자돈에서의 연쇄구균성 감염증에 관한 연구 I. 이환돈에서의 streptococcus suis type II에 의한 돼지뇌막염의 실태와 약제 감수성

석호봉(Ho Bong SEOK),예재길(Jae Gil YEH) 한국예방수의학회 1990 예방수의학회지 Vol.14 No.1

Investigations into the bacteriology and epidemiological features of streptococcus suis typeⅡ infections, especially in naturally-occurring field outbreaks of meningitis and its carrier state were carried out from June 1987 to December 1989 at intensive pig farms in parts of Seoul, Kyounggi, Chungchong and Kyoungnam areas. Also determined were isolated frequency of streptococci in various sources of effected pigs and antibiotics susceptibilities of the isolates. The results obtained were summarized as follows: 1. Streptococci were isolated from porcine specimen submitted to the lab. from affected pig farms and 48 strains isolated from pigs of different clinical symptoms belonged to 14 brains, 23 lungs and 11 feces. 2. The brain diseased pigs ranged mostly from 30 to 50 days of age and main clinical symptoms of the disease were CNS sign and meningitis. The morbidity and mortality of this pig weaned in a part of pig farms were 4 to 10 and 30 percent, respectively. 3. Most of brain-origin streptococci(78.7%) was belonged to Lancefield group D and identified as Streptococcus suis typeⅡ by biological and additional serological examinations. Other 3 strains were divided to group C, group F and group G.

자돈에서의 연쇄구균성 감염증에 관한 연구 II. 정상돈에서의 streptococcus suis type II에 의한 감염실태와 약제감수성

석호봉(Ho Bong Seok),이관형(Kwan Hyeong Lee),예재길(Jae Gil Yeh) 한국예방수의학회 1992 예방수의학회지 Vol.16 No.3

Investigation into the bacteriology and epidemiological features of Streptococcus suis type Ⅱ infections, in particular, in clinically healthy pigs were carried out from April 1990 to April 1992 at 7 intensive pig farms of Chungnam and Kyounggi areas. Also determined were isolated frequency of streptococci in various sources of effected Pigs and antibiotics susceptibilties of the isolates. The results obtained were summarized as follows : 1. Streptococci isolated from various sample of clinically healthy pigs belonged to 190 strains of nasal discharge, 8 of brains, 2 of bloods, and 1 strain each from lung, cardiac fluid, salivary gland and small intestine. 2. Out of 204 hemolytic streptococci, 55 isolates of them (27.0%) were Str. suis type Ⅱ. 3. Prevalance of Str. suis type Ⅱ in five to seven week-old pigs were higher than them of eight week above and four week less. 4. In regional distribution of 55 Str. suis type Ⅱ, the isolating rates of Cheonan and Asan area were higher than that of Gongju and Pyongtak. 5. Among 204 hemolytic streptococci, 61 isolates of them (29.9%) were Lancefield serogroup D, 46 (22.5%) were serogroup C and 22 (10.8%) were serogroup E, the remaining 75 isolates (36.8%) were ungrouping, respectively. In additional results of serogroup D isolates by biological and serological examination, 55 were identified to Str. suis type Ⅱ and 6 were to Str. suis type Ⅰ. 6. Most strains of 133 streptococci were susceptible to ampicillin (93.2%), chloramphenicol (92.5%) and cephalothin (90.2%) while they were resistant to erythromycin (78.2%) and streptomycin (73.3%). These resuts were similar to each group of groupable strains.

돼지 다발성장막염 및 관절염(glässer씨병)의 원인균 조사 및 분리균의 병발성에 관한 연구

석호봉(Ho Bong Seok),이관형(Kwan Hyeong Lee),이난주(Ran Ju Lee),예재길(Jae Gil Yeh) 한국예방수의학회 1993 예방수의학회지 Vol.17 No.1

Investigation into the bacteriology and epidemiology features of polyserositis and polyarthritis(Glässer disease) were carried out at 13 intensive pig farms of Chungnam and Kyounggi areas. Also determined were isolated frequency of hemophilus-like organisms in various sources of pigs, antibiotics susceptibilities of the isolates and pathogenesis of guinea pigs experimentally infected with isolates. The results obtained were summarized as follows: 1. Out of 75 hemophilus-like organisms isolated from 13 pig farms, 13 isolates of them were showed in same biological properties with standard strains. 2. Hemophilus-like organisms isolated from various samples of pigs belonged to 53 of 238 nasal discharges(22,3% ), 9 of 97 lungs(9.3%), 8 of 79 thoracic fluids(10.1%) and 1 of 22 others(4.6%), respectively. Urease-negative strains isolated from 6 of nasal discharge and 7 of lung (plus 5 strains from Bayer). 3. In regional distribution of 85 hemophilus-like organisms, the isolating rates of Pyeongtaek(26.3%) and Gongju(25%) were higher than that of Cheonan(17.5%), Hongseong(5.7%) and Asan(5%). Urease negative strains isolated from piggeries of Pyeongtaek(5), Asan(2) and Gongju(1) areas. 4. Among 13 farms, 9 farms were affected within the limits of 4.1%-47.2%, which the rates was decreased in good managing status, while increased in poor status or in respiratory symptoms. 5. The prevalence of isolates in four weeks of age pigs(31%) were the highest, in five weeks(22.5%) to in eight weeks(22.2%) to next higher ranks but lower in four weeks less(9.3%) and in eight weeks above(8.9%). 6. All isolates were highly susceptible to chloramphenicol, cephalothin, ampicillin, although they were highly resistant to streptomycin, neomycin, kanamycin. The drug susceptible properties against strains isolated from Japanese and Korean were showed in similar results. 7. The similar results of the pathological symptoms, bacteriological recovery and anatomic lesions after injection experimentally in guinea pigs with two urease-negative isolates and one Japanese strain(HPS) were discussed. The gross pathological finding of pig cases occurred naturally in pig farms was finally observed.

