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CULTIVATION Vibrio, - TCBS: yellow or green colonies Plesiomonas, and - Alkaline peptone water Chromobacterium (pH8,4) :...

CULTIVATION Vibrio, - TCBS: yellow or green colonies Plesiomonas, and - Alkaline peptone water Chromobacterium (pH8,4) : enrichment EPIDEMIOLOGY broth for Mode of obtaining Species Habitat Transmission growth of Fecal-oral route vibrios from through stool contaminated Niche outside washing, COMMENTS REGARDING human GIT swimming, SPECFIC ORGANISMS Vibrio cholerae between cooking, or epidemics and drinking water; - Vibrios that do not require salt for growth pandemics ingestion of 1. V. cholerae contaminated 2. V. mimicus shellfish or - Key test in separating halophilic species from seafood o V. cholerae o V. mimicus Ingestion of o Aeromonas spp. Vibrio Brackish or salt contaminated o P. shigellosis parahaemolyticus water seafood - 1% NaCl Ingestion of String test Aquatic Aeromonas contaminated environments - Used to separate Vibrio spp.(+) From water / seafood o Aeromonas spp and Freshwater, o P. shigellosis (-) Ingestion of Plesiomonas especially in contaminated - Organisms is emulsified in 0.5% sodium shigelloides warmer deoxycholate which lysed the vibrio cells food climates Exposure of Environmental, Chromobacterium disrupted skin to found in soil violaceum contaminated soil and water or water PATHOGENESIS AND SPECTRUM OF DISEASE - Vibrio cholerae o Toxins: 1. Cholera toxin § responsible key feature § "rice-watery stools" § fluids and mucous flecks § hallmark of cholera toxin activity 2. Somatic O antigen 01 and 0139 § positive markers for strains § capable of epidemic and § pandemic spread of disease Vibriostatic test 3. Zot toxin - Using 0/129 (2,4 diamino-6-7 Types of infection (depending on the species involved) diisopropylpteridine) 1. Gastroenteritis o impregnated siks to separate vibrios 2. Wound infections (Susceptible) from other oxidase 3. Bacteremia positive LABORATORY DIAGNOSIS SERODIAGNOSIS Direct Detection Methods Methods used for epidemiologic purposes: 1. ELISA - For acute and convalescent sera: o Detects specific antigens or antibodies. 1. Agglutination o Enzyme-Linked ImmunoSorbent Assay. 2. Vibriocidal 2. Latex Agglutination Test 3. Antitoxn test o Detects antigens using tiny latex particles. o Positive result: visible clumping. ANTIMICROBAL SUSCEPTIBILITY TESTING AND THERAPY Vibrio - 2 Components the management of patients: - Gram negative, straight or slightly curved rods 1. Rehydration of patient - Darkfield microscopy: 2. Antimicrobial therapy rapid darting or shooting star motility - Direct microscopic examination: PREVENTION not commonly used - No cholera vaccine available in US Pasteurella and Similar organisms Virulence Spectrum of Organism Factors Disease General characteristics 1. Small, gram negative bacilli - Focal soft 2. Nonmotile, oxidase positive tissue 3. Ferment glucose infections: occur after - Endotoxin: animal bites EPIDEMIOLOGY contributes to or scratches Mode of inflammation Organism Habitat - Chronic Transmission P. multocida - Antiphagocytic respiratory capsule: 1. Animal (cat protects against infection 1. Nasopharynx or dog) bites immune attack - Bacteremia: or scratches can lead to and GIT of wild 2. Non-bite metastatic and domestic Pasteurella exposure abscess animals multocida through formation 2. Part of animal and other handling or normal flora Pasteurella close 3. Associated with LABORATORY DIAGNOSIS species contact with infections in - Specimen special consideration are required for animals various human specimen collection, transport, and processing. 3. History of organs - Other than Gram stain, no specific procedures. animal exposure CULTIVATION (MEDIA OF CHOICE) 1. 