Postantibiotic effect of aminoglycosides on Gram-negative bacteria evaluated by a new method

1988 ◽  
Vol 22 (1) ◽  
pp. 23-33 ◽  
Author(s):  
Barbro Isaksson ◽  
Lennart Nilsson ◽  
Rolf Maller ◽  
Lars Sör´n
Keyword(s):  
New Method ◽  
Gram Negative Bacteria ◽  
Postantibiotic Effect ◽  
Gram Negative

A new method for the detection of microbial proteolytic enzymes in milk

1982 ◽  
Vol 49 (2) ◽  
pp. 209-219 ◽  
Author(s):  
Allan J. Cliffe ◽  
Barry A. Law
Keyword(s):  
Proteolytic Enzymes ◽  
New Method ◽  
Gram Negative Bacteria ◽  
Optimum Conditions ◽  
Sample Processing ◽  
Gram Negative ◽  
Alternative Method ◽  
Simple Alternative ◽  
Extracellular Proteinases

SUMMARYOptimum conditions have been determined for the use of Hide Powder Azure (HPA) to estimate extracellular proteinases produced by psychrotrophic Gram-negative bacteria. This assay is quicker, more precise and 3·2 times more sensitive than assays of soluble N released from casein. It provides a simple alternative method for monitoring proteinase purification schemes. With the modification described it is now possible to determine proteinase activities directly in milk. In its simplest form the HPA assay is sufficiently sensitive to detect proteinases produced by as few as 1·5 x 106 c.f.u. ml-1 psychrobtrophs without the necessity for any sample processing.

scholarly journals In Vitro Pharmacodynamic Studies of L-749,345 in Comparison with Imipenem and Ceftriaxone against Gram-Positive and Gram-Negative Bacteria

1998 ◽  
Vol 42 (9) ◽  
pp. 2365-2370 ◽  
Author(s):  
Inga Odenholt ◽  
Elisabeth Löwdin ◽  
Otto Cars
Keyword(s):  
Staphylococcus Aureus ◽  
Pseudomonas Aeruginosa ◽  
Comparative Studies ◽  
Gram Negative Bacteria ◽  
Postantibiotic Effect ◽  
Gram Positive ◽  
Gram Negative ◽  
Methicillin Resistant ◽  
Gram Negative Organisms

ABSTRACT L-749,345 is a new parenteral carbapenem with a very long half-life similar to that of ceftriaxone. The aim of the present study was to investigate different pharmacodynamic parameters of L-749,345 in comparison with those of ceftriaxone and imipenem. The following studies were performed: (i) comparative studies of the MICs of L-749,345, imipenem, and ceftriaxone for 70 strains of gram-positive and gram-negative bacteria; (ii) comparative studies of the rate of killing of gram-positive and gram-negative bacteria by L-749,345, imipenem, and ceftriaxone; (iii) studies of the postantibiotic effects of L-749,345, imipenem, and ceftriaxone; and (iv) studies of the postantibiotic sub-MIC effects of L-749,345, imipenem, and ceftriaxone. Significantly lower MICs of L-749,345 compared with those of ceftriaxone were found for all gram-negative organisms except Haemophilus influenzae. The MICs of L-749,345 were similar to those of imipenem for all organisms except Pseudomonas aeruginosa and methicillin-resistant Staphylococcus aureus, for which the MICs of L-749,345 were higher. A concentration-dependent killing of methicillin-resistant S. aureus but not methicillin-susceptible strains was noted for both L-749,345 and imipenem. All three of the investigated drugs exhibited a postantibiotic effect against the gram-positive strains but exhibited no postantibiotic effect against the gram-negative strains.

scholarly journals The postantibiotic effect of imipenem: relationship with drug concentration, duration of exposure, and MIC.

1997 ◽  
Vol 41 (8) ◽  
pp. 1735-1737 ◽  
Author(s):  
W J Munckhof ◽  
D Olden ◽  
J D Turnidge
Keyword(s):  
Escherichia Coli ◽  
Drug Concentration ◽  
Drug Exposure ◽  
Gram Negative Bacteria ◽  
Postantibiotic Effect ◽  
Gram Positive ◽  
Time Curve ◽  
Gram Negative ◽  
Concentration Time ◽  
Drug Concentrations

The postantibiotic effect (PAE) of imipenem against Escherichia coli was measured at a wide variety of drug concentrations and times of exposure. We observed that the area under the concentration-time curve of drug exposure (AUC), the product of time of exposure and concentration of drug, is a much better predictor of the duration of the PAE than either parameter alone. We also measured the PAE of imipenem against strains of gram-positive and gram-negative bacteria for which MICs varied widely. The E50, the AUC required to produce 50% of the maximum PAE, is correlated with the MIC and is independent of species. This may explain why the duration of the PAE differs for bacteria of the same species for which MICs are different.

scholarly journals Washing with contaminated bar soap is unlikely to transfer bacteria

