Molecular Microbiology Case Study Example | Topics and Well Written Essays - 1500 words

Molecular Microbiology - Case assume ExampleThe commoner intravenous catheter-related infections are exit-site infections, as in this case, often with erythema around the area where the cable system penetrates the skin.Bacterial broth stream infections are common in this given scenario, and Staphylococci are the endorse most prevalent bacteria. However, a smear suggesting the staphylococci or compulsive cocci in clusters in blood culture as in here, is not sufficient for the diagnosis of true bacterial blood stream infection before the species is identifiable, since the most frequent of this species, Coagulase-negative staphylococci or CoNS usually habituate in the skin, and there is always a chance of contamination of the culture bottlefuls during the venipuncture. In contrast, such an infection cod to staphylococci aureus is virulent by its intrinsic nature, and isolation in one blood culture bottle is clearly diagnostic and is an indication of initiation of antibiotic thera py. Thus the therapeutic decision devising is base on identification of the organism (Beekmann, S. E., Diekema, D. J. and Doern, D. J., 2005).The first shew obviously would be to do a start microscopic examination. Direct microscopic examination may provide a rapid, presumptive report of Gram-positive cocci resembling staphylococci. Isolation of S. aureus should be performed using 5% blood agar following an incubation uttermost of 18-24 h in air at 35-37 C. Staphylococcus aureus ferments mannitol, resulting in a change in the work of the medium from pink to yellow. Colony morphology may be used by the experienced commentator to define presumptive staphylococci. A Gram stain appearance of cocci in clusters and a positive catalase test provide rapid indicators of staphylococci. However, in order to be able to distinguish between Staphylococcus aureus and the remaining members of the staphylococcus species, other tests are necessary. For clinical microbiological purposes, two or three simple tests suffice. The coagulase test detects the production of coagulase by S. aureus. In this test, one colony is mixed with plasma, incubated at 37 C for 4 h and ascertained for clot formation. Samples that are negative at 4 h are incubated and observed again for clotting at 24 h. The slither agglutination test detects clumping factor (ClfA). This is performed by making a heavy homogenous suspension of cells in distilled water on a glass slide to which a drop of plasma is added. Within 10 s, the mixture is examined for presence of clumping (Chapin, K., and M. Musgnug, 2003).How would you differentiate the cocci in clusters from those in chainCocci in clusters are named as staphylococci. All staphylococci have the might to convert hydrogen peroxide into nontoxic H2O and O2. Both coagulase positive and negative staphylococci elicit catalase. This test differentiates them from cocci in chain or streptococci, which preservenot produce catalase and hence are catalase neg ative (Chapin, K., and M. Musgnug, 2003).What is the regulation of DNase test and what is the identity of this organism and why Support your answer with microbiological diagnostic facts.DNase or deoxyribonuclease is an extracellular enzyme that can hydrolyze deoxyribonucleic acid to oligonucleotides. Several varieties of deoxyribonucleases are distinguished on the basis of antigenic properties, response to inhibitory substances, hydrolytic end products, and