Govt. Exams
Entrance Exams
Coxiella burnetii is highly infectious, forms spores, and is transmitted through aerosol route from infected animals.
Multiple enveloped virus families (orthomyxoviruses, paramyxoviruses, alphaviruses) utilize pH-dependent endosomal fusion for genome release into cytoplasm.
Acinetobacter baumannii forms robust biofilms on environmental surfaces and medical devices, surviving desiccation and disinfection, complicating infection control.
The HN protein of paramyxoviruses mediates both hemagglutination (receptor binding) and neuraminidase activity (sialic acid cleavage), unlike orthomyxoviruses with separate H and N proteins.
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.
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.
PCR with specific primers targeting antibiotic resistance genes (like mecA, blaTEM) directly amplifies and identifies plasmid-encoded resistance. Other methods lack this molecular specificity.
Filoviruses (Ebola, Marburg) cause hemorrhagic fevers, possess negative-sense RNA, and display characteristic helical/filamentous morphology with extreme pathogenicity.
Antigenic drift involves gradual accumulation of point mutations in viral genes (especially surface proteins), causing slight changes in viral characteristics. This is distinct from antigenic shift (reassortment in segmented viruses like influenza).
