21.2 Bacterial Infections of the Skin and Eyes
3 min read•june 18, 2024
Bacteria can wreak havoc on our skin and eyes. From pesky to painful pink eye, these tiny troublemakers cause a range of infections. Understanding common culprits like and helps us recognize and treat these issues effectively.
Prevention is key in battling bacterial skin and eye infections. Good hygiene, proper wound care, and smart contact lens habits go a long way. When infections do occur, prompt treatment with appropriate antibiotics is crucial, especially given the growing challenge of antibiotic resistance.
Bacterial Pathogens and Infections of the Skin and Eyes
Common bacterial skin and eye pathogens
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- Staphylococcus species
- commonly causes skin infections (, , ) and eye infections (, )
- part of normal skin flora but can cause opportunistic infections
- Streptococcus species
- (Group A Streptococcus) causes , , and
- can cause and keratitis
- opportunistic pathogen infects wounds, burns, and causes keratitis and corneal ulcers especially in contact lens wearers
- Other notable pathogens
- causes by infecting and producing inflammation
- intracellular pathogen causes leading to blindness if untreated
- spp. and spp. can cause conjunctivitis especially in children
Symptoms and treatments of infections
- Impetigo
- Symptoms: red sores that rupture, ooze, and form honey-colored crusts
- Transmission: direct contact with lesions or contaminated items
- Treatment: topical or oral antibiotics (, )
- Cellulitis
- Symptoms: red, swollen, warm, and painful skin; fever and chills
- Transmission: breaks in the skin allowing bacteria to enter
- Treatment: oral or IV antibiotics (cephalexin, , )
- Conjunctivitis (pink eye)
- Symptoms: red, itchy, watery eyes; discharge; swollen eyelids
- Transmission: contact with infected secretions or contaminated objects
- Treatment: antibiotic eye drops or ointments (, )
-
- Symptoms: inflamed and irritated eyes, eyelid scarring, corneal opacity
- Transmission: direct contact with infected secretions or flies
- Treatment: oral or eye ointment
- Prevention strategies for skin and eye infections
- Practice good hygiene by washing hands and avoiding touching eyes or skin lesions
- Clean and cover wounds to prevent bacterial entry
- Avoid sharing personal items (towels, razors, eye makeup)
- Disinfect contact lenses and cases regularly; avoid wearing lenses while swimming
- Challenges in treatment
- Antibiotic resistance can make infections harder to treat
- Methicillin-resistant S. aureus () is resistant to many common antibiotics
- Misuse or overuse of antibiotics can select for resistant strains
- can complicate treatment in healthcare settings
- Antibiotic resistance can make infections harder to treat
Biofilms in antibiotic resistance
- are communities of bacteria encased in an extracellular matrix
- Matrix protects bacteria from antibiotics and host immune defenses
- Allows bacteria to adhere to surfaces (skin, medical devices, contact lenses)
- Bacteria in have altered gene expression and metabolic activity
- Slow-growing or dormant cells are less susceptible to antibiotics
- Horizontal gene transfer can spread antibiotic resistance genes
- Biofilms enable chronic and recurrent infections
- P. aeruginosa biofilms in wounds and on contact lenses
- S. aureus biofilms in chronic wounds and medical device-related infections
- Strategies to combat biofilms
- Combination therapy using multiple antibiotics with different mechanisms of action
- Use of anti-biofilm agents (enzymes, chelators, inhibitors)
- Disrupt biofilm matrix, interfere with bacterial communication and attachment
- Physical removal of biofilms through or device removal
- Development of new antibiotics and alternative therapies that target biofilms
Bacterial virulence factors and host immune response
- enhance pathogenicity
- Adhesins for attachment to host cells
- Toxins that damage host tissues
- Enzymes that break down host defenses
- to bacterial infections
- Innate immunity: inflammation, phagocytosis, complement activation
- Adaptive immunity: antibody production, T-cell responses
- in skin and eye pathogens
- Enzymatic inactivation of antibiotics
- Altered antibiotic target sites
- Efflux pumps to remove antibiotics from bacterial cells
Key Terms to Review (139)
Acne: Acne is a common skin condition characterized by the inflammation of hair follicles and sebaceous glands, often caused by the bacterium Propionibacterium acnes. It manifests as pimples, blackheads, and cysts primarily on the face, neck, chest, and back.
