Diversity of Viruses

Virus detection is crucial for accurately identifying diseases, especially those with specific symptoms.

Light microscopes detect cytopathic effects, such as syncytia or giant cells, in infected tissues.

Electron microscopes examine cellular components to provide detailed images of viruses.

<p>Serology involves detecting antibodies in the blood to determine the presence of viral infections.</p> Signup and view all the answers

<p>In primary cell culture, cells grow into a monolayer in a dish, and any cytopathic effects are observed.</p> Signup and view all the answers

<p>Plaques are clear zones in a cell monolayer where viruses have killed cells, indicating viral presence.</p> Signup and view all the answers

<p>Syncytia are large, multinucleated cells formed by the fusion of infected cells, often seen in viral infections.</p> Signup and view all the answers

<p>PCR amplifies viral DNA or RNA, allowing for sensitive and specific detection of viruses.</p> Signup and view all the answers

<p>Pili are short protein fibers that extend from the surface of gram-negative bacteria, serving to attach cells to surfaces and acting as virulence factors in pathogenic bacteria.</p> Signup and view all the answers

<p>Type IV pili provide 'twitching motility' to bacteria, allowing them to move across surfaces.</p> Signup and view all the answers

<p>Conjugation pili are specialized structures used by bacteria to transfer genetic material between cells, unlike other pili that primarily assist in adhesion.</p> Signup and view all the answers

<p>Bacterial flagella are used for locomotion and enable chemotaxis, allowing bacteria to move toward or away from chemical gradients.</p> Signup and view all the answers

<p>Bacterial spores are highly resistant structures that can survive extreme conditions, such as desiccation and heating, and can germinate to form vegetative cells.</p> Signup and view all the answers

<p>Vegetative cells usually die at 60°C, while bacterial spores require heating to at least 121°C for 15 minutes for destruction.</p> Signup and view all the answers

<p>Viruses are called obligate intracellular parasites because they cannot replicate on their own and must invade a host cell to reproduce and propagate.</p> Signup and view all the answers

<p>Viruses lack the machinery to generate energy or large molecules, depending entirely on their host cells for these processes.</p> Signup and view all the answers

<p>The differences in flagella structure, such as number and arrangement, can be used to classify bacterial strains and identify them under microscopy.</p> Signup and view all the answers

<p>Spores possess a tough outer coating and a highly dehydrated state, enabling them to survive extreme heat and desiccation.</p> Signup and view all the answers

<p>The portal of entry refers to the route through which an exogenous pathogen enters the host.</p> Signup and view all the answers

<p>Invasiveness is linked to virulence determinants because it affects the ability of a pathogen to spread within the host.</p> Signup and view all the answers

<p>Infectious dose is the number of microorganisms needed to initiate an infection, often determining the severity and spread of the disease.</p> Signup and view all the answers

<p>Many portals of exit from the body are the same sites as portals of entry, facilitating the cycle of infection.</p> Signup and view all the answers

<p>Energy and tissue cells are required for the host's immune response and for the pathogen's proliferation during an infection.</p> Signup and view all the answers

<p>Typhoid fever requires about 100 cells to establish an infection, which indicates that even a small number of pathogens can cause disease.</p> Signup and view all the answers

<p>When the immune system fails to respond, it can lead to uncontrolled pathogen proliferation and severe illness.</p> Signup and view all the answers

<p>Methods of transmission can affect virulence by determining how readily the pathogen spreads and infects hosts.</p> Signup and view all the answers

<p>Pathogens that have a higher infectious dose may have evolved to rely on larger quantities to successfully infect due to their robustness or the host's defenses.</p> Signup and view all the answers

<p>Understanding the sequence is critical to identifying points for intervention and prevention measures in public health.</p> Signup and view all the answers

<p>Maintaining high concentrations of the drug in the patient for sufficient time is a key strategy.</p> Signup and view all the answers

<p>Searching for new antibiotics, semi-synthetics, and synthetics is a method to develop new antimicrobial agents.</p> Signup and view all the answers

<p>Bacteriophages are viruses that infect bacteria and may be used therapeutically to target and destroy pathogenic bacteria.</p> Signup and view all the answers

