• Journal of Microbiology and Biotechnology
• /
• v.17 no.1
• /
• pp.146-153
• /
• 2007

A mathematical competition model between normal flora and an invading pathogen was devised to allow analysis of bacterial infections in a host. The normal flora includes the various microorganisms that live on or within the host and act as a primary human immune system. Despite the important role of the normal flora, no mathematical study has been undertaken on models of the interaction between it and invading pathogens against a background of antibiotic treatment. To quantify key elements of bacterial behavior in a host, pairs of nonlinear differential equations were used to describe three categories of human health conditions, namely, healthy, latent infection, and active infection. In addition, a cutoff value was proposed to represent the minimum population level required for survival. The recovery of normal flora after antibiotic treatment was also included in the simulation because of its relation to human health recovery. The significance of each simulation parameter for the bacterial growth model was investigated. The devised simulation showed that bacterial proliferation rate, carrying capacity, initial population levels, and competition intensity have a significant effect on bacterial behavior. Consequently, a model was established to describe competition between normal flora and an infiltrating pathogen. Unlike other population models, the recovery process described by the devised model can describe the human health recovery mechanism.

• Journal of Food Hygiene and Safety
• /
• v.12 no.1
• /
• pp.20-25
• /
• 1997

In order to investigate bacterial sanitary condition of fish and shellfish, we examined the normal flora in the 25 species of commercial fish and shellfish, and also proportional change of normal flora by storage period and temperature. Isolated 334 wereisolated in the normal fish and shellfish and predominant genera were Pseudomonas (25.2%), Staphylococcus(10%), Acinetobacter (7.2%), Vibrio (6.9%), Micrococcus (5.4%), Aeromonas (5.2%), and Enterobacter (5.2%). In accordance with storage period and temperature, Pseudomonas grew on high ratio at 1$0^{\circ}C$ steadily, but Proteus had increased proportionally at 2$0^{\circ}C$ and 3$0^{\circ}C$. Additionally, Yeast, and Micrococcus had decreased by period.

• Proceedings of the Korean Society for Language and Information Conference
• /
• 1995.02a
• /
• pp.103-108
• /
• 1995

• Korean Journal of Clinical Laboratory Science
• /
• v.41 no.2
• /
• pp.52-56
• /
• 2009

Arcanobacterium haemolyticum was usually isolated from respiratory infection. Occasionally, the cases were reported to cause pharyngotonsillitis, cellutitis, and abscess. A. haemolyticum is V form gram-positive bacilli (coryneform bacilli), which isoften considered to be non-pathogenic normal flora or contaminants in respiratory, skin and wound infection. In order to discriminate from normal flora, incubation for at least 48 hours is recommended. We describe a case that A. haemolyticum was isolated from cellulitis with group G ${\beta}$-hemolytic Streptococcus, Klebsiella pneumoniae ssp. pneumoniae, and Prevotella disiens.

• Animal Bioscience
• /
• v.37 no.7
• /
• pp.1263-1276
• /
• 2024

Objective: Pine needles are rich in many nutrients and exhibit antibacterial and antioxidant biological activities; however, the effects of different production methods of pine needle additives on the growth performance and intestinal flora of broiler chickens are not known. Methods: Normal diets were supplemented with pine needle fermentation juice (PNF), pine needle soaking juice (PNS), or pine needle powder (PNP), and the associated effects on growth performance, relative organ weights, intestinal development, intestinal histological morphology, intestinal flora, meat quality, and serum indicators in broiler chickens were observed. Results: The results showed that PNF, PNS, and PNP all significantly improved feed utilization and promoted the growth and development of broilers. All three additives also significantly improved the structure of the intestinal flora, specifically increasing the diversity of bacteria; increasing the abundance of beneficial bacteria, such as Faecalibacterium, Rikenella, and Blautia; and decreasing the abundance of harmful bacteria, such as Staphylococcus. The antioxidant properties of pine needles were also found to intensify lipid metabolic reactions in the blood, thus leading to lower triglycerides and total cholesterol. Meanwhile, high doses of PNF reduced jejunum and ileum weights and also increased meat yellowness. Lastly, none of PNF, PNS, or PNP had an effect on relative organ weights or intestinal histological morphology. Conclusion: The addition of pine needles to the diet of broiler chickens can effectively promote their growth performance as well as improve their intestinal flora and serum status without side effects; in particular, the dose of 0.2% of either PNF and PNS is expected to have the capacity to replace growth-promoting antibiotics as diet additives.

• Korean Journal of Microbiology
• /
• v.11 no.4
• /
• pp.175-180
• /
• 1973

This study was attempted to see more clear relationships among the enterobacteria, especially between the intestinal normal flora and pathogenic bacteria. It has been known that some intestinal normal flora produce the bactrial metabolites that are harmful to other enteric bacteria. One of the metabolites is known as colicin, the protein fraction, which possesses certain degree of inhibitory effect against other bacterial growth fraction, whih possesses certain degree of inhibitory effect against other bacterial growth. As a preliminary study for a colicin purification, the antagonistic effect of E, coli to groups of Salmonella and Shigella has been studied by means of in vitro quantitative culture method. 1. E.coli showed definite inhibitory effects aganist both Salmonella and Shigella groups in the mixture of two organisms. 2. The inhibitory effects of E.coli in the E.coli-Salmonella and the E.coli-Shigella mixture occurred from 4 hours incubation following the inoculation. 3. Even the complete inhibition of pathogenic enteric bacterial growth was noticed in the E.coli-Salmonella mixture at overnight incubation. 4. Among the diluted mixtures, 1:100, 1:1,000, and 1:10,000, survival rate of pathogenic enteric bacteria in the mixtures with E.coli showed least affected at the 1:1,000 dilution. 5. It was found that the antagonistic effect aganist groups of Salmonella-shigella was depending upon the groups of the genera.

