Gram negative cocci. Contains one family. Neisseriaceae and 15 genera. Common Neisseria Species N. gonorrhoeae. N. meenigitidis. N. sicca. N. mucosa. Pus forming. Diplococci. Coffee bean shaped.
Neisseria gonorrhoeae virulent factors
Gonococci. Opa (opacity) proteins attachment to host cell. Bind human transferrin (lactoferrin) will bind to host and steal iron. IgA protease enzyme that destroy proteins. Lipooligosaccharide (LOS) Gram negative covering Main factor for damage. Por (porin protein OM) allows intracellular survival. Pili (intial attachment to host cell). Betalactamase
Pathogenesis of Neisseria gonorrhoeae
"The pilli allow attachment to microvillus and is taken in via endocytosis. Transmission is through sexual transmission. Enter into host cells and can be taken in by macrophages but can survive inside cells. Main attachment is in cervix cells
Clinical Disease of Gonorrhea
Sexally transmitted. Asymptomatic carriage is major reservoir. Complications in femalse of 10-20 percent. Is under reported. Presents differently between male and females. Can be transmitted to the throat via oral sexual contact. Direct or indirect contact with sexual organs.
Females and gonorrhea
High right after single exposure. Can be asymptomatic infections frequently not diagnosed. MAJOR RESERVOIR IS ASYMPTOMATIC. Vaginal discharge 7 to 21 days after exposure. Can lead to PID chronic infection can lead to sterility. Can be transmitted to infant at delivery (silver nitrate).
Males and gonorrhea
Painful burning urination. Yellow and green discharge. Have acute disese with obvious systoms. Rare complications.
Spread or disperse septicemia. skin. and joint infections.
Measure of True Positive Rate. No of true positives/No. of actual positives. No of true positives/no of (true postivies + false negatives)
Meaure of true negative rates. No of true negatives/No of actual negatives
Diagnosis of N. gonorrhea
Gram stain of discharge that shows gram negative diplococcus with a coffee bean shape. Can also use chocolate media to grow N. gonorrhea. It is a media with lysed red blood cells. Can also use a muller hinton agar mixed with chocolate agar along with antibiotics to help isolate N. gonorrhoeae
Treatment of N. gonorrhoeae
N. gonorrhoeae natural competence changes antigenic composition (naturally transformable). Is diploid has two sets of chromosomes. Most strains now resistant to penicillin. so use ciprofloxacin. CDC recommends ceftriaxone. No effect vaccine. Chemoprophylaxis. Control is mainly public education on safe sex practices and treating infected individuals
Neisseria meningitidis virulence factors
POLYSIALIC ACID CAPSULE (is an antigenic mimicry. looks similar to host and helps to avoid immune system). Bind human transferrin. lactoferrin. IgA protease. Lipooligosaccharide gives antigenic variation (LOS). Pili.
Clincial diseases of meningitis
Crosses blood-brain barrier. Effects young children under the age of 5 (primarly). Very hard to diagnosis in very young babies. Is transmitted via close contact in aerosol (very hard to contract). Second most common cause of meningits behind S. pneumoniae.
Pathogeneis of Meningococcal disesae
Specific receptors (GD1) for bacterial fimbriae on nocilliated columnar epithelial cells in nasopharynx of host. Taken up intracellurally and repilicate to avoid immune system. Produce endotoxin lipid A. This LIPID A cause the inflammation and most damage. Human only natural host.
Diagnosis of Neisseria meningitis.
GRAM STAIN of sterile CSF. Few host cells. Note bacteria and host cells. About 10 percent of people are healthy naso-pharyngeal carriers. Culture from CSF. blood. and sputum
Epidemiology of Meningococcal disease
Humans only host. Person to person transmission by aerosolization and respiratory tract secretion in crowded contidtions. Highest rate in children younger than 5 years.
Vaccines for bacterial meningitis
There are conjugate vaccines made by attaching antigen to carrier protein. Is a polyvalent vaccine against the N. meningitidis.
About half the children or adutls with meningoccal meningitis have rash that does not fade. The pressure test shows the rash does not fade under pressure.
disseminated septicemia. characterized by petechial skin leisons. Waterhouse-Friderichsen syndrome
Usually a complication of a prior respiratory tract infection. Prognosis is good.
Laboratory Diagnosis of Neisseria meningitidis
Large number of encapsulated small gram-negative diplococci can be seen microscopically in cerebrospinal fluid. Transparent non pigmented nonhemolytic colonies on chococlate agar with enhanced growth in moist atmosphere with 5 percent CO2. OXIDASE POSITIVE. Acide production from glucose and maltsose but not from other sugars.
