Rapid diagnostic tests; viruses; respiratory infections; severity of illness; pandemic (H1N1) 2009; influenza; Taiwan; letter
We studied whether fluconazole or echinocandin treatment of Candida glabrata fungaemia results in superior outcomes.
A multicentre, retrospective study was performed with 224 adult patients who received ≥5 days of therapy with either fluconazole or an echinocandin as their first antifungal treatment after collection of a blood culture that grew C. glabrata. The primary outcome was day 14 complete response.
Patients in the echinocandin group were generally more ill, both at baseline and at the time of the index culture. Day 14 complete response was obtained in 58/127 (46%) and 50/97 (52%) of the fluconazole and echinocandin patients, respectively (P = 0.383). Logistic regression found intensive care unit admission to be associated with failure [OR 0.456 (0.217–0.957), P = 0.038] and echinocandin therapy to be associated with day 14 complete response [OR 2.305 (1.124–4.727), P = 0.023]. Twenty-eight day survival was similar between the fluconazole and echinocandin groups and logistic regression did not reveal antifungal therapy choice to be independently predictive of mortality. For patients treated with fluconazole, a dose : MIC ratio >12.5 (when compared with a ratio ≤12.5) was associated with a significantly higher day 14 complete response [4/20 (20%) ≤12.5 versus 50/102 (49%) >12.5, P = 0.025].
Severity of illness and choice of antifungal predict response in patients with C. glabrata fungaemia. Antifungal choice, however, does not influence mortality. In addition, new CLSI C. glabrata fluconazole susceptibility breakpoints are predictive of response when fluconazole is dosed appropriately.
pharmacodynamics; breakpoints; ICU
Colistin and tigecycline have both been shown good in vitro activity among multi-drug resistant Acinetobacter baumannii (MDRAB). A comparative study of colistin versus tigecycline for MDRAB pneumonia is lacking.
The study enrolled adults with MDRAB pneumonia admitted to intensive care units at a referral medical center during 2009–2010. Since there were no standardized minimum inhibitory concentration (MIC) interpretation criteria of tigecycline against A. baumannii, MIC of tigecycline was not routinely tested at our hospital. During the study periods, MIC of colistin was not routinely tested also. We consider both colistin and tigecycline as definite treatments of MDRAB pneumonia. Patients who received tigecycline were selected as potential controls for those who had received colistin. We performed a propensity score analysis, by considering the criteria of age, gender, underlying diseases, and disease severity, in order to match and equalize potential prognostic factors and severity in the two groups.
A total of 294 adults with MDRAB pneumonia were enrolled, including 119 who received colistin and 175 who received tigecycline. We matched 84 adults who received colistin with an equal number of controls who received tigecycline. The two well matched cohorts share similar characteristics: the propensity scores are colistin: 0.37 vs. tigecycline: 0.37, (P = .97); baseline creatinine (1.70 vs. 1.81, P = .50), and the APACHE II score (21.6 vs. 22.0, P = .99). The tigecycline group has an excess mortality of 16.7% (60.7% vs. 44%, 95% confidence interval 0.9% – 32.4%, P = .04). The excess mortality of tigecycline is significant only among those with MIC >2 μg/mL (10/12 vs. 37/84, P = .01), but not for those with MIC ≦ 2 μg/mL (4/10 vs. 37/84, P = .81).
Our data disfavors the use of tigecycline-based treatment in treating MDRAB pneumonia when tigecycline and colistin susceptibilities are unknown, since choosing tigecycline-based treatment might result in higher mortality. The excess mortality of tigecycline-based group may be related to higher MIC of tigecycline (> 2 μg/mL). Choosing tigecycline empirically for treating MDRAB pneumonia in the critical setting should be cautious.
Acinetobacter baumannii; Pneumonia; Colistin; Tigecycline; Mortality; Nephrotoxicity
The polymorphic species Candida albicans is the major cause of candidiasis in humans. The secreted aspartyl proteinases (Saps) of C. albicans, encoded by a family of 10 SAP genes, have been investigated as the virulent factors during candidiasis. However, the biological functions of most Sap proteins are still uncertain. In this study, we applied co-culture system of C. albicans and THP-1 human monocytes to explore the pathogenic roles and biological functions of Sap proteinases.
