Govt Exams
Current stewardship guidelines recommend combination therapy (often with colistin or fosfomycin), strict infection control, and judicious carbapenem use to prevent further resistance escalation in CRE.
Viral tropism is determined by complementary interactions between viral attachment proteins and specific cell surface receptors. Hepatitis B, C viruses demonstrate hepatocyte tropism through receptor-specific binding.
Haemophilus species are fastidious gram-negative coccobacilli requiring both X factor (hemin) and V factor (NAD). Culture on chocolate agar provides these factors; they won't grow on regular blood agar.
The spike protein mediates receptor binding and membrane fusion. It's the most exposed surface protein and elicits the strongest neutralizing antibody response, making it the vaccine target.
Staphylococcus aureus is catalase-positive (distinguishes from streptococci) and coagulase-positive (specific identification). Beta-hemolysis results from alpha-toxin production.
Negative-sense RNA viruses must first synthesize complementary positive-sense RNA using viral RNA-dependent RNA polymerase. This positive-sense RNA serves as mRNA and template for new negative-sense genomes.
Pseudomonas aeruginosa produces alginate, a viscous polysaccharide exopolymer that forms the biofilm matrix, protecting bacteria from antibiotics and immune responses. This is characteristic of chronic respiratory infections.
Surface glycoproteins (spike proteins in coronaviruses, gp120 in HIV) mediate host cell recognition and attachment. Matrix proteins provide structural support; enzymes have catalytic roles.
PCR with specific primers targeting antibiotic resistance genes (like mecA, blaTEM) directly amplifies and identifies plasmid-encoded resistance. Other methods lack this molecular specificity.
Integration is the process by which retroviral DNA (synthesized via reverse transcriptase) becomes incorporated into host genomic DNA. This establishes persistent infection and can cause insertional mutagenesis.