Consider the photos here which demonstrate antibiotic sensitivities of Staphylococcus aureus strains as determined by the Kirby-Bauer method. Abbreviations are as follows: C = chloramphenicol; CC = clindamycin; CZ = cefazolin; E = erythromycin; NOR = norfloxacin; OX = oxacillin; P = penicillin; RA = rifampin; SAM = sulbactam-ampicillin; SXT = sulfatrimethoprim; TE = tetracycline; VA = vancomycin.Imagine that only two cellular changes occurred in the original strain (the first image, on the top) that resulted in the resistance pattern of the strain in the second image (on the bottom). Which combination of mechanisms could explainthese results?Choose one or more:A.expression of efflux pumpsB.overproduction of PABAC.production of β-lactamaseD.altered penicillin-binding proteinE.modification of either 50S or 30S ribosomal subunitsF.altered DNA gyrase ### Antibiotic Sensitivity Testing: Disk Diffusion MethodThe image displays a petri dish used for antibiotic sensitivity testing, specifically using the disk diffusion method. In this method, antibiotic-impregnated disks are placed on an agar plate inoculated with a bacterial strain to evaluate the efficacy of various antibiotics. The presence of clear zones around the disks, known as zones of inhibition, indicates the effectiveness of each antibiotic against the bacterial strain.### Key Components in the Petri Dish Image:#### Antibiotic Impregnated Disks:- **CC (Clindamycin)**- **RA (Rifampin)**- **VA (Vancomycin)**- **E (Erythromycin)**- **NOR (Norfloxacin)**- **OX (Oxacillin)**- **SAM (Ampicillin/Sulbactam)**- **SXT (Sulfamethoxazole/Trimethoprim)**- **TE (Tetracycline)**- **P (Penicillin)**- **CZ (Cefazolin)**- **C (Chloramphenicol)**### Explanation of the Zones of Inhibition:A clear zone around an antibiotic disk signifies that the bacteria are susceptible to that particular antibiotic, meaning the antibiotic is effective in inhibiting bacterial growth. The size of the inhibition zone can be measured to determine the degree of bacterial susceptibility:- **Large Zones of Inhibition**: Indicate high sensitivity of the bacteria to the antibiotic.- **Small Zones of Inhibition or No Zone**: Suggest resistance of the bacteria to the antibiotic.### Educational Value:This image provides a visual representation of how antibiotic sensitivity is tested in microbiology. By assessing the zones of inhibition, clinicians can determine the most effective antibiotics for treating bacterial infections. This is a critical step in combating antibiotic resistance and ensuring the appropriate use of antibiotics in clinical settings. ### Antibiotic Sensitivity Testing: Kirby-Bauer Disc Diffusion Method**Image Description:**The image shows a Petri dish containing a bacterial culture subjected to the Kirby-Bauer disc diffusion method, a technique used to test the efficacy of different antibiotics against bacteria. Small discs impregnated with various antibiotics have been placed on the surface of the agar plate. There are clear zones of inhibition around several of the discs, indicating that these antibiotics effectively inhibit bacterial growth in those areas.**Labeled Antibiotic Discs:**Each disc is labeled with a code indicating a specific antibiotic:- **CC:** Clindamycin- **RA:** Rifampin- **VA:** Vancomycin- **NOR:** Norfloxacin- **SXT:** Trimethoprim-Sulfamethoxazole- **CZ:** Cefazolin- **C:** Chloramphenicol- **TE:** Tetracycline- **E:** Erythromycin- **SAM:** Ampicillin-Sulbactam- **OX:** Oxacillin- **P:** Penicillin**Explanation of Zones:**- **Zone of Inhibition:** The clear, circular areas around the antibiotic discs where bacterial growth has been prevented. The size of these zones is measured to determine the sensitivity of the bacteria to each antibiotic.- **Interpretation:** Larger zones of inhibition typically indicate greater effectiveness of the antibiotic against the specific bacterial strain. Conversely, smaller or nonexistent zones may indicate resistance.**Arrow Indicator:**- An arrow is pointing towards the **OX** (Oxacillin) disc, highlighting the measurement or a significant observation, possibly a notable finding such as antibiotic resistance or effectiveness.**Educational Insights:**- **Kirby-Bauer Method:** This image provides a practical illustration of the Kirby-Bauer method, greatly beneficial for students learning about microbiology and antibiotic resistance.- **Antibiotic Sensitivity:** Understanding the variances in the zones of inhibition helps in determining appropriate antibiotic therapies for bacterial infections.- **Clinical Relevance:** The accurate interpretation of these results is critical in both clinical and laboratory settings to effectively treat infections and curb the spread of resistant bacterial strains.By examining such images, students and professionals can gain a deeper understanding of bacterial behavior in response to different antibiotics, ultimately guiding appropriate clinical decisions and promoting better healthcare outcomes.

Antibiotics are medications that are used to treat infections caused by microorganisms such as…

Answered: Consider the photos here which…

11th Edition

ISBN:9780134580999

Author:Elaine N. Marieb, Katja N. Hoehn

Publisher:Elaine N. Marieb, Katja N. Hoehn

Chapter1: The Human Body: An Orientation

Section: Chapter Questions

Problem 1RQ: The correct sequence of levels forming the structural hierarchy is A. (a) organ, organ system,...