Microbiology & Public Health Module 6 PDF

Negative Stain used to demonstrate the presence of capsules Endospore Stain used to detect the presence of endospore Flagella Stain used to demonstrate the presence of flagella BACTERIOLOGY Gram-Positive Bacteria Staphylococcus aureus -G(+) cocci Folliculitis Infection of the hair follicle causing r...

Negative Stain used to demonstrate the presence of capsules Endospore Stain used to detect the presence of endospore Flagella Stain used to demonstrate the presence of flagella BACTERIOLOGY Gram-Positive Bacteria Staphylococcus aureus -G(+) cocci Folliculitis Infection of the hair follicle causing red, pus-filled swollen follicles Impetigo Small, flattened, red patches on the face and limbs which develop into pus filled vesicles that eventually crust over. AKA pyoderma Toxic Shock Syndrome Occurs in young women Caused by TSST 1 S/Sx: Fever Hypotension Erythoderma wit desquamation Profuse diarrhea Multi-organ involvement Staphylococcal Scalded Skin Syndrome S/Sx: Perioral erythema with sunburn like rash rapidly turning bright red then spreading to bullae which later on desquamates Staphylococcal Food Poisoning Caused by ingestion of enterotoxin Second most common cause of acute food poisoning S/Sx: Acute salivation Nausea Vomiting Abdominal cramps Watery diarrhea Septicemia Associated with age extremes, CVD, decompensated diabetes, and heroin addicts May complicate to endocarditis 5 | Prepared by: Santi Raphael B. Lledo, RPh Other infections caused by S. aureus Sty, boil, cellulitis, impetigo, osteomyelitis Streptococcus viridans “green” Normal flora of the oral cavity Streptocccus mutans Causes bad breath, dental carries CHO to lactic acid Complication: brain abscess Streptococcus pyogenes Most virulent, important human pathogen CM: o Scarlet Fever ▪ Aka. Scarletina, erysipelas ▪ ID: Dick’s test o Impetigo ▪ Aka pyoderma ▪ s/s: yellow crusted lesions (face) o Sepsis o Infectious endocarditis o Tonsilitis, Strep throat (3-5x/yr = complications) o Pharyngitis Complications (1-4 weeks after infection) o Acute Rheumatic Fever ▪ Heart murmurs ▪ Aschoff’s nodule formation in the heart valves o Acute Glomerulonephritis o Rx: Penicillin V Streptococcus agalactiae Normal flora of female genitalia CM: neonatal sepsis/meningitis (from mother) Enterococcus (faecalis, faecium, durans) CM: o liver, intestinal abscess o UTI Streptococcus bovis Normal flora of the colon Common org. isolated among patients with colon cancer Spore-forming Gram-Positive Rods Bacillus anthracis Only bacteria with an amino acid capsule Causes anthrax Cutaneous: exotoxin causes localized tissue necrosis “black eschar lesions” Respiratory: “Woolsorter’s” disease GI: rare but fatal Normal flora of sheep, goat, cattle Encapsulated (with D-glutamic acid in capsule) ID test: MacFaydean reaction test Medusa head colony appearance Bacillus cereus Non-encapsulated, motile Produces exotoxin Causes food poisoning: emetic/diarrheal Bacillus subtilis CM: UTI Source of Bacitracin (wound of Margaret Tracey) Clostridium botulinum Normal flora of animals Inh. Release of Ach in skeletal muscles Acquired by humans through: o Deep wound infection o Consumption of vacuum packed or canned foods o Consumption of honey by infants S/S: o Flaccid Paralysis ▪ Lack of muscle tone, “Flappy baby syndrome” ▪ Starts with facial muscles o Diaphragmatic paralysis – respiratory arrest o Diplopia, slurred speech, swallowing difficulty Used in dermatology – Botox Rx: Trivalent antitoxin Clostridium tetani Normal flora of horses, dogs CM: Tetanus S/S: o Spastic paralysis o Ricus sardonicus – sardonic smile/”devil’s grin” o Opisthotonus – hyperarching of back muscles – spine may break o Lock jaw 6 | Prepared by: Santi Raphael B. Lledo, RPh Clostridium perfringens CM: Gas Gangrene S/S: Myonecrosis – liberation of foul smelling gas ID Test: Nagler’s Test Tx Options: o Amputation o Maggots – eat necrotic tissue o Hyperbaric chambers – allows O2 to penetrate for blood flow Clostridium difficile Normal flora of colon CM: Pseodomembranous colitis o S/S: bloody diarrhea, abdominal cramps o Associated with use of broad spectrum antibiotics Non-spore forming Gram positive Rods Corynebacterium diphtheriae V-shaped or palisades “Chinese lettering” Pleomorphic; aerobic/facultative anaerobic Non-motile, non-encapsulated Screening test: Schick Lab Dx: Loeffler’s slant Listeria monocytogenes Has tumbling end-over-end motility at 22C but not at 37C Facultative anaerobe Catalase ( ) Produces hemolysin Only G(+) with endotoxin Propionibacterium acnes More common in males due to inc. testosterone and sebum CM: Acne S/S: comedone (black, whiteheads) Gram Negative Bacteria Escherichia coli Normally found in GI Become pathogenic only when they reach tissues outside of their normal intestinal sites EPEC: infant and children’s diarrhea ETEC: traveler’s diarrhea (Montezuma’s revenge) EIEC: similar to shigellosis EHEC: verotoxin; bloody diarrhea UTI Sepsis Meningitis Klebsiella pneumoniae 2nd most common cause of G(-) sepsis