Strains of Staphylococcus species that exhibit resistance to beta-lactam antibiotics are referred to as what?

Strains of Staphylococcus species that exhibit resistance to beta-lactam antibiotics are referred to as heteroresistant. This term describes a situation where a bacterial population contains both susceptible and resistant subpopulations. In the case of Staphylococcus, particularly with the well-known strain Staphylococcus aureus, heteroresistance manifests when some cells within a colony can survive exposure to beta-lactam drugs like methicillin, while most others are susceptible. This phenomenon complicates treatment options and necessitates careful microbiological testing to ensure appropriate antibiotic selection.

The other terms provided do not accurately describe this specific type of resistance. Bacteriophage group 52S refers to a particular group of viruses that infect bacteria, which is unrelated to antibiotic resistance. Cross resistance generally describes a situation where resistance to one antibiotic implies resistance to another, but it does not capture the particular nuance of heteroresistance in Staphylococcus. Lastly, plasmid altered suggests that the resistance is due to genetic changes on plasmids, which may not fully encompass the complex nature of heteroresistance seen in these strains. Thus, the term heteroresistant is the most precise in describing the resistance pattern in these Staphylococcus species.