Видео

Ok I give up. TELL ME! 🤦🏻‍♀️

Entamoeba histolystica

Option D

Osteosarcoma?

Option C (Ewing’s Sarcoma)

Amphotericin b

Ewing's?

Im assuming *option A* Note :This is from a no medical background. Im guessing based on the urine problem.

B?

ANS: C) Plesiomonas shigelloides Plesiomonas shigelloides is commonly associated with gastroenteritis linked to the consumption of seafood. It is distinct within the Enterobacteriaceae family for being oxidase positive and lactose non-fermenting. These characteristics help differentiate it from other more common enterobacteria such as Escherichia coli, Salmonella, and Shigella, which are oxidase negative.

ANS: B) Shigella dysenteriae Shigella dysenteriae fits the profile provided, being non-motile and unable to ferment lactose or produce gas or H2S. These characteristics distinguish Shigella from other Enterobacteriaceae such as Salmonella, which can produce H2S, and Escherichia coli, which ferments lactose.

ANS: C) Proteus mirabilis Proteus mirabilis is known for its characteristic swarming motility on agar plates and strong urease activity.

ANS: A) Indole test negative Klebsiella pneumoniae is known for its mucoid colonies due to the polysaccharide capsule and is non-motile. It is also characteristic for Klebsiella to be negative for the Indole test, which differentiates it from other Enterobacteriaceae like Escherichia coli which is indole positive.

ANS: A) Indole test positive Escherichia coli is known for its ability to ferment lactose and produce a distinctive metallic sheen on EMB agar. It is also positive for the Indole test, which detects the ability to produce indole from tryptophan.

ANS: B) The organism produces a heat-stable toxin causing emetic symptoms. Explanation: The scenario describes symptoms typical of Bacillus cereus food poisoning linked to rice dishes, where the rapid onset of nausea and vomiting is caused by a heat-stable emetic toxin produced by Bacillus cereus. This toxin is not deactivated by cooking, making it a common culprit in foodborne illnesses linked to starchy foods like rice that are left at room temperature. Note: The Diarrheal Toxin is a heat-labile toxin leading to increased cAMP levels, causing watery diarrhea; associated with meat or vegetable dishes.

ANS: B Explanation: The patient’s symptoms and occupational exposure suggest inhalation anthrax (“woolsorter’s disease,”), caused by Bacillus anthracis. Bacillus anthracis is known for forming large, non-hemolytic, non-motile, gray to white colonies with a characteristic “Medusa-head” formation on culture media, which is a critical characteristic for differentiating it from other Bacillus species, such as Bacillus cereus, which is motile and Weakly beta hemolytic. Note: The most common form of anthrax infection is Cutaneous Anthrax characterized by a papule that progresses to a vesicle and finally to a necrotic ulcer with a central black eschar.

ANS: B) Actinomyces israelii Explanation: Actinomyces israelii is known for causing chronic infections characterized by the formation of sulfur granules, which are aggregates of organisms seen in purulent discharge from sinus tracts. This type of infection typically arises in association with poor dental hygiene and can lead to osteomyelitis of the mandible or maxilla. The presence of sulfur granules is a hallmark of Actinomyces infections, differentiating it from other listed microorganisms.

ANS: C) Nocardia species Explanation: The clinical presentation, along with the identification of gram-positive, weakly acid-fast, filamentous bacteria in the sputum culture, strongly suggests a Nocardia infection. Nocardia typically presents with pulmonary disease characterized by cavitation in immunocompromised hosts or those with underlying lung disease, differentiating it from other potential pathogens listed.

ANS: A) Tuberculoid leprosy Explanation: The clinical presentation of hypopigmented, anesthetic patches, and thickened nerves, along with the presence of few acid-fast bacilli in the skin biopsy, are characteristic of tuberculoid leprosy. This form of the disease exhibits a strong cell-mediated immune response that contains the spread of the bacilli, resulting in fewer bacteria and localized symptoms.

