• 대한임상검사과학회지
• /
• 제47권4호
• /
• pp.279-285
• /
• 2015

본 연구는 경기도와 인천지역의 치과 병원급 19개 기관, 의원급 28개 기관 진료실의 유닛체어 등받이, 라이트 손잡이, 타구대 표면의 검체를 채취하여 실험하였다. 우선 치과 진료실 내 표면의 세균수는 타구대 $44.82{\times}10^3CFU/mL$, 라이트 손잡이 $5.47{\times}10^3CFU/mL$ 유닛체어 $16.28{\times}10^3CFU/mL$로 타구대가 높게 측정되었으며, 의료기관의 규모로는 병원급이 높게 나타났고, 환자수가 많을수록 타구대에서 세균수가 높게 측정되었다. 표면 세균 동정 결과는 Gram positive 균주는 47.3%, Gram negative 균주는 52.7%였으며, Gram positive 균주 중 Micrococcus luteus 10.9%, Bacillus pumilus, Staphylococcus aureus 균주가 각각 3.6%로 확인되었다. Gram negative 균주로는 Acinetobacter ursingii 5.5%로 가장 많이 검출되었으며, Brevundimonas diminuta, Chryseobacterium (Flavo.) indologenes (CDC IIb), Methylobacterium sp.가 각각 4.5%로 나타났다. 이에 본 연구는 치과 진료실 내 표면 세균 오염도를 측정하고, 세균의 종류를 확인함으로써 진료실 내 감염관리의 중요성을 인식시키고, 감염방지에 대한 구체적인 계획 수립의 기초 자료가 될 것으로 사료된다.

• 한국환경보건학회지
• /
• 제40권2호
• /
• pp.98-104
• /
• 2014

Objectives: The purpose of this study was to determine airborne bioaerosols such as bacteria and fungi in the kitchens of restaurants, and to assess the effects of thermal factors on the levels of the bioaerosols. Methods: Air samples were taken from kitchens of nine restaurants. An Anderson type air sampler was used for sampling and measurements. Petri dishes filled with a microbiological culture medium (trypticase soy agar for bacteria and Sabouraud dextrose agar for fungi) were used as the sampling surface. Results: The levels of bacterial aerosol measured were $10-10^3CFU/m^3$ and fungal aerosol $10-10^2CFU/m^3$, respectively The mean values of air temperature and relative humidity in the kitchens were $24.6^{\circ}C$ and 46.4%, respectively. Overall, the levels of bacterial aerosol varied by the restaurant type, and fungal aerosol by the business period (p < 0.05). The main effect of air temperature and interaction effect of air temperature and relative humidity onto the bacterial level were significant (p < 0.05), whereas the effects were not significant onto the fungal level. Conclusions: The results indicate a wide variation in the levels of bioaerosols among different kitchens. The observed differences in bioaerosol levels in the kitchens reflect different periods of use. The interactions of air temperature and relative humidity onto the bacterial level suggest that constant attention should be paid to avoid peaks of contamination during the summer season.

• Journal of Microbiology
• /
• 제38권2호
• /
• pp.99-104
• /
• 2000

Hydrogen peroxide has been used in cleaning the piping of an advanced high-purity water system that supplies ultra-high purity water (UHPW) for 16 megabyte DRAM semiconductor manufacturing. The level of hydrogen peroxide-resistant bacteria in UHPW water was monitored prior to and after disinfecting the piping with hydrogen peroxide. Most of the bacteria isolated after hydrogen peroxide disinfection were highly resistant to hydrogen peroxide. However, the percentage of resistant bacteria decreased with time. The hydrogen peroxide-resistant bacteria were identified as Micrococcus luteus, Bacillus cereus, Alcaligenes latus, Xanthomonas sp. and Flavobacterium indologenes. The susceptibility of the bacteria to hydrogen peroxide was tested as either planktonic cells or attached cells on glass. Attached bacteria as the biofilm on glass exhibited increased hydrogen peroxide resistnace, with the resistance increasing with respect to the age of the biofilm regrowth on piping after hydrogen peroxide treatment. In order to optimize the cleaning strategy for piping of the high-purity water system, the disinfecting effect of hydrogen preoxide and peracetic acid on the bacteria was evaluated. The combined use of hydrogen peroxide and peracetic acid was very effective in killing attached bacteria as well as planktonic bacteria.

