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The American Journal of Case Reports May 2019BACKGROUND Aerococcus viridans are Gram-positive, catalase and oxidase-negative, microaerophilic, and non-motile bacteria species that are rarely associated with human... (Review)
Review
BACKGROUND Aerococcus viridans are Gram-positive, catalase and oxidase-negative, microaerophilic, and non-motile bacteria species that are rarely associated with human infections such as arthritis, bacteremia, endocarditis, and meningitis. The bacteria are also fastidious (i.e., have complex nutritional requirements) and often confused with Streptococci species or treated as a contaminant. CASE REPORT We report a case of Aerococcus septicemia in an 85-year-old female patient, who transferred from a nursing home to an acute care hospital in Washington DC, USA. She had a 2-day history of worsening mental status, fever of 38.9°C (102°F), and tachycardia. Urinalysis revealed numerous white blood cells and bacteria. Laboratory tests revealed a white blood cell count of 14 000 cells/mL (85% neutrophils, 8% lymphocytes, 5% bands, and 2% monocytes), hemoglobin of 12.6 g/dL, and serum creatinine of 0.8 mg/dL. Blood and urine cultures obtained during admission grew penicillin-resistant A. viridans, identified via matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF) on day 3 of admission. The patient received empiric vancomycin with piperacillin-tazobactam, and we deescalated to vancomycin monotherapy to complete a 14-day treatment course. CONCLUSIONS This case report highlights the role of MALDI-TOF for identifying fastidious organisms, and we were able to form a better clinical correlation between patient symptoms and causative organisms. We believe that antimicrobial therapy (in accordance with susceptibility results) should be initiated in symptomatic patients who have A. viridans isolated in significant amounts in urine or from a sterile site.
Topics: Aerococcus; Aged, 80 and over; Female; Gram-Positive Bacterial Infections; Humans; Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization
PubMed: 31089069
DOI: 10.12659/AJCR.914866 -
Microorganisms Nov 2021The investigation of bacterial microbiota represents a developing research field in veterinary medicine intended to look for correlations between animal health and the...
The investigation of bacterial microbiota represents a developing research field in veterinary medicine intended to look for correlations between animal health and the balance within bacterial populations. The aim of the present work was to define the bacterial microbiota of the oral cavity of healthy sows, which had not been thoroughly described so far. In total, 22 samples of oral fluid were collected and analyzed by 16S-rRNA gene sequencing. CLC Genomics Workbench 20.0 (QIAGEN Digital Insights, Aarhus, Denmark) was then used to examine the results. The predominant orders were Lactobacillales, Clostridiales, and Corynebacteriales. Lactobacillaceae, Corynebacteriaceae, Moraxellaceae, Aerococcaceae, and Staphylococcaceae were the most represented families. As regards the most abundant genera, , , , , , , and can be pointed out as the bacterial core microbiota. Sows were also divided into "gestating" and "lactating" groups, and mild differences were found between pregnant and lactating sows. The data herein described represent an original contribution to the knowledge of the porcine bacterial microbiota. Moreover, the choice of sows as experimental animals was strategic for identifying the adult microbial community. These data provide a basis for further studies on the oral bacterial microbiota of pigs.
PubMed: 34835441
DOI: 10.3390/microorganisms9112314 -
International Journal of Infectious... Jan 2021We describe our multicenter experience on diagnosis and management of Aerococcus bacteremia including the susceptibility profile of Aerococcus species and a suggested...
OBJECTIVES
We describe our multicenter experience on diagnosis and management of Aerococcus bacteremia including the susceptibility profile of Aerococcus species and a suggested algorithm for clinicians.
METHODS
Retrospective study of all patients with positive blood cultures for Aerococcus species from January 2005 to July 2020 in our institution with clinical data and susceptibility profile. Data were collected from both electronic health record and clinical microbiology laboratory database.
