Antibacterial effects of single phage and phage cocktail against multidrug-resistant Klebsiella pneumoniae isolated from diabetic foot ulcer.

Diabetic foot ulcer (DFU) is associated with long-term hospitalization and amputation. Antibiotic resistance has made the infection eradication more difficult. Hence, seeking alternative therapies such as phage therapy seems necessary. Bacteriophages are viruses targeting specific bacterial species. Klebsiella pneumoniae (K. pneumoniae) is among causative agents of the DFU. In this study, the therapeutic effects of single phage and phage cocktail were investigated against multidrug-resistant (MDR) K. pneumonia isolated from DFU. Bacteriophages were isolated from animal feces and sewage samples, and were enriched and propagated using K. pneumoniae as the host. Thirty K. pneumoniae clinical isolates were collected from hospitalized patients with DFU. The antibiotic susceptibility pattern was determined using agar disk diffusion test. The phages' morphological traits were determined using transmission electron microscopy (TEM). The killing effect of isolated phages was assessed using plaque assay. Four phage types were isolated and recognized including KP1, KP2, KP3, and KP4. The bacterial rapid regrowth was observed following each single phage-host interaction, but not phage cocktail due to the evolution of mutant strains. Phage cocktail demonstrated significantly higher antibacterial activity than each single phage (p < 0.05) without any bacterial regrowth. The employment of phage cocktail was promising for the eradication of MDR-K. pneumoniae isolates. The development of phage therapy in particular, phage cocktail is promising as an efficient approach to eradicate MDR-K. pneumoniae isolated from DFU. The application of a specific phage cocktail can be investigated to try and achieve the eradication of various infections.

Comparison of Isoenzyme Pattern of Echinococcus granulosus sensu stricto (G1-G3) and E. canadensis (G6/G7) Protoscoleces

Background: Different genotypes of Echinococcus granulosus sensu lato (s.l.) infect humans and ungulate animals, causing cystic echinococcosis. Simultaneous isoenzyme, as well as molecular characterizations of this parasite, has not yet been investigated in Iran. The present study aimed to evaluate the isoenzyme pattern of the E. granulosus sensu stricto (s.s.) and E. canadensis genotypes in Iran. Methods: A total of 32 (8 humans and 24 animals) cystic echinococcosis cysts were isolated from Shiraz, Tehran, Ilam, and Birjand from May 2018 to December 2020. The DNAs were extracted and their genotypes were determined by molecular methods. Enzymes were extracted from the cysts and subjected to polyacrylamide gel electrophoresis. The activities of glucose-6-phosphate sehydrogenase (G6PD), malate dehydrogenase (MDH), malic enzyme (ME), nucleoside hydrolyse 1 (NH1), and isocitrate dehydrogenase (ICD) were examined in the cyst samples using isoenzyme method and compared it with the genotyping findings. Results: DNA sequence analysis of the samples showed that the specimens contained 75% E. granulosus s.s. (G1) and 25% E. canadensis (G6) genotypes. The isoenzyme pattern of ICD in both genotypes produced a six-band pattern with different relative factors. The G6PD also produced two bands with different relative migrations in both genotypes. The MDH and NH1 systems revealed a two-band pattern, while only one band was generated in the ME enzyme in the E. granulosus s.s. genotype. In the E. canadensis, the MDH and NH1 enzymes showed one band, and the ME enzyme represented a two-band pattern. Conclusion: Our findings suggest that E. granulosus s.s. and E. canadensis genotypes have entirely different isoenzyme patterns for NH1, G6PD, MDH, and ME.