보육시설 유아 사용 수건의 미생물 분포 및 독소 특성

김중범,김난영,강석호,도영숙,엄미나,윤미혜,이정복 한국식품위생안전성학회 2013 한국식품위생안전성학회지 Vol.28 No.2

This study was conducted to evaluate the microbiological contamination on commonly used hand towels in the child care centers and to investigate the toxin gene and toxin production ability of food-borne pathogens. A total of 22 commonly used hand towels including 7 for before use and 15 for during use were tested. The average number of total aerobic bacteria and fungi were 6.2 log CFU/100 cm2 and 4.1 log CFU/100 cm2. Coliform bacteria were detected in 4 out of 7 before used towels (57.1%) and all of during used towels (100%). These results showed that the sanitary conditions of hand towels in the child care centers should be improved promptly. Among the pathogenic bacteria, Staph. aureus and B. cereus without Salmonella spp. were detected in 5 (22.7%) and 11 (50.0%) out of 22 hand towels. All of Staphy. aureus isolated in this study did not possess any toxin genes and did not produce enterotoxin. The detection rate of hblC, hblD, and hblA toxin genes in B. cereus was 72.7, 72.7, and 54.5% respectively. The possession rate of nheA, nheB, and nheC toxin genes showed 81.8, 72.7, and 54.5% respectively. The cytK and entFM toxin genes were presented at 45.5 and 90.0% in B. cereus. The HBL was detected in 8 out of 11 B. cereus isolates (72.7%) and 5 B. cereus isolates produced NHE (45.5%). Ten out of eleven B. cereus isolates (90.9%) produced one or more enterotoxin such as HBL and NHE. From the results, using a private hand towel or paper towel is required to prevent the cross-contamination between commonly used hand towel and children's hands in the child care center. 어린이집 유아들이 공용으로 사용하는 수건의 미생물 오염도와 분리된 식중독 미생물의 장독소 유전자 및 장독소생산 특성을 분석하여 어린이집 유아 사용 수건의 위생안전성을 확보하고자 어린이가 손 씻은 후 공용으로 사용하는 수건 22개 (사용 전 7개, 사용 중 15개)를 연구대상으로 하였다. 일반세균수는 평균 6.2 log CFU/100 cm2로 검출되었고 진균수는 평균 4.1 log CFU/100 cm2로 검출되었으며 대장균군은 사용 전 수건의 경우 7건 중 4건 (57.1%),사용 중인 수건의 경우 15건 모두에서 (100%) 검출되었다. 어린이 사용 수건의 미생물 오염도가 높게 나타나 수건의 위생적인 살균 세탁 및 상대습도가 낮은 곳에 보관하는 등의 보관 방법 개선이 필요한 것으로 판단되었다. Salmonella spp.의 경우 실험에 사용된 모든 수건에서 검출되지 않았으나, Staph. aureus는 22건 중 5건 (22.7%),B. cereus는 11건 (50.0%)에서 검출되어 B. cereus 오염이가장 심각한 것으로 나타났다. Staph. aureus 장독소 유전자와 독소 단백질은 모두 불검출 되었으나 분리 동정된11균주의 B. cereus 장독소 유전자 실험 결과 hblC, hblD,hblA 유전자가 각각 72.7, 72.7, 54.5% 검출되고 nheA,nheB, nheC 유전자가 각각 81.8, 72.7, 54.5% 검출되었으며 cytK, entFM 장독소 유전자는 각각 45.5, 90.0% 검출되었다. B. cereus 장독소 실험결과 HBL 장독소는 11균주중 8균주 (72.7%), NHE 장독소는 5균주 (45.5%) 검출되었고 HBL과 NHE 장독소 중 하나 이상을 생산하는 B. cereus 균주는 10균주 (90.9%)로 나타났다. 수건에 오염된B. cereus 균주의 교차오염에 따른 식중독 위험성이 상존하는 것으로 나타나 개인별 수건 또는 종이 타올 사용을고려하여야 할 것으로 판단되었다.

