Acinetobacter baumannii: Mechanisms of Antimicrobial Resistance

Gram-negative non-fermenting bacteria Acinetobacter baumannii are a common cause of severe complications (pneumonia, bacteremia, sepsis) in the clinic of internal diseases, especially in patients with weakened immune system: 3,2% of bacteremia and sepsis cases are associated with A. baumannii, with mortality rate 26–91%. A. baumannii has the ability to rapidly acquire antimicrobial resistance. In recent decades, strains with multiple resistance to antimicrobial drugs have emerged, including beta-lactams, including carbapenems, aminoglycosides, and fluoroquinolones, which are the drugs of choice in the treatment of severe hospital infections caused by Gram-negative microorganisms. Globally, about 45% of A. baumannii isolates are multidrug-resistant, with multidrug resistance reaching 90% in the Middle East, Southern Europe, and North Africa, and 60% in China. The prevalence of polyresistant strains of A. baumannii in patients with nosocomial pneumonia associated with mechanical ventilation is estimated at 80%. The main mechanisms of antimicrobial resistance of the pathogen are impaired permeability of the cell wall to antibiotics as a result of modification of porin proteins, activation of efflux pump systems, production of enzymes that destroy antibacterial drugs, and biofilm formation. The review examines the molecular basis of the formation of resistance to antibacterial drugs in A. baumannii.

1. Ren X., Palmer L. D. Acinetobacter metabolism in infection and antimicrobial resistance. Infect Immun. 2023; 91 (6): e0043322. doi: 10.1128/iai.00433-22.

2. Wu H.J., Xiao Z. G., Lv X.J., Huang H. T., Liao C., Hui C. Y. et al. Drugresistant Acinetobacter baumannii: from molecular mechanisms to potential therapeutics (Review). Exp Ther Med. 2023; 25 (5): 209. doi: 10.3892/etm.2023.11908.

3. Cavallo I., Oliva A., Pages R., Sivori F., Truglio M., Fabrizio G. et al. Acinetobacter baumannii in the critically ill: complex infections get complicated. Front Microbiol. 2023; 14: 1196774. doi: 10.3389/fmicb.2023.1196774.

4. Svistunov S. A., Kuzin A. A., Suborova T. N., Ogarkov P. I., Zharkov D. A., Medvedev I. Y. The role of Acinetobacter spp. in health care-associated infections etiology in patients of surgical departments. Meditsina v Kuzbasse. 2013; 12 (2): 59–62. (in Russian)

5. Denissen J., Reyneke B., Waso-Reyneke M., Havenga B., Barnard T., Khan S. et al. Prevalence of ESKAPE pathogens in the environment: Antibiotic resistance status, community-acquired infection and risk to human health. Int J Hyg Environ Health. 2022; 244: 114006. doi: 10.1016/j.ijheh.2022.114006.

6. Sun C., Yu Y., Hua X. Resistance mechanisms of tigecycline in Acinetobacter baumannii. Front. Cell. Infect. Microbiol. 2023; 13: 1141490. doi: 10.3389/fcimb.2023.1141490.

7. Park J., Kim M., Shin B., Kang M., Yang J., Lee T. K. et al. A novel decoy strategy for polymyxin resistance in Acinetobacter baumannii. Elife. 2021; 10: e66988. doi: 10.7554/eLife.66988.

8. Lupo A., Haenni M., Madec J. Antimicrobial resistance in Acinetobacter spp. and Pseudomonas spp. Microbiol Spectr. 2018; 6: 10.1128/microbiolspec.arba-0007-2017. doi: 10.1128/microbiolspec.arba-0007-2017.

9. Goncharova A. R., Gostev V. V., Kraeva L. A., Polev D. E., Goncharov N. E., Saitova A. T. et al. Phenotypical and molecular-genetic characteristics of Acinetobacter baumannii isolates from nosocomial infections with fatal outcomes. Problems in Medical Mycology. 2024; 26 (1): 60–65. (in Russian)

10. Shmakova M. A. Acinetobacter spp. as healthcare-associated pathogens: epidemiological features. Fundamental and Clinical Medicine. 2019; 4 (1): 66–72. (in Russian)

11. Timsit J. F., Garrait V., Misset B., Goldstein F. W., Renaud B., Carlet J. The digestive tract is a major site for Acinetobacter baumannii colonization in intensive care unit patients. J Infect Dis. 1993; 168 (5): 1336–1337. doi: 10.1093/infdis/168.5.1336.

