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2.
Mycoses ; 66(8): 711-722, 2023 Aug.
Article in English | MEDLINE | ID: mdl-37186489

ABSTRACT

BACKGROUND: Epidemiological knowledge is important to guide antifungal therapy. OBJECTIVE: This multicentre study aimed to investigate the species distribution and antifungal susceptibility of Aspergillus isolates in Taiwan. METHOD: Four hundred and ninety-two clinical Aspergillus isolates, collected during 2016-2020, were identified by calmodulin sequencing and tested for antifungal susceptibility using CLSI M38-A3. The Cyp51A sequences of azole-resistant Aspergillus fumigatus and Aspergillus flavus isolates were analysed. RESULTS: This collection comprised 30 species from eight Aspergillus sections-Flavi (33.5%), Nigri (26.0%), Fumigati (24.2%), Terrei (10.0%), Nidulantes (5.1%), Circumdati (0.8%), Restricti (0.2%) and Aspergillus (0.2%). Sections Fumigati, Flavi and Terrei were primarily represented by A. fumigatus (99.2%), A. flavus (95.8%) and A. terreus (100%), respectively. Section Nigri comprised nine species, mostly A. welwitschiae (60.2%), A. niger (12.5%), A. brunneoviolaceus (10.9%) and A. tubingensis (10.2%). A. fumigatus (39.6%) and A. flavus (26.4%) predominated among 53 isolates from lower respiratory samples, whereas section Nigri species (46.2%) and A. terreus (29.2%) predominated among 65 isolates from ear samples. Reduced susceptibility to amphotericin B (minimal inhibitory concentration (MIC) > 1 µg/mL) was noted in A. flavus (7.0%), A. terreus (6.1%), A. nidulans and section Circumdati (A. flocculosus, A. subramanianii and A. westerdijkiae) isolates. Acquired azole resistance was observed in seven A. fumigatus (5.9%), all of which carried TR34 /L98H or TR34 /L98H/S297T/F495I mutation, and three A. flavus (1.9%), one of which carried G441S mutation. Reduced susceptibility to itraconazole (MIC >1 µg/mL) was noted in 55.5% of section Nigri isolates, mainly in A. welwitschiae, A. niger and A. tubingensis, whereas A. brunneoviolaceus, A. aculeatinus and A. japonicus were hypersusceptible to azoles. Anidulafungin was active against all isolates except for one isolate. CONCLUSIONS: This study depicted the molecular epidemiology and species-specific characteristics of Aspergillus in Taiwan, which aids in appropriate antifungal therapy and underlines the need of speciation and susceptibility testing of disease-causing Aspergillus.


Subject(s)
Antifungal Agents , Aspergillus , Humans , Antifungal Agents/pharmacology , Taiwan/epidemiology , Itraconazole/pharmacology , Azoles/pharmacology , Aspergillus fumigatus , Microbial Sensitivity Tests , Drug Resistance, Fungal/genetics , Fungal Proteins/genetics
3.
Biomed J ; 46(4): 100555, 2023 08.
Article in English | MEDLINE | ID: mdl-35964939

ABSTRACT

This study characterizes the phylogenetic relatedness of non-SARS human coronaviruses (HCoVs) in southern Taiwan by sequencing the nucleocapsid (N), spike (S), and RNA-dependent RNA polymerase (RdRp) genes directly from ten HCoV PCR-positive respiratory samples collected during 2012-2013. In the N, S1, and RdRp phylogeny, HCoV-OC43 in one and three samples was clustered with genotypes F and G, respectively, and HCoV-OC43 in sample YC101/TWN/2013 represented a recombination event between genotypes F and G. Amino acid substitutions in the S1 protein of HCoV-OC43 were also identified. In the N phylogeny, HCoV-HKU1 in one and two samples clustered with genotypes A and B, respectively, and HCoV-229E in two samples was clustered with genogroup 6. The genotypes and genogroup detected here were in line with the prevalent phylogenetic lineages reported outside of Taiwan during the contemporary period. In summary, three species of non-SARS HCoVs with different genotypes cocirculated in the community, with genetic evolution observed in HCoV-OC43.


