New Antibiotics Can Be Useful as Treatment for Community-Acquired Pneumonia

New antibiotics could expand the treatment options for community-acquired pneumonia (CAP), especially for individuals with comorbidities or the elderly, given that CAP has been very resistant to antibiotic treatments, according to the results of a study published in BioScience Trends.

The study authors evaluated a few new treatments that could be beneficial in treating antibiotic-resistant bacteria. Lefamulin, omadacycline, ceftaroline, delafloxacin have all been reported as treatment options.

Lefamulin has antimicrobial activity against common pathogens that cause community-acquired bacterial pneumonia (CABP), but can also be used to treat atypical pathogens, according to the study. Omadacycline was approved for the treatment of CABP, as well as for acute bacterial skin and skin structure infections.

Ceftaroline interferes with the cell wall and fights against most CAP pathogens; whereas delafloxacin has been approved for treatment in multiple causes of CABP and is compared to moxifloxacin.

Antimicrobials are frequently used to treat CAP including azithromycin, Augmentin (amoxicillin/clavulanic acid), levofloxacin, and third-generation cephalosporins. However, increasing resistance to antibiotic treatments, caused by bacterial gene mutations or the acquisition of drug resistance genes due to antibiotic overuse, has posed a problem, according to the study.

Streptococcus pnemoniae is the leading bacteria that causes CAP, however, atypical bacteria, such as Mycoplasma pnemoniae and Chlamydia pnemoniae, could become more common, according to the study.

Streptococcus pnemoniae has been reported to be resistant to 1 or more antibiotics during treatment in approximately one-third of cases. It is mainly resistant to macrolides, such as azithromycin. According to the report, Streptococcus pnemoniae is averagely susceptible to azithromycin by 3.4%, erythromycin by 1.9%, tetracycline by 8.8%, and penicillin by 15.7%.

Streptococcus pnemoniae is susceptible to vancomycin, ceftaroline, and levofloxacin.

Individuals who are elderly or who have comorbidities are more likely to become infected with CAP, according to the study.

ESKAPE (Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, and Enterobacter species) pathogens, which also causes CAP, display resistance to macrolides, fluoroquinolones, β-lactams, and third- and fourth-generation cephalosporins.

Staphylococcus aureus, a typical ESKAPE pathogen, is susceptible to erythromycin by 18%, ciprofloxacin by 28%, and levofloxacin by 23.4%.

Atypical bacteria have a high level of resistance to macrolides. Fluoroquinolones or tetracyclines should be considered as alternatives, according to the study.

The current treatment guide varies, but it is widely suggested that treatment is based off the presence or absence of underlying disease and severity of CAP.

The Infectious Diseases Society of America/American Thoracic Society recommends that the first line of treatment for drug-resistant Streptococcus pnemoniae for individuals without comorbidities is amoxicillin or doxycycline.

For individuals with chronic diseases, levofloxacin, moxifloxacin, or a combination of β-lactams and macrolides are recommended.

Out of 100,000 adult individuals in the United States, 5832 individuals with chronic obstructive pulmonary disease contracted CAP. Other comorbidities include, but are not limited to, asthma, bronchiectasis, coronary heart disease, and cardiac failure.

These individuals are also more likely to experience more complication and death.

In the United States, nearly 50% of individuals with CAP who are hospitalized are over 75 years of age.

CAP can cause a fever, cough, expectoration, chest pains, and dyspnea. Approximately 68% of adult individuals with CAP are admitted to the hospital, the investigators said.

Reference

Shen L, Wang L, Lui C, Shi S, Takahashi T, Wang T. Community-acquired pneumonia: trends in and research on drug resistance and advances in new antibiotics. Biosci Trends. 2021;doi:10.5582/bst.2021.01342