Bovine Viral Diarrhea Virus에 대한 혈중중화항체 조사

석호봉,Seok Ho-Bong 대한수의사회 1984 대한수의사회지 Vol.20 No.7

A total of 1,395 cattle of domestic and foreign origin was tested for the presence of antibody against BVD virus by a micro-neutralization test. Of 1,295 sera collected from cattle born in Korea, $38.4\%$ had antibody to BVD virus. Korean nativ

대단위(大單位) 낙농목장(酪農牧場)에서의 소전염성결막각막염(傳染性結膜角膜炎)(IBK)의 임상적(臨床的) 및 세균학적(細菌學的) 관찰(觀察)

석호봉,Seok, Ho-bong 대한수의학회 1985 大韓獸醫學會誌 Vol.25 No.1

A group of 80 Holstein calves, many with clinical signs of infectious bovine keratoconjunctivitis in summer seasons, was assembled for bacteriologic and ophthalmologic studies at an integrated dairy farm. Observations were started from 1980 to 1984 but bacteriological study was only carried out from thor spring in 1981 and continued during the Autumn in 1981. Corneal lesions and drugs sensitivity were also observed and the results obtained were as follows: 1. Occurrences of IBK-affected cattle during the 5 years were predominent to calves in summer. 2. Among 142 eyes from 80 cattle, 53 isolates of Moraxella bovis(37.3%) were isolated from 37 cattle(46.3%). The prevalence of the infection for clinical eyes were higher than nonclinical eyes calves. 3. Miscellaneous organisms were found from age groups of 5 months to 9 months old. It were 8 hemolytic Neisseria spp., 3 Fungi, Mycoplasma sp. and 1 Pseudomonas sp., but 9 samples were unknown. 4. Prevalence of infection with M. bovis in bilateral clinical eyes were higher than unilateral eyes. 5. Incidence of corneal lesion was predominent in early stage as a watery tears(21.0%) and late stage as a leukomas of corneal opacity(22.8%). 6. The number of isolations of M. bovis and incidence of IBK varied from year to year; Higher incidence of IBK clinical signs were showed in calves from 5 months to 10 months old and the number of isolations of M. bovis was declined in order 8 months(100.0%), 4 months(75.0%), 5 months(66.6%) and 8 months(66.6%) old calves. 7. Chloramphenicol, Nitrofurantoin and Cephalothin were highly sensitive against M. bovis isolates and then Tetracycline, Neomycin, Erythromycin and Kanamycin were intermediate but low sensitive to Streptomycin, Colistin and Penicillin.

Crocin 첨가배지(添加培地)에서의 우유방염유래(牛乳房炎由來) Streptococcus의 색소형성(色素形成)에 관한 연구(硏究)

석호봉,김동성,김상열,이택주,Seok, Ho Bong,Kim, Dong Sung,Kim, Sang Youl,Lee, Taik Joo 대한수의학회 1976 大韓獸醫學會誌 Vol.16 No.2

On the basis of pigment production on brain heart infusion agar medium containing crocin, differentiation of mastitic streptococcus was investigated. Intensive crocin reaction was showed in braille heart infusion agar when maximum volume of gardenia powder was 5.0 mg/ml and dark-violet pigmentation of Str. uberis and Group D (Str. facalis) Streptococcus were differentiated from negative strains of Str. dysgalactiae. Also, although most of Str. agalactiae was producted pigment, a few was not affected with the crocin reaction.

Lancefield Grouping에 의한 유방염유래(乳房炎由來) Streptococcus의 동정(同定)과 항생물질(抗生物質)에 대한 감수성조사(感受性調査)

석호봉,이현수,Seok, Ho Bong,Lee, Hyun Soo 대한수의학회 1975 大韓獸醫學會誌 Vol.15 No.1

A Total of 173 streptococci isolated from 536 dairy cattle in Gyeonggi Province identified by Lancefield serological reaction and other biological properties. Antibiotics sensitivity test was also examined and the results obtained were as follows: 1. A total of 173 isolates of 167 strains (96.5%) were reacted with group A,B,C,D,E and G antisera. 2. Of the 167 positive strains, 75 strains were identified to Streptooccus uberis, 56 to Streptococcus agalactiage and 26 to Streptococcus dysgactiae, respectively. Also, Sreptococcus pyogenes, group D and group G streptococci were rarely isolated. 3. In results of antibiotic sensitivity tests, the most isolates were sensitive to leucomycin and erythromycin but less sensitive to streptomycin. and kanamycin.

