PHC 454 Pharmaceutical Microbiology and Parasitology PDF

PHC 454 Pharmaceutical Microbilogy and Parasitology The Gram-Negative Bacilli of Medical Importance Copyright © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill...

PHC 454 Pharmaceutical Microbilogy and Parasitology The Gram-Negative Bacilli of Medical Importance Copyright © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 1  Learning Outcome 1: to understand and explain the morphology and pathogenesis of pathogenic bacteria 2: evaluate the consequences of infection, treatment and control of selected pathogenic bacteria 2 Copyright © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. Aerobic Gram-Negative Nonenteric Bacilli Large, diverse group of non-spore-forming bacteria Wide range of habitats – large intestines (enteric), zoonotic, respiratory, soil, water Most are not medically important; some are true pathogens, some are opportunists All have outer membrane lipopolysaccharide of the cell wall – endotoxin 3 Copyright © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education.  4 Copyright © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education.  Aerobic Gram-Negative Nonenteric Bacilli Pseudomonas and Burkholderia – opportunistic pathogens Brucella and Francisella – zoonotic pathogens Bordetella and Legionella – mainly human pathogens 5 Copyright © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. Pseudomonas: The Pseudomonads Small gram-negative rods with a single polar flagellum Free living – Primarily in soil, sea water, and fresh water; also colonize plants and animals Important decomposers and bioremediators Frequent contaminants in homes and clinical settings Use aerobic respiration; do not ferment carbohydrates Produce oxidase and catalase Many produce water soluble pigments 6 Copyright © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education.  Pseudomonas aeruginosa Copyright © McGraw-Hill Education. Permission required for reproduction or display. Common inhabitant of soil and water Intestinal resident in 10% normal people Resistant to soaps, dyes, quaternary ammonium © Science VU/Visuals Unlimited disinfectants, drugs, drying Frequent contaminant of ventilators, IV solutions, anesthesia equipment Opportunistic pathogen © Bottone E.J. and Perez A.A., II, The Mount Sinai Hospital New York 7 Copyright © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education.  Pseudomonas aeruginosa Common cause of nosocomial infections in hosts with burns, neoplastic disease, cystic fibrosis Complications include pneumonia, UTI, abscesses, otitis, and corneal disease Endocarditis, meningitis, bronchopneumonia Grapelike odor and greenish-blue pigment (pyocyanin) Multidrug resistant 8 Copyright © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education.  Related Gram-Negative Aerobic Rods Genera Burkholderia, Acinetobacter, Stenotrophomonas Similar to pseudomonads Wide variety of habitats in soil, water, and related environments Obligate aerobes; do not ferment sugars Motile, oxidase positive Opportunistic 9 Copyright © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education.  Burkholderia Burkholderia cepacia – active in biodegradation of a variety of substances; opportunistic agent in respiratory tract, urinary tract, and occasionally skin infections; drug resistant B. pseudomallei – generally acquired through penetrating injury or inhalation from environmental reservoir; wound infections, bronchitis and pneumonia, septicemia 10 Copyright © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education.  Acinetobacter and Stenotrophomonas Acinetobacter baumanii – nosocomial and community acquired infections; wounds, lungs, urinary tract, burns, blood; extremely resistant – treatment with combination antimicrobials Stenotrophomonas maltophilia – forms biofilms; contaminant of disinfectants dialysis equipment, respiratory equipment, water dispensers, and catheters; clinical isolate in respiratory soft tissue, blood, CSF; high resistance to multidrugs 11 Copyright © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education.  Concept Check: The main reservoir for Pseudomonas aeruginosa is A. Soil and Water B. Infected Individuals C. Asymptomatic Carriers D. Wild Animals 12 Copyright © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education.  Brucella and Brucellosis Tiny gram-negative coccobacilli 2 species: – Brucella abortus (cattle) – Brucella suis (pigs) Brucellosis, malta fever, undulant fever, and Bang disease – a zoonosis transmitted to humans from infected animals Fluctuating pattern of fever – weeks to a year Combination of tetracycline and rifampin or streptomycin Animal vaccine available Potential bioweapon 13 Copyright © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education.  