Isolation and Characterization of Novel Lytic Bacteriophages Infecting Epidemic Carbapenem-Resistant Klebsiella pneumoniae Strains

Abstract

Carbapenem-resistant Klebsiella pneumoniae (CRKP) poses a significant clinical problem given the lack of therapeutic options available. Alternative antibacterial agents, such as bacteriophages, can be used as a valuable tool to treat the infections caused by these highly resistant bacteria. In this study, we isolated 54 phages from medical and domestic sewage wastewater between July and September 2019 and determined their host ranges against 54 clinical CRKP isolates, collected from a tertiary hospital in eastern China. The 54 CRKP isolates were from 7 sequence types (STs) and belonged to 9 capsular K locus types, harboring bla KPC– 2 ( n = 49), bla NDM– 1 ( n = 5), and bla IMP– 4 ( n = 3). Among them, the epidemic KPC-2-producing ST11 strains were most predominant (88.9%). The 54 phages showed different host ranges from 7 to 52 CRKP isolates. The total host ranges of three phages can potentially cover all 54 CRKP isolates. Among the 54 phages, phage P545, classified as a member of Myoviridaes, order Caudovirales, had a relatively wide host range (96.3%), a short latent period of 20 min, and a medium burst size of 82 PFU/cell and was stably maintained at different pH values (4–10) and temperatures (up to 60°C). P545 showed the ability to inhibit biofilm formation and to degrade the mature biofilms. Taken together, the results of our study showed that the newly isolated phage P545 had a relatively wide host range, excellent properties, and antibacterial activity as well as antibiofilm activity against a clinical CRKP ST11 isolate, providing a promising candidate for future phage therapy applications.

Occurrence of Hypervirulent Klebsiella pneumoniae in Clinical Settings and Lytic Potential of Bacteriophages Against the Isolates

“…Consequently, the isolated phages have shown a broad host range against MDR K. pneumoniae isolates with 77% activity against MDR isolates. Similar results were also obtained in a recent study on MDR K. pneumoniae bacteriophages with a 96% host range against carbapenem MDR K. pneumoniae (30). However, bacteriophages isolated from Italy and Australia showed narrow host ranges.…”

“…Briefly, the hospital wastewater was collected in locally purchased 500 mL plastic bottles. All plastic bottles were then tightly closed and wrapped in sterile bags (strip plastic bags) to avoid contamination (30). All bottles were placed on the benchtop to allow the large debris to settle down for 1 to 3 hours.…”

Extended Spectrum Beta-Lactamase-Resistant Determinants among Carbapenem-Resistant Enterobacteriaceae from Beef Cattle in the North West Province, South Africa: A Critical Assessment of Their Possible Public Health Implications

“…Several studies have detected major ESBL genes ( blaTEM , blaSHV , blaCTX-M and blaOXA ) in CRE strains [ 11 ]. Given the fact that carbapenem antibiotics are considered as the last resort for treating infections caused by ESBL-producing strains, presence of carbapenemase and ESBL genes in CRE strains coupled with lack new therapeutic option is cause for concern [ 9 , 10 ].…”

Convergence of MCR-8.2 and chromosome-mediated resistance to colistin and tigecycline in an NDM-5-producing ST656 Klebsiella pneumoniae from a lung transplant patient

“…MLST analysis showed that the K. pneumoniae strain KP32558 was assigned to ST656, a rare ST type and firstly reported in China in 2012 (36). The frequently detected carbapenemase in these bacteria was KPC-2 (37) and NDM-1 (38). Our study represents the first report of the emergence of NDM-5 and MCR in ST656 K. pneumoniae clinical isolate.…”