Gram-negative bacteriaGram-negative bacteria are bacteria that do not retain the crystal violet stain used in the Gram staining method of bacterial differentiation. They are characterized by their cell envelopes, which are composed of a thin peptidoglycan cell wall sandwiched between an inner cytoplasmic cell membrane and a bacterial outer membrane. Gram-negative bacteria are found in virtually all environments on Earth that support life.
MeningitisMeningitis is acute or chronic inflammation of the protective membranes covering the brain and spinal cord, collectively called the meninges. The most common symptoms are fever, headache, and neck stiffness. Other symptoms include confusion or altered consciousness, nausea, vomiting, and an inability to tolerate light or loud noises. Young children often exhibit only nonspecific symptoms, such as irritability, drowsiness, or poor feeding. A non-blanching rash (a rash that does not fade when a glass is rolled over it) may also be present.
DoxycyclineDoxycycline is a broad-spectrum antibiotic of the tetracycline class used in the treatment of infections caused by bacteria and certain parasites. It is used to treat bacterial pneumonia, acne, chlamydia infections, Lyme disease, cholera, typhus, and syphilis. It is also used to prevent malaria in combination with quinine. Doxycycline may be taken by mouth or by injection into a vein. Common side effects include diarrhea, nausea, vomiting, abdominal pain, and an increased risk of sunburn.
InfectionAn infection is the invasion of tissues by pathogens, their multiplication, and the reaction of host tissues to the infectious agent and the toxins they produce. An infectious disease, also known as a transmissible disease or communicable disease, is an illness resulting from an infection. Infections can be caused by a wide range of pathogens, most prominently bacteria and viruses. Hosts can fight infections using their immune systems. Mammalian hosts react to infections with an innate response, often involving inflammation, followed by an adaptive response.
AmoxicillinAmoxicillin is an antibiotic medication belonging to the aminopenicillin class of the penicillin family. The drug is used to treat bacterial infections such as middle ear infection, strep throat, pneumonia, skin infections, odontogenic infections, and urinary tract infections. It is taken by mouth, or less commonly by injection. Common adverse effects include nausea and rash. It may also increase the risk of yeast infections and, when used in combination with clavulanic acid, diarrhea.
PneumoniaPneumonia is an inflammatory condition of the lung primarily affecting the small air sacs known as alveoli. Symptoms typically include some combination of productive or dry cough, chest pain, fever, and difficulty breathing. The severity of the condition is variable. Pneumonia is usually caused by infection with viruses or bacteria, and less commonly by other microorganisms. Identifying the responsible pathogen can be difficult. Diagnosis is often based on symptoms and physical examination.
CellulitisCellulitis is usually a bacterial infection involving the inner layers of the skin. It specifically affects the dermis and subcutaneous fat. Signs and symptoms include an area of redness which increases in size over a few days. The borders of the area of redness are generally not sharp and the skin may be swollen. While the redness often turns white when pressure is applied, this is not always the case. The area of infection is usually painful. Lymphatic vessels may occasionally be involved, and the person may have a fever and feel tired.
AntibioticAn antibiotic is a type of antimicrobial substance active against bacteria. It is the most important type of antibacterial agent for fighting bacterial infections, and antibiotic medications are widely used in the treatment and prevention of such infections. They may either kill or inhibit the growth of bacteria. A limited number of antibiotics also possess antiprotozoal activity. Antibiotics are not effective against viruses such as the common cold or influenza; drugs which inhibit growth of viruses are termed antiviral drugs or antivirals rather than antibiotics.
Streptococcus pyogenesStreptococcus pyogenes is a species of Gram-positive, aerotolerant bacteria in the genus Streptococcus. These bacteria are extracellular, and made up of non-motile and non-sporing cocci (round cells) that tend to link in chains. They are clinically important for humans, as they are an infrequent, but usually pathogenic, part of the skin microbiota that can cause Group A streptococcal infection. S. pyogenes is the predominant species harboring the Lancefield group A antigen, and is often called group A Streptococcus (GAS).
Streptococcus pneumoniaeStreptococcus pneumoniae, or pneumococcus, is a Gram-positive, spherical bacteria, alpha-hemolytic 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. Streptococcus pneumoniae resides asymptomatically in healthy carriers typically colonizing the respiratory tract, sinuses, and nasal cavity.