Treatment of N. meningitidis
Susceptible to penicillin and cephalosporin. Vaccine available. Polyvalent vaccine.
General characteristics of Neisseria spp.
Aerobic. Gram negative cocci often arranged in paris with adacent sides flattedned like coffee beans. Oxidase positive. Nonmotile. Acid from oxidation of carbohydrates. not from fermentation.
Suborder Corynebacterineae. Has seven families with many know gernera such as Corynebacterium. Mycobacterium. nocardia. CMN Group
CMN cell walls
contain waxes with 60 to 90 CARBON MYCOLIC ACID. Acid-fast basic fuchsin dye cannot be removed from cell by acid-alcohol treatment.
Along with Rhodococcus make up the family Nocardiaceae. Develope a stubstrate of mycelium that readily breaks into rods and coccoids elemtns. Look very similar to fungi. Some also form a aerial mycelium. Slow groing (3-5days). AERIAL MYCELIM help to identify it.
Impact of Nocardia
Most are free-living saprophytes. Can degrade many molecules. Some are opportunistic pathogens causing nocardiosis. USUALLY INFECT LUNGS. can infect central nervous system.
Virulence factors of Nocardia
CORD FACTOR. Protects them from phagocytosis. CATALASE AND SUPEROXIDE DISMUTASE (allows them to survive harmful oxygen products)
Clinical Disease caused by Nocardia
Supperative infections. Pus forming infection. Normally causes chronic infections. Main disease is Bronchopulmonary disease (can spread to CNS). Can cause brain abcesses. Or Cutaneous infections (mycetoma slow growing fungal infection that is localized)
Lab Diagnosis and Treatment of Nocardia
Microscopy of sputum samples. Culture on BCYE (buffered charcoal yeast extract). and elevated CO2. ID via rRNA and housekeeping genes. TREATMENT. treat localized infection with sulfa drugs. if disseminated use cephalosporin (broadspectrum).
Genes that code for essential functions. Are constutive genes which are always expressed at a constant level
Primarily infects horses. Can be found in the environment (soil). Very rarely infects humans. Are intracellular bacterium with rod to coccus are pleomorphic.
Clincial disese caused by Rhodococcus equi
1. Abscessses. inflammation (granulomas collection of walled off bacteria by macrophages). 2. Can be invasive and cause pulmonary disese. dissemination to lymph nodes. meninges. skin. COMMON CAUSE OF PHEUMONIA IN ANIMALS. RARE IN HUMANS PRIMARILY IMMUNOCOMPROMISED (AIDS). Does respond to antibiotic treatment VANCOMYOSIN.
General information on Genus Mycobacterium
In family mycobacteriaceae. Are straight or slightly curved rods that sometimes branch or form filaments. Aerobic and catalase positive. Acid fast (long mycolic acid chains). High G +C in their DNA content. Very slow growers. Can be pigmented or not.
Cell wall of Mycobacterium
Lipid rich cell wall. Are poly peptides in the cell wall (PPD). Have mycolic acid.
Causes tuberculosis in cattle and other ruminants.
Are species of Mycobacterium that when exposed to light will enhance their pigmentation. Are NTM (non-tuberculosis mycobacterium). MYCOBACTERIUM KANSASII will change color on middlebrook agar
Mycobacteria pathogenic for humans are differentated by these groups. Are done by speed of growth and production of chromogenic pigment.
Global infection rate of tuberculosis
1.7 billion people infection. About 8.4 million cases and 1.9 million deaths per year. Most cases are from foriegn born ethnic groups. Is spread in close proximities by airborn droplets.
Clinical disease tuberculosis
Primary TB. Secondary TB. or reactivation of TB. Pulmonary TB. Lumph node. CNS menigits. skeletal joints. Miliary TB (micro lesions on lungs seen on Xray)
Diagnosis of Active TB
Microscopy of sputum with an acid fast stain. Chest Xray of the lungs. The tubercuol skin test (PPD). Myocbacterium tuberculosis has mycolic acid which makes it difficult to treat. Must be done with long regiments of antibiotics.
Mycobacterium leprae information
Cant culture in lab. Humans and armidillos are only known species to host the bacteria. Can use mice feet for culturing. Is very slow growing and makes it very difficult to diagnosis.
