Bacterial Classification - PDF

Neisseria Family NEISSERIACEAE Gram-negative cocci except N. elongata (rod) Genera Neisseria and Moraxella...

Neisseria Family NEISSERIACEAE Gram-negative cocci except N. elongata (rod) Genera Neisseria and Moraxella Obligate aerobes Characteristics Oxidase-Positive Prefer CO2 – Candle jar Gram Negative Diplococci Nonmotile Capnophilic Catalase POSITIVE except N. elongata Do not use glucose; most do not grow on MacConkey agar but will grow well on BAP and CAP. Oxidase POSITIVE Pathogenic species: N. gonorrhoeae and N. meningitidis Glucose Maltose Sucrose Lactose N. gonorrhoeae Leading cause of STD. M. catarrhalis - - - - Purulent urethritis in male and cervicitis in females (can be asymptomatic). N. gonorrhoeae + - - - Localized infection: pharyngitis, conjunctivitis (ophthalmia neonatorum from infected mother). N. meningitidis + + - - Disseminated: pelvic inflammatory disease may cause sterility, ectopic pregnancy, or N. subflava + + +/- - perihepatitis (Fitz-Hugh–Curtis syndrome) or gonococcal bacteremia. N. lactamica + + - + N. meningitidis Common in adults. Serious, life threatening, acute, purulent meningitis. Moraxella Meningitis with rash (petechiae) associated with meningococcal bacteremia Gram-negative diplococci (meningococcemia). Nonmotile Bacteremia causes thrombocytopenia, DIC, and shock. Catalase POSITIVE Waterhouse-Friderichen syndrome – hemorrhage in adrenal gland. Oxidase POSITIVE Moraxella catarrhalis Localized infection to respiratory tract, includes sinusitis and pneumonia. Not a carbohydrate utilizer Lower respiratory tract infections target elderly patients and patients with chronic obstructive M. catarrhalis after 48 hours, illustrating the “wagon-wheel” appearance on chocolate (CHOC) agar. pulmonary disease. Laboratory Diagnosis N. meningitidis and M. catarrhalis – BAP + CAP + N. gonorrhoeae – enriched CAP with antibiotics Thayer-Martin Contains: antibiotics as inhibitors Vancomycin – inhibits growth of gram positive Colistin – inhibits growth of gram-negative bacteria except N. gonorrhoeae Nystatin - inhibits growth of fungi Modified Thayer-Martin Contains: antibiotics as inhibitors Vancomycin – inhibits growth of gram positive Colistin – inhibits growth of gram-negative bacteria except N. gonorrhoeae Nystatin - inhibits growth of fungi Trimethoprim lactate – prevents swarming of Proteus sp. Martin-Lewis Contains: antibiotics as inhibitors Vancomycin – inhibits growth of gram positive Colistin – inhibits growth of gram-negative bacteria except N. gonorrhoeae Anisomycin - inhibits growth of fungi Trimethoprim lactate – prevents swarming of Proteus sp. New York City Agar Contains: antibiotics as inhibitors Vancomycin – inhibits growth of gram positive Colistin – inhibits growth of gram-negative bacteria except N. gonorrhoeae Amphotericin B- inhibits growth of fungi Acinetobacter – Oxidase NEGATIVE, Grows on MAC Trimethoprim lactate – prevents swarming of Proteus sp. Kingella – Catalase NEGATIVE, Twitching because of pili Eikenella corrodens – Pits or corrodes the surface of the agar, bleach odor. Colonies N. gonorrhoeae Small, gray to tan, translucent, and raised after 24 to 48 hours of incubation. CAP N. meningitidis Medium, smooth round, moist, gray to white; encapsulated strains are mucoid; may be HACEK Group greenish cast in agar. fastidious nutritional requirements and enhanced growth with increased CO2. N. elongata Gray, translucent, smooth, glistening; may have dry, claylike consistency in BAP. M. catarrhalis Large, nonpigmented, opaque, smooth; friable “hockey puck” CAP Haemophilus spp., e.g., H. paraphrophilus Calcium alginate and cotton swabs are inhibitory to N. gonorrhoeae, Dacron and Rayon swab are preferred. N. gonorrhoeae Aggregatibacter actinomycetemcomitans susceptible to drying and temperature changes Cardiobacterium