Subject(s)
Coronavirus Infections , Coronavirus OC43, Human , Humans , Phylogeny , Coronavirus Infections/epidemiology , Taiwan , RNA-Dependent RNA Polymerase/genetics
4.
J Fungi (Basel) ; 8(1)2022 Jan 04.
Article in English | MEDLINE | ID: mdl-35049989

ABSTRACT

This study delineated the characteristics of 24 (11.2%) culture-positive, influenza-associated pulmonary aspergillosis (IAPA) patients out of 215 patients with severe influenza during 2016-2019 in a medical center in southern Taiwan. Twenty (83.3%) patients did not have EORTC/MSG-defined host factors. The mean time from influenza diagnosis to Aspergillus growth was 4.4 days, and 20 (83.3%) developed IAPA within seven days after influenza diagnosis. All patients were treated in intensive care units and all but one (95.8%) received mechanical ventilation. Aspergillus tracheobronchitis was evident in 6 (31.6%) of 19 patients undergoing bronchoscopy. Positive galactomannan testing of either serum or bronchoalveolar lavage was noted in all patients. On computed tomography imaging, IAPA was characterized by peribronchial infiltrates, multiple nodules, and cavities superimposed on ground-glass opacities. Pure Aspergillus growth without bacterial co-isolation in culture was found in 17 (70.8%) patients. A. fumigatus (15, 62.5%), A. flavus (6, 25.0%), and A. terreus (4, 16.7%) were the major causative species. Three patients had mixed Aspergillus infections due to two species, and two had mixed azole-susceptible and azole-resistant A. fumigatus infection. All patients received voriconazole with an all-cause mortality of 41.6%. Of 14 survivors, the mean duration of antifungal use was 40.5 days. In conclusion, IAPA is an early and rapidly deteriorating complication following influenza that necessitates clinical vigilance and prompt diagnostic workup.

5.
Emerg Infect Dis ; 26(4): 804-806, 2020 04.
Article in English | MEDLINE | ID: mdl-32186508

ABSTRACT

In a multicenter study, we determined a prevalence rate of 4% for azole-resistant Aspergillus fumigatus in Taiwan. Resistance emerged mainly from the environment (TR34/L98H, TR34/L98H/S297T/F495I, and TR46/Y121F/T289A mutations) but occasionally during azole treatment. A high mortality rate observed for azole-resistant aspergillosis necessitates diagnostic stewardship in healthcare and antifungal stewardship in the environment.


Subject(s)
Aspergillus fumigatus , Azoles , Antifungal Agents/pharmacology , Antifungal Agents/therapeutic use , Aspergillus fumigatus/genetics , Azoles/pharmacology , Drug Resistance, Fungal , Fungal Proteins/genetics , Microbial Sensitivity Tests , Taiwan/epidemiology
6.
Mycoses ; 62(12): 1174-1181, 2019 Dec.
Article in English | MEDLINE | ID: mdl-31549427

ABSTRACT

Poor clinical outcomes for invasive aspergillosis are associated with antifungal resistance. Performing antifungal susceptibility tests on clinically relevant Aspergillus isolates from patients and environmental regions with known azole resistance is recommended. The aim of the study was to assess the presence of azole resistance in clinical Aspergillus spp. isolates and those from hospital environments and farmlands within a 40 km radius of the hospital. Clinical Aspergillus spp. isolates were cultured, as well as environmental Aspergillus spp. isolates obtained from air samples. Samples were subcultured in azole-containing agar plates. Isolates with a positive screening test were subjected to YeastOne methods to determine their minimum inhibitory concentrations of antifungals. Resistance mechanisms were investigated in the azole-resistant Aspergillus spp. isolates. No azole-resistant clinical or environmental A flavus, A oryaze, A niger or A terreus isolates were found in the present study. All A fumigatus clinical isolates were azole-susceptible. Seven A fumigatus environmental isolates were associated with cyp51A mutations, including two that harboured TR34 /L98H mutations with S297T/F495I substitutions, two with TR34 /L98H mutations and three with TR46 /Y121F/T289A mutations. One of these isolates was collected from farmland, one was from A ward and five were from B ward. The proportion of azole-resistant A fumigatus was 10.2% (6/59) and 3.2% (1/31) in the hospital environments and the farmlands near the hospital, respectively. The results showed that azole-resistant A fumigatus existed within hospital environments. This emphasises the importance of periodic surveillance in hospital environments and monitoring for the emergence of azole-resistant A fumigatus clinical isolates.


