Medical Technology Assessment Program 1 PDF

MEDICAL TECHNOLOGY ASSESSMENT PROGRAM 1 ​ PROF MAIDY MEJORADA | A.Y. 2024-2025 | 4TH YEAR 1st Semester | PRELIMS ​ Sucrose fermenting organism - has growth + it...

MEDICAL TECHNOLOGY ASSESSMENT PROGRAM 1 ​ PROF MAIDY MEJORADA | A.Y. 2024-2025 | 4TH YEAR 1st Semester | PRELIMS ​ Sucrose fermenting organism - has growth + it appears yellow colored colonies LESSON 3: GRAM (-) OXIDASE (+) FERMENTATIVE BACILLI ​ Non-sucrose - they will become green and there will be growth ​ Mixed colonies - there will be a mixture of both yellow Vibrio spp. and green colonies and it usually requires sub-culturing on to other medium GENERAL CHARACTERISTICS ❖​ Facultative anaerobes that will appear as curved/comma (,) ❖​ Motility due to monotrichous flagella ​ One flagellum only. ❖​ Usually found in: Estuarine/brackish/marine water ​ usually cultivated in bodies of water that is why the infection is related to the bodies of water. ​ When we eat contaminated food, drink unsanitized water that could be the natural habitat of the organism. ❖​ Infection is acquired through ingestion of contaminated water, ​ Growth with fermentation (yellow): resists the fresh produce, meat, dairy products, seafood or exposure of presence of inhibitory substance with fermentation of disrupted skin and mucosal surfaces to contaminated water. sucrose ❖​ Usually isolated in stool although rectal swab is preferred in ○​ SF organisms: cases of acute diarrheal illness. ​ V. alginolyticus ❖​ All are motile, catalase (+) ​ V. cholerae ❖​ All are oxidase (+) except: ​ V. metschnikovii ​ V. flurialis ❖​ All species are HALOPHILIC (increasing salt concentration, ​ V. furnisii 8-10%) except V. mimicus and V. cholerae ​ V. metschnikovii ❖​ All are Glucose (+) ​ Growth without fermentation (green/blue-green): NSF ​ They differ with pseudomonas because they are non ○​ V. mimicus fermenter whereas vibrio can ferment glucose. But ○​ V. parahaemolyticus not all of them can ferment other carbohydrates. ○​ V. vulnificus ❖​ All are Lactose (-) except: ​ No growth: ​ V. vulnificus ○​ Aeromonas ○​ Plesiomonas ○​ Chromobacterium CULTURE MEDIUM FOR ISOLATION AND DIFFERENTIATION OF VIBRIO SPP. BIOCHEMICAL TESTS FOR DIFFERENTIATION 1.​ SBA CHOC ​ may produce medium to large colonies ​ may appear smooth and opaque 1.​ OXIDASE: for differentiation of ​ with an iridescent greenish hue ​ (+) Vibrio 2.​ Enrichment medium ​ (-) Enterobacteriaceae ​ Alkaline Peptone Water 2.​ INOSITOL FERMENTATION: for differentiation of: ​ pH 8.4 ​ (+) Plesiomonas ferments inositol 3.​ Selective and differential medium ​ Thiosulfate Citrate Bile Salt Sucrose (TCBS) ​ (-) Vibrio doesn’t ferments ​ Inhibitory substance: 3.​ VIBRIOSTATIC AGENT and STRING TEST: ○​ Bile salt ​ (+/Sensitive) Vibrio ​ Fermentable CHO: ​ (-/Resistant) Aeromonas ○​ Sucrose 4.