Glycylcyclines are a class of antibiotics derived from tetracycline. These tetracycline analogues are specifically designed to overcome two common mechanisms of tetracycline resistance, namely resistance mediated by acquired efflux pumps and/or ribosomal protection. Presently, tigecycline is the only glycylcycline approved for antibiotic use.
The development of these agents was spurred by the increasing prevalence of bacteria resistant to tetracyclines. These agents were first synthesized in the early 1990s by making modifications to the tetracyclines. By adding a bulky N,N-dimethylglycylamido side chain to position 9 of minocycline, the compound became less susceptible to tetracycline resistance mediated by acquired efflux pumps and/or ribosomal protection. Further development of this initial work led to the creation of tigecycline, the first glycylcycline available for clinical use.[ citation needed ]
Glycylcycline antibiotics have a similar mechanism of action as tetracycline antibiotics. They block protein synthesis hence preventing bacterial reproduction. Both classes of antibiotics bind to the 30S ribosomal subunit to prevent the amino-acyl tRNA from binding to the A site of the ribosome. However, the glycylcyclines appear to bind more effectively than the tetracyclines. [2]
While glycylcyclines have greater efficacy against organisms with tetracycline resistance mediated by acquired efflux pumps and/or ribosomal protection, glycylcyclines are not effective against organisms with chromosomal efflux pumps, such as Pseudomonas and Proteae. [3]
Since glycylcyclines are similar to tetracyclines, they share many of the same side effects and contraindications as tetracyclines. These side effects may include nausea/vomiting, headache, photosensitivity, discoloration of growing teeth, and fetal damage. [4]
These antibiotics should not be given to pregnant women due to risk of fetal harm. Additionally, these drugs should not be administered during periods of tooth development because of the risk of tooth discoloration. Due to glycylcyclines' similarities with tetracyclines, hypersensitivity reactions to tetracycline antibiotics may predispose one to hypersensitivity reactions with glycylcycline antibiotics; hence, glycylcyclines should be used with caution in these patients.[ citation needed ]
Ampicillin is an antibiotic belonging to the aminopenicillin class of the penicillin family. The drug is used to prevent and treat a number of bacterial infections, such as respiratory tract infections, urinary tract infections, meningitis, salmonellosis, and endocarditis. It may also be used to prevent group B streptococcal infection in newborns. It is used by mouth, by injection into a muscle, or intravenously.
Tetracycline, sold under various brand names, is an oral antibiotic in the tetracyclines family of medications, used to treat a number of infections, including acne, cholera, brucellosis, plague, malaria, and syphilis.
Ertapenem, sold under the brand name Invanz, is a carbapenem antibiotic medication used for the treatment of infections of the abdomen, the lungs, the upper part of the female reproductive system, and the diabetic foot.
Clindamycin is a lincosamide antibiotic medication used for the treatment of a number of bacterial infections, including osteomyelitis (bone) or joint infections, pelvic inflammatory disease, strep throat, pneumonia, acute otitis media, and endocarditis. It can also be used to treat acne, and some cases of methicillin-resistant Staphylococcus aureus (MRSA). In combination with quinine, it can be used to treat malaria. It is available by mouth, by injection into a vein, and as a cream or a gel to be applied to the skin or in the vagina.
Tigecycline, sold under the brand name Tygacil, is a tetracycline antibiotic medication for a number of bacterial infections. It is a glycylcycline administered intravenously. It was developed in response to the growing rate of antibiotic resistant bacteria such as Staphylococcus aureus, Acinetobacter baumannii, and E. coli. As a tetracycline derivative antibiotic, its structural modifications has expanded its therapeutic activity to include Gram-positive and Gram-negative organisms, including those of multi-drug resistance.
Carbapenems are a class of very effective antibiotic agents most commonly used for treatment of severe bacterial infections. This class of antibiotics is usually reserved for known or suspected multidrug-resistant (MDR) bacterial infections. Similar to penicillins and cephalosporins, carbapenems are members of the beta-lactam antibiotics drug class, which kill bacteria by binding to penicillin-binding proteins, thus inhibiting bacterial cell wall synthesis. However, these agents individually exhibit a broader spectrum of activity compared to most cephalosporins and penicillins. Furthermore, carbapenems are typically unaffected by emerging antibiotic resistance, even to other beta-lactams.
Amikacin is an antibiotic medication used for a number of bacterial infections. This includes joint infections, intra-abdominal infections, meningitis, pneumonia, sepsis, and urinary tract infections. It is also used for the treatment of multidrug-resistant tuberculosis. It is used by injection into a vein using an IV or into a muscle.