12. Gorbich Yu. L., Karpov I. A., Krechikova O. I. Infektsii, vyzvannye Acinetobacter baumannii: faktory riska, diagnostika, lechenie, podkhody k profilaktike. Meditsinskie novosti. 2011; 5: 31–39. (in Russian)

13. Ayats J., Corbella X., Ardanuy C., Domínguez M. A., Ricart A., Ariza J. et al. Epidemiological significance of cutaneous, pharyngeal, and digestive tract colonization by multiresistant Acinetobacter baumannii in ICU patients. J Hosp Infect. 1997; 37 (4): 287–295. doi: 10.1016/s0195-6701(97)90145-6.

14. Zheng Y., Xu N., Pang J., Han H., Yang H., Qin W. et al. Colonization with extensively drug-resistant Acinetobacter baumannii and prognosis in critically ill patients: an observational cohort study. Front Med (Lausanne). 2021; 8: 667776. doi: 10.3389/fmed.2021.667776.

15. Knauf G. A., Powers M. J., Herrera C. M., Trent M. S., Davies B. W. Acinetobactin-mediated inhibition of commensal bacteria by Acinetobacter baumannii. mSphere. 2022; 7 (1): e0001622. doi: 10.1128/msphere.00016-22.

16. Wong S. C., Chen J. H., Chau P. H., So S.Y., AuYeung C.H., Yuen L. L. et al. Gastrointestinal colonization of carbapenem-resistant Acinetobacter baumannii: what is the implication for infection control? Antibiotics (Basel). 2022; 11 (10): 1297. Published 2022 Sep 22. doi: 10.3390/antibiotics11101297.

17. Martín-Aspas A., Guerrero-Sánchez F. M., García-Colchero F., RodríguezRoca S., Girón-González J. A. Differential characteristics of Acinetobacter baumannii colonization and infection: risk factors, clinical picture, and mortality. Infect Drug Resist. 2018; 11: 861–872. doi: 10.2147/IDR.S163944.

18. Itani R., Khojah H. M.J., Karout S., Rahme D., Hammoud L., Awad R. et al. Acinetobacter baumannii: assessing susceptibility patterns, management practices, and mortality predictors in a tertiary teaching hospital in Lebanon. Antimicrob Resist Infect Control. 2023; 12 (1): 136. doi: 10.1186/s13756-023-01343-8.

19. Diekema D. J., Hsueh P. R., Mendes R. E., Pfaller M. A., Rolston K. V., Sader H. S., Jones R. N. The microbiology of bloodstream infection: 20-year trends from the SENTRY antimicrobial surveillance program. Antimicrob Agents Chemother. 2019; 63 (7): e00355-19. doi: 10.1128/AAC.00355-19.

20. Nutman A., Temkin E., Wullflart L., Schechner V., Schwaber M. J., Carmeli Y. Acinetobacter baumannii bloodstream infections: a nationwide study in Israel. Microorganisms. 2023; 11 (9): 2178. doi: 10.3390/microorganisms11092178.

21. Andrianopoulos I., Maniatopoulou T., Lagos N., Kazakos N., Papathanasiou A., Papathanakos G. et al. Acinetobacter baumannii bloodstream infections in the COVID-19 era: a comparative analysis between COVID-19 and non-COVID-19 critically ill patients. Microorganisms. 2023; 11 (7): 1811. doi: 10.3390/microorganisms11071811.

22. Rangel K., De-Simone S. G. Acinetobacter baumannii during COVID-19: what is the real pandemic? Pathogens. 2022; 12 (1): 41. doi: 10.3390/pathogens12010041.

23. Vrancianu C. O., Cristian R-E., Dobre E-G., Zenoaga-Barbarosie C., Chirea E-T., Crunteanu I. et al. The impact of Acinetobacter baumannii infections in COVID-19 patients admitted in hospital intensive care units. Biol. Life Sci. Forum. 2024; 31: 1. doi: https://doi.org/10.3390/ECM2023-16479.