hominis Transport systems: Eikenella corrodens James E. Martin Biological Environmental Chamber (JEMBEC) plates, GONO-PAK, TRANSGROW Kingella spp. KATHRINE JANE CERVANTES, RMT 22 KATHRINE JANE CERVANTES, RMT 23 Gram-Negative Bacilli Antigenic Structures K Antigen ENTEROBACTERIACEAE Capsular antigen, heat labile Gram-negative bacilli, non-spore forming Some Salmonella have capsular antigen (K), referred to as Vi Antigen (Virulence). Facultative anaerobes O Antigen Motile with peritrichous flagella except Klebsiella and Shigella (nonmotile) Somatic antigen, heat stable Catalase POSITIVE except Shigella dysenteriae Antibodies to O antigens are predominantly IgM Oxidase NEGATIVE except Plesiomonas spp Part of lipopolysaccharides of the cell wall. Reduce Nitrate to Nitrite except Erwinia and Pantoea agglomerans H Antigen Glucose FERMENTERS Flagellar antigen Grows well on MAC, if lactose fermenter it produce Pink colonies, if lactose nonfermenter produce colorless colonies. Denatured by heat or alcohol Rapid Lactose Fermenter Late Lactose Fermenter SSCYS Non-Lactose Fermenter SSPPME Agglutinates with anti-H antibodies, mainly LgG EKE Salmonella arizonae Salmonella Escherichia Shigella sonnei Shigella Laboratory Diagnosis Klebsiella Citrobacter Proteus Culture Grows well on 5% sheep blood agar, chocolate agar, and MacConkey agars. Enterobacter Yersinia Providencia Selective agars: Serratia Morganella Hektoen enteric (HE) agar, XLD, Salmonella Shigella. Edwardsiella Eosin Methylene Blue Gram negative bacteria All are Motile at 37’C, EXCEPT: All are GAS producer, EXCEPT: All are Catalase POSITIVE, EXCEPT: Escherichia coli: Lactose fermenter, green metallic sheen SKY PYSS Shigella dysenteriae Other fermenter: Pink colonies Klebsiella Providencia Nonfermenter: Colorless Shigella Yersinia All are Oxidase NEGATIVE, EXCEPT: MAC Selection of Gram Negative and diierentiating ENTEROBACTERIACEAE Yersinia pestis (25-37’C) Salmonella typhi Pleasiomonas shigelloides MAC-Sorbitol Isolate E. coli O157:H7 Yersinia – non motile at 37’C Shigella Hetoen Enteric Agar Detection of enteric pathogens from feces and motile at 25’C All are Xylose fermenter, EXCEPT: Xylose-lysinedeoxycholate Isolates Salmonella and Shigella from stool and other specimen containing except for Y. pestis Shigella spp. mixed flora H2S POSITIVE Diaminase POSITIVE (red slant LIA) Voges Proskauer POSITIVE (acetoin Salmonella-Shigella Selects Salmonella spp and Shigella from stool SPACEd PPM production from butylene glycol) Gram negative broth Enhances enteric bacteria Salmonella Proteus PanSHEK Cefsulodin Irgasan Novobiocin Isolates Y. enterocolitica Proteus Providencia Pantoeae TSI TSI CHO Organism Arizona Morganella Serratia A/A G H2S (-) Lactose and/or sucrose with Escherichia Citrobacter freundii Hafnia Slant (Lactose/Sucrose) - Aerobic (yellow yellow) acid and Gas Klebsiella Edwardsiella Enterobacter Butt (Glucose) - Anaerobic Glucose with acid and Gas Enterobacter LIA : SACEd Klebsiella A – Acidic = yellow K/A G H2S (+) Lactose and sucrose not Citrobacter Rapid Urease Producer produce ammonia beef or raw milk. (NH3) and phenylpyruvic acid Bloody Diarrhea (Shiga-like toxin) Positive: Green color develops on slant after ferric chloride is added Enteroaggregative Persistent watery diarrhea Negative: Slant remains original color after the addition of ferric chloride E.coli (EAEC) MOT not well understood. KATHRINE JANE CERVANTES, RMT 26 KATHRINE JANE CERVANTES, RMT 27 Klebsiella Encapsulated, mucoid colonies Citrobacter Causes UTI and sepsis TSI: A/A (Gas+) (H2S-) ONPG + LDC - IMVic: --++ Proteus Rapid Urease, H2S +, motile Slow Urease producer, nonmotile Indole Negative (P. mirabilis) K. penumoniae – Friedlander’s bacillus (encapsulated, mucoid that tend to string) Produce infections in humans only when they leave the intestinal tract K. oxytoca – IMViC +v++ (indole positive) UTI, bacteremia, pneumonia, nosocomial infections K. ozaenae – purulent sinus infection P. mirabilis and many strains of P. vulgaris exhibit swarming motility (non hemolytic) K. rhinoscleromatis – granuloma of nose and oropharynx Certain strains share specific polysaccharides with some rickettsia (Weil Felix test) and are Enterobacter TSI: A/A (Gas+) (H2S-) agglutinated by sera from patients with Rickettsial diseases IMViC: --++ ◦ OX-2, OX-19 from P. vulgaris LOA Urease negative, motile ◦ OX-K from P. mirabilis LDC – lysine Opportunistic infections, UTI, respiratory tract and wound infection. Providencia Citrate + decarboxylase E.aerogenes LDC + ODC + ADH - Normal intestinal flora ODC – ornithine E.cloacae LDC – ODC + ADH + UTI and occasionally other infections and are often resistant to antimicrobial therapy decarboxylase K. pneumoniae LDC + ODC – ADH – Providencia rettgeri urease positive, P. stuartii urease negative/variable. ADH - Arginine Pantoea LDC – ODC – ADH - Morganella IMViC: ++-- dehydrolase Plesiomonas LDC+ ODC+ ADH+ ODC + Serratia IMViC --++ Edwardsiella IMViC: ++-- slow lactose fermenter H2S Positive ONPG (+) except S. fonticola K/A G+ H2S+ produces extracellular DNase, Lipase, Gelatinase Isolated from the environment and many cold-blooded and warm blooded animals including resistant to many antimicrobials - most clinically significant infection of urinary and respiratory reptiles, freshwater and aquarium fish, frogs and turtles tract, bacterimic outbreaks E. tarda - most human species S. marcescens, S. rubidaea, S. plymuthica To diierentiate from E. coli produces pink-red pigmentation, prodigiosin when incubated at room temperature. ◦ H2S + and Non-lactose fermenter Salmonella IMViC: -+-+ Yersinia pestis Plague - infection of wild rodents transmitted from one rodent to another and occasionally by the TSI: K/A H2S+ bite of fleas (Bubonic plague) / Black death (body discoloration) LDC+ , Motile Broth cultures exhibit a characteristic "stalactite pattern" in which clumps of cells adhere to Sources of infection: water, milk and dairy products, shellfish (from contaminated water), dried one side of the tube or frozen eggs, meat and meat products and household pets Inclusion bipolar bodies in Stain Wayson stain (safety pin appearance) Cause enteritis, systemic infection and enteric fever (typhoid fever) 25’C to 30’C incubation Cause enteric fever: Urease negative ◦ S. paratyphi A (serogroup A) Yersinia Enterocolitis - char by fever, diarrhea and abdominal pain ◦ S. paratyphi B (serogroup B) enterocolytica ◦ Cultured on Cefsulodin-Irgasan-Novobiocin " Bull's eye colonies (also Aeromonas) ◦ S. cholerasuis (serogroup C) Urease (+) ◦ S. typhi (serogroup D) Most common cause of death associated with bacterial contamination of packed RBC ◦ S. typhi (most important cause) Bismuth Sulfite Agar (BSA) - selective for S. typhi (BLACK COLONIES with metallic sheen). OTHER GRAM-NEGATIVE BACILLI Widal test: tube dilution agglutination test. CATALASE POSITIVE GRAM-NEGATIVE BACILLI High titer of O antigen – active infection OXIDASE POSITIVE Vibrio, Aeromonas, Plesiomonas, Chromobacterium High titer of H antigen – past infection or immunization Vibrio Curved comma shaped High titer of Vi antigen – occurs in carriers Polar / peritrichous flagella Shigella IMViC: - + - - Facultatively anaerobic TSI: K/A H2S – Exhibit rapid darting or shooting star motility NLF, H2S (-), nonmotile Oxidase Positive Natural habitat of Shigellae is limited to the intestinal tracts of humans and other primates, Catalase Positive where they produce bacillary dysentery Halophilic (Except Vibrio cholerae and V. mimicus) Dysentery- presence of blood, mucus and pus in stool. Reduce Nitrate to nitrite Shigellosis - Seizures, HUS, associated with S. dysenteriae Vibrio cholerae Characteristic rice water