Subject(s)
Antifungal Agents/pharmacology , Aspergillosis/epidemiology , Aspergillus/drug effects , Azoles/pharmacology , Drug Resistance, Multiple, Fungal , Epidemiological Monitoring , Aspergillosis/microbiology , Aspergillus/genetics , Aspergillus/isolation & purification , Cytochrome P-450 Enzyme System/genetics , Farms , Fungal Proteins/genetics , Genotype , Hospitals , Humans , Microbial Sensitivity Tests , Mutation , Taiwan/epidemiology
7.
J Clin Microbiol ; 56(10)2018 10.
Article in English | MEDLINE | ID: mdl-30093391

ABSTRACT

This study compared the YeastOne and reference CLSI M38-A2 broth microdilution methods for antifungal susceptibility testing of Aspergillus species. The MICs of antifungal agents were determined for 100 Aspergillus isolates, including 54 Aspergillus fumigatus (24 TR34/L98H isolates), 23 A. flavus, 13 A. terreus, and 10 A. niger isolates. The overall agreement (within 2 2-fold dilutions) between the two methods was 100%, 95%, 92%, and 90% for voriconazole, posaconazole, itraconazole, and amphotericin B, respectively. The voriconazole geometric mean (GM) MICs were nearly identical for all isolates using both methods, whereas the itraconazole and posaconazole GM MICs obtained using the YeastOne method were approximately 1 dilution lower than those obtained using the reference method. In contrast, the amphotericin B GM MIC obtained using the YeastOne method was 3.3-fold higher than that observed using the reference method. For the 24 A. fumigatus TR34/L98H isolates assayed, the categorical agreement (classified according to the CLSI epidemiological cutoff values) was 100%, 87.5%, and 83.3% for itraconazole, voriconazole, and posaconazole, respectively. For four A. niger isolates, the itraconazole MICs were >8 µg/ml using the M38-A2 method due to trailing growth, whereas the corresponding itraconazole MICs obtained using the YeastOne method were all ≤0.25 µg/ml without trailing growth. These data suggest that the YeastOne method can be used as an alternative for azole susceptibility testing of Aspergillus species and for detecting the A. fumigatus TR34/L98H isolates but that this method fails to detect A. niger isolates exhibiting trailing growth with itraconazole. Additionally, for isolates with azole MICs that approach or that are at susceptibility breakpoints or with high amphotericin B MICs detected using the YeastOne method, further MIC confirmation using the reference CLSI method is needed.


Subject(s)
Antifungal Agents/pharmacology , Aspergillus/drug effects , Microbial Sensitivity Tests/methods , Microbial Sensitivity Tests/standards , Amphotericin B/pharmacology , Aspergillosis/microbiology , Aspergillus/classification , Aspergillus/isolation & purification , Drug Tolerance , Humans , Itraconazole/pharmacology , Reference Standards , Species Specificity , Triazoles/pharmacology , Voriconazole/pharmacology
8.
Environ Microbiol ; 20(1): 270-280, 2018 01.
Article in English | MEDLINE | ID: mdl-29124846

ABSTRACT

Emerging azole resistance in Aspergillus fumigatus poses a serious threat to human health. This nationwide surveillance study investigated the prevalence and molecular characteristics of azole-resistant A. fumigatus environmental isolates in Taiwan, an island country with increasing use of azole fungicides. Of the 2760 air and soil samples screened from 2014 to 2016, 451 A. fumigatus isolates were recovered from 266 samples and 34 isolates from 29 samples displayed resistance to medical azoles (itraconazole, voriconazole or posaconazole). The resistance prevalence was 10.9% and 7.5% in A. fumigatus-positive samples and isolates respectively. Most (29, 85.3%) azole-resistant isolates harboured TR34 /L98H mutations, which were widely distributed, clustered genetically with clinical isolates, and had growth rates that were similar to those of the wild-type isolates. Microsatellite genotyping revealed both the global spread of the TR34 /L98H isolates and the occurrence of TR34 /L98H/S297T/F495I isolates belonging to local microsatellite genotypes. AfuMDR3 and atrF, two efflux transporter genes, were constitutively upregulated in two individual resistant isolates without cyp51A mutations, highlighting their potential roles in azole resistance. These results emphasize the need for periodic environmental surveillance at the molecular level in regions in which azole fungicides are applied, and agricultural fungicide management strategies that generate less selective pressure should be investigated.