More server form of the disease. Causes skin condition of macules. Macule is a skin pale lession that is raised or malformed. Not well defined. different sizes. Less than 5 to 10 mm in size. Causes teh decrease of activation of T-helper 1 cells to help clear the disease. REDUCED T-HELPER 1 CELLS. Has increased number of bacteria in this infection
Less severe form of leposry. Characterized by single lesions. Have a white pigmentation.
Mycobacterium tuberculosis and culture
Is grown on lowenstein jensen media and middlebrook 7H10. Is a slow grower. Is found in sputum. BACTEC broth made specifically for rapid growth. (up to 10-12 days).
Intracellular pathogen. Found in immunocompromised peole (AIDS). Located in lungs. Called MAC mycobacterium avium complex
Treatment of Mycobacterium tubuculosis
First line drugs. ISONIAZID (IHN). Rifampin. pyrazinamide (PZA). ethanmbutol. Is a vaccine for TB but is not normally given in US.
Two different populations of TB test
1. Active TB. 2. Positive PPD test.
Antibiotic Resistance in M. tuburculosis
Supsecpted resistance treat with 4 or more 1st line drugs. Resistance developes use 2 new drugs (kanamycin and quinolones). Long term treatment over 2 years. Very expensive and toxic. Drug resistance is increasing as a world wide phenomenon.
The cell wall is the major antigen. The main types to serotype them is by the Flagella (H antigen). Capsule (K or VI antigen). Contain the lipopolysacchardie endotoxin.
Illnesses associated with Enterobacteriaceae
Major causes is gastrointestinal illness. Can also cause infections in CNS. Lower respiratory tract. Blood (septicema). GI tract. and Urinary tract
Most common bacteria of Enterobacteriaceae associated with bacteremia
Escherichia coli about 45 percent.
Definition of Diarrhea
Stool of decreased consistency and increased volume due to imbalance of secretion and absortption of water and salts in the intestine. Large amounts of stool
Gastroenteritis caused by Enterobacteriaceae
1. Secretory (noninflammatory. non invasive). Toxin produced by bacteria stimulate secretion of the salts and electrolytes and decrease absorption of water. 2. Invasive (inflammatory). Actually enters cells and causes damage. (Samonella). 3. Systemic. emcompases all systems
Fecal oral route transmission
5 F's. Fields (soil). fingers. flies. fluids (water). food. Typical transmission route of Enterobacteriaceae. Bacteria is shed in feces.
Preventative Interventions for Diarrhea mortality
Improving food safety. water. sanitation. and hygiene. Breatfeeding (fluids and immunity). Future and current vaccines. Vit. A. Zinc (reduces lenght and severity of diarrhae).
Escherichia coli virulence factors
Most are common residence that are pathogenic. Flagella H antigen. Have genes on plasmids that code for enterotoxins. Colinization factors (adherence). Capsular K antigen helps prevent phagocytosis.
Enterotoxigenic Escherichia coli. Result in cholera diarrhea (is milder). Binds to microvilli and increase cyclic amp production which leads to loss of water and electrolytes. Is a self limiting mild and brief diarrhea. Sudden onset of diarrhea. Rarely accompanied by high fever and vomitting.
Enteropathogenic Escherichia coli. E. coli will adhere to microvilli and block usage of them and cause lesions on the cell. First step is the formation of a bundle forming pilus (intial adherence). For a pedetal then will bind to cell and disrupt the cytoskeleton (intimate) with actin.
Enteroaggregate Escherichia coli. Bind to large and small intestine in a a biofilm formation. In addtion to the decreased surface area many cytotoxins and enterotoxins are released. Make it hard to serotype due to biofilm formation.
Enterohemorrhagic E. coli. Causes hemorrhagic colitis. Stomach cramps. diarrhea (often bloody). and vomiting.(HUS) Complications Hemolytic uremic syndrome. Decreased frequency of urination. feeing very tired. and losing pink color of skin and membrane due to anemia. Can lead to kidney failure
Shiga toxin escherichia coli
About 265k STEC infections each year in the US. O157 CAUSES ABOUT 36 percent of these infections. STEC typically disappear from teh feces by the time the illness is resolved but may be shed for several weaks after symptoms resolve.
Other disease caused by E. coli
Urinary tract infections (ascending. most common casuse). Neonatal meningitis. Septicemia.
Salmonella enterica general info pluse diseases
Has a very low infectious dose. 1. Gastroenteritis (self limiting). 2. Septicemia 3. Typhoid fever (caused by Typhi. Paratyphi A these are only found in humans) high fever. lethargy. GI symptoms. possible rash
Salmonella enterica Typhimurim mechanism for invasion
Will cross the epithelial barrier at the M cells and destroy them. They will enter macrophages and cause apoptosis.
