Pseudomonas is a non-lactose-fermenting, gram-negative bacillusBacillusBacillus are aerobic, spore-forming, gram-positive bacilli. Two pathogenic species are Bacillus anthracis (B. anthracis) and B. cereus. Bacillus that produces pyocyanin, which gives it a characteristic blue-green color. Pseudomonas is found ubiquitously in the environment, as well as in moist reservoirs, such as hospital sinks and respiratory equipment. Pseudomonas has a sweet, grape-like odor. The most clinically relevant species is Pseudomonas aeruginosa (P. aeruginosa), which has a wide array of clinical manifestations from benignBenignFibroadenoma diseases, such as swimmer’s earSwimmer’s earOtitis exteRNA (also known as external otitis or swimmer's ear) is an infection of the external auditory canal that is most often caused by acute bacterial infection and is frequently associated with hot, humid weather and water exposure. Patients commonly present with ear pain, pruritus, discharge, and hearing loss.Otitis Externa and “hot tub” folliculitis, to disseminated bacteremiaBacteremiaThe presence of viable bacteria circulating in the blood. Fever, chills, tachycardia, and tachypnea are common acute manifestations of bacteremia. The majority of cases are seen in already hospitalized patients, most of whom have underlying diseases or procedures which render their bloodstreams susceptible to invasion.Glycopeptides and osteomyelitisOsteomyelitisOsteomyelitis is an infection of the bone that results from the spread of microorganisms from the blood (hematogenous), nearby infected tissue, or open wounds (non-hematogenous). Infections are most commonly caused by Staphylococcus aureus.Osteomyelitis. Risk factors for infectionsInfectionsInvasion of the host organism by microorganisms or their toxins or by parasites that can cause pathological conditions or diseases.Chronic Granulomatous Disease include: neutropeniaNeutropeniaNeutrophils are an important component of the immune system and play a significant role in the eradication of infections. Low numbers of circulating neutrophils, referred to as neutropenia, predispose the body to recurrent infections or sepsis, though patients can also be asymptomatic. Neutropenia, cysticCysticFibrocystic ChangefibrosisFibrosisAny pathological condition where fibrous connective tissue invades any organ, usually as a consequence of inflammation or other injury.Bronchiolitis Obliterans, aspleniaAspleniaAsplenia is the absence of splenic tissue or function and can stem from several factors ranging from congenital to iatrogenic. There is a distinction between anatomic asplenia, which is due to the surgical removal of the spleen, and functional asplenia, which is due to a condition that leads to splenic atrophy, infarct, congestion, or infiltrative disease. Asplenia, burn injuries, and indwelling catheters/endotracheal intubationEndotracheal IntubationNeonatal Respiratory Distress Syndrome. Management is primarily with piperacillinPiperacillinSemisynthetic, broad-spectrum, ampicillin derived ureidopenicillin antibiotic proposed for pseudomonas infections. It is also used in combination with other antibiotics.Penicillins/tazobactamTazobactamA penicillanic acid and sulfone derivative and potent beta-lactamase inhibitor that enhances the activity of other anti-bacterial agents against beta-lactamase producing bacteria.Cephalosporins.
