Relationships Between Bacteria and Clinical Features of Disease 4-c The Bacteria And various pages in additional chapters Relationships Between Bacteria and Clinical Features of Disease

Many of the differences account for disease pathogenesis Structure/Function Relationships Differences exist between human (eukaryotic) and bacterial (prokaryotic) cells Many of the differences account for disease pathogenesis And, allow exploitation of the differences to develop chemotherapy (antibiotics)

Differences Accounting for Pathogenesis Structure Pathogenesis Capsule K-antigen All pathogens that cause pneumonia & meningitis have capsules Haemophilus influenzae, Neisseria meningitidis, Escherichia coli, Streptococcus pneumoniae, Klebsiella pneumoniae, group B streptococci Plasmids Antibiotic resistance (R-factor) Outer membrane (Gram negative) Endotoxin (Lipid A) O-antigens Flagella H antigen, virulence factor Attachment to cells Fimbriae Pili Spread of AB resistance genes

Poisonous substances produced by microbes Toxins Poisonous substances produced by microbes Transported in blood Produce fever, cardiovascular disturbances, diarrhea, shock Inhibit protein synthesis, destroy blood cells & vessels, disrupt nervous system

Two Types Exotoxin Endotoxin Gram positive Gram negative Product of cell Part of LPS Protein Lipid portion (Lipid A) Affects cell functions Fever, weakness, aches, shock High toxicity Low toxicity Lethal dose small Lethal dose larger Gas gangrene, tetanus, botulism, scarlet fever Typhoid fever, UTI, meningococcal meningitis

Alcaligenes faecalis Azotobacter Bacillus Bacillus anthracis Bacillus cereus Bacillus megaterium Bacillus subtilis Borrelia burgdorferi Clostridium Clostridium botulinum Clostridium perfringens Clostridium sporogenes Clostridium tetani Corynebacterium diphtheria Corynebacterium xerosis Enterobacter Enterobacter aerogenes Enterobacter sakazaki Enterobacteriaceae Escherichia Escherichia coli Gram negative Gram positive Klebsiella Klebsiella pneumonia Lactobacillus plantarum Micrococcus luteus Mycobacteria Mycobacterium leprae Mycobacterium smegmatis Mycobacterium tuberculosis Neisseria gonorrhoea Nocardia Proteus Proteus vulgaris Pseudomonas aeruginosa Salmonella Salmonella typhimurium Serratia marcescens Shigella dysenteriae Spirillum Staphylococcus Staphylococcus aureus Staphylococcus epidermidis Streptococcus Streptococci mutans Streptococci pneumoniae Streptococcus viridans Treponema pallidum Vibrio cholera

Alcaligenes faecalis Azotobacter Bacillus Bacillus anthracis Bacillus cereus Bacillus megaterium Bacillus subtilis Borrelia burgdorferi Clostridium Clostridium botulinum Clostridium perfringens Clostridium sporogenes Clostridium tetani Corynebacterium diphtheria Corynebacterium xerosis Enterobacter Enterobacter aerogenes Enterobacter sakazaki Enterobacteriaceae Escherichia Escherichia coli Gram negative Gram positive Klebsiella Klebsiella pneumonia Lactobacillus plantarum Micrococcus luteus Mycobacteria Mycobacterium leprae Mycobacterium smegmatis Mycobacterium tuberculosis Neisseria gonorrhoea Nocardia Proteus Proteus vulgaris Pseudomonas aeruginosa Salmonella Salmonella typhimurium Serratia marcescens Shigella dysenteriae Spirillum Staphylococcus Staphylococcus aureus Staphylococcus epidermidis Streptococcus Streptococci mutans Streptococci pneumoniae Streptococcus viridans Treponema pallidum Vibrio cholera

Bacilli, rods Cocci Curved Spirochete Bacillus anthracis Neisseria gonorrhoea Clostridium botulinum Staphylococcus aureus Clostridium perfringens Streptococci mutans Clostridium tetani Streptococci pneumoniae Corynebacterium diphtheria Curved Escherichia coli Vibrio cholera Klebsiella pneumonia Spirochete Mycobacterium leprae Borrelia burgdorferi Mycobacterium tuberculosis Treponema pallidum