24. Touny A., Rageh F., Riad E., Sakr M. A., Abdelhady S. A., Elgamal R. et al. Incidence of co-infection and its impact on COVID-19 patients admitted in the intensive care unit. Egyptian Journal of Anaesthesia. 2023; 39 (1): 141–148. doi: https://doi.org/10.1080/11101849.2023.2175404.

25. Alenazi T. A., Shaman M. S. B., Suliman D. M., Alanazi T. A., Altawalbeh S. M., Alshareef H., et al. The impact of multidrug-resistant Acinetobacter baumannii infection in critically ill patients with or without COVID-19 infection. Healthcare (Basel). 2023; 11 (4): 487. doi: 10.3390/healthcare11040487.

26. Boral J., Genç Z., Pýnarlýk F., Ekinci G., Kuskucu M. A., Ýrkören P. et al. The association between Acinetobacter baumannii infections and the COVID-19 pandemic in an intensive care unit. Sci Rep. 2022; 12 (1): 20808. doi: 10.1038/s41598-022-25493-8.

27. AliMohammadi A., Chezani-Sharahi N., Hezaveh Z. A., Abbasi E., Shariati A., Ghaznavi-Rad E. The significant role of carbapenems-resistant Acinetobacter baumannii in mortality rate of patients with COVID-19. Vacunas. 2023; 24 (1): 13–18. doi: 10.1016/j.vacun.2022.10.004.

28. Agyepong N., Fordjour F., Owusu-Ofori A. Multidrugresistant Acinetobacter baumannii in healthcare settings in Africa. Front. Trop. Dis. 2023; 4: 1110125. doi: 10.3389/fitd.2023.1110125.

29. Ibrahim S., Al-Saryi N., Al-Kadmy I. M.S., Aziz S. N. Multidrug-resistant Acinetobacter baumannii as an emerging concern in hospitals. Mol Biol Rep. 2021; 48 (10): 6987–6998. doi: 10.1007/s11033-021-06690-6.

30. Weinberg S. E., Villedieu A., Bagdasarian N., Karah N., Teare L., Elamin W. F. Control and management of multidrug resistant Acinetobacter baumannii: A review of the evidence and proposal of novel approaches. Infect Prev Pract. 2020; 2 (3): 100077. doi: 10.1016/j.infpip.2020.100077.

31. Kozlova N. S., Barantsevich N. E., Ivanova L. V., Goik V. G., Barantsevich E. P. Resistance to antibiotics in Enterobacteriaceae, isolated from urine in a multidisciplinary medical centre. Problemy meditsinskoi mikologii. 2015; 17 (3): 22–26 (in Russian)

32. Yousefi Nojookambari N., Sadredinamin M., Dehbanipour R., Ghalavand Z., Eslami G., Vaezjalali M. et al. Prevalence of β-lactamaseencoding genes and molecular typing of Acinetobacter baumannii isolates carrying carbapenemase OXA-24 in children. Ann Clin Microbiol Antimicrob. 2021; 20 (1): 75. doi: 10.1186/s12941-021-00480-5.

33. Chebotar I. V., Kryzhanovskaya O. A., Alyabieva N. M., Savinova T. A., Bocharova Yu. A., Lazareva A. V., Polikarpova S. V., Karaseva O. V., Mayanskiy N. F. Genotypes and β-lactamase gene carriage in carbapenem-resistant acinetobacter baumannii isolated in Moscow. Antibiot Khimioter = Antibiotics and Chemotherapy. 2017; 62 (11–12): 29–34. (in Russian)

34. Barantsevich N. E., Barantsevich E. P. Antimicrobial therapy of sepsis caused by carbapenem-resistant Klebsiella pneumoniae in patients with hematological malignancies. Klinicheskaya Mikrobiologiya i Antimikrobnaya Khimioterapiya. 2022; 24 (4): 383–387 (in Russian)

35. Lazareva I. V., Ageevets V. A., Sidorenko S. V. Antibiotic resistance: the role of carbapenemases. Meditsina Ekstremal’nykh Situatsiy (Medicine of Extreme Situations). 2018; 20 (3): 320–328. (in Russian)

