Answers on Determinative Bacteriology Flashcards
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| GBS commonly colonizes what areas? |
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| Lower GI tract and Vaginal epithelium of healthy adults. |
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| The first GBS strain was studied by whom? |
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| Rebecca Lancefield. |
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| First GBS strains studied by Lancefield were isolated from what? |
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| Cows with mastitis. |
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| First report of GBS in humans appeared in what year? |
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| 1938 |
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| What is the gram stain and morphology of GBS? |
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| Gram positive cocci in chains. |
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| GBS Example Species? |
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| Streptococcus agalactiae |
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| GBS hemolysis? |
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| Beta |
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| GBS: Bacitracin, R or S? |
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| Resistant |
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| What is taxonomy? |
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| Systematic categorization of organisms into a coherent scheme. |
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| A taxon... |
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| Provides order, organisms with a common characteristic are recognized and assigned to the same group or rank (taxon). |
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| Linnaeus (1753) classification... |
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| 2 kingdoms, Animalia (animals and protozoa) and Plantae (plants, algae, bacteria, fungi) |
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| Haeckal (1866) classification... |
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| 3 kingdoms, Animalia (animals), Plantae (plants, multicellular algae), and Protista (unicellular algae, bacteria, fungi, protozoa). |
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| Whittaker (1969) classification... |
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| 5 Kingdoms, Animalia (animals), Plantae (plants), Protista (algae, protozoa), Fungi (fungi), Monera (prokaryotae). |
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| Woese (1981) classification... |
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| 3 domains, Archaea, Bacteria, Eukarya |
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| Linnaeus and Haeckel classified organisms based on... |
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| microscopic observations. |
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| Whittaker (1969) classified organisms based on what? |
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| (1969) Improvements in microscopy and biochemical methods. |
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| In 1981 Woese classified organisms based on... |
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| 16s rRNA sequences. |
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| Classical approach to classification assigns microorganisms based on... |
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| morphology and physiology |
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| Numerical taxonomy groups microorganisms ... |
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| into phenoms based on their similarities |
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| Molecular classification is based on... |
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| nucleic acid comparisons |
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| Classical Approach of classification: Structure/Morphology What do they look at? |
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| Shape, size, arrangement, sheaths, flagella and their arrangement, Gram stain, spores). |
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| Classical Approach of classification: Biochemical/physiological. What do they look at? |
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| carbohydrates utilized, optimum temp.m rand of temp. optimum pH, range of pH, growth factors required, O2 requirement, end product fermentation, antibiotic sensitivities. |
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| The numerical approach to classification is based on the work of whom? |
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| French botanist Michael Adanson. |
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| Explain the numerical approach of classification. |
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| All observable characteristics carry equal weight. Similarities between 2 or more organisms are determined using 2 methods. Both methods compare the number of identical characteristics to the total number of characteristics observed in the organisms. |
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| Phenoms are clusters based on the _________ approach to classification. |
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| Numerical |
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| What is used to determine DNA homology between two organisms? |
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| Nucleic Acid Hybridization |
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| Name some different molecular approaches to classification... |
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| Base sequence analysis, DNA probes, 16s rRNA analysis, nucleic acid hybridization, Mol % G/C. |
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| How are phylogenic trees developed? |
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| From 16s rRNA analysis |
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| Why is 16s rRNA used to make phylogenic trees? |
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| Because there are highly conserved regions, the slight differences can determine phylogenic relationships. |
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| Give an example of taxonomic ranks.... |
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| Kingdom, division, class, order...etc Family, Genus, Species,...biovar Serovar, pathovar, morphovar... |
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| What forms on your shower curtain? |
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| Biofilm |
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| What causes pink colonies to form on your shower curtain? |
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| Methalobacteria-utilizes single carbon sources |
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| What causes yellow colonies on the shower curtain? |
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| Sphingomonas->found in dental water lines and AC lines. |
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| Describe the GRAM POSITIVE cell wall. |
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| Thick peptidoglycan layer. |
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| Describe the GRAM NEGATIVE outer membrane. |
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| Outer membrane consists of LPS (lipopolysaccharide) |
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| Name the four genera of the family Micrococcaceae |
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| Micrococcus, Planococcus, Staphylococcus, Stomatococcus |
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| Family Micrococcaceae is typically catalase ______ and grows in _____ % NaCl |
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| POSITIVE, 5% |
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| What is the bridge between the peptidoglycan linkages? |
