Chapter 14-16 Microbiology PDF

CHAPTER 14: 2. Localized and systemic infections. CATALASE (-) GRAM (+) COCCI 3. Involvement of deeper tissues and organs- General characteristics of Streptococcus sp. and “flesh-eating bacteria” Enterococcu...

CHAPTER 14: 2. Localized and systemic infections. CATALASE (-) GRAM (+) COCCI 3. Involvement of deeper tissues and organs- General characteristics of Streptococcus sp. and “flesh-eating bacteria” Enterococcus sp.: POST STREPTOCOCCAL INFECTIONS Catalase negative RHEUMATIC FEVER: ACUTE GLUMERULONEPHRITIS: Gram (+) cocci appearing singly or in pairs -Fever -Edema and chains -Carditis -Hypertension Facultatively anaerobic -Subcutaneous nodules -Hematuria Varying hemolytic patterns α (alpha), β polyarthritis (beta) & γ (gamma) -Proteinuria Nonmotile Colonies- Most are small to medium circular and entire and range from S. pneumoniae transparent to off white or gray. Primary cause of bacterial pneumoniae, COMMON PATHOGENS meningitis and otitis media. S. pyogenes (group A) Capsule-virulence S. agalactiae (group B) Inhabit respiratory tract S. pneumoniae Life threatening infection Enterococcus faecium OTITIS MEDIA (MIDDLE EAR INFECTION) Enterococcus faecalis Viridans streptococci Bacterial Causes: - Streptococcus pneumoniae, a Gram (+) diplococcus. - Haemophilus influenzae, a Gram (-) bacillus. - Moraxella catarrhalis, a Gram (-) diplococcus. Viral Causes: Measles, parainfluenza, and respiratory syncytial (RSV) viruses (RSV) Often develops as a complication of common cold. Rupture eardrum, bloody discharge, & pus. PATHOGENESIS AND SPECTRUM OF DISEASE STREPTOCOCCAL ENZYMES BETA- HEMOLYTIC STREPTOCOCCI Streptolysin O Streptococcus pyogenes Streptolysin S FACTORS CONTRIBUTE FOR VIRULENCE: Streptokinase Dnase 1. Streptolysin O and S- responsible for beta Hyaluronidase hemolytic pattern for BAP. MAMM 1  VIRIDANS (GREENING) STREPTOCOCCI & REBECCA CRAIGHILL LANCEFIELD, 1895-1981 Abiotrophia Lancefield’s group classification. Formally known as nutritionally variant Simple serological test streptococci. Distinguished between the streptococci Transient bacteremia and endocarditis in associated with the human disease (group immunocompromised patients. A) and those chiefly associated with infections of domestic animals (groups B & ENTEROCOCCI C). Intrinsically more resistant to antimicrobial agents. LANCEFIELD CLASSIFICATION First clinically relevant group of Gram (+) (CARBOHYDRATE COMPOSITION ON THEIR cocci to acquire and disseminate resistant CELL WALL) to Vancomycin. Group A- rhamnose-N-acetylglucosamine Group B- rhamnose-glucosamine 2 SPECIES: polysaccharide E. faecalis Group C- rhamnose-N-acetylglucosamine E. faecium Group D- glycerol teichoic acid containing alanine & glucose. S. agalactiae Group F- glucopyranosyl-N- Neonates acetylgalactosamine Acquire before or during the birthing process. CLASSIFICATION TABLE SEROLOGIC BIOCHEMICAL HEMOLYTIC PATTERN A S. pyogenes Beta B S. agalactiae Beta, Alpha, Gamma C S. equisimilis Beta D S. bovis Alpha, Gamma S. faecalis Alpha, Beta, Gamma F S. milleri Alpha, Beta, Gamma G S. milleri -do- - S. pneumoniae Alpha VIRIDANS S. salivarius, S. Alpha, Gamma sanguis, etc. VIRULENCE FACTORS 1. Capsule- non-immunogenic 2. M. protein- hair-like projections on the cell wall - Major virulence factor - Promotes adherence - Antiphagocytic - Anticomplement - Type specific 3. Lipoteichoic acid- for adherence LANCEFIELD CLASSIFICATION 4. Erythrogenic toxin- pyrogenic exotoxins A, Serological classification of beta-hemolytic B, C streptococcal bacteria. - Responsible for the rash of Scarlet fever Based on the carbohydrate composition of 5. Streptolysin O- lyses WBC, platelets, RBC bacterial antigens found on their cell