36. Shek E. A., Sukhorukova M. V., Eidel‘shtein M. V., Skleenova E. Yu., Ivanchik N. V., Shaidullina E. R., et al. Antimicrobial resistance, carbapenemase production, and genotypes of nosocomial Acinetobacter spp. isolates in Russia: results of multicenter epidemiological study «MARATHON 2015–2016» Klinicheskaya Mikrobiologiya i Antimikrobnaya Khimioterapiya. 2019; 21 (2): 171–180. (in Russian)

37. Ma C., McClean S. Mapping Global Prevalence of Acinetobacter baumannii and recent vaccine development to tackle it. Vaccines (Basel). 2021; 9 (6): 570. doi: 10.3390/vaccines9060570.

38. Lee H. Y., Chen C. L., Wu S.R., Huang C. W., Chiu C. H. Risk factors and outcome analysis of acinetobacter baumannii complex bacteremia in critical patients. Crit Care Med. 2014; 42 (5): 1081–1088. doi: 10.1097/CCM.0000000000000125.

39. Gudueva E. N., Chemisova O. S. Pathogenicity factors of Acinetobacter baumannii. Medical Herald of the South of Russia. 2023; 14 (1): 66–74. doi: https://doi.org/10.21886/2219-8075-2023-14-1-66-74. (in Russian)

40. Mohammed Y., Muhammad A. S., Zainu S. M., Jimoh A. K., Olowo-Okere A., Ogunyinka I. A. et al. Outbreak of multidrug-resistant Acinetobacter baumannii in a tertiary health center from Northwestern Nigeria. Ann Afr Med. 2024; 23 (1): 40–45. doi: 10.4103/aam.aam_141_23.

41. Lee C. R., Lee J. H., Park M., Park K. S., Bae I. K., Kim Y. B. et al. Biology of Acinetobacter baumannii: pathogenesis, antibiotic resistance mechanisms, and prospective treatment options. Front Cell Infect Microbiol. 2017; 7: 55. doi: 10.3389/fcimb.2017.00055.

42. Kyriakidis I., Vasileiou E., Pana Z. D., Tragiannidis A. Acinetobacter baumannii antibiotic resistance mechanisms. Pathogens. 2021; 10 (3): 373. doi: 10.3390/pathogens10030373.

43. Castanheira M., Mendes R. E., Gales A. C. Global epidemiology and mechanisms of resistance of Acinetobacter baumannii-calcoaceticus complex. Clin Infect Dis. 2023; 76: S166–S178. doi: 10.1093/cid/ciad109.

44. Khokhlova O. Е., Larionova I. A., Perianova O. V., Kozlov R. S., Eidelshtein M. V., Modestov A. A. et al. The mechanisms of antibiotic resistance in major pathogens of purulent-inflammatory complications in cancer patients. Russian Journal of Infection and Immunity. 2021; 11 (2): 324–336. doi: 10.15789/2220-7619-TMO-1379. (in Russian)

45. Singh H., Thangaraj P., Chakrabarti A. Acinetobacter baumannii: a brief account of mechanisms of multidrug resistance and current and future therapeutic management. J Clin Diagn Res. 2013; 7 (11): 2602–5. doi: 10.7860/JCDR/2013/6337.3626.

46. Cain A. K., Hamidian M. Portrait of a killer: uncovering resistance mechanisms and global spread of Acinetobacter baumannii. PLoS Pathog. 2023; 19 (8): e1011520. doi: 10.1371/journal.ppat.1011520.

47. Rafailidis P., Panagopoulos P., Koutserimpas C., Samonis G. Current therapeutic approaches for multidrug-resistant and extensively drugresistant Acinetobacter baumannii infections. Antibiotics (Basel). 2024; 13 (3): 261. doi: 10.3390/antibiotics13030261.

48. Naseef Pathoor N., Viswanathan A., Wadhwa G., Ganesh P. S. Understanding the biofilm development of Acinetobacter baumannii and novel strategies to combat infection. APMIS. 2024; 132 (5): 317–335. doi: 10.1111/apm.13399.

