Lecture 3 Bacterial Pathogens Part 2 Flashcards
Regarding neisseria, what are the types, habitat, and infections?
Types: N. gonorrhoeae, N. meningitidis
Habitat: For gonorrhoeae: always pathogen in humans (N. g), found on mucosal surfaces (GU tract), sexual transmission (N. g)
For meningitidis: throat, nasopharynx, 10% of population asymptomatic carriers, respiratory droplet transmission
Infections: gonorrhea (urethra, rectum, cervix, throat, eyes, joints, disseminated)
meningitis, meningococcemia
they are gram - cocci
What are basic ID factors for Neisseria gonorrhoeae?
grey glistening colonies on agar
oxidase +
gram - diplococci
males: usually symptomatic, painful urination and pus
Females: often asymptomatic, can infect cervix and other parts of uterus, can cause pelvic inflammatory disease and sterility
What are basic ID factors for Neisseria meningitidis?
gram - diplococci, oxidase +
causes severe disease ⇒ meningitis and meningococcemia - fever, H/A, stiff neck, photophobia, vomiting, muscle aches, progresses rapidly to shock and potentially death (even as fast as 6 hours), those living in close contact are at risk, prompt tx and prophylaxis can save lives
Regarding moraxella, what are types, habitat, and infections, and ID?
Types: M. catarrhalis
Habitat: URT of humans
Infections: ear infections, sinusitis, exacerbations of COPD
gram - cocci, similar appearing to Neisseria but are larger (diplococci), oxidase +
Regarding haemophilus, what are the types, habitat, and infections, and ID?
Types: H. influenzae
Habitat: URT of humans, transmitted via respiratory droplets
Infections: ear, sinusitis, conjunctivitis, pneumonia, epiglottitis, sepsis, meningitis
gram - coccobacillus, nutritionally fastidious, resemble elongated cocci
Regarding bordetella, what are the types, habitat, and infections, and ID?
Types: B. pertussis, B. parapertussis,, Habitat: URT of humans, transmitted via respiratory droplets (extremely contagious)
Infections; whooping cough
gram - coccobacillus, fastidious, requires enriched media, nucleic acid detection is usual method
Three Phases: Catarrhal phase - sneezing, mild cough ⇒ Paroxysmal phase - coughing spasms, whooping, vomiting ⇒ Convalescent phase - coughing continues for weeks
Regarding legionella, what are the types, habitat, and infections, and ID?
Types: L. pneumophila
Habitat: water (natural bodies as well, plumbing, water heaters, cooling towers, spas), soil, transmitted via water aerosols, not human-human
Infections: Legionnaire’s disease, Pontiac fever
gram - bacillus, nutritionally fastidious, opal like colonies on specialized media, faintly stained gram -
What infections are associated with L. pneumophila?
Legionnaire’s: severe pneumonia often requiring ICU, can result in death if care not received
Pontiac Fever: self-limited febrile illness, few specific sx, resolves without antibiotics in few day
Regarding pseudomonas, what are types, habitat, infections?
Types: P. aeruginosa
Habitat: ubiquitous in environment, can become normal flora after perturbations in someone’s natural microbiota
Infections: pneumonia, bone and joint, skin and soft tissue, ear and eye, UTIs
What are basic ID factors for P. aeruginosa?
gram - bacillus
can appear metallic, rough, pigmented or mucoid
colonies often have grape or corn tortilla smell
oxidase +
glucose non-fermenter
Regarding stenotrophomonas and acinetobacter, what are types, habitat, infections, and ID?
Types: S. maltophilia
A. baumanni
Habitat: soil, water, infections usually hospital acquired or associated with natural disasters and wars
Infections: pneumonia, sepsis, wound and soft tissue, UTIs
gram - bacilli
are glucose non-fermenters
Regarding enterobacteriaceae, what are types, habitat, infections?