Clinically Significant Bacteria Arrangement: rods, bacilli Bacillus Clostridium Corynebacterium Escherichia coli Mycobacterium

Bacillus anthracis Gram positive, rods Spore forming Aerobe or facultative Found in soil Disease: Fig. 11.17b Bacillus germinating Anthrax Pulmonary Cutaneous GI Biological warfare Ch 23, p 680-1 Ch / Pg 3 / 71 4 / 96-97 11 / 331 23 / 679-681, 702 LM / 18-9

Contact with material containing anthrax endospores Cutaneous Anthrax Contact with material containing anthrax endospores Results in skin lesion covered by a black scab Diagnosis New blood test detection Fig. 4.21 Endospore Fig. 23.7 Anthrax lesion

Clostridium Gram positive, rods Obligate anaerobe Endospores Widely found in soil, GI tracts human, animals Toxins (neuro) Diseases: Fig. 23.8 gangrene Botulism Tetanus Gas gangrene Food borne diarrhea Ch / Pg 11 / 330 23 / 681-2, 702 15 / 459-464 LM / 18-20

Wound is seriously necrotic Gas Gangrene C. perfringens If wound is brand new Prompt cleaning of serious wounds Antibiotic treatment (penicillin) Wound is seriously necrotic Surgery, amputation Fig. 23.9 Hyperbaric chamber

Corynebacterium diphtheriae Gram positive Club-shaped, pleomorphic Aerobic or (facultative anaerobic) Non-spore forming Toxin (cyto) Metachromatic granules Volutin Fig. 24.5 Corynebacterium Disease: Ch / Pg Diphtheria 11 / 335 24 / 715-6, 718 LM / 24-25

Airborne transmission Forms a leathery, grayish membrane in the throat Diphtheria Airborne transmission Forms a leathery, grayish membrane in the throat Sore throat, fever, general malaise, swelling of neck Diagnosis: Selective & differential media Fig. 24.6 Diphtheria membrane Part of the DPT immunizations for children

Escherichia coli Gram negative, rods Facultative anaerobe Toxins Invasive Hemorrhagic Plasmid borne Diseases: Fig. 4.11 E. coli Foodborne epidemics Urinary tract infections (‘travelers diarrhea’) Gastroenteritis E. coli O157:H7 Ch / Pg 4 / 83 11 / 323 25 / 758-9

Gastroenteritis E. coli (EHEC) Hemorrhagic colitis (very bloody stools) Adhere to intestinal mucosa, destroy microvilli Serotype: O157:H7 Infective dose 100 bacteria Diagnosis: rapid methods Fig. 24.6 Enterohemorrhagic E. coli

Mycobacterium Acid fast, slender rod Obligate aerobe Non-spore forming Disease: Tuberculosis Leprosy (Hanson’s Disease) Fig. 24.9 Mycobacterium Ch / Pg 3 / 70-1 11 / 334-5 22 / 651-2, 665 24 / 719-723 LM / 21-22 Mycobacterium tuberculosis M. leprae

Tuberculosis Inhale the bacillus Diagnosis: Lodge in the lung alveoli Can progress to a lung damaging inflammation Diagnosis: TB skin test Sputum smears Chest X ray, CT Fig. 24.2 Lower Respiratory System Fig. 24.11 TB skin test

Invades myelin sheath, peripheral nervous system Leprosy Invades myelin sheath, peripheral nervous system Cause nerve damage 12 day generation time Never grown in culture Necrosis of tissue Diagnosis: Detect acid-fast rods in patient fluids Lepromin test Fig. 22.9 Leprosy Also called Hansen’s disease

Clinically Significant Bacteria Arrangement: cocci Neisseria gonorrhoea Staphylococcus aureus Streptococci

Neisseria gonorrhoea Gram negative Diplococcus Obligate aerobe Non-spore forming Disease: STD: Gonorrhea Meningitis Fig. 22.4 Neisseria meningitis, pharynx Ch / Pg 22 / 645-6 26 / 790-793

Leucocytes move to infected area Gonorrhea Attaches via fimbriae Leads to inflammation Leucocytes move to infected area Characteristic pus forms In women, only the cervix is infected Diagnosis: Stained pus smears Fig. 26.7 A smear of pus, patient with gonorrhea