<p>The two distinct life cycles of bacteriophages are the lytic and lysogenic cycles.</p> Signup and view all the answers

<p>Using specific antimicrobials is important to ensure that treatment is effective and to minimize unnecessary resistance development.</p> Signup and view all the answers

<p>Coronaviruses have single-stranded (+) sense RNA.</p> Signup and view all the answers

<p>Replicase is a polymerase enzyme that catalyzes the self-replication of single-stranded RNA.</p> Signup and view all the answers

<p>Coronaviruses have a tiny genome, around 30 Kb, compared to bacterial genomes (~5 million bp) and human genomes (3 billion).</p> Signup and view all the answers

<p>Molecular phylogeny indicates that the SARS virus is not closely related to other coronaviruses.</p> Signup and view all the answers

<p>Epidemiological studies involving PCR and sequence analysis have shown that bats harbor the SARS virus.</p> Signup and view all the answers

<p>The SARS-CoV-2 genome is approximately 30 Kb in size.</p> Signup and view all the answers

<p>Structural proteins are one of the components found in the coronavirus genome.</p> Signup and view all the answers

<p>Replicase 1B refers to one of the gene sequences involved in RNA replication in coronaviruses.</p> Signup and view all the answers

<p>The small genome size influences the virus's replication speed and mutation rate.</p> Signup and view all the answers

<p>Structural proteins are crucial for the virus's ability to enter and infect host cells.</p> Signup and view all the answers

<p>Modulating the gut microbiome can potentially prevent or treat various diseases due to its involvement in numerous physiological functions.</p> Signup and view all the answers

<p>Current trials are mainly pilot studies with small sample sizes and lack a complete understanding of the underlying mechanisms.</p> Signup and view all the answers

<p>Koch and Pasteur's definitive experiments established foundational principles in microbiology, demonstrating the role of microbes in disease.</p> Signup and view all the answers

<p>Microbiome research can enhance our understanding of disease mechanisms and host-microbe interactions, potentially identifying new disease pathways.</p> Signup and view all the answers

<p>The human microbiome serves as a complex ecosystem where microbial interactions play a vital role in overall health and disease.</p> Signup and view all the answers

<p>Understanding antibiotic resistance mechanisms helps develop new strategies to combat resistant pathogens and improve treatment efficacy.</p> Signup and view all the answers

<p>Biofilm formation enhances bacterial virulence by providing protection from the host immune system and antibiotics.</p> Signup and view all the answers

<p>A diverse microbiome is associated with better health outcomes, while reduced diversity can contribute to various diseases.</p> Signup and view all the answers

<p>Bacteria can develop antibiotic resistance through mutations that alter drug targets or by acquiring resistance genes via horizontal gene transfer.</p> Signup and view all the answers

<p>Biofilms protect bacteria from the immune response and increase resistance to antibiotics, allowing persistent infections.</p> Signup and view all the answers

<p>Emerging infectious diseases are new or previously unrecognized infections that have increased in incidence; an example is Zika virus.</p> Signup and view all the answers

<p>Microbial ecology encompasses interactions among microorganisms and their environments, influencing pathogen virulence and disease spread.</p> Signup and view all the answers

<p>Koch's postulates provide a framework for linking specific pathogens to diseases, although they have limitations in certain contexts.</p> Signup and view all the answers

<p>Bacterial mutations can lead to changes in virulence factors, allowing pathogens to adapt and survive under selective pressures.</p> Signup and view all the answers

<p>The misuse and overuse of antibiotics, along with incomplete courses of treatment, contribute to antibiotic resistance.</p> Signup and view all the answers

<p>Horizontal gene transfer allows for the exchange of resistance genes between bacteria, facilitating the rapid spread of antibiotic resistance.</p> Signup and view all the answers

<p>Biofilms protect microbes by creating a physical barrier and altering the microenvironment, making it difficult for antibiotics to penetrate.</p> Signup and view all the answers

<p>Biofilm formation often leads to chronic infections that are difficult to treat because the biofilm matrix protects bacteria from antibiotics.</p> Signup and view all the answers