Types: Escherichia coli, Klebsiella pneumoniae, Salmonella typhi, Yersinia pestis, Proteus species, Enterobacter species, Shigella species
Habitat: soil, water, various animals, some the GI tract
Infections: wound and soft tissue, UTIs, pneumonia, intraabdominal and abscesses, gastroenteritis, sepsis
are all gram -
What are basic ID factors of E. coli, and some infections associated?
large shiny beta-hemolytic colonies,, lactose fermenting
gram - bacilli
Infections: traveler’s diarrhea, “hamburger disease” - bloody diarrhea, severe ab cramping ⇒ toxin-mediated
also UTIs and subsequent sepsis
How does Salmonella typhi cause typhoid fever?
IC pathogen hijacks macrophages and carried from intestine into lymphatics, liver, spleen, bone marrow ⇒ destroy macrophage and break out into bloodstream to invade body ⇒ consists of fever, H/A, ab pain, diarrhea or constipation, rash
can cause septic shock, intestinal perforation, and death
Bacteroides species (types, infections)
is a gram - anaerobic bacilli species,, make up 20-30% of bacterial gut flora
Types: B. fragilis most important,, can contribute to polymicrobial infections
Infections: escape from gut: abscess formation (ab, brain, liver, pelvis, lungs), bacteremia
cause infection via capsule, EC enzymes, LPS, pili, enterotoxin
Porphyromonas species (types, infections)
is a gram - anaerobic bacilli species,, Types: P. gingivalis well known
all species produce pigment
Infections: dental disease, periodontitis, necrotizing ulcerative gingivitis, infected root canals, peri-implant lesions, acute apical abscesses, bacteremia
cause infection via capsule EC enzymes, LPS, pili
Prevotella species (infections)
is a gram - anaerobic bacilli species,, found predominantly in oral cavity, fluoresce brick-red under UV light
Infections: all types of dental infections, often isolated from human bite wound infections, abscesses, bacteremia
Fusobacterium species (types, infections)
is a gram - anaerobic bacilli species
pleomorphic coccoid to long curled forms,, Types: F. necrophorum most significant
Infections: dental, tonsillitis, abscesses, bacteremia, Lemierre’s syndrome
Actinomyces species (infections)
are aerotolerant gram + bacilli
found in oral, GI and GU sites
often grow as filamentous, branching rods, have a ‘molar tooth’ colony morphology
Infections: actinomycosis - slow chronic infection, abscesses, crosses tissue boundaries, sinus tract formation
Cutibacterium species (types, infections)
are aerotolerant gram + bacilli
Types: C. acnes most significant
found naturally on skin, good at forming biofilms
Infections: prosthetic joints
Regarding clostridium, what are the different types, and basic ID?
they are gram + rods, spore formers, > 200 species, toxin-producing pathogens
Types: C. tetani, C. botulinum, C. difficile, C. perfringens
Clostridium tetani (transmission, toxin(s), disease, result of disease (sx))
gram + rod
Transmission: soil, penetrating injuries
Toxin: this toxin
Disease: this
Sx: severe muscle spasms following penetrating injury, trismus (lockjaw), stiff neck, arched back, periods of apnea, rigid abdomen
Clostridium botulinum (transmission, toxin(s), disease, result of disease (sx))
gram + rod
Transmission: soil/dust, home-canned goods, raw honey
Toxin: this toxin
Disease: this
Sx: bilateral cranial nerve dysfunction: blurred or double vision, ptosis (eyelid drooping), dysphagia, dysarthria, facial weakness
symmetric descending weakness/paralysis
Clostridium difficile (transmission, toxin(s), disease, result of disease (sx))
gram + rod
Transmission: antibiotic use, this carriage in other pt
Toxin: Toxin A (enterotoxin), Toxin B (cytotoxin),, Disease: diarrhea +/- complications
Sx: antibiotic associated diarrhea, watery, severe colitis, pseudomembranous colitis, toxic megacolon
Clostridium perfringens (transmission, toxin(s), disease, result of disease (sx))
gram + rod
Transmission: foodborne, normal GI flora
Toxin: this enterotoxin, alpha and theta toxins,, Disease: diarrhea, gas gangrene
Sx: gas gangrene (clostridial myonecrosis), this related gas gangrene often due to trauma with deep penetrating injuries
