• Journal of Korean Academy of Nursing
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• v.9 no.2
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• pp.17-26
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• 1979

This research is to prevent the infection of maternity in the hospital by examining the microbes contaminations in maternity through airbone microbes and those who are engaged in the ward of O.B. ＆ G.Y. and to furnish the basic data available to hospital management. The bacterial growth of airbone microbes contaminations in nosocomial air and who thor the nasal cavity of passers by (doctors, nurses, parturient women) who went to the ward of O.B. ＆ G.Y. contaminated or not were examined in“E”Univ. Hospital from July to August, 1979 by using thioglycollate broths and agar plates. The following results were obtained: 1. The average colony number of airborne microbes revealed as follows the pediatric ward (36 colonies), the internal ward (33 colonies), the ward of O.B. ＆ G.Y. (30 colonies), the ward of surgery (24 colonies), delivery-waiting room (11 colonies), and the delivery room (3 colonies). 2. The bacterial growth beforenoon differed from that of afternoon. Namely, the latter (24 colonies) was higher than the former (21 colonies). 3. The type of strains isolated from the air of the ward revealed staphylococci (82%), Gram negative bacilli (18%), fungi (17%), Gram positive diplococci (13%), and Bacillus subtilis (2.8%). 4. The strains isolated in the delivery-waiting room revealed staphylococci (66.7%), Gram negative bacilli (33.6%), and revealed staphylococci (75%), Gram positive diplococci (8.3%), and fungi (8.3%), in delivery room. 5. Most of strains isolated in the ward of O.B. & G.Y. revealed staphylococci (100.0%), Gram positive diplococci (8.3%), and Gram negative bacilli (6.7%). 6. The strain isolated in the surgical ward revealed staphylococci (91.7%), fungi (33.3%), Gram positive diplococci (25%), Gram negative bacilli (25%) and Bacillus subtilis (8.3%). 7. The strain isolated in the pediatric ward revealed staphylococci (75%), fungi (25%), Gram positive diplococci (8.3%), Bacillus subtilis (8.3%), and Gram negative bacilli (8.3%). 8. The strain isolated in the internal ward revealed staphylococci (91.7%), fungi (33.3%), Gram positive diplococci (25%), and negative bacilli (16.7%). The strains isolated from the nasal cavity of those doctors and nurses who and enaged in the ward of O.B. & G.Y. revealed staphylococci (80%), Bacillus subtilis (10%), and Gram negative bacilli (10%), from doctors and Gram positive diplococci (10%), instead of Gram negative bacilli (10％), from nurses. 10. The strain isolated from nasal cavity of parturient women on admission revealed staphylococci (90%), and Gram negative bacilli (10%), but after admission revealed staphylococci (70％), Gram positive diplococci (10%), and Gram negative bacilli (10%). 11. Of the total 91 staphylococci isolated from the air of the ward, the Coagulase pastive was 36 (39.6%), and the negative 55 (60.4%), As a result of the coagulase experiment of the staphylococci isolated from the nasal cavity of those who are engaged in the ward of O.B. ＆ G.Y. all were revealed as negative that belonged to non-pathogenic. 12. Consequence of the biochemic examination of the gram negative bacilli isolated from the air of the ward the aerobacter aerogens revealed was (16.7%) E-coli 5％ in the nasal cavity of those came and went to the of O.B. ＆ G.Y. and Aerobacter aerogens 7.5%.

• Bulletin of the Korean Chemical Society
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• v.34 no.11
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• pp.3261-3264
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• 2013

Carbon nanocomposites composed of carbon nanostructures and metal nanoparticles have become one of useful materials for various applications. Here we present the preparation and antibacterial activity of CNT-Ag and GO-Ag nanocomposites. Their physical properties were characterized by TEM, XPS, and Raman measurements, revealing that size-similar and quasi-spherical Ag nanoparticles were anchored to the surface of the CNT and GO. The antibacterial activities of CNT-Ag and GO-Ag were investigated using the growth curve method and minimal inhibitory concentrations against Gram-negative and Gram-positive bacteria. The antibacterial activities of the carbon nanocomposites were slightly different against Gram-positive and Gram-negative bacteria. The proposed mechanism was discussed.

• Korean Journal of Microbiology
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• v.26 no.1
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• pp.60-66
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• 1988

Dynamics of bacterial communities and its colonization under aerobic gemp retting were observed in air lift fermentor as a closed system, unlike conventional hemp retting as an open system. Dried hemp which was harvested in both 1986 and 1987 was retted at room temperature. Predominant community was facultatively anaerobic Gram-negative rods, and its density was increased from $3.0\times 10^{7}$ cells/ml to $9.0\times 10^{8}$ cells/ml. The density of facultatively nanerobic Gram-positive fods was maintained at the lovel of $5.0\times 10^{6}$ cells/m, and this Gram-positive bacterial community was not participated in retting. In the Gram-negative bacterial community during the retting, five types of colonieswere developed at early stage of pH7.0-8.0, and thereafter, only three types were colonized till later stage, shich were identified as pectolytic strain Erwinia salicis, Erwinia tracheiphila and Enterobacter agglomerans. A community of facultatively Gram-negative rods was mainly proliferated in stems and dispersed into liquor after 6-8 hours. Retting was terminated within 70-80 hours.

