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BMC Research Notes Dec 2014Aggregatibacter bacteria are a rare cause of endocarditis in adults. They are part of a group of organisms known as HACEK--Haemophilus, Aggregatibacter, Cardiobacter,...
BACKGROUND
Aggregatibacter bacteria are a rare cause of endocarditis in adults. They are part of a group of organisms known as HACEK--Haemophilus, Aggregatibacter, Cardiobacter, Eikenella, and Kingella. Among these organisms, several Haemophilus species have been reclassified under the genus Aggregatibacter. Very few cases of Aggregatibacter endocarditis in patients with pacemaker devices have been reported.
CASE PRESENTATION
We present here what we believe to be the first case of Aggregatibacter aphrophilus pacemaker endocarditis. A 62-year-old African American male with a medical history significant for dual-chamber pacemaker placement in 1996 for complete heart block with subsequent lead manipulation in 2007, presented to his primary care doctor with fever, chills, night sweats, fatigue, and ten-pound weight loss over a four-month period. Physical examination revealed a new murmur and jugular venous distension which prompted initiation of antibiotics for suspicion of endocarditis. Both sets of initial blood cultures were positive for A. aphrophilus. Transesophageal echocardiogram revealed vegetations on the tricuspid valve and the right ventricular pacemaker lead (Figure 1). This case highlights the importance of identifying rare causes of endocarditis and recognizing that treatment may not differ from the standard treatment for typical presentations. The patient received intravenous ceftriaxone for his endocarditis for a total of six weeks. Upon device removal, temporary jugular venous pacing wires were placed. After two weeks of antibiotic treatment and no clinical deterioration, a new permanent pacemaker was placed and the patient was discharged home.
CONCLUSIONS
This is the first case of A. aphrophilus endocarditis in a patient with a permanent pacemaker. Our patient had no obvious risk factors other than poor dentition and a history of repeated pacemaker lead manipulation. This suggests that valvulopathies secondary to repeated lead manipulation can be clinically significant factors in morbidity and mortality in this patient population.
Topics: Aggregatibacter aphrophilus; Anti-Bacterial Agents; Ceftriaxone; Echocardiography, Transesophageal; Endocarditis, Bacterial; Humans; Male; Middle Aged; Pacemaker, Artificial
PubMed: 25486984
DOI: 10.1186/1756-0500-7-885 -
Journal of Bacteriology Jul 2009We report the finished and annotated genome sequence of Aggregatibacter aphrophilus strain NJ8700, a strain isolated from the oral flora of a healthy individual, and...
We report the finished and annotated genome sequence of Aggregatibacter aphrophilus strain NJ8700, a strain isolated from the oral flora of a healthy individual, and discuss characteristics that may affect its dual roles in human health and disease. This strain has a rough appearance, and its genome contains genes encoding a type VI secretion system and several factors that may participate in host colonization.
Topics: DNA, Bacterial; Genome, Bacterial; Humans; Molecular Sequence Data; Pasteurellaceae; Sequence Analysis, DNA
PubMed: 19447908
DOI: 10.1128/JB.00447-09 -
Nature Communications Sep 2023Soluble HMW1C-like N-glycosyltransferases (NGTs) catalyze the glycosylation of Asn residues in proteins, a process fundamental for bacterial autoaggregation, adhesion...
Soluble HMW1C-like N-glycosyltransferases (NGTs) catalyze the glycosylation of Asn residues in proteins, a process fundamental for bacterial autoaggregation, adhesion and pathogenicity. However, our understanding of their molecular mechanisms is hindered by the lack of structures of enzymatic complexes. Here, we report structures of binary and ternary NGT complexes of Aggregatibacter aphrophilus NGT (AaNGT), revealing an essential dyad of basic/acidic residues located in the N-terminal all α-domain (AAD) that intimately recognizes the Thr residue within the conserved motif Asn-X-Ser/Thr. Poor substrates and inhibitors such as UDP-galactose and UDP-glucose mimetics adopt non-productive conformations, decreasing or impeding catalysis. QM/MM simulations rationalize these results, showing that AaNGT follows a S2 reaction mechanism in which the acceptor asparagine uses its imidic form for catalysis and the UDP-glucose phosphate group acts as a general base. These findings provide key insights into the mechanism of NGTs and will facilitate the design of structure-based inhibitors to treat diseases caused by non-typeable H. influenzae or other Gram-negative bacteria.