Subject(s)
Antifungal Agents/therapeutic use , Aspergillosis/drug therapy , Aspergillosis/epidemiology , Aspergillus fumigatus/drug effects , Aspergillus fumigatus/genetics , Azoles/therapeutic use , Drug Resistance, Fungal/genetics , Air Microbiology , Aspergillosis/microbiology , Aspergillus fumigatus/isolation & purification , Cytochrome P-450 Enzyme System/genetics , Fungal Proteins/genetics , Genotype , Humans , Itraconazole/therapeutic use , Microbial Sensitivity Tests , Microsatellite Repeats/genetics , Mutation/genetics , Prevalence , Soil Microbiology , Taiwan/epidemiology , Triazoles/therapeutic use , Voriconazole/therapeutic use
9.
Medicine (Baltimore) ; 94(38): e1545, 2015 Sep.
Article in English | MEDLINE | ID: mdl-26402811

ABSTRACT

Viral etiologies of respiratory tract infections (RTIs) have been less studied in adult than in pediatric populations. Furthermore, the ability of PCR/electrospray ionization mass spectrometry (PCR/ESI-MS) to detect enteroviruses and rhinoviruses in respiratory samples has not been well evaluated. We sought to use PCR/ESI-MS to comprehensively investigate the viral epidemiology of adult RTIs, including testing for rhinoviruses and enteroviruses. Nasopharyngeal or throat swabs from 267 adults with acute RTIs (212 upper RTIs and 55 lower RTIs) who visited a local clinic or the outpatient or emergency departments of a medical center in Taiwan between October 2012 and June 2013 were tested for respiratory viruses by both virus isolation and PCR/ESI-MS. Throat swabs from 15 patients with bacterial infections and 27 individuals without active infections were included as control samples. Respiratory viruses were found in 23.6%, 47.2%, and 47.9% of the 267 cases by virus isolation, PCR/ESI-MS, and both methods, respectively. When both methods were used, the influenza A virus (24.3%) and rhinoviruses (9.4%) were the most frequently identified viruses, whereas human coronaviruses, human metapneumovirus (hMPV), enteroviruses, adenoviruses, respiratory syncytial virus, and parainfluenza viruses were identified in small proportions of cases (<5% of cases for each type of virus). Coinfection was observed in 4.1% of cases. In the control group, only 1 (2.4%) sample tested positive for a respiratory virus by PCR/ESI-MS. Patients who were undergoing steroid treatment, had an active malignancy, or suffered from chronic obstructive pulmonary disease (COPD) were at risk for rhinovirus, hMPV, or parainfluenza infections, respectively. Overall, immunocompromised patients, patients with COPD, and patients receiving dialysis were at risk for noninfluenza respiratory virus infection. Rhinoviruses (12.7%), influenza A virus (10.9%), and parainfluenza viruses (7.3%) were the most common viruses involved in the 55 cases of lower RTIs. The factors of parainfluenza infection, old age, and immunosuppression were independently associated with lower RTIs. In conclusion, PCR/ESI-MS improved the diagnostic yield for viral RTIs. Non-influenza respiratory virus infections were associated with patients with comorbidities and with lower RTIs. Additional studies that delineate the clinical need for including non-influenza respiratory viruses in the diagnostic work-up in these populations are warranted.


Subject(s)
Enterovirus Infections , Enterovirus/isolation & purification , Picornaviridae Infections , Respiratory Tract Infections , Rhinovirus/isolation & purification , Adult , Aged , Coinfection/epidemiology , Emergency Service, Hospital/statistics & numerical data , Enterovirus Infections/diagnosis , Enterovirus Infections/epidemiology , Female , Humans , Male , Middle Aged , Outpatients/statistics & numerical data , Pharynx/virology , Picornaviridae Infections/diagnosis , Picornaviridae Infections/epidemiology , Polymerase Chain Reaction/methods , Respiratory Tract Infections/diagnosis , Respiratory Tract Infections/epidemiology , Respiratory Tract Infections/virology , Spectrometry, Mass, Electrospray Ionization/methods , Taiwan/epidemiology
10.
Mycoses ; 58(9): 544-9, 2015 Sep.
Article in English | MEDLINE | ID: mdl-26214171