• Journal of Microbiology and Biotechnology
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• v.29 no.1
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• pp.1-10
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• 2019

Gram-negative pathogens, such as Klebsiella pneumoniae, Pseudomonas aeruginosa, and Acinetobacter baumannii, pose a serious threat to public health worldwide, due to high rates of antibiotic resistance and the lack of development of novel antimicrobial agents targeting Gram-negative bacteria. The outer membrane (OM) of Gram-negative bacteria is a unique architecture that acts as a potent permeability barrier against toxic molecules, such as antibiotics. The OM is composed of phospholipids, lipopolysaccharide (LPS), outer membrane ${\beta}-barrel$ proteins (OMP), and lipoproteins. These components are synthesized in the cytoplasm or in the inner membrane, and are then selectively transported to the OM by the specific transport machines, including the Lol, BAM, and Lpt pathways. In this review, we summarize recent studies on the assembly systems of OM components and analyze studies for the development of inhibitors that target these systems. These analyses show that OM assembly machines have the potential to be a novel attractive drug target of Gram-negative bacteria.

• 한국해양학회지
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• v.24 no.3
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• pp.148-156
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• 1989

This investigation was performed in eutrophic lake within the framework of a series of studies to evaluate the significance of gram reaction for both bacterioplankton and attached bacteria in the dynamics of organic materials at various aquatic ecosystems. In Lake Kasumigaura as a representative of the highly eutrophic freshwater environments, the gram-stain characteristics of the bacterial community changed with the influx of pulses of phytoplankton, as those in the meso trophic environments. The predominency of the gram-negative forms in the bacterial community was about 57% for bacterioplankton and about 53% for attached bacteria. The statistical analysis of the difference of these two distributions showed that these communites were different. Both gram-negative and gram-positive bacteria attached to particles were shown to effect the formation and degradation of particulate organic matter. Gram-negative bacteria plankton participate exclusively in the dynamics of dissolved organic matter.

• Journal of Life Science
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• v.9 no.3
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• pp.314-327
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• 1999

This study was investigated to isolate identify the total bacteria and fungi from the indoor air of work-place of the shoes, paint, stainless steel, and plastic industries. The number of bacterial colonies on the nutrient agar plates were calculated by the open petridish method for 30 minutes in indoor air of work-places at the autumn and winter. The isolated bacteria were identified by Gram stain and biochemical test using API Staph and API 20E kits. The isolated fungal colonies were identified by gross appearance of the giant colonies and microscopic examination of their spore and hyphal characteristics on the slide culture method. The minimum inhibitory concentration (MIC) of several antibiotics against isolated bacteria was determined by the microdilution method with Mueller-Hinton broth. The 70-400 colonies in autumn and 54-236 colonies in winter were isolated from the indoor air of work-places of several industry. The isolation rates of Gram positive cocci, Gram positive bacilli, Gram negative bacilli, and Gram negative cocci were 46.3%, 19.8%, 17.3%, and 16.1%, respectively. In Gram positive cocci, the most strains were identified as Aerococcus spp, Micrococcus spp, and Staphylococcus spp. In Gram positive and negative bacilli, and Gram negative cocci were identified as Bacillus spp, Pseudomonas spp, and Neisseria spp, respectively. The frequently isolated fungi were Aspergillus spp, Penicillium spp and Rhizopus spp, respectively. The frequently isolated Aerococcus spp, Micrococcus spp, and Staphylococus spp were highly resistance against ampicillin, erythromycin, methicillin, and tetracycline. These results arouse our attention to microbiologic pollution in the indoor air of work-places of industries.

• Korean Journal of Veterinary Research
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• v.19 no.2
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• pp.131-134
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• 1979

In order to know the main causative agent and distribution of the agents in Gram-negative bacillus infections of bovine udders, one hundred and forty-eight cultures of Gram-negative bacilli isolated from clinical cases of mastitis during lactation over a period of 2 years in 6 herds of 180 Holstein cows were studied. Escherichia coli occupied 54.7% of the isolates was the most frequently isolated Gram-negative bacillus. 30 of the isolates (20.3%) were Enterobacter aerogenes, but Enterobacter cloacae was not isolated. Remaining isolates were Klebsiella pneumoniae, Proteus spp., Preudomonas aeruginosa and Alcaligenes faecalis. Most of the isolates (75.0%) were isolated from rear quarters.