Acne Vulgaris: Acne vulgaris is a common skin condition characterized by the development of pimples, blackheads, and other blemishes on the face, chest, and back. It is caused by a combination of factors, including overproduction of oil, clogged pores, and bacterial infection.
Acute glomerulonephritis: Acute glomerulonephritis is a rapid-onset inflammation of the glomeruli in the kidneys. It is often caused by immune responses to infections, including bacterial infections.
Aeromonas hydrophila: Aeromonas hydrophila is a Gram-negative, rod-shaped bacterium commonly found in freshwater environments. It can cause infections in the skin, eyes, and gastrointestinal tract.
Agglutination reactions: Agglutination reactions are immunological tests where particles (such as bacteria or red blood cells) clump together due to the binding of antibodies. These reactions are used for detecting and identifying antigens or antibodies in a sample.
AGN: Acute Glomerulonephritis (AGN) is a rapid-onset inflammation of the glomeruli in the kidneys, which can be triggered by bacterial skin and eye infections. It often results from immune responses to infections such as Streptococcus.
Anthrax: Anthrax is a serious infectious disease caused by the bacterium Bacillus anthracis. It primarily affects livestock but can also infect humans through contact with contaminated animal products.
Anthrax vaccine: The anthrax vaccine is a medical preparation designed to provide immunity against Bacillus anthracis, the bacterium that causes anthrax. It is primarily used for individuals at high risk of exposure to the bacteria.
Antibiotic Resistance Mechanisms: Antibiotic resistance mechanisms refer to the various ways in which bacteria can develop the ability to withstand and survive the effects of antibiotics, rendering these antimicrobial drugs ineffective. Understanding these mechanisms is crucial in the context of bacterial infections of the skin and eyes, as they can impact treatment strategies and patient outcomes.
Azithromycin: Azithromycin is a broad-spectrum macrolide antibiotic effective against a variety of bacterial infections. It works by inhibiting bacterial protein synthesis.
Azithromycin: Azithromycin is a macrolide antibiotic that is widely used to treat a variety of bacterial infections. It is known for its unique pharmacokinetic properties, broad spectrum of activity, and effectiveness against common pathogens.
Bacillus anthracis: Bacillus anthracis is a gram-positive, rod-shaped bacterium that causes anthrax. It is known for its ability to form resilient spores that can survive in harsh environments.
Bacterial keratitis: Bacterial keratitis is a severe inflammation of the cornea caused by bacterial infection. It often results in pain, redness, and potential vision loss if untreated.
Bacterial Virulence Factors: Bacterial virulence factors are specific molecules or characteristics that enable pathogenic bacteria to infect, colonize, and cause harm to their host. These factors contribute to the ability of bacteria to evade the host's immune defenses, adhere to and invade host cells, and produce toxins or other damaging substances.
Benzoyl peroxide: Benzoyl peroxide is an antimicrobial agent commonly used in the treatment of acne. It works by killing bacteria on the skin and reducing inflammation.
Biofilms: Biofilms are complex communities of microorganisms that adhere to surfaces and are embedded within a self-produced matrix of extracellular polymeric substances. They provide protection to the bacteria from environmental stresses and antimicrobial agents.
Biofilms: Biofilms are complex communities of microorganisms, primarily bacteria, that adhere to surfaces and are encased in a self-produced extracellular matrix. These microbial communities exhibit unique characteristics and behaviors that distinguish them from free-floating, planktonic microbes.
Bioterrorism: Bioterrorism involves the intentional release of harmful biological agents such as bacteria, viruses, or toxins to cause illness or death in people, animals, or plants. It is a significant threat due to its potential for mass casualties and disruption.
Bullae: Bullae are large, fluid-filled blisters that form on the skin due to various infections or conditions. They are typically larger than 0.5 cm in diameter and can be caused by bacterial infections such as Staphylococcus aureus.
CA-MRSA: CA-MRSA is a strain of Methicillin-resistant Staphylococcus aureus that occurs in healthy individuals outside of healthcare settings. It causes skin infections and can be more virulent than hospital-associated MRSA.
Carbuncle: A carbuncle is a cluster of connected furuncles (boils) caused by bacterial infection, typically Staphylococcus aureus. It results in deep skin abscesses that can lead to severe pain and systemic symptoms.
Carbuncles: Carbuncles are clusters of boils caused by bacterial infection, commonly by Staphylococcus aureus. They are deeper and more severe than single boils and can cause significant discomfort and systemic symptoms.
