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 41 K1 (19 LA), 37 K2 (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 41 K1 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 (n = 10), followed by ST86, ST373, and ST375. Only ST65 (n = 3), ST373 (n = 1), and ST375 (n = 1) 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 (n = 6, 18 %), and it was a single-locus variant of ST23 and caused two cases of LA. The existences of rmpA among serotypes varied (100 % for K1, 89 % for K2, and 55 % 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 0 % (biliary tree infection) to 67 % (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 80 % of isolates causing LA.

Direct observation therapy with appropriate treatment regimens was associated with a decline in second-line drug-resistant tuberculosis in Taiwan.

The resistance of Mycobacterium tuberculosis (MTB) to second-line drugs (SLDs) is growing worldwide; however, associations between the appropriateness of treatment for tuberculosis (TB) and whether the directly observed treatment, short course (DOTS)/DOTS-plus programs had an impact on the prevalence of SLD-resistant MTB are still uncertain. We performed a retrospective analysis of resistance profiles among MTB isolates obtained from 6,035 consecutive patients from 2004 to 2011 at two TB referral hospitals in Taiwan. There was a significant decrease (all p-values <0.01) in the prevalence of MTB isolates that were resistant to fluoroquinolones, injectable SLDs, and orally administered SLDs, and multidrug-resistant (MDR) and extensively drug-resistant (XDR) MTB isolates over time. There was a significant increase in the coverage rate of DOTS/DOTS-plus programs and that of administering appropriate first-line and second-line regimens (all p < 0.01). Compared with isoniazid-susceptible isolates, high-level (1.0 mg/L) isoniazid-resistant and MDR isolates showed extensive cross resistance to ofloxacin (5.9%, p < 0.01 and 33.6%, p < 0.01), levofloxacin (9.6%, p < 0.01 and 38.1%, p < 0.01), moxifloxacin (11.1%, p < 0.01 and 26.5%, p < 0.01), kanamycin (6.8 %, p < 0.01 and 16.7 %, p < 0.01), ethionamide (6.4%, p < 0.01 and 16.2%, p < 0.01), and para-aminosalicylic acid (13.1%, p < 0.01 and 20.4%, p < 0.01), but not to capreomycin (2.0%, p = 0.06 and 1.6%, p = 0.08). The decline in prevalence of resistance to SLDs was negatively correlated with the rise in rates of administering appropriate regimens as well as the DOTS/DOTS-plus programs, but not with the increase in usage of second-line regimens. The implementation of DOTS/DOTS-plus programs with appropriate regimens was associated with a decrease in the prevalence of SLD-resistant and XDR TB.

Trends in the susceptibility of commonly encountered clinically significant anaerobes and susceptibilities of blood isolates of anaerobes to 16 antimicrobial agents, including fidaxomicin and rifaximin, 2008-2012, northern Taiwan.

We investigated the antimicrobial resistance trends and profiles of clinical anaerobic isolates in northern Taiwan. Trends in the susceptibility of five commonly encountered clinical anaerobic isolates to seven agents from 2008 to 2012 were measured using the Cochran-Armitage trend test. The minimum inhibitory concentrations (MICs) of 16 antimicrobial agents, including fidaxomicin and rifaximin, against anaerobic blood isolates from two medical centers were determined using the agar dilution method. During the study period, susceptibility data on 11,105 isolates were evaluated. Metronidazole and chloramphenicol retained excellent activities. Around 20-30 % of isolates of Bacteroides and Prevotella species were resistant to ampicillin-sulbactam, cefmetazole, flomoxef, and clindamycin. Of the 507 tested blood isolates, the rates of resistance to commonly used agents were much higher, namely, 16.2 % for amoxicillin-clavulanate, 15.6 % for ampicillin-sulbactam, 24.7 % for cefmetazole, and 36.1 % for clindamycin. Notably, 13.5 % of B. fragilis isolates were resistant to ertapenem. Also, 15.2 % of B. uniformis, 17.2 % of other Bacteroides species, 14.3 % of Prevotella species, and 14 % of Clostridium other than C. perfringens isolates were resistant to moxifloxacin. Cefoperazone-sulbactam was active against most isolates, except for Clostridium species other than perfringens (resistance rate, 18.6 %). Fidaxomicin exerted poor activities against most anaerobes tested (MIC90 of >128 µg/ml for B. fragilis and all isolates), except for C. perfringens (MIC90 of 0.03 µg/ml) and Peptostreptococcus micros (MIC90 of 2 µg/ml). However, rifaximin showed a wide range of susceptibilities against the tested anaerobes (MIC90 of 0.5 µg/ml for B. fragilis). The emergence of resistance to ertapenem and moxifloxacin among bacteremic anaerobes highlights the need for continuous monitoring.