Gram-negative bacteriagram-negative bacteriaBacteria which lose crystal violet stain but are stained pink when treated by gram’s method.Bacteriology: Most bacteriaBacteriaBacteria are prokaryotic single-celled microorganisms that are metabolically active and divide by binary fission. Some of these organisms play a significant role in the pathogenesis of diseases. Bacteriology can be classified according to a lab procedure called Gram stainingGram stainingBacteriology. BacteriaBacteriaBacteria are prokaryotic single-celled microorganisms that are metabolically active and divide by binary fission. Some of these organisms play a significant role in the pathogenesis of diseases. Bacteriology with cell walls that have a thin layer of peptidoglycanPeptidoglycanPenicillins do not retain the crystal violet stain utilized in Gram stainingGram stainingBacteriology. These bacteriaBacteriaBacteria are prokaryotic single-celled microorganisms that are metabolically active and divide by binary fission. Some of these organisms play a significant role in the pathogenesis of diseases. Bacteriology do, however, retain the safranin counterstain and thus appear as pinkish-red on the stain, making them gram negativeGram negativeBacteria which lose crystal violet stain but are stained pink when treated by gram’s method.Yersinia spp./Yersiniosis. These bacteriaBacteriaBacteria are prokaryotic single-celled microorganisms that are metabolically active and divide by binary fission. Some of these organisms play a significant role in the pathogenesis of diseases. Bacteriology can be further classified according to morphology (diplococci, curved rods, bacilliBacilliShigella, and coccobacilli) and their ability to grow in the presence of oxygen (aerobic versus anaerobic). The bacteriaBacteriaBacteria are prokaryotic single-celled microorganisms that are metabolically active and divide by binary fission. Some of these organisms play a significant role in the pathogenesis of diseases. Bacteriology can be more narrowly identified by growing them on specific media (triple sugar ironIronA metallic element with atomic symbol fe, atomic number 26, and atomic weight 55. 85. It is an essential constituent of hemoglobins; cytochromes; and iron-binding proteins. It plays a role in cellular redox reactions and in the transport of oxygen.Trace Elements (TSITSIShigella) agar) where their enzymesEnzymesEnzymes are complex protein biocatalysts that accelerate chemical reactions without being consumed by them. Due to the body’s constant metabolic needs, the absence of enzymes would make life unsustainable, as reactions would occur too slowly without these molecules. Basics of Enzymes can be identified (ureaseUreaseAn enzyme that catalyzes the conversion of urea and water to carbon dioxide and ammonia.Nocardia/Nocardiosis, oxidaseOxidaseNeisseria) and their ability to ferment lactose can be tested.
* Stains poorly on Gram stainGram stainKlebsiella ** PleomorphicPleomorphicBacteroides rod/coccobacillus
*** Require special transport media
Motile: 1–3 motile flagellaFlagellaA whiplike motility appendage present on the surface cells. Prokaryote flagella are composed of a protein called flagellin. Bacteria can have a single flagellum, a tuft at one pole, or multiple flagella covering the entire surface. In eukaryotes, flagella are threadlike protoplasmic extensions used to propel flagellates and sperm. Flagella have the same basic structure as cilia but are longer in proportion to the cell bearing them and present in much smaller numbers.Helicobacter
CatalaseCatalaseAn oxidoreductase that catalyzes the conversion of hydrogen peroxide to water and oxygen. It is present in many animal cells. A deficiency of this enzyme results in acatalasia.Nocardia/Nocardiosis positive
Non-lactose fermenting
Produces a blue-green pigment: due to pyocyanin and fluorescein production
Photograph depicts the colonial growth pattern displayed by Pseudomonas aeruginosa bacteriaBacteriaBacteria are prokaryotic single-celled microorganisms that are metabolically active and divide by binary fission. Some of these organisms play a significant role in the pathogenesis of diseases. Bacteriology.
