scholarly journals THE ANTIBACTERIAL ACTIVITY OF HEMOGLOBIN

1958 ◽  
Vol 107 (2) ◽  
pp. 167-183 ◽  
Author(s):  
Derek Hobson ◽  
James G. Hirsch
Keyword(s):  
Bactericidal Activity ◽  
Lethal Effect ◽  
Bactericidal Effect ◽  
Mineral Acid ◽  
Ionic Concentration ◽  
Coliform Bacteria ◽  
Bactericidal Action ◽  
Lethal Action ◽  
Serum Fractions

Low concentrations of hemoglobin (0.1 µg./ml. or less) exert a lethal action on some Gram-negative bacteria under certain conditions in vitro. Hemoglobins from various mammals and the distinct genetic types of human hemoglobin all manifest similar bactericidal activity. The bactericidal effect is a function of the globin moiety of the molecule; native and acid or acid-alcohol denatured globins have the same degree of activity. Hemoglobins kill enterobacteriaceae only under precisely controlled conditions. The test medium must be low in ionic concentration and acid in reaction. Various strains of Escherichia and Salmonella are susceptible to the lethal effect of hemoglobin, while the few strains of Shigella, Klebsiella, and Proteus examined were resistant. Certain acid polysaccharides and basic amines or proteins block the bactericidal effect when incorporated in the test in low concentration. Present evidence also suggests that exposure of the microorganisms to certain cations such as magnesium renders them resistant to the lethal action of globin. Hemoglobin loses its bactericidal power when complexed with haptoglobin, and serum fractions rich in free haptoglobin protect otherwise susceptible bacteria from killing by hemoglobin. The reaction appears to be a bactericidal rather than a bacteriostatic one. At 38°C. maximal killing requires approximately 30 minutes; at temperatures of 28°C. or 0°C. the bactericidal action does not take place. The minimal concentration of hemoglobin required to kill 50 per cent of the microorganisms in the test is unrelated to the size of the bacterial inoculum. Under conditions suitable for bactericidal action, hemoglobin is adsorbed onto heat-killed susceptible strains of coliform bacteria; material possessing bactericidal activity can be eluted with dilute mineral acid.

scholarly journals BACTERICIDAL ACTION OF HISTONE

1958 ◽  
Vol 108 (6) ◽  
pp. 925-944 ◽  
Author(s):  
James G. Hirsch
Keyword(s):  
Bactericidal Activity ◽  
Physiological State ◽  
Lethal Effect ◽  
Test System ◽  
Morphological Alteration ◽  
Rabbit Serum ◽  
E Coli ◽  
Lethal Action ◽  
K 12

The arginine-rich fraction of calf thymus histone (histone B) exerts bactericidal activity on various coliform bacilli and micrococci under certain conditions in vitro. Final concentrations of less than 1 µg. histone per ml. kill susceptible microbes without detectable morphological alteration or lysis. Among the microorganisms highly susceptible to histone are Escherichia, Salmonella, Shigella, Pseudomonas, Klebsiella, and Micrococcus pyogenes var. albus. Less susceptible or completely resistant are Proteus, Serratia, Micrococcus pyogenes var. aureus, and various types of hemolytic streptococci. Coliforms grown on solid media are much more resistant to the lethal effect of histone than are those cultured in liquid media. This difference is apparently related to the physiological state of the bacteria; agar grown microorganisms washed with water remain resistant to histone, whereas incubation in broth rapidly renders them more susceptible. Histone is adsorbed onto heat-killed E. coli K-12 under conditions suitable for lethal action on this organism. The bactericidal activity of histone is but little affected by pH of the test system, but ionic strength of the medium exerts a marked influence, the lethal action being reduced or blocked as the salt concentration reaches levels higher than that of 0.15–0.2 M NaCl. Relatively high concentrations of rabbit serum or of bovine plasma albumin reduce the bactericidal activity of histone in a medium at pH 7; these serum preparations are, however, essentially without effect in the test system at pH 5.6. The bactericidal effect of histone is antagonized by addition to the medium of small amounts of certain basic substances (protamine, spermine), or of various acid polysaccharides (heparin, nucleic acid, bacterial lipopolysaccharides). The rate of killing of E. coli K-12 by histone increases as the temperature and the concentration of histone are raised. Within the limits studied, this rate also appears to be directly proportional to the concentration of bacteria in the system.

