Pharmacology and Infection Control in Clinical Practice NUR2505

All answers MUST include appropriate intext references throughout all parts, unless otherwise stated.
As a rough guide, write approximately 15-17 words per mark.

Student name (LAST NAME first name):
Student ID number:

1.Cefazolin (Total 20 marks)
Answer (approximately 75 words for part a, and 225 words for part b):

a. Immediately after his surgery, Peter was given prophylactic antibiotic therapy to avoid any potential infections as a result of his body being compromised of its primary and secondary defences (Lee & Bishop, 2016). Antibiotics are administered to keep the potential infection at bay in Prophylaxis therapy (Bullock & Manias, 2022). When an individual undergoes surgery, their primary defence mechanism, the skin is compromised, and this can result in leukocyte activity and inflammation (Craft et al., 2023). Medicines such as Cefazolin can help alleviate this risk by fighting the bacteria that may have entered the body through the surgical site (Lee & Bishop, 2016).

b. Structurally like penicillin, Cefazolin, is a first-generation cephalosporins antibiotic that is a beta-lactam antibiotic (Bullock & Manias, 2022). It inhibits the synthesis of bacterial cell walls, a mechanism that involves the binding of the beta-lactam ring of Cefazolin to PBP enzymes (penicillin-binding proteins) that are situated near the bacterial cell membrane (Burchum & Rosenthal, 2018). These enzymes are critical for enhancing the bacterias structural integrity and Cefazolin prevents this from happening by interrupting the cell wall synthesis and weakening the bacterias structural integrity (Burchum & Rosenthal, 2018).

The plasma membrane surrounds the human cells without a peptidoglycan layer and this ensures that while Cefazolin works on bacteria, it does not harm the human cells (Lee & Bishop, 2016). Due to the selective characteristics of Cephalosporins like Cefazolin, they are frequently used in post-surgical treatments to prevent infections (Lee & Bishop, 2016).
The antibacterial effects of Cefazolin are limited to extracellular pathogens, due to its inability to penetrate the mammalian cells (Lee & Bishop, 2016). The PBPs only enhance its safety profile, making it slightly against Gram-negative bacteria and particularly effective against Gram-positive bacteria, usually responsible for infections at surgical sites (Burchum & Rosenthal, 2018). These selective targeting properties of Cefazolin in particular help manage bacterial infections ineffectively, especially among post-surgery patients (Burchum & Rosenthal, 2018). These cephalosporins antibiotics also have minimal to no side effects on patients thus making them safe for use among vulnerable individuals who have undergone surgery (Burchum & Rosenthal, 2018).

2.UTI and standard precautions (Total 15 marks)
Answer (approximately 135 words for part a, and 90 words for part b):

a.Peters risk of UTI (urinary tract infection) is higher due to the presence of an IDC (indwelling urinary catheter) (Lee & Bishop, 2016). Several factors increase his risk of UTI, they are:
1.The process of inserting and maintaining the IDC can introduce bacteria if aseptic protocols are not followed strictly (Lee & Bishop, 2016). This results in the bacteria being introduced into the urinary tract from external sources, and repeated contact with the catheter or drainage bag further increases the chances of contamination by Escherichia coli (Lee & Bishop, 2016).
2.The IDC allows the formation of bacterial biofilms on its surface and these biofilms, in turn, protect the bacteria from the bodys defence mechanism (Craft et al., 2023).
3.The IDC is a direct path for the bacteria to move upwards towards the bladder from the urethra, as it can bypass the flushing effect of urine, the bodys natural immune system (Lee & Bishop, 2016).
b.When put together, these factors create a conducive environment for the bacteria to grow among vulnerable patients like Peter.

1.Use of Personal Protective Equipment (PPE): The use of proper PPE such as gloves and masks ensures that there is no bacterial transmission from the nurse to the patient and vice versa (Craft et al., 2023). They form a barrier between the infectious urine and the nurse and help avoid contamination (Craft et al., 2023).

2.Hand hygiene: Hand hygiene involves the nurse washing and sanitising their hands before and after emptying Peters IDC bag (Craft et al., 2023). The nurse should ensure to use soap and water to clean their hands before putting on protective gloves and only then change the IDC bag (Craft et al., 2023)

3.Culture & Sensitivity (Total 20 marks)
Answer (approximately 75 words for part a, 90 words for part b, 75 words for part c, and 60 words for part d):

a. A urine culture is performed to identify the exact bacteria causing the UTI. It could be organisms such as Escherichia coli, or any other bacteria (Bullock & Manias, 2022). A culture helps determine the susceptibility of the bacteria to the different antibiotics (Bullock & Manias, 2022).

Antibiotic sensitivity testing is done using a disk diffusion method. It involves an agar plate being inoculated with the pathogen and an antibiotic-impregnated disk placed on it (Bullock & Manias, 2022). Once the antibiotic begins to diffuse into the agar, it stops the bacterial growth and forms a zone of inhibition around the disk (Lee & Bishop, 2016). The size of this zone indicates the effectiveness of the antibiotic on the bacteria. The larger the zone, the more effective the antibiotic, and vice versa (Bullock & Manias, 2022).

b. Based on the inhibition measurements provided (A=15 mm, B=25 mm, and C=10 mm), the effectiveness of each of the three antibiotics against Escherichia coli bacteria is as follows:

1.Antibiotic A (Ampicillin, 15 mm): Since the zone is only 15 mm, it indicates that the bacteria are slightly susceptible to Ampicillin, but it may not be enough to provide a complete treatment (Burchum & Rosenthal, 2018).