• Biotechnology and Bioprocess Engineering:BBE
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• v.11 no.4
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• pp.288-292
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• 2006

Through statistically designed experiments, lysis agents were optimized to effectively disrupt bacterial cells in a microfluidic device. Most surfactants caused the efficient lysis of Gram-positive microbes, but not of Gram-negative bacteria. A Plackett-Burman design was used to select the components that increase the efficiency of the lysis of the Gram-negative bacteria Escherichia coli. Using this experimental design, both lysozyme and benzalkonium chloride were shown to significantly increase the cell lysis efficiency, and ATP was extracted in proportion to the lysis efficiency. Benzalkonium chloride affected the cell membrane physically, while lysozyme destroyed the cell wall, and the amount of ATP extracted increased through the synergistic interaction of these two components. The two-factor response-surface design method was used to determine the optimum concentrations of lysozyme and benzalkonium chloride, which were found to be 202 and 99 ppm, respectively. The lysis effect was further verified by microscopic observations in the microchannels. These results indicate that Gram-negative cells can be lysed efficiently in a microfluidic device, thereby allowing the rapid detection of bacterial cells using a bioluminescence-based assay of the released ATP.

• Journal of Veterinary Clinics
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• v.21 no.2
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• pp.133-139
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• 2004

Bacterial pathogens were isolated from 36 dogs with respiratory signs, that were submitted to Veterinary Clinics in Jeju, including Veterinary Medical Teaching Hospital in Cheju National University. Of 36 isolates, 16 (44.4%) bacterial pathogens were Gram-positive and 20 (55.6%) were Gram-negative. Gram-positive bacteria identified with API Staph were 12 S. intermedius (33.3%), 2 S. aureus (5.6%), 1 S. haemolyticum (2.8%), and 1 S. xylosus (2.8%). Gram-negative organisms identified with API 20E or API NE included 8 Bordetella bronchiseptica (22.2%), 6 Escherichia coli (16.7%), 4 Pasteurella spp. (11.1%), 1 Enterobacter intermedius (2.8%), and 1 Oligella ureolytica (2.8%). Both Staphylococcus spp. isolates and Gram-negative pathogens were resistant to one or more antibiotics, including ampicillin (AM), amoxicillin/clavulanic acid (AMC), chloramphenicol (C), cefazolin (CZ), erythromycin (E), gentamicin (GM), kanamycin (K), lincomycin (L), oxacillin (OX), trimethoprim/sulfamethoxazole (SXT), and tetracycline (TE). All Staphylococcus spp. were susceptible to AMC, OX and VA, while many isolates were highly resistant to L (87.5%), E (68.8%), P (62.5%), and AM (56.3%). Antibiotic-resistant patterns of staphylococcal isolates were shown ranges from single to 9-resistant patterns. Resistant rates to antibiotics of Gram-negative bacteria were usually higher than those of Staphylococcus spp. in this study. Most Gram-negative bacteria were highly resistant to L (90.0%), AM (85.0%), E (85.0%), P (85.0%), OX (80.0%), and CZ (75.0%). B. bronchiseptica isolates showed 5 to 8 antibiotics-resistant patterns and Pasteurella spp., 2 to 8-resistant patterns. In particular, all 6 E. coli isolates were resistant to more than 9 different kinds of antibiotics, including one strain resistant to all antibiotics tested.

• Journal of Yeungnam Medical Science
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• v.10 no.1
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• pp.28-36
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• 1993

Major pathogenic Gram-negative organisms such as P. aeruginosa, Serratia species, E. coli, Enterobacter species which are isolated from the specimens in large medical centers are greatly resistant to the commonly used antibiotics. Gram-negative bacilli, which had been isolated in Yeungnam University Hospital during the period from December 1992 to April 1993 and turned out to be resistant to the primary antibiotics susceptibility test for chloramphenicol, ampicillin, cephalothin, gentamicin, tetracyclin, amikin and tobramycin, were subjected to the secondary antibiotics susceptibility test for aztreonam, ceftazidime, ciprofioxacine, cefotaxime, cefamandole, piperacillin, ticarcillin and sulfamethoxazole trimethopime. Out of 315 tested organisms, 167 organisms(53%) were resistant to all secondary antibiotics in vitro. Antimicrobial activity of ceftazidime(37.1%), aztreonam(11.%), ciprofioxacine(7.9%) against Gram negative bacilli were slightly more active than other antibiotics tested, while cefamandole was not active to all the Gram-negative bacilli tested. According to the specimens, E. coli was the most frequently resistant organisms to the primary antibiotics from urine, A. baumanii, from respiratory system and wounds, and P. aeruginosa from various specimens. In summary, Gram negative bacilli resistant to the primarily applied antibiotics also were resistant to the secondary antibiotics. Rearrangement of the antibiotics disks for the antibiotic susceptibility test should be considered.