ReservoirReservoirAnimate or inanimate sources which normally harbor disease-causing organisms and thus serve as potential sources of disease outbreaks. Reservoirs are distinguished from vectors (disease vectors) and carriers, which are agents of disease transmission rather than continuing sources of potential disease outbreaks. Humans may serve both as disease reservoirs and carriers.Escherichia coli and transmission
ReservoirReservoirAnimate or inanimate sources which normally harbor disease-causing organisms and thus serve as potential sources of disease outbreaks. Reservoirs are distinguished from vectors (disease vectors) and carriers, which are agents of disease transmission rather than continuing sources of potential disease outbreaks. Humans may serve both as disease reservoirs and carriers.Escherichia coli:
Ubiquitous in the environment
Moist reservoirs:
Sinks
Respiratory and dialysisDialysisRenal replacement therapy refers to dialysis and/or kidney transplantation. Dialysis is a procedure by which toxins and excess water are removed from the circulation. Hemodialysis and peritoneal dialysis (PD) are the two types of dialysis, and their primary difference is the location of the filtration process (external to the body in hemodialysis versus inside the body for PD).Peritoneal Dialysis and Hemodialysis equipment
Transmission:
Person-to-person transmission from infected reservoirs
Risk factors
NeutropeniaNeutropeniaNeutrophils are an important component of the immune system and play a significant role in the eradication of infections. Low numbers of circulating neutrophils, referred to as neutropenia, predispose the body to recurrent infections or sepsis, though patients can also be asymptomatic. Neutropenia
Burn injuries
AspleniaAspleniaAsplenia is the absence of splenic tissue or function and can stem from several factors ranging from congenital to iatrogenic. There is a distinction between anatomic asplenia, which is due to the surgical removal of the spleen, and functional asplenia, which is due to a condition that leads to splenic atrophy, infarct, congestion, or infiltrative disease. Asplenia
Table: VirulenceVirulenceThe degree of pathogenicity within a group or species of microorganisms or viruses as indicated by case fatality rates and/or the ability of the organism to invade the tissues of the host. The pathogenic capacity of an organism is determined by its virulence factors.Proteus factors
VirulenceVirulenceThe degree of pathogenicity within a group or species of microorganisms or viruses as indicated by case fatality rates and/or the ability of the organism to invade the tissues of the host. The pathogenic capacity of an organism is determined by its virulence factors.Proteus factor
Effect
Polysaccharide capsulePolysaccharide capsuleAn envelope of loose gel surrounding a bacterial cell which is associated with the virulence of pathogenic bacteria. Some capsules have a well-defined border, whereas others form a slime layer that trails off into the medium. Most capsules consist of relatively simple polysaccharides but there are some bacteria whose capsules are made of polypeptides.Klebsiella
Antiphagocytic
Adherence to tracheal epitheliumEpitheliumThe epithelium is a complex of specialized cellular organizations arranged into sheets and lining cavities and covering the surfaces of the body. The cells exhibit polarity, having an apical and a basal pole. Structures important for the epithelial integrity and function involve the basement membrane, the semipermeable sheet on which the cells rest, and interdigitations, as well as cellular junctions. Surface Epithelium: Histology
AidsAIDSChronic HIV infection and depletion of CD4 cells eventually results in acquired immunodeficiency syndrome (AIDS), which can be diagnosed by the presence of certain opportunistic diseases called AIDS-defining conditions. These conditions include a wide spectrum of bacterial, viral, fungal, and parasitic infections as well as several malignancies and generalized conditions. HIV Infection and AIDS in prolonged colonizationColonizationBacteriology/biofilmBiofilmEncrustations formed from microbes (bacteria, algae, fungi, plankton, or protozoa) embedded in an extracellular polymeric substance matrix that is secreted by the microbes. They occur on body surfaces such as teeth (dental deposits); inanimate objects, and bodies of water. Biofilms are prevented from forming by treating surfaces with dentifrices; disinfectants; anti-infective agents; and anti-fouling agents.Staphylococcus production
