The rapid emergence (from 0% before 1998 to 6.5% in 2000) of pandrug-resistant Acinetobacter baumannii (PDRAB) was noted in a university hospital in Taiwan. To understand the epidemiology of these ...isolates, we studied 203 PDRAB isolates, taken from January 1999 to April 2000: 199 from 73 hospitalized patients treated at different clinical settings in the hospital and 4 from environmental sites in an intensive-care unit. Pulsed-field gel electrophoresis analysis and random amplified polymorphic DNA (RAPD) generated by arbitrarily primed polymerase chain reaction of these 203 isolates showed 10 closely related genotypes (10 clones). One (clone 5), belonging to pulsotype E and RAPD pattern 5, predominated (64 isolates, mostly from patients in intensive care). Increasing use of carbapenems and ciprofloxacin (selective pressure) as well as clonal dissemination might have contributed to the wide spread of PDRAB in this hospital.
To investigate the clinical, epidemiologic, and microbiological characteristics of community-acquired pneumonia (CAP) due to Acinetobacter baumannii.
Retrospective chart and radiographic reviews of ...all patients who were admitted to National Taiwan University Hospital from January 1993 to August 1999, fulfilled the criteria for CAP, and had an isolate of A baumannii from blood or pleural fluid at hospital admission.
Thirteen patients (9 men and 4 women; age range, 37 to 85 years) met the criteria. Conditions associated with the infection included male gender, old age, alcoholism, malignancy, cerebrovascular disease, diabetes mellitus, renal disease, and liver cirrhosis. Eleven patients (85%) acquired the infection during the warmer months of April to October. Twelve patients (92%) had a fulminant course presenting with septic shock and respiratory failure, and 11 patients (85%) needed ventilator support and were treated in an ICU. Six patients (46%) had leukopenia. Lobar consolidations were found in 12 patients (92%), and pleural effusions were present in 4 patients (31%). All patients had positive blood culture results, two patients (15%) had positive pleural effusion culture findings, and nine patients (69%) positive sputum culture results. All the isolates were susceptible to imipenem, and most were susceptible to aminoglycosides, ceftazidime, ciprofloxacin, and extended-spectrum penicillins. Eight patients (62%) died. Four of the five survivors were initially treated with combination of a third-generation cephalosporin and an aminoglycoside.
A baumannii should be considered as a possible etiologic agent in community-acquired lobar pneumonia when (1) patients with a fulminant course present during the warmer and more humid months of the year, and (2) patients are younger alcoholics. A good sputum smear, defined as a Gram stain smear of an adequate sputum specimen that comes from the lower respiratory tract and contains > 25 leukocytes per high-power (100×) field on microscopic examination, can help early diagnosis and treatment. A combination of a third-generation cephalosporin and an aminoglycoside may be appropriate empirical therapy.
Candidemia is a significant cause of morbidity and mortality in hospitalized patients, particularly in Asia. Anidulafungin has been reported to be an effective treatment for candidemia in Western ...populations, but little is known about its efficacy in Asian patients, where the clinical presentation and epidemiology may be different.
An open-label study of anidulafungin for the treatment of candidemia was recently conducted in several Asian countries. Treatment was initiated with intravenous anidulafungin, given for at least 5 days, with the option to complete treatment with oral voriconazole. The primary endpoint was global (clinical and microbiological) response, and the primary analysis was the proportion of patients in the modified intent-to-treat population with successful global response at the end of therapy. Secondary analyses included proportion with successful global response in clinically relevant patient subgroups. The safety and tolerability profile of anidulafungin and voriconazole in this population was also investigated.
Forty-three patients were studied, including 42 in the modified intent-to-treat population. Eighteen patients were > 65 years, the largest age subgroup, and 21 had central venous catheters. The most common Candida species causing infection were C. tropicalis (n = 18) and C. albicans (n = 10). In the primary analysis, 73.8% had a successful global response at end of therapy. Success rates in subgroups were: 72.2% for C. tropicalis and 71.4% for C. albicans infection, 58.8% for patients > 65 years, and 81.0% for patients with central venous catheters. Safety and tolerability were comparable with the known profiles for anidulafungin (and voriconazole).