scholarly journals Bactericidal Activity of Octenidine to Various Genospecies of Borrelia burgdorferi, Sensu Lato Spirochetes in Vitro and in Vivo

2017 ◽  
Vol 66 (2) ◽  
pp. 259-263 ◽  
Author(s):  
Stanisława Tylewska-Wierzbanowska ◽  
Urszula Roguska ◽  
Grażyna Lewandowska ◽  
Tomasz Chmielewski
Keyword(s):  
Borrelia Burgdorferi ◽  
Bactericidal Activity ◽  
Reliable Method ◽  
Bactericidal Effect ◽  
Sensu Stricto ◽  
Borrelia Burgdorferi Sensu Lato ◽  
Bactericidal Action ◽  
Speed Up

The aim of our studies was to invent a reliable method for detection of bactericidal activity of disinfectants against Borrelia burgdorferi in suspension (in vitro) and in cell line cultures (in vivo). In the suspension method, 0.01 % octenidine at 20°C and 35°C was bactericidal to Borrelia afzeli; Borrelia garini, B. burgdorferi sensu stricto after 5 minutes treatment. Increase of the temperature to 35°C speed up the bactericidal effect to 1 minute. The bactericidal action of octenidine towards B. burgdorferi spirochetes growing in fibroblasts was less effective and needed a longer time to kill them than in the suspension.

scholarly journals THE BACTERICIDAL ACTION OF PROPYLENE GLYCOL VAPOR ON MICROORGANISMS SUSPENDED IN AIR. I

1942 ◽  
Vol 75 (6) ◽  
pp. 593-610 ◽  
Author(s):  
O. H. Robertson ◽  
Edward Bigg ◽  
Theodore T. Puck ◽  
Benjamin F. Miller ◽  
Keyword(s):  
Influenza Virus ◽  
Propylene Glycol ◽  
Marked Reduction ◽  
Bactericidal Effect ◽  
Bactericidal Action ◽  
Lethal Action ◽  
Droplet Form ◽  
Bactericidal Properties ◽  
Enclosed Space

It has been found that propylene glycol vapor dispersed into the air of an enclosed space produces a marked and rapid bactericidal effect on microorganisms introduced into such an atmosphere in droplet form. Concentrations of 1 gm. of propylene glycol vapor in two to four million cc. of air produced immediate and complete sterilization of air into which pneumococci, streptococci, staphylococci, H. influenzae, and other microorganisms as well as influenza virus had been sprayed. With lesser concentrations of propylene glycol, rapid and marked reduction in the number of air-borne bacteria occurred, but complete sterilization of the air required a certain interval of time. Pronounced effects on both pneumococci and hemolytic streptococci were observed when concentrations as low as 1 gm. of glycol to fifty million cc. of air were employed. Numerous control tests showed that failure of the glycol-treated microorganisms to grow on the agar plates was due to actual death of the bacteria. The means by which propylene glycol vapor produces its effect on droplet-borne bacteria is discussed and data relating the bactericidal properties of propylene glycol in vitro to the lethal action of its vapor is presented. Atmospheres containing propylene glycol vapor are invisible, odorless, and non-irritating. This glycol is essentially non-toxic when given orally and intravenously. Tests on possible deleterious effects of breathing propylene glycol containing atmospheres over long periods of time are being carried out.

