Bacteria can become resistant to penicillin by modifying enzymes that make the cell wall. Some bacteria, including Streptococcus phenominae, have developed resistance to β-lactams through modification of their penicillin binding proteins (or PBPs), which make up the active site of transpeptidase enzymes.

Bacteria resistant to antibiotics For example, Staphylococcus aureus (‘golden staph’ or MRSA) and Neisseria gonorrhoeae (the cause of gonorrhoea) are now almost always resistant to benzyl penicillin.

Mechanisms of Antibiotic Resistance Some bacteria are naturally resistant due to an unusually impermeable cell membrane or a lack of the target that the antibiotic attacks. Other bacteria are capable of producing enzymes that can inactivate antibiotics upon contact.

Bacteria, not humans or animals, become antibiotic-resistant. These bacteria may infect humans and animals, and the infections they cause are harder to treat than those caused by non-resistant bacteria. Antibiotic resistance leads to higher medical costs, prolonged hospital stays, and increased mortality.

How are MDROs treated? MDROs are hard to treat because they are resistant to many common antibiotics. But, a few antibiotics can be used. Your doctor will decide which antibiotics to prescribe based on the germ and location of the infection.

MDR infections pose a real threat to immunocompromised patients, causing severe infections with poor outcomes. The increase in infections caused by gram-negative and gram-positive resistant bacteria is concerning for the success of empiric treatment of febrile neutropenia.

Multidrug resistance in bacteria occurs by the accumulation, on resistance (R) plasmids or transposons, of genes, with each coding for resistance to a specific agent, and/or by the action of multidrug efflux pumps, each of which can pump out more than one drug type.

Common examples of these organisms include:

• MRSA – Methicillin/oxacillin-resistant Staphylococcus aureus.
• VRE – Vancomycin-resistant enterococci.
• ESBLs – Extended-spectrum beta-lactamases (which are resistant to cephalosporins and monobactams)
• PRSP – Penicillin-resistant Streptococcus pneumoniae.

What is a multidrug resistant organism (MDRO)?

• Urinary tract infections (UTIs)
• Pneumonia.
• Blood infections.
• Wound infections.

Common multidrug-resistant organisms are usually bacteria:

• Vancomycin-Resistant Enterococci (VRE)
• Methicillin-resistant Staphylococcus aureus (MRSA)
• Extended-spectrum β-lactamase (ESBLs) producing Gram-negative bacteria.
• Klebsiella pneumoniae carbapenemase (KPC) producing Gram-negatives.

Meticulous hand hygiene, environmental disinfection, chlorhexidine baths, and other infection control measures can interrupt spread of MDRO. Antimicrobial stewardship is an essential tool for improving quality of care and reducing selective pressure that promotes emergence of multidrug resistance.

Multidrug-resistant organisms can cause infections in almost any part of the body, including: Bloodstream. Lungs….What are some risk factors for MDRO infections?

• An existing severe illness.
• An underlying disease or condition such as diabetes, chronic kidney disease, or skin lesions.
• Previous prolonged use of antibiotics.

MDRO Prevention

1. Clean their hands with soap and water or alcohol-based hand rub before and after contact with each patient.
2. Clean high-touch surfaces with a disinfectant that kills MRSA and other bacteria and viruses often found in health care settings.

MDROs can be difficult to treat since many antibiotics won’t work to treat them. Examples of MDROs include: Methicillin resistant Staphylococcus aureus (MRSA) Resistant Acinetobacter.

MDROs or multi-drug resistant organisms are germs, mostly bacteria, which over time have adapted to antibiotics, making antibiotics less effective or not effective at all. In other words, this means the antibiotics used to treat these germs don’t work well or don’t work at all.

Airborne precautions are required to protect against airborne transmission of infectious agents. Diseases requiring airborne precautions include, but are not limited to: Measles, Severe Acute Respiratory Syndrome (SARS), Varicella (chickenpox), and Mycobacterium tuberculosis.

Three things are necessary for an infection to occur:

• Source: Places where infectious agents (germs) live (e.g., sinks, surfaces, human skin)
• Susceptible Person with a way for germs to enter the body.
• Transmission: a way germs are moved to the susceptible persont.