2.Antibiotic B (Ciprofloxacin, 25 mm): This is the largest among the three zones, suggesting that the antibiotic B, Ciprofloxacin is highly effective in inhibiting the bacteria and therefore can be given to Peter (Burchu m & Rosenthal, 2018).

3.Antibiotic C (Cefazolin, 10 mm): The zone for antibiotic C, Cefazolin is the smallest, suggesting that the bacteria is resistant to the antibiotic and therefore should not be used in this case (Burchum & Rosenthal, 2018).

c. Since antibiotic B, Ciprofloxacin has the largest zone of inhibition (25mm), it will be the most effective in treating Peters UTI (Bullock & Manias, 2022). A large zone indicates that the bacteria is highly susceptible to the antibiotic and therefore the most appropriate (Bullock & Manias, 2022). The fluoroquinolone in the abtibiotic inhibits the generation of DNA gyrase and topoisomerase IV in the bacteria (Burchum & Rosenthal, 2018). These enzymes are essential for cell repair and replication and inhibiting their growth can prevent the bacteria from reproducing therefore leading to its termination (Burchum & Rosenthal, 2018). This is a highly effective system as it does not affect the human cells while it nullifies the bacterial cells (Burchum & Rosenthal, 2018).

d. The urine culture suggests that the zone of inhibition for Cefazolin was only 10 mm, the least of the three antibiotics (Burchum & Rosenthal, 2018). Therefore, despite the prophylactic IV Cefazolin, Peter may have developed the UTI due to the bacteria being highly resistant to this antibiotic (Burchum & Rosenthal, 2018). To make matters worse, the presence of an IDC could have facilitated the ingress and multiplication of the bacteria (Burchum & Rosenthal, 2018).

4.Allergic reaction and Loratadine (Total 15 marks)
Answer (approximately 150 words for part a, and 75 words for part b):

a. Sometimes, when patients are exposed to antibiotics, their immune system identifies it as an allergen. This is a typical type I hypersensitivity reaction (Craft et al., 2023). This happens when cells like dendritic, APCs (antigen-presenting cells), process and present the allergen to T-helper cells, who then activate B cells to produce antibodies specific to the allergen, IgE (Immunoglobulin E) (Craft et al., 2023).

On exposure, the IgE binds to the receptors on the mast cells and when re-exposed, they release inflammatory mediators such as histamine which cause rashes, hives, itching, and other allergic reactions (Craft et al., 2023). While histamine increases the vascular permeability causing itching, redness, and swelling, other mediators such as leukotrienes and prostaglandins contribute to the inflammatory response (Craft et al., 2023). This cascade of immune reactions resulted in the allergic reaction that Peter experienced when he was administered the IV antibiotic (Craft et al., 2023). His immune system recognised the antibiotic as an allergen and overreacted to it through a type I hypersensitivity reaction (Craft et al., 2023).

b. Peter was prescribed Loratadine to combat his allergic reaction to the antibiotics. Loratadine is known to be an antihistamine that blocks histamine H1 receptors and prevents from it binding to these receptors (Craft et al., 2023). This helps reduce the allergic response and provides some relief from itching and redness (Craft et al., 2023). Since histamine is the main aggravator of the allergic reaction, blocking its action, Loratadine helps alleviate the allergic symptoms without crossing the blood-brain barrier (MIMS Online, 2024).

5.Trimethoprim (Total 10 marks; approximately 150 words)
Answer:

The synthesis of tetrahydrofolic acid helps form the folate needed to produce DNA replication in bacteria (Bullock & Manias, 2022). This is because of the bacterial dihydrofolate reductase, the enzyme involved in the formation of this DNA. Trimethoprim helps inhibit this process by blocking dihydrofolate reductase (Bullock & Manias, 2022). The bacterias ability to synthesise the nucleic acids and proteins is inhibited, ultimately causing it to perish (Bullock & Manias, 2022).

While Trimethoprim is highly effective in curbing bacterial growth, it does not affect human cells in any significant manner, making it a very effective antibiotic (Burchum & Rosenthal, 2018). This selective ability of Trimethoprim can prove to be useful in treating bacterial infections. Human cells have folate sources through dietary intake, but, bacteria can only synthesise it (Bullock & Manias, 2022). This dependency structure allows Trimethoprim to target bacterial cells without harming human cells and therefore is considered a safe and reliable antibiotic in treating UTIs (Bullock & Manias, 2022).

Are you struggling to keep up with the demands of your academic journey? Don't worry, we've got your back!
Exam Question Bank is your trusted partner in achieving academic excellence for all kind of technical and non-technical subjects. Our comprehensive range of academic services is designed to cater to students at every level. Whether you're a high school student, a college undergraduate, or pursuing advanced studies, we have the expertise and resources to support you.

To connect with expert and ask your query click here Exam Question Bank