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| Pentaglycene. |
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| Micrococcus...cell arrangement and morphology. |
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| Gram positive cocci in tetrads and clusters. |
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| Micrococcus....aerobic or anaerobic? |
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| Aerobic |
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| Micrococcus....motile or non-motile? |
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| Non-motile |
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| Micrococcus...Catalase? |
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| POSITIVE |
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| Micrococcus...Oxidase??? |
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| POSITIVE |
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| Where is micrococcus found? |
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| In the environment and transient skin flora in humans and other animals. |
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| Name the 2 species of Micrococcus? |
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| M. luteus, M. lylae |
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| Planococcus....cell arrangement and morphology |
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| Gram positive cocci in pairs and tetrads |
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| Planococcus....aerobic or anaerobic? |
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| Aerobic |
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| Planococcus...motile or non-motile?? |
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| MOTILE COCCUS! All strains have 1-3 flagella |
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| Planococcus....Catalase? |
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| POSITIVE |
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| Corynebacterium....Gram stain andarangement |
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| Gram POSITIVE, straight or slightly curved, thin rods. They have "club ends". Chinese letter formations. |
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| Who described Corynebacterium strand in 1883? |
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| Klebs |
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| Who proved corynebacterium caused dipnhtheria? |
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| Loeffler (1884) |
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| First Nobel Prize in Medicine given to?? |
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| German doctor Von Bering for developing the anti-toxin to diphtheria. |
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| Corynebacterium genus are mostly catalase??? |
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| POSITIVE |
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| Corynebacterium genus are mostly...motile or nonmotile? |
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| Non-motile |
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| Corynebacterium genus cell walls contain what? |
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| mycolic acid, arabinose and galactose. |
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| Corynebacterium is found where? |
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| In nature, soil, water, on humans reside on the skin and mucous membranes. Nasopharynx, vagina and skin. |
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| A pseudomembrane forms in the airway with what bacterial infection? |
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| Corynebacterium diphtheriae |
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| Name some cell wall structures of Corynebacterium... |
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| Chemotype IV, Mycolic acids, Straight chain saturated, unsaturated fatty acids, Menaquinones, Vit K2 |
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| Four distinct colony (biotypes) types of Corynebacterium diphtheria are...? |
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| gravis, mitis, intermedius, belfanti. |
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| Corynebacterium biochemical and media reactions. |
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| PYR -, Phosphotase -, Esculin -, Urea -, produces acid from glucose and maltose (not sucrose, mannitol or xylose). |
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| Gravis shape? |
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| Short irregular rod, starch positive |
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| Mitis shape? |
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| long curved irregular rod, starch negative |
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| Intermidus shape? |
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| long rod, starch negative. |
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| Two tests for toxigenicty in ID of Corynebacterium? |
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| Schick test (in vivo) and Elek test (in vivo). |
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| Specialized transduction has two types. |
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| Lysogenic and lytic |
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| One molecule of toxin A can kill one eukaryotic cell in what bacteria? |
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| Corynebacterium diphtheria |
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| Most of the family Micrococcaceae are strict _________ (aerobes or anaerobes)?? |
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| AEROBES |
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| Planococci and Staphylococci belong to what phyletic line? |
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| Bacillus/Lactobacillus/Streptococcus |
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| Micrococci and Stomatococci belong to what phyletic line? |
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| Amycelial actinomycetes |
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| Staphylococci are in what phylum? |
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| Firmicutes |
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| Planococci are marine cocci that grow in ___% NaCL |
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| 15% |
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| Stomatococcus (part of the repiratory tract normal flora) is now a member of what genus? |
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| Rothia. So Stomatococcus mucilaginosus is no Rothia mucilaginsa. |
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| Planococcus...Oxidase??? |
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| POSITIVE |
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| Planococcus strains are capable of growth in up to ___% NaCl |
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| 15% |
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| Name 2 species of Planococcus |
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| P. citreus, and P. kocuri |
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| An encapsulated Grap positive coccus that is part of the normal human respiratory tract is genus.... |
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| Stomatococcus (Rothia). It is also associated with endocarditis. |
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| What is a non motile, weakly catalase + species of stomatococcus? |
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| S. mucilaginosus, currently known as R. mucilaginosa |
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| Staphylococcus....morphology and arrangement? |
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| Gram positive cocci in grape like clusters. |