Carter Center: The Carter Center is a non-profit organization dedicated to improving global health and resolving conflicts. Founded by former U.S. President Jimmy Carter and his wife Rosalynn, it focuses on disease eradication and prevention.
Catalase test: The catalase test is a biochemical test used to identify organisms that produce the enzyme catalase. Catalase breaks down hydrogen peroxide into water and oxygen, making it essential for protecting cells from oxidative damage.
Cellulitis: Cellulitis is a bacterial infection of the skin and subcutaneous tissues characterized by redness, swelling, warmth, and pain. It commonly affects the lower legs but can occur anywhere on the body.
Cellulitis: Cellulitis is a potentially serious bacterial skin infection that typically occurs when bacteria, often Streptococcus or Staphylococcus, enter the skin through a cut, scratch, or other break in the skin. It can cause redness, swelling, warmth, and pain in the affected area, and if left untreated, can spread to the bloodstream and other tissues.
This term is particularly relevant to the topics of 21.1 Anatomy and Normal Microbiota of the Skin and Eyes, 21.2 Bacterial Infections of the Skin and Eyes, and 25.1 Anatomy of the Circulatory and Lymphatic Systems, as cellulitis involves the skin, eyes, and can spread through the circulatory and lymphatic systems.
Cephalexin: Cephalexin is a first-generation cephalosporin antibiotic used to treat a variety of bacterial infections, particularly those affecting the skin and eyes. As a broad-spectrum antibiotic, it is effective against both Gram-positive and Gram-negative bacteria, making it a common choice for treating common skin and eye infections.
Cetrimide agar: Cetrimide agar is a selective medium used for the isolation and identification of Pseudomonas aeruginosa, a common pathogen in skin and eye infections. It contains cetrimide, which inhibits the growth of other bacteria while promoting the production of characteristic pigments by Pseudomonas aeruginosa.
Chlamydia trachomatis: Chlamydia trachomatis is a species of obligate intracellular bacteria that is the causative agent of several human diseases, including trachoma, lymphogranuloma venereum, and various sexually transmitted infections. It is a significant public health concern due to its ability to infect and impact multiple body systems.
Ciprofloxacin: Ciprofloxacin is a broad-spectrum antibiotic belonging to the fluoroquinolone class, effective against various bacterial infections. It operates by inhibiting DNA gyrase and topoisomerase IV, enzymes crucial for bacterial DNA replication.
Ciprofloxacin: Ciprofloxacin is a broad-spectrum fluoroquinolone antibiotic used to treat a variety of bacterial infections. It works by inhibiting the DNA gyrase and topoisomerase IV enzymes, which are essential for bacterial DNA replication and transcription, ultimately leading to cell death. Ciprofloxacin has been widely used in the treatment of infections since its development and approval in the 1980s.
Clostridium: Clostridium is a genus of Gram-positive, anaerobic, spore-forming bacteria. They are known for their role in various human diseases and environmental processes.
Coagulase: Coagulase is an enzyme produced by certain bacteria that enables the conversion of fibrinogen to fibrin, leading to blood clot formation. It is a virulence factor that helps these bacteria evade immune responses.
Comedones: Comedones are clogged hair follicles (pores) in the skin, which can be open (blackheads) or closed (whiteheads). They are commonly associated with acne and result from a combination of excessive sebum production and buildup of dead skin cells.
Community-acquired MRSA: Community-acquired MRSA (CA-MRSA) is a strain of methicillin-resistant Staphylococcus aureus that occurs in healthy individuals who have not been hospitalized or had medical procedures within the past year. It is known for causing skin and soft tissue infections.
Conjunctivitis: Conjunctivitis, commonly known as pink eye, is an inflammation or infection of the conjunctiva, the transparent membrane that lines your eyelid and covers the white part of your eyeball. It can be caused by bacteria, viruses, allergens, or irritants.
Conjunctivitis: Conjunctivitis is an inflammation or infection of the conjunctiva, the transparent membrane that covers the white part of the eye and the inner surface of the eyelids. It can be caused by various factors, including bacterial or viral infections, allergies, and irritants, and is commonly known as 'pink eye.'
Debridement: Debridement is the medical removal of dead, damaged, or infected tissue to improve the healing potential of the remaining healthy tissue. It is often used in treating severe skin and eye bacterial infections.
