C.-H. Liao

Clinical features, antimicrobial susceptibilities, and outcomes of Elizabethkingia meningoseptica (Chryseobacterium meningosepticum) bacteremia at a medical center in Taiwan, 1999-2006.

A total of 118 patients with Elizabethkingia meningoseptica bacteremia at a medical center in Taiwan from 1999 to 2006 were studied. Minimum inhibitory concentrations (MICs) of 99 preserved isolates were determined. The incidence (per 100,000 admissions) of E. meningoseptica bacteremia increased from 7.5 in 1996 to 35.6 in 2006 (pu2009=u20090.006). Among them, 84% presented with fever, 86% had nosocomial infections, and 60% had acquired the infection in intensive care units (ICUs). The most common underlying diseases were malignancy (36%) and diabetes mellitus (25%). Seventy-eight percent of patients had primary bacteremia, followed by pneumonia (9%), soft tissue infection, and catheter-related bacteremia (6%). Forty-five patients (38%) had polymicrobial bacteremia. Overall, the 14-day mortality was 23.4%. Multivariate analysis revealed E. meningoseptica bacteremia acquired in an ICU (pu2009=u20090.048, odds ratio [OR] 4.23) and presence of effective antibiotic treatment after the availability of culture results (pu2009=u20090.049, OR 0.31) were independent predictors of 14-day mortality. The 14-day mortality was higher among patients receiving carbapenems (pu2009=u20090.046) than fluoroquinolones or other antimicrobial agents. More than 80% of the isolates tested were susceptible to trimethoprim-sulfamethoxzole, moxifloxacin, and levofloxacin. The MIC50 and MIC90 of the isolates to tigecycline and doxycycline were both 4xa0μg/mL and 8xa0μg/ml, respectively.

Diagnostic performance of an enzyme-linked immunospot assay for interferon-γ in extrapulmonary tuberculosis varies between different sites of disease.

OBJECTIVESnTo evaluate diagnostic performance of an enzyme-linked immunospot assay for interferon-gamma (T SPOT-TB) in patients with suspected extrapulmonary tuberculosis (TB).nnnMETHODSnFrom January 2007 to December 2008, patients with suspected extrapulmonary TB were prospectively enrolled from 2 tertiary care hospitals.nnnRESULTSnA total of 138 patients with suspected extrapulmonary TB were enrolled; 50 patients had positive culture for Mycobacterium tuberculosis and 39 patients had probable TB. The sites of infection were lymph node (n = 20), pleura (n = 19), bone/joint (n = 15), urinary tract (n = 7), peritoneum (n = 7), meninges (n = 6), disseminated (n = 5), intestine (n = 3), pericardium (n = 2), skin (n = 2), throat (n = 1), neck (n = 1), and genitalia (n = 1). The overall sensitivity and specificity were 79.8% (71/89) and 81.6% (40/49). The sensitivity ranged from 100% for tuberculous meningitis, tuberculous pericarditis, and intestinal TB, 95% for lymphadenitis, to 42.9% for tuberculous peritonitis. The sensitivity of the T SPOT-TB assay was 70.6% in immunocompromised patients and 85.5% in immunocompetent patients (p = 0.09).nnnCONCLUSIONSnThe T SPOT-TB assay can be a useful tool for diagnosing extra-pulmonary TB in immunocompetent and immunocompromised patients, particularly for tuberculous meningitis, pericarditis, lymphadenitis, and intestinal TB.

Catheter-related bacteraemia and infective endocarditis caused by Kocuria species

We describe five patients with positive blood culture for Kocuria species. Three patients had catheter-related bacteraemia and one had infective endocarditis caused by Kocuria kristinae, and one had a K. marina isolate, which was considered to be a contaminant. Identification of the isolates was further confirmed by 16S rRNA gene sequence analysis. In conclusion, Kocuria species are an unusual cause of infection in immunocompromised patients. Accurate identification with molecular methods is imperative for the diagnosis of these unusual pathogens.

Risk factors for nosocomial infection during extracorporeal membrane oxygenation

An increasing number of patients receive extracorporeal membrane oxygenation (ECMO) for life support. This study aimed to investigate the incidence and risk factors for nosocomial infection in adult patients receiving ECMO. We reviewed the medical records of adult patients who received ECMO support for more than 72h at Far Eastern Memorial Hospital from 2001 to 2007. ECMO-related nosocomial infections were defined as infections occurring from 24h after ECMO initiation until 48h after ECMO discontinuation. There were 12 episodes of nosocomial infection identified in 10 of the 114 (8.77%) patients on ECMO, including four cases of pneumonia, three cases of bacteraemia, three surgical site infections and two urinary tract infections. The incidence of ECMO-related nosocomial infection was 11.92 per 1000 ECMO-days. The length of ECMO use and intensive care unit (ICU) stay were significantly different between patients with, and without, nosocomial infection (P<0.001). More than 10 days of ECMO use was associated with a significantly higher nosocomial infection rate (P=0.003). Gram-negative bacilli were responsible for 78% of the nosocomial infections. In the univariate analysis, the duration of ICU stay and duration of ECMO use were associated with nosocomial infection. In the multivariate analysis, only the duration of ECMO was independently associated with nosocomial infection (P=0.007). Overall, the only independent risk factor for ECMO-related nosocomial infection identified in this study was prolonged ECMO use.