PiliPiliFilamentous or elongated proteinaceous structures which extend from the cell surface in gram-negative bacteria that contain certain types of conjugative plasmid. These pili are the organs associated with genetic transfer and have essential roles in conjugation. Normally, only one or a few pili occur on a given donor cell. This preferred use of ‘pili’ refers to the sexual appendage, to be distinguished from bacterial fimbriae, also known as common pili, which are usually concerned with adhesion.Salmonella
Adherence to respiratory epitheliumEpitheliumThe epithelium is a complex of specialized cellular organizations arranged into sheets and lining cavities and covering the surfaces of the body. The cells exhibit polarity, having an apical and a basal pole. Structures important for the epithelial integrity and function involve the basement membrane, the semipermeable sheet on which the cells rest, and interdigitations, as well as cellular junctions. Surface Epithelium: Histology
Phospholipase C
Degrades cell membranes
Exotoxin A
Ribosylates and inactivates EF-2, which causes cell deathCell deathInjurious stimuli trigger the process of cellular adaptation, whereby cells respond to withstand the harmful changes in their environment. Overwhelmed adaptive mechanisms lead to cell injury. Mild stimuli produce reversible injury. If the stimulus is severe or persistent, injury becomes irreversible. Apoptosis is programmed cell death, a mechanism with both physiologic and pathologic effects.Cell Injury and Death
Pyocyanin
Mediates tissue damage through production of reactive oxygen speciesReactive oxygen speciesMolecules or ions formed by the incomplete one-electron reduction of oxygen. These reactive oxygen intermediates include singlet oxygen; superoxides; peroxides; hydroxyl radical; and hypochlorous acid. They contribute to the microbicidal activity of phagocytes, regulation of signal transduction and gene expression, and the oxidative damage to nucleic acids; proteins; and lipids.Nonalcoholic Fatty Liver Disease
Type III secretion systemType III secretion systemMultiprotein transmembrane complexes in gram-negative bacteria involved in either the secretion of effector proteins from the bacterial cytoplasm into host cells, or the secretion and assembly of flagellar components. The major component of the t3sss is called the injectosome or needle complex.Yersinia spp./Yersiniosis
Facilitates direct delivery of toxins to host cell
In vivobiofilmBiofilmEncrustations formed from microbes (bacteria, algae, fungi, plankton, or protozoa) embedded in an extracellular polymeric substance matrix that is secreted by the microbes. They occur on body surfaces such as teeth (dental deposits); inanimate objects, and bodies of water. Biofilms are prevented from forming by treating surfaces with dentifrices; disinfectants; anti-infective agents; and anti-fouling agents.Staphylococcus formation
Allows organism to persist in airways of patientsPatientsIndividuals participating in the health care system for the purpose of receiving therapeutic, diagnostic, or preventive procedures.Clinician–Patient Relationship with cysticCysticFibrocystic ChangefibrosisFibrosisAny pathological condition where fibrous connective tissue invades any organ, usually as a consequence of inflammation or other injury.Bronchiolitis Obliterans
Contributes to multi-drug resistanceResistancePhysiologically, the opposition to flow of air caused by the forces of friction. As a part of pulmonary function testing, it is the ratio of driving pressure to the rate of air flow.Ventilation: Mechanics of Breathing
Mechanisms of pathogenesis of Pseudomonas aeruginosa
Image by Lecturio.
Diseases Caused by P. aeruginosa
Table: Diseases caused by P. aeruginosa
Type of condition
Characteristics
Urinary tractUrinary tractThe urinary tract is located in the abdomen and pelvis and consists of the kidneys, ureters, urinary bladder, and urethra. The structures permit the excretion of urine from the body. Urine flows from the kidneys through the ureters to the urinary bladder and out through the urethra.Urinary Tract: Anatomy infection
Especially in patientsPatientsIndividuals participating in the health care system for the purpose of receiving therapeutic, diagnostic, or preventive procedures.Clinician–Patient Relationship with indwelling catheters
Common cause of nosocomial UTIs
Burn wound infectionsInfectionsInvasion of the host organism by microorganisms or their toxins or by parasites that can cause pathological conditions or diseases.Chronic Granulomatous Disease
