2nd term lecture,_enterics,_psuedo,_bru,_borde,_hemoph,not_midterm
2010-20112nd Term 2nd Semester
Properties of Enterobacteriaceae Found in intestines of humans and animals G+C ration is 39-59% Phylogenetically closely related Type genus is Escherichia coli Gram-negative facultative anaerobic rods Motile except Shigella and Klebsiella Optimum Temp 35oC-37oC Fermentation prefered: Oxidation-reduction of glucose anaerobicaly generating alcohols, acids, CO2 gas Oxidase negative, Catalase positive Nitrate is reduced extract oxygen from NO3 reducing it to (NO2)
Types of E. coli Enteropathogenic E.coli (EPEC)Entrotoxigenic E. coli (ETEC) E. coli enteroinvasive (EIEC)E. coli enterohemmoragic (EHECO157:H7, Humpergur E. coli enteroaggregative (EAEC)
Diagnostics EnteroScreen 4™single test for non-lactose-fermenting, oxidase-negative, enteric pathogensLys deNH3 H2SLysdecooHase Urease
MacConkey Agar and Eosin Methylene Blue (EMB) agar both are: Differential medium for lactose fermentation Differentiates lactose fermenters and non-fermenters Selective medium Selects enteric gram negatives and Inhibit gram positives Specimens: Feces,, sputum, urine, wound, peritoneal flulids: MAC or EMB EMB MacConkey
Salmonella-Shigella (SS) AgarSelective for Salmonella and Shigella speceis black colonies
Biochemical tests Indole, Methyl Red, Voges-Prosakaur, Citrate (IMViC) Tests detects: Glucose fermentation resulting in mix-acids OR neutral pathways producing Acetoin Citrate and urease utiliztions Most tests are included in recent technologies like API, Vitek,
Advanced Identification kits 1. ABI kit2. Vitec Kits:All media or antibiotics are tested in this cardAnd the computer reads out the card after 8-12 hours Card
Pseudomonas aeruginosaProperties Gram-negative rods. Motile with polar flagella. Obligate aerobe. Oxidase-positive. Do not ferment carbohydrates. Resistant to multiple drugs.
P. aeruginosa Clinical Diseases Infection of wounds and burns (blue-green pus). Skin and nail infections Pulmonary infection Necrotizing pneumonia in Cystic Fibrosis patients Eye infections: corneal ulcer. Ear infections Otitis externa: swimmers Endocarditis Urinary tract infection
P. aeruginosaForms fluorescent greenish colonies, sweetodor, and b-hemolysis.•Pyocyanin- nonfluorescent bluish pigment;•pyoverdin- fluorescent greenish pigment;•pyorubin, and pyomelanin•Some strains have a polysaccharide capsule.•Identification of P. aeruginosa is usually based oncolonial morphology, b-hemolysis, oxidasepositivity, the presence of characteristic pigmentsand sweet odor, and growth at 42 oC.
Brucellosis: Brucella spp. 1887 by Dr. David Bruce. Zoonotic disease Transmitted by animals and their products Gram negative, coccobacilli bacteria Facultative, intracellular organism Environmental persistence Temperature, pH, humidity Frozen and aborted materials
Brucella: Properties Highly contagious zoonotic disease Also known as undulant fever(intermittent), Malta fever, Gibraltar fever, Bangs disease, or Mediterranean fever, Brucellosis mostly is occur in people who work with livestock It is an intracellular parasite, and can be congenital Zoonotic Species in animals B. abortus in cattle B. suis in hogs B. melitensis in goats and sheep Symptoms :intermittent fever, sweating, chills, aches, and mental depression.