• Journal of the Korean Society of Environmental Restoration Technology
• /
• v.7 no.1
• /
• pp.10-18
• /
• 2004

The urban ecosystem, unlike the natural ecosystem, has been affected by the urban environment, so the existences of normal creatures have been threatened and eventually the stability has declined to consist of those that have adapted to such. Therefore, by creating a list of such organisms, their number of variety can be found out and their ecological distinction can be understood. Because flora is known to be an ecological index reflecting region's effects of human and societal environments, weather, and climates, it is a useful method of finding out the ecological position and distinctiveness of that region. The study site is part of watershed at Yangjae Stream, Kahngnam-ku, Seoul. In this study, the difference of flora in each land use type are investigated by plant identification. The purpose of this study is to evaluate the city's plant surviving environment, and eventually to contribute to the restoration of urban green spaces by finding out the plants which are appropriate for the corresponding environment. After doing the study, it was found that the urban forest is the most stable urban ecosystem while the urban park is seriously disturbed, and ecologically unstable. The urban stream is also disturbed continuously.

• Korean Journal of Veterinary Research
• /
• v.38 no.1
• /
• pp.217-225
• /
• 1998

영국 Hertfordshire의 두지역에서 사육되고 있는 건강한 조랑말의 결막낭내 상존하고 있는 진균총의 분포도를 조사 비교하고자 36두 조랑말의 양안(총72안)의 상 하 결막낭에서 시료를 채취하여 진균을 분리 동정하였다. 총 76.4%의 안구에서 진균이 발견되었으며, 13종이 분리되었다. 전체적으로 가장 많이 분리된 진균은 Aspergillus spp(27.8%), Nocardia spp(25.0%), Cladosporium spp(19.4%), Penicillium spp(9.7%) 및 Penicillium spp(9.7%)순이었다. 1지역에서는 Nocardia spp와 Cladosporium spp가 가장 많이 분리된 반면, 2지역에서는 Aspergillus spp가 가장 많이 분리되었다. 상 하결막낭내 진균분리율의 차이는 상결막낭에서보다는 하결막낭내에서 진균이 유의성 있게 많이 분리되었다(p<0.05). 시료채취시에 사용된 swab의 상태에 따른 비교에서 건조된 swab과 젖은 swab간에는 통계적 유의성이 없었다.

• Journal of Nutrition and Health
• /
• v.32 no.2
• /
• pp.129-136
• /
• 1999

This study was conducted to investigate the effect of fructooligosaccharide on intestinal flora, lipid metabolism and immune response. Thirty two male rats of Sprague-Dawley strain were divided into two groups according to body weight. Each group was fed the diet containing 2% cholesterol or the normal diet, respectively for 4 weeks. Each group was again divided into two sub-groups and they were fed with the diet containing 5% of sucrose and fructooligosaccharide, respectively for 8 weeks. The number of bifidobacteria slight increased, but not significantly, in oligosaccharide groups. Plasma total lipid concentration in cholesterol group was signficantly increased compared to the value in normal group. Dietary oligosaccharide decreased plasma total lipid concentration and triglyceride concentrations in normal group, but not in cholesterol group. Fecal lipid excretion was higher in cholesterol group than in normal group. Fecal cholesterol concentration in cholesterol-oligosaccharide group was significantly increased compared to other groups. Cholesterol had slight effects on TBARS and the immune status, but dietary oligosaccharide had no effects on these variables. The results in this study suggest that dietary oligosaccharide had no effect on serum and liver profiles of rats fed high cholesterol diet but increases the fecal cholesterol excretion.

• Pediatric Gastroenterology, Hepatology & Nutrition
• /
• v.9 no.2
• /
• pp.162-168
• /
• 2006

Purpose: Microbial colonization of the intestine begins just after birth and development of the normal flora is a gradual process. The first bacteria colonizing the intestine in newborns are Staphylococcus, Enterobacteriaceae and Streptococcus. For several days after birth, the number of Bifidobacterium spp. increase. The aim of this study was to investigate the changes of microflora for seven days postnatally in neonatal stool. Methods: Fifteen neonates (breast : formula : mixed feeding 1 : 8 : 6, vaginal delivery : cesarean section 3 : 12) who were born at the Kangdong Sacred Heart Hospital, Hallym University were enrolled. First meconium and stools of postnatal 1-, 3-, and 7-day were innoculated. Blood agar plates for total aerobes, trypton bile X-glucuronide agar for E. coli, phenylethyl alcohol agar for gram positive anaerobes, MRS agar for Lactobacillus spp., bifidobacterium selective agar for Bifidobacterium spp. and cefoxitin-cycloserine-fructose agar for Clostridium difficile were used in the general incubator ($CO_2$ free incubator), $CO_2$ incubator or the anaerobic chamber for 48 or 72 hours at $37^{\circ}C$ and then colony forming units were counted. Results: No microflora was identified in the first meconium. Total aerobes, E. coli, and gram positive anaerobes were significantly increased with advancing postnatal days. In only one baby, Lactobacillus acidophilus was detected $2{\times}10^5CFU/g$ in the seven-day stool. Bifidobacterium spp. was detected in two babies. Clostridium difficile was not detected during the seven days. There were no significant differences in the bowel flora depending on the delivery pattern and feeding method. Conclusion: This study shows many changes in the intestinal normal flora in neonatal stool during seven days postnatally. If these findings are confirmed with larger studies, the data may be preliminary findings to support use of probiotics in neonates.