Pathogenic bacteria worth mentioning 1

2 Enterococcus: E. faecium, E. faecalis –Formerly part of Group D Strep, found in GI tract –Cause of nosocomial, wound infections –Antibiotic resistant. Gram positive cocci. Listeria monocytogenes, Gram + rod Portal of entry is food or drink,Esp. meat, dairy products. Check for recalls. – –Severe infections in: pregnant women/fetuses, newborns, elderly, immunocompromised

Bacillus Bacillus very common Gram + rods –Present in soil, most non-pathogenic –All form endospores when nutrient limited Bacillus cereus: cause of GI distress –Emetic and diarrheal toxins; badly stored rice Bacillus anthracis : cause of anthrax –3 protein toxin that is lethal –Zoonotic: primarily disease of livestock –Acquired by ingestion, inhalation, and cutaneous 3

3 causes of meningitis Streptococcus pneumoniae –Gram + coccus in pairs; capsules –Pneumonia, sinusitis, otitis media, meningitis Neisseria meningitidis –Gram negative coccus; coffee bean shaped in pairs –Skin rash, sudden high fever; dangerous Hemophilus influenzae: gram negative short rod –mostly respiratory infections and meningitis and epiglottitis in very young. Hib vaccine protects All 3 Carried as normal microbiota by many –Capsule is major virulence factor; 4

Corynebacterium diphtheriae: Gram + rod –cause of disease diphtheria –Colonizes the throat, with inflammation, fever –Toxin inhibits protein synthesis, kills cells –Vaccination (DPT); humans are only host. Bordetella pertussis, small Gram negative rod –cause of whooping cough, respiratory infections –Disease stages: incubation, catarrhal, paroxysmal Coughing and inhalation: whoop –DPT vaccine used to control disease 5

Pseudomonas aeruginosa, Gram negative rod –dangerous opportunist with many virulence factors –major problems: burn patients and cystic fibrosis Cause of swimmer’s ear, hot tub infections, etc. –Resistant to most disinfectants and antibiotics Borrelia burgdorferi: spirochete (Gram -) –cause of Lyme disease –Reservoir in rodents, deer; spread by deer tick –Slow developing; fever, usually bulls-eye rash; arthritis and heart or CNS involvement. 6

7 Mycoplasma and Ureaplasma Mycoplasmas have unusual properties –Very small, odd shapes (cocci to filaments) –Have no cell walls, sterols in their membranes M. pneumoniae, –M. pneumo attaches to epithelial cells, kills them –Fever, malaise, sore throat, etc. walking pneumonia Ureaplasma urealyticum –Sexually transmitted, cause of urethritis –Same for M. genitalium

Two infamous STDs Nesseria gonorrhoeae: cause of gonorrhea –Females: often asymptomatic; or urethritis, PID –Males: painful purulent discharge from urethra –infections anywhere sexual contact occurs –Eye infection of newborns, routine antibiotic Rx Treponema pallidum: cause of syphilis –2-3 stage disease begins with chancre –chancre disappears, spirochete spreads, causes systemic disease (rash, fever, etc) –Either goes away, comes back, or tertiary syphilis in which gummas form; serious stage. 8

9 About Chlamydia, gonorrhea infections Pelvic inflammatory disease (PID): infection and inflammation of the upper genital tract in women. Affects the uterus, fallopian tubes, ovaries. Scarring can lead to infertility, tubal (ectopic) pregnancy, chronic pelvic pain, abscesses, and other serious problems. PID is the most common preventable cause of infertility in the United States.