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

• Korean Journal of Veterinary Service
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• v.24 no.1
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• pp.51-68
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• 2001

The result of studying the epidemiological characteristics of Salmonella strains which have been isolated from the domestic animals in Gyeongbuk province from February 1998 to August 2000 were summarized as follows. The isolation rates of Salmonella strains were 2.0% from cattle feces, 6.3% from cattle lymph node, 9.5% from pig feces, and 25.1% from pig lymph node. In poultry, the isolation rates were 30.3%. The isolates of Salmonella showed positive reaction for MUCAP test, methyl red test, but showed negative reaction for urea test, indole test, Voges Proskauer test. On TSI agar, the isolates showed acid butt, alkaline slant. Also, the isolates were identified as Salmonella strain by API 20E kit. Non H$_2$S Production Salmonella strains isolated from poultry were identified as S gallinarum. As a result of serotyping, B group were the most common in cattle and pig, Dl in chickens. 21 serovars were found. the common serovar from the domestic animals was S typhimurium, S derby, S agona, S schwarzenground, S enteritidis and S gallinarum. The most commonly encountered serovars in cattle were S agona and S typhirimurium in pig, S gallinarum in chicken. As a result of antimicrobial susceptibility test, all Salmonella isolates were susceptible to amikacin, ciprofloxacin, norfloxacin; cefotaxime and polumcin B. The resistance rates to tetracycline and streptomycin was 58% and 56%, respectively. 69.3% of all isolates were resistant to more than one antimicrobial agent. Out of the resistant isolates, the isolates resistant to streptomycin and tetracycline was 36%. There were 24 strains of multiresistant isolates resistant to more than 5 antimicrobial agents. S typhimurium were resistant to all antimicrobial agents, also had a lot of multiresistant strains. Therefore, S typhimurium was considered as a major agent of antimicrobial resistance.

• Food Science of Animal Resources
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• v.33 no.4
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• pp.481-486
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• 2013

This study evaluates the effects of fat contents on the thermal resistance, antibiotic sensitivity, and Caco-2 cell invasion of Listeria monocytogenes. Ten strain mixture of L. monocytogenes in milk (0, 1, and 4% fat) and pork sausage patties (10, 20, and 30% fat) were exposed to $63^{\circ}C$. To evaluate effects of fat on the antibiotic sensitivity of L. monocytogenes, the L. monocytogenes strains NCCP10811 (most antibiotic resistant to streptomycin) and NCCP10943 (most antibiotic sensitive to streptomycin) were exposed to different fat contents in milk and pork sausage patties, and L. monocytogenes from the foods were used for antibiotic sensitivity assays. The most invasive L. monocytogenes strains (NCCP10943) was exposed to different fat contents in milk or pork sausage patties, and L. monocytogenes from the foods were used for the Caco-2 cell invasion assays. The reductions of L. monocytogenes populations were not generally influenced by fat contents. The L. monocytogenes subjected to milk fat had increased sensitivities (p<0.05) due to some antibiotics. In addition, Caco-2 cell invasion efficiency of L. monocytogenes NCCP10943 increased (p<0.05) as fat contents increased. These results indicated that higher fat contents may be related to L. monocytogenes invasions and heat resistances in pork sausage patties, but the relationship between fat and antibiotic sensitivity varied according to antibiotics, strains, and fat contents.

• Food Science of Animal Resources
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• v.36 no.3
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• pp.352-358
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• 2016

The aim of this study was to determine the prevalence of enterococci in cheese samples and to characterize their antimicrobial resistance profiles as well as the associated resistance genes. A total of 139 enterococci were isolated from 99 cheese samples, the isolates were identified as E. faecalis (61.2%), E. faecium (15.1%), E. gallinarum (12.9%), E. durans (5.0%), E. casseliflavis (2.9%) and E. avium (2.9%). The most frequent antimicrobial resistance observed in enterococci isolates was to lincomycin (88.5%), followed by kanamycin (84.2%), gentamycin (low level, 51.1%), rifampin (46.8%) and tetracycline (33.8%). Among the isolates, the frequencies of high level gentamycin and streptomycin resistant enterococci strains were 2.2% and 5.8%, respectively. Apart from the mentioned antibiotics, low levels of resistance to ciprofloxacin, erythromycin and chloramphenicol were found. Moreover no resistance was observed against penicillin and ampicillin. The antimicrobial resistance genes including tetM, tetL, ermB, cat, aph(3’)-IIIa, ant(6)-Ia and aac(6’)-Ieaph(2”)-Ia were found in enterococci from Turkish cheese samples. In the current study, we provided data for antibiotic resistance and the occurrence of resistance genes among enterococci. Regulatory and quality control programs for milk and other dairy products from farms to retail outlets has to be established and strengthened to monitor trends in antimicrobial resistance among emerging food borne pathogens in Turkey.

