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The Brazilian Journal of Infectious... 2018Herein we report the case of a 10-year-old boy with an autosomal mosaic mutation who developed bacteremia. The causative agent was identified as Moraxella osloensis by... (Review)
Review
Herein we report the case of a 10-year-old boy with an autosomal mosaic mutation who developed bacteremia. The causative agent was identified as Moraxella osloensis by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry and 16S rRNA gene sequencing. In the pediatric population, there have been 13 case reports of infection attributed to M. osloensis and this is the fifth reported case of pediatric bacteremia due to M. osloensis. After Moraxella species infection was confirmed, the patient recovered with appropriate antimicrobial therapy. It is important to consider that M. osloensis can cause serious infections, such as bacteremia, in otherwise healthy children.
Topics: Anti-Bacterial Agents; Bacteremia; Child; Humans; Male; Moraxella; Moraxellaceae Infections; Polymerase Chain Reaction; Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; Treatment Outcome
PubMed: 29409692
DOI: 10.1016/j.bjid.2017.10.008 -
International Journal of Surgery Case... 2017Moraxella osloensis is a gram-negative coccobacillus, that is saprophytic on skin and mucosa, and rarely causing human infections. Reported cases of human infections...
INTRODUCTION
Moraxella osloensis is a gram-negative coccobacillus, that is saprophytic on skin and mucosa, and rarely causing human infections. Reported cases of human infections usually occur in immunocompromised patients.
PRESENTATION OF CASE
We report the second case of M. osloensis-caused-osteomyelitis in literature, occurring in a young healthy man. The organism was identified by sequencing analysis of the 16S ribosomal RNA gene. Our patient was treated successfully with surgical debridement and intravenous third-generation cephalosporins.
DISCUSSION
M. osloensis has been rarely reported to cause local or invasive infections. Our case report is the second case in literature and it is different from the previously reported case in that our patient has no chronic medical problems, no history of trauma, with unique presentation and features on the MRI and intraoperative finding.
CONCLUSION
Proper diagnosis is essential for appropriate treatment of osteomyelitis. RNA gene sequence analysis is the primary method of M. osloensis diagnosis. M. osloensis is usually susceptible to simple antibiotics.
PubMed: 29078156
DOI: 10.1016/j.ijscr.2017.10.022 -
Microbiology Spectrum Apr 2022The gold standard for confirming bacterial infections is culture-positive, which has a long sample-to-result turnaround time and poor sensitivity for unculturable and...
The gold standard for confirming bacterial infections is culture-positive, which has a long sample-to-result turnaround time and poor sensitivity for unculturable and fastidious pathogens; therefore, it is hard to guide early, targeted antimicrobial therapy and reduce overuse of broad-spectrum antibiotics. Nanopore targeted sequencing (NTS) is reported to be advantageous in detection speed and range over culture in prior published reports. However, investigation of the clinical performance of NTS is deficient at present. Thus, we assessed the feasibility of NTS for the first time with cohort and systematic comparisons with traditional culture assays and PCR followed by Sanger sequencing. This retrospective study was performed on 472 samples, including 6 specimen types from 436 patients, to evaluate the clinical performance of NTS designed for identifying the microbial composition of various infections. Of these samples, 86.7% were found to be NTS positive, which was significantly higher than culture-positive (26.7%). A total of 425 significant human opportunistic bacteria and fungi detected by NTS were selected to go through validation with PCR followed by Sanger sequencing. The average accuracy rate was 85.2% (maximum 100% created by Cryptococcus neoformans, the last one 66.7% provided by both Staphylococcus haemolyticus and Moraxella osloensis, minimum 0% produced by Burkholderia cepacia). The accuracy rate also varied with sample type; the highest accuracy rate was found in pleural and ascites fluid (95.8%) followed by bronchoalveolar lavage fluid (88.7%), urine (86.8%), and wound secretions (85.0%), while the lowest was present in cerebrospinal fluid (58.8%). NTS had a diagnostic sensitivity of 94.5% and specificity of 31.8%. The positive and negative predictive values of NTS were 79.9% and 66.7%, respectively. For diagnosis of infectious diseases, the sensitivity was greatly increased by 56.7% in NTS compared with culture (94.5% vs 37.8%). Therefore, NTS can accurately detect the causative pathogens in infectious samples, particularly in pleural and ascites fluid, bronchoalveolar lavage fluid, urine, and wound secretions, with a short turnaround time of 8-14 h, and might innovatively contribute to personalizing antibiotic treatments for individuals with standardized protocols in clinical practices. Nanopore targeted sequencing (NTS) is reported to be advantageous in detection speed and range over culture in prior published reports. Investigation of the clinical performance of NTS is deficient at present. In our study, cohort and systematic comparisons among three assays (culture, NTS, and Sanger sequencing) were analyzed retrospectively for the first time. We found that NTS undoubtedly has incomparable advantages in accurately detecting the causative pathogens in infectious samples, particularly in pleural and ascites fluid, bronchoalveolar lavage fluid, urine, and wound secretions, with a short turnaround time of 8-14 h. For sterile specimens like blood and cerebrospinal fluid (CSF), the NTS outcomes should be validated using other nucleic acid based detection technology. Overall, NTS might innovatively contribute to guiding early, targeted antimicrobial therapy with lower cost and reduce overuse of broad-spectrum antibiotics.