RESULTS
There were 219 unique isolates with only the susceptibility profiles available, while 81 patients had clinical information available. Forty-nine of those cases were deemed as true bloodstream infection and the rest were of unclear clinical significance. Cases of endocarditis (n = 7) were high-grade, monomicrobial bacteremia caused by Aerococcus urinae. Patients with endocarditis were younger (66 vs 80 p < 0.05). The risk for endocarditis was higher if duration of symptoms was longer than 7 days (OR 105, 95% CI: 5-2271), or if there were septic emboli (OR 71, 95% CI: 3-1612). A DENOVA score cutoff of ≥ 3 was 100% sensitive and 89% specific in detecting endocarditis. The 30-day and 3-month all-cause mortality for bacteremia was 17% and 24%, respectively. Six out of seven patients with endocarditis survived.
CONCLUSIONS
Antibiotic regimen for aerococcal bloodstream infections and endocarditis should be guided by species identification and antimicrobial susceptibility testing. DENOVA scoring system's performance in this study is more congruent to other studies. Hence, it can be used as an adjunctive tool in assessing the need for echocardiogram to rule out endocarditis. In our experience, two and four weeks of treatment for bloodstream infections and endocarditis, respectively, had good outcomes.
Topics: Adult; Aerococcus; Aged; Aged, 80 and over; Anti-Bacterial Agents; Bacteremia; Endocarditis, Bacterial; Female; Gram-Positive Bacterial Infections; Humans; Male; Microbial Sensitivity Tests; Middle Aged; Retrospective Studies; Sepsis; Young Adult
PubMed: 33157289
DOI: 10.1016/j.ijid.2020.10.096 -
Journal of Biotechnology Feb 2024l-Lactate oxidase has important applications in biosensing and finds increased use in biocatalysis. The enzyme has been characterized well, yet its immobilization has...
l-Lactate oxidase has important applications in biosensing and finds increased use in biocatalysis. The enzyme has been characterized well, yet its immobilization has not been explored in depth. Here, we studied immobilization of Aerococcus viridansl-lactate oxidase on porous carriers of variable matrix material (polymethacrylate, polyurethane, agarose) and surface functional group (amine, Ni-loaded nitrilotriacetic acid (NiNTA), epoxide). Carrier activity (A) and immobilized enzyme effectiveness (ɳ) were evaluated in dependence of protein loading. Results show that efficient immobilization (A: up to 1450 U/g carrier; ɳ: up to 65%) requires a hydrophilic carrier (agarose) equipped with amine groups. The value of ɳ declines sharply as A increases, probably due to transition into diffusional regime. Untagged l-lactate oxidase binds to NiNTA carrier similarly as N-terminally His-tagged enzyme. Lixiviation studies reveal quasi-irreversible enzyme adsorption on NiNTA carrier while partial release of activity (≤ 25%) is shown from amine carrier. The desorbed enzyme exhibits the same specific activity as the original l-lactate oxidase. Collectively, our study identifies basic requirements of l-lactate oxidase immobilization on solid carrier and highlights the role of ionic interactions in enzyme-surface adsorption.
