Detection of Tigecycline Resistance in Multi-Drug and Extremely Drug-Resistant Gram Negative Bacteria in Baghdad/ Iraq

Tigecycline is a parenteral glycylcycline antibiotic that is bacteriostatic and possesses structural similarities with tetracyclines. Approximately 130 species both Gram-positive and Gram-negative are affected by these. and they provide resistance to tetracycline antibiotics, particularly the first- and second-generation types. During a period extended from September 2021 to February 2022, 166 Gram-negative bacteria were recovered from various clinical specimens at various hospitals in Baghdad, Iraq, including sputum, blood, wounds , urine, burns, and ear swabs. Out of 166 Gram negative isolates, 144/166 (86.75%) isolates were identified as Klebsiella pneumoniae subsp. pneumoniae, Pseudomonas aeruginosa, Acinetobacter baumannii and Escherichia coli and remining 22 isolates (13.25%) represented other Gram-negative species. The sensitivity test results found that 14 isolates (9.72%) were resist to tigecycline; additionally, all 14 isolates of P. aeruginosa, A. baumannii, K. pneumoniae, and E. coli that were resistant to tigecycline were highly drug resistant. From the results noticed that the highest isolation rate of tigecycline resistant isolates was from blood specimens 8(57.14%), followed by sputum specimens 4(28.57%) and burn specimens 2(14.20%). those pathogens may have developed resistance to tigecycline during therapy. Conclusions: The highest isolation rate of tigecycline resistant isolates was from blood specimens, followed by sputum specimens and burn specimens. All the studied Gram negative isolates showed a high level of antimicrobial resistant.