Bacteria killing nanotechnology Bio-Kil effectively reduces bacterial burden in intensive care units.

A contaminated hospital environment has been identified as an important reservoir of pathogens causing healthcare-associated infections. This study is to evaluate the efficacy of bacteria killing nanotechnology Bio-Kil on reducing bacterial counts in an intensive care unit (ICU). Two single-bed rooms (S-19 and S-20) in the ICU were selected from 7 April to 27 May 2011. Ten sets of new textiles (pillow cases, bed sheets, duvet cover, and patient clothing) used by patients in the two single-bed rooms were provided by the sponsors. In the room S-20, the 10 sets of new textiles were washed with Bio-Kil; the room walls, ceiling, and air-conditioning filters were treated with Bio-Kil; and the surfaces of instruments (respirator, telephone, and computer) were covered with Bio-Kil-embedded silicon pads. Room S-19 served as the control. We compared the bacterial count on textiles and environment surfaces as well as air samples between the two rooms. A total of 1,364 samples from 22 different sites in each room were collected. The mean bacterial count on textiles and environmental surfaces in room S-20 was significantly lower than that in room S-19 (10.4 vs 49.6 colony-forming units [CFU]/100 cm(2); P < 0.001). Room S-20 had lower bacterial counts in air samples than room S-19 (33.4-37.6 vs 21.6-25.7 CFU/hour/plate; P < 0.001). The density of microbial isolations was significantly greater among patients admitted to room S-19 than those to room S-20 (9.15 vs 5.88 isolates per 100 patient-days, P < 0.05). Bio-Kil can significantly reduce bacterial burden in the environment of the ICU.

Risk factors for levofloxacin-nonsusceptible Streptococcus pneumoniae in community-acquired pneumococcal pneumonia: a nested case-control study.

This study was performed to evaluate the clinical features of community-onset levofloxacin-nonsusceptible pneumococcal pneumonia and to identify risk factors for levofloxacin resistance. Using the database of a surveillance study of community-acquired pneumococcal infections in Asian countries, we conducted a nested case-control study to identify risk factors for levofloxacin-nonsusceptible S. pneumoniae in community-acquired pneumonia in adults. Of 981 patients with pneumococcal pneumonia, 46 (4.7 %) had levofloxacin-nonsusceptible S. pneumoniae, of whom 39 evaluable cases were included in the analysis. All cases were from Korea, Taiwan, and Hong Kong. Among patients with levofloxacin-susceptible S. pneumoniae, 490 controls were selected based on patient country. Of the 39 cases of levofloxacin-nonsusceptible pneumococcal pneumonia, 23 (59.0 %) were classified as healthcare-associated, while 164 (33.5 %) of the 490 controls of levofloxacin-susceptible S. pneumoniae (P = 0.001) were classified as healthcare-associated. Multivariate analysis showed that previous treatment with fluoroquinolones, cerebrovascular disease, and healthcare-associated infection were significantly associated with levofloxacin-nonsusceptible pneumococcal pneumonia (all P < 0.05). Levofloxacin-nonsusceptible pneumococci pose an important new public health threat in our region, and more information on the emergence and spread of these resistant strains will be necessary to prevent spread throughout the population.

Clinical characteristics and outcomes of patients with pleural infections due to Stenotrophomonas maltophilia at a medical center in Taiwan, 2004-2012.

Stenotrophomonas maltophilia can cause various clinical diseases; however, pleural infections due to S. maltophilia are rare. We evaluated the clinical characteristics and outcomes of patients with pleural infections (complicated parapneumonic effusion or empyema) due to S. maltophilia who were treated at a medical center in Taiwan from 2004 to 2012. During the study period, 40 patients were treated for pleural infections due to S. maltophilia. The incidence of S. maltophilia pleural infections ranged from 2.66 per 1,000,000 patient-days in 2009 to 12.44 per 1,000,000 patient-days in 2011. Most of the patients with S. maltophilia pleural infections were immunocompromised male adults and all of the infections were acquired in healthcare settings. The majority of patients had polymicrobial pleural infections (n = 31, 77.5 %) and the most common pathogen was Pseudomonas aeruginosa (n = 12). The causes of pleural infections due to S. maltophilia were pneumonia due to S. maltophilia in two patients (5 %), post-surgical/tube thoracostomy in 26 (65 %) patients, and fistula (bronchopleural, esophagopleural and biliopleural) in 12 (30 %) patients. The 14-day and 30-day mortality rates were 32.5 % and 42.5 %, respectively. Pleural infections due to S. maltophilia are most commonly the result of surgical procedures, thoracostomy, and underlying fistulas. These infections are associated with a high mortality rate, especially among immunocompromised patients.