5% Sheep blood 2. CAP Habitat Mode of Organism (Reservoir) Transmission COLONIAL APPEARANCE OF 5% SHEEP BLOOD - P. mutocida - Nasopharynx 1. Convex, smooth, gray and GIT of 2. Nonhemolytic, rough & mucoid wild/domestic 3. Musty or mushroom smell animals - Animal Pasteurella - Part of bites/scratches PREVENTION animals' multocida, (cats or dogs) - No recommended vaccination or prophylaxis normal flora other - Non-bite because these organism do not generally pose a Pasteurella - Upper exposure to threat to human health spp., and respiratory animals Mannheimia flora in - Rarely: no Haemophilus haemolytica humans with animal frequent General characteristics exposure animal - Requirement for in vitro growth: exposure 1. Hemin (e.g., animal 2. NAD handlers) EPIDEMIOLOGY - Uncertain habitat - 2 Broad categories of H. influenza strains - Rarely found 1. Typeable strains – based on capsular Suttonella in clinical - Uncertain characteristics indologenes specimens § CAPSULE (sugar alcohol - Possibly part phosphate) of human § Type a, b, c, d, e, and f flora 2. Nontypeable strains – do not produce - Uncertain capsule habitat - Dog bite or § Normal inhabitants of URT Bisgaard's - Likely similar close animal taxon 16 to exposure Pasteurella PATHOGENESIS spp. 1. Production of capsule 2. Bacterial attachment to human epithelial cells - Oral and respiratory - Animal contact 3. Type b H.influenza systemic & life threatening (e.g., 4. Other nontypeable strains -localized CDC group flora of EF-4a animals bites/scratches from cats or H. ducreyi - Not part of dogs) - CHANCROID – STD human flora - Most commonly seen among socioeconomically disadvantaged populations that inhabit tropical environments.  PATHOGENESIS AND SPECTRUM OF DISEASE Habitat Mode of Organism (Reservoir) Transmission Organism Virulence Factors Spectrum of - Person-to- Disease and person Infections spread via Haemophilus § Encapsulated § Life-threatening Haemophilus - Normal flora contaminated of the influenzae strains: infections: influenzae respiratory antiphagocytic meningitis, human (including droplets capsule (type b epiglottitis, upper biogroup respiratory - Infections most common) cellulitis with aegyptius) may arise § Cell envelope bacteremia, tract from factors for host septic arthritis, endogenous attachment pneumonia strains - Person-to- person - Not part of spread § Nonencapsulated § Localized normal through strains: pili and infections: otitis human flora sexual other surface media, sinusitis, Haemophilus ducreyi - Only found contact factors involved conjunctivitis in humans - Causes in attachment § Exacerbation of during chancroid (mechanism not chronic infection (sexually fully understood) bronchitis, transmitted pneumonia, and disease) bacteremia in - Spread of a adults patient’s Other Haemophilus § Uncertain § Purulent endogenous Haemophilus spp. - Normal flora influenzae § Similar to H. conjunctivitis strain to sites biogroup influenzae § Brazilian (H. of the outside the aegyptius purpuric fever parainfluenzae, human respiratory H. upper (severe, tract parahaemolyticus, respiratory high mortality in H. - Rarely children aged tract paraphrophilus) involved in 1-4) purulent human meningitis, infections bacteremia, rash, vascular LABORATORY DIAGNOSIS collapse - Haemophilus spp. Haemophilus § Uncertain § Chancroid: o Susceptible to drying and temperature ducreyi § likely capsular genital lesions extremes. factors, pili, and progressing o H. ducreyi, from genital ulcers, special toxins involved in from tender measures are necessary because of epithelial papules to bacterium fastidious nature. attachment and painful ulcers o Cotton swab moistened with phosphate penetration with satellite buffered saline lesions o Swab in selective medium within 10 § Regional minutes of collection lymphadenitis DIRECT DETECTION METHODS Other § Uncertain § Rare infections Haemophilus § low virulence similar to H. Direct Observation: spp. § Opportunistic influenzae but 1. Gram stain pathogens less frequent 2. Centrifuge (200rpm for 10 minutes) § H. aphrophilus: uncommon Antigen Detection cause of 1. H. influenza type b cpsular polysaccharide endocarditis CULTIVATION (MEDIA) 1. CAP APPROACH TO IDENTIFICATION o Provides the factors: - TRADITIONAL a. hemin (X factor) - Hemolysis on horse or rabbit blood b. NAD (V factor) To establish X and V factor 2. Sheep blood 1. MHA and TSA o Produce V factor; 2. Porphyrin test – detects the presence of o phenomenon called satelliting enzymes that convert H. ducreyi 2 special media to grow 1. Mueller Hinton based chocolate agar supplemented by 1% Isovitalex 2. BHI supplemented w/ 10% Campylobacter, Major Virulence