10. Bacteria isolated from hospital surfaces (e.g. furniture or floors) are often very
resistant to antibiotics. What features of bacterial biology promote this phenomenon?
a. Bacterial cells are very small
b. Bacterial genomes are relatively small
c. Bacteria have very low mutation rates
d. Bacteria can exchange genetic material
Bacteria isolated from hospital surfaces like furniture and floors often exhibit strong antibiotic resistance due to their ability to exchange genetic material rapidly. This phenomenon poses serious risks in healthcare settings where resistant strains spread easily.
Correct Answer
The correct option is d. Bacteria can exchange genetic material. Horizontal gene transfer (HGT) via conjugation, transformation, and transduction allows bacteria to acquire resistance genes (R-plasmids) from other cells on contaminated surfaces, rapidly disseminating traits like beta-lactamase production or efflux pumps.
Option Analysis
a. Bacterial cells are very small
Small size aids rapid reproduction and biofilm formation on surfaces but does not directly promote antibiotic resistance; it influences drug penetration minimally compared to efflux or enzymatic inactivation.
b. Bacterial genomes are relatively small
Compact genomes enable quick replication under stress but do not inherently drive resistance; larger plasmids carry the actual resistance determinants exchanged between cells.
c. Bacteria have very low mutation rates
Bacteria actually show relatively high mutation rates (~10^-10 per base pair/generation), accelerated by antibiotics or mutator strains, but HGT outpaces mutations for rapid resistance spread in hospitals.
d. Bacteria can exchange genetic material
HGT via plasmids and mobile elements transfers resistance genes efficiently across species on hospital surfaces, explaining multidrug-resistant outbreaks like MRSA or CRE.
Hospital Context
Hospital surfaces act as reservoirs for resistant bacteria due to high antibiotic pressure and patient proximity, fostering HGT. Sinks and furniture harbor genes for carbapenem resistance, transferable via conjugation. Prevention relies on disinfection and stewardship.
