Kim et al. 2019. Microbiota-derived lantibiotic restores resistance against vancomycin-resistant Enterococcus. Nature.

Summarized from DalMUG group discussion and written by: Jacob Nearing

Summary

Infection by vancomycin-resistant enterococcus remains a large issue for patients undergoing treatment within hospitals. It is also known that the use of antibiotics by patients within the hospital can lead to the expansion of VRE within the intestines. As it has become more and more difficult to develop novel antibiotic strategies, researchers have turned to other avenues to fight VRE. In this report, Kim et al. show that the administration of a bacterial community consisting of Clostridium bolteae, Blautia producta, Bacteroides sartorii and Parabacteroides distasonis can lead to the depletion of VRE in VRE colonized mice. The authors go on to further show that the specific strain of Blautia producta used within their study BP(scsk) is required for VRE depletion as another strain BP(control) did not deplete VRE in mice. Finally, the authors were able to identify a lantibiotic encoded by BP(scsk) that was responsible for VRE depletion.

Points of Interest

• We were interested to see that administration of the commensal community was much more effective than the lantibiotic itself.
• We liked that the authors measured VRE colonization using both 16S rRNA sequencing and CFU per gram. It showed clear differences in interpretation between relative abundance data and absolute counts.
• It was interesting to see that of the 39 different Blautia strains tested only their strain encoded the lantibiotic of interest, despite the gallidermin superfamily domain being found in the gut microbiome of 7/15 healthy stool donors.
• It was nice to see that the community was isolated from human donors indicating that it has potential for human colonization.

Points of Confusion

• While the lantibiotic from BPscsk is capable of killing VRE, it is unclear how many other gram negative commensal bacterial it may impact, which could lead to colonization of other gram positive pathogens or other unwanted gram positive commensal bacteria.
• We were slightly confused by the cutoffs chosen to identify people with “low” and “high” alpha diversity.
• It would have been nice to investigate why administration of the lantibiotic on its own was not as effective as administration of the community.