Determinants of Bordetella pertussis Arcobacter and Helicobacter Function Factor/Structure - Fimbriae Helicobacter pylori - Filamentous hemagglutinin (FHA) - Named in 1983 as Campylobacter pylori Adhesion - Pertactin - 22 species included in this genus - Tracheal colonization factor - Curved, Microaerophilic, Gram negative rods - Brk A* EPIDEMIOLOGY AND PATHOGENESIS - Pertussis toxin (an A/B toxin - Primary habitat is human gastric mucosa related to cholera toxin) - Mode of transmission: UNKNOWN - Adenylate cyclase toxin (hemolyzes red cells and activates - Possible routes of transmission: cyclic adenosine monophosphate, 1. Oral-oral thereby inactivating several types of 2. Fecal-oral Toxicity host immune cells) 3. Mother to child- intrafamilial spread - Dermonecrotic toxin (exact role unknown) H.pylori - Tracheal cytotoxin (ciliary - Colonizes mucous layer of the anthrum and dysfunction and damage) fundus of the stomach but does not invade the - Endotoxin epithelium. - Type III secretion† - Motility allows H. pylori to escape the acidity of the stomach - Outer membrane (host lysozyme is Overcome inhibited) Virulence determinants: host - Siderophore production (host 1. CagA – protein injected by H. pylori into defenses lactoferrin and transferrin are unable human gastric epithelial cells to limit iron) 2. Adhesin Notes: 3. Mediators of inflammation Brk A: Plays a role in pathogenesis by conferring 4. Cytotoxin serum resistance. †Type III secretion: Specific mechanism Condition 1. Gastritis associated with overcoming host defenses. 2. Peptic ulcer disease FACTORS KNOWN TO AFFECT THE CLINICAL MANIFESTATION OF B. pertussis INFECTION LABORATORY DIAGNOSIS - Tissue biopsy (Stuart's transport medium) 1. Patient age DIRECT DETECTION 2. Previous immunization or infection 1. Warthin-Starry or other silver stain 3. Presence of passive acquired antibody 2. Giemsa 4. Antibiotic treatment 3. Squash preparation of biopsy material with good results: 0.1% basic fuchsin Examples of Selective Media for Primary Isolation of counterstain. B.pertussis and B. parapertussis Presumptive evidence of the presence of H. pylori 1. Bordet Gengou 1. Placing a portion of crushed biopsy on urea 2. Modified Jones Kendrick Charcoal broth 3. Regart Lowe 2. Urea breath test 3. Two enzyme immunoassay H. pylori stool DIRECT DETECTION METHODS reagent tests 1. Direct Fluorescent antibody (DFA) 4. One step immunochromatographic assay o Detection of B. pertussis in smears made from nasopharyngeal material CULTIVATION 2. PCR 1. CAP o Direct detection of B. pertussis and B. 2. Skirrow’s and Modified Thayer Martin parapertussis 3. Combination of selective (Columbia agar) and o Diagnostic sensitivity selective agar (modified CAP) APPROACH TO IDENTIFICATION Bordetella pertussis and 1. Gram stain Bordetella parapertussis 2. 2 minute safranin "O" counterstain or 0.2% aqueous basic fuchsin counterstain EPIDEMIOLOGY 3. DFA reagent-presumptively identify organisms - PERTUSSIS (Whopping cough) 4. Whole cell agglutination reaction - Epidemic disease with cycles of every 2 to 5 years PREVENTION - Highly contagious, acute infection of upper 1. Whole cell vaccines respiratory tract 2. Acellular vaccines  ANAEROBIC BACTERIOLOGY MAJOR GROUPINGS OF ORGANISMS GENERAL CHARACTERISTICS BELONGING TO GENUS MYCOBACTERIUM 1. They will not grow in the presence of oxygen 1. Mycobacterium tuberculosis complex 2. Actinomyces, Bifidobacteium and Clostridium 2. Nontuberculous Mycobacteria spp a. Slow growing Nonphotochromogens PATHOGENESIS AND SPECTRUM OF DISEASE b. Photochromogen Organism Virulence Spectrum of Disease and c. Scotochromogen Factors Infections d. Noncultivatable Produces e. Rapid growing potentially pathogenic several f. Rarely pathogenic or not yet associated Gas gangrene, a life-threatening, with infections exotoxins; α- toxin-mediated destruction of toxin is most muscle and other tissues important and EPIDEMIOLOGY OF ORGANISMS following traumatic introduction of mediates BELONGING TO M. tuberculosis complex the organism. Food poisoning Clostridium destruction of caused by release of the toxin perfringens host cell after ingestion of large quantities Epidemiology of Organisms Belonging to the