The possible significance of impurities in the chemotherapeutic action of penicillin was first suggested by Cornman (1944) and by Lewis (1944), who observed that impure but not pure penicillin possessed a selective lethal action against rat and mouse sarcoma cells. Dunham and Rake in 1945 demonstrated that impure penicillin exerted a definite effect on the motility of Treponema pallidum, wherea...

Background and purpose: Highly consumption of antibiotics and their entrance into the environment has increased concerns all over the world. These compounds enter to the environment through an incomplete metabolism and a considerable amount of them cannot be removed using usual waste filtration systems. Therefore, the present study aimed to investigate the feasibility of using ultraviolet radia...

The antibacterial activities of a number of amide derivatives of penicillin against both penicillin-sensitive and penicillin-resistant cultures were determined. Several of them were found to possess significant inhibitory activity against certain gram-positive bacteria. The amides, although resistant to the destructive action of beta-lactamase, did not protect G in competitive experiments. One ...

6-Aminopenicillanic acid may be quantitatively estimated by its reaction with fluorescamine in the concentration range of 1 to 10 micrograms/ml. The difference in reactivity between 6-aminopenicillanic acid and benzylpenicillin, which does not react with fluorescamine, can be used to determine penicillin acylase activity and obtain data on enzyme parameters and inhibitors. Unlike amino acids an...

In this study, we developed and validated a method for the extraction, identification, and quantitation of penicillin G and its metabolites (penilloic acid and penillic acid) in a variety of citrus fruits by employing sequential liquid/liquid and solid-phase extraction techniques in conjunction with UHPLC-MS/MS. Two product ion transitions per analyte were required for identification, which con...

The crystallization of three catalytically inactive mutants of penicillin V acylase (PVA) from Bacillus sphaericus in precursor and processed forms is reported. The mutant proteins crystallize in different primitive monoclinic space groups that are distinct from the crystal forms for the native enzyme. Directed mutants and clone constructs were designed to study the post-translational autoprote...

Prophylactic penicillin has been recommended for use in asplenic patients and postsplenectomy patients. A laboratory model using aerosolized pneumococci has been devised to test the effectiveness of prophylactic penicillin in a manner analogous to human experience. There is increased mortality. over time, in asplenic mice exposed to aerosolized type Ill Streptococcus pneumoniae. One hundred twe...

In Streptococcus pyogenes, we have described the two-component signal transduction sensor and regulatory systems, CovR/S affect the antimicrobial susceptibility including penicillin G before. But the mechanism how two-component sensor protein CovS modulates penicillin G susceptibility has not been elucidated till date. This study aimed to determine how the CovS affected penicillin G susceptibil...

Background.  Antimicrobial treatment and chemoprophylaxis of patients and their close contacts is critical to reduce the morbidity and mortality and prevent secondary cases of meningococcal disease. Through the 1990's, the prevalence of antimicrobial resistance to commonly used antimicrobials among Neisseria meningitidis was low in the United States. Susceptibility testing was performed to asce...

A simple, accurate, and rapid method for the quantitative analysis of two penicillin drugs is developed. The method is based on the formation of a blue penicillin-azure A ion pair that can be extracted into chloroform in phosphate-citric acid buffer of pH 2.6-6.8 at room temperature (25 + 2oC). The molar absorptivities for sodium penicillin G and potassium penicillin V at 660 nm are 6.74 x l03 ...