Topics: Aerococcus; Sepharose; Mixed Function Oxygenases; Enzymes, Immobilized; Amines
PubMed: 38280467
DOI: 10.1016/j.jbiotec.2024.01.011 -
Journal of Dental Research Jan 2016The oral microbiota was compared between Romanian adolescents with a high prevalence of caries and no dental care and Swedish caries-active and caries-free adolescents... (Comparative Study)
Comparative Study
The oral microbiota was compared between Romanian adolescents with a high prevalence of caries and no dental care and Swedish caries-active and caries-free adolescents in caries prevention programs and with a low prevalence of caries. Biofilm samples were analyzed by FLX+ pyrosequencing of the V1 to V4 hypervariable regions of the 16S rRNA gene and polymerase chain reaction (PCR)/quantitative PCR (qPCR) for Streptococcus mutans and Streptococcus sobrinus. Sequences obtained blasted to 9 phyla, 66 genera, and 401 human oral taxa (HOT) in the 16S rRNA Human Oral Microbiome Database, of which 295 were represented by ≥20 sequences. The Romanian adolescents had more sequences in Firmicutes and fewer in Actinobacteria phyla and more sequences in the genera Bacteroidetes [G-3], Porphyromonas, Abiotrophia, Filifactor, Peptostreptococcaceae [11][G-4], Pseudoramibacter, Streptococcus, and Neisseria and fewer in Actinomyces, Selenomonas, Veillonella, Campylobacter, and TM7 [G-1] than the Swedish groups. Multivariate modeling employing HOT, S. sobrinus and S. mutans (PCR/qPCR), and sugar snacks separated Romanian from Swedish adolescents. The Romanian adolescents' microbiota was characterized by a panel of streptococci, including S. mutans, S. sobrinus, and Streptococcus australis, and Alloprevotella, Leptotrichia, Neisseria, Porphyromonas, and Prevotella. The Swedish adolescents were characterized by sweet snacks, and those with caries activity were also characterized by Prevotella, Actinomyces, and Capnocytophaga species and those free of caries by Actinomyces, Prevotella, Selenomonas, Streptococcus, and Mycoplasma. Eight species including Streptococcus mitis and Streptococcus species HOT070 were prevalent in Romanian and Swedish caries-active subjects but not caries-free subjects. In conclusion, S. mutans and S. sobrinus correlated with Romanian adolescents with caries and with limited access to dental care, whereas S. mutans and S. sobrinus were detected infrequently in Swedish adolescents in dental care programs. Swedish caries-active adolescents were typically colonized by Actinomyces, Selenomonas, Prevotella, and Capnocytophaga. Hence, the role of mutans streptococci as a primary caries pathogen appears less pronounced in populations with prevention programs compared to populations lacking caries treatment and prevention strategies.
Topics: Abiotrophia; Actinobacteria; Actinomyces; Adolescent; Bacteroidetes; Biofilms; Campylobacter; Capnocytophaga; DMF Index; Dental Care; Dental Caries; Eubacterium; Fusobacteria; Gram-Negative Bacteria; Humans; Microbiota; Neisseria; Peptostreptococcus; Porphyromonas; Prevotella; Selenomonas; Snacks; Streptococcus; Streptococcus mutans; Streptococcus sobrinus; Veillonella
PubMed: 26442950
DOI: 10.1177/0022034515609554 -
Biochemical and Biophysical Research... Sep 2021The crystal structure of l-lactate oxidase in complex with l-lactate was solved at a 1.33 Å resolution. The electron density of the bound l-lactate was clearly shown...
The crystal structure of l-lactate oxidase in complex with l-lactate was solved at a 1.33 Å resolution. The electron density of the bound l-lactate was clearly shown and comparisons of the free form and substrate bound complexes demonstrated that l-lactate was bound to the FMN and an additional active site within the enzyme complex. l-lactate interacted with the related side chains, which play an important role in enzymatic catalysis and especially the coupled movement of H265 and D174, which may be essential to activity. These observations not only reveal the enzymatic mechanism for l-lactate binding but also demonstrate the dynamic motion of these enzyme structures in response to substrate binding and enzymatic reaction progression.
Topics: Aerococcus; Bacterial Proteins; Binding Sites; Catalytic Domain; Crystallography, X-Ray; Hydrogen-Ion Concentration; Lactic Acid; Mixed Function Oxygenases; Models, Molecular; Substrate Specificity
PubMed: 34214876
DOI: 10.1016/j.bbrc.2021.06.078 -
BMC Microbiology Nov 2020Microencapsulated organic acids and botanicals have the potential to develop into important tools for the poultry industry. A blend of organic acids and botanicals...
