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Microbiology Spectrum Apr 2024and are two of the most common bacterial genera in the human oral cavity, encompassing both commensals and pathogens of substantial ecological and medical...
UNLABELLED
and are two of the most common bacterial genera in the human oral cavity, encompassing both commensals and pathogens of substantial ecological and medical significance. In this study, we conducted a metapangenomic analysis of oral and species to uncover genomic diversity, phylogenetic relationships, and habitat specialization within the human oral cavity. Using three metrics-pangenomic gene content, phylogenomics, and average nucleotide identity (ANI)-we first identified distinct species and sub-species groups among these genera. Mapping of metagenomic reads then revealed clear patterns of habitat specialization, such as species predominantly in dental plaque, a distinctive sub-species group on the tongue dorsum, and . sp. HMT-036 predominantly in keratinized gingiva and buccal mucosa. In addition, we found that supragingival plaque samples contained predominantly only one out of the three taxa, , , and . sp. HMT-458, suggesting independent niches or a competitive relationship. Functional analyses revealed the presence of key metabolic genes, such as oxaloacetate decarboxylase, correlated with habitat specialization, suggesting metabolic versatility as a driving force. Additionally, heme synthesis distinguishes . sp. HMT-036 from closely related , suggesting that the availability of micronutrients, particularly iron, was important in the evolutionary ecology of these species. Overall, our study exemplifies the power of metapangenomics to identify factors that may affect ecological interactions within microbial communities, including genomic diversity, habitat specialization, and metabolic versatility.
IMPORTANCE
Understanding the microbial ecology of the mouth is essential for comprehending human physiology. This study employs metapangenomics to reveal that various and species exhibit distinct ecological preferences within the oral cavity of healthy individuals, thereby supporting the site-specialist hypothesis. Additionally, it was observed that the gene pool of different species correlates with their ecological niches. These findings shed light on the significance of key metabolic functions in shaping microbial distribution patterns and interspecies interactions in the oral ecosystem.
Topics: Humans; Aggregatibacter; Phylogeny; Ecosystem; Haemophilus; Mouth
PubMed: 38488280
DOI: 10.1128/spectrum.04017-23 -
Antibiotics (Basel, Switzerland) Feb 2022The Aggregatibacter actinomycetemcomitans JP2 genotype is associated with high leukotoxin production and severe (aggressive) periodontitis. The aim of this study was to...
The Aggregatibacter actinomycetemcomitans JP2 genotype is associated with high leukotoxin production and severe (aggressive) periodontitis. The aim of this study was to compare the antimicrobial susceptibility of JP2 and non-JP2 genotype strains. Minimal inhibitory concentrations (MICs) of 11 antimicrobials were determined for 160 A. actinomycetemcomitans of serotype a, b, or c, mostly isolated in Sweden or Ghana. MIC distributions for benzylpenicillin and fusidic acid revealed a more susceptible subpopulation for 38 serotype b strains, including the 32 of the JP2 genotype, with a benzylpenicillin MIC range of 0.125−0.5 mg/L. In contrast, benzylpenicillin MIC ≤ 16 mg/L was the estimated 99.5% epidemiological cutoff (ECOFF) of all strains. Beta-lactamase production was not detected. The fusidic acid MIC distribution of 11 strains of Aggregatibacter aphrophilus agreed with that found in non-JP2 strains. Cefotaxime, meropenem, levofloxacin, and trimethoprim−sulfamethoxazole MICs were all ≤0.25 mg/L, while MIC90 values for amoxicillin, azithromycin and tetracycline were 1 mg/L. Metronidazole MICs varied between 0.5 and >256 mg/L. The discrepant findings indicate that A. actinomycetemcomitans may be divided into two separate wild types, with a suggested intrinsic reduced susceptibility for benzylpenicillin in the majority of non-JP2 genotype strains. Possible implications for the treatment of A. actinomycetemcomitans infections are discussed.
PubMed: 35326780
DOI: 10.3390/antibiotics11030317 -
International Journal of Surgery Case... 2017Aggregatibacter aphrophilus is a rare cause of infective endocarditis. This pathogen is difficult to identify with common culture methods, which can lead to incorrect...
INTRODUCTION
Aggregatibacter aphrophilus is a rare cause of infective endocarditis. This pathogen is difficult to identify with common culture methods, which can lead to incorrect diagnosis and treatment.
PRESENTATION OF CASE
A 72-year-old woman was admitted to a community hospital with a persistent high fever and deteriorating renal function. Based on negative blood culture and positive serum proteinase 3 anti-neutrophil cytoplasmic antibody (PR3-ANCA), acute renal failure associated with ANCA-rerated vasculitis was initially suspected. However, the patient developed heart failure soon afterward; echocardiography showed mitral insufficiency with mobile vegetation attached to the mitral valve, indicating infective endocarditis. After transfer to our hospital, the patient underwent mitral valve repair. Broad-range polymerase chain reaction (br-PCR) and sequencing identified Aggregatibacter aphrophilus in the excised vegetation. The patient had a good postoperative course, with recovery of renal function.