Dicloxacillin: Dicloxacillin is a semi-synthetic penicillin antibiotic used to treat bacterial infections, particularly those caused by Staphylococcus aureus. It is commonly prescribed for skin and eye infections due to its effectiveness against gram-positive bacteria.
ELISA: ELISA (Enzyme-Linked Immunosorbent Assay) is a technique used to detect the presence of antibodies or antigens in a sample. It is widely used in microbiology for diagnostics and research.
Erysipelas: Erysipelas is a bacterial skin infection caused primarily by Streptococcus pyogenes, characterized by raised, red, and swollen patches on the skin. It often affects the face and legs and can be accompanied by fever and chills.
Erysipelas: Erysipelas is a potentially serious bacterial skin infection caused by Streptococcus pyogenes, also known as group A Streptococcus. It is characterized by a rapidly spreading, red, swollen, and painful rash on the skin, often with a distinct border.
Erythema: Erythema is the medical term for redness of the skin or mucous membranes caused by increased blood flow in superficial capillaries. It often presents as a primary response to infection, inflammation, or irritation.
Erythema nodosum: Erythema nodosum is an inflammatory condition characterized by painful, red nodules typically found on the shins. It is often associated with bacterial infections and can be a sign of underlying systemic disease.
Erythromycin: Erythromycin is a macrolide antibiotic that inhibits bacterial protein synthesis by binding to the 50S ribosomal subunit. It is effective against a wide range of Gram-positive and some Gram-negative bacteria.
Erythromycin: Erythromycin is a macrolide antibiotic that is commonly used to treat a variety of bacterial infections. It works by inhibiting bacterial protein synthesis, making it an effective tool in the management of both Gram-positive and some Gram-negative bacterial infections.
Eschar: Eschar is a dry, dark scab or falling away of dead skin, typically caused by a burn or infection. It commonly appears in bacterial infections such as anthrax and can be a sign of necrotizing tissue.
Escherichia coli: Escherichia coli (E. coli) is a Gram-negative, rod-shaped bacterium commonly found in the intestines of warm-blooded organisms. While most strains are harmless, some can cause serious food poisoning and infections.
Exoenzyme S: Exoenzyme S is a virulence factor produced by Pseudomonas aeruginosa. It disrupts host cell function by ADP-ribosylation of various cellular proteins.
Exotoxin A: Exotoxin A is a potent toxin produced by Pseudomonas aeruginosa. It disrupts protein synthesis in host cells, leading to cell death.
Fimbriae: Fimbriae are hair-like appendages present on the surface of many bacteria, primarily involved in adhesion to surfaces and other cells. They play a significant role in bacterial colonization and virulence.
Flesh-eating bacterial syndrome: Flesh-eating bacterial syndrome, also known as necrotizing fasciitis, is a severe infection that rapidly destroys muscles, fat, and skin tissue. It is typically caused by bacteria such as Group A Streptococcus.
Folliculitis: Folliculitis is an inflammation of the hair follicles commonly caused by bacterial infection, particularly Staphylococcus aureus. It often manifests as red, swollen, and pus-filled bumps on the skin.
Folliculitis: Folliculitis is a common skin condition characterized by inflammation of the hair follicles, often resulting in small, red, and sometimes pus-filled bumps on the skin. It can occur in various parts of the body, particularly areas with a high density of hair follicles.
Furuncle: A furuncle, also known as a boil, is a painful, pus-filled bump under the skin caused by bacterial infection, typically Staphylococcus aureus. They develop when bacteria infect hair follicles or oil glands.
Furuncles: Furuncles, also known as boils, are painful, pus-filled bumps that form under the skin due to bacterial infection of hair follicles. They are commonly caused by Staphylococcus aureus.
Gastrointestinal anthrax: Gastrointestinal anthrax is an infection caused by ingesting Bacillus anthracis spores, leading to severe gastrointestinal symptoms. It is a rare but serious disease that can be fatal without prompt treatment.
Granular conjunctivitis: Granular conjunctivitis, also known as trachoma, is a chronic infectious disease of the eye caused by the bacterium Chlamydia trachomatis. It leads to the formation of granules on the inner surface of the eyelids and can result in blindness if untreated.
Group A streptococcus (GAS): Group A Streptococcus (GAS) is a bacterium commonly found in the throat and on the skin. It can cause a range of infections, from minor illnesses to severe diseases.
