Professor Kai-Chih Chang’s team at Tzu Chi University has discovered a novel approach to combat multi-drug-resistant Acinetobacter nosocomialis

In recent years, hospitals have witnessed a rise in the prevalence of “Acinetobacter nosocomialis,” a Gram-negative bacillus from the Acinetobacter genus. This increase is concerning due to the bacterium’s growing resistance to antibiotics. In response, scientists are exploring innovative strategies to tackle such bacteria. One promising direction is the use of bacteriophages as a therapeutic option, although research in this area, specifically targeting A. nosocomialis, is still in its early stages.

Professor Kai-Chih Chang’s team in the Department of Laboratory Medicine and Biotechnology at Tzu Chi University isolated two bacteriophages, TCUAN1 and TCUAN2, from sewage wastewater, showing potential in combating A. nosocomialis. Their research involved a range of experiments including Transmission Electron Microscopy (TEM) for visual analysis, host specificity studies, and genomic sequencing to understand the phages’ biological properties and genetic makeup. Additionally, they focused on TCUAN2 for further investigation, successfully extracting a substance known as “endolysin,” which demonstrated effectiveness against this type of bacteria.

The experimental results showed that both TCUAN1 and TCUAN2 have a broad host range and can rapidly adhere to the bacterial surface. Further analysis indicated that compared to TCUAN1, TCUAN2 has a shorter latent period and a larger burst size, meaning it can produce more phages after infection, which in turn infect more bacteria. Due to its superior antibacterial activity, TCUAN2 was injected into mice infected with A. nosocomialis. The results showed a significant reduction in bacterial load in blood and a notable increase in the mice’s survival rate. Lastly, the endolysin protein, cloned and purified from TCUAN2, also demonstrated antibacterial activity when used.

This study confirms that phage therapy can combat multidrug-resistant bacteria.. By understanding the characteristics of these phages, Professor Chang’s research team can develop more effective strategies to combat these pathogens, while also offering new solutions to the issue of antibiotic resistance in the future.

Reference:

Pekkle Lam HY, Lai MJ, Wu WJ, Chin YH, Chao HJ, Chen LK, Peng SY, Chang KC. Isolation and characterization of bacteriophages with activities against multi-drug-resistant Acinetobacter nosocomialis causing bloodstream infection in vivo. J Microbiol Immunol Infect. 2023 Oct; 56(5):1026-1035. doi: 10.1016/j.jmii.2023.07.012. Epub 2023 Aug 5. PMID: 37586915