Comparison of Biochemical Profiles with Biogroups for the Identification of Cronobacter spp. (Enterobacter sakazakii)

김중범,Yong-Bae Park,Woon-Ho Kim,Ki-Cheol Kim,Hong-Rae Jeong,Dae-Hwan Kim,Suk-Ho Kang,Kum-Chan Yong,Mi-Hye Yoon,Yong-Chul Park 한국식품위생안전성학회 2009 한국식품위생안전성학회지 Vol.24 No.4

The objectives of this study were to compare the biochemical profiles with biogroups for the identification of Cronobacter spp. (formally known as Enterobacter sakazakii) isolates using biochemical identification kits. A total of 38 Cronobacter spp. contained 5 clinical, 31 food, and 2 environmental isolates were used. All isolates were identified as Cronobacter spp. with the Vitek II system and ID 32E kit. The API 20E kit identified all isolates as Cronobacter spp. but the percentage identification was 51.1% for 16 of 38 isolates. These strains were contained to Biogroup 2, 9, 10, and 11. The utilization of inositol is a factor determining the percentage identification of Cronobacter spp. with the API 20E kit.

IKONOS 위성영상과 GPS를 이용한 소나무 재선충 피해지역 추출에 관한 연구

김중범,조명희,김인호,김영걸 한국산림과학회 2003 한국산림과학회지 Vol.92 No.4

보육시설 급식실 실내공기에서 분리된 식중독 세균의 독소 유전자 및 독소 생산 특성

김중범,김종찬,Kim, Jung-Beom,Kim, Jong-Chan 한국환경보건학회 2012 한국환경보건학회지 Vol.38 No.6

Objectives: This study was conducted in order to evaluate the microbiological contamination of the indoor air of the lunchrooms at child care centers and investigate the toxin genes and toxin production ability of food-borne pathogens. Methods: A total of 64 child care centers were sampled to test total aerobic bacteria, coliform bacteria, fungi, Staphylococcus aureus, Bacillus cereus and Salmonella spp. according to the Korea Food Code. All toxin genes of pathogens were detected using the Polymerase Chain Reaction method. The Sthaph. aureus enterotoxin was detected by a Staphylococcus aureus enterotoxin-reversed passive latex agglutination kit. The heamolysin BL (HBL) and non-heamolytic enterotoxin (NHE) produced by B. cereus were detected using a B. cereus enterotoxin-reversed passive latex agglutination kit and Bacillus diarrheal enterotoxin visual immunoassay kit, respectively. Results: The means of total aerobic bacteria and coliform bacteria were $1.91{\pm}1.84$ log CFU/plate and $0.47{\pm}0.62$ log CFU/plate, respectively. The mean of fungi also showed $0.59{\pm}0.71$ log CFU/plate. Among the pathogenic bacteria tested in this study, Staphy. aureus and B. cereus were detected in four (6.3%) and 21 (32.8%) out of 64 indoor air samples from lunchrooms in child care centers, respectively. All Staphy. aureus tested in this study possessed no toxin genes and did not produce enterotoxin. The detection rate of nheABC, hblCDA, entFM and ces toxin gene in B. cereus was 100, 57.1, 76.2 and 0%, respectively. B. cereus isolates were classified into four groups according to the presence or absence of toxin genes. The nheABC gene was the major toxin gene among B. cereus tested in this study. The HBL was detected in 11 out of 21 B. cereus isolates (52.4%) and three B. cereus isolates produced NHE (14.3%). Conclusion: The results indicated that the contamination by microorganisms in the indoor air of lunchrooms was unqualified to supply safe catering in child care centers. The ongoing control of indoor air quality is required.