Trends in the susceptibility of methicillin-resistant Staphylococcus aureus to nine antimicrobial agents, including ceftobiprole, nemonoxacin, and tyrothricin: results from the Tigecycline In Vitro Surveillance in Taiwan (TIST) study, 2006-2010.

This study investigated the in vitro susceptibilities of methicillin-resistant Staphylococcus aureus (MRSA) to nine antimicrobial agents in Taiwan. A total of 1,725 isolates were obtained from 20 hospitals throughout Taiwan from 2006 to 2010. The minimum inhibitory concentrations (MICs) of the nine agents were determined by the agar dilution method. The MICs of mupirocin and tyrothricin were determined for 223 MRSA isolates collected from 2009 to 2010. For vancomycin, 99.7 % were susceptible; however, 30.0 % (n = 517) exhibited MICs of 2 µg/ml and 0.3 % (n = 6) demonstrated intermediate susceptibility (MICs of 4 µg/ml). Nearly all isolates (≥ 99.9 %) were susceptible to teicoplanin, linezolid, and daptomycin. The MIC90 values were 2 µg/ml for ceftobiprole and 1 µg/ml for nemonoxacin. The MIC90 values of mupirocin and tyrothricin were 0.12 and 4 µg/ml, respectively. MIC creep was noted for daptomycin during this period, but not for vancomycin, teicoplanin, linezolid, or tigecycline. For isolates with vancomycin MICs of 2 µg/ml, the MIC90 values were 2 µg/ml for teicoplanin, 0.5 µg/ml for daptomycin, and 0.5 µg/ml for tigecycline. Those values were four- to eight-fold higher than those among isolates with vancomycin MICs of 0.5 µg/ml (2, 0.06, and 0.12 µg/ml, respectively). Of the nine MRSA isolates exhibiting non-susceptibility to vancomycin (n = 6), teicoplanin (n = 1), daptomycin (n = 2), or tigecycline (n = 1), all had different pulsotypes, indicating the absence of intra-hospital or inter-hospital spread. The presence of a high proportion of MRSA isolates with elevated MICs (2 µg/ml) and MIC creep of daptomycin might alert clinicians on the therapy for serious MRSA infections in Taiwan.

Mycobacterial bone marrow infections at a medical centre in Taiwan, 2001-2009.

Mycobacterial bone marrow (BM) infection is the most common diagnosis established by BM examinations for fever of unknown origin. In this study, clinical features and outcomes of patients who fulfilled the criteria for BM infection due to Mycobacterium tuberculosis (MTB) and non-tuberculous mycobacteria (NTM) at a medical centre in Taiwan from 2001 to 2009 were investigated. The BM histopathological findings were also analysed. A total of 24 patients (16 men, eight women) with mycobacterial BM infections were found. Of these, nine (38%) were positive for human immunodeficiency virus (HIV) and six (25%) had no pre-existing immunocompromised conditions. MTB isolates were obtained from 11 (46%) patients and NTM species were isolated from 10 (42%) patients, including M. avium complex (MAC, n = 7) and M. kansasii (n = 3). Patients with MTB infections were significantly older than those with NTM infections (60·5 vs. 47·7 years, P = 0·043) and were less likely to have a positive BM culture (45% vs. 100%, P = 0·012). The 90-day survival rates for MTB and NTM BM infections were 68% and 60%, respectively (P = 0·61). In addition, the presence of BM granulomas was significantly more common in patients with MTB BM infections than in those with NTM infections (82% vs. 30%, P = 0·030). In Taiwan, the importance of NTM was not inferior to MTB and besides MAC, M. kansasii might be an important pathogen in non-HIV-infected patients. The presence of BM granulomas and caseation provides valuable information regarding early treatment pending culture results.

Changing aetiology of healthcare-associated bloodstream infections at three medical centres in Taiwan, 2000-2011.

