The macrolides are a class of natural products that consist of a large macrocyclic lactone ring to which one or more deoxy sugars, usually cladinose and desosamine, may be attached. The lactone rings are usually 14-, 15-, or 16-membered. Macrolides belong to the polyketide class of natural products. Some macrolides have antibiotic or antifungal activity and are used as pharmaceutical drugs. Rapamycin is also a macrolide and was originally developed as an antifungal, but is now used as an immunosuppressant drug and is being investigated as a potential longevity therapeutic.
Streptococcus is a genus of gram-positive coccus or spherical bacteria that belongs to the family Streptococcaceae, within the order Lactobacillales, in the phylum Bacillota. Cell division in streptococci occurs along a single axis, so as they grow, they tend to form pairs or chains that may appear bent or twisted. This differs from staphylococci, which divide along multiple axes, thereby generating irregular, grape-like clusters of cells. Most streptococci are oxidase-negative and catalase-negative, and many are facultative anaerobes.
Methicillin, also known as meticillin, is a narrow-spectrum β-lactam antibiotic of the penicillin class.
Streptococcus pneumoniae, or pneumococcus, is a Gram-positive, spherical bacteria, alpha-hemolytic or beta-hemolytic, aerotolerant anaerobic member of the genus Streptococcus. They are usually found in pairs (diplococci) and do not form spores and are non motile. As a significant human pathogenic bacterium S. pneumoniae was recognized as a major cause of pneumonia in the late 19th century, and is the subject of many humoral immunity studies.
Clindamycin is an 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.
The viridans streptococci are a large group of commensal streptococcal Gram-positive bacteria species that are α-hemolytic, producing a green coloration on blood agar plates, although some species in this group are actually γ-hemolytic, meaning they produce no change on blood agar. The pseudo-taxonomic term "Streptococcus viridans" is often used to refer to this group of species, but writers who do not like to use the pseudotaxonomic term prefer the terms viridans streptococci, viridans group streptococci (VGS), or viridans streptococcal species.
Bacitracin is a polypeptide antibiotic. It is a mixture of related cyclic peptides produced by Bacillus licheniformis bacteria, that was first isolated from the variety "Tracy I" in 1945. These peptides disrupt Gram-positive bacteria by interfering with cell wall and peptidoglycan synthesis.
Haemophilus influenzae is a Gram-negative, coccobacillary, facultatively anaerobic capnophilic pathogenic bacterium of the family Pasteurellaceae. H. influenzae was first described in 1892 by Richard Pfeiffer during an influenza pandemic. He incorrectly described Haemophilus influenzae as the causative microbe, which retains "influenza" in its name.
Carbapenems are a class of very effective antibiotic agents most commonly used for the 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 class of antibiotics, 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.
Hemolysis is the breakdown of red blood cells. The ability of bacterial colonies to induce hemolysis when grown on blood agar is used to classify certain microorganisms. This is particularly useful in classifying streptococcal species. A substance that causes hemolysis is a hemolysin.
Antibiotic sensitivity testing or antibiotic susceptibility testing is the measurement of the susceptibility of bacteria to antibiotics. It is used because bacteria may have resistance to some antibiotics. Sensitivity testing results can allow a clinician to change the choice of antibiotics from empiric therapy, which is when an antibiotic is selected based on clinical suspicion about the site of an infection and common causative bacteria, to directed therapy, in which the choice of antibiotic is based on knowledge of the organism and its sensitivities.
Gemifloxacin mesylate is an oral broad-spectrum quinolone antibacterial agent used in the treatment of acute bacterial exacerbation of chronic bronchitis and mild-to-moderate pneumonia. Vansen Pharma Inc. has licensed the active ingredient from LG Life Sciences of Korea.
Etest is a way of determining antimicrobial sensitivity by placing a strip impregnated with antimicrobials onto an agar plate. A strain of bacterium or fungus will not grow near a concentration of antibiotic or antifungal if it is sensitive. For some microbial and antimicrobial combinations, the results can be used to determine a minimum inhibitory concentration (MIC). Etest is a proprietary system manufactured by bioMérieux. It is a laboratory test used in healthcare settings to help guide physicians by indicating what concentration of antimicrobial could successfully be used to treat patients' infections.
Cefodizime is a 3rd generation cephalosporin antibiotic with broad spectrum activity against aerobic gram positive and gram negative bacteria. Clinically, it has been shown to be effective against upper and lower respiratory tract infections, urinary tract infections, and gonorrhea. Cefodizime is a bactericidal antibiotic that targets penicillin-binding proteins (PBPs) 1A/B, 2, and 3 resulting in the eventual death of the bacterial cell. In vivo experimental models of infection showed that bacterial clearance by this drug is at least as effective compared with other 3rd generation cephalosporins. It has similar adverse effect profile to other 3rd generation cephalosporins as well, mainly being limited to gastrointestinal or dermatological side effects.
Ceftobiprole (Zevtera/Mabelio) is a fifth-generation cephalosporin for the treatment of hospital-acquired pneumonia and community-acquired pneumonia. It is marketed by Basilea Pharmaceutica in the United Kingdom, Germany, Switzerland and Austria under the trade name Zevtera, in France and Italy under the trade name Mabelio. Like other cephalosporins, ceftobiprole exerts its antibacterial activity by binding to important penicillin-binding proteins and inhibiting their transpeptidase activity which is essential for the synthesis of bacterial cell walls. Ceftobiprole has high affinity for penicillin-binding protein 2a of methicillin-resistant Staphylococcus aureus strains and retains its activity against strains that express divergent mecA gene homologues. Ceftobiprole also binds to penicillin-binding protein 2b in Streptococcus pneumoniae (penicillin-intermediate), to penicillin-binding protein 2x in Streptococcus pneumoniae (penicillin-resistant), and to penicillin-binding protein 5 in Enterococcus faecalis.
A pneumococcal infection is an infection caused by the bacterium Streptococcus pneumoniae, which is also called the pneumococcus. S. pneumoniae is a common member of the bacterial flora colonizing the nose and throat of 5–10% of healthy adults and 20–40% of healthy children. However, it is also a cause of significant disease, being a leading cause of pneumonia, bacterial meningitis, and sepsis. The World Health Organization estimates that in 2005 pneumococcal infections were responsible for the death of 1.6 million children worldwide.
Streptococcus anginosus is a species of Streptococcus. This species, Streptococcus intermedius, and Streptococcus constellatus constitute the anginosus group, which is sometimes also referred to as the milleri group after the previously assumed but later refuted idea of a single species Streptococcus milleri. Phylogenetic relatedness of S. anginosus, S. constellatus, and S. intermedius has been confirmed by rRNA sequence analysis.
Streptococcus pseudopneumoniae is a gram-positive coccus that may cause pneumonia in humans. It was first described in 2004. The organism is often mistaken for S. pneumoniae and its clinical importance is as yet uncertain. It seems likely that most cases of S. pseudopneumoniae pneumonia are misdiagnosed as S. pneumoniae.
Cephalosporins are a broad class of bactericidal antibiotics that include the β-lactam ring and share a structural similarity and mechanism of action with other β-lactam antibiotics. The cephalosporins have the ability to kill bacteria by inhibiting essential steps in the bacterial cell wall synthesis which in the end results in osmotic lysis and death of the bacterial cell. Cephalosporins are widely used antibiotics because of their clinical efficiency and desirable safety profile.
A double-disk diffusion test is a kind of disk diffusion test
