Microbiology Lab


1.What are the three ways in which urinary tract infections may beacquired?

a)Catheter-acquired urinary tract infections (cUTIs). The infection iscommon in people who are fitted with indwelling catheters (Nicolle,2008).

b).Sexually transmitted UTI – persons infected with the disease candeposit the bacteria in a healthy person if they are havingunprotected sex. Moreover, the germs may be pushed into the urethraduring coitus (Nicolle, 2008).

c).Vesicoureteral reflux (VUR) – abnormal backward urine movement fromthe bladder into kidneys or ureters. In healthy human beings, urinemoves flow from the kidneys into the ureters and then bladder.Anatomy change that may result from physical conditions such aspregnancy can cause UTI infection (Nicolle, 2008).

2.What are the primary and secondary antibody responses to animmunogenic response? Describe.

Primaryresponse refers to the immune reaction that occurs the first time anantigen is exposed to the body, with given antibodies appearing inthe blood after a latent period of several days. The new antibodiesdesigned to combat a similar antigen in the future is stored in thecell so that the cells can respond faster to future antigen threats(Nicolle, 2008).

Onthe contrary, secondary immune response occurs on the second, third,and other subsequent exposures to a familiar antigen. The immunityresponse occurs within a shorter time compared to the primaryimmunogenic since the body already has the cells it requires forresisting the introduced antigens (Nicolle, 2008).

3.What is the importance of acute and convalescent serum specimens forthe serologic diagnosis of infection? Explain.

Theacute and convalescent serum specimens are crucial because theyprovide a definitive diagnosis of a given disease. They are mainlyessential in the diagnosis of respiratory diseases as doctors cannotair to determine possible infections. Titers of antibodies againstsuspected viruses or bacteria can be evaluated in sera and then usedto provide valuable assistance towards confirmation of polymerasechain reaction (PCR) and the culture outcome (Stevens, 2010).

Alab technician can enhance the accuracy of both acute andconvalescent serologic diagnosis of infections through optimaltiming. For acute serum specimens, they should be acquiredapproximately seven days after symptoms of a given disease appears.They should then be submitted to a laboratory for testingimmediately. On the other hand, convalescent specimens are collectedand submitted within three to six weeks after the first symptomsappeared in order to get the most accurate results (Stevens, 2010).


Nicolle,L.E. (2008). Health Care–Acquired Urinary Tract Infection: TheProblem and Solutions. Agencyfor Healthcare Research and Quality. Web, retrieved fromhttp://www.webmm.ahrq.gov/perspective.aspx?perspectiveID=68

Stevens,C. D. (2010). Clinicalimmunology &amp serology: A laboratory perspective.Philadelphia, PA: F.A. Davis.