Associated with burn injuries, causing:
Vascular damage
Tissue necrosisNecrosisThe death of cells in an organ or tissue due to disease, injury or failure of the blood supply.Ischemic Cell Damage
BacteremiaBacteremiaThe presence of viable bacteria circulating in the blood. Fever, chills, tachycardia, and tachypnea are common acute manifestations of bacteremia. The majority of cases are seen in already hospitalized patients, most of whom have underlying diseases or procedures which render their bloodstreams susceptible to invasion.Glycopeptides
Ear infectionsInfectionsInvasion of the host organism by microorganisms or their toxins or by parasites that can cause pathological conditions or diseases.Chronic Granulomatous Disease
Otitis externaOtitis externaOtitis externa (also known as external otitis or swimmer’s ear) is an infection of the external auditory canal that is most often caused by acute bacterial infection and is frequently associated with hot, humid weather and water exposure. Patients commonly present with ear pain, pruritus, discharge, and hearing loss. Otitis Externa:
Often associated with swimmers (“swimmer’s earSwimmer’s earOtitis exteRNA (also known as external otitis or swimmer’s ear) is an infection of the external auditory canal that is most often caused by acute bacterial infection and is frequently associated with hot, humid weather and water exposure. Patients commonly present with ear pain, pruritus, discharge, and hearing loss.Otitis Externa”)
Malignant external otitisExternal otitisOtitis exteRNA (also known as external otitis or swimmer’s ear) is an infection of the external auditory canal that is most often caused by acute bacterial infection and is frequently associated with hot, humid weather and water exposure. Patients commonly present with ear pain, pruritus, discharge, and hearing loss.Otitis Externa:
BacteremiaBacteremiaThe presence of viable bacteria circulating in the blood. Fever, chills, tachycardia, and tachypnea are common acute manifestations of bacteremia. The majority of cases are seen in already hospitalized patients, most of whom have underlying diseases or procedures which render their bloodstreams susceptible to invasion.Glycopeptides
SepsisSepsisSystemic inflammatory response syndrome with a proven or suspected infectious etiology. When sepsis is associated with organ dysfunction distant from the site of infection, it is called severe sepsis. When sepsis is accompanied by hypotension despite adequate fluid infusion, it is called septic shock.Sepsis and Septic Shock
SkinSkinThe skin, also referred to as the integumentary system, is the largest organ of the body. The skin is primarily composed of the epidermis (outer layer) and dermis (deep layer). The epidermis is primarily composed of keratinocytes that undergo rapid turnover, while the dermis contains dense layers of connective tissue.Skin: Structure and FunctionsinfectionsInfectionsInvasion of the host organism by microorganisms or their toxins or by parasites that can cause pathological conditions or diseases.Chronic Granulomatous Disease
EcthymaEcthymaAn ulcerative pyoderma usually caused by group a beta-hemolytic streptococcal infection at the site of minor trauma.Impetigo gangrenosum:
Rapidly progressive, focal, black, necrotic skinSkinThe skin, also referred to as the integumentary system, is the largest organ of the body. The skin is primarily composed of the epidermis (outer layer) and dermis (deep layer). The epidermis is primarily composed of keratinocytes that undergo rapid turnover, while the dermis contains dense layers of connective tissue.Skin: Structure and Functions lesions
Associated with neutropeniaNeutropeniaNeutrophils are an important component of the immune system and play a significant role in the eradication of infections. Low numbers of circulating neutrophils, referred to as neutropenia, predispose the body to recurrent infections or sepsis, though patients can also be asymptomatic. Neutropenia
Named as such due to the source of infection, which is often from pools/hot tubs
Pulmonary infectionsInfectionsInvasion of the host organism by microorganisms or their toxins or by parasites that can cause pathological conditions or diseases.Chronic Granulomatous Disease