Although the epidemiology of Candida infections was different in this open-label study, the efficacy of anidulafungin in Asian patients with documented candidemia was consistent with previous studies in Western populations. No new safety concerns were identified.
http://www.clinicaltrials.gov identifier NCT00537329.
Abstract Background/Purpose This study was conducted to compare the mutation rates of different rpoB sites and rifampin minimum inhibitory concentration (MIC) changes prior to and after rifampin ...therapy for biofilm-embedded methicillin-resistant Staphylococcus aureus (MRSA) isolates. Methods The screening of rifampin-resistant MRSA isolates, from the biofilm at Day 5 with or without exposure to the susceptible breakpoint concentration of rifampin recommended by the Clinical and Laboratory Standards Institute (1 mg/L), was conducted using agar plates containing rifampin. A partial fragment of RNA polymerase B subunit gene ( rpoB ), including clusters I and II, was amplified and sequenced. The rifampin MIC values and mutation frequencies at different sites of rpoB were measured and evaluated in rifampicin-resistant isolates. Results Rifampin-resistant mutants could be selected from all of 39 randomly selected rifampin-susceptible MRSA isolates in the biofilm model. The spontaneous mutation frequency ranged from 1.00 × 10−4 to 3.85 × 10−7 . Mutation at codon 481 was most commonly found at 35 (89.7%) of 39 MRSA isolates. Without rifampin induction, the MIC ranged between 0.125 mg/L and1024 mg/L and mutation sites included cluster I 464, 466, 468, 471, 474, 477, 481, 484, 486 and cluster II 519, 527, 529 with the percentage of 471 (35.9%), 477 (33.3%), 481 (53.8%), and 484 (35.9%). Conversely, with the induction of rifampin, the MIC value ranged ∼256–1024 mg/L. The mutation sites that were more concentrated included 468 (17.9%), 477 (30.8%), 481 (89.7%), 484 (17.9%), and 486 (33.3%). Conclusion We documented high rifampin resistance induction activity when MRSA was engaged in biofilm with rifampin exposure. Monotherapy seems to be inadequate for MRSA in biofilm. There is an urgent need for developing effective combination therapies with less rifampin resistance-inducing activities for treating MRSA in biofilms.
Abstract During the period 2001–2010, a total of 154 episodes of candidaemia were noted in 111 of 2574 patients with haematological malignancies at the National Taiwan University Hospital (Taipei, ...Taiwan). Patients with acute lymphoblastic leukaemia had a significantly higher rate of candidaemia than patients with other haematological malignancies (odds ratio = 2.69; P < 0.001). Candida tropicalis was the most common Candida species ( n = 51; 46%), followed by Candida albicans ( n = 35; 32%), Candida parapsilosis ( n = 13; 12%), Candida glabrata ( n = 8; 7%) and Candida krusei ( n = 4; 4%). Persistent candidaemia was initially identified in 21 patients (18.9%) and was frequently associated with central venous catheter-related infection (52% vs. 24%; P = 0.017). Multivariate analysis revealed that shock ( P < 0.001), allogeneic transplantation ( P = 0.033) and elderly age (≥60 years) ( P = 0.041) were independent prognostic factors of 30-day overall survival in patients with haematological malignancy and candidaemia. Minimum inhibitory concentrations (MICs) of a total of 103 non-duplicate blood isolates of Candida spp., including 82 isolates from 82 patients without persistent candidaemia and 21 isolates causing first episodes among 21 patients with persistent candidaemia, to nine antifungal agents were determined using the broth microdilution method. Among the 103 Candida isolates, 53 (51.5%), 94 (91.3%) and 102 (99.0%) were susceptible to itraconazole, fluconazole and voriconazole, respectively. All Candida isolates were susceptible to caspofungin, and 2 (15%) of the 13 C. parapsilosis isolates were not susceptible to micafungin or anidulafungin. The MIC90 (MIC for 90% of the organisms) of posaconazole was 0.03 mg/L for C. albicans , 0.5 mg/L for C. tropicalis , 0.12 mg/L for C. parapsilosis and 2 mg/L for C. glabrata.