ABSTRACT

Cumulative evidence described the emergence and geographical expansion of azole-resistant A. fumigatus associated with azole treatment failure. To investigate the status of azole resistance in A. fumigatus in Taiwan, we studied 38 A. fumigatus clinical isolates cultivated from 31 patients at two teaching hospitals from 2011 to 2014. Three isolates obtained from respiratory samples of two azole-naïve patients with pulmonary aspergillosis were found to display multi-azole resistance and cross resistance to agricultural azole fungicides, and all carried TR34/L98H mutations in cyp51A gene. The prevalence rates of azole resistance were 7.9% and 6.5% based on isolates and patients respectively. A phylogenetic analysis suggested genetic diversity of the TR34/L98H isolates in Taiwan, including a unique genotype distinct from strains outside Taiwan. The result underlines the emergence of such isolates in Taiwan as well, emphasising the importance of further surveillance for azole-resistant A. fumigatus and implementation of strategies that prevent fungicide-driven resistance selection.


Subject(s)
Antifungal Agents/pharmacology , Aspergillus fumigatus/drug effects , Aspergillus fumigatus/genetics , Cytochrome P-450 Enzyme System/genetics , Drug Resistance, Multiple, Fungal/genetics , Fungal Proteins/genetics , Mutation , Aspergillus fumigatus/isolation & purification , Azoles , Genetic Variation , Genotype , Humans , Microbial Sensitivity Tests , Molecular Sequence Data , Mutation, Missense , Phylogeny , Pulmonary Aspergillosis/epidemiology , Pulmonary Aspergillosis/microbiology , Retrospective Studies , Taiwan/epidemiology , Time Factors
11.
Genome Announc ; 3(2)2015 Apr 23.
Article in English | MEDLINE | ID: mdl-25908123

ABSTRACT

Most of the published complete genome sequences of Helicobacter pylori strains are limited to clinical isolates associated with gastritis, peptic ulcers, or gastric cancer. The genome sequences of three H. pylori strains isolated from patients with gastric mucosa-associated lymphoid tissue (MALT) lymphoma are presented here to facilitate studies of H. pylori-associated MALT lymphomagenesis.

12.
PLoS One ; 10(2): e0117821, 2015.
Article in English | MEDLINE | ID: mdl-25679227

ABSTRACT

BACKGROUND: Advances in Aeromonas taxonomy have led to the reclassification of aeromonads. Hereon, we aimed to re-evaluate the characteristics of Aeromonas bacteremia, including those of a novel species, Aeromonas dhakensis. METHODOLOGY/PRINCIPAL FINDINGS: A retrospective study of monomicrobial Aeromonas bacteremia at a medical center in southern Taiwan from 2004-2011 was conducted. Species identification was based on rpoB sequencing. Of bacteremia of 153 eligible patients, A. veronii (50 isolates, 32.7%), A. dhakensis (48, 31.4%), A. caviae (43, 28.1%), and A. hydrophila (10, 6.5%) were the principal causative species. A. dhakensis and A. veronii bacteremia were mainly community-acquired and presented as primary bacteremia, spontaneous bacterial peritonitis, or skin and soft-tissue infection, whereas A. caviae was associated with hospital-onset bacteremia. The distribution of the AmpC ß-lactamase and metallo-ß-lactamase genes was species-specific: bla(AQU-1), bla(MOX), or bla(CepH) was present in A. dhakensis, A. caviae, or A. hydrophila, respectively, and bla(CphA) was present in A. veronii, A. dhakensis, and A. hydrophila. The cefotaxime resistance rates of the A. caviae, A. dhakensis, and A. hydrophila isolates were higher than that of A. veronii (39.5%%, 25.0%, and 30% vs. 2%, respectively). A. dhakensis bacteremia was linked to the highest 14-day sepsis-related mortality rate, followed by A. hydrophila, A. veronii, and A. caviae bacteremia (25.5%, 22.2%, 14.0%, and 4.7%, respectively; P = 0.048). Multivariate analysis revealed that A. dhakensis bacteremia, active malignancies, and a Pitt bacteremia score ≥ 4 was an independent mortality risk factor. CONCLUSIONS/SIGNIFICANCE: Characteristics of Aeromonas bacteremia vary between species. A. dhakensis prevalence and its associated poor outcomes suggest it an important human pathogen.


