No Abstract Available.
Cytotoxins* ; Gram-Positive Bacteria* ; Perforin*

No Abstract Available.
Cytotoxins* ; Gram-Positive Bacteria* ; Perforin*

In order to evaluate contamination of the topical eye drugs, 112(36 kinds) medications used over 1 month by the patients and 80(25 kinds) medications used at OPD(outpatient department) were studied by culturing the caps, the tips and the contents. Coagulase-negative staphylococcus was mainly isolated from the caps and the tips(p<0.05). But the other gram-positive bacteria, gram-negative bacteria and fungi were isolated from all medication sites. The most frequent site of contamination was the tips of the medications. Frequency of contamination based on detail of medications and preservatives of medications was not statistically significant(p>0.05). The medications used by the patients for a long time in comparison with the medications used at OPD were significantly more likely to be contaminated(p<0.0001). Therefore, we think that the topical eye durgs should be used with proper instillation and storage for a short period because of increase risk of contamination.
Fungi ; Gram-Negative Bacteria ; Gram-Positive Bacteria ; Humans ; Staphylococcus

Quorum sensing (QS) plays a major role in the outbreak mechanism of foodborne diseases caused by food poisoning and food spoilage. QS affects the formation of cell membrane and pathogenicity ofpathogenic bacteria. Through the in-depth understanding of QS molecules of food-borne pathogens, we describe here the types of signal molecules produced by Gram-negative and Gram-positive bacteria, and the differences in QS molecules. Meanwhile, we introduce the detection of QS molecules by different technologies. According to the influence of QS on food, we propose also future research needs for the control of foodborne pathogenic bacteria.
Gram-Negative Bacteria ; Gram-Positive Bacteria ; Quorum Sensing

BACKGROUND: Although most of aerobic gram-positive bacilli have been considered to be contaminants, gram-positive bacilli should be identified to the species level if they are isolated from sterile body sites such as blood, and from adequately collected clinical specimens if they are the predominant organisms. However, identification of gram-positive bacilli are difficult due to the enormous diversity of these organisms and the small number of readily available commercial identification systems in clinical laboratories. Gram-positive bacilli and coccorods isolated from blood cultures were tested with BBL Crystal Gram-Positive (GP) Identification (ID) system in order to evaluate the system's usefulness of identifying these bacteria. METHODS: Thirty-seven stock strains of aerobic gram-positive bacteria isolated from blood cultures between October 1998 and November 1999 at Wonju Christian Hospital were simultaneously tested by BBL Crystal GP ID system and API system. Three kinds of API system (API Coryne, API 50 CHB, and API 20 Strep) were tested according to gram stain results. Gram-positive bacilli or gram-positive coccorods consecutively isolated from blood cultures from May to November in 2000 were identified by BBL Crystal GP ID system. RESULTS: Among the 37 stock strains of aerobic gram-positive bacteria, agreement rate of identification between Crystal GP ID system and API system were 88% to the genus level and 63% to the species level in Bacillus species, and 90% to the genus level in Corynebacterium species. The isolation rate of gram-positive bacteria from blood cultures from May to November in 2000 to the genus level were: Bacillus; 41.9%(18/43), Corynebacterium; 37.2%(16/43), and the other grampositive coccorods; 20.9%(9/43). CONCLUSIONS: Crystal GP ID system is a useful identification system which, when combined with basic microbiological tests, should lead to satisfactory identification results for gram-positive bacteria isolated from blood cultures.
Bacillus ; Bacteria ; Corynebacterium ; Gangwon-do ; Gram-Positive Bacteria*

Antibacterial activity of EA, a preparation of water soluble components made from carpophores of Elfvingia applanata (Pers.) Karst, was examined by macrobroth diltution method against a number of bacterial species. Antibacterial effects of EA were expressed as minimal inhibitory concentration (MIC) for growth. Among twelve species of bacteria tested, six strains of each gram positive bacteria and gram negative bacteria, EA showed the most potent antibacterial activity against Staphylococcus epidermidis and Proteus vulgaris, of which MICs were 1.25 mg/ml of EA. To investigate the antibacterial effects of combinations of EA with third generation cepholosporins, such as cefotaxime, ceftriaxone, ceftazidime, and cefixime, the fractional inhibitory concentration (FIC) and fractional inhibitory concentration index (FICI) were determined by macrodilution checkerboard assay for twelve bacterial strains. Combinations of EA and third generation cephalosporins exhibited either additive or indifferent effects in most instances. However, synergistic effects were observed in six instances. No antagonistic effect was observed in any cases.
Bacteria ; Cefixime ; Cefotaxime ; Ceftazidime ; Ceftriaxone ; Cephalosporins* ; Gram-Negative Bacteria ; Gram-Positive Bacteria ; Proteus vulgaris ; Staphylococcus epidermidis