Causes nosocomial pneumoniaPneumoniaPneumonia or pulmonary inflammation is an acute or chronic inflammation of lung tissue. Causes include infection with bacteria, viruses, or fungi. In more rare cases, pneumonia can also be caused through toxic triggers through inhalation of toxic substances, immunological processes, or in the course of radiotherapy.Pneumoniaand ventilator-associated pneumoniaPneumoniaPneumonia or pulmonary inflammation is an acute or chronic inflammation of lung tissue. Causes include infection with bacteria, viruses, or fungi. In more rare cases, pneumonia can also be caused through toxic triggers through inhalation of toxic substances, immunological processes, or in the course of radiotherapy.Pneumonia
Most common cause of chronic pulmonary infection in patientsPatientsIndividuals participating in the health care system for the purpose of receiving therapeutic, diagnostic, or preventive procedures.Clinician–Patient Relationship with cysticCysticFibrocystic ChangefibrosisFibrosisAny pathological condition where fibrous connective tissue invades any organ, usually as a consequence of inflammation or other injury.Bronchiolitis Obliterans
Eye infectionsInfectionsInvasion of the host organism by microorganisms or their toxins or by parasites that can cause pathological conditions or diseases.Chronic Granulomatous Disease
Occurs in contact lensLensA transparent, biconvex structure of the eye, enclosed in a capsule and situated behind the iris and in front of the vitreous humor (vitreous body). It is slightly overlapped at its margin by the ciliary processes. Adaptation by the ciliary body is crucial for ocular accommodation.Eye: Anatomy wearers or minor eye trauma:
Corneal ulcersCorneal UlcersLoss of epithelial tissue from the surface of the cornea due to progressive erosion and necrosis of the tissue; usually caused by bacterial, fungal, or viral infection.Corneal Abrasions, Erosion, and Ulcers
Disseminated infectionsInfectionsInvasion of the host organism by microorganisms or their toxins or by parasites that can cause pathological conditions or diseases.Chronic Granulomatous Disease
Occurs in immunocompromisedimmunocompromisedA human or animal whose immunologic mechanism is deficient because of an immunodeficiency disorder or other disease or as the result of the administration of immunosuppressive drugs or radiation.Gastroenteritis hosts:
Transplant patientsPatientsIndividuals participating in the health care system for the purpose of receiving therapeutic, diagnostic, or preventive procedures.Clinician–Patient Relationship
Neutropenic patientsPatientsIndividuals participating in the health care system for the purpose of receiving therapeutic, diagnostic, or preventive procedures.Clinician–Patient Relationship
OsteomyelitisOsteomyelitisOsteomyelitis is an infection of the bone that results from the spread of microorganisms from the blood (hematogenous), nearby infected tissue, or open wounds (non-hematogenous). Infections are most commonly caused by Staphylococcus aureus.Osteomyelitis
Often in patientsPatientsIndividuals participating in the health care system for the purpose of receiving therapeutic, diagnostic, or preventive procedures.Clinician–Patient Relationship with IV drug use or diabetesDiabetesDiabetes mellitus (DM) is a metabolic disease characterized by hyperglycemia and dysfunction of the regulation of glucose metabolism by insulin. Type 1 DM is diagnosed mostly in children and young adults as the result of autoimmune destruction of β cells in the pancreas and the resulting lack of insulin. Type 2 DM has a significant association with obesity and is characterized by insulin resistance.Diabetes Mellitus
Associated with puncture wounds
A lateral neckNeckThe part of a human or animal body connecting the head to the rest of the body.Peritonsillar Abscess radiograph showing epiglottitisEpiglottitisEpiglottitis (or “supraglottitis”) is an inflammation of the epiglottis and adjacent supraglottic structures. The majority of cases are caused by bacterial infection. Symptoms are rapid in onset and severe.Epiglottitis and complete obstruction of the airways in a 5-year-old girl. The condition is commonly caused by the HaemophilusHaemophilusHaemophilus is a genus of Gram-negative coccobacilli, all of whose strains require at least 1 of 2 factors for growth (factor V [NAD] and factor X [heme]); therefore, it is most often isolated on chocolate agar, which can supply both factors. The pathogenic species are H. influenzae and H. ducreyi.Haemophilus influenzae bacteriaBacteriaBacteria are prokaryotic single-celled microorganisms that are metabolically active and divide by binary fission. Some of these organisms play a significant role in the pathogenesis of diseases. Bacteriology.