Subject(s)
Aeromonas/classification , Bacteremia/microbiology , Gram-Negative Bacterial Infections/microbiology , Adult , Aeromonas/drug effects , Aeromonas/genetics , Aged , Anti-Bacterial Agents/pharmacology , Anti-Bacterial Agents/therapeutic use , Bacterial Proteins/genetics , Comorbidity , Female , Gram-Negative Bacterial Infections/diagnosis , Gram-Negative Bacterial Infections/drug therapy , Gram-Negative Bacterial Infections/mortality , Humans , Male , Microbial Sensitivity Tests , Middle Aged , Retrospective Studies , Treatment Outcome , beta-Lactamases/genetics
13.
Genome Announc ; 2(3)2014 Jun 12.
Article in English | MEDLINE | ID: mdl-24926060

ABSTRACT

Aeromonas taiwanensis was first described in 2010 on the basis of one clinical wound isolate (strain LMG 24683(T) = A2-50(T) = CECT 7403(T)) from Taiwan. We present here the genome sequence of A. taiwanensis LMG 24683(T), which carries several genes encoding virulence determinants and Ambler class C and D ß-lactamases.

14.
J Clin Microbiol ; 52(4): 1217-9, 2014 Apr.
Article in English | MEDLINE | ID: mdl-24430451

ABSTRACT

PCR coupled with electrospray ionization mass spectrometry (PCR/ESI-MS) was compared with culture for pathogen detection in peritoneal dialysis (PD)-related peritonitis. Of 21 samples of PD effluent, PCR/ESI-MS identified microorganisms in 18 (86%) samples, including Mycobacterium tuberculosis in 1 culture-negative sample. Of 15 double-positive samples, PCR/ESI-MS and culture reached levels of agreement of 100% (15/15) and 87.5% (7/8) at the genus and species levels, respectively. PCR/ESI-MS can be used for rapid pathogen detection in PD-related peritonitis.


Subject(s)
Bacteria/isolation & purification , Bacterial Infections/diagnosis , Candida/isolation & purification , Candidiasis/diagnosis , Dialysis Solutions , Microbiological Techniques/methods , Peritonitis/diagnosis , Adult , Aged , Bacterial Infections/microbiology , Candidiasis/microbiology , Child , Female , Humans , Male , Middle Aged , Peritoneal Dialysis/adverse effects , Peritonitis/microbiology , Polymerase Chain Reaction/methods , Spectrometry, Mass, Electrospray Ionization/methods , Young Adult
15.
Diagn Microbiol Infect Dis ; 78(2): 141-3, 2014 Feb.
Article in English | MEDLINE | ID: mdl-24268535

ABSTRACT

Polymerase chain reaction coupled with electrospray ionization mass spectrometry (PCR/ESI-MS) was successfully used to identify a variety of fungi, including mixed fungal species, from 10 of 12 clinical specimens (10 culture-negative) of biopsy tissues or body fluids from patients with fungal infections. The application of PCR/ESI-MS for identifying fungal pathogens is discussed.


Subject(s)
Fungi/classification , Fungi/genetics , Multilocus Sequence Typing , Polymerase Chain Reaction , Spectrometry, Mass, Electrospray Ionization , Adolescent , Adult , Aged , Child , Child, Preschool , Humans , Middle Aged , Mycoses/diagnosis , Mycoses/microbiology , Sensitivity and Specificity , Young Adult
16.
Int J Antimicrob Agents ; 42(5): 456-61, 2013 Nov.
Article in English | MEDLINE | ID: mdl-24055254