This multicentre surveillance study was conducted to investigate the trends in incidence and aetiology of healthcare-associated bloodstream infections (HCA-BSIs) in Taiwan. From 2000 to 2011 a total of 56 830 HCA-BSIs were recorded at three medical centres, and coagulase-negative staphylococci (CoNS) were the most common pathogens isolated (n = 9465, 16·7%), followed by E. coli (n = 7599, 13·4%). The incidence of all HCA-BSIs in each and all hospitals significantly increased over the study period owing to the increase of aerobic Gram-positive cocci and Enterobacteriaceae by 4·2% and 3·6%, respectively. Non-fermenting Gram-negative bacteria, Bacteroides spp. and Candida spp. also showed an increase but there was a significant decline in the numbers of methicillin-resistant S. aureus. In conclusion, the incidence of HCA-BSIs in Taiwan is significantly increasing, especially for Enterobacteriaceae and aerobic Gram-positive cocci.

Dissemination of meticillin-resistant Staphylococcus aureus sequence type 8 (USA300) in Taiwan.

BACKGROUND: In Taiwan, sequence type (ST) 239 and ST59 were two major clones among meticillin-resistant Staphylococcus aureus (MRSA) clinical isolates in the past two decades. USA300 (ST8) prevailed in the Americas but not in outside areas. Recently USA300 (ST8) emerged and was increasingly identified in Taiwan; we thus conducted an island-wide study to explore the role of USA300 among MRSA isolates. METHODS: One hundred MRSA bloodstream isolates identified in 2020 from each of the six participating hospitals in Taiwan were collected and characterized. The first 10 ST8 isolates from each hospital were further analysed by whole-genome sequencing. RESULTS: Of the 590 confirmed MRSA isolates, a total of 22 pulsotypes and 21 STs were identified. The strain of pulsotype AI/ST8 was the most common lineage identified, accounting for 187 isolates (31.7%) and dominating in five of six hospitals, followed by pulsotype A/ST239 (14.7%), pulsotype C/ST59 (13.9%) and pulsotype D/ST59 (9.2%). Of the 187 pulsotype AI/ST8 isolates, 184 isolates were characterized as USA300 and clustered in three major sub-pulsotypes, accounting for 78%. Ninety per cent of the 60 ST8 isolates for whole-genome sequencing were clustered in three major clades. CONCLUSIONS: In 2020, USA300 became the most common clone of MRSA in Taiwan, accounting for >30% of MRSA bloodstream isolates island wide. Most of USA300 isolates circulating in Taiwan might have been imported on multiple occasions and evolved into at least three successful local clades. MRSA USA300 has successfully established its role in Taiwan, an area outside of the Americas.

Clinical outcomes of tigecycline alone or in combination with other antimicrobial agents for the treatment of patients with healthcare-associated multidrug-resistant Acinetobacter baumannii infections.

Tigecycline (TG) has been shown to be active in vitro against Acinetobacter baumannii, although data on the clinical efficacy of TG alone or in combination for the treatment of infections due to multidrug-resistant A. baumannii (MDRAB) remain limited. The purpose of this study was to investigate the clinical outcomes of patients with healthcare-associated infections (HAIs) caused by MDRAB who were treated with imipenem/cilastatin and sulbactam, and TG alone or in combination with other antibiotics. A total of 386 patients with HAIs caused by MDRAB were retrospectively analyzed and grouped into TG and non-TG groups, depending on whether they received TG treatment. Of the 266 patients in the TG group, 108 were treated with TG alone and 158 were treated with TG in combination with ceftazidime, ceftriaxone, piperacillin/tazobactam, or a carbapenem. All 120 patients in the non-TG group were treated with imipenem/cilastatin and sulbactam. The primary outcome measure was 30-day mortality after TG treatment and the secondary outcome was clinical outcome. There were no significant differences in survival rates between the two groups. However, the rate of unfavorable outcome was significantly lower (p < 0.05) among patients in the TG group than among patients in the non-TG group. The most significant predictor of unfavorable outcome was sepsis, whereas TG treatment and microbial eradication were the most significant predictors of favorable outcomes. Our study represents the largest study of patients with MDRAB infection treated with TG and expands our understanding of the role of TG therapy alone or in combination with other agents for the treatment of HAI caused by MDRAB.

Biliary tract infections caused by Aeromonas species.

