Cultures of a bacterial species were incubated on the shelf of a refrigerator, out on a lab bench top, on the shelf of a 37°C incubator, and on the shelf of a 50°C incubator After incubation, there was no growth at 37°C and 50°C, slight growth out on the bench top, and abundant growth at refrigeration. What term could be used for this species?
Halophile
Anaerobe
Mesophile
Psychrophile
Capnophile
The Correct Answer is D
A. Halophile: Halophiles are organisms that thrive in high-salt environments. The description of temperature-based growth does not indicate a preference for saline conditions, so this term would not apply to the observed growth pattern.
B. Anaerobe: Anaerobes are organisms that grow in the absence of oxygen. The scenario focuses on temperature preferences, not oxygen requirements.
C. Mesophile: Mesophiles grow optimally at moderate temperatures, typically between 20°C and 45°C, with 37°C being ideal for many human-associated mesophilic bacteria. Because this species did not grow at 37°C or 50°C, it does not fit the definition of a mesophile.
D. Psychrophile: Psychrophiles are organisms that thrive at cold temperatures, usually with optimal growth at 0–15°C and survival at temperatures below 20°C. The abundant growth in the refrigerator and minimal growth at room temperature, with no growth at 37°C or higher, indicates that this species is adapted to cold environments, fitting a psychrophile definition.
E. Capnophile: Capnophiles require elevated levels of carbon dioxide for optimal growth. The growth pattern described is based on temperature rather than carbon dioxide levels, so this term is not applicable.
Nursing Test Bank
Naxlex Comprehensive Predictor Exams
Related Questions
Correct Answer is C
Explanation
A. do not cause many human infections: While some fungi, protozoa, and helminths cause fewer infections compared to bacteria, the main limitation in drug development is not the frequency of infections. Even common infections like candidiasis or malaria require treatment, so infection prevalence alone does not explain the scarcity of effective drugs.
B. have fewer target sites compared to bacteria: These organisms do possess cellular structures that could be targeted, such as cell membranes, enzymes, or nucleic acids. The issue is not the number of potential targets but the similarity of those targets to human cells, which complicates drug design.
C. are so similar to human cells that selective drug toxicity is difficult to achieve: Fungi, protozoa, and helminths are eukaryotic, like human cells, meaning their cellular structures and metabolic pathways closely resemble those of the host. This similarity makes it challenging to develop drugs that are toxic to the pathogen but safe for human cells, limiting the number of available therapeutic options.
D. are parasites found inside human cells: While intracellular parasites pose delivery challenges for drugs, this is not the primary reason for the overall scarcity of antifungal, antiprotozoan, and antihelminth medications. Drug development is limited mainly by eukaryotic similarity rather than intracellular location alone.
E. are not affected by antimicrobics: This is incorrect because antifungal, antiprotozoan, and antihelminth drugs do exist and can be effective. The challenge is creating agents that selectively target these organisms without harming human cells, not an inherent resistance to all antimicrobial agents.
Correct Answer is A
Explanation
A. Coccus: A coccus is a spherical or round-shaped bacterium. Cocci can exist singly, in pairs (diplococci), chains (streptococci), clusters (staphylococci), or other arrangements depending on their pattern of division. The shape is an important morphological characteristic used in bacterial identification and classification in clinical microbiology.
B. Bacillus: A bacillus refers to a rod-shaped bacterium. Bacilli can occur singly or in chains and may be aerobic or anaerobic. Their elongated shape distinguishes them from cocci and influences how they move, attach to surfaces, and form spores.
C. Vibrio: A vibrio is a comma-shaped or curved rod-shaped bacterium. Vibrio species, such as Vibrio cholerae, are typically associated with aquatic environments and have distinct motility patterns. Their curved morphology differentiates them from cocci and bacilli.
Whether you are a student looking to ace your exams or a practicing nurse seeking to enhance your expertise , our nursing education contents will empower you with the confidence and competence to make a difference in the lives of patients and become a respected leader in the healthcare field.
Visit Naxlex, invest in your future and unlock endless possibilities with our unparalleled nursing education contents today
Report Wrong Answer on the Current Question
Do you disagree with the answer? If yes, what is your expected answer? Explain.
Kindly be descriptive with the issue you are facing.