ABSTRACT

Aeromonas dhakensis, a recently described Aeromonas sp. formerly called Aeromonas aquariorum, is associated with human infections. In this study, a chromosomal gene, blaAQU-1, was identified in A. dhakensis AAK1 that constitutes a 1143-bp open reading frame and is 87% identical to the gene encoding CepH in Aeromonas hydrophila. An Escherichia coli TOP10 cell transformant harbouring blaAQU-1 was resistant to cefotaxime but not to cefepime. mRNA expression of blaAQU-1 in the cefotaxime-resistant mutant strain AAK1m was 70-fold higher than in the wild strain AAK1. In all 16 A. dhakensis isolates (the major species of 51 consecutive Aeromonas blood isolates collected from June 1999 to June 2001) as well as in A. aquariorum MDC47(T) and A. hydrophila subsp. dhakensis LMG 19562(T), but not in the reference strains or clinical isolates of other A. hydrophila subspecies, Aeromonas caviae, Aeromonas veronii or Aeromonas enteropelogenes, blaAQU-1-related genes were detected by PCR. Overall, 13 (81%) of the 16 A. dhakensis blood isolates exhibited either cefotaxime resistance or the in vitro emergence of derepressed cefotaxime-resistant mutants. In vivo selection of an A. dhakensis resistant mutant was noted in a burn patient undergoing cefotaxime monotherapy. These observations suggest that AQU-1 is a chromosomal cephalosporinase in A. dhakensis. Cefotaxime monotherapy for severe A. dhakensis infections should be used cautiously.


Subject(s)
Aeromonas/drug effects , Aeromonas/enzymology , Cephalosporinase/metabolism , Gram-Negative Bacterial Infections/microbiology , Aeromonas/genetics , Aeromonas/isolation & purification , Cephalosporinase/genetics , Cluster Analysis , DNA, Bacterial/chemistry , DNA, Bacterial/genetics , Humans , Molecular Sequence Data , Open Reading Frames , Phylogeny , Polymerase Chain Reaction , Sequence Analysis, DNA , Sequence Homology
17.
J Bacteriol ; 194(15): 4114-5, 2012 Aug.
Article in English | MEDLINE | ID: mdl-22815437

ABSTRACT

Aeromonas aquariorum, a recently described species, is associated with a variety of human diseases. We present here the first genome sequence of A. aquariorum strain AAk1, which was isolated as the sole pathogen from the blood of a patient with septicemia and necrotizing fasciitis.


Subject(s)
Aeromonas/genetics , DNA, Bacterial/chemistry , DNA, Bacterial/genetics , Genome, Bacterial , Sequence Analysis, DNA , Aeromonas/isolation & purification , Blood/microbiology , Fasciitis, Necrotizing/complications , Fasciitis, Necrotizing/microbiology , Gram-Negative Bacterial Infections/microbiology , Humans , Molecular Sequence Data , Sepsis/microbiology
18.
J Med Virol ; 84(4): 679-85, 2012 Apr.
Article in English | MEDLINE | ID: mdl-22337309

ABSTRACT

The carbohydrate binding specificities are different among avian and human influenza A viruses and may affect the tissue tropism and transmission of these viruses. The glycan binding biology for influenza B, however, has not been systematically characterized. Glycan binding specificities of influenza B viral isolates were analyzed and correlated to hemagglutinin (HA) genotypes and clinical manifestations. A newly developed solution glycan array was applied to characterize the receptor binding specificities of influenza B virus clinical isolates from 2001 to 2007 in Taiwan. Thirty oligosaccharides which include α-2,3 and α-2,6 linkage glycans were subjected to analysis. The glycan binding patterns of 53 influenza B isolates could be categorized into three groups and were well correlated to their HA genotypes. The Yamagata-like strains predominantly bound to α-2,6-linkage glycan (24:29, 83%) while Victoria-like strains preferentially bound to both α-2,3- and α-2,6-linkage glycans (13:24, 54%). A third group of viruses bound to sulfated glycans and these all belonged to Victoria-like strains. Based on the HA sequences, Asn-163, Glu-198, Ala-202, and Lys-203 were conserved among Victoria-like strains which may influence their carbohydrate recognition. The viruses bound to dual type glycans were more likely to be associated with the development of bronchopneumonia and gastrointestinal illness than those bound only to α-2,6 sialyl glycans (P < 0.05). Glycan binding analyses provide additional information to monitor the antigenic shift, tissue tropism, and transmission capability of influenza B viruses, and will contribute to virus surveillance and vaccine strain selection.


