A 51-year-old man presented to hospital with a 2-day history of pain, redness and vision loss in his right eye, and a 1-week history of fever, night sweats and 4.5 kg (10 lb) weight loss. Relevant medical history included type 2 diabetes and hypertension. He was taking no medications. He was born in Malaysia, had previously lived in Sri Lanka and moved to Canada 17 years before. He had not travelled recently.
On examination, he was febrile (38.7[degrees]C) and tachycardic (131 beats/min); his blood pressure and oxygen saturation were normal. He was alert and oriented. He had conjunctival injection in his right eye, a relative afferent pupillary defect and a 1.5 mm hypopyon, with his vision limited to perception of light only. This ophthalmologic examination was consistent with endogenous endophthalmitis. On chest auscultation, we heard crackles bilaterally. His abdominal examination was normal.
On investigation, he had elevated leukocyte (12.4 [normal 4-11] * [10.sup.9]/L), creatinine (111 [normal 44-106] [micro]mol/L), alkaline phosphatase (218 [normal 40-120] IU/L), bilirubin (37 [normal < 20) [micro]mol/L) and glycosylated hemoglobin (11.7% [target [less than or equal to] 7.0%]) levels. Gram staining of a vitreous aspirate showed Gram-negative bacilli. His chest radiograph showed bilateral nodular opacities.
We admitted the patient and started him on intravenous meropenem after collecting blood cultures. Ophthalmology also provided intravitreal ceftazidime for the patient's endophthalmitis. Computed tomography (CT) scans of his chest, abdomen and pelvis showed a 9.1 x 5.2 cm multiloculated liver abscess (Figure 1A), bilateral pulmonary nodules with central cavitation (Figure 1B) and bilateral renal hypodensities suggestive of pyelonephritis. Transthoracic echocardiogram showed no vegetations or substantial valvular abnormalities.
Within 24 hours of admission, the patient developed hypoxemic respiratory failure requiring intubation and transfer to the intensive care unit. Cultures of his blood, vitreous fluid, sputum, hepatic abscess aspirate and urine all showed growth of Klebsiella pneumoniae. Given the antibiotic susceptibilities, therapy was modified to intravenous ceftriaxone. The patient's initial abdominal ultrasound suggested the hepatic abscess was not amenable to drainage, but repeat imaging 72 hours later showed liquification and the abscess was drained percutaneously. He later developed acute respiratory distress syndrome and required prolonged mechanical ventilation.
The patient's clinical status gradually improved and he was extubated after 1 month. He was discharged to inpatient rehabilitation, 7 weeks after admission, on oral ciprofloxacin monotherapy. After a total of 3 months of antibiotic therapy, his hepatic and lung abscesses had resolved on repeat CT scans and antibiotics were discontinued. He was clinically stable 1 month after completion of antibiotic therapy. However, vision loss in his right eye persisted and the ophthalmology team deemed it irreversible.
K. pneumoniae isolates were consistent with a hypermucoviscous phenotype, based on the string test. Molecular testing, performed at the National Microbiology Laboratory in Winnipeg, Canada, found rmpA, iroB, iucA, ybtA, clbA and peg-344 genes, and the K1 capsular serotype, confirming disseminated infection due to hypervirulent K. pneumoniae.
Hypervirulent K. (hvKp) is an emerging strain of the encapsulated Gram-negative, bacillary bacterium K. pneumoniae. The strain carries integrated virulence factors,...