Topics: Glycosylation; Bacterial Proteins; Asparagine; Haemophilus influenzae; Glucose; Uridine Diphosphate
PubMed: 37723184
DOI: 10.1038/s41467-023-41238-1 -
Infection and Drug Resistance 2024The HACEK group comprises spp., , , , and , are Gram-negative bacteria that are slow-growing and fastidious. These organisms are common causes of...
BACKGROUND
The HACEK group comprises spp., , , , and , are Gram-negative bacteria that are slow-growing and fastidious. These organisms are common causes of culture-negative endocarditis. However, brain abscesses caused by and have been rarely reported. The case we describe, which was promptly identified and successfully treated, will be meaningful for the diagnosis and treatment of such infectious diseases.
CASE PRESENTATION
Herein, we report a case of brain abscess in a young man who was infected with and . The patient was admitted to the hospital with sudden onset of vomiting, coma, and fever. Magnetic resonance imaging (MRI) of the brain and cerebrospinal fluid cell counts suggested cerebral abscess, he underwent drainage of the abscess and empirical antimicrobial therapy of meropenem (2 g every 8 hours) and linezolid (0.6 g every 12 hours) for more than 10 days without significant improvement. Metagenomic next-generation sequencing (mNGS) of drainage fluid and matrix-assisted laser desorption ionization-time-of-flight mass spectrometry (MALDI-TOF MS) detection for isolated bacteria from samples suggested the presence of and . After 7 weeks of ceftriaxone (2 g every 12 hours) and meropenem (2 g every 8 hours) intravenously, the patient was discharged with a normal temperature and brain MRI showed improvement of the lesion.
CONCLUSION
Similar cases reported in previous studies were always associated with bacterial blood dissemination after dental surgery or myocarditis; however, the patient in our case had no any associated risk factors. As far as we know, this is the only case of central nervous system infection caused by and that has utilized combined mNGS and MALDI-TOF MS in the diagnosis.
PubMed: 38628241
DOI: 10.2147/IDR.S458020 -
Blood Transfusion = Trasfusione Del... Sep 2021The aim of the study was to determine if periodontitis, which often causes transient bacteraemia, associates with viable bacteria in standard blood donations.
BACKGROUND
The aim of the study was to determine if periodontitis, which often causes transient bacteraemia, associates with viable bacteria in standard blood donations.
MATERIALS AND METHODS
This was a cross-sectional study of 60 self-reported medically healthy blood donors aged over 50 years. According to standard procedures, whole blood was separated by fractionation into plasma, buffy-coat, and red blood cell (RBC)-fractions. The buffy-coat was screened for bacterial contamination using BacT/ALERT. Samples from plasma and RBC-fractions were incubated anaerobically and aerobically at 37°C for 7 days on trypticase soy blood agar (TSA). For identification, colony polymerase chain reaction was performed using primers targeting 16S rDNA.
RESULTS
From 62% of the donors with periodontitis, bacterial growth was observed on at least 1 out of 4 plates inoculated with plasma or RBCs, whereas only 13% of plates inoculated with plasma or RBCs from periodontally healthy controls yielded bacterial growth (relative risk 6.4, 95% CI: 2.1; 19.5; p=0.0011). None of the donors tested positive for bacterial contamination using BacT/ALERT. Cutibacterium acnes was found in 31% of the donations from donors with periodontitis and in 10% of the donations from periodontally healthy donors. In addition, Staphylococcus species, Bacillus mycoides, Aggregatibacter aphrophilus, and Corynebacterium kroppenstedtii were detected.
