A Case of Forearm Soft Tissue Infection Caused by Hypervirulent K. pneumoniae in an Otherwise Healthy 24-Year-Old Woman

Figures & data

Figure 1 (A and B) Redness and swelling of the forearm. (C and D) MRI revealed marked forearm muscle swelling, heterogeneous signal intensity and shadowing suggestive of gas.

Table 1 List of Primers Used for Detection of Hypervirulent K. pneumoniae Virulence Genes

Gene	Primer Sequence	Amplicon(bp)	Annealing Temperature (°C)
iucA	F: AATCAATGGCTATTCCCGCTG	239	59
	R: CGCTTCACTTCTTTCACTGACAGG
iroB	F: ATCTCATCATCTACCCTCCGCTC	235	59
	R: GGTTCGCCGTCGTTTTCAA
Ppeg-344	F: CTTGAAACTATCCCTCCAGTC	508	53
	R: CCAGCGAAAGAATAACCCC
prmpA	F: GAGTAGTTAATAAATCAATAGCAAT	332	50
	R: CAGTAGGCATTGCAGCA
prmpA2	F: GTGCAATAAGGATGTTACATTA	430	50
	R: GGATGCCCTCCTCCTG
K1	F: GTAGGTATTGCAAGCCATGC	1047	55
	R: GCCCAGGTTAATGAATCCGT
K2	F: GACCCGATATTCATACTTGACAGAG	641	57
	R: CCTGAAGTAAAATCGTAAATAGATGGC
K5	F: TGGTAGTGATGCTCGCGA	280	55
	R: CCTGAACCCACCCCAATC
K20	F: CGGTGCTACAGTGCATCATT	741	55
	R: GTTATACGATGCTCAGTCGC
K54	F CATTAGCTCAGTGGTTGGCT	881	55
	R GCTTGACAAACACCATAGCAG
K57	F: CTCAGGGCTAGAAGTGTCAT	1037	55
	R: CACTAACCCAGAAAGTCGAG

Figure 2 (A and B) Pus and gas were observed within the forearm musculature and intermuscular space during surgery. (C and D) Partial muscular necrosis and infection of the interosseous membrane and periosteum was observed.

Figure 3 The string test was performed using an inoculation loop to evaluate for hypermucoviscosity. (A) Formation of mucoviscous strings >5 mm in length was defined as a positive result. (B and C) Agarose gel electrophoresis revealed that the strain carried rmpA, rmpA2, iucA, iroB, and PEG-344 virulence genes and belonged to the K1 capsular serotype.

Figure 4 (A) Chest CT showing a lung abscess. (B) Abdominal CT showing a multilocular liver abscess.