•  
  •  
 

Hilla University College Journal For Medical Science

Corresponding Author

Ameer Sabah Tayeh Al-Janabi

Authors ORCID

Ameer Sabah Tayeh Al-Janabi: https://orcid.org/0009-0002-0304-5282

Raghad Ali Sahib Al-Musawi: https://orcid.org/0000-0002-2736-4627

Document Type

Original Study

Keywords

blaCTX-M, mcr1, tetA and sul1, Nosocomial infections

Abstract

Background: Nosocomial infections primarily caused by a wide range of pathogenic bacteria that colonize healthcare environments and infect vulnerable patients. These infections are often associated with both Gram-negative and Gram-positive organisms, with Gram-negative bacteria being particularly prominent due to their high levels of antibiotic resistance.
Objectives: To detect antibiotic resistance genes (blaCTX-M, mcr1, tetA and sul1) produced by E. coli isolated from patients with nosocomial infections.
Materials and Methods: A total of 155 specimens were collected from patients with nosocomial infections at Marjan Medical City and Al-Sadeq Hospital in Al-Hillah Province between October 2025 and January 2026. Identification was performed using biochemical tests and the VITEK 2 system. All samples were cultured on MacConkey agar. Antibiotic susceptibility of E. coli was assessed using the Kirby–Bauer disk diffusion method on Mueller-Hinton agar. PCR was used to detect resistance genes (blaCTX-M, mcr-1, tetA, and sul1) after DNA extraction, with amplification carried out under standard conditions. PCR products were analyzed by agarose gel electrophoresis.
Results: Out of 155 specimens, Gram-negative bacteria were isolated from 144 (92.9%) samples, while 11 (7.1%) showed no growth. Out of 144 clinical samples, 46 isolates were diagnosed as E. coli. Only 20 isolates were further used to detect antibiotic resistance genes by PCR. The results showed that all 20 isolates (100%) of E. coli were possessed sul1gene, blaCTX-M and tetA were present in 19 isolates, while mcr1 detected only in 7 isolates.
Conclusion: The high prevalence of the resistance genes sul1, blaCTX-M, and tetA indicates a strong multidrug resistance pattern. The detection of these three genes in nearly all isolates reflects widespread resistance to sulfonamides, β -lactam antibiotics, and tetracyclines. In contrast, the lower detection of mcr-1 indicates that colistin resistance remains limited but still noteworthy.

Creative Commons License

Creative Commons Attribution 4.0 International License
This work is licensed under a Creative Commons Attribution 4.0 International License.

Download

Share

COinS