Gram-negative aerobic cocci of low virulence that colonize the nasopharynx and occasionally cause MENINGITIS; BACTEREMIA; EMPYEMA; PERICARDITIS; and PNEUMONIA.

A genus of gram-negative, aerobic bacteria occurring as rods (subgenus Moraxella) or cocci (subgenus Branhamella). Its organisms are parasitic on the mucous membranes of humans and other warm-blooded animals.

A family of gram-negative, parasitic bacteria including several important pathogens of man.

A genus of gram-negative, aerobic, coccoid bacteria whose organisms are part of the normal flora of the oropharynx, nasopharynx, and genitourinary tract. Some species are primary pathogens for humans.

Infections with bacteria of the family NEISSERIACEAE.

A species of gram-negative, aerobic bacteria that is most frequently isolated from bovine eyes in cases of infectious keratoconjunctivitis (KERATOCONJUNCTIVITIS, INFECTIOUS), but also occurs in unaffected eyes and the nasal cavity of cattle.

Infections with bacteria of the family MORAXELLACEAE.

A form of pneumoconiosis caused by inhalation of dust that contains both CARBON and crystalline SILICON DIOXIDE. These foreign matters induce fibrous nodule formation in the lung.

Invasion of the host RESPIRATORY SYSTEM by microorganisms, usually leading to pathological processes or diseases.

A species of HAEMOPHILUS found on the mucous membranes of humans and a variety of animals. The species is further divided into biotypes I through VIII.

Tracheitis is an inflammation of the trachea, often caused by viral or bacterial infections, characterized by symptoms such as cough, sore throat, and difficulty swallowing.

A semisynthetic cephamycin antibiotic with a broad spectrum of activity against both gram-positive and gram-negative microorganisms. It has a high rate of efficacy in many types of infection and to date no severe side effects have been noted.

Infections by bacteria, general or unspecified.

Enzymes found in many bacteria which catalyze the hydrolysis of the amide bond in the beta-lactam ring. Well known antibiotics destroyed by these enzymes are penicillins and cephalosporins.

Acids, salts, and derivatives of clavulanic acid (C8H9O5N). They consist of those beta-lactam compounds that differ from penicillin in having the sulfur of the thiazolidine ring replaced by an oxygen. They have limited antibacterial action, but block bacterial beta-lactamase irreversibly, so that similar antibiotics are not broken down by the bacterial enzymes and therefore can exert their antibacterial effects.

A semisynthetic cephalosporin antibiotic which can be administered intravenously or by suppository. The drug is highly resistant to a broad spectrum of beta-lactamases and is active against a wide range of both aerobic and anaerobic gram-positive and gram-negative organisms. It has few side effects and is reported to be safe and effective in aged patients and in patients with hematologic disorders.

A species of gram-negative, aerobic bacteria primarily found in purulent venereal discharges. It is the causative agent of GONORRHEA.

The study of the structure, growth, function, genetics, and reproduction of bacteria, and BACTERIAL INFECTIONS.

Substances that reduce the growth or reproduction of BACTERIA.

A pyrimidine inhibitor of dihydrofolate reductase, it is an antibacterial related to PYRIMETHAMINE. It is potentiated by SULFONAMIDES and the TRIMETHOPRIM, SULFAMETHOXAZOLE DRUG COMBINATION is the form most often used. It is sometimes used alone as an antimalarial. TRIMETHOPRIM RESISTANCE has been reported.

Any tests that demonstrate the relative efficacy of different chemotherapeutic agents against specific microorganisms (i.e., bacteria, fungi, viruses).

Semi-synthetic derivative of penicillin that functions as an orally active broad-spectrum antibiotic.

Infectious diseases of cattle, sheep, and goats, characterized by blepharospasm, lacrimation, conjunctivitis, and varying degrees of corneal opacity and ulceration. In cattle the causative agent is MORAXELLA (MORAXELLA) BOVIS; in sheep, MYCOPLASMA; RICKETTSIA; CHLAMYDIA; or ACHOLEPLASMA; in goats, RICKETTSIA.