49. Shi J., Cheng J., Liu S., Zhu Y., Zhu M. Acinetobacter baumannii: an evolving and cunning opponent. Front Microbiol. 2024; 15: 1332108. doi: 10.3389/fmicb.2024.1332108.

50. Marino A., Augello E., Stracquadanio S., Bellanca C. M., Cosentino F., Spampinato S. et al. Unveiling the secrets of Acinetobacter baumannii: resistance, current treatments, and future innovations. Int J Mol Sci. 2024; 25 (13): 6814. doi: 10.3390/ijms25136814.

51. Saikia S., Gogoi I., Puzari M., Sharma M., Chetia P. Identification of novel drug targets to counteract efflux pump mediated multidrug resistance in Acinetobacter baumannii. Gene Reports. 2024; 37: 102013.

52. Abdi S. N., Ghotaslou R., Ganbarov K., Mobed A., Tanomand A., Yousefi M. et al. Acinetobacter baumannii efflux pumps and antibiotic resistance. Infect Drug Resist. 2020; 13: 423–434. doi: 10.2147/IDR.S228089.

53. Zack K. M., Sorenson T., Joshi S. G. Types and mechanisms of efflux pump systems and the potential of efflux pump inhibitors in the restoration of antimicrobial susceptibility, with a special reference to Acinetobacter baumannii. Pathogens. 2024; 13 (3): 197. doi: 10.3390/pathogens13030197.

54. Gaurav A., Bakht P., Saini M., Pandey S., Pathania R. Role of bacterial efflux pumps in antibiotic resistance, virulence, and strategies to discover novel efflux pump inhibitors. Microbiology. 2023; 169: 001333. doi: 10.1099/mic.0.001333.

55. Garnacho-Montero J., Timsit J. F. Managing Acinetobacter baumannii infections Curr Opin Infect Dis. 2019; 32 (1): 69–76. doi: 10.1097/QCO.0000000000000518.

56. Morrison L., Zembower T. R. Antimicrobial resistance. Gastrointest Endosc Clin N Am. 2020; 30 (4): 619–635. doi: 10.1016/j.giec.2020.06.004.

57. Evans B. A., Amyes S. G. OXA β-lactamases. Clin Microbiol Rev. 2014; 27 (2): 241–63. doi: 10.1128/CMR.00117-13.

58. Saral A., Leonard D. A., Duzgun A. O., Cicek A. C., June C. M., Sandalli C. Kinetic characterization of GES-22 β-lactamase harboring the M169L clinical mutation. J Antibiot (Tokyo). 2016; 69 (12): 858–862. doi: 10.1038/ja.2016.48.

59. Kryzhanovskaya O. A., Lazareva A. V., Chebotar I. V., Bocharova Yu.A., Mayansky N. A. Spectrum of antibiotic resistance and prevalence of OXA-carbapenemases among Acinetobacter baumannii strains, isolated from patients of surgical and reanimation departments in Moscow. Zhurnal Mikrobiologii, Epidemiologii, Immunobiologii. 2016; 1: 40–45 (in Russian)

60. Chan K. W., Liu C. Y., Wong H. Y., Chan W. C., Wong K. Y., Chen S. Specific Amino Acid Substitutions in OXA-51-Type β-Lactamase enhance catalytic activity to a level comparable to carbapenemase OXA-23 and OXA-24/40. Int J Mol Sci. 2022; 23 (9): 4496. doi: 10.3390/ijms23094496. PMID: 35562886; PMCID: PMC9105447.

61. Wang L., Chen Q. W., Qin Y. C., Yi X. L., Zeng H. Analysis of carbapenemresistant Acinetobacter baumannii carbapenemase gene distribution and biofilm formation. Int J Mol Epidemiol Genet. 2024; 15 (1): 1–11. doi: 10.62347/KBSB9946.

62. Moussa S. H., Shapiro A. B., McLeod S. M., Iyer R., Carter N. M., Tsai Y-K., Siu L. K., Miller A. A. Molecular drivers of resistance to sulbactam-durlobactam in contemporary clinical isolates of Acinetobacter baumannii. Antimicrob Agents Chemother. 2023; 15; 67 (11): e0066523. doi: 10.1128/aac.00665-23.

