Haemophagocytic lymphohistiocytosis: an uncommon clinical presentation of tuberculosis.

Secondary haemophagocytic lymphohistiocytosis is a rare but fatal complication of tuberculosis. We describe two cases, and review the local and international experience on the management of this clinical entity. Prompt treatment with anti-tuberculous drugs forms the cornerstone of therapeutic success.

High mortality associated with Catabacter hongkongensis bacteremia.

Catabacter hongkongensis is a recently described catalase-positive, motile, anaerobic, nonsporulating, Gram-positive coccobacillus that was first isolated from blood cultures of four patients from Hong Kong and Canada. Although DNA sequences representing C. hongkongensis have been detected in environmental sources, only one additional case of human infection has been reported, in France. We describe five cases of C. hongkongensis bacteremia in Hong Kong, two presenting with sepsis, one with acute gangrenous perforated appendicitis, one with acute calculous cholecystitis, and one with infected carcinoma of colon. Three patients, with gastrointestinal malignancy, died during admission. All five isolates were catalase positive, motile, and negative for indole production and nitrate reduction and produced acid from arabinose, glucose, mannose, and xylose. They were unambiguously identified as C. hongkongensis by 16S rRNA gene analysis. Of the total of 10 reported cases of C. hongkongensis bacteremia in the literature and this study, most patients had underlying diseases, while two cases occurred in healthy young individuals with acute appendicitis. Six patients presented with infections associated with either the gastrointestinal or biliary tract, supporting the gastrointestinal tract as the source of bacteremia. C. hongkongensis bacteremia is associated with a poor prognosis, with a high mortality of 50% among reported cases, especially in patients with advanced malignancies. All reported isolates were susceptible to metronidazole. Identification of more C. hongkongensis isolates by 16S rRNA gene sequencing will help better define its epidemiology and pathogenesis.

Pneumococcal native aortic valve endocarditis with mycotic abdominal aortic aneurysm, paraspinal and iliopsoas abscesses and pneumonia revealing a multiple myeloma.

We report a rare case of multiple myeloma presenting with native aortic valve endocarditis with secondary embolic mycotic abdominal aortic aneurysm, contiguous paraspinal and iliopsoas abscesses, and pneumonia due to Streptococcus pneumoniae in a Chinese man. He was treated with aortic valve replacement, endovascular stenting of aneurysm, image-guided drainage of abscesses, and a 6-week course of endocarditic antibiotic therapy followed by chronic suppressive antibiotic therapy. Cases of multiple myeloma presenting with invasive pneumococcal infection were reviewed.

Capnocytophaga sputigena primary iliopsoas abscess.

Iliopsoas abscess is usually secondary to the spread of infection from a contiguous focus. Primary disease is uncommon, except in children where Staphylococcus aureus is the main pathogen. We report a 60-year-old woman who developed a primary iliopsoas abscess as a result of haematogenous spread of Capnocytophaga sputigena from a palatal fistula and chronic sinusitis due to previous treatment for nasopharyngeal carcinoma. Pyomyositis due to unusual and fastidious Gram-negative bacilli should be considered in patients with head and neck tumours who have previously received radiotherapy.

Epidemiology and clinical features of Shewanella infection over an eight-year period.

Shewanella is a rare human pathogen that can lead to fatal infections. However, clinical information about this bacterium remains scarce. In this study, we retrospectively reviewed all patients with laboratory isolates of Shewanella over an 8-y period to assess risk factors, clinical manifestations and outcome. Twenty-nine patients were identified. Shewanella was most commonly isolated from intra-abdominal specimens (48.2%), followed by skin and soft tissue specimens (27.6%), blood (13.8%) and sputum (10.3%). Malignancy, hepatobiliary disease and diabetes mellitus were common underlying diseases. The overall 30-day mortality rate was 20.6%. Shewanella was considered a definite causative pathogen in 7 patients, and a recurrent infection occurred in 2 patients. Colonization of the biliary tract was common. Among co-isolated pathogens, the enteric flora was most represented. All isolates were susceptible to ceftazidime and aminoglycosides, but 1 isolate was resistant to imipenem. In conclusion, Shewanella may become a colonizing bacterium, subsequently causing invasive diseases in patients with an underlying disease.

Outbreak of intestinal infection due to Rhizopus microsporus.

Sinopulmonary and rhinocerebral zygomycosis has been increasingly found in patients with hematological malignancies and bone marrow transplantation, but intestinal zygomycosis remains very rare in the literature. We investigated an outbreak of intestinal infection due to Rhizopus microsporus in 12 patients on treatment for hematological malignancies over a period of 6 months in a teaching hospital. The intake of allopurinol during hospitalization (P < 0.001) and that of commercially packaged ready-to-eat food items in the preceding 2 weeks (P < 0.001) were found to be independently significant risk factors for the development of intestinal zygomycosis. A total of 709 specimens, including 378 environmental and air samples, 181 food samples, and 150 drug samples, were taken for fungal culture. Among them, 16 samples of allopurinol tablets, 3 prepackaged ready-to-eat food items, and 1 pair of wooden chopsticks were positive for Rhizopus microsporus, which was confirmed by ITS1-5.8S-ITS2 rRNA gene cluster (internal transcribed spacer [ITS]) sequencing. The mean viable fungal counts of allopurinol obtained from wards and pharmacy were 4.22 x 10(3) CFU/g of tablet (range, 3.07 x 10(3) to 5.48 x 10(3)) and 3.24 x 10(3) CFU/g of tablet (range, 2.68 x 10(3) to 3.72 x 10(3)), respectively, which were much higher than the mean count of 2 x 10(2) CFU/g of food. Phylogenetic analysis by ITS sequencing showed multiple clones from isolates of contaminated allopurinol tablets and ready-to-eat food, of which some were identical to patients' isolates, and with one isolate in the cornstarch used as an excipient for manufacture of this drug. We attempted to type the isolates by random amplification of polymorphic DNA analysis, with limited evidence of clonal distribution. The primary source of the contaminating fungus was likely to be the cornstarch used in the manufacturing of allopurinol tablets or ready-to-eat food. Rhizopus microsporus is thermotolerant and can multiply even at 50 degrees C. The long holding time of the intermediates during the manufacturing process of allopurinol amplified the fungal load. Microbiological monitoring of drugs manufactured for highly immunosuppressed patients should be considered.