Tetracyclines are a group of broad-spectrum antibiotic compounds that have a common basic structure and are either isolated directly from several species of Streptomyces bacteria or produced semi-synthetically from those isolated compounds. Tetracycline molecules comprise a linear fused tetracyclic nucleus to which a variety of functional groups are attached. Tetracyclines are named after their four ("tetra-") hydrocarbon rings ("-cycl-") derivation ("-ine"). They are defined as a subclass of polyketides, having an octahydrotetracene-2-carboxamide skeleton and are known as derivatives of polycyclic naphthacene carboxamide. While all tetracyclines have a common structure, they differ from each other by the presence of chloro, methyl, and hydroxyl groups. These modifications do not change their broad antibacterial activity, but do affect pharmacological properties such as half-life and binding to proteins in serum.
Temafloxacin is a fluoroquinolone antibiotic drug which was withdrawn from sale in the United States shortly after its approval in 1992 because of serious adverse effects resulting in three deaths. It is not marketed in Europe.
Cefoxitin is a second-generation cephamycin antibiotic developed by Merck & Co., Inc. from Cephamycin C in the year following its discovery, 1972. It was synthesized in order to create an antibiotic with a broader spectrum. It is often grouped with the second-generation cephalosporins. Cefoxitin requires a prescription and as of 2010 is sold under the brand name Mefoxin by Bioniche Pharma, LLC. The generic version of cefoxitin is known as cefoxitin sodium.
Prulifloxacin is an older synthetic antibiotic of the fluoroquinolone class undergoing clinical trials prior to a possible NDA submission to the U.S. Food and Drug Administration (FDA). It is a prodrug which is metabolized in the body to the active compound ulifloxacin. It was developed over two decades ago by Nippon Shinyaku Co. and was patented in Japan in 1987 and in the United States in 1989.
A protein synthesis inhibitor is a compound that stops or slows the growth or proliferation of cells by disrupting the processes that lead directly to the generation of new proteins.
Carindacillin (INN), also known as carbenicillin indanyl (USAN), is a penicillin antibiotic. It is a prodrug of carbenicillin.
Ceftaroline fosamil (INN), brand name Teflaro in the US and Zinforo in Europe, is a cephalosporin antibiotic with anti-MRSA activity. Ceftaroline fosamil is a prodrug of ceftaroline. It is active against methicillin-resistant Staphylococcus aureus (MRSA) and other Gram-positive bacteria. It retains some activity of later-generation cephalosporins having broad-spectrum activity against Gram-negative bacteria, but its effectiveness is relatively much weaker. It is currently being investigated for community-acquired pneumonia and complicated skin and skin structure infection.
Radezolid is a novel oxazolidinone antibiotic being developed by Melinta Therapeutics, Inc. for the treatment of bacterial acne.
SmeT is a transcriptional repressor protein of 24.6 kDa, found in the pathogenic bacteria Stenotrophomonas maltophilia. SmeT is responsible for the regulation of the Multidrug Resistance (MDR) efflux pump, SmeDEF, that gives the bacteria resistance to several antibiotics including macrolides, TMP/SMX, tetracycline, chloramphenicol, quinolones and erythromycin. SmeT is encoded 223 bp upstream of SmeDEF, with just 56 base pairs between their transcription start sites and an overlapping region between the promoters. The production of the SmeT protein downregulates its own transcription, along with that of the efflux pump by sterically hindering the binding of RNA Polymerase to the DNA. SmeDEF was the first MDR pump discovered in the S. maltophilia species. The pump is named by its different parts: SmeE, the transporter itself that spans the plasma membrane, SmeF, the protein on the outer portion of the membrane, and SmeD, a membrane fusion protein. On general purpose media and no selectors, the genes for MDR pumps are typically not expressed, and the repressor is found bound to the DNA. In fact, mutations in SmeT that lead to overexpression of SmeDEF can pose fitness challenges to the bacteria. However, this overexpression has been identified in the bacterium and may pose a threat to our health.
Quinolone antibiotics constitute a large group of broad-spectrum bacteriocidals that share a bicyclic core structure related to the substance 4-quinolone. They are used in human and veterinary medicine to treat bacterial infections, as well as in animal husbandry, specifically poultry production.
Neisseria gonorrhoeae, the bacterium that causes the sexually transmitted infection gonorrhea, has developed antibiotic resistance to many antibiotics. The bacteria was first identified in 1879.
Omadacycline, sold under the brand name Nuzyra, is a broad spectrum antibiotic medication belonging to the aminomethylcycline subclass of tetracycline antibiotics. In the United States, it was approved in October 2018, for the treatment of community-acquired bacterial pneumonia and acute skin and skin structure infections.
Ceftazidime/avibactam, sold under the brand name Avycaz among others, is a fixed-dose combination medication composed of ceftazidime, a cephalosporin antibiotic, and avibactam, a β-lactamase inhibitor. It is used to treat complicated intra-abdominal infections, urinary tract infections, and pneumonia. It is only recommended when other options are not appropriate. It is given by injection into a vein.