63. Findlay J., Poirel L., Bouvier M., Nordmann P. In vitro activity of sulbactam-durlobactam against carbapenem-resistant Acinetobacter baumannii and mechanisms of resistance. J Glob Antimicrob Resist. 2022; 30: 445–450. doi: 10.1016/j.jgar.2022.05.011.

64. Tahbaz S. V., Azimi L., Lari A. R. Characterization of aminoglycoside resistance mechanisms in Acinetobacter baumannii isolates from burn wound colonization. Ann Burns Fire Disasters. 2019; 32 (2): 115–121.

65. Rashvand P., Peymani A., Mohammadi M., Karami A. A., Samimi R., Hajian S. et al. Molecular survey of aminoglycoside-resistant Acinetobacter baumannii isolated from tertiary hospitals in Qazvin, Iran. New Microbes New Infect. 2021; 42: 100883. doi: 10.1016/j.nmni.2021.100883.

66. Ghasemi S., Shoja S., Mazloomirad F., Ghatee M. A., Rashidpoor F., Khoramrooz S. S. et al. Prevalence of aminoglycoside and carbapenemase resistance genes and biofilm formation among clinical isolates of Acinetobacter baumannii in Iran. Mediterr J Infect Microb Antimicrob. 2022; 11 (1): 32–32. doi: 10.4274/mjima.galenos.2022.2021.32.

67. Jouybari M. A., Ahanjan M., Mirzaei B., Goli H. R. Role of aminoglycoside-modifying enzymes and 16S rRNA methylase (ArmA) in resistance of Acinetobacter baumannii clinical isolates against aminoglycosides. Rev Soc Bras Med Trop. 2021; 54: e05992020. doi: 10.1590/0037-86820599-2020.

68. Zárate S. G., De la Cruz Claure M. L., Benito-Arenas R., Revuelta J., Santana A. G., Bastida A. Overcoming aminoglycoside enzymatic resistance: design of novel antibiotics and inhibitors. Molecules. 2018; 23 (2): 284. doi: 10.3390/molecules23020284.

69. Nie L., Lv Y., Yuan M., Hu X., Nie T., Yang X. et al. Genetic basis of high level aminoglycoside resistance in Acinetobacter baumannii from Beijing, China. Acta Pharm Sin B. 2014; 4 (4): 295–300. doi: 10.1016/j.apsb.2014.06.004.

70. Ashouri P., Mohammadshahi J., Nikbin V. S., Peeridogaheh H., Mohammadi-Ghalehbin B. et al. Antimicrobial resistance, integron carriage, and fluoroquinolone resistance genes in Acinetobacte baumannii isolates. Arch Clin Infect Dis. 2022; 17 (5): e120590. doi: https://doi.org/10.5812/archcid-120590.

71. Spencer A. C., Panda S. S. DNA Gyrase as a target for quinolones. Biomedicines. 2023; 11 (2): 371. doi: 10.3390/biomedicines11020371.

72. Hooper D. C., Jacoby G. A. Topoisomerase inhibitors: fluoroquinolone mechanisms of action and resistance. Cold Spring Harb Perspect Med. 2016; 6 (9): a025320. doi: 10.1101/cshperspect.a025320.

73. Noskin G. A. Tigecycline: A new glycylcycline for treatment of serious infections. Clinical Infectious Diseases. 2005; 41 (5): S303–S314. doi: 10.1086/431672.

74. Sato Y., Ubagai T., Tansho-Nagakawa S., Yoshino Y., Ono Y. Effects of colistin and tigecycline on multidrug-resistant Acinetobacter baumannii biofilms: advantages and disadvantages of their combination. Sci Rep. 2021; 11 (1): 11700. doi: 10.1038/s41598-021-90732-3.

75. Pankuch G. A., Appelbaum P. C. Postantibiotic effect of tigecycline against 14 gram-positive organisms. Antimicrob Agents Chemother. 2009; 53 (2): 782–784. doi: 10.1128/AAC.01122-08.

76. Yaghoubi S., Zekiy A. O., Krutova M., Gholami M., Kouhsari E., Sholeh M. et al. Tigecycline antibacterial activity, clinical effectiveness, and mechanisms and epidemiology of resistance: narrative review. Eur J Clin Microbiol Infect Dis. 2022; 41 (7): 1003–1022. doi: 10.1007/s10096-020-04121-1.