HA-MRSA: HA-MRSA (Healthcare-Associated Methicillin-Resistant Staphylococcus aureus) is a type of bacterial infection resistant to many antibiotics, commonly acquired in healthcare settings. It often leads to severe skin and soft tissue infections among hospitalized patients.
Haemophilus: Haemophilus is a genus of Gram-negative, coccobacillary bacteria that are known to cause various infections, including those affecting the skin and eyes. These bacteria are obligate aerobes and require specific growth factors, such as hemin and nicotinamide adenine dinucleotide (NAD), for their survival and proliferation.
Haemophilus influenzae: Haemophilus influenzae is a Gram-negative bacterium that can cause various infections, particularly in the respiratory tract. It is known for causing severe diseases such as meningitis and pneumonia, especially in young children and immunocompromised individuals.
Hair follicles: Hair follicles are tubular structures in the skin from which hair grows. They play a crucial role in housing and protecting various microorganisms that form part of the skin's normal microbiota.
Hospital-acquired MRSA: Hospital-acquired MRSA (Methicillin-resistant Staphylococcus aureus) is a type of bacterial infection resistant to many antibiotics, particularly contracted in healthcare settings. It primarily affects patients with weakened immune systems or those undergoing invasive procedures.
Host Immune Response: The host immune response refers to the complex system of biological mechanisms and processes by which the human body recognizes and defends itself against harmful pathogens, such as bacteria, viruses, fungi, and parasites. This response is crucial in maintaining health and preventing the development of infectious diseases.
Hot tub rash: Hot tub rash, also known as Pseudomonas dermatitis, is a skin infection caused by the bacterium Pseudomonas aeruginosa. It typically occurs after exposure to contaminated water in hot tubs or swimming pools.
Hyaluronidase: Hyaluronidase is an enzyme that breaks down hyaluronic acid, a component of the extracellular matrix. This activity facilitates the spread of pathogens through tissues.
Impetigo: Impetigo is a highly contagious bacterial skin infection characterized by red sores and blisters, primarily caused by Staphylococcus aureus and Streptococcus pyogenes. It commonly affects infants and young children but can occur in individuals of any age.
Impetigo: Impetigo is a highly contagious bacterial skin infection caused by Staphylococcus or Streptococcus bacteria. It is characterized by the development of red sores, blisters, and crusty lesions, typically on the face, hands, and other exposed areas of the body.
Inclusion conjunctivitis: Inclusion conjunctivitis is an eye infection caused by the bacterium Chlamydia trachomatis. It primarily affects the conjunctiva, leading to inflammation and discharge.
Inhalation anthrax: Inhalation anthrax is a severe bacterial infection caused by inhaling Bacillus anthracis spores. It primarily affects the lungs and can be fatal if not treated promptly.
Injection anthrax: Injection anthrax is a serious bacterial infection caused by Bacillus anthracis, introduced into the body via injection. It presents rapidly and can lead to severe systemic symptoms.
Isotretinoin: Isotretinoin is a powerful retinoid medication primarily used to treat severe acne. It works by reducing sebaceous gland activity and has significant anti-inflammatory effects.
Keratitis: Keratitis is an inflammation of the cornea, the transparent, dome-shaped structure at the front of the eye. It can be caused by various factors, including bacterial infections, viral infections, fungal infections, trauma, or underlying medical conditions, and can lead to vision problems if left untreated.
Lancefield groups: Lancefield groups are a classification system for streptococci based on the carbohydrate composition of their cell wall antigens. Developed by Rebecca Lancefield, these groups help in identifying and differentiating pathogenic streptococci.
Leukocidins: Leukocidins are toxins produced by certain bacteria that kill white blood cells, thereby weakening the host's immune response. They are important virulence factors in many pathogenic bacteria.
M protein: M protein is a virulence factor found on the surface of certain bacteria, notably Streptococcus pyogenes. It plays a crucial role in evading the host immune response by inhibiting phagocytosis.
Mannitol salt agar (MSA): Mannitol Salt Agar (MSA) is a selective and differential culture medium used primarily for the isolation of Staphylococcus species. It contains a high concentration of salt, mannitol, and a pH indicator to differentiate between mannitol fermenters and non-fermenters.
Minocycline: Minocycline is a broad-spectrum tetracycline antibiotic used to treat various bacterial infections, including those of the skin and eyes. It works by inhibiting bacterial protein synthesis, thereby preventing bacterial growth.