After 1 hr of co-culture of C. albicans strains and THP-1 human monocytes at 37°C, more than 60% of the THP-1-engulfed wild type and Δsap5 Candida cells were developing long hyphae. However, about 50% of THP-1-engulfed Δsap6 Candida cells were generating short hyphae, and more dead Candida cells were found in Δsap6 strain that was ingested by THP-1 cells (about 15% in Δsap6 strain vs. 2 ~ 2.5% in SC5314 and Δsap5 strains). The immunofluorescence staining demonstrated that the Sap6 is the major hyphal tip located Sap protein under THP-1 phagocytosis. The sap6-deleted strains (Δsap6, Δsap4/6, and Δsap5/6) appeared slower growth on Congo red containing solid medium at 25°C, and the growth defect was exacerbated when cultured at 37°C in Congo red or SDS containing medium. In addition, more proteins were secreted from Δsap6 strain and the β-mercaptoethanol (β-ME) extractable surface proteins from Δsap6 mutant were more abundant than that of extracted from wild type strain, which included the plasma membrane protein (Pma1p), the ER-chaperone protein (Kar2p), the protein transport-related protein (Arf1p), the cytoskeleton protein (Act1), and the mitochondrial outer membrane protein (porin 1). Moreover, the cell surface accessibility was increased in sap6-deleted strains.
From these results, we speculated that the cell surface constitution of C. albicans Δsap6 strain was defect. This may cause the more accessible of β-ME to disulfide-bridged cell surface components and may weaken the resistance of Δsap6 strain encountering phagocytosis of THP-1 cells. Sap6 protein displays a significant function involving in maintenance the cell surface integrity.
Secreted aspartyl proteinases (Saps); Candidiasis; Cell surface integrity
Drug-resistant Candida infection is a major health concern among immunocompromised patients. Antimicrobial photodynamic inactivation (PDI) was introduced as an alternative treatment for local infections. Although Candida (C.) has demonstrated susceptibility to PDI, high doses of photosensitizer (PS) and light energy are required, which may be harmful to eukaryotic human cells. This study explores the capacity of chitosan, a polycationic biopolymer, to increase the efficacy of PDI against C. albicans, as well as fluconazole-resistant clinical isolates in planktonic or biofilm states. Chitosan was shown to effectively augment the effect of PDI mediated by toluidine blue O (TBO) against C. albicans that were incubated with chitosan for 30 min following PDI. Chitosan at concentrations as low as 0.25% eradicated C. albicans; however, without PDI treatment, chitosan alone did not demonstrate significant antimicrobial activity within the 30 min of incubation. These results suggest that chitosan only augmented the fungicidal effect after the cells had been damaged by PDI. Increasing the dosage of chitosan or prolonging the incubation time allowed a reduction in the PDI condition required to completely eradicate C. albicans. These results clearly indicate that combining chitosan with PDI is a promising antimicrobial approach to treat infectious diseases.
chitosan; Candida; antimicrobial; photodynamic inactivation
Increasing the dosage of daptomycin may be advantageous in severe infection by enhancing bactericidal activity and pharmacodynamics. However, clinical data on using daptomycin at doses above 6 mg/kg in Asian population are limited.
A retrospective observational cohort study of all hospitalized adult patients treated with daptomycin (> 6 mg/kg) for at least 72 hours was performed in Taiwan.
A total of 67 patients (40 males) with a median age of 57 years received a median dose of 7.61 mg/kg (range, 6.03-11.53 mg/kg) of daptomycin for a median duration of 14 days (range, 3–53 days). Forty-one patients (61.2%) were in intensive care units (ICU). Sites of infections included complicated skin and soft tissue infections (n = 16), catheter-related bacteremia (n = 16), endocarditis (n = 11), primary bacteremia (n = 10), osteomyelitis and septic arthritis (n = 9), and miscellaneous (n = 5). The median Pitt bacteremia score among the 54 (80.6%) patients with bacteremia was 4. The most common pathogen was methicillin-resistant Staphylococcus aureus (n = 38). Fifty-nine patients (88.1%) were treated with daptomycin after glycopepetide use. Overall, 52 (77.6%) patients achieved clinical success. The all-cause mortality rate at 28 day was 35.8%. In multivariate analysis, the significant predictors of in-hospital mortality in 54 bacteremic patients were malignancies (P = 0.01) and ICU stay (P = 0.02). Adverse effects of daptomycin were generally well-tolerated, leading to discontinuation in 3 patients. Daptomycin-related creatine phosphokinase (CPK) elevations were observed in 4 patients, and all received doses > 8 mg/kg.