77. Hua X., He J., Wang J., Zhang L., Zhang L., Xu Q. et al. Novel tigecycline resistance mechanisms in Acinetobacter baumannii mediated by mutations in adeS, rpoB and rrf. Emerg Microbes Infect. 2021; 10 (1): 1404–1417. doi: 10.1080/22221751.2021.1948804.

78. Kornelsen V., Kumar A. Update on multidrug resistance efflux pumps in Acinetobacter spp. Antimicrob Agents Chemother. 2021; 65 (7): e0051421. doi: 10.1128/AAC.00514-21.

79. Chen C., Cui C. Y., Yu J. J., He Q., Wu X. T., He Y. Z. et al. Genetic diversity and characteristics of high-level tigecycline resistance Tet (X) in Acinetobacter species. Genome Med. 2020; 12 (1): 111. doi: 10.1186/s13073-020-00807-5.

80. Ajiboye T. O., Skiebe E., Wilharm G. Contributions of RecA and RecBCD DNA repair pathways to the oxidative stress response and sensitivity of Acinetobacter baumannii to antibiotics. Int J Antimicrob Agents. 2018; 52 (5): 629–636. doi: 10.1016/j.ijantimicag.2018.07.022.

81. Cheah S. E., Johnson M. D., Zhu Y., Tsuji B. T., Forrest A., Bulitta J. B. et al. Polymyxin resistance in Acinetobacter baumannii: genetic mutations and transcriptomic changes in response to clinically relevant dosage regimens. Sci Rep. 2016; 6: 26233. doi: 10.1038/srep26233.

82. Mondal A. H., Khare K., Saxena P., Debnath P., Mukhopadhyay K., Yadav D. A Review on colistin resistance: an antibiotic of last resort. Microorganisms. 2024; 12 (4): 772. doi: 10.3390/microorganisms12040772.

83. Novović K., Jovčić B. Colistin resistance in Acinetobacter baumannii: molecular mechanisms and epidemiology. Antibiotics (Basel). 2023; 12 (3): 516. doi: 10.3390/antibiotics12030516.

84. Hussein N. H., Al-Kadmy I. M. S., Taha B. M., Hussein J. D. Mobilized colistin resistance (mcr) genes from 1 to 10: a comprehensive review. Mol Biol Rep. 2021; 48 (3): 2897–2907. doi: 10.1007/s11033-021-06307-y.

85. Avila-Novoa M. G., Solís-Velázquez O. A., Rangel-López D. E., GonzálezGómez J. P., Guerrero-Medina P. J. et al. Biofilm formation and detection of fluoroquinoloneand carbapenem-resistant genes in multidrug-resistant Acinetobacter baumannii. Can J Infect Dis Med Microbiol. 2019; 2019: 3454907. doi: 10.1155/2019/3454907.

86. Gedefie A., Demsis W., Ashagrie M., Kassa Y., Tesfaye M., Tilahun M. et al. Acinetobacter baumannii biofilm formation and its role in disease pathogenesis: a review. Infect Drug Resist. 2021; 14: 3711–3719. doi: 10.2147/IDR.S332051.

87. Roy S., Chowdhury G., Mukhopadhyay A. K., Dutta S., Basu S. Convergence of biofilm formation and antibiotic resistance in Acinetobacter baumannii infection. Front Med (Lausanne). 2022; 9: 793615. doi: 10.3389/fmed.2022.793615.

88. Choudhary M., Shrivastava R., Vashistt J. Acinetobacter baumannii biofilm formation: association with antimicrobial resistance and prolonged survival under desiccation. Curr Microbiol. 2022; 79: 361. doi: 10.1007/s00284-022-03071-5.

89. Mendes S. G., Combo S. I., Allain T., Domingues S., Buret A. G., Da Silva G. J. Co-regulation of biofilm formation and antimicrobial resistance in Acinetobacter baumannii: from mechanisms to therapeutic strategies. Eur J Clin Microbiol Infect Dis. 2023; 42 (12): 1405–1423. doi: 10.1007/s10096-023-04677-8.