M. membranes; enterotoxin of organism. Disease is usually tuberculosis Complex That Cause Human Infections self-limiting and benign and is Organism Habitat Primary Route of Distribution inserts and manifested by abdominal Transmission disrupts cramps, diarrhea, and vomiting. M. Patients Person to person by Worldwide membranes of mucosal cells tuberculosis with inhalation of droplet cavitary nuclei: droplet nuclei Tetanus (also commonly known disease containing the as lockjaw). Organism are primary organism (infectious Produces reservoir aerosols, 1 to 5 μm) establishes a wound infection tetanospasmin, are produced when and elaborates the potent toxin a neurotoxic people with Clostridium that mediates generalized muscle exotoxin that pulmonary tetani spasms. If untreated, spasms disrupts nerve tuberculosis cough, continue to be triggered by even impulses to sneeze, speak, or minor stimuli, leading to muscles sing; infectious exhaustion and, eventually, respiratory failure. aerosols may also be produced by The disease botulism results manipulations of from ingestion of preformed toxin lesions or in nonacidic vegetable or processing clinical mushroom foodstuffs. Absorption specimens in the of the toxin leads to nearly laboratory. Droplets complete paralysis of respiratory are so small that air and other essential muscle currents keep them Produces groups. Other forms of botulism airborne for long Clostridium periods; once extremely potent can occur when the organism botulinum inhaled they are neurotoxins elaborates the toxin after it has colonized the gastrointestinal small enough to tract of infants (e.g., infant reach the lung's botulism). Wound botulism is alveoli. more rare than the other forms M. bovis Humans Ingestion of Worldwide and occurs when C. botulinum and wide contaminated milk produces the toxin from an host range from infected cows; infected wound site. of animals, airborne cattle, transmission. Organism requires diminution of nonhuman Produces toxin normal gut flora by the activity of primates, A, which is an various antimicrobial agents to goats, enterotoxin that become established in the gut of cats, is thought to be hospitalized patients. Once buffalo, primarily established, elaboration of badgers, responsible for toxin(s) results in diarrhea (e.g., possums, the Clostridium antibiotic-associated diarrhea) or dogs, pigs, gastrointestinal difficile potentially life-threatening deer, etc. disease caused inflammation of the colon. When by this M. Inhalation of droplet East and the surface of the inflamed bowel Humans organism. Toxin africanum nuclei. West Africa is overlaid with a B, a cytotoxin, "pseudomembrane" composed of has a less clear necrotic debris, white blood cells, role in C. difficile Notes: and fibrin, the disease is referred infections Infection can occasionally occur through the to as pseudomembranous colitis. gastrointestinal tract or skin. Mycobacteria Incidence is significantly decreased in developed countries since introducing universal 2 MAJOR GROUPS pasteurization of milk and milk products, as well 1. Mycobacterium complex as effective control programs for cattle. 2. Nontuberculous mycobacteria (NTMs) Can be transmitted human to human, animal to human, and human to animal. GENERAL CHARACTERISTICS Infections in animals have not yet been totally 1. COMPLEX excluded. 2. Frequently used in microbiology laboratory setting to describe two or more species whose distinction and of little or no medical importance PATHOGENESIS SPECTRUM OF DISEASE 1. Inhalation of single viable organism lead to 1. Trachoma - chronic inflammation of the infection conjunctiva 2. Ingestions of milk from infected cows, M. bovis 2. Lymphogranuloma venereum –(LGV) STD 3. Attenuated strain M. bovis, bacille Calmette that is characterized by a primary genital lesion Guerin (BCG) immunize susceptible individuals at the initial infection site. against tuberculosis 3. Oculogenital infection – cause acute inclusion conjunctivitis in adults. Tuberculin skin test 4. Perinatal infections – infants develop inclusion - PPD (Purified Protein Derivatives) conjunctivitis. - Patient may develop delayed hypersensitivity cell mediated immunity to certain