• 한국수산과학회지
• /
• 제55권4호
• /
• pp.437-442
• /
• 2022

Squid jeotgal is a very popular traditional, salted, and fermented seafood in Korea. Due to the development of a distribution structure, a lot of imported squid jeotgal has recently entered Korea. In this study, we analyzed and compared the microbial contamination levels of domestic and imported squid jeotgal. The total viable bacterial count in domestic and imported jeotgal was 5.20 and 5.38 log CFU/g, respectively. The highest contamination level was 6.94 log CFU/g in one of the imported squid jeotgal samples. Coliforms were not detected in domestic jeotgal but were detected at 50% with 2.21 log CFU/g in imported jeotgal. Escherichia coli and Staphylococcus aureus were not detected (ND: <1 log CFU/g) in both domestic and imported jeotgal. All samples of jeotgal were negative for Bacillus cereus and Clostridium perfringens. The microbial contamination levels determined in the current study may be utilized as primary data to execute microbial risk assessments on domestic and (or) imported jeotgal.

• 대한방사선기술학회지:방사선기술과학
• /
• 제43권5호
• /
• pp.359-365
• /
• 2020

This study aimed to investigate the causes of bacterial growth to prevent infection caused by ultrasound gel and gel containers in contact with patients during ultrasonography. To investigate bacterial contamination during manufacturing or storage, we cultured ultrasound gels originally supplied from three manufacturers. To analyze bacterial growth according to the lapse of time and frequency of use of the ultrasound gel container, the gel and container were cultured at regular intervals every week for 4 weeks. In addition, to determine the source of infection, the examiner's hand was inspected with hand plate and the degree of bacterial contamination was measured before the test. As a result of the study, bacteria were not detected in the gel provided at the initial supply, and in the gel and gel container used repeatedly for 4 weeks, the same bacteria residing on the skin were identified in the examiner's hand, such as Staphylococcus epidermidis, Micrococcus luteus, Leuconostoc mesenteroid spp cremoris, Kocuria rhizophila, and etc. Separated strains were classified as those of the low- or non-pathogenicity; however, most of these strains may render fatal consequences to patients of lower level of immunity due to acquired tolerance to antibiotics. At week 1, when the number of tests was the highest, 44 colonies were identified, and at week 4, when the number of tests was the lowest, 4 colonies were identified. As r=0.994, it was found that the number of colonies increased as the number of tests increased. In conclusion, it was confirmed that the cause of the infection was not the ultrasound gel, but the examiner's hand. The ultrasound gel or gel container may be contaminated by skin flora of examiner's hands, which can cause opportunistic infection in patients with low immunity. The ultrasound gel or gel container may be contaminated by skin flora of examiner's hands, which can cause opportunistic infection in patients with low immunity. Therefore, it was confirmed that thorough hand disinfection was necessary to block healthcare-associated infections.

• 한국수산과학회지
• /
• 제53권5호
• /
• pp.694-698
• /
• 2020

The consumption of Gwamegi, a semi-dried saury Cololabis saira, and its vegetable sides has increased owing to its availability online. Therefore, this study investigated the microbial contamination levels in Gwamegi and its accompanying vegetable sides bought online by measuring total viable bacteria, coliforms, Escherichia coli, Staphylococcus aureus and fungi. The total viable bacteria ranged from 3-5 log CFU/g. The fungi in Gwamegi and garlic were 3.4 and 3.9 log CFU/g, respectively. The positive rate of bacterial contamination was 100% (2-3 log CFU/g) in Gwamegi, cabbage Brassica rapa subsp. pekinensis, and green chili Capsicum annuum, whereas the contamination positive rate was 80% and 60% (< 2 log CFU/g) in chives Allium ascalonicum L. and garlic A. sativum L., respectively. The positive rates of E. coli were 0%, 20%, 60%, and 40% in Gwamegi, green chili, cabbage, and chives, respectively. The contamination levels of E. coli were 1-2 log CFU/g. S. aureus was detected at < 1 log CFU/g in all raw materials. The data on microbial contamination levels may be used for microbial risk assessment of Gwamegi and vegetables for controlling the level of microbial contamination and securing microbiological safety.

• Journal of Microbiology
• /
• 제45권1호
• /
• pp.1-5
• /
• 2007

The bacterial compositions between the dental unit water system and human saliva were characterized and compared by direct sequence analysis of 16S rDNA clone libraries. Based on the species richness estimation, bacterial diversity in the dental unit water system (DUW) was more diverse than that of the human saliva (HS). The Chaol estimates of species richness in HS and DUW samples were 12.0 and 72.4, respectively. The total numbers of OTUs observed in the combined libraries accounted for 83% (HS) and 59% (DUW) of the Chaol diversity estimate as defined at the 80% similarity threshold. Based on the sequence analysis, the phylum Proteobacteria was the major group in both clone libraries at phylum level. DUW clone library contained 80.0% Proteobacteria, 8.0% Bacteroides, 4.0% Nitrospira, 4.0% Firmicutes, 2.0% Planctomycetes and 2.0% Acidobacteria. On the other hand, human saliva (HS) clone library contained 55.5% Proteobacteria, 36.1% Firmicutes and 8.4% Bacteroides. The majority of bacteria identified belonged to phylum Proteobacteria in both samples. In dental unit water system (DUW), Alphaproteobacteria was detected as the major group. There was no evidence of the bacterial contamination due to a dental treatment. Most sequences were related to microorganisms derived from biofilm in oligotrophic environments.

