A 51-year-old male patient was admitted to our hospital with persistent fever for >20 days and blurred vision in his left eye. He had a history of untreated diabetes. The patient was aware of abdominal distention, but did not attend the hospital until he developed a fever of 39.5  C. At the community hospital, he was diagnosed with pneumonia, uncertain intestinal obstruction, uncertain vitreous hemorrhage, and diabetes, and was treated with empirical antibiotics. When his condition became critical, he was transferred to the local tertiary hospital for further treatment. Laboratory tests revealed a white blood cell count of 11.94 x 109/L (normal range = 4-9.5 x 109/L), a neutrophil count of 10.95 x 109/L (normal range = 2-6.5 x 109/L), serum albumin of 25.6 g/L (normal range = 40-55 g/L), serum creatinine of 123 mumol/L (normal range = 35-97 mumol/L), and random blood glucose of 22.4 mmol/L. Inflammatory markers were also measured, with results showing C-reactive protein exceeding 200 mg/L and procalcitonin of 29.82 mug/L. A computed tomographic scan showed multiple nodules in both lungs and intrahepatic cystic lesion with air accumulation (Figure 1), but imaging detected no intestinal obstruction. The clinician considered the patient's infection to be fatal, although the pathogen had not yet been identified. Meropenem was used for antimicrobial chemotherapy after blood was taken for bacterial culture. Treatment measures such as albumin infusion and nutritional support were implemented simultaneously.
However, the effect of treatment was poor. The patient's body temperature continued to rise to 40.4  C, which was attributed to the accumulation of pus in the liver abscess. Under the guidance of color ultrasound, the liver abscess was drained with percutaneous puncture, and 350 mL of brown pus was collected for bacterial culture. After the operation, the patient's body temperature dropped rapidly and his inflammatory indicators gradually decreased. However, sight in his left eye was still blurry. After consultation with an ophthalmologist, he was diagnosed with endogenous endophthalmitis (EE) (Figure 2A and C) and an emergency vitreous injection was performed. The pus in the vitreous cavity was also aspirated for bacteriological culture.
Five days after admission, the bacterial culture of the collected pus samples yielded Klebsiella pneumoniae. In vitro antimicrobial sensitivity tests showed that both strains were sensitive to all the drugs recommended by the Clinical & Laboratory Standards Institute (CLSI). Viscous strings from the colonies were both >5 mm in length, indicating positive string tests (Figure 3). A multilocus sequence typing (MLST) analysis of the isolated strains was performed with PCR amplification, as previously described. Seven housekeeping genes (gapA, infB, mdh, pgi, phoE, rpoB, and tonB) were amplified and sequenced. The multiple sequence information was compared with the MLST database and the strains were identified as belonging to ST25. The associated virulence genes and capsule serotypes were also determined, as previously described. The strains were positive for virulence genes iucA, rmpA2, rmpA, aerobactin, and entB. The serotype of the capsule was K2. Therefore, we diagnosed the patient with invasive syndrome secondary to ST25-K2 HvKp infection, with multiple infected lesions in the liver, lung, and eye.
Two weeks after admission, the patient had lost all vision in his left eye, accompanied by a very prominent headache and very high intraocular pressure. The ophthalmologist was consulted again and identified secondary glaucoma (Figure 2B). After a comprehensive evaluation and communication with the patient, he finally underwent left eye enucleation. The patient recovered and was discharged from the hospital on day 42 after admission. There was no recurrence of the disease at the 6-month follow-up.