walls. - Immunogenic Lancefield group antigen does not 6. Streptolysin S- non-immunogenic correlate with the species. - Responsible for the hemolytic zones around colonies. MAMM 2  7. Streptokinase (fibrinolysin)- lyze blood - “strawberry tongue” clots → plasminogen → plasmin → digest 7. Pneumonia- rapidly progressive & severe fibrin & other proteins - Most commonly a sequela to viral - Facilitates spread of infection infections like influenza or measles. - Used in the treatment of pulmonary NON-SUPPURATIVE SEQUELAE emboli & coronary artery & venous 1. Rheumatic fever- associated with M types thromboses causing URI & skin infections 8. DNAse (streptodornase)- depolymerizes - Fever, malaise, migratory cell-free DNA in purulent materials. nonsuppurative polyarthritis, evidence 9. Hyaluronidase- spreading factor of inflammation of the heart. - Splits hyaluronic acid - Carditis → leads to thickened & ❖ Streptodornase & streptokinase → used in deformed valves & to small perivascular enzymatic debridement → liquefy granulomas in the myocardium (Aschoff exudates & facilitate removal of pus & bodies) necrotic tissue → antibiotics gain better 2. Acute Glomerulonephritis- associated access. with M types producing URI & skin infections CLINICAL SYNDROMES - Particularly associated with types 12, 4, SUPPURATIVE INFECTIONS 2 & 49 which are nephritogenic. 1. Skin Infections - Initiated by ag-ab complexes on the a. Impetigo- superficial blister covered glomerular basement membrane with pus or honey-colored crust. - Hematuria, proteinuria, edema & b. Erysipelas- acute superficial cellulitis hypertension. of the skin with lymphatic involvement DIAGNOSIS 1. Microscopy STREPTOCOCCAL SKIN INFECTIONS 2. Culture- Bacitracin Test (Taxos-A) Erysipelas 3. Antigen detection test- Enzyme- linked Impetigo immunosorbent assay (ELISA) or agglutination tests. INVASIVE GROUP A STREOPTOCOCCAL INFECTION 4. Antibody detection - ASO titer- for respiratory disease Streptokinases - antiDNAse & antihyaluronidase- for skin Hyaluronidase infection. Exotoxin A, superantigen Cellulitis MISCELLANEOUS OTHER GRAM (+) COCCI Necrotizing fasciitis Low virulence 2. Pharyngitis- most common infection Associated with infection involving - Nasopharyngitis, tonsilitis, purulent compromise patients. exudates, cervical lymphadenopathy & Exception: high fever. - Alloiococcus otitidis with chromic otitis 3. Sepsis- follows infection of traumatic or media in children surgical wounds. - Leuconostoc spp. & pediococcus- can 4. Puerperal Fever- occurs ffg delivery survive hospital environment. 5. Acute Endocarditis- occurs in previously LABORATORY DIAGNOSIS deformed heart valves. Specimen Collection and Transport- No 6. Scarlet fever- a complication of special consideration is required. pharyngitis if the causative agent can Specimen Processing- No special produce erythrogenic toxin. consideration is required. - Initial symptoms of pharyngitis, diffuse erythematous rash with sparing of the DIRECT ANTIGEN DETECTION palms & soles. Latex agglutination - Circumoral pallor Coagglutination MAMM 3  ELISA SEROLOGIC GROUPING Lancefield precipitin test THROAT SWAB PYR and Hippurate or CAMP test 2 throat swabs from each patient Bile solubility test- confirmatory 1st swab- if positive for direct antigen method, 2nd swab discarded. CAMP TEST If negative for Direct Antigen Method, the Detects production of diffusible, 2nd swab should be inoculated on BAP or extracellular protein that enhances the selective streptococcal blood agar. hemolysis of sheep erythrocytes by Staphylococcus aureus. NEONATAL SEPSIS & MENINGITIS Commercial antigen detection kits SERODIAGNOSIS Specimen: serum, urine, CSF S. pyogenes Latex agglutination- most sensitive and ASO (antistreptolysin O) specific Anti- DNase B Vaginal swab for suspected S. agalactiae Antistreptokinase LATEX AGGLUTINATION KITS Antihyaluronidase Detect the capsular polysaccharide Streptozyme- which detects a mixture of antigen of the pneumococcus antibodies. No longer commonly used in micro lab. ANTIMICROBIAL SUSCEPTIBILITY TESTING GRAM STAIN Penicillin- drug of choice Gram (+) cocci; round or oval shaped, PREVENTION elongated cells that resemble pleomorphic Single does 23-valent vaccine corynebacteria or lactobacilli. (Pneumovax)- to prevent ion by most They may appear as Gram (-) if culture is common serotypes of S. pneumoniae. old or patient has been treated with Vaccination is recommended for individual antibiotics. older than 65 y/o and for patients with: Growth in broth should be used if there is 1. Chronic pulmonary, cardiac, liver, or renal a question regarding staining disease characteristics from solid media. 2. No spleen (asplenic) - Strep- like Gram stain 3. Sickle cell disease - Staph- like Gram stain 4. Diabetes CULTIVATION (MEDIA) 5. HIV infection 5% sheep BAP 6. Immunocompromised patients Chocolate agar Heptavalent (seven serotypes)- Prevnar- CAN (Columbia agar with colistin & available for children younger than 2 y/o. Nalidixic acid) Account for majority of cases if PEA (Phenylethyl alcohol agar) bacteremia, meningitis, and otitis media in 5% sheep blood supplemented with younger children younger than 6 y/o. trimethoprim-sulfamethoxazole Lifetime prophylaxis with Penicillin Todd Hewitt broth with antibiotic Given either monthly (IM) or LIM broth Daily (oral)- for patients with rheumatic heart disease to prevent development of INCUBATION CONDITIONS & DURATIONS bacterial endocarditis on damaged heart BAP should be inoculated by stabbing the valve. inoculating loop into the agar several times Penicillin is indicated to control outbreaks to enhance visualization of beta hemolysis of S. pyogenes in individual in close to enhanced anaerobic conditions. physical contact, such as in households, Colonies can then grow throughout the military populations, newborn nurseries. medium, producing substrate oxygen- sensitive hemolysins (streptolysin O). MAMM 4  CHAPTER 15: BACILLUS AND SIMILAR WOOLSORTER’S DISEASE & RAGPICKER’S ORGANISMS DISEASE General Characteristics Used to describe respiratory infections that result from exposure to endospores Large, gram (+) bacilli, spore-forming rods during the handling of animal hides, hair, - Some species do not produce or fibers and other animal products. endospores Bacillus anthracis INFECTIONS (Cont.) Catalase positive Are opportunistic Aerobic Are associated with food-borne illness: Nonhemolytic on 5% sheep blood agar - Toxin mediated Colonies appear dry and irregular - Diarrhea and abdominal pain Ground glass or “Medusa” head - Nausea and vomiting appearance of colonies (B. anthracis) Can cause progressive endophthalmitis Sensitive to penicillin Bacillus anthracis VIRULENCE FACTORS EPIDEMIOLOGIC FACTORS Plasmid-borne toxins Bacillus sp. primarily cause disease in wild - Lethal Toxin (LT) and domestic animals (herbivores). - Edema Toxin (ET) Species is found in soil Loss of toxin encoding plasma attenuates Humans acquire infections when or reduces the pathogenesis of the inoculated with endospores organism. - Traumatic introduction - Ingestion Bacillus anthracis - Inhalation Most notorious pathogen - Injectional Inhabits the soil B. anthracis produces endospores, which Inhalation during exposure to are highly resistant to heat and desiccation contaminated animal products such as Endospores remain dormant until they are hides, or traumatic introduction. deposited in a suitable environment for PREVENTION AND TREATMENT