• 식품보건융합연구
• /
• 제5권3호
• /
• pp.35-40
• /
• 2019

In this study, general bacterial counts and coliform counts, which are hygienic indicator microorganisms, were tested for candy, chocolate, and jelly which are easily available and enjoyed around. After dropping each sample on the desk, indoors, and outdoors, it is immediately collected, or washed and collected to confirm the myth of the 3-second rule. Immediately after removing the wrapping paper, each sample was dropped on the desk, indoors, and outdoors, and after 3 seconds from the moment of contact with the surface, and then collected in a sample bag using sterilized sanitary gloves. After the same operation, each sample was rinsed for 5 seconds using sterilized sanitary gloves and sterilized distilled water, and then collected in a sample bag. The number of bacteria detected in non-washing candies was 41 CFU/g at outdoor and the number of bacteria detected in non-washing chocolate was 76 CFU/g at outdoor. The number of bacteria detected in non-washing jellies was 79 CFU/g at outdoor. Coliform group was not detected in all samples. This showed good results at the level of m = 10,000 or less, which is an allowable value suggested in the Food Code. Also, effect of washing on contaminated food was confirmed. This result is remarkably low compared with the microorganism specimens shown in Food Code, and it is confirmed that contamination occurs but not high value. Therefore, the myth of the 3-second rule is true compared to the figures based on Food Code. However, it showed the characteristics of bacteria that could survive and cross-contaminate on dry food surfaces and emphasized the importance of hygiene through food contact to unsanitary surfaces to minimize the risk of food poisoning.

• 치위생과학회지
• /
• 제23권4호
• /
• pp.343-350
• /
• 2023

Background: Digital panoramic dental X-ray equipment (PDX) is frequently used by patients and dental workers for diagnosis and examination in dental institutions; however, infection control has not been properly implemented. Therefore, in this study, we aimed to systematically review the potential risk of cross-infection in the dental environment by investigating the contamination level of general aerobic bacteria and Staphylococcus aureus, which are important in hospital infections, in PDX areas that people mainly contact. Methods: This survey was conducted from March to May 2023 and covered one general hospital, three dental hospitals, and nine dental clinics equipped with PDX. Bacteria samples were collected from the left-handle, right-handle, forehead support, and head side support as the patient's contact areas, as well as the X-ray exposure switch and left-click mouse button as the dental hygienist's contact areas of the PDX. The collected bacteria were spread on Petrifilm, and colonies formed after 48 hours of culture were counted. Results: General aerobic bacteria and S. aureus were detected in all areas investigated. Significant differences in bacterial counts between different regions of the PDX were observed in both groups (p<0.001). The detection rates of general aerobic bacteria (p<0.001) and S. aureus (p<0.001) were significantly higher in the contact areas of patients than those of dental hygienists. A positive correlation was observed between the forehead and the temple region in terms of general aerobic bacteria and S. aureus detection (r=1) (p<0.01). Conclusion: Taken together, the presence of many bacteria, including S. aureus, detected in PDX indicates that PDX has a potential cross-infection risk. Our results therefore highlight the need for the development of appropriate disinfection protocols for reusable medical devices such as PDX and periodic infection prevention training for hospital-related workers, including dental hygienists.

• Environmental Analysis Health and Toxicology
• /
• 제20권4호통권51호
• /
• pp.273-277
• /
• 2005

The purpose of this investigation was to measure the level of bacterial contamination of oysters, and observe antibiotic resistance pattern of Vibro spp. found in oysters. For this experiment, 100 oysters were collected from 100 markets around seoul area from October, 2004 to January, 2005. Bacterial contaminations of the oysters were confirmed by performing the method of standard plate count and desoxycholate lactose agar plate. Total plate counts were $2.7\times$$10^{2}$$\sim$$1.2\times$$10^{5}$ cfu/g. Coliform group were $1.0\times$$1.0^{1}$$\sim$$3.2\times$$10^{5}$ cfu/g. Results have shown that Vibrio spp. was present in $64\%$ of the 100 sampls. Antibiotic resistance pattern of Vibrio spp. showed that $MIC_{50}$ of chloramphenicol was 0.2 g/mL, $MIC_{90}$ was 25 $\mu$g/mL, and $MIC_{50}$ of tetracycline was < 0.05 $\mu$g/mL, $MIC_{90}$ was 25 $\mu$g/mL, and $MIC_{50}$ of ciprofloxacin was 0.01 g/mL, $MIC_{90}$ was 10> $\mu$g/mL. Three of the six strains were identified as Vibrio alginolyricus.