DISCUSSION
Periodontitis increased the risk of bacterial contamination of blood products. Contaminating bacteria are often associated with the RBC-fraction. As the BacT/ALERT test is generally performed on platelet products, routine screening fails to detect many occurrences of viable bacteria in the RBC-fraction.
Topics: Aged; Bacteria; Blood Donors; Blood Platelets; Cross-Sectional Studies; Erythrocytes; Humans; Periodontitis
PubMed: 33539285
DOI: 10.2450/2021.0336-20 -
Acta Medica Academica 2015The aim of this report was to describe the occurrence of a bacterial brain abscess in a healthy individual, without any predisposing condition.
OBJECTIVE
The aim of this report was to describe the occurrence of a bacterial brain abscess in a healthy individual, without any predisposing condition.
CASE REPORT
A thirteen-year old boy was admitted to the Department of Neurosurgery after the onset of vomiting, headache and dizziness. A neurological deficit was detected during the physical examination so urgent magnetic resonance imaging of the brain was performed, revealing an intrahemispheric, right positioned solitary expansive mass with ring enhancement. Purulent material was obtained during osteoplastic craniotomy with total extirpation of the brain abscess. Aggregatibacter aphrophilus and Bacteroides uniformis were isolated. The patient's general condition improved and the neurological deficit subsided as a result of the prompt recognition and treatment of this life threatening condition.
CONCLUSION
To achieve a favourable clinical outcome, prompt recognition and surgical treatment of a brain abscess are of primary importance,followed by administration of appropriate antimicrobial therapy. To our best knowledge, this is the first report of this combination of microorganisms as the cause of a brain abscess.
Topics: Adolescent; Aggregatibacter aphrophilus; Anti-Bacterial Agents; Bacteroides; Bacteroides Infections; Brain Abscess; Cefixime; Ceftriaxone; Coinfection; Craniotomy; Drainage; Humans; Magnetic Resonance Imaging; Male; Metronidazole; Pasteurellaceae Infections
PubMed: 26702912
DOI: 10.5644/ama2006-124.144 -
Journal of Clinical Microbiology Jul 2018species are commensal bacteria of human mucosal surfaces that are sometimes involved in serious invasive infections. During the investigation of strains cultured from...
species are commensal bacteria of human mucosal surfaces that are sometimes involved in serious invasive infections. During the investigation of strains cultured from various clinical specimens, we encountered a coherent group of 10 isolates that could not be allocated to any validly named species by phenotype, mass spectrometry, or partial 16S rRNA gene sequencing. Whole-genome sequencing revealed a phylogenetic cluster related to but separate from The mean DNA hybridization value for strains of the new cluster versus was 56% (range, 53.7 to 58.0%), whereas the average nucleotide identity was 94.4% (range, 93.9 to 94.8%). The new cluster exhibited aggregative properties typical of the genus Key phenotypic tests for discrimination of the new cluster from validly named species are alanine-phenylalanine-proline arylamidase, -acetylglucosamine, and β-galactosidase. The name is proposed, with PN_528 (CCUG 70536 or DSM 105094) as the type strain.
Topics: Aggregatibacter; Comparative Genomic Hybridization; DNA, Bacterial; Genome, Bacterial; Humans; Pasteurellaceae Infections; Phenotype; Phylogeny; Sequence Analysis, DNA; Sequence Homology, Nucleic Acid; Species Specificity
PubMed: 29695522
DOI: 10.1128/JCM.00053-18 -
The Pan African Medical Journal 2018Liver abscess of oropharyngeal origin in an immunocompetent patient is a rare condition. Furthermore, microbiologic diagnosis of liver abscess can be challenging due to...