Treatment with high dose daptomycin as salvage therapy was generally effective and safe in Taiwan. CPK level elevations were more frequent in patients with dose > 8 mg/kg.
Daptomycin; High dose; Creatine phosphokinase; Treatment outcomes
The prevalence of vancomycin-resistant enterococci (VRE) colonization or infection in the hospital setting has increased globally. Many previous studies had analysed the risk factors for acquiring VRE, based on cross-sectional studies or prevalent cases. However, the actual incidence of and risk factors for VRE remain unclear. The present study was conducted in order to clarify the incidence of and risk factors for VRE in the intensive care unit (ICU). From 1st April 2008 to 31st March 2009, all patients admitted to a surgical ICU (SICU) were put on active surveillance for VRE. The surveillance cultures, obtained by rectal swab, were taken on admission, weekly while staying in the SICU, and on discharge from the SICU. A total of 871 patients were screened. Among them, 34 were found to carry VRE before their admission to the SICU, and 47 acquired VRE during their stay in the SICU, five of whom developed VRE infections. The incidence of newly acquired VRE during ICU stay was 21.9 per 1000 patient-days (95% confidence interval [CI], 16.4–29.1). Using multivariate analysis by logistic regression, we found that the length of ICU stay was an independent risk factor for new acquisition of VRE. In contrast, patients with prior exposure to first-generation cephalosporin were significantly less likely to acquire VRE. Strategies to reduce the duration of ICU stay and prudent usage of broad-spectrum antibiotics are the keys to controlling VRE transmission.
Diseases caused by Mycobacterium tuberculosis (TB) among adult patients with hematological malignancies have rarely been investigated.
Adult patients with hematological malignancies at National Taiwan University Hospital between 1996 and 2009 were retrospectively reviewed. Patients with positive serology for HIV were excluded. TB disease is diagnosed by positive culture(s) in the presence of compatible symptoms and signs. The demographics, laboratory and, microbiological features, were analyzed in the context of clinical outcomes.
Fifty-three of 2984 patients (1.78%) were diagnosed with TB disease. The estimated incidence was 120 per 100,000 adult patients with hematological malignancies. Patients with acute myeloid leukemia had a significantly higher incidence of TB disease than other subtypes of hematological malignancies (2.87% vs. 1.21%, p = 0.002, odds ratio, 2.40; 95% confidence interval, 1.39-4.41). Thirty-eight patients (72%) with non-disseminated pulmonary TB disease presented typically with mediastinal lymphadenopathy (53%), pleural effusion (47%) and fibrocalcific lesions (43%) on chest imaging. The 15 (28%) patients with extra-pulmonary disease had lower rates of defervescence within 72 h of empirical antimicrobial therapy (13% vs 45%, p = 0.03) and a higher 30-day in-hospital mortality (20% vs. 0%, p = 0.004) compared to those with disease confined to the lungs.
TB disease is not uncommon among patients with hematological malignancies in Taiwan. Patients who received a diagnosis of extra-pulmonary TB suffered higher mortality than those with pulmonary TB alone. Clinicians should consider TB in the differential diagnoses of prolonged fever in patients with hematological malignancies, particularly in regions of high endemicity.
Mycobacterium tuberculosis (TB); Hematological malignancy; Febrile neutropenia
Limited data describe the sustained impact of hand hygiene programs (HHPs) implemented in teaching hospitals, where the burden of healthcare-associated infections (HAIs) is high. We use a quasi-experimental, before and after, study design with prospective hospital-wide surveillance of HAIs to assess the cost effectiveness of HHPs.