• Korean Journal of Veterinary Research
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• v.54 no.3
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• pp.131-137
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• 2014

The purpose of present study was to investigate the antimicrobial resistance in Escherichia coli isolated from healthy animals in all provinces of the Republic of Korea. A total of 2,085 E. coli strains isolated from 11,336 fecal samples of healthy animals during 2010-2012 were examined for antimicrobial resistance. Comparison of average resistance rate through the years revealed that tetracycline (47.0% and 76.1%) and streptomycin resistance (42.6% and 64.6%) was most frequently observed in cattle and pigs, respectively. Whereas, in chicken isolates, resistance against nalidixic acid (90.9%) was highest among the antimicrobials tested. Percentage of E. coli that showed multidrug resistance (resistance against ${\geq}$ three subclasses of antimicrobial agents) was 17.6% (151/860) in cattle, 69.4% (506/729) in pigs, and 86.1% (427/496) in chickens. Overall, the rates of resistance are apparently different between animal species and, in particular, resistance was less prevalent in cattle than in pigs and chickens. In conclusion, this study showed higher prevalence of resistance in commensal E. coli strains to antimicrobial agents in Korean livestock and highlighted the urgent need for measures to regulate the abuse of antimicrobial agents.

• Korean Journal of Veterinary Research
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• v.29 no.4
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• pp.487-492
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• 1989

The capsular serogroupes and drug susceptibility of 111 isolates of Pasteurella multocida from pigs with atrophic rhinitis and pneumonic lesions were investigated. Of the 111 P multocida isolates, 42 were from lung lesions, 47 from nasal turbinate lesions and the remaining 22 from the nasal swabs. P multocida isolates were typed for capsular serogroupes A by hyaluronidase inhibition of capsule and D by acriflavine auto-agglutination. Most isolates(64.9%) were type A, 23.4% were type D and the remaining 11.7% were untypable. Resistance to triple sulfa(97.3%) was most frequent, followed by resistance to tiamulin(71.2%), tylosin(56.8%), streptomycin(36.9%), and neomycin(36.0%). The majority of the organisms were susceptible in order of prevalence to baytril(100%), ampicillin(98.2%), linsmycin(97.3%), colistin(97.3%), cephalothin(94.6%), gentamicin(93.7%), amikacin(92.3%), tetracycline(91.9%), trimethoprim/sulfamethoxazole(91.0%), and kanamycin(90.1%). No differences in drug resistance in relation to capsular serogroupes of P multocida and the origin of lesions were noted. A high prevalence of multiple drug resistance was observed and the most common resistant patterns were Sss, Tm, Ty(12.6%) and Sm, Sss, Tm, Ty(8.1%) patterns.

• Korean Journal of Veterinary Service
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• v.37 no.3
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• pp.165-171
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• 2014

This study was conducted to investigate the species-specific gene detection, capsular serogroup and antimicrobial resistance pattern of Pasteurella multocida isolated from pneumonic lung lesion of swine in Gyeongbuk province. P. multocida isolates were typed for capsular serogroups by polymerase chain reaction. Of the 32 strains, 28 (87.5%) were typed serotype A, 3 (9.3%) were typed serotype D, and 1 strain was unknown (3.1%), respectively. In antimicrobial agents resistance test, almost of strains were susceptible to amoxicillin (100%), enrofloxacin (96.9%), ampicillin (93.8%), florfenicol (90.6%), chloramphenicol (90.6%) and were resistant to streptomycin (71.9%), spectinomycin (56.3%). All strains were resistant to clindamycin, erythromycin and lincomycin.

• Korean Journal of Veterinary Service
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• v.43 no.2
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• pp.53-58
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• 2020

Enterovirulent Escherichia coli are among the most important causes of diarrhea in cattles. Between January and December, 2017, a total of 150 stool specimens from cattles were investigated for enterohaemorrhagic E. coli (EHEC), enteropathogenic E. coli (EPEC), enteroaggregative E. coli (EAEC), enterotoxigenic E. coli (ETEC) and enteroinvasive E. coli (EIEC) using real-time PCR. 131 E. coli were isolated from feces. The most frequently isolated pathotype in feces was EHEC (37 isolates). EPEC, ETEC and EAEC were detected in feces with 14, 7 and 3 respectively. EIEC was not detected. Antimicrobial resistance test was performed by agar disc diffusion method with 14 antimicrobials. Enterovirulent E. coli isolates showed the highest antimicrobial resistance to ampicillin 61.3%, followed by tetracycline 54.5% and streptomycin 45.5%. They had low resistance to amikacin 11.4%. Of 44 isolates, 37 (84.1%) were resistant to more than 2 antimicrobials. futher study a highest antimicrobial susceptibility to trimethoprim/sulfamethoxazole 50.0% and florofenicol 47.7%.