Liver abscess of oropharyngeal origin in an immunocompetent patient is a rare condition. Furthermore, microbiologic diagnosis of liver abscess can be challenging due to the tremendous diversity of the microorganisms implicated and culture difficulties under laboratory conditions. We report a case of a previously healthy 23-year-old male, who presented multiple liver abscesses, attributed to , an obligatory oral gram-negative microorganism, that normally is a component of the commensal oral microbiota and non-virulent. The etiopathogenic microorganism was identified after needle aspiration of a liver abscess cavity. Treatment with broad-spectrum antimicrobials and percutaneous catheter drainage under computed tomography guidance of both abscesses, resulted in full recovery. represents a rare entity of liver abscess in healthy individuals and suggests that a pathogen of oropharyngeal origin should be suspected when an overt source of infection cannot be documented.
Topics: Aggregatibacter aphrophilus; Anti-Bacterial Agents; Drainage; Humans; Liver Abscess; Male; Pasteurellaceae Infections; Tomography, X-Ray Computed; Young Adult
PubMed: 31037175
DOI: 10.11604/pamj.2018.31.115.16409 -
Journal of Microbiology, Immunology,... Oct 2012Aggregatibacter aphrophilus (formerly Haemophilus aphrophilus/paraphrophilus) is a small Gram-negative coccobacillus with fastidious growth requirements. It is a normal...
Aggregatibacter aphrophilus (formerly Haemophilus aphrophilus/paraphrophilus) is a small Gram-negative coccobacillus with fastidious growth requirements. It is a normal commensal of the human oropharynx and upper respiratory tract, and it can infrequently cause invasive human diseases, including bone and joint infections and subacute infective endocarditis. Cases of liver abscess caused by Aggregatibacter aphrophilus have been sparsely recorded in the English-language literature, but have not yet been reported in Taiwan. Here we present a case of Aggregatibacter aphrophilus pyogenic liver abscess in an immunocompetent young woman. She recovered uneventfully after repeated percutaneous abscess aspiration and antibiotic treatment for 5 weeks.
Topics: Adult; Anti-Bacterial Agents; Female; Humans; Liver; Liver Abscess, Pyogenic; Pasteurellaceae; Pasteurellaceae Infections; Radiography, Abdominal; Suction; Taiwan; Tomography, X-Ray Computed; Treatment Outcome; Ultrasonography
PubMed: 22622257
DOI: 10.1016/j.jmii.2011.12.004 -
BMC Infectious Diseases May 2022The bacterial genus Aggregatibacter was categorized in 2006 to accommodate the former Actinobacillus actinomycetemcomitans, Haemophilus aphrophilus, and H. segnis...
BACKGROUND
The bacterial genus Aggregatibacter was categorized in 2006 to accommodate the former Actinobacillus actinomycetemcomitans, Haemophilus aphrophilus, and H. segnis species. Aggregatibacter kilianii is a normal resident of the human upper respiratory tract but can also cause serious infections. A. kilianii is relatively newly identified and has been isolated from conjunctivitis, wounds, abdominal abscesses, and blood.
CASE PRESENTATION
An 80-year-old female patient with distal common bile duct cancer was admitted to our hospital with sudden loss of consciousness and general weakness, fever, and abdominal pain for 3 days. Two colonial morphologies were isolated from both the blood and bile cultures; one was identified as Streptococcus constellatus subsp. pharyngis, but the other was not recognized by Vitek2 and MALDI-TOF. The 16 S rRNA sequences showed 99.73% similarity with the sequence of A. kilianii strains.
CONCLUSION AND DISCUSSION
This article presents the first case of a clinical isolate of A. kilianii outside Europe. This case is also the first of the antimicrobial profile of this strain. This report highlights the importance of proper molecular identification for timely diagnosis and treatment of disease.
Topics: Aged, 80 and over; Aggregatibacter; Aggregatibacter aphrophilus; Female; Humans; Streptococcus
PubMed: 35619055
DOI: 10.1186/s12879-022-07471-7