Moraxella: Moraxella is a genus of Gram-negative, aerobic bacteria that are known to cause various infections, particularly in the skin and eyes. These opportunistic pathogens are commonly found in the upper respiratory tract and can lead to conditions like conjunctivitis, keratitis, and skin infections.
MRSA: MRSA (Methicillin-resistant Staphylococcus aureus) is a type of Gram-positive bacterium that is resistant to several widely used antibiotics, making it difficult to treat. It commonly causes skin and soft tissue infections but can lead to more severe invasive diseases.
Mupirocin: Mupirocin is a topical antibiotic medication primarily used to treat bacterial skin infections. It is effective against a wide range of gram-positive bacteria, including Staphylococcus aureus, and is commonly used to prevent and treat conditions like impetigo, folliculitis, and other skin infections.
Necrotizing fasciitis: Necrotizing fasciitis is a severe bacterial infection that destroys skin, fat, and tissue covering the muscles. It spreads rapidly and requires prompt medical intervention.
Neisseria gonorrhoeae: Neisseria gonorrhoeae is a gram-negative diplococcus bacterium responsible for the sexually transmitted infection gonorrhea. It primarily infects the urogenital tract but can also affect the eyes, throat, and joints.
Neonatal conjunctivitis: Neonatal conjunctivitis, also known as ophthalmia neonatorum, is an eye infection occurring in newborns typically within the first month of life. It can be caused by bacteria or viruses acquired during delivery.
Nodules: Nodules are small, raised areas or lumps that can form on the skin due to infections, inflammation, or other causes. In microbiology, they are often associated with certain bacterial and fungal infections.
Noncutaneous anthrax: Noncutaneous anthrax is a form of anthrax infection that does not involve the skin, typically affecting the respiratory or gastrointestinal systems. It is caused by inhalation or ingestion of Bacillus anthracis spores, leading to severe and often fatal systemic illness.
Nosocomial Infections: Nosocomial infections, also known as hospital-acquired infections, are infections that patients develop while receiving treatment in a healthcare facility. These infections are not present or incubating at the time of admission and can have significant implications for patient health and healthcare costs.
Ophthalmia neonatorum: Ophthalmia neonatorum is a severe form of conjunctivitis occurring in newborns, typically caused by bacterial infection acquired during childbirth. It can lead to blindness if not treated promptly.
Opportunistic pathogens: Opportunistic pathogens are microorganisms that cause disease primarily in hosts with weakened immune systems. They typically do not cause illness in healthy individuals with intact immune defenses.
Opportunistic Pathogens: Opportunistic pathogens are microorganisms that typically do not cause disease in healthy individuals, but can take advantage of a compromised immune system or a disruption in the normal microbiota to cause infection. These pathogens become a concern in the context of the skin, eyes, and other body sites where the normal microbiota plays a critical role in maintaining health.
Otitis externa: Otitis externa, commonly known as swimmer's ear, is an infection of the outer ear canal. It is often caused by bacterial infection and can result in pain, swelling, and redness.
Papules: Papules are small, raised, solid pimples or swellings on the skin that do not contain pus. They are often caused by inflammation or infection and can be a sign of various skin conditions.
Penicillin: Penicillin is a group of antibiotics derived from Penicillium fungi. It is widely used to treat bacterial infections by inhibiting cell wall synthesis.
Pharyngitis: Pharyngitis is the inflammation of the pharynx, causing a sore throat. It can be caused by viral or bacterial infections.
Phospholipase C: Phospholipase C is an enzyme that hydrolyzes phospholipids into diacylglycerol and inositol trisphosphate. It plays a key role in cell signaling pathways and can be a virulence factor for certain bacteria.
Pimples: Pimples are small, inflamed spots on the skin caused by clogged hair follicles, often due to bacteria, dead skin cells, and oil buildup. They are a common symptom of bacterial skin infections.
Pinkeye: Pinkeye, or conjunctivitis, is an inflammation of the conjunctiva caused by bacterial, viral, or allergic agents. It results in redness, swelling, and discharge from the eye.
Polymyxin B: Polymyxin B is an antibiotic primarily used to treat Gram-negative bacterial infections. It disrupts the bacterial cell membrane, leading to cell death.
Porins: Porins are protein channels located in the outer membrane of Gram-negative bacteria. They allow the passive diffusion of small molecules, including nutrients and waste products.
