-
Infection & Chemotherapy Dec 2017HACEK is a rare cause of prosthetic valve endocarditis (PVE). We describe 42-year-old male patient who presented with Aggregatibacter aphrophilus PVE and cerebral...
HACEK is a rare cause of prosthetic valve endocarditis (PVE). We describe 42-year-old male patient who presented with Aggregatibacter aphrophilus PVE and cerebral infarct. A. aphrophilus was isolated from his blood cultures as the sole pathogen, which was confirmed by subsequent 16S rRNA sequencing. He was treated with valve replacement surgery and an 8 week course of pathogen-directed antibiotic therapy and followed for 20 months without recurrence.
PubMed: 28608662
DOI: 10.3947/ic.2017.49.4.282 -
Journal of Microbiology, Immunology,... Aug 2017
Topics: Aggregatibacter aphrophilus; DNA, Bacterial; Endocarditis, Bacterial; Humans; Male; Middle Aged; Mitral Valve; Mitral Valve Annuloplasty; Pasteurellaceae Infections; Polymerase Chain Reaction; RNA, Ribosomal, 16S; Sequence Analysis, DNA; Taiwan; Treatment Outcome
PubMed: 28716361
DOI: 10.1016/j.jmii.2016.10.002 -
Annals of Pediatric Cardiology Jul 2011Kingella kingae, a HACEK (Haemophilus parainfluenzae, Aggregatibacter actinomycetemcomitans, Aggregatibacter aphrophilus, Cardiobacterium hominis, Eikenella corrodens,...
Kingella kingae, a HACEK (Haemophilus parainfluenzae, Aggregatibacter actinomycetemcomitans, Aggregatibacter aphrophilus, Cardiobacterium hominis, Eikenella corrodens, Kingella kingae) organism, is a common resident of the upper airway in children; it has been associated with endocarditis in children with pre-existing heart conditions. This case report describes K. kingae endocarditis leading to valvular damage in a previously healthy 18-month-old child. Our patient developed a K. kingae bacteremia that was later complicated by meningitis, septic embolic stroke, and endocarditis of the mitral valve, leading to perforation of the posterolateral leaflet. The patient was initially treated conservatively with cefotaxime but, subsequently, required a mitral valve repair with a pericardial patch and annuloplasty. This report draws attention to the need for clinicians to be aware of the potentially serious complications of K. kingae infection in young children. If K. kingae infection is suspected then therapy should be initiated promptly with a β-lactam, followed by early echocardiographic assessment. This case also highlights the lack of specific guidelines available for K. kingae endocarditis.
PubMed: 21976892
DOI: 10.4103/0974-2069.84664 -
Journal of Clinical Microbiology Jun 1997Restriction enzyme analysis of PCR-amplified 16S rRNA genes was used to distinguish among clinical isolates of Actinobacillus actinomycetemcomitans, Haemophilus...
Rapid identification of Actinobacillus actinomycetemcomitans, Haemophilus aphrophilus, and Haemophilus paraphrophilus by restriction enzyme analysis of PCR-amplified 16S rRNA genes.
Restriction enzyme analysis of PCR-amplified 16S rRNA genes was used to distinguish among clinical isolates of Actinobacillus actinomycetemcomitans, Haemophilus aphrophilus, and Haemophilus paraphrophilus which were originally identified by conventional phenotypic methods. This PCR-based method is a reliable and rapid alternative to conventional methods for identification of these bacterial species.
Topics: Adult; Aggregatibacter actinomycetemcomitans; Bacterial Typing Techniques; DNA, Bacterial; Deoxyribonucleases, Type II Site-Specific; Haemophilus; Humans; Polymerase Chain Reaction; RNA, Bacterial; RNA, Ribosomal, 16S; Sensitivity and Specificity
PubMed: 9163503
DOI: 10.1128/jcm.35.6.1630-1632.1997 -
Infection and Immunity Dec 1999Actinobacillus actinomycetemcomitans SUNY 465, the invasion prototype strain, enters epithelial cells by an actin-dependent mechanism, escapes from the host cell...