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| Staphylococcus....aerobic or anaerobic? |
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| Facultatively anaerobic |
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| Staphylococcus...motile or nonmotile? |
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| Non motile |
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| Staphylococcus is catalase ____ and oxidase ___. |
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| Catalase positive, oxidase negative. |
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| Staphylococcus is salt tolerant to ___% |
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| 10% |
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| Staphylococcus hemolysis? |
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| Varies depending on species. |
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| Staphylococcus is genetically related to .... |
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| Enterococci, Streptococci, Lactobacilli, and Bacillus |
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| How many species of Staphylococcus are there and how many are associated with mucous membranes in humans and animals? |
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| 35 species, 17 associated with mucous membranes. |
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| Name some Staphylococcus species... |
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| S. capitis, S auricularis, and S. intermedius. |
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| What is the most important human pathogen? |
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| S. aureus |
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| Where is S. aureus found? |
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| In the external environment and anterior nares of 20-40% of adults. |
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| Differentiate between Micrococcus from Staphylococcus using what tests? |
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| Furazolidone disk, oxidase disk, bacitracin disk, lysostaphin, acid from glucose under anaerobic conditions. |
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| Staphylococcus is furazolidone....susceptible or resistant? |
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| Susceptible |
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| Staphylococcus is oxidase....? |
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| Negative |
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| Staphylococcus is bacitracin....susceptible or resistant? |
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| Resistant |
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| Staphylococcus is lysostaphin....susceptible or resistant? |
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| susceptible |
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| Does Staphylococcus produce acid from glucose under anaerobic conditions? |
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| Yes, Positive result |
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| Micrococcus is furazolidone....susceptible or resistant? |
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| Resistant |
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| Micrococcus is oxidase...? |
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| Positive |
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| Micrococcus is bacitracin....susceptible or resistant? |
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| Susceptible |
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| Micrococcus is lysostaphin....susceptible or resistant? |
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| resistant |
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| Does Micrococcus produce acid from glucose under anaerobic conditions? |
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| No, negative test results. |
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| There are two sources for genetic pathogenesis in S. aureus. What are they? |
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| Lysogenic conversion and chromosomal encoded virulence genes. |
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| Certain staphylococcal virulence genes are encoded by prophages.....what are they? |
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| Staphylokinase, PVL, enterotoxin, and exofoliatin. |
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| Some chromosomal encoded virulence genes (for staphylococcus) include... |
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| hemolysins, proteases, Protein A, clumping factor, capsule production and nucleases. |
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| What determines the pathogenicity of S. aureus? |
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| Cellular antigens, like capsules, polysaccharide A, Protein A, Clumping factor, and adhesions. |
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| What helps prevent ingestion of a microbe by polymorphonuclear cells? |
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| A capsule |
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| What are the most common polysaccharide capsules of Staph? |
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| 5 and 8. Both are antiphagocytic |
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| What contains linear ribitol teichoic acids and functions in adherence of gram positive bacteria to mucosal surfaces? |
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| Polysaccharide A |
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| S. aureus cell walls have a unique protein that binds the Fc region of host IgG molecules, what is this protein called? |
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| Protein A |
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| How does Protein A work in S. aureus? |
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| The protein interferes with host immune system, specifically by interfering with opsonization and ingestion of bacteria by polymorphonuclear cells. |
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| What substance forms the basis for the coagglutination test in the lab? |
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| Protein A |
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| Protein A is ____ daltons and is immunogenic. |
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| 42,000 |
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| What is clumping factor (S. aureus)? |
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| Bound or surface material that is able to bind fibrinogen and fibrin. This helps S. aureus to attach to surfaces. |
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| What are adhesions? |
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| Surface proteins that enable the bacterium to bind to proteins such as collagen. These are covalently incorporated into the structure of the peptidoglycan. |
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| What is in some strains of S. aureus that allows it to form biofilms on cardiac or other implanted devices which gives humans a greater risk of developing infections? |
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| Single-nucleotide polymorphisms (SNPs) |
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| SNPs produce ________ _______ _________ _, which adheres to host _________ and adheres to implants. (In S. aureus) |
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| Fibronectin binding Protein A (FnBPA), FIBRONECTIN. |
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| A single amino acid substitution within the FnBPA can do what? |
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| affect virulence. |
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| Lysostaphin is what? |
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| An endopeptidase that cleaves the pentaglycene bridge. |
