Bacterial Characteristics & Diseases PDF

Genus Species Characteristics & Tests Diseases Key Points N. gonorrhoeae Gram-negative diplococci, Gonorrhea (STI) Not normal flora (pathogen...

Genus Species Characteristics & Tests Diseases Key Points N. gonorrhoeae Gram-negative diplococci, Gonorrhea (STI) Not normal flora (pathogen oxidase-positive, sexual and nonsexual) catalase positive, Primarily infects urogenital tract. Glucose positive, fastidious, Can cause pelvic inflammatory capsulated, pili disease (PID) No growth on MAC & BAP Fitz-Hugh-Curtis syndrome. chocolate or Thayer-Martin agar capnophilic- CO2 Growth on CHOC JEMBEC system for transport Confirmatory: Gram-negative diplococci inside PMNs. GERAM NEGATIVE COCCI Neisseria Grow at 37 C (hate cold) Gram-negative diplococci, Meningitis, Carried in nasopharynx. Cause No growth on MAC oxidase-positive Oxidase-positive, meningococcemia Eye infection in children N. meningitidis Maltose positive, Waterhouse- Can cause outbreaks in close Glucose positive, fastidious, Friderichsen communities capsulated syndrome: Adrenal STAT growth on CHOC & BAP & SBA gland failure due to In BSL-2 hemorrhage, a rare Complement system complication of deficiencies, especially in C5-C9 meningococcemia. components (terminal pathway) M. catarrhalis Gram-negative diplococci, Otitis media, sinusitis, Common cause of respiratory oxidase-positive, catalase bronchitis infections, especially in children positive Increasing resistance to beta-lactamase Asaccharolytic antibiotics Moraxella growth on CHOC & BAP. Not on False positive gram stain MAC Hockey pouch colony nitrogen reduction positive DNase positive lipase positive  Genus Species Characteristics & Tests Diseases Key Points H. influenzae Small Gram-negative Meningitis, Most invasive disease caused by coccobacilli, fastidious, pneumonia, otitis type b. Hib vaccine has drastically Grows on CHOC agar (tannish, media, epiglottitis reduced infections moist colonies, mousy odor) NG on BAP without staph streak - Invasive: Virulence factors: capsule (Hib), (satelliting colonies with staph meningitis, IgA protease, LPS, fimbriae streak) epiglottitis (Hib) - Pleomorphic, faint staining Requires X & V factors - Non-invasive: - Encapsulated strains cause Oxidase (+), Catalase (+) otitis media, systemic disease; non- Porphyrin test (-) sinusitis (non- encapsulated cause localized GERAM NEGATIVE COCCOBACILLI Latex agglutination detects Hib typeable strains) disease. First clues include Growth on BAP +staph streak Require growth factor in RBC antigen satellitism, NG on MAC/BAP, and pleomorphic appearance. facultative anaerobes Sub/bio group: H. aegyptius conjunctivitis pathogen Growth on CHOC Haemophilus Gram-negative coccobacilli, (pink eye), NOT On MAC CO2- 35 C Brazilian Purpuric Fever H. ducreyi Gram-negative coccobacilli, Chancroid (STI) Pathogen fastidious Causes genital ulcers Growth around X and XV GUD School of fish arrangement factor Catalase negative Porphyrin negative Oxidase negative Growth around V and XV Rarely pathogenic: Differentiated by Porphyrin test H. parainfluenzae factor endocarditis /ALA(+) Growth on CHOC agar not beta hemolytic Porphyrin test (+) Haemophilus spp. Normal flora (except. H. influenzae & H. ducreyi ). H. aphrophilus requires CO2. Need X factor (hemin) and/or V factor (NAD); "Para" species need only V. Use horse or rabbit blood agar to provide X and V factors. BAP (sheep blood) contains X but requires a V source (S. aureuse and Neisseria) due to NADase enzymes. H. haemolyticus :V&X – beta hemolytic H. parahaemolyticus: V factor- Beta hemolytic  Genus Species Characteristics & Tests Diseases Key Points Haemophilus Gram-negative coccobacillus - Endocarditis - Part of normal flora in the upper aphrophilus - Requires X factor (hemin) for - Respiratory growth- CO2 (INCREASED) infections - Grows on chocolate agar/BAP - Meningitis Aggregatibacter Gram-negative rod eriodontal disease Known for its virulence factors in actinomycetemcomitans, - Facultative