scholarly journals FURTHER STUDIES ON PREPARATION AND PROPERTIES OF PHAGOCYTIN

1960 ◽  
Vol 111 (3) ◽  
pp. 323-337 ◽  
Author(s):  
James G. Hirsch
Keyword(s):  
Citric Acid ◽  
Ionic Strength ◽  
Lethal Effect ◽  
Coliform Bacteria ◽  
Polymorphonuclear Leucocytes ◽  
In Vitro Test ◽  
Bactericidal Action ◽  
Gram Positive ◽  
Trichloracetic Acid

Phagocytin and histone differ significantly in the following regards: (a) the bactericidal action of histone is rapidly lost on peptic digestion, while that of phagocytin is but little affected; (b) the lethal effect of phagocytin on coliform bacteria is much more resistant than that of histone to antagonism by spermine or by increasing ionic strength of the medium; (c) phagocytin can be extracted from disrupted granulocytes with dilute citric acid whereas effective extraction of histone requires stronger mineral acid or strong salt solution; (d) phagocytin is limited in distribution to polymorphonuclear leucocytes while histone is demonstrable in many tissues. A new technique has been devised which permits extraction of phagocytin essentially free of lysozyme and histones. Phagocytin thus prepared kills certain Gram-positive bacteria as well as Gram-negative bacilli under appropriate in vitro test conditions. Among susceptible Gram-positive microbes are Group A streptococci and staphylococci. Phagocytin is demonstrable in citric acid extracts of granulocytes obtained from rabbit, man, horse, and guinea pig, the only species thus far investigated. Circulating blood leucocytes as well as exudate cells contain this bactericidal substance. The lethal effects of phagocytin on bacteria may be influenced, depending on the particular microorganism, by either pH or ionic strength of the medium. The bactericidal action of phagocytin is only slightly reduced following digestion with trypsin, chymotrypsin or papain. The active ingredient is, however, non-dialyzable and apparently precipitated by trichloracetic acid. Data available at present are insufficient to define the chemical nature of phagocytin.

scholarly journals In Vitro Bactericidal Activity of Human β-Defensin 3 against Multidrug-Resistant Nosocomial Strains

2006 ◽  
Vol 50 (2) ◽  
pp. 806-809 ◽  
Author(s):  
Giuseppantonio Maisetta ◽  
Giovanna Batoni ◽  
Semih Esin ◽  
Walter Florio ◽  
Daria Bottai ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Pseudomonas Aeruginosa ◽  
Antimicrobial Activity ◽  
Bactericidal Activity ◽  
Stenotrophomonas Maltophilia ◽  
Bactericidal Effect ◽  
Multidrug Resistant ◽  
Bacterial Strains ◽  
Gram Negative

ABSTRACT The antimicrobial activity of human β-defensin 3 (hBD-3) against multidrug-resistant clinical isolates of Staphylococcus aureus, Enterococcus faecium, Pseudomonas aeruginosa, Stenotrophomonas maltophilia, and Acinetobacter baumannii was evaluated. A fast bactericidal effect (within 20 min) against all bacterial strains tested was observed. The presence of 20% human serum abolished the bactericidal activity of hBD-3 against gram-negative strains and reduced the activity of the peptide against gram-positive strains.

scholarly journals Activity of Human β-Defensin 3 Alone or Combined with Other Antimicrobial Agents against Oral Bacteria

2003 ◽  
Vol 47 (10) ◽  
pp. 3349-3351 ◽  
Author(s):  
Giuseppantonio Maisetta ◽  
Giovanna Batoni ◽  
Semih Esin ◽  
Filippo Luperini ◽  
Manuela Pardini ◽  
...  
Keyword(s):  
Streptococcus Mutans ◽  
Bactericidal Activity ◽  
Lactobacillus Acidophilus ◽  
Antimicrobial Agents ◽  
Bacterial Species ◽  
Bactericidal Effect ◽  
Oral Bacteria ◽  
Actinobacillus Actinomycetemcomitans ◽  
Streptococcus Sobrinus