​ CHO FERMENTATION: ​ pH 8.6 ​ differentiates Vibrio spp. which are fermenters vs ​ Vibrio spp. love to grow on a basic medium ​ pH indicators: Pseudomonas which are non-fermenters ○​ bromothymol blue & thymol blue NOTE: V. metschnikovii = (-) oxidase test, catalase test, NRT THIOSULFATE CITRATE BILE SALT SUCROSE AGAR Vibrio and Similar species: GENERAL CHARACTERISTICS ​ Contains sucrose, Na Citrate and ox gall (bile), and pH ❖​ Facultatively anaerobic indicator (bromothymol blue) ❖​ Fermentative ❖​ Oxidase Positive ❖​ Reduce Nitrate to nitrite ❖​ Most species are susceptible to O/129 ❖​ Most species is positive string test ❖​ Halophilic (except Vibrio cholerae and V.mimicus) 1 MEDICAL TECHNOLOGY ASSESSMENT PROGRAM 1 ​ PROF MAIDY MEJORADA | A.Y. 2024-2025 | 4TH YEAR 1st Semester | PRELIMS VIBRIO CHOLERAE Vibrio vulnificus ❖​ Most clinically significant species ​ Septicemia & wound infections ❖​ Exhibit shooting star motility ​ Only Lactose (+) vibrio spp. ​ Due to its monotrichous ​ Agent of Necrotizing fasciitis (flesh-eating bacteria targeting flagella healthy tissues) ​ Visualize better when you used ○​ T1: V. vulnificus ○​ T2: S. pyogenes a leifson flagella stain ○​ T3: C. perfringens ❖​ Agent of cholera ​ Predisposing factors: Liver dysfunction and increase serum ​ Cholera - a public health concern which was iron prevalent during the earlier times here in the Philippines Vibrio alginolyticus ​ Wound infections VIRULENCE FACTOR AND CLINICAL MANIFESTATION ​ Strict halophile 1.​ Cholera toxin (Choleragen) Laboratory Diagnosis ​ Profuse watery diarrhea ○​ If the patient has ​ Specimen collection & Transport been ○​ Specimens: Body fluids, pus, or tissues complaining ○​ Transport medium: about profused stool ​ Cary-blair for Swabs samples ​ Alkaline Peptone Water for Stool culture ​ Rice watery stool composed of fluids and ​ Culture Media mucous (flicks) ○​ Medium to large, smooth, opaque, iridescent with a ○​ Suspected patient on having cholera greenish hue in SBA (alpha or beta hemolytic) or ​ Leads to dehydration, hypovolemic shock CHOC. ○​ Due to electrolyte imbalance ○​ MAC: produce colorless result 2.​ Somatic antigens 01 and 0139 ○​ TCBS: subculture in TCBS for differentiation ​ Markers for strains capable of ​ Almost always produce cholera toxin AEROMONAS SPP ​ 3 Serotypes: ○​ Ogawa, Inaba, Hikojima A.​ Introduction ​ A. hydrophila is the most common isolate Vibrio & Similar Species ○​ Water-loving because usually isolated in the bodies of water ​ Oxygen Requirement: Facultative Anaerobes Biogroups of V. cholerae 01 Strains ​ (+) result in glucose, oxidase and catalase ​ Stool Pathogen Eltor Classical ​ Ubiquitous, oxidase (+), glucose-fermenter, gram (-) B.​ Virulence Factor Hemagglutination of chicken RBC + - ​ Heat labile and Heat stable cytotoxic enterotoxin C.​ Clinical Manifestation B-hemolysis in sheep’s blood + - ​ A. Intestinal (five diarrheal syndromes) agar ➔​ Secretory (vomiting) ➔​ Dysenteric (w/ blood & mucus) Voges-Proskauer (V-P) Test + - ➔​ Cholera-like (rice water) ➔​ Nebulous (ETEC) Polymxin B (50 U) Susceptible Resistant (S) ​ B. Extraintestinal produce zone ➔​ Wound infection of inhibition ➔​ Septicemia ➔​ Meningitis Clinical Significance CHOLERA AEROMONAS HYDROPHILA ​ Water-loving; most common isolate Vibrio parahaemolyticus ​ (+) Oxidase ​ Gastroenteritis (summer diarrhea) ​ Glucose fermenters ​ Kanagawa toxin positive ​ Gram (-) rod ○​ it is usually associated with the virulence of this organism AEROMONAS CAVIAE ​ Kanagawa phenomenon ​ Non-hemolytic; most common isolate ○​ production of β-hemolysis in a special high(↑) salt ​ Frequently associated with gastrointestinal infections, mannitol medium especially in neonate and pediatric populations with ​ Medium is Wagatsuma agar inflammatory bowel disease 2 MEDICAL TECHNOLOGY ASSESSMENT PROGRAM 1 ​ PROF MAIDY MEJORADA | A.Y. 2024-2025 | 4TH YEAR 1st Semester | PRELIMS Clinical Manifestation Vibrio & Similar Species 2. STRING TEST ❖​ Cellulitis - deeply affects the cells ❖​ Myonecrosis - rotten wound ❖​ Necrotizing fasciitis - flesh eating bacteria ❖​ Ecthyma Gangrenosum ​ Reagent: 0.5% Na deoxycholate ❖​ These are similar infections with infections in Clostridium and ​ Positive: String/long tenacious stringing (common in Vibrio Pseudomonas spp.) ​ Negative: No stringing//no tenacious stringing (Plesiomonas, Laboratory Diagnosis Chromobacterium, & Aeromonas) ​ Gram stain and Culture media characteristics: ​ Gram (-) straight rods, Oxidase (+), Spot Indole (+) 3.​ VIBRIO STATIC TEST ​ Large brown Beta hemolytic ​ Ferment Lactose, and produce pink centered color colony in (CIN - Cefsulodin-Irgasan-Novobiocin medium) for isolation of Yersinia enterocolitica ❖​ Vibriostatic agent: 0/129 = 2,4-diamino-6,7,diisopropyl pteridine ❖​ differentiate Vibrio cholerae vs. other vibrio spp. ❖​ Reagent: 150 µg of 0/129 impregnated disc ❖​ Positive (susceptible) Zone of Inhibition: V. cholerae, P. shigelloides PLESIOMONAS SHIGELLOIDES ❖​ Negative (resistant): Aeromonas spp., other Vibrio spp., C. violaceum ❖​ Clinical Manifestation ​ can cause Git infection, bacteremia, meningitis Salient Features for Identification PLESIOMONAS SHIGELLOIDES V. cholerae V. mimicus Other Vibrio ❖​ Clinical Manifestation TCBS + + + ​ can cause Git infection, bacteremia, meningitis ❖​ Laboratory Diagnosis Sucrose + - V ​ Straight gram (-) rods that occurs singly, in pairs, in short chains and filamentous forms String Test + + + ​ Shiny (γ- hemolytic) in SBA ​ White to pink in Inositol Brilliant green bile salt agar 0/129 (150 g) + + - ​ Lysine Decarboxylase, Ornithine Decarboxylase, & Susc. Arginine Dehydrolysis test “Positive Trio” Broth w/o NaCl + + - Broth w/ 6.5% + + + NaCl Voges Proskauer + - V 3 MEDICAL TECHNOLOGY ASSESSMENT PROGRAM 1 ​ PROF MAIDY MEJORADA | A.Y. 2024-2025 | 4TH YEAR 1st Semester | PRELIMS cross-reactivity of LABORATORY DIAGNOSIS Campylobacter Abs) that usually affects the nerve ganglia that leads to paralysis ​ Cause paralysis is usually due to the infection to the endoneurium of the patient ​ Intestinal walls are acidic in nature ​ Around the GIT, there are infection or bacteria ○​ Bacteria: strong rapid urease producing organism, they give large amunt of ammonia (hour) ​ Due to increase in pH, the acidic of environment would lead to neutralization LABORATORY DIAGNOSIS ​ After the neutralization, the bacteria