ANS: C) Mycobacterium avium complex Explanation: In an HIV-positive patient with a very low CD4 count presenting with systemic symptoms and evidence of acid-fast bacilli in lymph node biopsies, the most likely culprit is Mycobacterium avium complex. This pathogen commonly causes disseminated disease in severely immunocompromised patients, unlike Mycobacterium tuberculosis, which typically presents with pulmonary symptoms.

ANS: B) Erysipelothrix rhusiopathiae Explanation: Erysipelothrix rhusiopathiae is characterized by gram-positive rods that can form long filaments, particularly in cutaneous infections. It is a common pathogen in individuals who handle fish and meat, which matches the occupational exposure of the fisherman. The clinical presentation of a localized erythematous lesion that is resistant to topical treatment is typical of an erysipeloid infection caused by Erysipelothrix rhusiopathiae.

ANS: C) Motility at room temperature (25 degrees Celsius) Explanation: Listeria monocytogenes exhibits characteristic motility at room temperatures due to its flagella, which are expressed at 22 to 28 degrees Celsius. This motility is observed as a tumbling movement in liquid media. The organism’s ability to grow well at refrigeration temperatures and its catalase-positive reaction also support the diagnosis but the distinct motility at lower temperatures is more indicative.

ANS: D) Black colonies on cystine-tellurite blood agar Explanation: Corynebacterium diphtheriae typically forms black colonies on cystine-tellurite blood agar due to its ability to reduce tellurite. This medium is specifically used to isolate and identify this bacterium, which is consistent with the presentation of a pseudomembrane in a patient with suspected diphtheria. The other options are not characteristic of Corynebacterium diphtheriae; for example, it does not grow on MacConkey agar, which is selective for Gram-negative bacteria.

Correct answer A: Explanation: Nonsteroidal anti-inflammatory drugs (NSAIDs) such as ibuprofen decrease the production of prostaglandins and thromboxanes, which mediates their anti-inflammatory, analgesic, and antipyretic effects. Chronic NSAID use can decrease protective prostaglandins, specifically PGE2, found in the gastric mucosa. This prostaglandin protects the stomach from the low gastric pH needed for digestion. Chronic NSAID use, as well as one-time large doses, can lead to peptic ulcer disease. The damage to the gastric mucosa caused by chronic NSAID use can also increase the risk of colonization of the gastric mucosa by H. pylori, as seen in this patient.

Correct answer: B Staphylococcus aureus. Explanation: The description of the colonies growing as yellow on mannitol salt agar, along with being catalase and coagulase positive, points towards Staphylococcus aureus. This bacterium is a common cause of osteomyelitis, particularly following trauma or in the setting of an open fracture, which provides a route of entry for the bacteria. Staphylococcus epidermidis, another differential option, typically produces pink colonies on mannitol salt agar, is coagulase negative, and urease positive, distinguishing it from Staphylococcus aureus.

Correct Answer: D Streptococcus agalactiae is the most common cause of septicemia and meningitis in newborns. The laboratory findings of large colonies with small beta-hemolytic zones, positive CAMP test (enlarges (haemolysis area formed by Staphylococcus aureus confirming the presence of GBS), and positive hippurate hydrolysis are characteristic of S. agalactiae. Note that S. pyogenes would give small colonies and large zones of beta hemolysis.

Correct answer: C Viridans streptococci are optochin-negative and also Deoxycholate negative. This helps differentiate them from Streptococcus pneumoniae which is optochin-positive and Deoxycholate positive.

Correct answer: C Explanation: ASO test is not suitable for skin infections because Streptolysin O is inactivated by oxygen and skin cholesterol. Anti-DNase B test is used for skin infections.

Correct answer: C Streptolysin S is oxygen-stable and non-immunogenic.

Correct answer: C. They grow on 6.5% NaCl at 10 to 45 degrees Celsius. This differentiates them from other Group D streptococci which do not grow on 6.5% NaCl.