# Molecular detection and ultrastructure characterization of some drug-resistant Gram-negative bacteria isolated from bladder cancer patients

## TL;DR

This study examines drug-resistant Gram-negative bacteria from bladder cancer patients, focusing on their resistance patterns and structural features.

## Contribution

The study provides new insights into the ultrastructural and genetic characteristics of carbapenem-resistant Gram-negative bacteria in bladder cancer patients.

## Key findings

- High resistance to antibiotics was observed in Klebsiella pneumoniae, Escherichia coli, and Pseudomonas aeruginosa isolates.
- blaIMP was the most prevalent carbapenemase gene detected among the isolates.
- Transmission electron microscopy revealed structural changes linked to antimicrobial resistance.

## Abstract

Urinary tract infections (UTIs) are among the most common and potentially fatal illnesses that cancer patients experience. Infections in general are a major cause of morbidity and mortality in this population. The objective of this investigation was to detect some Gram-negative bacteria recovered from different urine specimens isolated from bladder cancer patients and examine their ultrastructural characteristics.

Gram-negative bacteria that are resistant to carbapenems were identified and isolated. Klebsiella pneumoniae, Escherichia coli, and Pseudomonas aeruginosa were then tested for employing meropenem in the phenotypic modified Hodge test (MHT), the modified carbapenem inactivation technique (mCIM), and the combined disk test (CDT). Genotypic detection of bacterial isolates was studied using the blaNDM, blaVIM, and blaIMP carbapenemase genes. 50 isolates (K. pneumoniae, E. coli, and P. aeruginosa) were tested for plasmid-mediated carbapenemase genes. Finally, agarose gel electrophoresis was used to investigate the polymerase chain reaction of blaNDM, blaVIM, and blaIMP carbapenemase genes. The structural characteristics of E. coli, P. aeruginosa, and K. pneumoniae were analyzed using transmission electron microscopy (TEM) to observe bacterial ultrastructure and illustrate cellular changes consistent with antimicrobial resistance. Gram-negative bacterial isolates included 35 K. pneumoniae, E. coli, and P. aeruginosa recovered from the study’s different urine samples. The resistance profile of K. pneumoniae and E. coli was greater than 80% for all tested antibiotics. Amikacin also exhibited high resistance at 80% (i.e., 20% susceptibility). The resistance profile of P. aeruginosa exceeded 100% for all examined antibiotics. Notably, amikacin was the single agent to which K. pneumoniae and E. coli demonstrated any measurable susceptibility (20%), distinguishing it as the best-performing antibiotic among the tested drugs, despite its overall limited efficacy. Unfortunately, high resistance was observed for all other examined antibiotics. The obtained results of MHT, mCIM, and CDT tests revealed that 82%, 32%, and 74% of isolated bacteria were carbapenem-resistant, respectively. PCR data revealed that blaIMP is the most relevant gene, followed by blaNDM and finally blaVIM, with 36%, 32%, and 22%, respectively. The current study showed a positive result of PCR for blaNDM, blaVIM genes, and blaIMP, respectively.

Isolates that produced carbapenemase exhibited high levels of resistance to numerous antimicrobials employed in this investigation. The study focused on the genotypic detection of blaNDM, blaVIM, and blaIMP. To obtain a thorough understanding of the existence of high-risk clones with antimicrobial resistance, carbapenemase genes containing Gram-negative isolates were necessary. The study recommends that the evaluation of the importance of bacterial resistance in human therapies would undoubtedly reap major benefits upon the use of difficult-to-treat resistance (DTR) in clinical practice and at the bedside.