BACKGROUND
Microencapsulated organic acids and botanicals have the potential to develop into important tools for the poultry industry. A blend of organic acids and botanicals (AviPlus®P) has previously shown to reduce Salmonella and Campylobacter in chickens; however, changes to the microbiota of the jejunum and ileum have not been evaluated. Microbiota diversity is linked to, but not correlated with, the efficacy of natural products; therefore, understanding the effects on the microbiota is necessary for evaluating their potential as an antibiotic alternative.
RESULTS
Ileal and jejunal segments from control and supplement-fed chickens (300 and 500 g/metric ton [MT]) were subjected to alpha diversity analysis including Shannon's diversity and Pielou's Evenness. In both analytics, the diversity in the ileum was significantly decreased compared to the jejunum irrespective of treatment. Similarly, beta diversity metrics including Bray-Curtis dissimilarity index and Weighted Unifrac Distance Matrix, were significant (Q < 0.05) for both tissue and treatments comparisons. Alpha and beta diversity analytics indicated compartmentalization effects between the ileum and jejunum. Additionally, analysis of communities in the microbiota (ANCOM) analysis showed Lactobacilliaceae predominated the total operational taxonomic units (OTU), with a stepwise increase from 53% in the no treatment control (NTC) to 56% in the 300 g/MT and 67% in the 500 g/MT group. Staphylococcaceae were 2% in NTC and 2 and 0% in 300 and 500 g/MT groups. Enterobacteriaceae decreased in the 500 g/MT (31%) and increased in the 300 g/MT (37%) compared to the NTC (35%). Aerococcaceae was 0% for both doses and 7% in NTC. Ruminococcaceae were 0% in NTC and 2 and 1% in the 300 and 500 g/MT. These changes in the microbial consortia were statistically (Q < 0.05) associated with treatment groups in the jejunum that were not observed in the ileum. Least discriminant analysis effect size (LEfSE) indicated different changes directly corresponding to treatment. Enterobacteriaceae demonstrated a stepwise decrease (from NTC onward) while Clostridiaceae, were significantly increased in the 500 g/MT compared to NTC and 300 g/MT (P < 0.05).
CONCLUSION
The bioactive site for the microencapsulated blend of organic acids and botanicals was the jejunum, and dietary inclusion enhanced the GIT microbiota and may be a viable antibiotic alternative for the poultry industry.
Topics: Acids; Animal Feed; Animals; Antineoplastic Agents, Phytogenic; Bacteria; Chickens; Diet; Dietary Supplements; Gastrointestinal Microbiome; Ileum; Jejunum; RNA, Ribosomal, 16S
PubMed: 33138790
DOI: 10.1186/s12866-020-02001-4 -
The American Journal of Case Reports Oct 2022BACKGROUND Aerococcus species are a rare cause of endocarditis. Micro-organism identification and antibiotic choice can pose significant management challenges to...
BACKGROUND Aerococcus species are a rare cause of endocarditis. Micro-organism identification and antibiotic choice can pose significant management challenges to clinicians who care for patients with this infection. Aerococcus is a gram-positive micro-organism which is commonly misidentified because it shares many similarities with streptococcus and enterococcus species. Aerococcus urinae is usually found to cause urinary tract infections and occurs more frequently in patients with structural urinary tract abnormalities associated with urethral and ureteral obstruction such as kidney stones, phimosis, and prostate hyperplasia. However, it is reported to rarely cause endocarditis. CASE REPORT A 48-year-old man with a history of cocaine abuse and right hip replacement presented to our emergency department with acute encephalopathy. Through a complicated hospital course, he was found to be septic and the bacteria were initially misidentified as an alpha-hemolytic strep before being correctly identified as Aerococcus urinae. He was found to have multiple cerebral, likely septic, embolic infarcts and aortic valve endocarditis. Identification of the micro-organism on blood cultures was challenging, as were decisions about antibiotic choice. He died despite efforts of a multidisciplinary care team. CONCLUSIONS Our case highlights a unique case of Aerococcus endocarditis and shows the difficulty in initially identifying the bacteria. To our knowledge this is the first case reported in the setting of substance abuse. It also highlights the lack of appropriate guideline-directed therapy with regards to antibiotic choices in this group of patients, emphasizing the importance of further research in this regard.