CONCLUSION
A rare disease, Aggregatibacter aphrophilus infective endocarditis was successfully treated with surgical repair and appropriate antibiotic therapy. To avoid misdiagnosis, br-PCR testing should be performed in patients with blood culture-negative endocarditis.
PubMed: 28152491
DOI: 10.1016/j.ijscr.2017.01.041 -
Klinische Padiatrie Mar 2015Uncommon microorganisms are increasingly being recognized as causative agents of paediatric infectious endocarditis (IE). We report a 4-year old girl with congenital...
Uncommon microorganisms are increasingly being recognized as causative agents of paediatric infectious endocarditis (IE). We report a 4-year old girl with congenital heart disease, who suffered from 2 IE episodes secondary to Aggregatibacter aphrophilus (formerly Haemophilus aphrophilus) and Staphylococcus lugdunensis, both rarely reported pathogens in this age group. The patient was initially successfully treated with prolonged intravenous antibiotic courses, however removal of the Contegra valved conduit during the second episode was required due to recurrence of fever and development of pulmonary embolism despite completion of antibiotic therapy. A. aphrohilus is a member of the fastidious gram negative microorganisms of the HACEK group (Haemophilus spp., Aggregatibacter spp, Cardiobaterium hominis, Eikenella corrodens and Kingella kingae), that colonize the oropharynx and are a recognised cause of IE. Prognosis of children with IE due to HACEK group members varies, half of them suffering from complications and mortality rates of 10-12.5%. Although S. lugdunensis belongs to coagulase negative staphylococci (CONS), it behaves more like S. aureus species rather than CONS. This microorganism is a well-described cause of endocarditis in adult patients, associated with high requirements of surgical procedures and mortality (42-78%). In conclusion, paediatric IE can be caused by uncommon microorganisms associated with severe complications and potential fatality. The isolation of S. lugdunensis or A. aphrophilus in febrile patients should be considered clinically relevant and cardiac involvement must be ruled out. Those patients with proved IE will require prolonged intravenous antibiotic courses and in complicated cases surgical intervention.
Topics: Aggregatibacter aphrophilus; Anti-Bacterial Agents; Child, Preschool; Echocardiography; Endocarditis, Bacterial; Female; Heart Defects, Congenital; Humans; Infusions, Intravenous; Long-Term Care; Pasteurellaceae Infections; Postoperative Complications; Rare Diseases; Recurrence; Staphylococcal Infections; Staphylococcus lugdunensis
PubMed: 25751682
DOI: 10.1055/s-0034-1398536 -
Medicina 2024Brain abscess is a focal suppurative process produced in most cases by bacterial agents. Aggregatibacter aphrophilus is a gram-negative bacteria belonging to the HACEK...
Brain abscess is a focal suppurative process produced in most cases by bacterial agents. Aggregatibacter aphrophilus is a gram-negative bacteria belonging to the HACEK group, which causes infective endocarditis, liver abscesses, among others. Brain abscesses secondary to this germ are rare and, in most cases, it is associated with contact with pets, poor dental hygiene or dental procedures. Treatment consists of drainage of the abscess (greater than 2.5 cm) combined with antibiotic therapy, ideally beta-lactams. The case of a 64-year-old male patient with no relevant history is here presented. He was admitted to the emergency service due to headache, hemianopsia of a week's duration and later tonic-clonic seizures, in whom imaging studies and culture of a brain lesion subsequently revealed a brain abscess due to A. aphrophilus. This case aims to illustrate about the rarity of this infection, because A. aphrophilus is a normal part of the oropharyngeal flora and respiratory tract, in which it rarely causes invasive bacteremia.
Topics: Brain Abscess; Humans; Male; Aggregatibacter aphrophilus; Middle Aged; Pasteurellaceae Infections; Anti-Bacterial Agents; Drainage
PubMed: 38683524
DOI: No ID Found -
International Ophthalmology Apr 2015We hereby report a case of endogenous endophthalmitis, presumably caused by a rare culprit-Aggregatibacter aphrophilus. A. aphrophilus is a member of the HACEK group, a...
We hereby report a case of endogenous endophthalmitis, presumably caused by a rare culprit-Aggregatibacter aphrophilus. A. aphrophilus is a member of the HACEK group, a group of fastidious Gram-negative bacteria with low pathogenicity and a rare cause of human infections. For ophthalmic infection, it has been reported to cause canaliculitis and exogenous endophthalmitis. A middle-aged gentleman with good past health presented with decreased vision (20/200) in his left eye. Other than fever, he was well on presentation, with no apparent focus of infection. Subsequently, he developed an episode of high fever reaching 39.2 °C, with CRP of 233 mg/L. CT abdomen showed presumed kidney abscess and a rare Gram-negative coccobacillus. A. aphrophilus [formerly Haemophilus aphrophilus (Nørskov-lauritsen and Kilian in Int J Syst Evol Microbiol 56:2135-2146, 2006)] was found in blood culture, Vitreous sample was analysed using 16S ribosomal DNA amplification but failed to identify the organism. After appropriate treatment, his vision improved drastically from 20/200 to 20/30. A. aphrophilus isolated from blood cultures during septicemia in a patient with kidney abscess may be associated with metastatic endophthalmitis, which may appear as a first sign. Our case demonstrates that with prompt diagnosis and appropriate treatment, visual prognosis of A. aphrophilus endophthalmitis can be promising.