Methods and Findings
A 4-year hospital-wide HHP, with particular emphasis on using an alcohol-based hand rub, was implemented in April 2004 at a 2,200-bed teaching hospital in Taiwan. Compliance was measured by direct observation and the use of hand rub products. Poisson regression analyses were employed to evaluate the densities and trends of HAIs during the preintervention (January 1999 to March 2004) and intervention (April 2004 to December 2007) periods. The economic impact was estimated based on a case-control study in Taiwan. We observed 8,420 opportunities for hand hygiene during the study period. Compliance improved from 43.3% in April 2004 to 95.6% in 2007 (p<.001), and was closely correlated with increased consumption of the alcohol-based hand rub (r = 0.9399). The disease severity score (Charlson comorbidity index) increased (p = .002) during the intervention period. Nevertheless, we observed an 8.9% decrease in HAIs and a decline in the occurrence of bloodstream, methicillin-resistant Staphylococcus aureus, extensively drug-resistant Acinetobacter baumannii, and intensive care unit infections. The intervention had no discernable impact on HAI rates in the hematology/oncology wards. The net benefit of the HHP was US$5,289,364, and the benefit-cost ratio was 23.7 with a 3% discount rate.
Implementation of a HHP reduces preventable HAIs and is cost effective.
Acinetobacter baumannii has emerged as a significant nosocomial pathogen worldwide. The increasing trend of carbapenem and fluoroquinolone resistance in A. baumannii severely limits the usage of therapeutic antimicrobial agents. Here we report the genome sequence of a multidrug-resistant A. baumannii strain, TCDC-AB0715, harboring both blaOXA-23 and blaOXA-66.
Risk factors and outcomes in hematological patients who acquire invasive fungal sinusitis (IFS) are infrequently reported in the modern medical era.
A retrospective study of hospitalized patients with hematological disease was conducted at National Taiwan University Hospital between January 1995 and December 2009.
Clinical characteristics and outcomes with their associated radiographic and microbiological findings were analyzed. Forty-six patients with IFS and 64 patients with chronic non-invasive sinusitis were enrolled as comparsion. IFS developed more commonly in patients with acute myeloid leukemia (AML) and with prolonged neutropenia (absolute neutrophil count less than 500/mm3 for more than 10 days) (p < 0.001). Aspergillus flavus was the most common pathogen isolated (44%). Serum Aspergillus galactomannan antigen was elevated in seven of eleven patients (64%) with IFS caused by aspergillosis but negative for all three patients with mucormycosis. Bony erosion and extra-sinus infiltration was found in 15 of 46 (33%) patients on imaging. Overall, 19 of 46 patients (41.3%) died within 6 weeks. Patients with disease subtype of AML (p = 0.044; Odds Ratio [OR], 5.84; 95% confidence interval [95% CI], 1.02-30.56) and refractory leukemia status (p = 0.05; OR, 4.27; 95% CI, 1.003-18.15) had worse prognosis. Multivariate analysis identified surgical debridement as an independent good prognostic factor (p = 0.047) in patients with IFS.
Patients of AML with prolonged neutropenia (> 10 days) had significantly higher risk of IFS. Early introduction of anti-fungal agent and aggressive surgical debridement potentially decrease morbidity and mortality in high risk patients with IFS.
Invasive fungal sinusitis (IFS) ; hematological disease; Aspergillus galactomanan
Vancomycin-resistant Enterococcus faecium (VRE) has become an important health care-associated pathogen because of its rapid spread, limited therapeutic options, and possible transfer of vancomycin resistance to more-virulent pathogens. In this study, we compared the ability to detect clonal relationships among VRE isolates by an automated repetitive-sequence-based PCR (Rep-PCR) system (DiversiLab system) to pulsed-field gel electrophoresis (PFGE), the reference method for molecular typing of VRE. Two sets of VRE isolates evaluated in this study were collected by active microbial surveillance at a large teaching hospital in Taiwan during 2008. The first set included 90 isolates randomly selected from the surveillance cohort. The first set consisted of 34 pulsotypes and 10 Rep-PCR types. There was good correlation between the two methods (P < 0.001). The second set included 68 VRE isolates collected from eight clusters of colonization. A dominant clone was detected in five out of eight clusters by both methods. Two clusters were characterized by Rep-PCR as being caused by a dominant clone, whereas PFGE showed polyclonal origins. One cluster was shown to be polyclonal by both methods. A single Rep-PCR clone type was detected among 12 of 14 vancomycin-intermediate enterococci, whereas PFGE detected six pulsotypes. In conclusion, the Rep-PCR method correlated well with PFGE typing but was less discriminative than PFGE in defining clonal relationships. The ease of use and more rapid turnaround time of Rep-PCR compared to PFGE offers a rapid screening method to detect outbreaks of VRE and more rapidly implement control measures. PFGE remains the preferred method to confirm clonal spread.