Staphylococcus aureus Gram positive, cocci Grape-like clusters Facultative anaerobe Toxin Fig. 11.18 Staphylococcus aureus Diseases (many): Surgical wounds (nosocomial) TSS (toxic shock syndrome) Skin infections (impetigo, scalded skin) Endocarditis Ch / Pg 11 / 332 21 / 615-20, 633 23 / 674-5 25 / 751

Acute Bacterial Endocarditis Gain access to bloodstream Leads to infection Forms fibrin-platelet vegetations Rapid destruction of heart valves within the endocardium Diagnosis: Echocardiogram Fig. 23.4 Bacterial endocarditis

Clinical Ramifications, 2 types S. aureus and S. epidermidis can be divided into 2 groups Slime layer allows S. epidermidis to colonize catheters Fig. 21.3a, b. Coagulase negative staphylococci Staphylococcus aureus Staphylococcus epidermidis Coagulase positive Coagulase negative Produces enterotoxins Produces slime layer Damage tissue Adhere to surfaces

Streptococcus Gram positive, cocci, chains Facultative anaerobe alpha, beta, gamma hemolytic Secrete toxins Diseases (many): Pneumonia Strep throat Scarlet fever Skin infections Rheumatic fever Fig. 11.19 Streptococcus Ch / Pg 11 / 333 14 / 427 21 / 620-1 23 / 674-6 25 / 751

Skin Infection - Erysipelas Most important b-hemolytic species S. pyogenes Reddish patches on skin - dermal layer Tissue destruction Pus generated Enter bloodstream cause sepsis Fig. 21.6 Lesion of erysipelas

Q’s What is seen at the ends of the cells of Clostridium tetani in this micrograph? Very thick flagella Endospores The cells are undergoing division These cells are pleomorphic, accounting for this shaped cell Budding cells

Which of these is NOT correctly matched? Q’s Which of these is NOT correctly matched? Escherichia coli – gastroenteritis Staphylococcus aureus – TSS Clostridia tetani – gangrene Bacillus anthracis – anthrax Which of following is not true about fimbriae? They are composed of protein They may be used for attachment They are composed of pilin They may be used for motility They are found on Gram negative cells

Q’s The formation of a tough grayish membrane in the throat is characteristic of: Tuberculosis Scarlet fever Diphtheria Streptococcal pharyngitis A positive tuberculin skin test indicates that an individual: Has an active case of tuberculosis May have been vaccinated with BCG Has immunity to TB due to an earlier infection Any of the above is possible

Which of these is an infection of the lower respiratory tract: Q’s Which of these is an infection of the lower respiratory tract: Botulism Diphtheria Tuberculosis Streptococcal pharyngitis An acid-fast stain of a patient’s sputum reveals acid-fast rods. This indicates infection with: Staphylococcus aureus Mycobacterium tuberculosis Corynebacterium diphtheria Any of the above is possible

Which of these diseases is also known as Hanson’s disease: Q’s Which of these diseases is also known as Hanson’s disease: Botulism Leprosy Tuberculosis Gangrene Anthrax Staphylococcus aureus is responsible for all of the following except: Acne Impetigo Toxic shock syndrome Scalded skin syndrome

The diagram shows the structure of a: Q’s The diagram shows the structure of a: Gram-negative cell wall Gram-positive cell wall Eukaryotic cell wall

Q’s The antibiotic Gentamicin binds the 30S ribosome subunit. This will interfere with: Protein synthesis in eukaryotic cells Protein synthesis in prokaryotic cells Cell division in eukaryotic cells Cell division in prokaryotic cells

Q’s Disease Bacteria 1. Bacillus 2. Streptococcus 3. Klebsiella Leprosy Diphtheria Anthrax Strep throat Botulism Hemorrhagic colitis Pneumonia Scarlet fever Skin infections Tetanus Meningitis Tuberculosis Acute endocarditis Food borne diarrhea Gas gangrene UTI 1. Bacillus 2. Streptococcus 3. Klebsiella 4. Escherichia 5. Neisseria 6. Staphylococcus 7. Mycobacterium 8. Clostridium 9. Corynebacterium 1. C 2. G, H, I 3. g 4. N, P, F 5. K 6. I, M 7. L, A 8. E, J, O, N 9. b