Diagnosis in Humans Isolation of organism Blood, bone marrow, other tissues Serum agglutination test Four-fold or greater rise in titer Samples 2 weeks apart Immunofluorescence Organism in clinical specimens PCR Treatment tetracyclines (with streptomycin), co-trimoxazole, and sulfonamides, is effective. Bed rest is also imperative Center for Food Security and Public Health, Iowa State University, 2008
Bordetella pertussis: Whooping Cough Well known Infects only man, (child hood disease) Aerobic, Gram negative coccobacilli highly communicable through Respiratory tract Whooping cough. Produce endotoxin, pertusis toxin Three stages of disease Catarrhal: runny nose, low fever, and mild cough 1-2wks Paroxysmal stage: repetitive coughing 1-6 wks Convalescent stage: final, weeks to months Diagnosis Isolation, PCR, direct fluorescent antibody, and serology Treatment Erythromycin, Azithromycin, and clarithromycin Vaccine: part of regular vaccination schedule (See tetanus, DTP)
Haemophilus Spp (Blood/heme loving) Small, nonmotile, pleomorphic, Gram negative, coccobacilli, obligate parasites of man and animals Isolated in an influenza Pandemic 1890 and was mistakenly considered the cause of influenza until Influenza virus was confirmed. Contrary to what the name suggests, the bacterium does not cause influenza Occurs in two forms virulent capsulated and noncapsulated Aerobic, could be facultative anaerobic, fastidious require X factor (i.e., hemin) and V factor (NAD or NADP)to grow chocolate blood agar which is prepared by adding blood to an agar base at 80oC. The heat releases X and V factors from the RBCs and turns the medium a chocolate brown color. H. Influenza type b is the major pathogen (95% of human disease) Man and animals are only natural hosts, highly adapted to man H. Ducreyi STD (soft chancroid) not common Opportunistic pathogens with uncommon or rare infections include: H. Aphrophilus, H. Parapgrophilus, H. Parainfluenza, H. haemolyticus, H. Parahemolyticus, H. segnis
H. Influenza have no specific syndrome but can cause: meningitis, conjunctivitis, sinusitis, cellulitis, otitis, epiglottitis, pneumonia,Health Canada and www.cdc.gov/vaccines/pubs
According to WHO 3 million serious illnesses, 386 000 deaths uder age of 5, per year by meningitis and pneumonia Important secondary invader to influenza virus In swine influenza in pigs, association between the virus and Haemophilus suis is necessary for the disease. Similar association between human influenza virus and H. influenzae seen in chick embryos and infant rats. The fight between Streptococcus pneumoniae In vitro Strep pneumoniae wins In vivo H. Influenza wins In vivo H. Influenza signals host immune system against S. pneumoniae, the former is not well affected
One of the most transformable genomes: First genome 1995 H. Influenza was the first free living organism to have the complete genome sequenced in 1995 by The Institute for Genomic Research (TIGR) now the J. Craig Venter Institute Why is it highly adapted Transformable by many ways, by first making “blebs” in outer membrane The genome consists of 1,830,140 base pairs of DNA in a single circular chromosome that contains 1740 protein-coding genes, 58 transfer RNA genes tRNA, and 18 other RNA genes. The sequencing method used is whole-genome shotgun, which was completed and published in Science in 1995 and conducted at The Institute for Genomic Research.[12
Diagnosis Microscopy to detect in CSF, synovial fluids, Culturing, difficult, may be not sensitive latex particle agglutination test (LAT) PCR
cefotaxime , ceftriaxone, ampicillin and sulbactam, cephalosporins of the second and third generation, or fluoroquinolones are preferred. Hib conjugate vaccine Hib is preventable, The two major obstacles to prevention of Hib disease are a shortage of information and a shortage of money Shortage of info: difficult to diagnose, it causes death without being recognized Hib vaccine is expensive in 2005, it costs roughly seven times the total cost of vaccines against measles, polio, tuberculosis, diphtheria, tetanus, and pertussis.
H.influenza: Hidden disease, diagnostics, and treatment dilema. How Hib goes undergound Does not cause a unique disease syndrome, but deadly forms are pneumonia and meningitis But other bacteria also cause pneumonia and meningitis Doctors respond first with Antibiotics to childhood pneumonia or meningitis However, to confirm a case of Hib samples must be taken: a blood specimen in the case of pneumonia, a spinal-fluid specimen by lumbar puncture in the case of meningitis and the bacteria must then be isolated from those specimens in a laboratory...a challenge even for sophisticated laboratories In developing countries, these tests may not be made at all, or laboratories may fail to carry them out correctly, or Hibs presence may be masked because antibiotics were given before the samples were taken The hidden nature of Hib...this is how Hib is underestimated A "Rapid Assessment Tool" has been developed by WHO and CDC to make sensible estimates of Hib