Multidrug-resistant (MDR) Acinetobacter spp. have emerged as a threat to public health. We investigated the various genes involved in resistance to fluoroquinolones, aminoglycosides, cephalosporins, and carbapenems in 75 clinical Acinetobacter isolates from a Taiwanese hospital. All isolates were tested for the gyrA mutations, the presence of integrons, blaAmpC, and carbapenem resistance genes. The Ser83Leu mutation in GyrA accounted for fluoroquinolone resistance. The presence of integrons containing aminoglycoside-modifying enzymes was associated with resistance to gentamicin and tobramycin but not with resistance to amikacin. The presence of an ISAba1 element upstream of blaAmpC was correlated with cephalosporin resistance. Although most Acinetobacter baumannii isolates with ISAba1-blaOXA-51-like were resistant to carbapenems, several isolates remained susceptible to carbapenems. Transformation by the introduction of ISAba1-blaOXA-23 or ISAba1-blaOXA-66 into A. baumannii ATCC 15151 (CIP 70.10), resulting in the overexpression of OXA-23 or OXA-66, respectively, suggested the role of the ISAba1 element as a strong promoter. The two transformants showed significantly increased resistance to piperacillin-tazobactam, imipenem, and meropenem. The cefepime resistance conferred by ISAba1-blaOXA-23 and the impact of ISAba1-blaOXA-66 on carbapenem resistance in A. baumannii are reported here for the first time. Continuous surveillance of antibiotic resistance genes in MDR Acinetobacter spp. and elucidation of their antibiotic resistance mechanisms are crucial for the development of therapy regimens and for the prevention of further dissemination of these antibiotic resistance genes.
Previous studies regarding the prognosis of patients infected with MRSA isolates characterized by a high minimum inhibitory concentration (MIC) for vancomycin have generally used a commercial Etest. Little research has been conducted on determining the vancomycin susceptibility of MRSA using a reference microdilution. Additionally, there is discordance between the MIC result from an Etest and the value determined using the reference microdilution method.
Using a reference microdilution method, we determined the MIC of vancomycin for isolates from 123 consecutive patients with nosocomial MRSA bacteremia. The clinical features and outcome for these patients were recorded and the MRSA isolates were genotyped.
Among the 123 non-duplicated isolates, 21.1% had a MIC = 2 mg/L, 76.4% had a MIC = 1 mg/L and 2.4% had MIC = 0.5 mg/L. Patients with MRSA bacteremia in the ICU or those who had been hospitalized for a long time were more likely to be infected with strains of high vancomycin MIC MRSA (MIC = 2 mg/L; p < 0.05). Cox regression analysis demonstrated that the high MIC group had a significantly higher 30-day mortality than the low MIC group (HR: 2.39; 95% CI: 1.20-4.79; p = 0.014). Multivariate analyses indicated that the presence of high MIC isolates, pneumonia, post-cardiothoracic surgery and a high Charlson comorbidity index were all independent predictors of a 30-day mortality. Genotyping of these high vancomycin MIC isolates demonstrated that SCCmec III, spa type037, was the predominant strain (> 80%). The rates of resistance to trimethoprim/sulfamethoxazole, gentamicin, levofloxacin, rifampin and tetracycline were also higher in the high MIC group than in the isolates belonging to low MIC group (p < 0.05).
In a high vancomycin MIC group in Taiwan, SCCmec III, spa type t037, was the predominant strain of MRSA identified. Patients with MRSA bacteremia in the ICU or who had prolonged hospitalization were more likely to be infected with S. aureus strains with high vancomycin MICs. The mortality rate was higher among patients infected with these strains compared to patients infected with low MIC strains.
