Medically important bacteria

Medically Important Gram + 

Genus–species Shape Metabolism Diagnosis Symptoms Virulence factors location

transmission

 Therapy
Staphylococci cocci

clusters

 facultative anaerobes         beta lactams
–S. aureus     alpha hemolytic

coagulase +

 TTSS  SSSS

food poisoning

 protein A teichoic acids  Exf toxin   penicillins or cephalosporins. vancomycin if methicillin r
–S. epidermidis     gamma hemolytic

coagulase –

        
Streptoccoci cocci

pairs or chains

 facultative anaerobes catalase –        
–S pyogenes (Group A) short to long chains   beta hemolytic pharyngitis scarlet fever toxic shock outer capsule   penecillin
–S agalactiae (Group B) larger than Group A  require complement beta hemolytic (smaller than Group A) newborn meningitis pneumonia outer capsule    
–S pneumoniae lancet shapped pairs or short chains   alpha hemolytic catalase – pneumonia in elderly & children   throat nasopharynx vacine
–viridan S.     alpha dental caries      
Mycobacteria Bacilli (rods) slow growing acid fast

pigmented 

        
–M. tuberculosis aerobic   skin test (PPPD)     airborn 

alveolar  MQ

 streptomycin riphampin
–M. Leprae     skin test (lepromin)     tropics dapsone
–M. Avium           opportunistic (AIDS patients)  
–M. Kansasi     photo inducible pigment pulmonary like TB      
–M. Marinum           fresh or salt water antibiotics
–M. Fortuitum   faster growing       wounds, catheters  
Bacillus Bacilli (rods)       spores

capsules (some)

    
—B. Anthracis   catalase +

hemalysis –

   Cutaneous A

inhalation A

Gastrointest

 EF, PA, LF toxins    
Clostridium Bacilli (rods)       spores normal flora Gi Tract  
–C. Perfringes       gasgangre   normal flora  
–C. Difficile         A & B toxins   cessation of 

antibiotic treat
–C. Botulinum         spores

AB Toxins

 home canning  
–C. Tetani         spores wounds  

Medically Important Gram –

Genus–species Shape Metabolism Diagnosis Symptoms Virulence factors location

transmission

 Therapy
Neisseria cocci; pairs   oxidase +

catalase +

          
–N. gonnorheae cocci; pairs     PID (women) capsule

pili (pillins)

 2nd most common STD    
–N. Meningitides cocci; pairs aerobic or facultative oxidase +

catalase +

   encapsulation

hemolysis

toxins

pili

 nasopharygyl vacines to all serogroups except B  
Haemophilus bacilli         mucus membranes    
–H. Influenza   aerobic or facultative     capsule (PRP)

pili (adhesins)

IgA proteases

LPS

      
Psudomonas                
P. aeruginosa rods aerobic fastidious lactose –

osidase +

   capsule (alginate, some) exotoxin A cystic fibrosis opportunistic wounds catheters swimmers ear    
Bordatella coccobaccili aerobic 

slow growing

            
B. Pertussis   fasitdious     PT

Pertactin

filamentous hemagglutin

LPS

 whooping cough erythromycin  
Rickettsiae baccili aerobic         tetracycline  
rickettsiae Rickettsii triad         inside cytoplasm

rocky Mt fever

ticks

 tetracycline  
Cociella burnetti           inside vacuoles

Q fever

endocarditis

inhalation

    
Erliichia cahfefeenisis           erlichiosis  teracycline  
Chlamydia No peptidoglycan

pleomorphic

 require ATP from host     Elem Bodies

Ret Bodies

      
C. Trachomatic           PID (women)

LGV (males)

most common STD

    
Legionella  pleomorphic   silver stains

BCYE agar serology (256 titer)

   adhesins (MOMP, MIP) Pontiac Fever

Legionnaires D

intracelluar

    
Francisella tularensis cocco bacillus aerobe       Tuleremia (rabbit, tick deer fever)

facultative intracellular

    
Brucella                
B. abortus cocco bacillus aerobic       intracellular (MQ)

undulant fevor

 tetracycline  
Bartonella rods         intracellular (rickettsia like) antibiotics  
B. henselae and baccilary angiomatosis           immunocompromised    
Spirochettes no LPS

thin

   not visible w/ gram stain          
Treponema Pollidum     darkfield microscopy     Syphillus penecillin  
Borrelia Burgdorferi larger than other spirochettes         lyme disease    
Leptospira interrogans   aerobic       contaminated water penecillin/tetracycline  
Enterobacteriaceae   facultative anaerobic oxidase –   somatic O LPS

capsular K

flagellar H

 normal flura

opportunistic and pathogenic

    
E. coli rods facultative anaerobe Lactose + EHEC (Shiga-like)

ETEC (diarrhea)

heat label Toxin (similar to cholera)

 adhesins

siderophores

alpha hemolysins

 in bowel with other coliforms

endogenous infections

GI fluid loss

    
Klebsiella pneumoniae         capsules immunosuppressed    
Salmonella enterica     lactose –     contaminated food

need large dose

    
Salmonella typhi       typhoid fev   invade MQ

small dose needed

    
Shigella       S. dysenteriae (bloody diarrhea like EHEC)   fecal-oral route

homosexuals

infects M cells using actin machinery

    
Yersinia       bubonic plague (Y. pestis)

pneumonic plague

   high dose required food, drink or fomites