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| What are the determinants of S. aureus pathogenicity? |
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| Extracellular proteins, like catalase, coagulase (free, not bound), hydrolyases, staphylokinase (fibrolysin), Beta lactamase enzyme, pyrogenic exotoxins, other exotoxins (like PVL and epidermolytic toxin) |
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| What is the function of catalase in S. aureus? |
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| This enzyme inactivates hydrogen peroxide and free radicals formed by the myeloperoxidase system in phagocytic cells after ingestion of microbes. |
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| What are the cultural filtrates that act to coat the bacteria with fibrin, rendering them resistant to phagocytosis. |
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| Free Coagulase. |
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| What does free coagulase do? |
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| Converts fibrinogen to fibrin during abscess formation, becomes the walls of the abscess. |
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| What are 4 different hydrolylases? |
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| Lipases, phospholipase C, hyaluronidase, and themonuclease. |
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| The hydrolylase that helps the spread of the organism in cutaneous and subcutaneous tissues is....? |
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| Lipase |
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| The hydrolylase that impacts tissues and makes them more susceptible to damage from components of the complement system? |
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| Phospholipase C |
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| The hydrolylase that hydrolyzes the intercellular matrix of mucopolysaccharides thus allowing the organism to spread? |
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| Hyaluronidase |
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| The hydrolylase that cleaves host DNA and RNA? |
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| Thermonuclease |
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| Also known as fibrinolysin, this extracellular protein is produced by several strains of S. aureus and dissolves fibrin clots (which contributes to the spread of the organism). |
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| Staphylokinase |
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| Where do the genes for the Beta lactamase enzyme usually reside? |
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| On plasmids. |
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| How can resistance genes (Beta lactamase) be transferred from one bacteria to another? |
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| Either through transduction or transformation. |
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| Over ___% of all S. aureus microbes produce one form of the Beta lactamase enzyme. |
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| 80% |
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| What is the toxin that is a superantigen and was first seen in patients in 1981? How many daltons is it? |
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| Toxic shock syndrom toxin 1 (TSST-1). 22,000 Daltons. |
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| TSST-1 is what type of exotoxins? |
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| Pyrogenic exotoxin. It stimulates the proliferation of T cells. |
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| Heat stable molecules responsible for the clinical picture of food poisoning is.... |
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| Enterotoxins |
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| What are the enterotoxins responsible for Staph food poisoning? |
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| Enterotoxin A-E, H, and I |
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| What is genus microbe is responsible for the most common form of food poisoning in the US? |
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| Staphylococcus. |
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| What two hemolysins does S. aureus produce? |
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| Beta hemolysin and delta hemolysin. |
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| What is a sphingomyelinase (35,000 daltons) that requires Mg++ for activity and attacks the sphingomyelin content in cell membranes? |
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| Beta hemolysin |
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| What acts as a surfactant and disrupts the cell membrane to cause channels and results in leakage of cellular components? |
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| delta hemolysin |
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| What exotoxin has a direct effect on human PMN cell membranes and causes cell swelling and lysis? |
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| LPV (leucocidin, Panton-Valentine) |
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| What exotoxin is made of 2 proteins (each 24,000 daltons), ET-A heat stable and ET-B not heat stable, one chromosomally encoded, the other plasmid encoded? |
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| Exofoliations or epidermolytic toxins. |
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| Staphylococcal scalded skin syndrome is caused by what exotoxin? How does it work? |
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| Exofoliations or epidermolytic toxins. Proteolytic action dissolves the mucopolysaccharide matrix of the epidermis. |
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| What kind of diseases can S. aureus cause? |
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| abscesses, endocarditis, osteomyelitis, food poisoning, and TSS. |
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| What microbe is an infrequent cause of UTI's? |
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| Staphylococcus saprophyticus |
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| What causes furuncles? |
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| S. aureus |
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| What causes carbuncles? |
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| S. aureus |
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| What causes impetigo? |
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| S. aureus |
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| What can cause scalded skin syndrome also called Lyells disease? |
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| S. aureus |
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| S. aureus causes TSS (toxic shock syndrome) in what part of the body? |
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| The female genital tract. |
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| How is it that S. aureus is resistant to penicillin? |
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| Beta lactamase genes cleave the Beta lactam ring of penicillin |
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| What is MRSA? |
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| Methicillin resistant staph aureus |
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| What is VISA? |
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| Vancomycin intermediate-resistant Staph aureus |
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| How is Streptococci, Enterococci, and Streptococci-like bacteria classified? |
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| Based on molecular methods, DNA-DNA hybridizations, and 16s rRNA sequencing. |
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| What genera of Order _____________ are described by their ability to utilize glucose. |
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| Lactobacillales |