Agglutination Titer Test for Brucellosis Copyright © McGraw-Hill Education. Permission required for reproduction or display. Antibody(+) Antibody(–) 1 2 3 4 5 6 for Brucella for Brucella 1:10 Antigen 1:20 1:40 1:80 1:160 Brucella POSITIVE NEGATIVE cells 1:320 REACTION REACTION 1:640 1:1280 Picture courtesy of Vircell (a) Serum containing (b) Serum lacking (c) The numbered lanes are antibodies specific to specific Brucella individual serum samples. Brucella captures the antibodies does not The serum titer can be determined test cells (antigen) and react, and antigens by diluting it through wells A to H, disperses the reaction pellet into well then looking for the last well in a through the well. bottom. series with a positive reaction. The titer is the dilution of that well. 14 Copyright © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. Francisella tularensis and Tularemia Causes tularemia, a zoonotic disease of mammals endemic to the northern hemisphere, particularly rabbits Transmitted by contact with infected animals, water and dust or bites by vectors Headache, backache, fever, chills, malaise, and weakness 10% death rate in systemic and pulmonic forms Intracellular persistence can lead to relapse Gentamicin or tetracycline Attenuated vaccine Potential bioterrorism agent 15 Copyright © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education.  Bordetella pertussis Minute, encapsulated coccobacillus Causes pertussis or whooping cough, a communicable childhood affliction Acute respiratory syndrome Often severe, life-threatening complications in babies Reservoir – apparently healthy carriers Transmission by direct contact or inhalation of aerosols Copyright © McGraw-Hill Education. Permission required for reproduction or display. 16 CDC Copyright © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education.  Bordetella pertussis Virulence factors – Receptors that recognize and bind to ciliated respiratory epithelial cells – Toxins that destroy and dislodge ciliated cells Loss of ciliary mechanism leads to buildup of mucus and blockage of the airways Vaccine – DTaP – acellular vaccine contains toxoid and other Ags 17 Copyright © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education.  Alcaligenes Live primarily in soil and water May become normal flora A. faecalis – most common clinical species – Isolated from feces, sputum, and urine – Occasionally associated with opportunistic infections – pneumonia, septicemia, and meningitis 18 Copyright © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education.  Legionella pneumophila and Legionellosis Widely distributed in water Live in close association with amoebas Copyright © McGraw-Hill Education. Permission required for reproduction or display. Legionella bacteria CDC CDC 19 (a) (b) Amoeba cell Copyright © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education.  Legionella pneumophila and Legionellosis 1976 epidemic of pneumonia afflicted 200 American Legion members attending a convention in Philadelphia and killed 29 Legionnaires disease and Pontiac fever Prevalent in males over 50 Nosocomial disease in elderly patients Fever, cough, diarrhea, abdominal pain, pneumonia fatality rate of 3-30% Azithromycin 20 Copyright © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education.  Enterobacteriaceae Family Enterics Large family of small, non-spore-forming gram- negative rods Many members inhabit soil, water, decaying matter, and are common occupants of large bowel of animals including humans Most frequent cause of diarrhea through enterotoxins Enterics, along with Pseudomonas sp., account for almost 50% of nosocomial infections 21 Copyright © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education.  Enterobacteriaceae Family Facultative anaerobes, Copyright © McGraw-Hill Education. Permission required for reproduction or display. grow best in air Lactose (+) Lactose (–) All ferment glucose, Lactose (–) reduce nitrates to nitrites, Lactose (+) H2S (+) Lactose (–) oxidase negative, and catalase positive Divided into coliforms (lactose fermenters) and non-coliforms (non- lactose fermenters) Enrichment, selective and differential media utilized © Kathy Park Talaro © Kathy Park Talaro for screening samples for (a) (b) pathogens 22 Copyright © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education.  The Enteric Genera Copyright © McGraw-Hill Education. Permission required for reproduction or display. Colonies from selective media inoculated into triple-sugar iron (TSI) Rapid lactose fermentation on (TSI) + Lactose Lactose – + Glucose Glucose + Motility Phenylalanine (PA) + – + – Indole Voges-Proskauer H2S Citrate + – + (VP) – + – + – Klebsiella Moellerella Proteus H2S + – Citrate Motility + – + – Providencia Morganella ONPG Erwinia – VP+Enterobacter + – Citrobacter – VP- Citrobacter Hafnia Edwardsiella Citrate Urease + – + – Escherichia See table 20.2 for a brief discussion Yersinia Shigella LDC ONPG of each differential test + – gelatinase + – Kluyvera Citrobacter Serratia Salmonella 23 Copyright © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education.  BBL Enterotube II, Rapid Biochemical Testing of Enterics 24 Copyright © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education.  