ABSTRACT The in vitro activities of human β-defensin 3 (hBD-3) alone or combined with lysozyme, metronidazole, amoxicillin, and chlorhexidine were investigated with the oral bacteria Streptococcus mutans, Streptococcus sanguinis, Streptococcus sobrinus, Lactobacillus acidophilus, Actinobacillus actinomycetemcomitans, and Porphyromonas gingivalis. hBD-3 showed bactericidal activity against all of the bacterial species tested. The bactericidal effect was enhanced when the peptide was used in combination with the antimicrobial agents mentioned above.

scholarly journals Reg4 defenses the intestine against Salmonella infection via binding the flagellin

2021 ◽  
Author(s):  
Yongtao Xiao ◽  
weipeng wang ◽  
Ying lu ◽  
xinbei tian ◽  
shanshan chen ◽  
...  
Keyword(s):  
Salmonella Typhimurium ◽  
Bactericidal Activity ◽  
Intestinal Inflammation ◽  
Bactericidal Effect ◽  
Intestinal Epithelia ◽  
Food Borne ◽  
Negative Impacts ◽  
First Time

Salmonella Typhimurium is gram-negative flagellated bacteria that can cause food-borne gastroenteritis and diarrhea in humans and animals. The regenerating islet-derived family member 4 (Reg4) is overexpressed in the gastrointestinal tract during intestinal inflammation. However, the role of Reg4 in the intestinal inflammation induced by Salmonella Typhimurium is largely unknown. In this study, we reported for the first time that Reg4 has bactericidal activity against intestinal infection caused by Salmonella Typhimurium. In vivo, Reg4 could reduce the colonization of Salmonella Typhimurium and attenuate intestinal inflammation in the Salmonella Typhimurium-infected model. Additionally, the mice with the epithelial cell specific deletion of Reg4 (Reg4ΔIEC) exhibited more severe intestinal inflammation and more colonization of Salmonella Typhimurium. However, the administration of Reg4 could reverse these negative impacts. In vitro, Reg4 protein was showed to inhibit the growth of Salmonella Typhimurium. We further investigate the function motif of Reg4 and find that the "HDPQK" motif in Reg4 is essential to its bactericidal activity. Reg4 exerted the bactericidal effect by binding to the flagellin of Salmonella Typhimurium and suppressing its motility, adhesion, and invasion to the intestinal epithelia. In conclusion, our findings identify Reg4 as a novel antimicrobial peptide against infection by Salmonella Typhimurium and explore its possible mechanism, which may be of great significance for developing novel agents against flagellated micro pathogens.

scholarly journals Bactericidal action of ofloxacin, sulbactam-ampicillin, rifampin, and isoniazid on logarithmic- and stationary-phase cultures of Mycobacterium tuberculosis.

1996 ◽  
Vol 40 (10) ◽  
pp. 2296-2299 ◽  
Author(s):  
D Herbert ◽  
C N Paramasivan ◽  
P Venkatesan ◽  
G Kubendiran ◽  
R Prabhakar ◽  
...  
Keyword(s):  
Mycobacterium Tuberculosis ◽  
Stationary Phase ◽  
Bactericidal Activity ◽  
Exponential Phase ◽  
Drug Combinations ◽  
Bactericidal Action ◽  
Level Of Activity ◽  
Susceptible Isolate ◽  
Emergence Of Resistance

The bactericidal actions of ofloxacin and sulbactam-ampicillin, alone and in combination with rifampin and isoniazid, on exponential-phase and stationary-phase cultures of a drug-susceptible isolate of Mycobacterium tuberculosis were studied in vitro. In exponential-phase cultures, all drugs were bactericidal, with the higher concentrations of ofloxacin (5 micrograms/ml) and sulbactam-ampicillin (15 micrograms of ampicillin per ml) being as bactericidal as 1 microgram of isoniazid per ml or 1 microgram of rifampin per ml. In two-drug combinations, both drugs increased the levels of activity of isoniazid and rifampin and were almost as bactericidal as isoniazid-rifampin; they also appeared to increase the level of activity of isoniazid-rifampin in three-drug combinations. In contrast, ofloxacin and sulbactam-ampicillin had little bactericidal activity against stationary-phase cultures and were less active than isoniazid or rifampin alone. Furthermore, in two-drug or three-drug combinations, they did not increase the level of activity of isoniazid, rifampin, or isoniazid-rifampin. These findings suggest that ofloxacin and sulbactam-ampicillin are likely to be most useful in the early stages of treatment and in preventing the emergence of resistance to other drugs but are unlikely to be effective as sterilizing drugs helping to kill persisting lesional bacilli.