Extracellular vesicles (EVs), also known as membrane vesicles, are vesicular bodies secreted by eukaryotic cells and bacteria. EVs can carry proteins, DNA, RNA, and various metabolites for the exchange and transmission of substances between cells. They play contents-dependent physiological functions, such as delivering nutrients, participating in immune response, and treating cancers. Currently, most studies focus on the exploration of vesicles secreted by eukaryotic cells and gram-negative bacteria, while few studies focus on gram-positive bacteria. This review summarized the production, content composition, physiological function, and engineering of EVs secreted by gram-positive bacteria, and prospected future perspectives in this area.
Bacteria/metabolism* ; Extracellular Vesicles/metabolism* ; Gram-Negative Bacteria ; Gram-Positive Bacteria/metabolism* ; Proteins/metabolism*

BACKGROUND: To access the clinical usefulness of MicroScan(R) Synergies plus Combo Panels (Siemens, USA) for the identification and antimicrobial susceptibility test (AST) of Gram-negative bacteria (GNB) and Gram-positive cocci (GPC), we compared MicroScan(R) Synergies plus Combo Panels with MicroScan(R) conventional Combo Panels. METHODS: One-hundred four isolates of GNB were simultaneously tested with MicroScan(R) Synergies plus Neg Combo Type 2 Panel (SINC2) and MicroScan(R) Neg Combo Panel Type 44 (NC44). One-hundred isolates of GPC were simultaneously tested with MicroScan(R) Synergies plus Pos Combo 3 Panel (SIPC3) and MicroScan(R) Pos Combo 1A (PC1A). RESULTS: Of the GNB isolates, agreement rate of identification between SINC2 and NC44 were 92.3% to the species level and 93.3% to the genus level. Of the GPC isolates, agreement rate of identification between SIPC3 and PC1A were 85.0% to the species level and 100% to the genus level. Of the GNB isolates, agreement rate of AST according to antimicrobial agents between SINC2 and NC44 ranged from 86.5% to 100%. Among GPC isolates, agreement rate of AST according to antimicrobial agents between SIPC3 and PC1A were higher than 96.0% with the exception of gentamicin and quinupristin-dalfopristin. CONCLUSION: Compared with MicroScan(R) conventional Combo Panels (NC44, PC1A), MicroScan(R) Synergies plus Combo Panels (SINC2, SIPC3) showed high agreement rate of identification and AST, and had the advantage of more rapid reporting.
Anti-Infective Agents ; Gentamicins ; Gram-Negative Bacteria ; Gram-Positive Bacteria ; Gram-Positive Cocci ; Imidazoles ; Nitro Compounds ; Virginiamycin

The production of extracellular vesicles is a ubiquitous process in both Gram-negative and Gram-positive bacteria. Gram-negative bacteria produce and secrete outer membrane vesicles during in vitro culture and in vivo infection and their contribution to bacterial pathogenesis has been well characterized. However, little is known about extracellular vesicles in Gram-positive bacteria. Until now, only few Gram-positive bacterial species, Staphylococcus aureus, Bacillus anthracis, B. cereus, and B. subtilis, have been found to produce membrane vesicles (MVs), but their contribution to bacterial pathogenesis has not been understood. Here, I discuss S. aureus MVs in terms of MV production, interaction of MVs with host cells, and immune response against MVs to understand its potential role in S. aureus pathogenesis.
Bacillus anthracis ; Gram-Negative Bacteria ; Gram-Positive Bacteria ; Membranes ; Proteome ; Staphylococcus ; Staphylococcus aureus

OBJECTIVE: To investigate the clinical characteristics, etiology and drug susceptibility of bacterial bloodstream infections in acute leukemia(AL) patients. METHODS: Clinical data, etiology and drug susceptibility of acute leukemia patients with bacterial bloodstream infections from April 2009 to April 2018 were retrospectively analyzed. RESULTS: A total of 376 strains were isolated, 76.9% was Gram-negative bacterial and 23.1% was Gram-positive bacteria. Escherichia coli, Pseudomonas aeruginosa and Klebsiella pneumoniae were listed as the top three of Gram-negative bacteria. The susceptibility of Escherichia coli to the tigacycline, imipenem and meropenem was 100.0%, 98.2% and 98.1%, respectively. The susceptibility of Klebsiella pneumoniae to the tigacycline, imipenem and meropenem were 100.0%, 98.3% and 94.4%, respectively. The adjustment rate for initial use of carbopenems was 3.8%, while the adjustment rate for initial use of noncarbopenems was 74.3% in patients with main Gram-negative bacterial blood stream infection. The susceptibility of Gram-positive bacteria to glycopeptide antibiotics, linezolid and tigacycline was 100.0%. CONCLUSION Gram-negative bacteria is the majority type of bacteria in AL patients with bacteria blood stream infections. The susceptibility of Gram-negative bacteria to the carbapenems is high, and the treatment adjustment rate is obviously low. The glycopeptide, linezolid and tigacycline are effective for Gram-positive bacteria infections..
Bacteremia ; Gram-Negative Bacteria ; Gram-Positive Bacteria ; Humans ; Microbial Sensitivity Tests ; Retrospective Studies