• Journal of fish pathology
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• v.13 no.2
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• pp.111-119
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• 2000

One hundred and twenty three strains of bacterial flora collected from Kunsan bay and examined for drug resistance to 9 antibiotics. The isolated and examined bacteria were Vibrio spp.(44 strains), Pseudomonas spp.(42 strains), Aeromonas spp.(26 strains), Moraxella spp.(9 strains), Enterobacteria spp.(6 strains), Bordetella spp.(3 strains), Alkaligenesis spp.(3 strains), Staphylococcus spp.(3 strains), and Flavobacterium spp.(2 strains). The drugs used were Ampicillin(AM), Penicillin-G(PM), Rifampicin(RF), Streptomycin(SM), Oxolinic acid (OA), Nalidixic acid(NA), Oxytetracycline(OT), Amikacin(AK), and Enorfloxacin(EF). Forty two strains were found to be sensitive to all drugs. The remaining strains showed resistance to various combinations of drugs. Among the resistant strains were mostly restricted to AM(54 strains/43.9%), PM(47 strains/38.2%), RF(35 strains/28.4%), SM(9 strains), OA(5 strains/ 4.06%), and NA(1 strains/0.8%), in combination at high degree showing 15 different drug resistant patterns. The most frequently showed resistant patterns were AM-PM-RF(16 strains/13.4%), AM-PM(8 strains/6.5%), and PM-RF(7 strains/5.6%). These results suggested that Kunsan bay were contaminated with various strains of highly resistant strains to drugs(AM, PM and RF). These results suggest that high levels of various antibiotics have already been introduced to Kunsan bay. Furthermore it seems that chemotherapy of fish disease has become extremely difficult because of the acquirement of multi-drug resistance to wide range of antibiotics.

• Journal of Food Hygiene and Safety
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• v.13 no.3
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• pp.305-312
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• 1998

In order to investigate the species, serobiological characteristics and antibiotic sensitivity of Pseudomonas spp, we isolated Pseudomonas spp from 57 spring waters around Seoul area for spring, summer and autumn and identified Pseudomonas spp by biochemical characteristics and serological method. And also we tested the antibiotic sensitivity test by discdiffusion method. Of 57 spring waters tested, Pseudomonas spp were isolated from 33 spring waters(57.9%). Isolation rate of Pseudomonas spp in spring season was 28.1%, summer 21.1% and autumn 28.1%. Only 1 spring water was detected Pseudomonas spp in all seasons and 9 (15.8%) were detected for 2 seasons and 13 (22.8%) were for only 1 season. Isolation rate of Pseudomonas spp at Mt. Cheonggye was 50% and followed by Mt. Bookhan 35.7%, Mt. Daemo 33.3%, Mt. Dobong 29.6%, Mt. Surak 25.9%, Mt. Woomyun 22.2% and Mt. Bulam 7.4%. Of 44 Pseudomonas spp, 22 strains (50%) were identified by Ps. putida, Ps. aeruginosa, Ps. fluorescens and Ps. mendocina were identified 6 strains (13.6%), respectively. 4 strains (9.1%) were identified by Ps. aureofaciens. Of 6 Ps. aeruginosa, serotype A was 2 strains, B, E, G, and K was 1 strain, respectively. Of 44 Pseudomonas spp, resistance rate to amoxicillin was 90.9% and followed by chloramphenicol 84.1%, tetracycline 84.1%, carbenicillin 81.8%, nalidixic acid 68.2%, neomycin 38.6%, streptomycin 31.8%, gentamicin 4.6%, kanamycin 4.6% and colistin 2.3%. Ps. aeruginosa was more sensitive to carbenicillin than other Pseudomonas spp isolated from spring waters in Seoul area but more resistant to kanamycin, and Ps. aureofaciens was no resistant to streptomycin. Among multiple drug resistance, resistance to 5 drugs was 31.8%, 4 drugs 15.9%, 7 drugs 13.6%, 1 drug and 2 drugs 4.6%, and 8 drugs 2.3%, respectively. The multiple resistance patterns detected highestly were NA-CB-C-TE-AMC (18.2%), NA-CB-N-C-TE-AMC (13.6%), CBC-TE-AMC (11.4%) and NA-CB-N-C-TE-AMC-S (9.1%).