Micro - Chlamydiae And Rickettsiae

Trachoma, an ocular disease affecting children and a possible cause of blindness, is caused by the bacteria Chlamydiae. This bacteria is responsible for the infection and inflammation of the conjunctiva, which can lead to scarring and ultimately result in blindness if left untreated. Therefore, Chlamydiae is the correct answer in this case.

Mycoplasma pneumoniae is positive for cold agglutinins, which means that it can cause the clumping of red blood cells at lower temperatures. On the other hand, Chlamydophila pneumoniae (formerly known as Chlamydia pneumoniae) does not produce cold agglutinins. Therefore, the statement is true as it correctly distinguishes between the two bacteria based on their cold agglutinin test results.

Pt. presents with R. prowazekii infection, which is a bacterium that causes epidemic typhus. Therefore, the patient may develop typhus fever as a result of the infection. Lyme disease is caused by Borrelia burgdorferi, not R. prowazekii. Q fever is caused by Coxiella burnetii, and rickettsia refers to a group of bacteria including R. prowazekii, but it does not specifically indicate the disease that may develop.

Rickettsia and Chlamydia are both intracellular bacteria that are unable to produce ATP and amino acids on their own. They rely on their host cells to provide these essential nutrients for their survival and replication. This makes them auxotrophic bacteria. Mycoplasma, on the other hand, is capable of producing its own ATP and amino acids, so it is not auxotrophic. Therefore, the correct answer is A & B.

Chlamydiae have LPS (lipopolysaccharide) in their membranes and cell wall. LPS is a component found in the outer membrane of Gram-negative bacteria, which helps protect the cell and plays a role in immune recognition. This feature distinguishes chlamydiae from other options listed, as they do not contain murein (a component of bacterial cell walls), mycolic acid (found in the cell walls of mycobacteria), or have no cytoplasmic membrane.

A reticulate body is a developmental form of rickettsia that replicates by binary fission. This means that it is a stage in the life cycle of rickettsia where the organism divides into two identical daughter cells. This process allows for the rapid multiplication and spread of the infectious agent. Rickettsia is a type of bacteria that is known to cause various diseases in humans, such as Rocky Mountain spotted fever and typhus.

The correct answer, "type III secretion system," describes rickettsia's ability to infect endothelial cells. This system allows rickettsia to inject effector proteins directly into the host cell, enabling them to manipulate the cellular machinery and establish infection. This mechanism is crucial for rickettsia to invade and survive within endothelial cells, which are a primary target for these bacteria. By utilizing the type III secretion system, rickettsia can evade the host immune response and cause disease.

Q fever does not need a living vector for transmission. Q fever is caused by the bacterium Coxiella burnetii, which can survive in the environment for long periods of time. It is primarily transmitted to humans through inhalation of contaminated dust particles, such as those from animal feces, urine, or birth products. Unlike the other options listed, Q fever does not require a living vector, such as ticks or fleas, for its transmission.

Both chlamydiae and rickettsiae exhibit biphasic morphology. This means that they have two distinct forms in their life cycle - an infectious, non-replicating form called elementary body (EB) and a replicating form called reticulate body (RB). The EB form is small, dense, and resistant to environmental conditions, allowing for transmission between hosts. Once inside the host cell, the EB transforms into the RB form, which is larger and metabolically active, allowing for replication and multiplication within the host cell. This biphasic morphology is a common characteristic shared by both chlamydiae and rickettsiae.

Rickettsia, after being inoculated by a tick bite, attaches to the cell membrane of the vascular endothelium. This allows the bacteria to establish a foothold and invade the host's cells. By attaching to the cell membrane, Rickettsia can avoid being engulfed by cells and multiply in the lumen of the blood vessels. This attachment also facilitates dissemination via the lymphatic system, allowing the bacteria to spread throughout the host's body.

The correct answer is A & C, which means that both the direct fluorescent assay and nucleic amplification of urine can sufficiently diagnose C. trachomatis. The direct fluorescent assay is a diagnostic method that uses fluorescently labeled antibodies to detect the presence of C. trachomatis antigens. Nucleic amplification of urine involves amplifying and detecting specific DNA or RNA sequences of C. trachomatis in urine samples. These two methods are effective in diagnosing C. trachomatis infection.

Lymphogranuloma venereum (LGV) is a sexually transmitted infection caused by the bacterium Chlamydia trachomatis. It is characterized by the formation of genital ulcers and swollen lymph nodes in the groin area. LGV can coexist with N. gonorrhea infection, meaning that a person infected with LGV may also have a concurrent infection with N. gonorrhea. This co-infection can complicate the diagnosis and treatment of both infections.