Antigenic Structures and Virulence Factors Complex surface antigens contribute to pathogenicity and trigger immune response: H – flagellar Ag Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. K – capsule and/or fimbrial Capsule (K antigen, or Ag Vi in Salmonella O – somatic or cell wall Ag – all Somatic (O antigen, or cell wall antigen) have Endotoxin Flagellar (H antigen) Exotoxins 25 Copyright © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education.  Concept Check: Which of the following is true of the enterics? A. Some are normal flora B. Some release endotoxin C. Some release enterotoxins D. All of the above are true 26 Copyright © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education.  Escherichia coli: The Most Prevalent Enteric Bacillus Most common aerobic and non-fastidious bacterium in gut 150 strains Some have developed virulence through plasmid transfer, others are opportunists 27 Copyright © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education.  Pathogenic Strains of E. coli Enterotoxigenic E. coli causes severe diarrhea due to heat-labile toxin and heat-stable toxin – stimulate secretion and fluid loss; also has fimbriae Enteroinvasive E. coli causes inflammatory disease of the large intestine Enteropathogenic E. coli linked to wasting form infantile diarrhea Enterohemorrhagic E. coli, O157:H7 strain, causes hemorrhagic syndrome and kidney damage 28 Copyright © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education.  Escherichia coli Pathogenic strains frequent agents of infantile diarrhea – greatest cause of mortality among babies Causes ~70% of traveler’s diarrhea Causes 50-80% UTI Coliform count – indicator of fecal contamination in water 29 Copyright © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education.  Opportunistic Coliforms Klebsiella pneumoniae – normal inhabitant of respiratory tract, has large capsule, cause of nosocomial pneumonia, meningitis, bacteremia, wound infections, and UTIs 30 Copyright © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education.  Opportunistic Coliforms Enterobacter sp. – UTIs, surgical wounds Citrobacter sp. – opportunistic UTIs and bacteremia Serratia marcescens – produces a red pigment; causes pneumonia, burn and wound infections, septicemia and meningitis Copyright © McGraw-Hill Education. Permission required for reproduction or display. 31 © Kathy Park Talaro © Kathy Park Talaro Copyright © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education.  Noncoliform Lactose-Negative Enterics Proteus, Morganella, Providencia Salmonella and Shigella 32 Copyright © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. Opportunists: Proteus and Its Relatives Ordinarily harmless saprobes in soil, manure, sewage, polluted water, commensals of humans and animals – Proteus sp. – swarm on surface of moist agar in a concentric pattern and are involved in UTI, wound infections, pneumonia, septicemia, and infant diarrhea – Morganella morganii and Providencia sp. involved in similar infections 33 Copyright © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education.  Salmonella and Shigella Well-developed virulence factors, primary pathogens, not normal human flora Salmonelloses and Shigelloses – Some gastrointestinal involvement and diarrhea but often affect other systems – Homework : please read Tortora textbook page of 740 & 741 Copyright © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. Typhoid Fever and Other Salmonelloses Salmonella typhi – most serious pathogen of the genus; cause of typhoid fever; human host S. cholerae-suis – zoonosis of swine S. enteritidis – includes 1,700 different serotypes based on variation on O, H, and Vi Flagellated; survive outside the host Resistant to chemicals – bile and dyes 35 Copyright © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education.  36 Copyright © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education.  Typhoid Fever Copyright © McGraw-Hill Education. Permission required for reproduction or display. Bacillus enters with ingestion of (a) Typhoid bacilli fecally contaminated food or water; occasionally spread by close personal contact Intestinal Asymptomatic carriers; some Villi x500 chronic carriers shed bacilli from gallbladder (b) Blood vessels Bacilli adhere to small Carried to liver, spleen Intestinal wall intestine, cause invasive diarrhea that leads to septicemia Treat with chloramphenicol or Ulcers (c) Perforations sulfatrimethoprim 2 vaccines for temporary protection (d) CDC 37 Copyright © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education.  Animal Salmonelloses Salmonelloses other than typhoid fever are called enteric fevers, Salmonella food poisoning, and gastroenteritis Usually less severe than typhoid fever but more prevalent Caused by one of many serotypes of Salmonella enteritidis; all zoonotic in origin but humans can become carriers – Cattle, poultry, rodents, reptiles, animal, and dairy products – Fomites contaminated with animal intestinal flora 38 Copyright © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education.  