growth. Avoid exposure Bacillus anthracis INFECTIONS Anthrax is a treatable disease Cutaneous TYPES OF ANTHRAX - Is the majority of infections - Inoculation od endospores occurs through a break in skin. - Produces a black, necrotic, painless lesion, called an eschar. Gastrointestinal - Endospores are ingested - Routed of transmission include oral or oropharyngeal. - Significant mortality resulting from toxemia and sepsis. Inhalation (Woolsorters’ disease) - Is due to the inhalation of endospores Bacillus cereus from exposure to animals Previously a single clinically relevant - Spreads to lymph nodes before species. becoming systemic Widely distributed in nature within the soil - Patients demonstrate abnormal chest x- and associated with contaminated drugs of ray images. abuse Clinical presentation - Localized skin infections MAMM 5  - Food poisoning B. cereus CULTURE MEDIA - Systemic disease (bacteremia, 5% sheep blood agar septicemia, and endocarditis) Chocolate agar Virulence factors Columbia colistin-nalidixic (CNA) agar - Hemolysis BL (HBL) - Isolates susceptible to nalidixic acid will - Nonhemolytic enterotoxin (Nhe) not grow. - Cytotoxin K Phenylethyl alcohol - Cereulide toxin Bicarbonate agar - Induces capsule formation in B. SPECIMEN COLLECTION AND PROCESSING anthracis May be handled under standard laboratory Mannitol- egg yolk- polymyxin (MEYP or practices except procedures that may MYP), polymyxin- egg yolk- mannitol- produce aerosols, food products, and bromothymol blue agar (PEMBA), Bacillus animal or environmental samples for the chromogenic media (BCM) - Media containing different mixtures of isolation of B. anthracis. egg yolks, mannitol, and polymyxin B No special processing considerations for especially isolate B. aureus. most species Suspected anthrax; prior to beginning INCUBATION CONDITIONS AND GROWTH antibiotic therapy Growth is typically evident within 24 hrs. - Cutaneous 35*C o Vesicular fluid or punch biopsy Ambient air or 5% CO2 o Biopsy should be placed in 10% Bicarbonate agar requires incubation in formalin CO2 Inhalation DIFFERENTIATION - Blood cultures Differentiation among Bacillus, - Pleural fluid Brevibacillus, and Paenibacillus are based - Serum specimen (serology) on: Gastrointestinal - Size of vegetative cell - Blood cultures - Sporulation resulting in swelling of the - Ascites fluid vegetative cell - Material from any lesions - Biochemical analysis, including the production of lecithinase. - Serum specimen (serology) Bacillus thuringiensis IDENTIFICATION B. thuringiensis has been identified Growth patterns on media: harboring the genes of the B. cereus- - B. anthracis is y-hemolytic on sheep associated enterotoxins. blood agar. Occupational exposure with insecticides - Majority of other species are B- and pesticides containing the organism has hemolytic. resulted in the identification of the Gram stain- Gram (+) rods are organism in the feces without the characteristic; may appear gram variable presence of gastrointestinal symptoms. due to the presence of endospores. Additional rare cases of wound, burn, Produces endospores—Clear oval pulmonary, and ocular infections have structures found intra- or extracellularly. been attributed to B. thuringiensis. Has vegetative cell width Direct detection is accomplished using molecular and antigen-based methods Commercial biochemical identification systems are often used to distinguish species. MAMM 6 Bacillus subtilis, Brevibacillus and EPIDEMIOLOGY Paenibacillus spp. Bacillus subtilis Identified in clinical specimens in a variety of cases including pneumonia, bacteremia, septicemia, surgical wounds, meningitis following head trauma, and other surgical infections. Rare human infections have been