Topics: Aerococcus; Anti-Bacterial Agents; Aortic Valve; Endocarditis; Endocarditis, Bacterial; Gram-Positive Bacterial Infections; Humans; Male; Middle Aged; Sepsis
PubMed: 36251625
DOI: 10.12659/AJCR.937596 -
Annals of Clinical Microbiology and... Feb 2022Pyelonephritis is one of the most serious bacterial illnesses during childhood. Gram-negative organisms account for up to 90% of the cases. Gram-positive bacteria are... (Review)
Review
BACKGROUND
Pyelonephritis is one of the most serious bacterial illnesses during childhood. Gram-negative organisms account for up to 90% of the cases. Gram-positive bacteria are uncommon causes of urinary tract infections, and only a few cases caused by Facklamia hominis have been reported in the literature.
CASE PRESENTATION
A five-year-old girl with tracheostomy and gastrostomy and past medical history of congenital lymphangioma presented with a two-week history of with intermittent fever, frequent urination, and vesical tenesmus. Diagnosis of pyelonephritis was made. Urine culture reported colonies with alpha-hemolysis in blood agar at 48-h of incubation and Facklamia hominis was identified by MALDI-TOF. The patient was successfully treated with gentamicin.
CONCLUSIONS
This is the first reported case of pyelonephritis by Facklamia hominis in a child, and the second involving infection in a pediatric patient. Although this pathogen is uncommon, current treatment of F. hominis is a challenge for physicians. This case illustrates the requirement to standardize identification and treatment of care to avoid treatment failure and antimicrobial resistance.
Topics: Aerococcaceae; Anti-Bacterial Agents; Child, Preschool; Female; Fever; Gentamicins; Humans; Pyelonephritis; Treatment Outcome; Urinary Tract Infections
PubMed: 35151319
DOI: 10.1186/s12941-022-00497-4 -
Ophthalmic Surgery, Lasers & Imaging... Jun 2021To report the incidence and clinical features of infectious endophthalmitis after intravitreal (IV) injection of anti-vascular endothelial growth factor inhibitors...
BACKGROUND AND OBJECTIVE
To report the incidence and clinical features of infectious endophthalmitis after intravitreal (IV) injection of anti-vascular endothelial growth factor inhibitors (VEGF) between 2018 and 2020 and to compare to prior rates.
PATIENTS AND METHODS
Retrospective analysis of patients with endophthalmitis after anti-VEGF IV injections treated at Bascom Palmer Eye Institute between January 1, 2018, and December 31, 2020.
RESULTS
Between 2018 and 2020, the rate of clinically diagnosed endophthalmitis was 0.014% (10/71,858) and of culture-positive was 0.008% (6/71,858). Clinically diagnosed endophthalmitis rates per injection were: aflibercept (0.022%); ranibizumab (0.019%); bevacizumab (0%); and brolucizumab (0%). Clinically diagnosed endophthalmitis rates were similar in the present study compared to those from 2005 to 2017 ( = .84). Fifteen eyes were diagnosed with endophthalmitis (10 in-house, five external referrals). Of culture-positive eyes, the organisms were coagulase-negative (8/11), species (2/11), and (1/11). A universal face-masking policy in 2020 did not lower infection rates ( = .73).
CONCLUSION
Endophthalmitis rates after IV anti-VEGF remain low and are similar to prior reports. .
Topics: Abiotrophia; Angiogenesis Inhibitors; Bevacizumab; Endophthalmitis; Eye Infections, Bacterial; Humans; Incidence; Intravitreal Injections; Ranibizumab; Retrospective Studies; Tertiary Care Centers; Vascular Endothelial Growth Factor A
PubMed: 34185586
DOI: 10.3928/23258160-20210528-04