어린이집 유아 손의 미생물학적 위해 평가 및 손 씻기 교육의 효과

김중범,허은선,강석호,김대환,도영숙,박포현,박용배,윤미혜,이정복 한국식품위생안전성학회 2012 한국식품위생안전성학회지 Vol.27 No.1

This study was conducted to evaluate the microbiological hazard on nursery school children's hands and to investigate the reduction effect of hand washing education. A total of 59 nursery school children's hands were tested. The average number of total aerobic bacteria was 3.72 ± 0.38 log CFU/hand. Five children's hands(2male and 3 female) were positive(14.3%) for the coliform bacteria. These results showed that hand washing education are required repetitively. Among the pathogenic bacteria tested in this study, Staphylococcus aureus and Bacillus cereus were detected in 9(25.7%) and 16(45.7%) out of 35 their hands, respectively. Twelve out of sixteen B. cereus isolates(70.0%) produced enterotoxin. The results indicate that the hand hygiene of nursery school children needs to be improved. Comparing before and after hand washing in educated and non-educated group, the reduction effect of total aerobic bacteria on their hands was 0.42 and 0.60 log CFU/hand, respectively. The educated group showed 0.18log CFU/hand higher reduction effect than non-educated group but microorganism did not eliminate perfectly. From the results, using a hand sanitizer after washing with soap and the continuous hand washing education are required to control the contaminated bacteria on nursery school children's hands.

금속표면이 항생제 내성균주의 생육억제에 미치는 영향

김중범,김재광,김현정,조은정,박연준,이혜경 대한임상미생물학회 2018 Annals of clinical microbiology Vol.21 No.4

Background: The aim of this study was to comparatively evaluate the bactericidal effects of copper, brass (copper 78%, tin 22%), and stainless steel against methicillin-resistant Staphylococcus aureus (MRSA), vancomycin-resistant Enterococcus faecium (VREFM), and multidrug-resistant Pseudomonas aeruginosa (MRPA). Methods: The isolates (MRSA, VREFM, MRPA) used in this study were mixed wild type 3 strains isolated from patients treated at Uijeongbu St. Mary’s Hospital in 2017. These strains showed patterns of multidrug resistance. The lyophilized strains were inoculated into and incubated for 24 hr in tryptic soy broth at 35°C. The initial bacterial inoculum concentration was adjusted to 105 CFU/mL. A 100-mL bacterial suspension was incubated in containers made of brass (copper 78%, tin 22%), copper (above 99% purity), and stainless steel at 35°C. Viable counts of bacteria strains were measured for 9 days. Results: In this study, the bactericidal effects of copper and brass on MRSA, VREFM, and MRPA were verified. The bactericidal effect of stainless steel was much weaker than those of copper and brass. The bactericidal effect was stronger on MRPA than on MRSA or VREFM. Conclusion: To prevent cross infection of multidrug resistant bacteria in hospitals, further studies of longer duration are needed for testing of copper materials on objects such as door knobs, faucets, and bed rails. (Ann Clin Microbiol 2018;21:-85)

열수(熱水)와 마이크로웨이브 가열이 조제분유 및 선식 용해 중 Enterobacter sakazakii 사멸에 미치는 영향

김중범,박용배,이명진,김기철,허정원,김대환,이정복,김종찬,최재호,오덕환 한국식품위생안전성학회 2008 한국식품위생안전성학회지 Vol.23 No.2