anaerobe - Endocarditis periodontal disease HACEK - Catalase-positive, oxidase - Abscesses - Commonly found in dental plaques- positive/negative-no X/V periodontitis Group - Non-motile, CO2, star in center of colony GERAM NEGATIVE coccobacillus Gram- Cardiobacterium Gram-negative coccobacillus Endocarditis Part of normal oral flora negative hominis, Facultative anaerobe, Catalase - Septicemia Associated with subacute endocarditis, coccobacilli, negative, Oxidase-positive, rosette heart valve (needs to be replaced) fastidious, long filament false positive gram stain slow-growing, Eikenella corrodens Gram-negative coccobacillus Human bite wounds Known for its "corroding" effect on normal oral Facultative anaerobe - Endocarditis agar- Part of the normal flora of the flora - Catalase-negative, X factor-co2 - Periodontal mouth and upper respiratory tract - Bleach-like odor-gamma hemol. ("clenched fist injuries") Kingella kingae Gram-negative coccobacillus Pediatric Common cause of osteoarticular Non-motile, sugar fermenter no osteoarticular infections in children May be mistaken gas,- Facultative anaerobe infections - Can cause bacteremia and septic with Neisseria (gram - Oxidase-positive Endocarditis arthritis in young children Catalase negative Septic arthritis false positive gram stain stain identify ) P. multocida Gram-negative bacilli, non- Animal bite Soft tissue infection (rare systemic fastidious- - grow on BAP & CHOC - infections (cats, infection). often ovoid, filamentous, or Pasteurella Gamma hemolytic- dogs), zoonotic bacilli-shaped, with bipolar staining Nonmotile,Catalase cellulitis resembling safety pins. The ends Can be easily positive ,Oxidase positive (most retain more stain. musty wet dog mistaken with isolates),Nitrate positive,Indole odor Haemophilus Positive,ornithine,Positive,Urease *** negative,Glucose fermentation ,Weak acid production *** Haemophilus pasteurella NG on MAC or BAP NG on MAC Growth on CHOC – mousy odor Growth on BAP and CHOC – musty odor Small GNCB Small GNB – Bipolar staining  Infections: Respiratory, can become systemic Infections: Wounds, rarely respiratory or systemic Feature Pathogens Opportunistic Pathogens Non-fermenting Bacilli (NFB) Enterobacteriaceae, LF Enterobacteriaceae NLF Gram Stain Gram-negative rods Gram-negative rods Gram-negative rods or coccobacilli Morphology Lactose Positive (pink colonies) Negative (colorless colonies) Negative (colorless colonies) Fermentation on MAC TSI Result A/A (acid slant/acid butt) K/A (alkaline slant/acid butt) K/K (alkaline slant/alkaline butt) Oxidase Test Negative Negative Variable (often positive) Motility Often motile (e.g., E. coli) Variable (e.g., Shigella is non- Variable (e.g., P. aeruginosa is motile, motile) A. baumannii is non-motile) Metabolism Facultative anaerobes Facultative anaerobes Strict aerobes Environmental Normal flora of the GI tract; can Normal flora or transient Ubiquitous in nature (soil, water, Presence colonize environment colonizers in humans and hospital settings) animals Resistance Susceptibility varies; generally More resistant than LF; some High levels of intrinsic and acquired sensitive to many antibiotics strains have MDR mechanisms antimicrobial resistance Examples of Escherichia coli, Klebsiella Salmonella spp., Shigella spp., Pseudomonas aeruginosa, Pathogens pneumoniae Proteus spp. Acinetobacter baumannii, Stenotrophomonas maltophilia  Genus Species Characteristics & Tests Diseases Key Points Gram-negative rods, LF -UTIs -Normal flora of GI Pink colonies on MAC, - Gastroenteritis -produces acid and gas facultative anaerobe, - Neonatal - VI: Fimbriae (Pili), Motile meningitis enterotoxins Metallic green sheen on - Sepsis (ETEC:Enterotoxigenic, EHEC: Escherichia coli EMB agar shiga toxin), hemolysins, Pathogens Enterobacteriaceae, LF H₂S:Negative capsule (some strains) Oxidase:Negative O antigen (LPS), H antigen Indole:Positive (flagellar), K antigen (capsular; some strains) Endogenous Klebsiella k. pneumoniae