scholarly journals On the Bactericidal Effect exerted by Human Blood on certain species of Pathogenic Micro-Organisms and on the Antibactericidal Effects obtained by the addition to the blood in vitro of Dead Cultures of the Micro-Organisms in question

1902 ◽  
Vol 2 (4) ◽  
pp. 385-413 ◽  
Author(s):  
A. E. Wright ◽  
F. N. Windsor
Keyword(s):  
Streptococcus Pyogenes ◽  
Human Blood ◽  
Bactericidal Effect ◽  
Laboratory Animals ◽  
Bactericidal Action ◽  
Pathogenic Organisms ◽  
Micro Organisms

The fact that the blood of ordinary laboratory animals exerts a very marked bactericidal effect upon the Bacillus typhosus and the Spirillum cholerae asiaticae, while it exerts little or no effect upon the Staphylococcus and Streptococcus pyogenes, has hardly received the attention which it would seem to merit in view of the circumstance that these facts involve the important problem as to whether the blood exerts its bactericidal action upon pathogenic organisms generally, or only upon certain species of such micro-organisms.

scholarly journals The Novel β-Lactam Enhancer Zidebactam Augments theIn VivoPharmacodynamic Activity of Cefepime in a Neutropenic Mouse LungAcinetobacter baumanniiInfection Model

2019 ◽  
Vol 63 (4) ◽  
Author(s):  
S. S. Bhagwat ◽  
H. Periasamy ◽  
S. S. Takalkar ◽  
S. R. Palwe ◽  
H. N. Khande ◽  
...  
Keyword(s):  
Bactericidal Effect ◽  
Multidrug Resistant ◽  
Mouse Lung ◽  
Infection Model ◽  
Bactericidal Action ◽  
Content Type ◽  
Time Kill ◽  
The Impact

ABSTRACTWCK 5222 is a combination of cefepime and the high-affinity PBP2-binding β-lactam enhancer zidebactam. The cefepime-zidebactam combination is active against multidrug-resistant Gram-negative bacteria, including carbapenemase-expressingAcinetobacter baumannii. The mechanism of action of the combination involves concurrent multiple penicillin binding protein inhibition, leading to the enhanced bactericidal action of cefepime. The aim of the present study was to assess the impact of the zidebactam-mediated enhancedin vitrobactericidal action in modulating the percentage of the time that the free drug concentration remains above the MIC (percentfT>MIC) for cefepime required for thein vivokilling ofA. baumannii. Cefepime and cefepime-zidebactam MICs were comparable and ranged from 2 to 16 mg/liter for theA. baumanniistrains (n = 5) employed in the study. Time-kill studies revealed the improved killing of these strains by the cefepime-zidebactam combination compared to that by the constituents alone. Employing a neutropenic mouse lung infection model, exposure-response analyses for all theA. baumanniistrains showed that the cefepimefT>MIC required for 1-log10kill was 38.9%. In the presence of a noneffective dose of zidebactam, the cefepimefT>MIC requirement dropped significantly to 15.5%, but it still rendered a 1-log10kill effect. Thus, zidebactam mediated the improvement in cefepime’s bactericidal effect observed in time-kill studies, manifestedin vivothrough the lowering of cefepime’s pharmacodynamic requirement. This is a first-ever study demonstrating a β-lactam enhancer role of zidebactam that helps augment thein vivoactivity of cefepime by reducing the magnitude of its pharmacodynamically relevant exposures againstA. baumannii.

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