Loading

G. Xardas. Drake University. 2019.

Non-viable bacilli stain poorly and unevenly as fragmented yasmin 3.03mg for sale, beaded and granular red bacilli buy 3.03 mg yasmin mastercard. When dry, hold fold of skin tightly between the thumb and forefinger until it becomes pale. Using the sterile blade, make a small cut through the skin surface, 5mm long and 2-3mm deep, where the bacteria is be found. Make a small circular smear of the tissue juice (Cover the cut with a small dressing). Wipe the back of the slide clean, and place in a draining rack for the smears to air-dry (protect from direct sun light). Most are soil saprophytes, but some are human pathogens responsible to cause actinomycosis nocardiosis and actinomycetoma. Large group of gram positive bacilli with a tendency to form chains and filaments. Endogenous members of the bacterial flora in the mouth and lower gastrointestinal tract Actinomycosis Chronic suppurative and granulomatous infection with interconnecting sinus tracts that contain sulfur granules Etiology: Actinomyces israeli Actinomyces naeslundii Characteristics:. Gram positive, facultative anaerobe substrate filaments that grow in co2 enriched condition Pathogenesis and clinical features:. Infection is initiated by trauma that introduces these endogenous bacteria into the mucosa 1. Cervico facial actinomycosis 270 Fluctuant mass with draining fistula in jaw area, and may extend to involve bone and lymphnodes in the head and neck 2. Thoracic actinomycosis Resemle subacute pulmonary infection with extension to chest wall and ribs 3. Abdominal actinomycosis May be secondary to ruptured appendix or ulcer with extensive involvement of abdominal organs Lab. Diagnosis: Specimen: Tissue, pus, sputum Smear: Gram-positive filaments with lobulated sulfur granules Culture: Thioglycolate broth or blood agar incubated anaerobically or co2 enriched condition Biochemical reacrion: Catalase positive/negative Treatment: Penicillin Clindamycin + Surgery Erythromycin Nocardiosis Etiology: Nocardia asteroides complex N. Aerobic gram positive, partially aci fast bacilli Pathogenesis and cloinical features: Route of transmission: Inhalation Usual presentation is subacute or chronic pulmonary infection with dissemination to the brain and skin Lab. Spirochete consist of protoplasmic cylinder bounded by a cell wall and outer membrane. There is an axial filament or endoflagella between the cell wall and outer membrane. Not cultured in artificial media, in fertilized eggs and tissue culture, but the saprophytic Reiter strain grows in anaerobic culture. Remain viable in the blood or plasma store at 4 c at least for 24 hrs (transmitted via blood transfusion) Antigenic structure:. Primary stage: Hard chancre: Clean-based, non-tender, indurated genital ulcer with inguinal lymphadenopathy.

Examine at 5 buy generic yasmin 3.03 mg on line,10 discount yasmin 3.03mg on-line, and 18 days for a change in colour of the substrate from amber to pink-red, as shown in colour. Results Pink-red substrate -------------------------------------- Positive test Tween 80 hydrolyzed No change in colour ------------------------------------ Negative test No hydrolysis of Tween 80 81 Controls Positive Tween hydrolysis control: Mycobacterium kansasii. Principle The test organism is cultured in a medium which contains urea and the indicator phenol red. If the strain is urease-producing, the enzyme will beak down the urea (by hydrolysis) to give ammonia and carbon diaoxide. With the release of ammonia, the medium becomes alkaline as shown by a change iin colour of the indicator to red-pink. Examine for urease production by looking for a red- pink colour in the medium as shown in colour. Results Red-pink medium---------------------------------------- Positive test Urease produced No red-pink colour ------------------------------------- Negative test No urease produced Controls Positive urease control: Proteus vulgaries. At room temperature O (22-293 c), the species is motile and shows a stronger urease reaction. Under alkaline conditions and exposure to the air, the acation produced from the fermentation of the glucose is oxidized to diacetyl which forms a pink compound with the creatine. Inoculate 2ml of sterile glucose phosphate peptone water O with the test organism. Add about 3ml of the sodium hydroxide reagent and shake well, Caution: The sodium hydroxide reagent is corrosive, therefore handle with care and do not mouth – pipette. Results Pink – red colour -------------------------------------- Positive test Acetoine produced No pink – red colour ---------------------------------- Negative test No acetoin produced 84 Controls V-P Positive control: Enterobacter aerogenes or Klebsiella pneumoniae V-P Negative control: Escherichia coli. Col factors: Plasmids which contain genes that code for extracellular toxin (colicines) production that inhibit strains of the same and different species of bacteria. F(fertility) factors: Plasmids that can recombine itself with the bacterial chromosome. It promotes transfer of the chromosome at a high frequency of recombination into the chromosome of a second (recipient) bacterial cell during mating. Transposition Mechanism which enhances genetic flexibility among plasmids and bacterial chromosomes. When transposons transfer to a new site, it is usually a copy of the transposon that moves, the original transposon remaining in situ. Transposons code for toxin production, resistance to antibiotics as wellas other fuctions. Disinfection: Destruction of microbes that cause disease; may not be effective in killing spores. Antisepsis: destruction or inhibition of microorganisms in living tissue there by limiting or preventing the harmful effect of infection. Chemical methods of sterilization and disinfection These chemical agents destroy any type of microbes with out showing any form of selectivity unlike antibiotics.