This study investigated the clinical and microbiological characteristics of patients with Aeromonas infections of the biliary tract. Patients with bile cultures positive for Aeromonas species during the period July 2004 to December 2011 were identified from a computerized database of a hospital in Taiwan. Patients with Aeromonas infections of the biliary tract were further identified. During the study period, a total of 1,142 isolates of Aeromonas species were obtained from 750 patients. Of those patients, 91 (12.1 %) had Aeromonas infections of the biliary tract. The annual incidence (episodes per 10,000 patient-days) of biliary tract infections caused by all Aeromonas species was 0.31 in 2007, 0.12 in 2010, and 0.27 in 2011. A. hydrophila was the most common species isolated (n = 41, 45.1 %), followed by A. caviae (n = 30, 33.0 %), A. veronii biovar sobria (n = 15, 16.5 %), and A. veronii biovar veronii (n = 5, 5.5 %). The majority of patients (n = 77, 84.6 %) had polymicrobial infections. Hepatobiliary stones (n = 50, 54.9 %) and hepatobiliary cancer (n = 38, 41.8 %) were the most common underlying diseases, followed by diabetes mellitus (n = 29, 31.9 %) and liver cirrhosis (n = 7, 7.7 %). The in-hospital mortality rate was 8.8 %. Infection-related mortality was associated with underlying immunocompromised condition (p = 0.044) and use of mechanical ventilation (p = 0.004), but was not associated with inappropriate antibiotic usage or concomitant bacteremia (n = 8, 8.8 %). In conclusion, biliary tract infections caused by Aeromonas species are not uncommon and can develop in both immunocompromised and immunocompetent patients; however, patients with underlying hepatobiliary diseases are particularly susceptible to these infections.

Skin and soft-tissue infections caused by Aeromonas species.

This study investigated the clinical characteristics of patients with skin and soft-tissue infections (SSTIs) due to Aeromonas species. Patients with SSTIs caused by Aeromonas species during the period from January 2009 to December 2011 were identified from a computerized database of a regional hospital in southern Taiwan. The medical records of these patients were retrospectively reviewed. A total of 129 patients with SSTIs due to Aeromonas species were identified. A. hydrophila (n = 77, 59.7 %) was the most common pathogen, followed by A. veronii biovar sobria (n = 22, 17.1 %), A. veronii biovar veronii (n = 20, 15.5 %), A. caviae (n = 9, 7.0 %), and A. schubertii (n = 1, 0.8 %). The most common isolates obtained from patients with polymicrobial infections were Klebsiella species (n = 33), followed by Enterococcus spp. (n = 24), Enterobacter spp. (n = 21), Escherichia coli (n = 17), Staphylococcus spp. (n = 17), Streptococcus spp. (n = 17), and Acinetobacter spp. (n = 15). Liver cirrhosis and concomitant bacteremia were more common among patients with monomicrobial Aeromonas SSTIs than among patients with polymicrobial SSTIs. Nine (7 %) patients required limb amputations. The in-hospital mortality rate was 1.6 %. In conclusion, Aeromonas species should be considered as important causative pathogens of SSTIs, and most infections are polymicrobial. In addition, the clinical presentation differs markedly between patients with monomicrobial and those with polymicrobial Aeromonas SSTIs.

Pneumonia caused by Aeromonas species in Taiwan, 2004-2011.

We investigated the clinical characteristics of patients with pneumonia caused by Aeromonas species. Patients with pneumonia caused by Aeromonas species during the period 2004 to 2011 were identified from a computerized database of a regional hospital in southern Taiwan. The medical records of these patients were retrospectively reviewed. Of the 84 patients with pneumonia due to Aeromonas species, possible Aeromonas pneumonia was diagnosed in 58 patients, probable Aeromonas pneumonia was diagnosed in 18 patients, and pneumonia due to Aeromonas was conclusively diagnosed in 8 patients. Most of the cases of Aeromonas pneumonia developed in men and in patients of advanced age. A. hydrophila (n = 50, 59.5 %) was the most common pathogen, followed by A. caviae (n = 24, 28.6 %), A. veronii biovar sobria (n = 7, 8.3 %), and A. veronii biovar veronii (n = 3, 3.6 %). Cancer (n = 37, 44.0 %) was the most common underlying disease, followed by diabetes mellitus (n = 27, 32.1 %). Drowning-associated pneumonia developed in 6 (7.1 %) patients. Of 47 patients who were admitted to the intensive care ward, 42 patients developed acute respiratory failure and 24 of those patients died. The overall in-hospital mortality rate was significantly associated with liver cirrhosis, cancer, initial presentation of shock, and usage of mechanical ventilation. In conclusion, Aeromonas species should be considered as one of the causative pathogens of severe pneumonia, especially in immunocompromised patients, and should be recognized as a cause of drowning-associated pneumonia. Cirrhosis, cancer, and shock as the initial presenting symptom are associated with poor outcome.