associated with a variety of Bacillus spp. Including B. clausii, B. licheniformis, B. coagulans, B. pumilus, Paenibacillus PATHOGENESIS AND SPECTRUM OF DISEASE polymyxa, and Brevibacillus sp. Identification of these organisms is not recommended unless isolated from a sterile site (e.g., blood) or found in large numbers in pure culture. EPIDEMIOLOGY Most other Bacillus spp. is generally considered to be opportunistic pathogens of low virulence and are associated with immunocompromised patients following exposure to contaminated materials. MOLECULAR METHODS Rapid amplification assays - PCR of chromosomal or virulence plasmid genes DIRECT DETECTION METHODS Multilocus sequence typing or variable No specific procedures number of tandem repeats Gram (+) young cultures - Capable of species discrimination Gram variables or gram (-) with age DNA microarrays Ability to produce spores in the presence - Single nucleotide polymorphisms of oxygen. - Strain staining INDUCE SPORULATION MALDI- TOF MS TSI - Distinguishes endospores from other Urea agar materials. Nutrient agar containing 5mg manganese - Identification of B. anthracis sulfate per liter. ANTIBIOTIC THERAPY AND PREVENTION GRAM STAIN Chemoprophylaxis with ciprofloxacin with Spores appear clear because they do not an aminoglycoside is recommended for retain crystal violet or safranin. severe cases of anthrax. Most strains of B. anthracis are susceptible MALACHITE GREEN to penicillin; however, may express Specific dye such as malachite green, inducible B-lactamases. which is forced into the spores using Other species are resistant to penicillin and heat. cephalosporins. Vegetative cells are then Cell-free inactivated vaccine counterstained with safranin. - Three primary doses (0 weeks, 1 month, 6 months) - Two boosters (12 months and 18 months) MAMM 7  CULTIVATION SENTINEL LABORATORY PROTOCOLS MEDIA OF CHOICE Require that each institution rule out 5% Sheep’s blood possibility of anthrax before reporting out CAP any blood cultures. Routine culture media B. subtilis should be suspected if typical Nutrient broth nonhemolytic “Medusa head” colonies are PEA- useful for the isolation of Bacillus spp. observed on 5% sheep’s blood and non- from contaminated specimens. motile. 2 SPECIAL MEDIA FOR ISOLATION OF B. RED LINE ALERT TEST anthracis FDA cleared immunochromatographic test PLET (Polymyxin- lysozyme EDTA- thallous that presumptively identifies B. anthracis acetate) from BAP. - Used for isolation from contaminated Portable anthrax testing with lab-in-a- specimens. pocket BICARBONATE AGAR Sentinel laboratory anthrax was revised in - Used to induce capsule formation 2005 to permit clinical microbiology laboratories who buy this, or any other COLONIAL APPEARANCE FDA cleared test to perform this testing to rule out nonhemolytic nonmotile Bacillus spp. that are not B. anthracis. B. cereus Penicillin resistant Beta hemolytic, motile Produces wide zone of lecithinase on egg yolk agar. B. cereus endophthalmitis is an emergency and should be reported to the physician immediately. B. anthracis (BAP) SERODIAGNOSIS Medium, large, gray, flat Indirect hemagglutination and enzyme- Irregular with swirling projections linked immunosorbent assay are available (Medusa head). to detect Ab to B. anthracis. ANTIMICROBIAL SUSCEPTIBILITY TESTING AND THERAPY B. cereus (BAP) Penicillin- preferred therapy for anthrax Large, feathery spreading Threat of bioterrorism has spawned Beta hemolytic interest in the development of in vitro testing antimicrobial agents. PREVENTION CELL- FREE INACTIVATED VACCINE B. subtilis (BAP) - Given 6 doses (0,2,4,6 weeks, 12 Large, flat, dull, with ground glass months and 18 months) appearance. - Annual booster Maybe pigmented