<p>One challenge is the complexity of interactions among diverse microorganisms that can influence pathogen behavior and host responses.</p> Signup and view all the answers

<p>Polymicrobial diseases involve multiple microbial species working together, complicating treatment and increasing virulence.</p> Signup and view all the answers

<p>Microbial ecology studies how microorganisms interact with each other and their environments, influencing disease spread and virulence.</p> Signup and view all the answers

<p>Environmental changes can disrupt ecosystems, leading to changes in host-pathogen interactions that increase disease incidence.</p> Signup and view all the answers

<p>The microbiome maintains health by aiding digestion, regulating the immune system, and protecting against pathogens.</p> Signup and view all the answers

<p>Emerging diseases pose significant public health threats due to their potential for rapid spread and lack of effective treatments.</p> Signup and view all the answers

<p>Specific biochemical mechanisms such as toxin production and immune evasion play crucial roles in enhancing bacterial virulence by damaging host tissues and avoiding immune responses.</p> Signup and view all the answers

<p>Biofilm formation provides a protective matrix that shields bacterial communities from antibiotics and enhances their ability to survive in hostile environments.</p> Signup and view all the answers

<p>Bacteria employ mechanisms like adhesion, toxin production, and immune system evasion to establish virulence.</p> Signup and view all the answers

<p>Genetic exchange, such as through horizontal gene transfer, allows bacteria to rapidly acquire resistance genes, enabling their survival against antibiotics.</p> Signup and view all the answers

<p>Understanding microbial evolution allows researchers to identify resistance mechanisms and develop targeted treatment strategies.</p> Signup and view all the answers

<p>Changes in microbial ecology, such as environmental disturbances or shifts in host populations, can lead to new pathogens emerging or existing ones becoming more virulent.</p> Signup and view all the answers

<p>Biofilms significantly increase the risk of hospital-acquired infections by providing a reservoir for persistent pathogens resistant to treatment.</p> Signup and view all the answers

<p>Studying the small percentage of known microbes helps us understand their roles in ecosystems, health, and disease impacts.</p> Signup and view all the answers

<p>Molecular Koch's postulates provide a framework for identifying virulence factors based on genetic and molecular criteria, rather than solely relying on phenotypic characteristics.</p> Signup and view all the answers

<p>Efflux pumps are membrane proteins that actively transport antibiotics out of bacterial cells, reducing the drug concentration and allowing the bacteria to survive treatment.</p> Signup and view all the answers

<p>Understanding microbial evolution can inform public health strategies by predicting how pathogens might adapt to treatments and emerge as new threats.</p> Signup and view all the answers

<p>Bacteria use a process called quorum sensing to detect and respond to changes in population density, coordinating biofilm formation and gene expression.</p> Signup and view all the answers

<p>Antibiotic misuse, such as overprescribing or incomplete courses of treatment, creates selective pressure that promotes the survival of resistant bacterial strains.</p> Signup and view all the answers

<p>Environmental changes, such as climate change or urbanization, can disrupt ecosystems, leading to increased human exposure to pathogens and the emergence of new infectious diseases.</p> Signup and view all the answers

<p>Bacterial toxins are harmful substances produced by bacteria that can damage host tissues, disrupt cell functions, and provoke strong immune responses, thereby increasing the virulence of pathogens like Streptococcus.</p> Signup and view all the answers

<p>Antibiotic resistance occurs when bacteria evolve to resist the effects of drugs designed to kill them, making infections harder to treat and leading to increased morbidity and mortality rates.</p> Signup and view all the answers

<p>Biofilm formation allows bacteria to adhere to surfaces, protect themselves from immune responses and antibiotics, and create a microenvironment that enhances their survival and persistence in chronic infections.</p> Signup and view all the answers

<p>Factors such as genetic mutations, increased virulence due to new strains, antibiotic resistance, and environmental changes can all contribute to the emergence of infectious diseases.</p> Signup and view all the answers

<p>The microbiome, the collection of microbes living in and on the human body, plays a crucial role in inflammation, immunity, and overall health, influencing susceptibility to diseases and infections.</p> Signup and view all the answers