Topics: Abscess; Aggregatibacter aphrophilus; Endophthalmitis; Humans; Kidney Diseases; Male; Middle Aged
PubMed: 25680418
DOI: 10.1007/s10792-015-0044-z -
Open Forum Infectious Diseases Apr 2015We report a case of brain and lung abscesses caused by Agreggatibacter aphrophilus in a 43-YEAR-OLD man with past history of splenectomy and drug addiction, in the...
We report a case of brain and lung abscesses caused by Agreggatibacter aphrophilus in a 43-YEAR-OLD man with past history of splenectomy and drug addiction, in the absence of endocarditis. Microbiological samples remain negatives and diagnosis was made by 16S rDNA PCR performance on abscess fluid for this coccobacillus that belongs to the HACEK group. The patient's clinical symptoms resolved within 6 weeks of treatment with cefotaxim.
PubMed: 26380332
DOI: 10.1093/ofid/ofv031 -
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 -
Microbiology Spectrum Dec 2022Growing evidence suggests that oral infections can modify the course of systemic diseases. To date, epidemiological data on microbial oral infections are scarce. Here,...
Growing evidence suggests that oral infections can modify the course of systemic diseases. To date, epidemiological data on microbial oral infections are scarce. Here, we performed a comprehensive analysis of the trend and microbial diversity in oral infection specimens referred for clinical microbiology analysis from 2010 to 2020. The microbes were isolated by culture and were identified via matrix-assisted laser desorption ionization-time of flight mass spectrometry technology (MALDI-TOF MS) throughout the study period. A total of 1,014 referred samples from dental clinics in Stockholm County with dentoalveolar abscesses and jaw osteomyelitis being the main reason were identified. Overall, the microbial composition was dominated by (51%), followed by (19%), (12%), and (5%). At the genus level, Streptococcus spp. (36%), spp. (18%), and Staphylococcus spp. (11%) were among the most frequently reported. Interestingly, a strong increase in trend was noted for Streptococcus anginosus, Streptococcus mitis, Streptococcus sanguinis, Eikenella corrodens, spp., Aggregatibacter aphrophilus, Staphylococcus epidermidis, and Granulicatella adiacens during the study time ( = 0.66 to 0.89, < 0.05), and a minor increase was noted for Enterococcus faecalis and Klebsiella spp., whereas steady levels were noted for most of the others. The present study shows the diversity of bacteria that have been involved in dental infections during the last decade in the capital of Sweden, as well as the emerging oral microbiota trend, with clear clinical implications on the oral-systemic link. Oral diseases and associated microbes are a risk factor for systemic diseases and can change the courses of these diseases. To date, epidemiological data on microbial oral infections are scarce, and longitudinal reports are lacking. We present for the first time the microbial composition of severe oral bacterial infections determined via the MALDI-TOF mass spectrometry technique in a comprehensive study between 2010 and 2020 (11 years) in Stockholm County. The trend and microbial diversity of oral infections were analyzed on referred clinical microbiological samples and were processed by standardized protocols. Trend increase was noted for Streptococcus anginosus, Streptococcus mitis, Streptococcus sanguinis, Eikenella corrodens, spp., Aggregatibacter aphrophilus, Staphylococcus epidermidis, Granulicatella adiacens, Enterococcus faecalis, and Klebsiella spp. Our results provide new insights into the diversity and trend of oral microbiota that were involved in serious oral infections over the past decade in the capital of Sweden and may influence the oral-systemic link.
Topics: Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; Bacteria; Carnobacteriaceae; Streptococcus; Streptococcus anginosus
PubMed: 36420577
DOI: 10.1128/spectrum.02487-22 -
Cureus Mar 2022, formerly known as , is one member of a group of bacteria referred to as HACEK (, , , , ) organisms. Infections from any of the HACEK organisms typically lead to very...
, formerly known as , is one member of a group of bacteria referred to as HACEK (, , , , ) organisms. Infections from any of the HACEK organisms typically lead to very poor outcomes and can be difficult to manage, especially when complicated by intracranial hemorrhage (ICH). HACEK organisms can also be difficult to grow on blood cultures, and is rarely seen, if at all. Traditionally, most laboratories follow an extended incubation protocol of 14 to 21 days to aid the growth of HACEK bacteria. Herein we report a case of infective endocarditis where resulted on blood culture in three days, in a patient with a right shoulder abscess, complicated by septic embolization leading to ICH. We explore a potential link between the prompt growth of on blood culture and the presence of the right shoulder abscess.
PubMed: 35464520
DOI: 10.7759/cureus.23107