CIPROFLOXACIN OR DEOXYCLINE Maybe beta hemolytic - Minimum of 4 weeks is recommended after aerosol exposure to B. anthracis. COMMENTS REGARDING SPECIFIC ORGANISMS Vegetative width of B. anthracis, B. cereus and B. mycoides do not swell the cell. MAMM 8  CHAPTER 16: immunocompromised and in older LISTERIA, CORYNEBACTERIUM AND adults. C. pseudotuberculosis SIMILAR ORGANISMS - Zoonotic infections, suppurative granulomatous lymphadenitis. GENERAL CHARACTERISTICS EPIDEMIOLOGY Corynebacterium spp. Gram (+) rods Catalase positive Non-acid-fast Non-spore forming Growth on 5% sheep blood agar Some species will not grow in chocolate agar Lipophilic species grow larger with 1% Tween 80 EPIDEMIOLOGY Most organisms are part of the normal human microbiome VIRULENCE FACTORS Notable pathogens C. diphtheriae toxin producing strains Corynebacterium diphtheriae Not all strains are toxigenic o Respiratory Contain bacteriophage that harbors the o Exudates from skin lesions tox gene L. monocytogenes - Blocks protein synthesis resulting in cell o Widely distributed in nature death. o Contaminated food including - Formation pseudomembrane in the oral milks, raw vegetables, cheese, pharynx or nasopharynx. and meat. - Toxin spreads hematogenously causing o Vertical transmission systemic organ damage. transplacentally or through - May lead to cardiac arrest infected birth canal. Health care- associated infections PATHOGENESIS AND SPECTRUM OF DISEASE Corynebacterium jeikeium, Corynebacterium urealyticum, Corynebacterium amycolatum, and Corynebacterium striatum Environmental Rhodococcus spp. - Water, soil and manure of herbivores CLINICAL SIGNIFANCE C. diphtheriae - Pharyngitis with exudative membrane; toxin production. C. jeikeium - Septicemia, skin infections, and LIPOPHILIC infections in those who are Term used to describe lipid-loving bacteria immunocompromised. That grow larger colonies when grown on C. ulcerans 5% sheep blood agar supplemented with - Bovine mastitis; associated with 1% Tween 80 diphtheria-like sore throat C. urealyticum - Urinary tract infections (UTI) and wound infections in those who are MAMM 9 Corynebacterium diphtheriae CULTIVATION - Tissue culture cell test and If C. diphtheriae is suspected, then neutralization of cytopathic effect. selective and differential media should be - Enzyme immunoassays. used. On Loeffler medium, colonies will be gray to white. C. diphtheriae will produce a halo on the following media: Cystine- tellurite blood agar - Cystine enhances growth of fastidious organisms. - Potassium tellurite inhibits normal flora. Modified Tinsdale (TIN) agar - Organisms are differentiated, based on Corynebacterium diphtheriae MOLECULAR the conversion of the tellurite to METHODS tellurium (change in color from grey to Nucleic acid-based methods black) - Ribotyping - Pulsed-field gel electrophoresis 2 CULTURE MEDIA OF CHOICE - Multilocus sequence typing Cystine tellurite BAP - Various PCR amplification tests Modified Tindale’s agar MALDI- TOF MS In addition, Loeffler’s medium containing - Available for identification in dairy serum and egg, products. Stimulates the growth of C. diphtheriae - Limited availability in clinical and production and metachromatic diagnostics. granules. Corynebacterium diphtheriae TREATMENT Immunization - Multidose diphtheria toxoid is available - Four combination vaccines currently available (Dtap, DT, Tdap, and Td). - Previously immunized contacts should receive a booster dose. - Nonimmunized contacts should begin the immunizations. Treatment - Hyperimmune antiserum, diphtheria APPROACH TO IDENTIFICATION antitoxin (DAT); not available in the US Only clinically relevant isolates should be - Intramuscular dose of penicillin identified. - Oral