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Three bacterial strains, HKU70 T , HKU71 T and HKU72 T , were isolated from the conjunctival swab, blood and sputum samples of three patients with conjunctivitis, bacteraemia and respiratory infection, respectively, in Hong Kong. The three strains were aerobic, Gram-stain positive, catalase-positive, non-sporulating and non-motile bacilli and exhibited unique biochemical profiles distinguishable from currently recognized Tsukamurella species. 16S rRNA, secA , rpoB and groEL gene sequence analyses revealed that the three strains shared 99.6-99.9, 94.5-96.8, 95.7-97.8 and 97.7-98.9 % nucleotide identities with their corresponding closest Tsukamurella species respectively. DNA-DNA hybridization confirmed that they were distinct from other known species of the genus Tsukamurella (26.2±2.4 to 36.8±1.2 % DNA-DNA relatedness), in line with results of in silico genome-to-genome comparison (32.2-40.9 % Genome-to-Genome Distance Calculator and 86.3-88.9 % average nucleotide identity values]. Fatty acids, mycolic acids, cell-wall sugars and peptidoglycan analyses showed that they were typical of members of Tsukamurella . The G+C content determined based on the genome sequence of strains HKU70 T , HKU71 T and HKU72 T were 69.9, 70.2 and 70.5 mol%, respectively. Taken together, our results supported the proposition and description of three new species, i.e. Tsukamurella sputi HKU70 T (=JCM 33387 T =DSM 109106 T ) sp. nov., Tsukamurella asaccharolytica HKU71 T (=JCM 33388 T =DSM 109107 T ) sp. nov. and Tsukamurella conjunctivitidis HKU72 T (=JCM 33389 T =DSM 109108 T ) sp. nov.

Unlike Elizabethkingia meningoseptica, the clinical importance of E. anophelis is poorly understood. We determined the clinical and molecular epidemiology of bacteremia caused by Elizabethkingia-like species from five regional hospitals in Hong Kong. Among 45 episodes of Elizabethkingia-like bacteremia, 21 were caused by Elizabethkingia, including 17 E. anophelis, three E. meningoseptica and one E. miricola; while 24 were caused by other diverse genera/species, as determined by 16S rRNA gene sequencing. Of the 17 cases of E. anophelis bacteremia, 15 (88%) were clinically significant. The most common diagnosis was pneumonia (n = 5), followed by catheter-related bacteremia (n = 4), neonatal meningitis (n = 3), nosocomial bacteremia (n = 2) and neutropenic fever (n = 1). E. anophelis bacteremia was commonly associated with complications and carried 23.5% mortality. In contrast, of the 24 episodes of bacteremia due to non-Elizabethkingia species, 16 (67%) were clinically insignificant. Compared to non-Elizabethkingia bacteremia, Elizabethkingia bacteremia was associated with more clinically significant infections (P < 0.01) and positive cultures from other sites (P < 0.01), less polymicrobial bacteremia (P < 0.01), and higher complication (P < 0.05) and mortality (P < 0.05) rates. Elizabethkingia bacteremia is predominantly caused by E. anophelis instead of E. meningoseptica. Elizabethkingia bacteremia, especially due to E. anophelis, carries significant morbidity and mortality, and should be considered clinically significant unless proven otherwise.

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.

We describe a case of Solobacterium moorei bacteremia in a 43-year-old woman presenting with acute proctitis complicating radiotherapy for cervical carcinoma. Phenotypic tests failed to identify the bacterium, which was subsequently identified by 16S rRNA gene sequencing. 16S rRNA gene sequencing could help better define the pathogenicity of S. moorei.

In a retrospective study designed to gather information in a region with high antimicrobial resistance, the outcomes of 216 episodes of laboratory-confirmed pneumococcal bacteremia treated in Hong Kong between 1995 and 2001 were assessed. The patients had a mean age (+/-standard deviation) of 40+/-33.7 years. In all patients, the clinical diagnosis was confirmed by isolation of Streptococcus pneumoniae from blood (n=216), cerebrospinal fluid (n=7) and/or other sterile sites (n=12). Penicillin nonsusceptibility was found in 37.5% of the isolates (20.8% intermediate and 16.7% resistant). Penicillin nonsusceptibility was not a risk factor for inpatient mortality (p=0.7), nor did it affect duration of fever (p=0.4), requirement for intensive care unit admission (p=0.4) or development of suppurative complications (p=0.2). Advanced age (OR 11.3, 95%CI 4.5-28.2, p<0.01), critical illness (OR 11.3, 95%CI 4.5-28.2, p<0.001) and discordant therapy (OR 4.3, 95%CI 1.7-10.9, p<0.002) involving agents with poor anti-pneumococcal activity (but not penicillins and broad-spectrum beta-lactam agents) were significantly associated with mortality.

Traditionally, the identification, epidemiology and spectrum of clinical diseases caused by Granulicatella adiacens and Abiotrophia defectiva are dependent upon their phenotypic characterization. During a 6-year period (July 1995-June 2001), seven and two alpha-haemolytic streptococci were identified as G. adiacens and A. defectiva, respectively, by 16S rRNA gene sequencing. Three patients with haematological malignancies and neutropenic fever had primary bacteraemia. Three patients with valvular problems or congenital heart disease had infective endocarditis. A patient with ischemic heart disease and cerebrovascular accident had infected aortic atheroma with dissection. A patient with recurrent pyogenic cholangitis had acute cholangitis and a patient with polypoid cystitis and benign prostatic hypertrophy had acute prostatitis. Four of the nine patients died, including all three with G. adiacens infective endocarditis or infected atheroma. For the seven G. adiacens isolates, the API 20 STREP system successfully identified one and five isolates as G. adiacens with >95 % and 80-90 % confidence, respectively, whereas the Vitek System (GPI) and ATB Expression system (ID32 STREP) successfully identified none and one isolate as G. adiacens. Of the two A. defectiva isolates, none of the three systems successfully identified either of them as A. defectiva. 16S rRNA gene sequencing is the technique of choice for identifying G. adiacens and A. defectiva, and early surgical intervention should be considered when G. adiacens endocarditis is diagnosed.