antigenic SPIROCHETES component of the organisms 1. Treponema NONTUBERCULOUS MYCOBACTERIA 2. Borrelia 1. Other names that have been used to designed 3. Leptospira the Nontuberculous Mycobacteria 2. Anonymous GENERAL CHARACTERISTICS 3. Atypical 1. Long, slender, helically curved, Gram negative 4. Unclassified bacilli 5. Unknown 2. Axial fibrils and outer sheath 6. Tuberculoid 3. Corkscrew like winding 7. Environmental 8. Opportunistic 9. MOTT (mycobacteria other than tubercle bacilli) RUNYOUN CLASSIFICATION OF NTM Runyoun group no. Group Name 1 Photochromogens 2 Scotochromogens 3 Nonphotochromogens 4 Rapid growers NONCUTIVATABLE NTM -M. leprae 1. Hansen’s disease 2. Leprosy 3. Chronic disease of the skin, mucus membranes and nerve tissue Treponema OBLIGATE INTRACELLULAR NONCULTURABLE BACTERIAL AGENTS - Best observed using Darkfield or Phase contrast microscopy Chlamydia trachomatis - Microaerophilic 1. T.pallidum - Association with infertility and ectopic pregnancy 2. T,pallidum subsp. Pertenue - Infects human 3. T.pallidium subsp. Endemicum - Major cause of Pelvic Inflammatory Disease 4. T. carateum (PID) - Ocular trachoma SPECTRUM OF DISEASE - Sexual transmission 1. Treponema pallidum - syphilis 2. Primary syphilis Property C. C. psittaci C. 3. Secondary syphilis trachomatis pneumoniae 4. Late or tertiary syphilis Host range Humans Birds, Humans (except one lower Stages of Syphilis biovar that mammals, 1. Primary Syphilis causes humans o A hardened, painless chancre develops mouse (rare) approximately 3 weeks after exposure. pneumonitis) 2. Secondary Syphilis Elementary Round Round Pear-shaped o The chancre curls inward, and a rash body appears about 4 to 6 weeks after morphology exposure. Inclusion Round, Variable, Round, o The rash resolves within weeks to 12 morphology vacuolar dense dense months. 3. Latent Syphilis Glycogen- o No symptoms are present during this containing Yes No No inclusions stage. o It may last for weeks to years and Plasmid DNA Yes Yes No sometimes persists throughout life. Susceptibility 4. Tertiary Syphilis to Yes No No o Involves CNS, cardiovascular, and other sulfonamides systemic symptoms. o This stage can result in death in severe cases. LEPTOSPIRA TREATMENT - Leptospira interrogans - human leptospirosis 1. Ceftriaxone - Zoonotic disease 2. Penicillin - Common in developing and warm climates 3. Amoxicillin where contact with infected animals or water 4. Doxycycline contaminated with their urine 5. tetracycline - Enter human host through break in the skin, mucous membranes, or conjunctiva. Potential virulence factors of Leptospira 1. Hemolypins 2. Spingomyelinase C and H 3. Fibronectin-binding protein for adhesion and invasion 4. Lipopolysaccharide and outer membrane proteins SPECTRUM OF DISEASE - Symptoms begins 2 to 20 days after infection - Fever, headache, and myalgia 1. Septicemic stage 2. Immune stage ANICTERIC LEPTOSPIROSIS - SEPTICEMIC STAGE - Common clinical syndrome - Self-limiting illness - High fever, and severe headache that last for 3 to 7 days IMMUNE STAGE - Symptoms: onset coincide with the appearance of IgM - Milder than septicemic stage ICTERIC LEPTOSPIROSIS - Aseptic meningitis, Well's disease - Hallmark of immune stage - Most severe illness - Symptoms: Liver, kidney and/or vascular dysfunction with lethal pulmonary hemorrhage - Death occurs in 10% - Clinical presentation of leptospirosis mimic those of many other diseases LABORATORY DIAGNOSIS - 1st 10 days: leptospirosis are present in blood and CSF - 2nd week of illness up to 30 days - urine specimens can be obtained - Avoid collection in citrate anticoagulants DIRECT DETECTION - Darkfield microscopy: blood, CSF and urine - Centrifuge for 30 minutes at 1500 x g, sodium oxycolate or heparin-treated blood is initially spin at 500x g - Other techniques: 1. Fluorescent antibody staining 2. Hybridization techniques using leptospira-apecific DNA probes 3. Conventional and real time PCR assays. SERODIAGNOSIS - Requires fourfold or greater rise in titer of agglutinating antibodies - MICROSCOPIC AGGLUTINATION (MA) - standard agglutination serologic procedures - Indirect hemagglutination - ELISA test for IgM Ab - detectable duing the first week of illness