Skin and soft-tissue infection caused by non-tuberculous mycobacteria in Taiwan, 1997-2008.

The aim of this study was to investigate the clinical, microbiological, and pathological characteristics and the outcomes of skin and soft-tissue infection (SSTI) caused by non-tuberculous mycobacteria (NTM). Medical records of 50 patients with SSTI caused by NTM identified from 2005 to 2008 and 63 patients previously reported in a medical centre from 1997 to 2004 were reviewed. The annual incidence (per 100,000 outpatients and in-patients) ranged from 0·57 in 2005, 0·38 in 2007, to 1·1 in 2008, with an average of 0·62/100,000. From 1997 to 2008, the average incidence was 1·39/100,000 patients. The average annual incidence of SSTI caused by NTM was 0·62/100,000 outpatients and in-patients during 2005 and 2008. Of the total of 113 patients identified during the 12-year period, patients infected with Mycobacterium fortuitum and M. marinum were younger than those infected with M. avium-intracellulare complex (MAC) (36 and 44 years vs. 55 years, P=0·004 and P=0·056, respectively), and were more likely to have previous invasive procedures than those infected with MAC and M. abscessus (81·8% and 72·0% vs. 27·8% and 54·8%, P=0·007), and less likely to have associated immunosuppression (9·1% and 24% vs. 66·7% and 45·2%, P=0·006). Granuloma was more often observed in immunocompetent patients (60·1% vs. 40%, P=0·019), and in M. marinum-infected specimens (78·3%). There were significant differences in the demographic and clinical features of patients with NTM SSTI, including immunosuppression, trauma experience, and depth of tissue infections.

Rapid identification of fungal pathogens in positive blood cultures using oligonucleotide array hybridization.

Identification of fungal species in positive blood cultures using conventional methods can be time-consuming, particularly for non-albicans Candida species, non-Candida yeasts, and moulds. An oligonucleotide array system targeting the internal transcribe spacer (ITS) 1 or 2 region of the rRNA genes was used to analyse prospectively 116 fungus-positive blood cultures [BACTEC Myco/F Lytic bottles (Becton-Dickinson Microbiology Systems, Sparks, MD, USA)] from 105 patients, and the results were compared with those obtained using conventional methods. A total of 124 yeast isolates and two mould isolates were identified; these microorganisms (isolate no.) included C. albicans (50), C. tropicalis (26), C. glabrata (18), C. parapsilosis (14), Cryptococcus neoformans (9), Trichosporon asahii (2), Rhodotorula mucilaginosa (2), Penicillium marneffei (2) and three other species. Multiple species fungaemia (MSF) was detected in ten samples as opposed to six detected using conventional methods. In two discrepant samples, antifungal susceptibility testing revealed that the additionally detected isolate had higher MICs of fluconazole. An isolate reported as Rhodotorula glutinis by the Vitek Yeast Biochemical Card (bioMérieux Vitek, Marcy lEtoile, France) was identified as R. mucilaginosa by the array and the identification by array hybridization was confirmed by sequence analysis of the ITS region. A test sensitivity of 100% was obtained. The test specificity was 100% according to examination of 57 blood samples containing non-target fungal species or bacterium only. From the time at which growth was detected in blood cultures, the entire identification procedure could be completed within 16-24 h.

Bacteremia caused by Brevundimonas species at a tertiary care hospital in Taiwan, 2000–2010

We investigated clinical and microbiological characteristics of 30 patients with Brevundimonas bacteremia treated at a tertiary care hospital in Taiwan during 2000–2010. All the 30 bacteria isolates were confirmed to the species level by 16S rRNA sequencing analysis. Minimum inhibitory concentrations (MICs) of 11 antimicrobial agents against these isolates were determined by the agar dilution method. Seventeen (57%) patients had underlying malignancy, 12 (40%) had undergone central catheter placement, and 13 (43%) had received chemotherapy within the previous three months. Eight (27%) patients had community-acquired bacteremia and the remaining 22 patients (73%) had healthcare-associated bacteremia. The overall 14-day and 30-day mortality rates were 13% and 17%, respectively. Among the 30 isolates, B. vesicularis constituted most commonly (nu2009=u200922, 63%), followed by B. nasdae (nu2009=u20095) and B. diminuta (nu2009=u20093). All isolates were susceptible to piperacillin-tazobactam and amikacin, while all were resistant to ciprofloxacin and colistin. Tigecycline (MICs at which 90% of isolates are inhibited [MIC90] was 0.12xa0mg/L) and doripenem (MIC90 of 1xa0mg/L) both possessed good in vitro activities. In conclusions, Brevundimonas should be considered a pathogen that can cause bacteremia in immunocompromised hosts. Piperacillin-tazobactam, amikacin, doripenem, and tigecycline exhibit good in vitro activities against these ciprofloxacin- and colistin-resistant Brevundimonas species.

