of the E. faecalis isolates and 88.4% of the E. faecium isolates showed antimicrobial resistance to at least one antimicrobial agent. The pattern of antimicrobial resistance of the isolates differed little according to the species of fish. The percentage of E. faecalis and E. faecium with specific antimicrobial resistance differed according to the sample source. For the isolates from farmed fish samples, 66.7% of E. faecalis were tetracycline resistant and 54.5% of E. faecium were erythromycin resistant. By contrast, in the wild fish seawater samples, 92.0% of E. faecalis were rifampin resistant and 88.5% of E. faecium were tetracycline resistant.

• Korean Journal of Veterinary Research
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• v.45 no.2
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• pp.163-168
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• 2005

This study was carried out to investigate the antibiotic resistance pattern of Enterococcus spp. and Staphylococcus aureus (S. aureus) isolated from chicken feces. All isolates showed high resistance to erythromycin (E) and tetracycline (TE). Of the 63 Enterococcus faecalis (E. faecalis) isolates, 73.0% were resistant to E and 98.4% to TE. Of the 44 Enterococcus faecium (E. faecium) isolates, 50.0% were resistant to E and 95.5% to TE. Of the 52 S. aureus isolates, 57.6% were resistant to E and 96.2% to TE. The prevalence of two and three drugs resistance pattern were 28.6% and 17.5% of E. faecalis, 40.9% and 25.0% of E. faecium and 38.5% and 23.1% of S. aureus, respectively. The multiple resistance pattern to six drugs was observed in 1 E. faecalis isolates, and five drugs resistance pattern were seen in 1 E. faecalis, 1 E. faecium and 1 S. aureus isolates. The prevalence of resistant organisms in Korea probably reflects lack of proper antibiotic policy resulting in prolonged and indiscriminate use of antimicrobial agents.

• Korean Journal of Veterinary Service
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• v.42 no.2
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• pp.53-60
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• 2019

This study was performed to investigate antimicrobial resistance in bacterial isolates obtained from companion dogs in veterinary hospitals and an animal shelter in Incheon. Drug resistance was examined respectively with the isolates of Escherichia coli, Enterococcus faecalis, and Staphylococcus pseudintermedius. The prevalence of drug resistance was calculated for each bacterial species towards 163 E. coli isolates, 156 E. faecalis isolates, and 86 S. pseudintermedius isolates by using selected antimicrobials. E. coli isolates were highly resistant to ampicillin, ciprofloxacin and tetracycline (47.9%, 28.2% and 28.2%, respectively). E. faecalis isolates were highly resistant to quinupristin-dalfopristin, tetracycline, kanamycin, rifampicin (69.8%, 66.0%, 53.8% and 51.9%, respectively). Higher levels of resistance were detected for ampicillin, penicillin, tetracycline, erythromycin, trimethoprim/sulfamethoxazole, telithromycin in S. pseudintermedius isolates (83.7%~52.6%, respectively). Occurrence of methicillin-resistant S. pseudintermedius (MRSP) was confirmed by oxacillin disc diffusion method, resulted in 23.3% occurrence among the S. pseudintermedius isolates (20/86 strains). The occurrence ratio of multidrug-resistance in the isolates of E. coli, E. faecalis, and S. pseudintermedius was 34.5%, 56.9%, and 67.9%, respectively. In this study, higher levels of antimicrobial drug resistance were observed in bacterial isolates obtained from dogs in Incheon. A regular monitoring and surveillance program should be implemented to prevent the emergence and spread of the drug-resistant bacteria carried in companion dogs.

• Food Science of Animal Resources
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• v.37 no.2
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• pp.175-180
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• 2017

The objectives of this study were: i) to detect the presence of Staphylococcus aureus and methicillin-resistant S. aureus (MRSA) in raw milk, cheese, beef minced meat, and chicken meat samples; ii) to evaluate the antimicrobial susceptibility of the isolates; and iii) to determine clonal relation among the isolates by using pulsed-field gel electrophoresis (PFGE) method. Therefore, a total of 160 food samples were randomly collected between August 2014 and May 2015 in Hatay province, located in the southern Turkey. Twenty (12.5%) of the samples were found to be contaminated with S. aureus. A total of 40 isolates from the 20 positive samples were confirmed to be S. aureus by multiplex PCR based on 16S rRNA and nuc gene. The mec A gene was not detected in any of the S. aureus strains. In the present study, 39 out of 40 (97.5%) isolates were found to be resistant to one or more antibiotics. All of isolates were susceptible to gentamicin, oxacillin, and vancomycin. The highest resistance rate was detected in penicillin (95%) and ampicillin (92.5%), followed by tetracycline (30%), erythromycin (20%), ciprofloxacin (12.5%). Nine major patterns were determined by PFGE. In 6 of these patterns, thirty-six strains (90%) had identical PFGE profiles.

• Restorative Dentistry and Endodontics
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• v.29 no.5
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• pp.462-469
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• 2004

The aim of this study was to investigate the susceptibility of mutans streptococci (S. mutans and S. sobrinus) and Streptococcus anginosus, for seven antibiotics, penicillin G, amoxicillin, ciprofloxacin, cefuroxime, erythromycin, bacitracin, and vancomycin. The minimum inhibitory concentration (MIC) of seven antibiotics against 3 species (type strains) of mutans streptococci and S. anginosus, 10 strains (wild type) of S. mutans, 7 strains (wild type) of S. sobrinus, and 11 strains (wild type) of S. anginosus, were measured by broth dilution method. All of the type strains of mutans streptococci and S. anginosus had the same susceptibility for penicillin G, amoxicillin, cefuroxime and bacitracin. Type strain of S. anginosus was sensitive in ciprofloxacin, but those of mutans streptococci were not. All of the clinical isolates of mutans streptococci and S. anginosus had the same susceptibility for the seven antibiotics. Our data reveal that mutans streptococci and S. anginosus have similar antibiotic-resistant character. In addition. these results may offer the basic data to verify the antibiotic-resistant mechanism of mutans streptococci and S. anginosus.

• Korean Journal of Veterinary Research
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• v.41 no.4
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• pp.511-521
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• 2001

Microorganisms were isolated and identified from bovine 296 quarters which showed positive reaction by California Mastitis Test (CMT) in 40 farms of Jeju from September 1999 to June 2000. The organisms associated with the mastitis of bovine were 11 different bacterial species in this study. Which of them, Staphylococcus aureus was the most predominant species as 152 (51.4%) isolates. Other identified species included 49 (16.5%) coliform, 47 (15.8%) Streptococcus dysgalactiae, 15 (5.1%) Bacillus spp., 8 (2.7%) Staphylococcus epidermidis, 6 (2.1%) Streptococcus agalactiae, 5 (1.7%) Enterococcus faecalis, 5 (1.7%) Corynebacterium spp., 3 (1.0%) Streptococcus uberis, 1 (0.3%) Pseudomonas aeruginosa and 1 (0.3%) Pasteurella haemolytica. Almost of all the islolated beacterial species showed high sensitivity against kanamycin (98.6%), cephalothin (98.0%), streptomycin (94.9%), gentamicin (94.6%), ampicillin (92.2%) and polymyxin B (90.2%). On the contrary, they showed resistance against penicillin (47.0%), tetracycline (37.2%), cefazolin (26.0%), bacitracin (22.6%) and erythromycin (19.9%). Eighty-one isolates were not resistant to any antibiotics and 215 drug resistant isolates showed 89 different drug resistance patterns from single to nine multiple antibiotics resistance patterns.