Microbiology - NCLEX-PN

Neisseria gonorrhoeae is a Gram negative coccus bacterium that generally presents as a diplococcus (in pairs of cocci).

_Staphyloccocus aureus are Gram positive cocci. Chlamydia trachomatis and Rikettsia prowazekii are both classified as Gram negative rods and Neisseria meningitidis are Gram negative cocci.

All of the bacteria listed are Gram positive except Salmonella, which is a Gram negative facultative rod.

Vibrio cholerae is classified as Gram negative facultative rods. This bacteria is the most well known amongst the Vibrio species as it's the cause of cholera, which produces a toxin that causes very severe diarrhea.

Bacteria or any other microbes that feed on dead matter are termed saprophytes. Thermophilic microbes thrive in heated environments, halophiles such as _Vibrio parahaemolyticu_s prefer salt water, and archaebacteria are a group of bacteria found in high heat, high salt content locations such as sewage treatment plants and are able to tolerate many extreme habitats.

E. coli is a Gram negative rod. It's a lactose fermenting bacteria commonly implicated in urinary tract infections and less frequently in gastroenteritis.

Staphylococcus species are Gram positive, catalase positive cocci. The most famous member of this bacterial species, Staphylococcus aureus, is commonly implicated in skin infections, upper respiratory infections, and gastroenteritis (food poisoning).

The question requires the knowledge that Escherichia coli is a facultative, Gram negative, lactose fermenting bacteria. EMB (eosin methylene blue), or Mac (MacConkey) media is superior for isolating Escherichia coli because it is both selective and differential. Nutrient agar is neither selective nor differential. Selenium enriched media would not help identify this bacteria because Escherichia coli does not require this supplemented media to grow. Phenethyl alcohol can be used to select for anaerobic bacteria, which is of no utility in this situation.

Genital warts is caused by human papillomavirus. All other sexually transmitted infection is correctly matched with its causative agent.

The question stem describes bubonic plague which is caused by Yersinia pestis. Staphylococcus aureus causes skin infections, toxic shock, and food poisoning. _Bacillus anthraci_s causes anthrax, which is similar to plague, but does not cause buboes. Borrelia burgdorferi causes lyme disease., which presents as rash and arthralgia.

The colon is anaerobic and the bladder is aerobic. This fact explains why E. coli normally lives in an anaerobic environment, but can also survive aerobically. Facultative anaerobes normally live in anaerobic conditions but can adapt to aerobic conditions. Microaerophiles describes bacteria that are obligate aerobes, but are poisoned by high levels of oxygen and thus require specific oxygen levels to grow.

Bacteria are classified as either Gram positive or Gram negative. Gram positive bacteria stain purple because of their thick peptidoglycan cell wall. Staph and Strep groups are both Gram positive. Bacteria can then be organized based on their shape. Cocci are circular while bacilli are rectangular in shape. Staph grows in clusters.

While Proteus penneri and Proteus vulgaris do cause opportunistic infections in a small percentage of people, 90% of Proteus infections in humans are caused by Proteus mirabilis.

_Proteus myxofaciens is only found in insect hosts and does not infect humans.

Proteus mirabilis is a Gram-negative, facultatively anaerobic, rod-shaped (bacillus) bacteria. It produces large amounts of the enzyme urease, which is able to hydrolyze urea to ammonia, causing the distinctively high pH seen in the urine of individuals with a P. mirabilis infection.

Orchitis due to mumps has decreased significantly due to vaccination, but it is still a significant risk in unvaccinated individuals. Mumps-related orchitis can result in testicular failure later in life. None of the other microbial infections listed have an association with orchitis.

Individuals with hepatitis C have a much higher incidence of development of type II diabetes. This is thought to be due to increased levels of tumor necrosis factor (TNF)-alpha, which leads to insulin resistance. Gaucher's disease is a hereditary disorder of glucosylceramide accumulation that can affect the liver but is not caused by hepatitis C virus. Wasting syndrome is a general term for individuals who experience unintentional weight loss due to a disease such as cancer. Fabry disease is a rare liposomal storage disorder unrelated to any viral infection.

This question requires the student to distinguish between the rashes that are common in children; specifically those that may be present due to fear of immunizations. Measles begins with Koplik's spot in the mouth. Then the rash first appears on the forehead. Rubella first appears on the trunk, then spreads throughout the body. Chicken pox manifests as fluid-filled vesicles. Smallpox appears as blister-like lesions and this disease has been eradicated for a few decades.

All forms of warts are caused by the virus HPV, or human papillomavirus. In addition, HPV is the cause of a variety of dysplasias, including cervical dysplasia, vulvar dysplasia, and oropharyngeal cancer. None of the other viruses listed are associated with warts of any kind.

While all of the strains of HPV may cause condylomata acuminata, 90% of all cases of genital warts are caused by just two strains: 6 and 11.

Human papillomavirus has been associated with several forms of cancer, including cancers of the cervix, vulva, anus, and oropharynx. It is also associated with penile and vaginal dysplasias.