Amoxicillin is a newer version of penicillin that covers more types of bacteria. Amoxicillin was created by modifying the original chemical structure of penicillin to make it more potent. Both amoxicillin and penicillin cover Streptococcal bacteria.

Bacteria resistant to antibiotics

• methicillin-resistant Staphylococcus aureus (MRSA)
• vancomycin-resistant Enterococcus (VRE)
• multi-drug-resistant Mycobacterium tuberculosis (MDR-TB)
• carbapenem-resistant Enterobacteriaceae (CRE) gut bacteria.

Examples of bacteria that are resistant to antibiotics include methicillin-resistant Staphylococcus aureus (MRSA), penicillin-resistant Enterococcus, and multidrug-resistant Mycobacterium tuberculosis (MDR-TB), which is resistant to two tuberculosis drugs, isoniazid and rifampicin.

This medication may be taken with or without food. However, penicillin is best absorbed when taken on an empty stomach (1 hour before or 2 hours after meals). The dosage is based on your medical condition and response to treatment. For the best effect, take this antibiotic at evenly spaced times.

Here is a list of some of the leading antimicrobial drug-resistant organisms NIAID is researching.

• Mycobacterium tuberculosis. The bacterium that causes tuberculosis (TB)
• C. difficile.
• VRE. (Vancomycin-resistant Enterococci)
• MRSA. (Methicillin-resistant Staphylococcus aureus)
• Neisseria gonorrhoea.
• CRE.

Antibiotics begin to work right after you start taking them. However, you might not feel better for two to three days.

You’ll usually take phenoxymethylpenicillin 4 times a day to treat an infection. In most cases you’ll start to feel better in a few days.