Enterobacter sakazakii was initially referred to as yellow-pigmented Enterobacter cloacae and reclassified in 1980. E. sakazakii infection cause life-threatening meningitis, septicemia, and necrotizing enterocolitis in infants. Powdered infant formula (PIF) and baby foods may be the important vehicle of E. sakazakii infection. It has been reported that E. sakazakii was isolated from PIF and sunsik ingredients produced in Korea. Some infants have been fed sunsik as a weaning diet. Therefore, it is necessary that this organism should be inactivated on preparing PIF and sunsik at homes and in hospitals. The cocktail of three Korean E. sakazakii strains (human, sunsik and soil isolates) were used to investigate the inactivation of this organism with hot water at 50, 60, 65, 70 and 80℃ and microwave heating for 60, 75, 90, 105 and 120 sec. Reconstituted PIF and sunsik were inoculated with cocktailed vegetative cells of E. sakazakii at 6 log CFU/mL. Thermal inactivation of vegetative cells of E. sakazakii were achieved by reconstituted PIF and sunsik with hot water at 60℃ or greater and with microwave heating at 2,450 MHz for 75 sec or longer. Considering that biofilm formation of E. sakazakii was adapted to survive the dry environment that is PIF and sunsik and thermal resistance increased, it is suggested that inactivation of E. sakazakii was used by hot water at 70℃ or greater and microwave heating for 90 sec or longer. Reconstituted PIF and sunsik were inoculated with cocktailed vegetative cells of E. sakazakii at 2 to 3 log CFU/mL to investigate the growth curve of this organism and stored at 5, 10, 15, 20, 25, 30 and 35℃. Viable counts slightly changed at 5, 10℃ during 48 h but grew at 15℃ or greater. Considering that E. sakazakii is able to grow in infant formula milk at refrigerator temperature, reconstituted PIF and sunsik that are not immediately consumed should be discarded or stored at refrigeration temperatures within 24 h. Enterobacter sakazakii was initially referred to as yellow-pigmented Enterobacter cloacae and reclassified in 1980. E. sakazakii infection cause life-threatening meningitis, septicemia, and necrotizing enterocolitis in infants. Powdered infant formula (PIF) and baby foods may be the important vehicle of E. sakazakii infection. It has been reported that E. sakazakii was isolated from PIF and sunsik ingredients produced in Korea. Some infants have been fed sunsik as a weaning diet. Therefore, it is necessary that this organism should be inactivated on preparing PIF and sunsik at homes and in hospitals. The cocktail of three Korean E. sakazakii strains (human, sunsik and soil isolates) were used to investigate the inactivation of this organism with hot water at 50, 60, 65, 70 and 80℃ and microwave heating for 60, 75, 90, 105 and 120 sec. Reconstituted PIF and sunsik were inoculated with cocktailed vegetative cells of E. sakazakii at 6 log CFU/mL. Thermal inactivation of vegetative cells of E. sakazakii were achieved by reconstituted PIF and sunsik with hot water at 60℃ or greater and with microwave heating at 2,450 MHz for 75 sec or longer. Considering that biofilm formation of E. sakazakii was adapted to survive the dry environment that is PIF and sunsik and thermal resistance increased, it is suggested that inactivation of E. sakazakii was used by hot water at 70℃ or greater and microwave heating for 90 sec or longer. Reconstituted PIF and sunsik were inoculated with cocktailed vegetative cells of E. sakazakii at 2 to 3 log CFU/mL to investigate the growth curve of this organism and stored at 5, 10, 15, 20, 25, 30 and 35℃. Viable counts slightly changed at 5, 10℃ during 48 h but grew at 15℃ or greater. Considering that E. sakazakii is able to grow in infant formula milk at refrigerator temperature, reconstituted PIF and sunsik that are not immediately consumed should be discarded or stored at refrigeration temperatures within 24 h.

보육시설 급식실 실내 환경에서 분리된 식중독 미생물의 항생제 내성 특성

김중범,김종찬,Kim, Jung-Beom,Kim, Jong-Chan 한국환경보건학회 2012 한국환경보건학회지 Vol.38 No.5

Objectives: This study was performed in order to evaluate antibiotic resistance and analyze the multiple antibiotic resistance of food-borne pathogens isolated from indoor air and an air cleaner at a lunch room in a child care center. Methods: An antibiotic test of food-borne pathogens, including four Staphylococcus aureus and 23 Bacillus cereus was conducted through the disk diffusion method from Clinical and Laboratory Standard Institute. Results: All Staph. aureus was resistant to Ampicillin and Penicillin, while B. cereus was also resistant to Ampicillin, Cefepime and Penicillin. All isolates showed Vancomycin susceptibility but three out of four Staph. aureus and all B. cereus were resistant to Oxacillin. Staph. aureus and B. cereus presented two or more multiple antibiotic resistances. Conclusions: The results indicated that food-borne pathogens isolated from indoor air and an air cleaner at a lunch room in a child care center showed multiple antibiotic resistances. The repeated control of indoor environment quality is required and continuous surveillance of antibiotic resistant strains is demanded.

