Antibiotics

Nigericin is an ionophore antibiotic isolated from Streptomyces hygroscopicus. It has been shown to suppress DNA synthesis in Ehrlich ascites carcinoma. Nigericin is insoluble in water, but soluble in methanol and chloroform.

Nigericin sodium disrupts membrane potential by acting as an antiporter of H+ and K+ ions by exchanging K+ for H+. This causes a rapid decrease in intracellular pH.

Nisin is a polypeptide antibiotic known as a lantibiotic. It has been isolated from Lactococcus lactis. Produced by gram-positive bacteria, the role of nisin is to reduce competitive strain due to the presence of other gram-positive bacteria.

Nitrofurantoin is a bacteriostatic, nitrofuran antibiotic targeting gram-negative and gram-positive bacteria such as Enterococci, Staphylococci, Streptococci, Corynebacterium, and E. Coli. It has been used to study nitrofurantoin bacterial susceptibility and nitrofurantoin-induced toxicity. Additionally, it is a substrate for bacterial nitrofuran reductase.

Norfloxacin is a first generation fluoroquinolone antibiotic targeting primarily gram-negative bacteria responsible for causing urinary tract infections. It is a derivative of pefloxacin.

Nourseothricin is a broad-spectrum antibiotic derived from Streptomyces noursei. In addition to being effective on prokaryotic cells of gram-positive and gram-negative bacteria, various fungi including Candida albicans, and certain DNA and RNA viruses, it is also effective on eukaryotic cells of higher eukaryotes. It has been used as a selection agent for cells containing the gene conferring resistance to it.

GoldBio nourseothricin is a mixture of four streptothricin compounds: D and F (>85%) as well as C and E (<15%).

Ofloxacin is a second generation fluoroquinolone antibiotic targeting gram-negative and gram-positive bacteria. It is an analog of nalidixic acid.

Oxolinic acid is a synthetic quinolone antibiotic targeting gram-negative bacteria, especially those responsible for causing urinary tract infections. It has also been reported to be effective against Burkholderia glumae, a bacteria causing grain rot, sheath rot, seedling rot, and bacterial panicle blight. It has been useful in studying transmissible resistance mechanisms of E. coli and S. enterica. It can be used to isolate Gardnerella vaginalis and as a dopamine reuptake inhibitor in neurological research.

Oxytetracycline is a tetracycline antibiotic derived from Streptomyces rimosus. It targets gram-positive and gram-negative bacteria and several Mycoplasma species. Oxytetracycline has been used to study its resistance gene, otrA and in fluorescence analysis of liver cells.

Additionally, oxytetracycline is used as a selective agent in OGYE, a selective medium for yeasts and molds. It has been used to prevent fire blight in apples and pears and has been shown to be a better alternative to streptomycin against fire blight disease.

Oxytetracycline is a tetracycline antibiotic derived from Streptomyces rimosus. It targets gram-positive and gram-negative bacteria and several Mycoplasma species. Oxytetracycline has been used to study its resistance gene, otrA and in fluorescence analysis of liver cells.

Additionally, oxytetracycline is used as a selective agent in OGYE, a selective medium for yeasts and molds. It has been used to prevent fire blight in apples and pears and has been shown to be a better alternative to streptomycin against fire blight disease.

Oxytetracycline is a tetracycline antibiotic derived from Streptomyces rimosus. It targets gram-positive and gram-negative bacteria and several Mycoplasma species. Oxytetracycline has been used to study its resistance gene, otrA and in fluorescence analysis of liver cells.

Additionally, oxytetracycline is used as a selective agent in OGYE, a selective medium for yeasts and molds. It has been used to prevent fire blight in apples and pears and has been shown to be a better alternative to streptomycin against fire blight disease.

Paromomycin is an aminoglycoside antibiotic isolated from Streptomyces rimosus. It targets a variety of gram-negative and gram-positive bacteria as well as several protozoan species. It displays activity similar to that of neomycin. Paromomycin sulfate is freely soluble.

Perfloxacin is a fluoroquinolone antibiotic and is an analog of norfloxacin. It targets gram-negative and gram-positive bacteria as well as several Mycoplasma species. It is commonly used against Gonococcal species and to induce achilles tendon toxicity in rodents.

Penicillin G is a β-lactam antibiotic produced by the Penicillium fungus. It has shown efficacy against a variety of Streptococcus species as well as non-penicillinase producing Staphylococcus species. The potassium salt is useful in studying Staphylococcus murosomes and Streptococcus mutans. This product has been tested against both sensitive and resistant cells.

Penicillin G is a β-lactam antibiotic produced by the Penicillium fungus. It has shown efficacy against a variety of Streptococcus species as well as non-penicillinase producing Staphylococcus species.

Pipemidic acid is a pyridopyrimidine antibiotic with similar properties to quinolone antibiotics. It is used to study damage and mutations in DNA as well as lymphocyte blastogenesis and interferon-gamma production. It can be used as a cell selection agent.

Piperacillin is an extended-spectrum β-lactam antibiotic resistant to many β-lactamases. It is derived from ampicillin and targets gram-negative and gram-positive bacteria. Additionally, piperacillin has been used in studies on optimization of antimicrobial therapy in patients with sepsis and to study piperacillin allergic reactions. It has also been used to study multidrug resistant organisms.

Piperacillin is an extended-spectrum β-lactam antibiotic resistant to many β-lactamases. It is derived from ampicillin and targets gram-negative and gram-positive bacteria. Additionally, piperacillin has been used in studies on optimization of antimicrobial therapy in patients with sepsis and to study piperacillin allergic reactions. It has also been used to study multidrug resistant organisms.

Polymyxin B sulfate is a polypeptide antibiotic mixture of B1, B2, and B3 polymyxins. Each of these fractions vary by a fatty acid group and exhibit marginal MIC differences when compared. Polymyxin B is most effective against gram-negative bacteria. It has been shown to work against Pseudomonas aeruginosa, Pseudomonas viridiflava, and Erwinia carotovora. Polymyxin B is freely soluble in aqueous solution.

Puromycin is an aminonucleoside antibiotic that causes early chain termination within the ribosome during translation. This inhibition of translation is effective in both in vivo and in vitro applications, making it an ideal tool for protein synthesis studies. While selection for E. coli cells is possible with puromycin, it is more commonly and effectively used for mammalian cell selection.

The growth of bacteria, protozoa, algae and mammalian cells is quickly halted by puromycin. However, cells with the pac gene have resistance. Its gene product is puromycin-N-acetyl-transferase which inactivates puromycin through acetylation.

Research has shown puromycin to be effective against certain tumors.

Pyrazinamide is an anti-tubercular antibiotic. It is also used to study ways to prevent liver toxicity and in the formation of polymeric copper complexes.

Although the mechanism of action of pyrazinamide is not well understood, it is thought that upon entering a target cell, it is converted to pyrazinoic acid or POA. This conversion results in altered cellular permeability and decreased internal pH due to POA accumulation in the cytoplasm. This may inhibit fatty acid synthesis.