Actinobacillus actinomycetemcomitans SUNY 465, the invasion prototype strain, enters epithelial cells by an actin-dependent mechanism, escapes from the host cell vacuole, and spreads intracellularly and to adjacent epithelial cells via intercellular protrusions. Internalized organisms also egress from host cells into the assay medium via protrusions that are associated with just a single epithelial cell. Here we demonstrate that agents which inhibit microtubule polymerization (e.g., colchicine) and those which stabilize polymerized microtubules (e.g., taxol) both increase markedly the number of intracellular A. actinomycetemcomitans organisms. Furthermore, both colchicine and taxol prevented the egression of A. actinomycetemcomitans from host cells into the assay medium. Immunofluorescence microscopy revealed that protrusions that mediate the bacterial spread contain microtubules. A. actinomycetemcomitans SUNY 465 and 652, strains that are both invasive and egressive, interacted specifically with the plus ends (growing ends) of the filaments of microtubule asters in a KB cell extract. By contrast, neither A. actinomycetemcomitans 523, a strain that is invasive but not egressive, nor Haemophilus aphrophilus, a noninvasive oral bacterium with characteristics similar to those of A. actinomycetemcomitans, bound to microtubules. Together these data suggest that microtubules function in the spread and movement of A. actinomycetemcomitans and provide the first evidence that host cell dispersion of an invasive bacterium may involve the usurption of host cell microtubules.
Topics: Aggregatibacter actinomycetemcomitans; Colchicine; Colony Count, Microbial; Culture Media; Humans; KB Cells; Microscopy, Fluorescence; Microtubules; Movement; Paclitaxel
PubMed: 10569770
DOI: 10.1128/IAI.67.12.6518-6525.1999 -
BMC Microbiology Jul 2013Accurate identification of fastidious Gram-negative rods (GNR) by conventional phenotypic characteristics is a challenge for diagnostic microbiology. The aim of this...
BACKGROUND
Accurate identification of fastidious Gram-negative rods (GNR) by conventional phenotypic characteristics is a challenge for diagnostic microbiology. The aim of this study was to evaluate the use of molecular methods, e.g., 16S rRNA gene sequence analysis for identification of fastidious GNR in the clinical microbiology laboratory.
RESULTS
A total of 158 clinical isolates covering 20 genera and 50 species isolated from 1993 to 2010 were analyzed by comparing biochemical and 16S rRNA gene sequence analysis based identification. 16S rRNA gene homology analysis identified 148/158 (94%) of the isolates to species level, 9/158 (5%) to genus and 1/158 (1%) to family level. Compared to 16S rRNA gene sequencing as reference method, phenotypic identification correctly identified 64/158 (40%) isolates to species level, mainly Aggregatibacter aphrophilus, Cardiobacterium hominis, Eikenella corrodens, Pasteurella multocida, and 21/158 (13%) isolates correctly to genus level, notably Capnocytophaga sp.; 73/158 (47%) of the isolates were not identified or misidentified.
CONCLUSIONS
We herein propose an efficient strategy for accurate identification of fastidious GNR in the clinical microbiology laboratory by integrating both conventional phenotypic methods and 16S rRNA gene sequence analysis. We conclude that 16S rRNA gene sequencing is an effective means for identification of fastidious GNR, which are not readily identified by conventional phenotypic methods.
Topics: Bacteriological Techniques; Gram-Negative Bacteria; Humans; Molecular Diagnostic Techniques; Molecular Sequence Data; RNA, Ribosomal, 16S; Sensitivity and Specificity; Sequence Analysis, DNA
PubMed: 23855986
DOI: 10.1186/1471-2180-13-162 -
Oral Microbiology and Immunology Dec 1998The epithelial cell invasiveness of Actinobacillus actinomycetemcomitans strains of different restriction fragment-length polymorphism (RFLP) groups associated with... (Comparative Study)
Comparative Study
Epithelial cell invasion by Actinobacillus actinomycetemcomitans strains from restriction fragment-length polymorphism groups associated with juvenile periodontitis or carrier status.
The epithelial cell invasiveness of Actinobacillus actinomycetemcomitans strains of different restriction fragment-length polymorphism (RFLP) groups associated with disease conversion and asymptomatic carrier status in localized juvenile periodontitis was examined. Twenty clinical isolates were studied for their ability to invade KB monolayers, using the quantitative gentamicin killing assay. Five isolates were found to be invasive, five were not invasive; and the other 10 did not invade better than an invasion negative control Haemophilus aphrophilus strain ATCC 19415. Using probe-specific DNA fingerprinting. 11 strains were assigned to RFLP group II (disease-associated); 4 to RFLP type XIII (carrier status associated); and the other to groups III, IV, V and VII. Eight isolates, all RFLP group II, were leukotoxin producers as determined by PCR amplification of the lkt promoter region. No correlation was found between invasiveness and RFLP group. Leukotoxin production was more associated with noninvasive than invasive strains.
Topics: Aggregatibacter actinomycetemcomitans; Aggressive Periodontitis; Bacterial Toxins; Carrier State; Epithelial Cells; Exotoxins; Humans; KB Cells; Polymorphism, Restriction Fragment Length; Virulence
PubMed: 9872109
DOI: 10.1111/j.1399-302x.1998.tb00689.x