Shigella basic info
Common species. dysenteriae. flexneri. boydii. sonnei. Typically causes bloody diarrhea with fever (dysneteriae). Low infectious dose. Highly transmitable. Humans only host. Very resistant to low pH. can survive in gut. Causes Shigelosis which is fever and bloody diarrhea. Some produce a toxin very similar to shiga toxin. Normally infects children around 7 years old.
Shigella mechanism of intection.
Similar to Salmonella and enter in through the M cell and enter into the macrophage and destroy it. Can move from one cell to another intracellularly.
Yersinia general info
Common species pestis. enterocolitica. pseudotuberculosis. Enterocolitis is a sacrophylic (lives in cold environment). Causes bacteremia and has a high infectious dose. Last a few days to a week. Non specific self limiting diarrhea. Y. pestis Causes the plague not food born like the other is zoonotic. caused by rats (urban) or sylvanic (wild)
Commonly found in nature is all around us. Can cause Pneumoniae. liver abcess. and septicemia. Klebsiella granulomatis is a sexual transmitted disease with low transmission causes ulcerations (granuloma inguinale)
Common cause of UTI and can cause menigitis in neonates. Not really GI causing. Common cause of noscomial infections
Other important enterobacteriaceae
Enterobacter (found in nature commonly occuring). Can cause enterocolitis. Citrobacter (opportunistic bacteria normal GI resident can produce a shiga toxin and HUS). Serratia not found in gut another common cause of noscomial infections.
Lab Diagnosis of Enterobacteriaceae
Use selective media if sample is taken from stool. Sterile sites use a general media. Chemical tests are used to identify bacteria. Uses of API strip.
General Characteristics of Vibrio. Aeromonas. Plesiomonas
Gram negative. Facultative anaerobes. Fermentative bacilli. POLAR FLAGELLA. OXDIASE POSTIVE. Primary found in water sources. Causes gastrointestinal diseases.
Morphology and Physiology of Vibrio
Comma shaped bacilli. V. cholerae. V. parahaemolyticus. V. vulnificus are most significant human pathogens. Can grow in broad temperature and pH for growth on media. Common in environment like warm brackish water. V. cholera CAN GROW WITHOUT SALT.
Ecology of V. cholerae
Have a symbiotic relationship with zooplankton and phytoplankton. Live in warm brackis water. Can live in various salt contents. Found in environment. More common in brackish water.
Vibrio cholerae Pathogensis
After gaining entry into the body will attach to small intestine they multiply and causes secretory diarrhea. The mechanism is similar to ETEC. The Cholera toxin will bind to receptors on the gut and cause increased cAMP activity. Causing the loss of water and salts. Leads to Profuse diarrhea. RICE WATER DIARRHEA.
V. cholera associated disease adn source of infection
Water and food. Causes Gastroenteritis
Comes from raw shellfish. seawater. Causes gastroenteritis. wound infections. and bacteremia. Has a different type of hemolysis. Kanagawa hemolysin associated with pathogenic strains. Is a very alkaline high salt content blood agar is used for culture.
Capsule and pili are essential for virulence. Also has cytolysins and collagenase which will cause tissue destruction. Infections come from saltwater and shellfish. Cause bacteremia. wound infections. cellulitis. ONLY SKIN no GI
Treatment and Prevention of Vibrio cholera
Use cholera cot to measure amount of fluid loss. REPLACE LOST FLUIDS AND SALTS. REHYDRATION. Then comes maintances of fluid loss. Assess for dehydration. rehydrate. monitor. unitil diarrhea stops. Give antibiotics.
Used for culturing Vibrio pathogens. Is a enriched media. contains alkaline peptone. Thiosulfate-citrate-bile salts-sucrose agar is used to differentiate Vibrio species
Ameromonas general info
Gram negative. rods. motile by single polar flagellum. facultative anaerobe. Ubiquitis which cause huge diversity. Cause diarrhea. wound infections and systemic diseases.
V. cholera outbreaks
Increase number in incidents due to poor sanitation and water treatment. A third world disease primarily.
Ameromonas virulence factors
Hemolysins. Enterotoxins. Cytotoxins. Easily adhere to cells.
Main opportunistic bacteria of the aeromonas. Is ubiquitus found in many water systems. Can live for month longer in freshwater due to adaptation of environment.