1988 ◽  
Vol 101 (1) ◽  
pp. 135-142 ◽  
Author(s):  
John E. Heinze ◽  
Frank Yackovich
Keyword(s):  
Escherichia Coli ◽  
Pseudomonas Aeruginosa ◽  
New Method ◽  
Complete Agreement ◽  
Gram Negative Bacteria ◽  
Gram Negative ◽  
Total Survival ◽  
Test Bacterium ◽  
Frequent Use ◽  
Additional Procedure

SUMMARYRecent reports of the isolation of microorganisms from used soap bars have raised the concern that bacteria may be transferred from contaminated soap bars during handwashing. Since only one study addressing this question has been published, we developed an additional procedure to test this concern. In our new method prewashed and softened commercial deodorant soap bars (0·8% triclocarban) not active against Gram-negative bacteria were inoculated withEscherichia coliandPseudomonas aeruginosato give mean total survival levels of 4·4 × 105c.f.u. per bar which was 70-fold higher than those reported on used soap bars. Sixteen panelists were instructed to wash with the inoculated bars using their normal handwashing procedure. After washing, none of the 16 panelists had detectable levels of either test bacterium on their hands. Thus, the results obtained using our new method were in complete agreement with those obtained with the previously published method even though the two methods differ in a number of procedural aspects. These findings, along with other published reports, show that little hazard exists in routine handwashing with previously used soap bars and support the frequent use of soap and water for handwashing to prevent the spread of disease.

Bacterial-Mucosal Cell Junctional Complexes

1974 ◽  
Vol 32 ◽  
pp. 144-145
Author(s):  
Roger C. Wagner
Keyword(s):  
Intestinal Wall ◽  
Rat Colon ◽  
Mucosal Cell ◽  
Gram Negative Bacteria ◽  
Gram Negative ◽  
Mucosal Cells ◽  
Mucosal Lining ◽  
Degenerative Alterations ◽  
Junctional Complexes ◽  
Intestinal Mucosal Cells

Bacteria exhibit the ability to adhere to the apical surfaces of intestinal mucosal cells. These attachments either precede invasion of the intestinal wall by the bacteria with accompanying inflammation and degeneration of the mucosa or represent permanent anchoring sites where the bacteria never totally penetrate the mucosal cells.Endemic gram negative bacteria were found attached to the surface of mucosal cells lining the walls of crypts in the rat colon. The bacteria did not intrude deeper than 0.5 urn into the mucosal cells and no degenerative alterations were detectable in the mucosal lining.

Rapid demonstration of septic or infectious arthritis due to Gram-negative bacteria

1992 ◽  
Vol 50 (1) ◽  
pp. 686-687
Author(s):  
Jacob S. Hanker ◽  
Paul R. Gross ◽  
Beverly L. Giammara
Keyword(s):  
Chronic Arthritis ◽  
Blood Cultures ◽  
Gram Negative Bacteria ◽  
Infectious Arthritis ◽  
Bacterial Arthritis ◽  
Gram Positive ◽  
Gram Negative ◽  
Gram Positive Bacteria

Blood cultures are positive in approximately only 50 per cent of the patients with nongonococcal bacterial infectious arthritis and about 20 per cent of those with gonococcal arthritis. But the concept that gram-negative bacteria could be involved even in chronic arthritis is well-supported. Gram stains are more definitive in staphylococcal arthritis caused by gram-positive bacteria than in bacterial arthritis due to gram-negative bacteria. In the latter situation where gram-negative bacilli are the problem, Gram stains are helpful for 50% of the patients; they are only helpful for 25% of the patients, however, where gram-negative gonococci are the problem. In arthritis due to gram-positive Staphylococci. Gramstained smears are positive for 75% of the patients.

Ultrastructure of periplasmic bodies in gram-negative bacteria

1990 ◽  
Vol 48 (3) ◽  
pp. 640-641
Author(s):  
Xie Nianming ◽  
Ding Shaoqing ◽  
Wang Luping ◽  
Yuan Zenglin ◽  
Zhan Guolai ◽  
...  
Keyword(s):  
Electron Microscope ◽  
Campylobacter Jejuni ◽  
Proteus Mirabilis ◽  
Shigella Flexneri ◽  
Morphological Description ◽  
Gram Negative Bacteria ◽  
Periplasmic Space ◽  
Clostridium Tetani ◽  
Gram Negative ◽  
Brucella Canis

Perhaps the data about periplasmic enzymes are obtained through biochemical methods but lack of morphological description. We have proved the existence of periplasmic bodies by electron microscope and described their ultrastructures. We hope this report may draw the attention of biochemists and mrophologists to collaborate on researches in periplasmic enzymes or periplasmic bodies with each other.One or more independent bodies may be seen in the periplasmic space between outer and inner membranes of Gram-negative bacteria, which we called periplasmic bodies. The periplasmic bodies have been found in seven species of bacteria at least, including the Pseudomonas aeroginosa. Shigella flexneri, Echerichia coli. Yersinia pestis, Campylobacter jejuni, Proteus mirabilis, Clostridium tetani. Vibrio cholerae and Brucella canis.

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