Bacteraemia caused by Weissella confusa at a university hospital in Taiwan, 1997-2007

Human infections caused by Weissella confusa are rarely reported. Ten patients with bacteraemia caused by W. confusa who were treated at a tertiary-care hospital in Taiwan during 1997-2007 were studied. All isolates were initially misidentified as various Lactobacillus and Leuconostoc species by two commercial automated identification methods, and were confirmed to be W. confusa by 16S rRNA sequencing analysis. MICs of these isolates for ten antimicrobial agents were determined by the agar dilution method. The characteristics of these patients included underlying malignancy (n = 4), presence of a central catheter (n = 6), surgery within the previous 3 months (n = 4) and concomitant polymicrobial bacteraemia (n = 5, 50%). Mortality was directly attributed to bacteraemia in two patients. All isolates exhibited high trimethoprim-sulphamethoxazole and ceftazidime MICs (≥ 128 mg/L) and were inhibited by linezolid, daptomycin, ceftobiprole and tigecycline at 4, 0.12, 2 and 0.12 mg/L, respectively. In conclusion, W. confusa should be included in the list of organisms causing bacteraemia in immunocompromised hosts. Novel antibiotics, including daptomycin, moxifloxacin, doripenem and tigecycline, exert good activity against W. confusa.

Capsular serotypes and multilocus sequence types of bacteremic Klebsiella pneumoniae isolates associated with different types of infections

We investigated the epidemiology of different serotypes of Klebsiella pneumoniae isolates causing bacteremic liver abscess (LA) using multilocus sequence typing (MLST). MLST and molecular typing were performed for 41xa0K1 (19 LA), 37xa0K2 (5 LA), and 33 non-K1/K2 (6 LA) isolates that were derived from a previous one-year K. pneumoniae bacteremia cohort. Capsular serotypes and rmpA of these isolates were determined by polymerase chain reaction (PCR) methods. Among the 41xa0K1 isolates, 39 were ST23 and the remaining two isolates were ST23 single-locus variant. There were 11 STs among K2 isolates. ST65 was the most common (nu2009=u200910), followed by ST86, ST373, and ST375. Only ST65 (nu2009=u20093), ST373 (nu2009=u20091), and ST375 (nu2009=u20091) caused LA, and ST65 was a three-locus variant of ST23. For non-K1/K2 isolates, the ST types varied widely. ST218 (K57) was the most common type (nu2009=u20096, 18xa0%), and it was a single-locus variant of ST23 and caused two cases of LA. The existences of rmpA among serotypes varied (100xa0% for K1, 89xa0% for K2, and 55xa0% for non-K1/K2). For isolates causing LA, all of them were positive for rmpA. For non-K1/K2 isolates causing infections other than LA, the positivity of rmpA ranged from 0xa0% (biliary tree infection) to 67xa0% (pneumonia). In this one-year cohort, all K1 isolates were ST23 or its single-locus variants, but the composition of ST types among K2 isolates was quite variable. ST23 and its one- (ST1005 and ST218) and three-locus (ST65) variants comprised 80xa0% of isolates causing LA.

Clinical and pathological characteristics of mycobacterial tenosynovitis and arthritis

PurposeTo investigate the clinical characteristics and pathological features of patients with mycobacterial tenosynovitis and arthritis.MethodsAll patients with tenosynovitis and arthritis caused by Mycobacterium tuberculosis (MTB) and nontuberculous mycobacteria (NTM) who were treated at a medical center in Taiwan from 2001 to 2010 were analyzed.ResultsThirty-two patients with mycobacterial tenosynovitis and arthritis were identified. MTB was isolated exclusively from patients with arthritis of large joints (nxa0=xa011), while NTM were isolated from patients with arthritis of large joints (nxa0=xa04) and from those with tenosynovitis (nxa0=xa017). Among patients with tenosynovitis due to NTM, the most commonly found NTM were M. marinum (nxa0=xa07), M. intracellulare (nxa0=xa05), and M. abscessus (sensu stricto) (nxa0=xa02). Six of the seven patients with tenosynovitis due to M. marinum had suffered fishing-related injuries to the hands. All four patients with NTM arthritis had recurrent septic arthritis after surgery. NTM were isolated once from the debrided tissue specimens in three of these patients; the other patient died of systemic infection caused by M. intracellulare and multiple bacterial pathogens.ConclusionMycobacterial tenosynovitis should be considered in patients who present with indolent symptoms of chronic tenosynovitis. Complete clinical information, including history of trauma or joint replacement surgery and underlying systemic disease, is helpful in establishing an early diagnosis of the disease.