Elevated Level of Imipenem-Resistant Gram-Negative Bacteria Isolated from Patients Attending Health Centers in North Gondar, Ethiopia

Abstract

Background

The frequent identification of resistant bacteria in hospitals constantly presents antimicrobial therapy with a challenge. Imipenem, once considered an extremely powerful antibiotic against multidrug-resistant bacterial infections, is losing its effectiveness. Its use in empirical therapy with inadequate or nonexistent antimicrobial stewardship programs has further triggered bacterial resistance in low-income countries. Therefore, this study aimed at identifying imipenem-resistant Gram-negative bacteria from patients who were referred to health centers in North Gondar, Ethiopia.

Methods

A total of 153 sputum samples were used to isolate Gram-negative bacteria. The isolates, which were resistant to imipenem, were identified by standard biochemical tests and 16S rRNA sequencing. The Kirby-Bauer disk diffusion method was used to determine the sensitivity or resistance of the isolate to diverse antimicrobial agents.

Results

The study identified 79 imipenem-resistant bacterial isolates from eight genera with clinically relevant microorganisms, including Acinetobacter baumannii (20.77%), Klebsiella pneumoniae (19.48%), Pseudomonas aeruginosa (16.88%), and Serratia marcescens (14.28%). Overall, imipenem-resistant bacterial isolates were detected in 31 samples (20.26%). Additionally, a remarkably high level of resistance to most antibiotics was observed among isolates of Klebsiella pneumoniae and Acinetobacter baumannii. Gentamycin is the most active antibiotic against many of the isolates, while β-lactams appear to be less effective.

Conclusion

The study indicated that many Gram-negative bacteria were resistant to imipenem with parallel resistances to other antimicrobials. Hence, the prescription of imipenem within the region should be according to the antibiotic resistance profiles of the multi-drug resistant bacteria.

Keywords:

• Gram-negative bacteria
• imipenem
• North Gondar
• 16S rRNA sequencing

Acknowledgments

The authors would like to thank Prof. Wolfgang Streit from the University of Hamburg for unreserved support with the 16S rRNA sequencing. We also thank the laboratory staff of the two health centers for their support in specimen collection.

Abbreviations

ATCC, American Type Culture Collection; AMR, antimicrobial resistance; CLSI, Clinical Laboratory Standard Institute; h, hours; LB, Luria-Bertani media; min, minutes; MDR, multidrug resistance; PCR, polymerase chain reaction; TSI, triple sugar iron agar.

Ethics Approval and Consent to Participate

Done as described earlier.

Author Contributions

All authors made a significant contribution to the work reported, whether that is in the conception, study design, execution, acquisition of data, analysis and interpretation, or in all these areas; took part in drafting, revising or critically reviewing the article; gave final approval of the version to be published; have agreed on the journal to which the article has been submitted; and agree to be accountable for all aspects of the work.

Author Details

Addis Ababa Science and Technology University, Department of Biotechnology, P.O.Box.16417, Addis Ababa, Ethiopia, and University of Gondar, Department of Biology, P.O.Box.196, Gondar, Ethiopia

Disclosure

The authors declare that they have no competing interests.