Gram-negative rods,LF Pneumonia, UTI, Normal flora of human GI on MAC (Pink, mucoid bacteremia tract and oropharynx colonies Often associated with -VI: Thick polysaccharide (capsule)facultative (HAIs) capsule, siderophores anaerobe, nonmotile K antigen (capsular Large, shiny colonies on polysaccharide) BAP -Can produce extended- H₂S: Negative spectrum beta-lactamases Oxidase: Negative (ESBLs) Indole: Negative (K. Known for multidrug resistance pneumoniae); Positive (K. (e.g., ESBL, CRE) oxytoca)  Enterobacter Gram-negative rods, LF UTI, pneumonia, Normal flora of human GI tract spp. Pink colonies on MAC, wound infections facultative anaerobe. VI: Capsule, siderophores, Motile. resistance genes Enterobacter Large, shiny colonies on - O antigen (LPS), K antigen BAP H₂S: Negative -Known for multidrug resistance Oxidase: Negative -Often associated with HAIs Indole: Varies Genus Species Characteristics & Diseases Key Points Tests Salmonella Salmonella spp. Gram-negative Gastroenteritis (most Produces H2S(exc: S. paratyphi A) S. enterica rods, NLF common) MAC: colorless/clear Enterobacteriaceae facultative - Enteric fever (S. Typhi, XLD&HE: black centers colonies PATHOGENE. (Non-Lactose anaerobe, motile S. Paratyphi.Typhoid Fermenters) VI: Fimbriae, enterotoxin, travers fever) intestinal mucosa - Bacteremia - Carrier state Serotype: O (LPS,cell wall), H - animal FOOD: GI tracts ( flagellar), Vi (capsule)Ag of animals (poultry, eggs, Vi antigen unique to S. Typhi milk); humans in carrier Carrier state involves gallbladde state  Shigella Shigella spp. Gram-negative Dysentery - Non-motile rods,NLF on - MAC(Clear Causes bloody diarrhea - Ability to penetrate epithelial cells colonies), Induce local inflammation - O antigen; lacks H antigen facultative - Shigellosis or Bacillary anaerobe, non- Dysentery Produces no gas (except some S. motile - Watery diarrhea with flexneri) RED colonies on leukocytes - No H₂S XLD; - Bloody, mucus-filled GREEN/clear on stools HE. Lack of hygiene biochemical TEST negative Y. enterocolitica Gn rods, Gastroenteritis Motile at 25°C; nonmotile at 37°C NLF,facultative Survives in cold, anaerobe, "safety Appendicitis-like syndrome Resists phagocytosis pin" on Gram - Erythema nodosum Invades intestinal mucosa Yersinia Stain. colonies - Plague (Y. pestis) O antigen vary based on Appendicitis-like symptoms (Y. temperature Animals (swine, cats, enterocolitica) preferences dogs); fleas (Y. pestis) - Buboes and plague forms (Y. pestis) Genus Species Characteristics & Tests Diseases Key Points Pseudomonas P. aeruginosa Slender Gram-negative Nosocomial UTI, Fruity/ grape-like odor, biofilm rods,NLF, Grow on MAC Pneumonia, wound formation, growth at 42°C Non-Fermenting motile, Polar flagella, infections CF VI: Exotoxin A, elastase, oxidase-positive, patients), sepsis alginate, Type III secretion Bacilli BAP(Large, irregular, system metallic sheen, β- often associated with Innately resistant to many hemolytic )pigments HAIs antibiotics (Pyocyanin (blue-green), pyoverdin (yellow), etc. Acinetobacter A. baumannii Gram-negative Nosocomial UTI, Small coccobacilli, potential coccobacilli, Grow on Pneumonia, false Gram-positive stain MAC, NLF (some with bacteremia, wound Can form biofilms, purplish tinge). Smooth, infections - Often resistant, carbapenem- opaque, creamy, smaller resistant strains (CRAB) than Enterobacterales on Often associated emerging BAP. non-motile, HAIs VI: None specific to oxidase negative, No Acinetobacter pigment Stenotrophomonas S. maltophilia Gram-negative rods, Nosocomial UTI, Strong ammonia smell, Grow on MAC, NLF Pneumonia, DNase positive (some with purplish bacteremia, wound tinge), Large, smooth, infections VI: None specific to S. glistening with uneven immunocompromised maltophilia edges on BAP, motile, hosts (endocarditis, Can produce a variety of oxidase-negative, bacteremia) extracellular enzymes Lavender-green to light Often associated with Inherently resistant to many purple pigment HAIs, antibiotics