stool Group Catalase ONPG Mannitol Cultured on APW (Alkaline Peptone Water) and TCBS S. dysenteriae A - - - Curved or straight (comma-shaped) gram negative rods S. flexneri B + - + Polar/peritrichous, flagella (Exhibit rapid darting or shooting star motility) S. boydii C + - + Cholera toxin (choleragen) - Increase CAMP S. sonnei D + +, late lactose + ◦ "Pfeipper's phenomenon" - Lysis of V. cholerae after injecting into an immunized host system of GI epithelium = excess loss of water and electrolytes = rice watery stool KATHRINE JANE CERVANTES, RMT 28 KATHRINE JANE CERVANTES, RMT 29  Sucrose fermenter (yellow on TCBS) NONFERMENTING GRAM NEGATIVE BACILLI Sucrose fermenters: V. cholerae, V. alginolyticus - yellow Characteristics ◦ Nonfermenter of glucose (Oxidative) Other Vibrio: Green colonies ◦ Grow in MacConkey as colorless colonies ◦ Fail to acidify O-F Media, overlaid with mineral oil Biotype: EL TOR – new, resistant to Polymyxin B ◦ Fail to acidify TSI Agar Subgroups: ◦ Most isolates are Oxidase Positive ◦ V. cholerae 01 ◦ Most have a characteristic pigment and odor ◦ V. cholerae 0139 ◦ Most are multi-drug resistant ◦ V. cholerae non-01 - strains that phenotypically resemble V. cholerae 01 but fail to Laboratory Diagnosis diierentiate microorganisms based on the ability to oxidize or ferment specific agglutinate in 01 antisera Oxidation and carbohydrates *All share a common flagellar (H) antigen and somatic (0) antigen Fermentation Nonfermentative bacteria are routinely tested for their ability to produce acid from six String Test carbohydrates (glucose, xylose, mannitol, lactose, sucrose, and maltose). Reagent: 0.5% sodium deoxycholate Separate Vibrio spp. from Aeromonas and Plesiomonas Fail to acidify O-F Media, overlaid with mineral Vibrio Gastroenteristis “Summer Diarrhea” Fermentative: Change in color in both tubes. Enterobacteriaceae, Vibrio, Aeromonas, parahaemolyticus Has heat stable hemolysin that lyse human RBC in Wagatsuma agar Plesiomonas and Chromobacterium Vibrio vulnificus Septicemia and wound infections Oxidative: Change in color in tubes w/out mineral oil (Open tube) Acinetobacter, Lactose Positive Vibrio Stenotrophomonas, Pseudomonas, Burkholderia Vibrio alginolyticus Wound infections, strict halophile, sucrose fermenter Asaccharolytic: No change in color in both tubes. Alcaligens, Oligella Vibrio mimicus Gastroenteritis and ear infections associated with marine environment Non-halophilic Pseudomonas Obligate aerobe Sucrose fermentation negative aeruginosa ◦ Motile and rod shaped Aeromonas Aeromonas hydrophilia ("water loving") is the most common isolate (fresh water fish) Grows well at 37°C, its growth at 42 °C will diierentiate it from other Pseudomonas sp. Gram negative straight rods ◦ Oxidase positive Large, round, raised, opaque. B-hemolytic (SBA) Grape-like or "corn tortilla-like" odor resulting from production of 2-aminoacetophenone Ferments lactose, pink-centered colonies in CIN ◦ Does not ferment carbohydrate Plesiomonas Straight gram (-) rods that occurs singly, in pairs, in short chains and filamentous forms Shiny, opaque, smooth, y-hemolytic in SBA Habitat: Environment (soil, water, plants); survives well in domestic environments (e.g., hot White to pink in inositol brilliant green bile salt agar tubs, whirlpools, contact lens solutions) and hospital environments (e.g., sinks, showers, LDC, ODC, ADH Positive " Positive Trio" respiratory equipment); rarely part of normal microbiota of healthy humans. Chromobacterium Violet pigment can interfere with oxidase test violaceum Ammonium cyanide odor Virulence: Exotoxin A, exoenzymes S and T, endotoxin (LPS), proteolytic enzymes, alginate, pili, adhesins; intrinsic resistance to many antimicrobial agents. MICROAEROPHLIC GRAM-NEGATIVE CURVED RODS (Catalase Positive, Oxidase Positive, Urease Positive) Campylobacter