Propionibacterium acnes: Propionibacterium acnes is an anaerobic, gram-positive bacterium that is a common inhabitant of the human skin and is associated with the development of acne. It plays a significant role in the normal microbiota of the skin and eyes, as well as in bacterial infections affecting these areas.
Pseudomonas aeruginosa: Pseudomonas aeruginosa is a Gram-negative, opportunistic pathogen that can cause serious infections in humans. It is known for its resistance to antibiotics and ability to thrive in various environments.
Pulmonary anthrax: Pulmonary anthrax is a severe bacterial infection caused by inhaling Bacillus anthracis spores. It primarily affects the lungs and can be fatal if not treated promptly.
Purulent: Purulent describes a condition characterized by the presence of pus, which is a thick fluid composed of white blood cells, dead tissue, and bacteria. It commonly indicates an infection.
Pustules: Pustules are small, inflamed, pus-filled lesions on the skin that typically result from bacterial infections. They are often associated with conditions like acne and impetigo.
Pyocyanin: Pyocyanin is a blue-green pigment produced by the bacterium Pseudomonas aeruginosa. It plays a role in the pathogenicity of infections, particularly those affecting skin and eyes.
Pyoderma: Pyoderma is a bacterial skin infection characterized by the presence of pus. It commonly results from the invasion of bacteria into hair follicles, sweat glands, or broken skin.
Pyoverdin: Pyoverdin is a fluorescent siderophore produced by Pseudomonas aeruginosa. It plays a critical role in iron acquisition and virulence.
Quorum Sensing: Quorum sensing is a communication mechanism used by bacteria to coordinate gene expression and behavior in response to changes in cell population density. It allows bacteria to sense and respond to the presence of other bacteria, enabling them to act in a coordinated manner as a community rather than as individual cells.
Retinoids: Retinoids are a class of chemical compounds derived from vitamin A, used primarily in dermatology to treat various skin conditions. They are known for their ability to regulate epithelial cell growth and have antimicrobial properties.
S. aureus: S. aureus, or Staphylococcus aureus, is a Gram-positive bacterium known for its ability to cause a wide range of infections, from mild skin conditions to life-threatening diseases. This versatile pathogen is a significant concern in both healthcare and community settings due to its virulence factors and potential for antibiotic resistance.
S. aureus is a key topic in the context of Gram-positive bacteria, biochemical identification of microorganisms, and bacterial infections of the skin and eyes. Its unique characteristics and clinical significance make it an important subject of study for students of microbiology.
S. epidermidis: S. epidermidis is a type of Gram-positive bacterium that commonly resides on the human skin and mucous membranes. It is a member of the Staphylococcus genus and is considered part of the normal human microbiome, playing a role in maintaining skin health and preventing the colonization of more harmful pathogens.
S. pneumoniae: S. pneumoniae, also known as Streptococcus pneumoniae, is a Gram-positive bacterium that is a leading cause of serious infections, particularly in the skin and eyes. It is a common colonizer of the upper respiratory tract and can cause a wide range of diseases, from mild skin infections to life-threatening pneumonia and meningitis.
S. pyogenes: S. pyogenes, also known as Streptococcus pyogenes, is a Gram-positive bacterium that is a common cause of skin and soft tissue infections, as well as more serious invasive diseases. It is a significant pathogen that can lead to a range of clinical manifestations, from mild skin infections to life-threatening conditions.
SAFE initiative: The SAFE initiative is a public health strategy aimed at controlling and eliminating bacterial infections affecting the skin and eyes, particularly trachoma. It involves Surgery, Antibiotics, Facial cleanliness, and Environmental improvement.
Salicylic acid: Salicylic acid is a beta hydroxy acid that is commonly used in the treatment of skin conditions, especially acne. It has keratolytic properties, helping to exfoliate the skin and reduce inflammation.
Scarlet fever: Scarlet fever is an infectious disease caused by the bacterium Streptococcus pyogenes, characterized by a red rash and high fever. It primarily affects children and can have serious complications if untreated.
Siderophores: Siderophores are small, high-affinity iron-chelating compounds secreted by bacteria and fungi to sequester iron from their environment. They play a crucial role in microbial survival and pathogenicity, especially in iron-limited environments like the human body.
Staphylococcal scalded skin syndrome (SSSS): Staphylococcal scalded skin syndrome (SSSS) is a severe skin infection caused by Staphylococcus aureus, characterized by widespread redness, blisters, and peeling skin. It primarily affects infants and young children.