Clinical and pathological characteristics of mycobacterial tenosynovitis and arthritis.

PURPOSE: To investigate the clinical characteristics and pathological features of patients with mycobacterial tenosynovitis and arthritis. METHODS: All 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. RESULTS: Thirty-two patients with mycobacterial tenosynovitis and arthritis were identified. MTB was isolated exclusively from patients with arthritis of large joints (n = 11), while NTM were isolated from patients with arthritis of large joints (n = 4) and from those with tenosynovitis (n = 17). Among patients with tenosynovitis due to NTM, the most commonly found NTM were M. marinum (n = 7), M. intracellulare (n = 5), and M. abscessus (sensu stricto) (n = 2). 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. CONCLUSION: Mycobacterial 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.

Association of levofloxacin resistance with mortality in adult patients with invasive pneumococcal diseases: a post hoc analysis of a prospective cohort.

OBJECTIVE: This study was conducted to identify risk factors for mortality and to evaluate the impact of antimicrobial resistance on outcome in adult patients with invasive pneumococcal disease (IPD). METHODS: A post hoc analysis of an observational cohort study on community-acquired pneumococcal infections was conducted and a total of 136 adult patients with IPD were analyzed in this study. RESULTS: Pneumonia was the most common type of infection (n = 84, 61.8 %), followed by primary bacteremia (n = 15, 11.0 %) and meningitis (n = 15, 11.0 %). One hundred and three patients (75.7 %) had concomitant pneumococcal bacteremia. The overall 30-day mortality rate was 26.5 % (36/136), and factors associated with 30-day mortality were corticosteroid use, presentation with septic shock, and development of acute respiratory distress syndrome (ARDS) (all P < 0.05). While penicillin and erythromycin resistance were associated with a lower mortality, an association between levofloxacin resistance and increased mortality was found in the univariate analysis; however, statistical significance was not reached (P = 0.083). Multivariable analysis showed that presentation with septic shock, corticosteroid use, development of ARDS, and levofloxacin resistance were independent factors associated with 30-day mortality. Of the five patients with IPD caused by levofloxacin-resistant Streptococcus pneumoniae, three (60 %) died within 30 days of diagnosis. CONCLUSION: Levofloxacin resistance was associated with increased mortality, along with septic shock, prior use of corticosteroids, and development of ARDS, in adult patients with IPD. Our data suggest that the emergence of levofloxacin resistance among invasive pneumococcal isolates is now becoming a challenge for clinicians managing community-acquired bacterial infections.

Characteristics of patients with Clostridium difficile infection in Taiwan.

The medical records of 84 patients with stool cultures positive for Clostridium difficile during the period August 2007 to June 2009 were retrospectively reviewed. A case of confirmed (toxigenic)C. difficile infection (CDI) was defined by the presence of symptoms (fever, diarrhoea, abdominal discomfort or distension, ileus) and the presence of toxigenic C. difficile. Patients with compatible clinical symptoms and stool cultures positive for non-toxigenic C. difficile isolates were defined as probable (non-toxigenic) CDI cases. Of these 84 patients, 50 (59.5%) were diagnosed as confirmed CDI and 34 (40.5%) as probable CDI. Thirteen (15.5%) of the 84 patients died during their hospital stay. Usage of proton pump inhibitors was a significant independent risk factor for CDI (OR 3.21, P=0.014). Of the 50 isolates associated with confirmed CDI, seven (8.3%) carried binary toxin genes (cdtAB), and six (7.1%) had a deletion in the tcdC gene. The mortality rate in confirmed CDI patients with isolates exhibiting deletion in the tcdC gene (2/6, 33.3%), those with isolates harbouring binary toxin genes (2/7, 28.6%), and those with isolates containing mutations in gyrA (2/7, 28.6%) and gyrB (1/2, 50%) was higher than the overall mortality rate (10/50, 20%) in patients with confirmed CDI.

