Microbiology & Epidemiology

* Bacteria can be cultured and grown in various artificial culture media, such as nutrient broth, agar plates, or other specific media formulations. Bacteria can metabolize and utilize the nutrients provided in these synthetic culture media to grow and reproduce. * Fungi can also be cultured in artificial media, such as potato dextrose agar, Sabouraud dextrose agar, or other specialized fungal growth media. Fungi can utilize the organic compounds and nutrients present in these synthetic media to support their growth and development. * Viruses, on the other hand, are obligate intracellular parasites and cannot be directly cultured in artificial or synthetic media. Viruses require living host cells to replicate and propagate, as they lack the necessary machinery for autonomous growth and reproduction.

Statement 1 is correct. Pneumococcal Conjugate Vaccines (PCVs) are effective in preventing several serious diseases caused by Streptococcus pneumoniae bacteria. This includes pneumonia, meningitis (inflammation of the meninges surrounding the brain and spinal cord), and sepsis (a life-threatening blood infection). Statement 2 is also correct. The growing prevalence of antibiotic-resistant strains of Streptococcus pneumoniae is a major concern. PCV vaccination helps reduce dependence on antibiotics, particularly for these resistant strains. This lowers the risk of antibiotic overuse and emergence of further resistance. Statement 3 is incorrect. While most people experience no serious side effects with PCV vaccines, there can be mild reactions like redness, swelling, or soreness at the injection site. Serious allergic reactions are rare.

Option A is correct. Both Hepatitis B virus and HIV (Human Immunodeficiency Virus) can be transmitted through blood-to-blood contact, sexual contact, and from mother to child during childbirth. Option B is incorrect. Unlike Hepatitis C, there is a vaccine available for Hepatitis B. The Hepatitis B vaccine is highly effective in preventing Hepatitis B virus infection. Option C is correct. According to global health statistics, the number of people infected with Hepatitis B and C viruses combined is indeed several times more than those infected with HIV. Option D is correct. Many individuals infected with Hepatitis B and C viruses may not show any symptoms for years or even decades. This is known as chronic hepatitis, and it can lead to severe liver damage if left untreated.

Statement 1 is incorrect. While genetic factors can contribute to susceptibility to infections, they are not directly related to the occurrence of multi-drug resistance in microbial pathogens. Statement 2 is correct. Incorrect use of antibiotics, including taking incorrect doses or not completing the full course of treatment, can contribute to the development of drug resistance in microbial pathogens. Statement 3 is correct. The widespread use of antibiotics in livestock farming can lead to the development of drug-resistant pathogens that can affect both animals and humans. Statement 4 is incorrect. While individuals with chronic diseases may be more susceptible to infections, this factor is not directly related to the occurrence of multi-drug resistance in microbial pathogens.

All of the listed factors - birds, dust blowing, rain, and wind blowing - can contribute to the spread of plant diseases Statement 1 is correct: Birds can act as vectors, carrying and spreading plant pathogens from one location to another through their feathers, feet, or droppings. Statement 2 is correct: Dust and soil particles blown by the wind can carry and spread plant diseases, especially fungal spores and bacterial cells. Statement 3 is correct: Rain can splash and disperse plant pathogens, such as fungi and bacteria, from the soil or infected plant parts to uninfected plants. Statement 4 is correct: Wind can transport and spread airborne plant pathogens, such as fungal spores and bacterial cells, over long distances.

Statement 1 is correct: The Zika virus is primarily transmitted by the Aedes aegypti mosquito, which is the same mosquito that transmits the dengue virus in tropical and subtropical regions. Statement 2 is correct: While Zika virus is primarily transmitted through mosquito bites, the virus can also be transmitted from person to person through sexual contact. Therefore, both the statements 1 and 2 are correct.

Statement 1 is correct: Viruses that infect bacteria are known as bacteriophages or phages. These viruses use bacterial cells as hosts to replicate and propagate. Statement 2 is correct: Certain viruses, called mycoviruses, can infect and replicate within fungal cells, using them as hosts. Statement 3 is correct: Viruses that infect plants are known as plant viruses. They can hijack the cellular machinery of plant cells to replicate and spread within the plant. Hence, option D is the correct answer.

Guinea, Sierra Leone, and Liberia were in the news for the outbreak of the Ebola virus. The most widespread outbreak of the Ebola virus disease began in 2013 and continued until 2016, causing major loss of life and socio-economic disruption in the West African region, mainly in the countries of Guinea, Liberia, and Sierra Leone.
The first cases were recorded in Guinea in December 2013. Later, the disease spread to neighboring Liberia and Sierra Leone. Therefore, option B is the correct answer.

Influenza (H1N1) virus is a subtype of influenza A virus that was the most common cause of human influenza (flu) in 2009 and is associated with the 1918 outbreak known as the Spanish Flu. It is an orthomyxovirus that contains the glycoproteins haemagglutinin and neuraminidase. For this reason, they are described as H1N1, H1N2 etc., depending on the type of H or N antigens they express with metabolic synergy. - Haemagglutinin causes red blood cells to clump together and binds the virus to the infected cell.
- Neuraminidase is a type of glycoside hydrolase enzyme which helps to move the virus particles through the infected cell and assist in budding from the host cells. In June 2009, the World Health Organization (WHO) declared the new strain of swine-origin H1N1 as a pandemic. This strain is often called swine flu by the public media.

Statement 1 is incorrect: The Government introduced the Pentavalent vaccine, which also fights against Diphtheria. This implies that Diphtheria is still prevalent. Statement 2 is incorrect: Chickenpox is still widespread among the population. Statement 3 is correct: Smallpox has been eradicated from India. India declared itself free of smallpox in 1979.