Staphylococcus: Staphylococcus is a genus of Gram-positive bacteria known for their spherical shape and tendency to form clusters resembling grapes. They are commonly found on the skin and in the nasal passages of humans.
Staphylolysins: Staphylolysins are exotoxins produced by staphylococcal bacteria that lyse red blood cells and other cell types. They play a significant role in the pathogenicity of staphylococcal infections by damaging host tissues.
Streptococcus: Streptococcus is a genus of Gram-positive bacteria that often occur in chains or pairs. They are known for causing a variety of infections in humans, ranging from mild throat infections to life-threatening diseases.
Streptococcus pyogenes: Streptococcus pyogenes is a Gram-positive bacterium responsible for various infections in humans. It is known for causing diseases such as strep throat, scarlet fever, and rheumatic fever.
Streptokinase: Streptokinase is an enzyme produced by certain strains of streptococci bacteria. It functions by breaking down blood clots through the conversion of plasminogen to plasmin.
Streptolysins: Streptolysins are hemolytic exotoxins produced by Streptococcus bacteria that can destroy red and white blood cells. They play a significant role in the pathogenicity of streptococcal infections.
Suppurative: Suppurative refers to the production or discharge of pus, commonly in response to bacterial infection. It is a characteristic feature of many skin and eye infections.
Swimmer’s ear: Swimmer’s ear, or otitis externa, is an infection of the outer ear canal caused by bacteria. It often results from water remaining in the ear after swimming, which creates a moist environment conducive to bacterial growth.
Tetracycline: Tetracycline is a broad-spectrum antibiotic used to treat a wide variety of bacterial infections. It works by inhibiting protein synthesis in bacteria, preventing them from growing and multiplying.
Tetracycline: Tetracycline is a broad-spectrum antibiotic that inhibits bacterial protein synthesis, making it effective against a wide range of Gram-positive and Gram-negative bacteria. It is particularly relevant in the context of Gram-positive bacteria and bacterial infections of the skin and eyes.
TMP/SMZ: TMP/SMZ, also known as Trimethoprim/Sulfamethoxazole, is a combination antibiotic used to treat various bacterial infections. It inhibits bacterial synthesis of folic acid, essential for DNA replication and cell survival.
Toxic shock syndrome toxin-1: Toxic Shock Syndrome Toxin-1 (TSST-1) is a superantigen produced by certain strains of Staphylococcus aureus. It is associated with toxic shock syndrome, a life-threatening condition characterized by high fever, rash, and multi-organ failure.
Trachoma: Trachoma is a bacterial infection of the eye caused by Chlamydia trachomatis, leading to inflammation and possible blindness if untreated. It is a significant cause of preventable blindness worldwide.
Trachoma: Trachoma is a chronic, contagious eye infection caused by the bacterium Chlamydia trachomatis. It is the leading infectious cause of blindness worldwide, primarily affecting individuals in developing countries with poor sanitation and limited access to healthcare.
Trichiasis: Trichiasis is a condition where eyelashes grow inward towards the eye, causing irritation and potential damage to the cornea. It is often associated with bacterial infections or chronic inflammation of the eyelid.
Trimethoprim-sulfamethoxazole: Trimethoprim-sulfamethoxazole is a combination antibiotic used to treat a variety of bacterial infections. It inhibits successive steps in the bacterial folate synthesis pathway, making it particularly effective against certain strains.
Vancomycin: Vancomycin is a glycopeptide antibiotic used to treat serious bacterial infections caused by Gram-positive bacteria. It inhibits cell wall synthesis by binding to the D-alanyl-D-alanine terminus of cell wall precursor units.
Vancomycin: Vancomycin is a glycopeptide antibiotic used to treat severe bacterial infections, particularly those caused by Gram-positive bacteria that are resistant to other antibiotics. It is an important tool in the fight against antimicrobial resistance and is a key consideration across various topics in microbiology and infectious disease management.
Wool sorter’s disease: Wool sorter's disease, also known as pulmonary anthrax, is a bacterial infection caused by Bacillus anthracis. It typically affects individuals who handle animal products such as wool and can lead to severe respiratory issues.
β-lactamases: β-lactamases are enzymes produced by bacteria that hydrolyze the β-lactam ring of β-lactam antibiotics, rendering them ineffective. They are a major mechanism of bacterial resistance to these drugs.