would penetrate into the intestinal wall ​ If the organism penetrate the intestinal wall = ulceration/bleeding in the GI mucosa CAMPYLOBACTER AND HELICOBACTER: LABORATORY DIAGNOSIS Specimen Collection and Transport ❖​ Campylobacter Jejuni ​ Fecal or feces specimen - uses transport medium such as Stuarts, Cary Blair, and Campythio ❖​ Campylobacter fetus subsp. fetus ​ Blood samples - routine blood culture ❖​ Helicobacter pylori ​ Tissue biopsy - uses transport medium such as Stuarts, Cysteine-Brucella broth with 20% glycerol CAMPYLOBACTER AND HELICOBACTER: CULTURE MEDIA AND INCUBATION ❖​ Campylobacter ​ Campy-BAP, Skirrow’s, Butzler and CCDA ​ 42c pr 37c at 85% N2, 5% O2, and 10% CO2 ❖​ Helicobacter ​ Skirrows, CHOC agar or Brucella agar with 5% horse RBC ​ 42c at 5-10% O2, and 5-12% CO2 CAMPYLOBACTER AND HELICOBACTER Campylobacter and Helicobacter Culture media and Incubation ❖​ Campylobacter GENERAL CHARACTERISTICS ​ Camp-BAP, skirrow’s, Butzler and CCDA ​ Oxidase positive ​ 42 deg or 37 deg at 85%N2, 5% O2, and 10% CO2 ​ Most species are asaccharolytic ​ microaerophilic; reduce amount of oxygen ​ Small, curved, motile, gram (-) bacilli needed ​ Microaerophilic (they need reduced amount of oxygen for their ❖​ Helicobacter growth and survival) ​ Skirrow’s, CHOC agar or brucella agar with 5% horse RBC CAMPYLOBACTER JEJUNI ​ 42 deg at 5%- 10% O2, and 5%-12% CO2 ​ lecturer’s side notes a.​ Epidemiology ​ Abortion in domestic animals ○​ Due to ingestion of contaminated water Campylobacter and Helicobacter and poultry microscopic morphology ​ Exposure to animals and pets b.​ Clinical Manifestations ​ Most common cause of BACTERIAL ❖​ Campylobacter GASTROENTERITIS ​ S SHAPE; resembles wings of seagulls ○​ Self-limited in most patients ​ Darting motility ○​ One of the causes of complicated ❖​ Helicobacter Guillain-Barre syndrome ​ Multiple Flagella at one pole ​ Guillain-Barre syndrome ○​ Autoimmune disorder ​ Involves the antibodies of Campylobacter (or 4 MEDICAL TECHNOLOGY ASSESSMENT PROGRAM 1 ​ PROF MAIDY MEJORADA | A.Y. 2024-2025 | 4TH YEAR 1st Semester | PRELIMS Campylobacter and Helicobacter Colony Morphology ❖​ Campylobacter spp. ​ Moist “runny” looking and spreading (C. jejuni) ​ Smooth Convex and translucent (C. Fetus) ❖​ Helicobacter pylori ​ Small translucent, circular colonies DEFINITIVE IDENTIFICATION C. Jejuni C.fetus H. pylori subsp. jejuni subsp. fetus Hippurate hydrolysis + – – Growth at 42ºC + – V Growth at 25ºC – + – Urease – – + Nalidixic acid S R R Cephalotin R S S Notes: ❖​ H. Pylori is a strong urease producing organsm. The test itself (urease test) is distinct to helicobacter pylori. ❖​ For the 2 antibiotics (nalidixic acid & cephalotin) susceptibility testing Definitive Identification for Helicobacter pylori ❖​ Urease Test ​ Tissue(Gastric biopsy) placed in Christensen Urea medium ​ Incubate: 37 C for 2hrs ​ Positive Result: Pink ❖​ Urea Breath Test(nonculture/noninvasive) ​ Absorbed in bloodstream then exhaled ​ Detected by scintillation counter ​ 13C or 13C labeled urea (oral) ​ Urease- 13CO2 or 14CO2 5