Pneumonia Proteus mirabilis Very motile, alkaline urine Common cause of UTI infections and nosocomial Shigella dysenteriae Non-motile; non-lactose fermenter Highly adapted to humans Acid resistant Shiga toxin: inactivates 60s ribosomes Salmonella sp Mostly motile; non-lactose fermenter Most produce H2S Form acid in glucose and mannose Lives in GI of animals 1. Typhoid fever – S. typhi DOC: Chloramphenicol, Ciprofloxacin, Ceftriaxone 2. Sepsis – S. choleraesius 3. Diarrhea/Gastroenteritis – S. enetritidis Vibrio cholerae Exotoxin: cholera toxin Watery diarrhea: “rice watery” stools Not an invasive infection Helicobacter pylori Spiral shaped, highly motile, microaerophilic Produce large amounts of urease Adherence factors, motility, mucinase Gastritis, gastric/duodenal ulcers Haemophilus influenzae Small uniform coccobacillus Aerobic or facultative anaerobe Encapsulated 6 distinct antigenic types Growth factors (X,Y) Causes meningitis, epiglottitis, septic arthritis, sepsis Lab diagnosis: Chocolate agar Haemophilus aegyptius Aka Koch-Week’s bacillus, H.infuenzae biotype III CM: Conjunctivitis Haemophilus ducreyi CM: soft chancre known as chancroid (hard chancre – CM of syphilis) S/S: 7 | Prepared by: Santi Raphael B. Lledo, RPh o o Brucella ulcerative lesions in genitalia Lymphadenitis in the groin area B. abortus (cow) B. suis (swine) B. cannis (dog) B. miletensis (goat) CM: Brucellosis aka Malta fever, undulant fever, Bang’s dse Yersinia pestis CM: Bubonic plague aka black death, black plague S/S: buboes (wound) Rodents – rat flea (vector) – humans Francisella tularensis CM: Tularemia aka rabbit fever, deer fly fever Bordetella pertussis Fastidious coccobacilli (+) capsule in virulent strains Strict aerobe Legionella pneumophila Facultative intracellular Aerobic, fastidious Natural habitat is water Causes Legionnaire’s disease and Pontiac fever Neisseria meningitides Meningococcus Glucose and maltose fermenter Piliated Meningitis, meningococcemia Neisseria gonnorheae Gonorrhea, STD PID Gonococcal ophthalmia neonatorum Pseudomonas aeruginosa Motile, obligate aerobic rods Occurs as single bacterium, in pairs in short chains (+) ferment CHO UTI, pneumonia Pigments produced: Pyocyanin Pyoverdin Pyorubin Pyomelanin Chlamydia and Rickettsiae Small, obligate, intracellular Energy parasites Contain DNA and RNA Can synthesize own CHONS Chlamydia Elementary Bodies (EB): infective form Reticulate Bodies (RB): non-infective form Causes conjunctivitis, cervicitis, pneumonia C. trachomatis, C. pneumoniae, C. psittaci Rickettsia Pleomorphic coccobacilli Peptidoglycan-ctg muraminic acid and diaminopimelic acid Growth enhanced by sulfonamides Vector: transmitted via ticks, mites, louse, fleas ID test: Weil-Felix Test s/s: diffused rashes from arthropod bite Rx: TCN, Chloramphenicol, increased resistance to sulfonamides Rickettsia rickettsii Vector: wood tick or dog tick Rocky Mountain Spotted Fever Fever, conjunctival redness, severe headache, rash 2. Acquired/STD o 1st Stage: hard chancre o 2nd Stage: condylema – macupapular rash with cigar butt like burn o Latent: Several years o 3rd Stage: gummas characterized by CNS problems o ID test: venereal dse research lab test (VDRL), Rapid plasma regain o Rx: Pen G (DOC) – administer at gluteus maximuss Borrelia recurrentis Highly flexible Can be cultured in fluid media (blood serum and tissue) Causes Relapsing fever Borrelia burgdorferi CM: Lyme’s disease Vector: Ixodes tick S/s: erythema chronicum migrans Orientia tsutsugamushi CM: Scrub Typhus (vector = mite) Leptospira interrogans Tightly coiled, thin, flexible Causes Leptospirosis CM: Leptospirosis / Weil’s Dse o Commonly from rodents but may be from dogs, bats, squirrels o Acquired by humans from contaminated water S/s: nephritis, meningitis, conjunctivitis, splenomegaly, jaundice Rx: Doxycycline Rickettsia akari CM: Rickettsial Pox (vector = mite) Acid Fast Bacteria Rickettsia prowazekii CM: Brill-Zinser’s Dse/epidemic typhus (vector = louse) Rickettsia australis CM: Queensland Tick Fever (vector = tick) Spirochetes Spiral, motile Have axial filaments Treponema, Borrelia, Leptospira Treponema pallidum Microaerophilic Darkfield microscopy, immunofluorescence, silver stains Causes syphilis CM: Syphilis 1. Congenital (newborn, during 4th month) o s/s: keratoconjunctivitis, perforated palate, saddle nose, patchy mucus membrane, Hutchinson’s teeth o ID test: Flruoresent Treponema test 8 | Prepared by: Santi Raphael B. Lledo, RPh Rod shaped, aerobic Do not form spores Resist decolorization by acid or alcohol Mycobacterium tuberculosis Intracellular organism Slow growing (12-20hr) Weakly G(+) cell wall Resist drying Sensitive to UV, phenol, hypochlorite, heat Virulence factor: cord factor, intracellular survival Growth: Lowenstein-Jensten medium Aka Koch’s bacillus CM: Pulmonary Tuberculosis (PTB) Extrapulmonary tuberculosis (EPTB) Tb of the skin, bones, kidney, and other organs s/s: afternoon fatigue, pm fever, loss of appetite and weight (rapid), cough, hemoptysis (bloody sputum)