WASHINGTON — Sounding an alarm about the growing threat of superbugs, the Obama administration is proposing a jump in spending to fight antibiotic-resistant germs in hospitals. Infections that can withstand some of the best antibiotics already are killing more than 23,000 Americans a year, and some bacteria are becoming resistant to drugs of last resort, according to the Centers for Disease Control and Prevention.

In Tuesday’s budget, the CDC is seeking $30 million to open specialized laboratories in five parts of the country to help local hospitals more quickly diagnose and combat drug-resistant infections, said CDC director Dr. Tom Frieden.