Shigella and Bacillary Dysentery Shigellosis – incapacitating dysentery S. dysenteriae, S. sonnei, S. flexneri, and S. boydii Human parasites Invades villus of large intestine, does not perforate intestine or invade blood Enters Peyer’s patches instigate inflammatory response; endotoxin and exotoxins Treatment – fluid replacement and ciprofloxacin and sulfatrimethoprim Copyright © McGraw-Hill Education. Permission required for reproduction or display. 39 (a) CDC (b) Copyright © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education.  The Enteric Yersinia Pathogens Yersinia enterocolitica – domestic and wild animals, fish, fruits, vegetables, and water – Bacteria enter small intestinal mucosa, some enter lymphatic and survive in phagocytes; inflammation of ileum can mimic appendicitis Y. pseudotuberculosis – infection similar to Y. enterocolitica, more lymph node inflammation 40 Copyright © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. Nonenteric Yersinia pestis and Plague Nonenteric Copyright © McGraw-Hill Education. Permission required for reproduction or display. Tiny, gram-negative rod, unusual bipolar staining and capsules Virulence factors – capsular and envelope proteins protect against phagocytosis and foster intracellular growth CDC – Coagulase – Endotoxin – Murine toxin 41 Copyright © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education.  Yersinia pestis Humans develop plague through contact with wild animals (sylvatic plague) or domestic or semidomestic animals (urban plague) or infected humans Found in 200 species of mammals – rodents, without causing disease Flea vectors – bacteria replicates in gut, coagulase causes blood clotting that blocks the esophagus; flea becomes ravenous 42 Copyright © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education.  Infection Cycle of Yersinia pestis Copyright © McGraw-Hill Education. Permission required for reproduction or display. Aerosol Droplets Chipmunk Flea Flea Ground squirrel Mouse Flea Bubonic Pneumonic plague plague Endemic reservoir hosts Amplifying hosts Human (accidental) hosts: Human-to-human transmission is less common 43 Copyright © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education.  Pathology of Plague ID 3-50 bacilli Bubonic – bacillus multiplies in flea bite, enters lymph, causes necrosis and swelling called a bubo in groin or axilla Septicemic – progression to massive bacterial growth; virulence factors cause intravascular coagulation subcutaneous hemorrhage and purpura – black plague Pneumonic – infection localized to lungs, highly contagious; fatal without treatment 44 Copyright © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education.  Diagnosis, Treatment and Prevention of Plague Diagnosis depends on history, symptoms, and lab findings from aspiration of buboes Treatment: streptomycin, tetracycline, or chloramphenicol Killed or attenuated vaccine available Prevention by quarantine and control of rodent population in human habitats 45 Copyright © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education.  Oxidase-Positive Nonenteric Pathogens Pasteurella multocida Haemophilus influenzae H. aegyptius H. ducreyi H. parainfluenzae H. aphrophilus 46 Copyright © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education.  Pasteurella multocida Zoonotic genus; normal flora in animals Opportunistic infections Animal bites or scratches cause local abscess that can spread to joints, bones, and lymph nodes Immunocompromised are at risk for septicemia and complications Treatment: penicillin and tetracycline 47 Copyright © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education.  Haemophilus Tiny gram-negative pleomorphic rods Fastidious, sensitive to drying, temperature extremes, and disinfectants None can grow on blood agar without special techniques – chocolate agar Require hemin, NAD, or NADP Some species are normal colonists of upper respiratory tract or vagina (H. parainfluenzae, H. ducreyi) Others are virulent species responsible for childhood meningitis, and chancroid 48 Copyright © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education.  Haemophilus H. influenzae – acute bacterial meningitis, epiglottitis, otitis media, sinusitis, pneumonia, and bronchitis – Subunit vaccine Hib Copyright © McGraw-Hill Education. Permission required for reproduction or display. CDC 49 Copyright © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education.  Haemophilus H. aegyptius – conjunctivitis, pink eye Copyright © McGraw-Hill Education. Permission required for reproduction or display. Reprinted from Farrar and Lambert, Pocket Guide for Nurses: Infectious Diseases, © 1984, Williams and Wilkins, Baltimore, MD. Photo by Dr. M. Tapert H. ducreyi – chancroid STD H. parainfluenzae and H. aphrophilus – normal oral and nasopharyngeal flora; infective endocarditis 50 Copyright © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education.  51 Copyright © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education.