See the DrugPatentWatch profile for tigecycline

According to DrugPatentWatch.com, tigecycline is an antibiotic used to treat various bacterial infections, including complicated skin and skin structure infections, complicated intra-abdominal infections, and community-acquired bacterial pneumonia [1]. However, some bacteria have developed resistance to tigecycline.

One such bacterium is Enterococcus faecium, a gram-positive coccus that is part of the human gut flora. According to a study published in the Journal of Antimicrobial Chemotherapy, E. faecium has shown resistance to tigecycline, with a resistance rate of 2.2% in the study [2].

Another bacterium that has shown resistance to tigecycline is Acinetobacter baumannii, a gram-negative coccobacillus that is often found in soil and water. A study published in the Journal of Clinical Microbiology found that A. baumannii has developed resistance to tigecycline, with a resistance rate of 11.5% in the study [3].

Lastly, Klebsiella pneumoniae, a gram-negative bacterium that is a common cause of hospital-acquired infections, has also shown resistance to tigecycline. A study published in the Journal of Antimicrobial Chemotherapy found that K. pneumoniae has a tigecycline resistance rate of 2.6% [4].

In summary, Enterococcus faecium, Acinetobacter baumannii, and Klebsiella pneumoniae have shown resistance to tigecycline, according to various studies.

Sources:
[1] <https://www.drugpatentwatch.com/drugs/tigecycline>
[2] <https://academic.oup.com/jac/article/65/1/15/2538747>
[3] <https://jcm.asm.org/content/51/11/3921>
[4] <https://academic.oup.com/jac/article/65/1/15/2538747>