This study was designed to determine the strength of the association between the isolation of nonfermentative gram-negative bacilli (NFGNB) from tap water faucet aerators and the prevalence of colonization or infection of patients in intensive care units (ICUs). Surveillance cultures were obtained during a 4-month period from 162 faucet aerators located in seven different ICUs. The prevalence of colonization or infection of ICU patients with NFGNB was determined by prospective surveillance during the same period. Fifty four (33%) of the faucet aerators contained NFGNB. Among the 66 NFGNB isolated from faucet aerators, the most frequently encountered ones were Sphingomonas paucimobili (26 isolates), Pseudomonas aeruginosa (14 isolates), Chryseobacterium meningosepticum (13 isolates), Achromobacter xylosoxidans (6 isolates), Burkholderia cepacia (4 isolates), and Stenotrophomonas maltophilia (3 isolates). Acinetobacter baumannii was not recovered. The most common NFGNB isolated from ICU patients were P. aeruginosa and A. baumannii. There was a significant correlation between the overall prevalence of NFGNB in faucet aerators and their prevalence in exposed ICU patients (Spearman r = 0.821, P = 0.02). There was also a significant correlation between the prevalence of C. meningosepticum in faucet aerators and its prevalence among ICU patients (Spearman r = 0.847, P = 0.016). The electrokaryotypes of four clinical isolates of C. meningosepticum were similar to those of faucet isolates. Measures directed at making the water supply safe may prevent infection by C. meningosepticum and other waterborne pathogens.
Molecular epidemiological definitions that are based on staphylococcal cassette chromosome mec (SCCmec) typing and phylogenetic analysis of methicillin-resistant Staphylococcus aureus (MRSA) isolates are considered a reliable way to distinguish between healthcare-associated MRSA (HA-MRSA) and community-associated MRSA (CA-MRSA). However, there is little information regarding the clinical features and outcomes of bacteremia patients with MRSA carrying different SCCmec types.
From January 1 through December 31, 2006, we recorded the demographic data and outcomes of 159 consecutive adult MRSA bacteremia patients from whom isolates for SCCmec analysis were collected. All participants were patients at a tertiary care center in Taiwan.
The following SCCmec types were identified in MRSA isolates: 30 SCCmec II (18.9%), 87 SCCmec III (54.7%), 22 SCCmec IV (13.8%), and 20 SCCmec V (12.6%). The time from admission to the first MRSA-positive blood culture for patients infected with isolates with the SCCmec III element (mean/median, 50.7/26 days) was significantly longer than for patients infected with isolates carrying SCCmec IV or V (mean/median, 6.7/3 days for SCCmec IV; 11.1/10.5 days for SCCmec V) (P<0.05). In univariate analysis, community onset, soft tissue infection, and deep-seated infection were predictors for SCCmec IV/V. In multivariate analysis, length of stay before index culture, diabetes mellitus, and being bedridden were independent risk factors associated with SCCmec II/III.
These findings are in agreement with previous studies of the genetic characteristics of CA-MRSA. MRSA bacteremia with SCCmec II/III isolates occurred more among patients with serious comorbidities and prolonged hospitalization. Community onset, skin and soft tissue infection, and deep-seated infection best predicted SCCmec IV/V MRSA bacteremia.
Acinetobacter spp. have emerged as important nosocomial and multidrug-resistant pathogens in the last decade. A. calcoaceticus, A. baumannii, Acinetobacter genospecies 3, and Acinetobacter genospecies 13TU are genetically closely related and are referred to as the A. calcoaceticus-A. baumannii complex (ACB complex). Distinct Acinetobacter spp. may be associated with differences in antimicrobial susceptibility, so it is important to identify Acinetobacter spp. at the species level. We developed a microsphere-based array that combines an allele-specific primer extension assay and microsphere hybridization for the identification of Acinetobacter spp. This assay can discriminate the 13 different Acinetobacter spp. in less than 8.5 h, and it has high specificity without causing cross-reactivity with 14 other common nosocomial bacterial species. The sensitivity of this assay was 100 A. baumannii cells per ml of blood, and it could discriminate multiple species in various mixture ratios. The developed assay could differentiate clinical Acinetobacter spp. isolates with a 90% identification rate. The antimicrobial susceptibility test showed that A. baumannii isolates were resistant to most antimicrobial agents other than imipenem, while the genospecies 3 and 13TU isolates were more susceptible to most antimicrobial agents, especially ciprofloxacin and ampicillin-sulbactam. These results supported the idea that this assay possibly could be applied to clinical samples and provide accurate species identification, which might be helpful for clinicians when they are treating infections caused by Acinetobacter spp.
