abstract
background
bacteria
bacterial
bacterium
blue
causing
cells
chains
cocci
coccus
dangerous
disease
flora
germs
grampositive
health
illustration
infection
infections
lung
medicine
meningitis
microbes
microbiology
microbiome
microbiota
mutans
pathogen
pathogenic
pathogens
pneumococcal
pneumococci
pneumococcus
pneumonia
pneumoniae
probiotic
respirators
science
sepsis
spherical
strains
streptococcaceae
streptococcal
streptococcus
thermophilus
tract
upper
water