Subject(s)
Hemagglutinin Glycoproteins, Influenza Virus/genetics , Hemagglutinin Glycoproteins, Influenza Virus/metabolism , Influenza B virus/physiology , Influenza, Human/virology , Polysaccharides/metabolism , Virus Attachment , Genotype , Humans , Influenza B virus/genetics , Influenza B virus/isolation & purification , Influenza, Human/pathology , Taiwan
19.
Clin Vaccine Immunol ; 17(12): 1958-62, 2010 Dec.
Article in English | MEDLINE | ID: mdl-20876823

ABSTRACT

A novel pandemic influenza H1N1 (pH1N1) virus spread rapidly across the world in 2009. Due to the important role of antibody-mediated immunity in protection against influenza infection, we used an enzyme-linked immunosorbent assay-based microneutralization test to investigate cross-reactive neutralizing antibodies against the 2009 pH1N1 virus in 229 stored sera from donors born between 1917 and 2008 in Taiwan. The peak of cumulative geometric mean titers occurred in donors more than 90 years old and declined sharply with decreasing age. Sixteen of 27 subjects (59%) more than 80 years old had cross-reactive antibody titers of 160 or more against the 2009 pH1N1 virus, whereas none of the donors from age 9 to 49 had an antibody titer of 160 or more. Interestingly, 2 of 51 children (4%) from 6 months to 9 years old had an antibody titer of 40. We further tested the antibody responses in 9 of the 51 pediatric sera to three endemic seasonal influenza viruses isolated in 2006 and 2008 in Taiwan, and the results showed that only the 2 sera from children with antibody responses to the 2009 pH1N1 virus had high titers of neutralizing antibody against recent seasonal influenza virus strains. Our study shows the presence of some level of cross-reactive antibody in Taiwanese persons 50 years old or older, and the elderly subjects who may already have been exposed to the 1918 virus had high titers of neutralizing antibody to the 2009 pH1N1 virus. Our data also indicate that natural infection with the Taiwan 2006 and 2008 seasonal H1N1 viruses may induce a cross-reactive antibody response to the 2009 pH1N1 virus.


Subject(s)
Antibodies, Viral/blood , Influenza A Virus, H1N1 Subtype/immunology , Influenza, Human/epidemiology , Influenza, Human/immunology , Adult , Aged , Aged, 80 and over , Antibodies, Neutralizing/blood , Child , Child, Preschool , Cross Reactions , Enzyme-Linked Immunosorbent Assay , Female , Humans , Infant , Male , Middle Aged , Neutralization Tests , Seroepidemiologic Studies , Taiwan/epidemiology , Young Adult
20.
Arch Virol ; 153(12): 2207-13, 2008.
Article in English | MEDLINE | ID: mdl-19002556

ABSTRACT

An outbreak of human metapneumovirus (hMPV) among children in southern Taiwan in 2004 prompted the investigation of the molecular epidemiology of hMPV from September 2003 to August 2005. Respiratory specimens that were culture negative for a panel of respiratory viruses were examined for the presence of hMPV by RT-PCR. The results indicated that 59 out of 546 (10.8%) children were hMPV-positive. The majority of these hMPV-positive children were less than 2 years old (59.4%), females (61%), and inpatients (67.8%). Infections occurred throughout the year, but peaked during the spring and/or summer months. Sequence analysis of the fusion gene from the isolates revealed two phylogenetic groups with five possible lineages (A1, A2a/A2b, B1, and B2). Among these co-circulating strains, A2 strains were most frequently observed and demonstrated the greatest divergence. Deduced amino acid sequence analysis identified several variant amino acids specific to the A2 lineage. Lineage-specific amino acid substitutions were noted at aa233, aa286, aa312, aa348, and aa296. This study indicated that genetically divergent strains of hMPV which caused respiratory disease and hospitalization were circulating among children in Taiwan.


Subject(s)
Metapneumovirus/genetics , Paramyxoviridae Infections/epidemiology , Amino Acid Substitution/genetics , Child, Preschool , Female , Genetic Variation , Humans , Infant , Male , Metapneumovirus/classification , Metapneumovirus/isolation & purification , Paramyxoviridae Infections/virology , Phylogeny , Taiwan/epidemiology
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