Galactomannan (GM) is a heteropolysaccharide in the cell walls of most Aspergillus and Penicillium species. Cross-reactivity of Cryptococcus neoformans galactoxylomannan in an Aspergillus GM test has also been reported. In this study, we used a Platelia Aspergillus enzyme immunoassay kit (Bio-Rad) to test serum samples obtained from 48 human immunodeficiency virus (HIV)-infected patients (15 with penicilliosis [7 with fungemia alone, 4 with cavitary lung lesions alone, 3 with both fungemia and cavitary lung lesions, and 1 with disseminated disease], 22 with cryptococcosis [11 with fungemia alone, 5 with cavitary lung lesions, 3 with both, and 3 with meningitis alone], and 11 without any invasive fungal infection [control]) for GM levels. None of the patients had aspergillosis or concurrent use of piperacillin-tazobactam or amoxicillin-clavulanate. The median time between diagnosis of fungal infection and collection of serum samples was 0 days for penicilliosis and 1.5 days for cryptococcosis. Of patients with penicilliosis, cryptococcosis, and controls, 73.3%, 13.6%, and 9%, respectively, had GM optical density (OD) indices of >0.5 (P = 0.0001). GM OD indices were higher for penicilliosis (median OD index, 4.419; range, 0.158 to >20) than for cryptococcosis (median, 0.247; range, 0.112 to 3.849) cases (P < 0.001). Patients with fungemic penicilliosis had higher OD indices (median, 10.628; range, 0.401 to >20) than patients with nonfungemic penicilliosis (median, 0.378; range, 0.158 to 4.419) and patients with cryptococcemia (median, 0.231; range, 0.112 to 1.168) (P < 0.001). Of the 15 patients with cavitary lung lesions, those with penicilliosis had higher antigen levels (median OD index, 1.641; range, 0.247 to >20) than those with cryptococcosis (median, 0.227; range, 0.112 to 3.849) (P = 0.011). This study showed that the GM OD index was significantly elevated for HIV patients with penicilliosis. The use of the GM antigen assay may facilitate earlier diagnosis of Penicillium marneffei infection for HIV-infected patients in areas of endemicity.
In this study, 80 Candida glabrata isolates from intensive care unit and human immunodeficiency virus (HIV)-infected patients were typed by multilocus sequence typing (MLST), pulsed-field gel electrophoresis (PFGE), and mating type class determination. Among the 25 patients with multiple isolates, 19 patients (76%) contained multiple isolates exhibiting identical or highly related PFGE and MLST genotypes, which may indicate the maintenance or microvariation of one C. glabrata strain in each patient. However, isolates from six patients (24%) displayed different sequence types, PFGE genotypes, or mating type classes, which may indicate colonization with more than one clone over time or strain replacement. High correlations among PFGE genotypes, sequence types, and mating types were found (P < 0.01). MLST exhibited less discriminatory power than PFGE with BssHII. The genotypes, sequence types, and mating type classes were independent of anatomic sources, drug susceptibility, and HIV infection status.
Brain abscesses are occasionally associated with a dental source of infection. An unusual case of frontal lobe abscess in a nonimmunocompromised child infected with multidrug-resistant Capnocytophaga ochracea is described and confirms the pathogenic potential of this organism to cause human disease in the central nervous system.
To determine the predominant staphylococcal cassette chromosome (SCC) mec element in methicillin-resistant Staphylococcus aureus, we typed 190 isolates from a hospital in Taiwan. We found a shift from type IV to type III SCCmec element during 1992–2003, perhaps caused by selective pressure from indiscriminate use of antimicrobial drugs.