Image: “Acute epiglottitisEpiglottitisEpiglottitis (or “supraglottitis”) is an inflammation of the epiglottis and adjacent supraglottic structures. The majority of cases are caused by bacterial infection. Symptoms are rapid in onset and severe.Epiglottitis as the initial presentationPresentationThe position or orientation of the fetus at near term or during obstetric labor, determined by its relation to the spine of the mother and the birth canal. The normal position is a vertical, cephalic presentation with the fetal vertex flexed on the neck.Normal and Abnormal Labor of pediatric Systemic Lupus ErythematosusSystemic lupus erythematosusSystemic lupus erythematosus (SLE) is a chronic autoimmune, inflammatory condition that causes immune-complex deposition in organs, resulting in systemic manifestations. Women, particularly those of African American descent, are more commonly affected.Systemic Lupus Erythematosus” by Charuvanij S et alALAmyloidosis. License: CC BY 2.0
Image showing EcthymaEcthymaAn ulcerative pyoderma usually caused by group a beta-hemolytic streptococcal infection at the site of minor trauma.Impetigo Gangrenosum due to pseudomonas bacteriaBacteriaBacteria are prokaryotic single-celled microorganisms that are metabolically active and divide by binary fission. Some of these organisms play a significant role in the pathogenesis of diseases. Bacteriology in an immunocompromisedimmunocompromisedA human or animal whose immunologic mechanism is deficient because of an immunodeficiency disorder or other disease or as the result of the administration of immunosuppressive drugs or radiation.Gastroenteritis child
Image: “A single black ulcer in a child with acute lymphocytic leukemia” by Michelangelo Vestita et alALAmyloidosis. License: CC BY 4.0
Antimicrobials
Treatment
P. aeruginosa has varying resistanceResistancePhysiologically, the opposition to flow of air caused by the forces of friction. As a part of pulmonary function testing, it is the ratio of driving pressure to the rate of air flow.Ventilation: Mechanics of Breathing to antibiotics:
Multi-drug resistant: resistant to at least 1 agent in > 3 antibiotic categories
Extensively drug resistant: resistant to at least 1 agent in all but 2 antibiotic categories
Pan-drug resistant: resistant to all antibiotic categories
Antibiotic choice is tailored to local resistanceResistancePhysiologically, the opposition to flow of air caused by the forces of friction. As a part of pulmonary function testing, it is the ratio of driving pressure to the rate of air flow.Ventilation: Mechanics of Breathing patterns (combination antibiotic therapy):
1st line:
Combination penicillinPenicillinRheumatic Fever/beta-lactamaseBeta-LactamasePenicillins inhibitors (piperacillinPiperacillinSemisynthetic, broad-spectrum, ampicillin derived ureidopenicillin antibiotic proposed for pseudomonas infections. It is also used in combination with other antibiotics.Penicillins/tazobactamTazobactamA penicillanic acid and sulfone derivative and potent beta-lactamase inhibitor that enhances the activity of other anti-bacterial agents against beta-lactamase producing bacteria.Cephalosporins)
CephalosporinsCephalosporinsCephalosporins are a group of bactericidal beta-lactam antibiotics (similar to penicillins) that exert their effects by preventing bacteria from producing their cell walls, ultimately leading to cell death. Cephalosporins are categorized by generation and all drug names begin with “cef-” or “ceph-.” Cephalosporins (ceftazidimeCeftazidimeSemisynthetic, broad-spectrum antibacterial derived from cephaloridine and used especially for pseudomonas and other gram-negative infections in debilitated patients.Cephalosporins)
Monobactam (aztreonamAztreonamThe carbapenems and aztreonam are both members of the bactericidal beta-lactam family of antibiotics (similar to penicillins). They work by preventing bacteria from producing their cell wall, ultimately leading to bacterial cell death. Carbapenems and Aztreonam)
