Skip to main content
Ch. 23 - Microbial Diseases of the Cardiovascular and Lymphatic Systems
Tortora - Microbiology: An Introduction 14th Edition
Tortora14th EditionMicrobiology: An IntroductionISBN: 9780138200398Non è quello che usi tu?Cambia libro di testo
Capitolo 19, Problema 7

Use the following choices to answer the question given below:
a. Brucellosis
b. Malaria
c. Relapsing fever
d. Rocky Mountain spotted fever
e. Ebola
The patient’s fever spikes each evening. Oxidase-positive, gram-negative coccobacilli were isolated from a lesion on his arm. What is your diagnosis?

Guida verificata passo dopo passo
1
Step 1: Analyze the clinical symptom described — the patient's fever spikes each evening. This pattern is characteristic of certain infectious diseases, particularly those with cyclical fever patterns.
Step 2: Consider the microbiological characteristics of the isolated organism: it is oxidase-positive, gram-negative coccobacilli. This information helps narrow down the possible pathogens.
Step 3: Review the list of diseases and their typical causative agents: for example, Brucellosis is caused by Brucella species (oxidase-positive, gram-negative coccobacilli), malaria is caused by Plasmodium (a protozoan, not bacteria), relapsing fever is caused by Borrelia (spirochetes, not coccobacilli), Rocky Mountain spotted fever is caused by Rickettsia (gram-negative coccobacilli but oxidase-negative), and Ebola is a virus.
Step 4: Match the clinical presentation (fever spikes each evening) and microbiological data (oxidase-positive, gram-negative coccobacilli) to the most likely diagnosis from the given options.
Step 5: Conclude that the diagnosis corresponds to the disease caused by the organism matching both the clinical and microbiological features.

Risposta video verificata per un problema simile:

Questa soluzione video è stata consigliata dai nostri tutor come utile per risolvere questo problema.
Durata del video:
1m

Concetti chiave

Ecco i concetti essenziali che devi comprendere per rispondere correttamente alla domanda.

Clinical Presentation of Relapsing Fever

Relapsing fever is characterized by recurring episodes of fever that typically spike and then subside, often in a cyclical pattern such as daily or every few days. Recognizing this pattern helps differentiate it from other febrile illnesses. The fever spikes each evening in this case suggest a relapsing pattern typical of relapsing fever.
Video consigliato:
03:57
Fever

Gram-negative Coccobacilli and Oxidase Test

Gram-negative coccobacilli are short, rod-shaped bacteria that stain pink in Gram staining. The oxidase test detects the presence of cytochrome c oxidase enzyme; a positive result indicates certain bacterial groups. Identifying oxidase-positive, gram-negative coccobacilli narrows down the possible pathogens causing the infection.
Video consigliato:
3:04
Gram-Negative Cell Walls

Differential Diagnosis of Vector-borne Febrile Illnesses

Diseases like brucellosis, malaria, relapsing fever, Rocky Mountain spotted fever, and Ebola have distinct clinical and microbiological features. Understanding their vectors, symptoms, and laboratory findings is essential for accurate diagnosis. For example, relapsing fever is caused by Borrelia species, which are spirochetes, not coccobacilli, so the microbiological findings must be carefully correlated with clinical signs.
Video consigliato:
04:07
Differential Staining