The role of fluoroquinolones in the management of urinary tract infections in areas with high rates of fluoroquinolone-resistant uropathogens.

Fluoroquinolones have been recommended as the drugs of choice for the empirical treatment of uncomplicated and complicated urinary tract infections (UTIs) caused by trimethoprim-sulfamethoxazole-resistant uropathogens. However, because of the increased use of both oral and parenteral fluoroquinolones for other kinds of infections, increasing rates of resistance to fluoroquinolones among the most common uropathogens have challenged this recommendation, particularly in the Asia-Pacific region. The current interpretative criteria for the in vitro susceptibility of uropathogens to some fluoroquinolones, such as levofloxacin and ciprofloxacin, are set according to their therapeutic efficacy for bloodstream infections, and are not specific to UTIs. Fluoroquinolones exhibit concentration-dependent antibacterial activity, high renal excretion, and relatively early and prolonged urinary bactericidal titers. Whether or not current interpretative criteria for the in vitro susceptibility of uropathogens to fluoroquinolones predict clinical failure in treating UTIs is still controversial. The Clinical and Laboratory Standards Institute (CLSI) has established UTI-specific breakpoints for resistance to a few fluoroquinolones. However, the application of high-dose fluoroquinolone therapy for the treatment of mild to moderate UTIs caused by isolates with higher minimum inhibitory concentrations (MICs) of several fluoroquinolones needs to be re-validated based on more relevant clinical studies, prudent pharmacokinetic/pharmacodynamic (PK/PD) considerations, and thorough study of the mutant prevention concentration of fluoroquinolones in the treatment of UTI.

Culture-positive invasive aspergillosis in a medical center in Taiwan, 2000-2009.

We reviewed 776 patients who were culture positive for Aspergillus species at the hospital from 2000 to 2009. The isolates were collected for species identification by oligonucleotide hybridization and sequence analysis. A total of 96 cases of proven or probable IA were identified according to published criteria. The incidence of IA has increased significantly during the study period. Aspergillus fumigatus and A. flavus (41.7% each) were equally prevalent causative species. IA due to unusual species including A. nidulans (n=2), A. versicolor (n=2), and A. tubingensis (n=1) were also found. Among patients with IA, 55.2% had hematological disorder, 19.8% had underlying lung disorder, and 10.4% had autoimmune disease. The isolates species (P<0.001) and underlying disease (P<0.001) significantly affect the association of a positive culture with invasive disease. The overall mortality at three months was 62.5%, which remained stable throughout the study period. Multivariate analysis identified prior steroid use (P=0.007) as a significant risk factor for death, while surgery (P=0.030) and voriconazole (P=0.012) had protective effects. In conclusion, autoimmune disorders and underlying pulmonary diseases should also be considered as important predisposing factors of IA. Further emphasis on surgery and voriconazole in the management of IA might be beneficial.

Bacteremia caused by Acinetobacter junii at a medical center in Taiwan, 2000-2010.

We investigated the clinical characteristics and outcomes of 43 patients with Acinetobacter junii bacteremia at a 2,500-bed tertiary care center in northern Taiwan. These organisms were confirmed to the species level by an array assay and 16S rRNA gene sequence analysis. The antimicrobial susceptibilities of the 43 A. junii isolates to 13 agents were determined using the agar dilution method. Susceptibility testing for tigecycline was determined using the broth microdilution method. Most of the patients were hospital-acquired (n = 36, 83.7 %) or healthcare facility-related infections (n = 6, 13.9 %), and 55.8 % had impaired immunity. Central venous access devices were present in 35 (81.4 %) patients; among the total of 43 patients with A. junii bacteremia, 8 patients were diagnosed as catheter-related bloodstream infection and 19 patients were diagnosed as catheter-associated bloodstream infection. Shock requiring inotropic agents occurred in 2 patients (4.6 %). Most patients developed bacteremia in general wards (n = 36, 83.7 %). The overall in-hospital mortality rate was low (7 %), despite the low rate of removal of central venous devices, low rate of holding usage of original central venous devices, and high rate of inappropriate antimicrobial regimens. Carbapenems, fluoroquinolones, and amikacin had potent activity (>95 % susceptible rate) against A. junii isolates. Interestingly, 35 % of the A. junii isolates were resistant to colistin. Tigecycline exhibited low minimum inhibitory concentration (MIC) values (range, 0.06-2 µg/ml, MIC(90), 1 µg/ml) against the A. junii isolates.