erythromycin (14 days) - Isolation from normally sterile site - Diphtheria - Multiple positive blood cultures - Isolation in pure culture or predominant organism from symptomatic patient. - No other potential suspected etiologic agent isolated. - Isolation from urine as a pure culture >10,000 CFU/mL or predominant organism >100,000 CFU/mL Corynebacterium diphtheriae SEROLOGIC TESTING Several toxin detection methods are available: - Guinea pig lethality test - Immunodiffusion test (ELEK) MAMM 10  Listeria monocytogenes Localized infections Presumptively identified, based on - Conjunctivitis, skin infections, and motility: lymphadenitis. - Direct wet mount (end-over-end - Gastroenteritis associated with food- tumbling). borne outbreaks. - Umbrella-shaped pattern on semisolid agar. VIRULENCE FACTORS Ferments glucose Listeriolysin O Catalase positive - Pore forming toxin that reduces T-cell responsiveness Voges- Proskauer positive - Enables the organisms to escape the Esculin positive phagosome and avoid intracellular Positive Christie, Atkins, Munch- Petersen killing entering the bloodstream (CAMP) test Phospholipases Narrow zone of B-hemolysis - Assists in the process of escaping the phagosome Bacterial surface protein (Act A) - Induces host cell actin polymerization - Promotes cell-to cell spread of the organism allowing the bacteria to eventually reach the central nervous system or placenta. SPECIMEN PROCESSING Isolating L. monocytogenes from placental APPROACH TO IDENTIFICATION and other tissues may be difficult. MULTIPHASIC APPROACH- required for Cold enrichment is used to enhance definitive identification (Reference lab) recovery Specimen is inoculated into a nutrient broth and incubated at 4*C for several weeks to months. COLD ENRICHMENT Coryneform are present as normal flora. A technique used for the enhanced Indicators of clinical relevance include: recovery of Listeria monocytogenes and - Isolation from normally sterile sites other bacteria in which the specimen is - Multiple blood culture bottles placed in a nutrient broth at 4*C for several - Isolation from pure culture weeks to months and subculture at - Predominant organism from frequent intervals. symptomatic patients METHODS BY WHICH TOXINS CAN BE - Isolation from urine if present as pure PERFORMED: culture. UTI INFECTION Coryneform if the pH of the urine is alkaline. There are struvite crystals in sediments. API CORYNE STRIP/ RAPID CB PLUS Rapid identification Misidentification can occur if the code generated CLINICAL SIGNIFANCE Listeriosis systemic disease - Still birth or neonatal death. - Meningitis, bacteremia, encephalitis, and endocarditis. MAMM 11  ELEK TEST C. jeikeium/ C. urealyticum These 2 species are also resistant to several antibiotics’ w/ vancomycin being the only drug demonstrating inhibition of growth. Enhancement of growth by lipids (Tween 80 or serum). Listeria monocytogenes Presumptive identification by observation of motility by direct wet mount Umbrella shaped pattern. Listeria monocytogenes MOLECULAR METHODS Rapid identification in dairy products. Source tracking PCR methods - Listeriolysin O (hly gene) Not currently available in clinical diagnostic laboratories Listeriolysin O detection in cerebral spinal fluid and tissue is possible. TREATMENT AND PREVENTION Typically, no resistance identified to therapeutic agents; therefore, routine sensitivity testing is not warranted. Leftover and ready-to-eat food should be heated before consumption and stored for a short period, L. monocytogenes is able to replicate at 4*C Patients who are immunocompromised and women who are pregnant should avoid eating soft cheeses: - Mexican-style cheese - Feta - Brie - Camembert - Blue-veined cheese MAMM 12