FluoroquinolonesFluoroquinolonesFluoroquinolones are a group of broad-spectrum, bactericidal antibiotics inhibiting bacterial DNA replication. Fluoroquinolones cover gram-negative, anaerobic, and atypical organisms, as well as some gram-positive and multidrug-resistant (MDR) organisms. Fluoroquinolones (ciprofloxacinCiprofloxacinA broad-spectrum antimicrobial carboxyfluoroquinoline.Fluoroquinolones) (only oral)
CarbapenemsCarbapenemsA group of beta-lactam antibiotics in which the sulfur atom in the thiazolidine ring of the penicillin molecule is replaced by a carbon atom. Thienamycins are a subgroup of carbapenems which have a sulfur atom as the first constituent of the side chain.Carbapenems and Aztreonam (meropenemMeropenemA thienamycin derivative antibacterial agent that is more stable to renal dehydropeptidase I than imipenem, but does not need to be given with an enzyme inhibitor such as cilastatin. It is used in the treatment of bacterial infections, including infections in immunocompromised patients.Carbapenems and Aztreonam)
Multi-drug-resistant strains are treated with newly developed antibiotics:
Beta-lactam-beta-lactamase inhibitor combinations (ceftolozaneCeftolozaneCephalosporins/tazobactamTazobactamA penicillanic acid and sulfone derivative and potent beta-lactamase inhibitor that enhances the activity of other anti-bacterial agents against beta-lactamase producing bacteria.Cephalosporins)
CephalosporinsCephalosporinsCephalosporins are a group of bactericidal beta-lactam antibiotics (similar to penicillins) that exert their effects by preventing bacteria from producing their cell walls, ultimately leading to cell death. Cephalosporins are categorized by generation and all drug names begin with “cef-” or “ceph-.” Cephalosporins (cefiderocolCefiderocolMultidrug-resistant Organisms and Nosocomial Infections)
Adjunct antibiotics: aminoglycosidesAminoglycosidesAminoglycosides are a class of antibiotics including gentamicin, tobramycin, amikacin, neomycin, plazomicin, and streptomycin. The class binds the 30S ribosomal subunit to inhibit bacterial protein synthesis. Unlike other medications with a similar mechanism of action, aminoglycosides are bactericidal. Aminoglycosides (tobramycin, gentamicinGentamicinAminoglycosides, amikacin)
To help remember the many clinically relevant facts about Pseudomonas, use the mnemonic “PSEUDOMONAS”:
Pneumonia, pyocyanin
Sepsis
Ecthyma gangrenosum
UTIs
Diabetes, drug use
Osteomyelitis
Mucoid, polysaccharide capsulePolysaccharide capsuleAn envelope of loose gel surrounding a bacterial cell which is associated with the virulence of pathogenic bacteria. Some capsules have a well-defined border, whereas others form a slime layer that trails off into the medium. Most capsules consist of relatively simple polysaccharides but there are some bacteria whose capsules are made of polypeptides.Klebsiella
Otitis externa (“swimmer’s earSwimmer’s earOtitis exteRNA (also known as external otitis or swimmer’s ear) is an infection of the external auditory canal that is most often caused by acute bacterial infection and is frequently associated with hot, humid weather and water exposure. Patients commonly present with ear pain, pruritus, discharge, and hearing loss.Otitis Externa”)
Nosocomial infectionsInfectionsInvasion of the host organism by microorganisms or their toxins or by parasites that can cause pathological conditions or diseases.Chronic Granulomatous Disease (catheters, endotracheal tubes)
Exotoxin A
Skin infectionsInfectionsInvasion of the host organism by microorganisms or their toxins or by parasites that can cause pathological conditions or diseases.Chronic Granulomatous Disease (“hot tub” folliculitis and burnsBurnsA burn is a type of injury to the skin and deeper tissues caused by exposure to heat, electricity, chemicals, friction, or radiation. Burns are classified according to their depth as superficial (1st-degree), partial-thickness (2nd-degree), full-thickness (3rd-degree), and 4th-degree burns. Burns)
References
Riedel, S., & Hobden, J.A. (2019). In Riedel S, Morse SA, et al (Eds.), Jawetz, Melnick, & Adelberg’s Medical Microbiology (28th ed.)
Hohmann, E.L., & Portnoy, D.A. (2018). In Jameson JL, et al (Eds.), Harrison’s Principles of Internal Medicine (20th ed. Vol 2, pp. 2676–2683).
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