Material coughed up from the lungs and expectorated via the mouth. It contains MUCUS, cellular debris, and microorganisms. It may also contain blood or pus.

Clavulanic acid and its salts and esters. The acid is a suicide inhibitor of bacterial beta-lactamase enzymes from Streptomyces clavuligerus. Administered alone, it has only weak antibacterial activity against most organisms, but given in combination with other beta-lactam antibiotics it prevents antibiotic inactivation by microbial lactamase.

A large group of aerobic bacteria which show up as pink (negative) when treated by the gram-staining method. This is because the cell walls of gram-negative bacteria are low in peptidoglycan and thus have low affinity for violet stain and high affinity for the pink dye safranine.

One of the three domains of life (the others being Eukarya and ARCHAEA), also called Eubacteria. They are unicellular prokaryotic microorganisms which generally possess rigid cell walls, multiply by cell division, and exhibit three principal forms: round or coccal, rodlike or bacillary, and spiral or spirochetal. Bacteria can be classified by their response to OXYGEN: aerobic, anaerobic, or facultatively anaerobic; by the mode by which they obtain their energy: chemotrophy (via chemical reaction) or PHOTOTROPHY (via light reaction); for chemotrophs by their source of chemical energy: CHEMOLITHOTROPHY (from inorganic compounds) or chemoorganotrophy (from organic compounds); and by their source for CARBON; NITROGEN; etc.; HETEROTROPHY (from organic sources) or AUTOTROPHY (from CARBON DIOXIDE). They can also be classified by whether or not they stain (based on the structure of their CELL WALLS) with CRYSTAL VIOLET dye: gram-negative or gram-positive.

A group of broad-spectrum antibiotics first isolated from the Mediterranean fungus ACREMONIUM. They contain the beta-lactam moiety thia-azabicyclo-octenecarboxylic acid also called 7-aminocephalosporanic acid.

Techniques used in studying bacteria.

A broad-spectrum semisynthetic antibiotic similar to AMPICILLIN except that its resistance to gastric acid permits higher serum levels with oral administration.

Proteins isolated from the outer membrane of Gram-negative bacteria.

Any liquid or solid preparation made specifically for the growth, storage, or transport of microorganisms or other types of cells. The variety of media that exist allow for the culturing of specific microorganisms and cell types, such as differential media, selective media, test media, and defined media. Solid media consist of liquid media that have been solidified with an agent such as AGAR or GELATIN.

Infections with bacteria of the genus HAEMOPHILUS.

A third-generation cephalosporin antibiotic that is stable to hydrolysis by beta-lactamases.

Inflammation of the MIDDLE EAR including the AUDITORY OSSICLES and the EUSTACHIAN TUBE.

A gram-positive organism found in the upper respiratory tract, inflammatory exudates, and various body fluids of normal and/or diseased humans and, rarely, domestic animals.

The top portion of the pharynx situated posterior to the nose and superior to the SOFT PALATE. The nasopharynx is the posterior extension of the nasal cavities and has a respiratory function.

Immunoglobulins produced in a response to BACTERIAL ANTIGENS.

Bacteria which lose crystal violet stain but are stained pink when treated by Gram's method.

Bacteria which retain the crystal violet stain when treated by Gram's method.

The ability of microorganisms, especially bacteria, to resist or to become tolerant to chemotherapeutic agents, antimicrobial agents, or antibiotics. This resistance may be acquired through gene mutation or foreign DNA in transmissible plasmids (R FACTORS).

A complex of proteins that forms a receptor for TRANSFERRIN in BACTERIA. Many pathogenic bacteria utilize the transferrin-binding complex to acquire their supply of iron from serum.

Deoxyribonucleic acid that makes up the genetic material of bacteria.

Compounds based on ERYTHROMYCIN with the 3-cladinose replaced by a ketone. They bind the 23S part of 70S bacterial RIBOSOMES.

Substances elaborated by bacteria that have antigenic activity.

A genus of the family Chinchillidae which consists of three species: C. brevicaudata, C. lanigera, and C. villidera. They are used extensively in biomedical research.