살균 조건이 세척 도구 중 미생물 저감화에 미치는 영향

김중범,임지유,김채영,김은영,김민진 한국식품위생안전성학회 2022 한국식품위생안전성학회지 Vol.37 No.5

In this study, we compared the microbial reduction effects of drying, hot water, and microwave sterilization in scourers and dishcloths to suggest a most suitable sterilization method. Three scourer types (silver, copper, and mesh) were used, and three dishcloth types (silver, bamboo, and cotton) were used. Drying time dependent reduction in Escherichia coli was high in silver and copper scourers, but minimal bacterial reduction was obtained against Bacillus cereus in all scourers and dishcloths. In scourers, E. coli was not detected after ≥30 s of hot water sterilization at 77o C, and B. cereus was not detected after ≥60 s of hot water sterilization at 100o C. In dishcloths, E. coli was not detected after hot water sterilization at 77o C for ≥30 s, but B. cereus was detected after hot water sterilization at 100o C for ≥60 s. In scourers, E. coli was not detected after microwave sterilization at 700 W for 3 min, but B. cereus was detected. In dishcloths, E. coli was not detected after microwave sterilization with 700 W for ≥1 min, but B. cereus was detected in the cotton dishcloth even after sterilization for 3 min. In conclusion, the use of antimicrobial scourers (silver and copper) and dishcloths (silver and bamboo) are not sufficient to reduce the microbial contamination. The guideline provided by the Ministry of Food and Drug Safety suggesting dishcloth sterilization via hot water at 100o C for 30 s was also found to be insufficient. Based on our research, we suggest that the most effective methods of microbial management are submerging scourers in hot water at 100o C for ≥1 min, and sterilizing dishcloths for ≥3 min using a 700 W microwave.

Inhibitory Effects of Copper, Brass, and Stainless Steel Surfaces on Multidrug-Resistant Microorganisms

김중범,김재광,이재웅,채현석,이혜경,박연준 대한임상미생물학회 2022 Annals of clinical microbiology Vol.25 No.2

Background: The aim of this study was to analyze the inhibitory effects of copper, brass(78% copper, 22% tin), and stainless steel surfaces on multidrug-resistant Acinetobacterbaumannii (MRAB), extended-spectrum beta-lactamase (ESBL) Escherichia coli , andcarbapenem-resistant Klebsiella pneumoniae (CRKP). Methods: MRAB, ESBL E. coli, and CRKP were isolated at Uijeongbu St. Mary's Hospital in 2020. A. baumannii ATCC BAA-747, E. coli ATCC 25922, and K. pneumoniae ATCC 700603 were used asreference strains. The initial bacterial cell count of each inoculum was adjusted to 8 log CFU/mLusing phosphate buffered saline, Copper, brass, and stainless steel plates were inoculated with 9mL of MRAB, ESBL E. coli, and CRKP inoculum solutions. The bacterial cell count was measuredfrom the beginning to the 20th day in an incubator maintained at 35°C. Results: MRAB, ESBL E. coli , and CRKP isolates were not detected on the copper andbrass plates after 4, 5.5, and 6.5 hours, respectively. MRAB, ESBL E. coli, and CRKP isolateswere not detected on the stainless steel plate after 15, 20, and 20 days, respectively. Thebactericidal effects of copper and brass were much stronger than those of stainless steel. Conclusion: The use of copper and copper alloys should be considered to prevent crossinfectionin hospitals.