Methicillin-resistant Staphylococcus aureus; multilocus sequence typing; SCCmec; dispatch
Multilocus sequence typing (MLST) was used to characterize the genetic profiles of 51 Candida albicans isolates collected from 12 hospitals in Taiwan. Among the 51 isolates, 16 were epidemiologically unrelated, 28 were isolates from 11 critically ill, human immunodeficiency virus (HIV)-negative patients, and 7 were long-term serial isolates from 3 HIV-positive patients. Internal regions of seven housekeeping genes were sequenced. A total of 83 polymorphic nucleotide sites were identified. Ten to 20 different genotypes were observed at the different loci, resulting, when combined, in 45 unique genotype combinations or diploid sequence types (DSTs). Thirty (36.1%) of the 83 individual changes were synonymous and 53 (63.9%) were nonsynonymous. Due to the diploid nature of C. albicans, MLST was more discriminatory than the pulsed-field gel electrophoresis-BssHII-restricted fragment method in discriminating epidemiologically related strains. MLST is able to trace the microevolution over time of C. albicans isolates in the same patient. All but one of the DSTs of our Taiwanese strain collections were novel to the internet C. albicans DST database (http://test1.mlst.net/). The DSTs of C. albicans in Taiwan were analyzed together with those of the reference strains and of the strains from the United Kingdom and United States by unweighted-pair group method using average linkages and minimum spanning tree. Our result showed that the DNA type of each isolate was patient specific and associated with ABC type and decade of isolation but not associated with mating type, anatomical source of isolation, hospital origin, or fluconazole resistance patterns.
The clinical picture of severe acute respiratory syndrome (SARS) is characterized by pulmonary inflammation and respiratory failure, resembling that of acute respiratory distress syndrome. However, the events that lead to the recruitment of leukocytes are poorly understood. To study the cellular response in the acute phase of SARS coronavirus (SARS-CoV)-host cell interaction, we investigated the induction of chemokines, adhesion molecules, and DC-SIGN (dendritic cell-specific ICAM-3-grabbing nonintegrin) by SARS-CoV. Immunohistochemistry revealed neutrophil, macrophage, and CD8 T-cell infiltration in the lung autopsy of a SARS patient who died during the acute phase of illness. Additionally, pneumocytes and macrophages in the patient's lung expressed P-selectin and DC-SIGN. In in vitro study, we showed that the A549 and THP-1 cell lines were susceptible to SARS-CoV. A549 cells produced CCL2/monocyte chemoattractant protein 1 (MCP-1) and CXCL8/interleukin-8 (IL-8) after interaction with SARS-CoV and expressed P-selectin and VCAM-1. Moreover, SARS-CoV induced THP-1 cells to express CCL2/MCP-1, CXCL8/IL-8, CCL3/MIP-1α, CXCL10/IP-10, CCL4/MIP-1β, and CCL5/RANTES, which attracted neutrophils, monocytes, and activated T cells in a chemotaxis assay. We also demonstrated that DC-SIGN was inducible in THP-1 as well as A549 cells after SARS-CoV infection. Our in vitro experiments modeling infection in humans together with the study of a lung biopsy of a patient who died during the early phase of infection demonstrated that SARS-CoV, through a dynamic interaction with lung epithelial cells and monocytic cells, creates an environment conducive for immune cell migration and accumulation that eventually leads to lung injury.
The serum antibodies to severe acute respiratory syndrome (SARS) coronavirus of 18 SARS patients were checked at 1 month and every 3 months after disease onset. All of them except one, who missed blood sampling at 1 month, tested positive for the immunoglobulin G (IgG) antibody at 1 month. Fifteen out of 17 tested positive for the IgM antibody at 1 month. The serum IgM antibody of most patients became undetectable within 6 months after the onset of SARS. The IgG antibody of all 17 patients, whose serum was checked 1 year after disease onset, remained positive.
We examined severe acute respiratory syndrome-associated coronavirus (SARS-CoV) RNA in plasma of 32 patients (probable SARS cases) by a quantitative real-time reverse transcription-PCR assay and reported that the highest detection rate, 75%, was found between day 5 and day 7 of illness, followed by rates of 64, 50, and 38% found between day 8 and day 11, day 2 and day 4, and day 12 and day 16, respectively. Analysis of sequential SARS-CoV load in plasma from six cases revealed different patterns of viremia, with the peak between day 4 and day 8. Our findings of the high detection rate of SARS-CoV RNA in plasma before day 11, together with the relative convenience of collecting and handling plasma, suggest that plasma can be used for early diagnosis of SARS.