Abstract Human infections due to Roseomonas species are uncommon and the vast majority of reported infections are opportunistic and easy to treat. We retrospectively reviewed the computerized ...database of the Bacteriology Laboratory at the National Taiwan University Hospital to identify patients with infections caused by Roseomonas species during the period January 2000 to December 2010. Isolates of Roseomonas species were confirmed by 16S rRNA gene sequencing analysis. During the study period, 20 patients had cultures positive for Roseomonas species. R. mucosa was the most prevalent isolate ( n = 18), followed by 1 each of R. gilardii and Roseomonas genomospecies 5. True infection caused by Roseomonas species was confirmed in 17 (85%) patients. Most ( n = 12, 71%) of these infections were health care–associated infection. The majority of the patients ( n = 12, 71%) had underlying diseases. Malignancy was the most common underlying disease, and catheter-related bloodstream infection was the most common type of infection. The antimicrobial susceptibility patterns varied among the different Roseomonas species. In conclusion, Roseomonas species can cause infection in children and adults regardless of immune status. Because different Roseomonas species may have different clinical features and susceptibility profiles, molecular studies are necessary to identify Roseomonas isolates to the species level.
The severe acute respiratory syndrome-associated coronavirus (SARS-CoV) is thought to be transmitted primarily through dispersal of droplets, but little is known about the load of SARS-CoV in oral ...droplets. We examined oral specimens, including throat wash and saliva, and found large amounts of SARS-CoV RNA in both throat wash (9.58 x 10(2) to 5.93 x 10(6) copies/mL) and saliva (7.08 x 10(3) to 6.38 x 10(8) copies/mL) from all specimens of 17 consecutive probable SARS case-patients, supporting the possibility of transmission through oral droplets. Immunofluorescence study showed replication of SARS-CoV in the cells derived from throat wash, demonstrating the possibility of developing a convenient antigen detection assay. This finding, with the high detection rate a median of 4 days after disease onset and before the development of lung lesions in four patients, suggests that throat wash and saliva should be included in sample collection guidelines for SARS diagnosis.
The systemic surveillance of imipenem-resistant Acinetobacter baumannii (IRAB) from multicenters in Taiwan revealed the emergence of isolates with bla.sub.OXA-72. This study described their genetic ...makeup, mechanism of spread, and contribution to carbapenem resistance. Two hundred and ninety-one non-repetitive isolates of A. baumannii were collected from 10 teaching hospitals from different geographical regions in Taiwan from June 2007 to September 2007. Minimal inhibitory concentrations (MICs) were determined by agar dilution. Clonality was determined by pulsed-field gel electrophoresis. Plasmid was extracted and digested by restriction enzymes, and subsequently analyzed by electrophoresis and Southern blot for bla.sub.OXA-72. The flanking regions of bla.sub.OXA-72 were determined by inverse PCR. The contribution of bla.sub.OXA-72 to imipenem MIC was determined by transforming plasmids carrying bla.sub.OXA-72 into imipenem-susceptible A. baumannii. Among 142 IRAB in Taiwan, 27 harbored bla.sub.OXA-72; 22 originated from Southern Taiwan, 5 from Central Taiwan, and none from Northern Taiwan. There were two major clones. The bla.sub.OXA-72 was identified in the plasmids of all isolates. Two genetic structures flanking plasmid-borne bla.sub.OXA-72 were identified and shared identical sequences in certain regions; the one described in previous literature was present in only one isolate, and the new one was present in the remaining isolates. Introduction of bla.sub.OXA-72 resulted in an increase of imipenem MIC in the transformants. The overexpression of bla.sub.OXA-72 mRNA in response to imipenem further supported the contribution of bla.sub.OXA-72. In conclusion, isolates with new plasmid-borne bla.sub.OXA-72 were found to be disseminated successfully in Southern Taiwan. The spread of the resistance gene depended on clonal spread and dissemination of a new plasmid. Bla.sub.OXA-72 in these isolates directly led to their imipenem-resistance.
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