Investigation of seroepidemiology of Mycoplasma hyopneumoniae infection and establishment of on-farm eradication protocol

석호봉,주한수,Seok, Ho-bong,Joo, Han-soo The Korean Society of Veterinary Science 1999 大韓獸醫學會誌 Vol.39 No.6

The purposes of this study are to examine seroprevalence of Mycoplasma hyopneumoniae infection in pigs of different age groups, and retrospectively determine if nursery depopulation (ND) could influence the seroprevalence of M hyopneumoniae infection in nurseries. Sera of 4, 8, 12, 16, and 20 weeks old pigs from 7 farms were first selected from a serum bank to examine serologic profiles for M hyopneumoniae infections. Availability of representative sera in the serum bank was a major criterion for farm selection. The sera were tested for M hyopneumoniae antibodies by an enzyme linked immunosorbent assay (ELISA) using Tween-20 extracted antigen. Serum samples were also selected from 15 of 34 swine farms that previously participated in a ND study. In order to evaluate M hyopneumoniae infection following ND, ELISA was performed with sera of 8~10 weeks old nursery pigs collected prior to and after ND for up to 12 months from the 15 farms. Serological profiles showed positive ELISA titers for 2 of 7 farms at 8 weeks, 4 of 7 farms at 12 weeks, 6 of 7 farms at 16 weeks, 6 of 6 farms at 20 weeks of age. Prior to ND, 11 of the 15 farms had positive titers in sera of 8~10 weeks old pigs. Sera of 8~10 weeks old pigs collected from 7 of the 11 farms (63.6%) were ELISA antibody negative for up to 12 months following ND. In conclusion, seroconversion to M hyopneumoniae was detected commonly between 10~16 weeks of age, indicating the occurrence of natural infection during the nursery age. The ND appeared to be an effective method to prevent M hyopneumoniae infection within the nursery pig in some farms.

성환지역(成歡地域)의 유우유방염(乳牛乳房炎)에 관한 연구(硏究) 1. 유방염(乳房炎)의 발생실태(發生實態)와 그 원인균(原因菌) 조사(調査)

석호봉,이광원,오성룡,Seok, Ho Bong,Lee, Kwang Won,Oh, Seong Yong 대한수의학회 1981 大韓獸醫學會誌 Vol.21 No.2

A total of 210 dairy cows of Seongwhan area were epidemiologically investigated for mastitis by Milk Quality Test(MQT) method. Milk samples from cows infected with mastitis were also bacteriologically studied. Seventy four (42.5%) of 174 dairy cows were positive for mastitis and fifty nine (79.7%) among them were infected with subclinical mastitis and fifteen (20.3%) were clinical mastitis. High infective rate were shown on August (48.7%) and July (45.7%) and it was lowered on December (35.8%). The incidence rate of subclinical mastitis for herd shown tendency of increase at the barn in which located on lower place (30.7~43.9%), whereas, the barn in which was on higher place and with bucket type milking system shown tendency of decrease causative organisms. A total of 230 strains of etiological agents were isolated from 578 infected duarters which shown MQT score (+) or more. The relevant causative organisms isolated in this study were Staphylococcus aureus (18.3%), Staphylococcus epidermidis (16.9%), fungi (16.5%), Pseudomonas aeruginosa (15.2%), Escherichia coli (7.8%) and Serratia marcescens (2.27), respectively.

도축돈의 마이코플라즈마성 폐렴에 관한 연구 1. 육안적 폐병변과 dot-ELISA에 의한 계절별 조사

임영택,석호봉,Lim, Young-Taek,Seok, Ho-Bong 대한수의학회 2002 大韓獸醫學會誌 Vol.42 No.2

We report the seasonal prevalence of the mycoplasmal pneumoniae of swine (MPS) in slaughter pigs from July of 1999 to June of 2000. Gross finding of lung lesion observed and examined by dot-ELISA. In gross finding of lung lesion from 750 pig samples, 465 (62.0%) was MPS, and 129 (17.2%) was single or double infection with actinobacillosis and pasturellosis. However, 156 (20.8%) had no lesion. In seasonal detection, the prevalence was found to be winter (69.5%), autumn (63.5%), summer (60.0%) and spring (54.7%) in orderly frequency. In dot-ELISA, the result was showed the positive reaction (x16>titre) with 58.0% and negative (x4<titer) with 42.0% among a total of 1,710 pigs from 62 farms. In seasonal patterns by dot-ELISA, the prevalence was increased orderly in autumn (61.2%), winter (59.4%), spring (57.8%) and summer (54.4%). Accordingly, the new preventive strategies for MPS are necessary because the prevalence was relatively high especially in winter and autumn.