C. jejuni, C. coli (associated with gastritis and diarrhea) Opportunistic pathogen; cause of community- or hospital- acquired infections. Microaerophilic and capnophilic, motile, curved or seagull- winged, faintly staining that are Community-acquired infections: skin (folliculitis); external ear canal (otitis externa); eye, associated with gastritis and diarrhea after trauma; bone (osteomyelitis), after trauma; heart (endocarditis) in intravenous drug Optimum temperature for growth 42 - 43 C abusers; and respiratory tract (CF patients). Motility single polar flagellum = darting motility Health care–associated infections: respiratory tract, urinary tract, wounds, bloodstream Culture medium Campy-BAP, Skirrow's medium (bacteremia), and central nervous system. Key pathogen that infects lungs of CF patients. Helicobacter S-shaped, seagull wings, microaerophilic, lophotrichous flagella Mild otitis externa/media “swimmers ear” Associated with peptic ulcer (rapid urease producer) Wound and burns, giving rise to blue green pus Urea breath test - noninvasive test Natural habitat is the human stomach, organism is found in the mucus secreting cells. TSI K/K or K/NC (no change) Pigmented Growth at Growth at Hippurate Catalase Nalidixic Acid Nitrate to Fluorescein (Pyoverdin) - yellow 25°C 42°C Hydrolysis Nitrite Pyocyanin - blue Campylobacter - + + + + + Pyorubin - red jejuni subsp. Pyomelanin - brown/black jejuni Growth at 42°C Helicobacter - + - + - +/- Grows in Cetrimide pylori ◦ (cetyltrimethylammonium bromide) Agar "Serrated confluent growth" Burkholderia mallei Causes: Glanders (horses, cattle) Nonmotile KATHRINE JANE CERVANTES, RMT 30 KATHRINE JANE CERVANTES, RMT 31  Burkholderia “Whitmore's Bacillus'" pseudomallei Causes "Melioidosis" (Vietnamese Time Bomb) Bipolar staining (safety pin) in Gram Stain Identifying characteristics 1. Bipolar staining (safety pin) in Gram Stain 2. Smooth to wrinkled colonies in BAP 3. Wrinkled and deep pink in Ashdown media 4. "Earthy odor" Burkholderia cepacia 2nd most common cause of CF. Foot rots in humans Environment (soil, water, plants); survives well in hospital environment; not part of normal human microbiota; may colonize respiratory tract of patients with cystic fibrosis (CF). FASTIDIOUS GRAM NEGATIVE Virulence: Binding of mucin from cystic fibrosis (CF) patients may be involved. Intrinsic Haemophilus Nonmotile, non sporeforming and facultative anaerobic resistance to multiple antibiotics complicates therapy and may promote organism survival Ferment Carbohydrates (Except for H. ducreyi) in hospital environment. Oxidase and Catalase Positive Capnophilic (5% to 10% CO2 at 35°C to 37°C) up to 3 days OXIDASE and LDC + Reduce Nitrates to nitrite Motile Obligate parasites OF – Yellow Virulence factors: MAC – Pink X factor – Hemin, from degradation of hemoglobin; heat stable. CATALASE POSITIVE, OXIDASE NEGATIVE GRAM-NEGATIVE BACILLI V factor – NAD coenzyme, produced by some bacteria and yeast; heat labile. Stenotrophomonas Oxidase (-), DNAse (+) maltophilia Oxidizer of glucose, strong oxidizer of maltose Lavender green colony "Ammonia-like odor" TSA = yellow pigment ACINETOBACTER SPP. TSI: K/K, Oxidase (-), catalase (+) Nonmotile MAC = Purple colony Blue-grey (cornflower blue) in EMB Drug Resistant ◦ Associated infections and diseases: UTI, wound, diarrhea ◦ Acinetobacter baumanni - Oxidizer/Saccharolytic ◦ Grows at 42 C Haemophilus “Pfilers bacillus” Acinetobacter iwoQi - Non-oxidizer /Asaccharolytic influenzae X and V A. haemolyticus - ß-hemolytic strain Six serotypes: a,b,c,d,e,f ; most frequently encountered in infection: B Virulence factors: Capsule: Antiphagocytic, type b most common. Additional cell envelope factors mediate attachment to host cells. Unencapsulated strains: pili and other cell surface factors mediate attachment. Main cause of meningitis in children