Doxycycline is the drug of choice for rickettsial infections because it is a broad-spectrum antibiotic that is effective against the bacteria that cause these infections. It is a tetracycline antibiotic and has been shown to be highly effective in treating rickettsial infections such as Rocky Mountain spotted fever and typhus. Doxycycline works by inhibiting the growth and replication of the bacteria, thereby helping to eliminate the infection. It is well-tolerated and has a good safety profile, making it an ideal choice for the treatment of rickettsial infections.

An elementary body is a developmental form of Rickettsia that forms fused inclusions, except for C. pneumonia. This means that when Rickettsia is in the elementary body form, it can form clusters or groups within host cells, except in the case of C. pneumonia. This characteristic helps differentiate C. pneumonia from other types of Rickettsia.

Herpes-like lesions are most likely due to LGV biovariant. This is because LGV (Lymphogranuloma venereum) is a sexually transmitted infection caused by the bacteria Chlamydia trachomatis. It primarily affects the lymph nodes and can cause genital ulcers or sores that resemble herpes. The other options, C. pneumoniae and Rickettsia, are not typically associated with causing herpes-like lesions.

Erythromycin is the best drug therapy in this case because it is considered safe to use during pregnancy. Both azithromycin and doxycycline are contraindicated in pregnancy as they can potentially harm the developing fetus. Erythromycin, on the other hand, is commonly used to treat various infections during pregnancy and is considered safe for both the mother and the baby. The duration of therapy may vary depending on the specific condition and severity of the infection.

Patients with coronary artery disease may have a previous C. pneumoniae infection. This is because C. pneumoniae is a common cause of respiratory infections and has been associated with the development of atherosclerosis and coronary artery disease. It is believed that the bacteria may directly infect vascular cells and contribute to the development of plaques in the arteries. Therefore, a previous C. pneumoniae infection may be expected in a patient with coronary artery disease.

The correct answer is cell mediated host response to serovars. C. trachomatis is an intracellular bacterium that causes damage through the host's immune response. The immune response involves the activation of T cells, specifically CD4+ T cells, which release cytokines and chemokines to recruit other immune cells to the site of infection. This cell-mediated response leads to inflammation and tissue damage, which can result in various clinical manifestations depending on the serovar involved.

C. Pneumoniae is the correct answer because it is a bacteria known to infect cells involved in atherogenesis. Atherogenesis refers to the formation of atherosclerosis, which is the buildup of plaque in the arteries. C. Pneumoniae has been found in atherosclerotic plaques and is believed to contribute to the development and progression of atherosclerosis. This bacteria can infect endothelial cells, smooth muscle cells, and macrophages, leading to inflammation and the formation of plaques.

Chlamydiae obtain nutrients through straw-like appendages similar to a type III secretion system. This means that they use these appendages to extract nutrients from host cells by creating a channel through which they can directly access the host's resources. This method allows Chlamydiae to acquire the necessary nutrients for their survival and replication.

The presence of a rash would rule out Q fever because Q fever is a bacterial infection caused by Coxiella burnetii, which does not typically cause a rash. Common symptoms of Q fever include fever, fatigue, muscle aches, and headache, but a rash is not typically associated with this condition. Therefore, the presence of a rash would indicate a different underlying cause for the symptoms being experienced.

Chlamydia pneumonia linked to CAD while rickettsia have tropism for vascular endothelial cells

During the persistence phase, Chlamydia bacteria produce protease enzymes that help in delaying cell death. This allows the bacteria to survive and persist within the host for a longer period of time. The protease enzymes break down proteins within the host's cells, preventing the cells from undergoing programmed cell death or apoptosis. By delaying cell death, Chlamydia can continue to replicate and cause infection without being eliminated by the host's immune system.

Rickettsia can be cleared by strong host defense, meaning that a strong immune response from the host can effectively eliminate the infection caused by Rickettsia. This is in contrast to Chlamydia, which is known to establish chronic infections and is not easily cleared by the host's immune system.

Both E. ewingii and Anaplasma phagocytophilum infect neutrophils. E. ewingii is a tick-borne bacterium that causes ewingii ehrlichiosis, a disease characterized by fever, muscle aches, and headache. Anaplasma phagocytophilum is also a tick-borne bacterium that causes anaplasmosis, which leads to symptoms like fever, chills, headache, and muscle aches. Therefore, the correct answer is B & C.