Topics: Anti-Bacterial Agents; Ascites; Communicable Diseases; Humans; Nanopores; Retrospective Studies; Sensitivity and Specificity
PubMed: 35352939
DOI: 10.1128/spectrum.00270-22 -
Frontiers in Immunology 2023Microenvironmental factors, including microbe-induced inflammation and immune-checkpoint proteins that modulate immune cells have been associated with both cervical...
BACKGROUND
Microenvironmental factors, including microbe-induced inflammation and immune-checkpoint proteins that modulate immune cells have been associated with both cervical insufficiency and preterm delivery. These factors are incompletely understood. This study aimed to explore and compare interactions among microbiome and inflammatory factors, such as cytokines and immune-checkpoint proteins, in patients with cervical insufficiency and preterm birth. In particular, factors related to predicting preterm birth were identified and the performance of the combination of these factors was evaluated.
METHODS
A total of 220 swab samples from 110 pregnant women, prospectively recruited at the High-Risk Maternal Neonatal Intensive Care Center, were collected between February 2020 and March 2021. This study included 63 patients with cervical insufficiency receiving cerclage and 47 control participants. Endo- and exocervical swabs and fluids were collected simultaneously. Shotgun metagenomic sequencing for the microbiome and the measurement of 34 immune-checkpoint proteins and inflammatory cytokines were performed.
RESULTS
First, we demonstrated that immune-checkpoint proteins, the key immune-regulatory molecules, could be measured in endocervical and exocervical samples. Secondly, we identified significantly different microenvironments in cervical insufficiency and preterm birth, with precise cervical locations, to provide information about practically useful cervical locations in clinical settings. Finally, the presence of (odds ratio = 14.785; P = 0.037) and chemokine CC motif ligand 2 levels higher than 73 pg/mL (odds ratio = 40.049; P = 0.005) in endocervical samples were associated with preterm birth. Combining and chemokine CC motif ligand 2 yielded excellent performance for predicting preterm birth (area under the receiver operating characteristic curve = 0.846, 95% confidence interval = 0.733-0.925).
CONCLUSION
Multiple relationships between microbiomes, immune-checkpoint proteins, and inflammatory cytokines in the cervical microenvironment were identified. We focus on these factors to aid in the comprehensive understanding and therapeutic modulation of local microbial and immunologic compositions for the management of cervical insufficiency and preterm birth.
Topics: Immune Checkpoint Proteins; Humans; Female; Pregnancy; Microbiota; Cytokines; Premature Birth; Cerclage, Cervical; Cervix Uteri; Prospective Studies; Uterine Cervical Incompetence
PubMed: 37554329
DOI: 10.3389/fimmu.2023.1228647 -
The Journal of Clinical Endocrinology... Sep 2023Imbalance of the skin microbial community could impair skin immune homeostasis and thus trigger skin lesions. Dysbiosis of skin microbiome may be involved in the early...
CONTEXT
Imbalance of the skin microbial community could impair skin immune homeostasis and thus trigger skin lesions. Dysbiosis of skin microbiome may be involved in the early pathogenesis of diabetic foot (DF). However, the potential mechanism remains unclear.
OBJECTIVE
To investigate the dynamic composition and function of the foot skin microbiome with risk stratification for DF and assess whether dysbiosis of the skin microbiome induces diabetic skin lesions.
METHODS
We enrolled 90 consecutive subjects who were divided into 5 groups based on DF risk stratification: very low, low, moderate, and high risk for ulcers and a healthy control group. Integrated analysis of 16S ribosomal RNA and metagenomic sequencing of cotton swab samples was applied to identify the foot skin microbiome composition and functions in subjects. Then a mouse model of microbiota transplantation was used to evaluate the effects of the skin microbiome on diabetic skin lesions.
RESULTS
The results demonstrated that, with the progression of diabetic complications, the proportion of gram-negative bacteria in plantar skin increased. At the species level, metagenome sequencing analyses showed Moraxella osloensis to be a representative core strain in the high-risk group. The major microbial metabolites affecting diabetic skin lesions were increased amino acid metabolites, and antibiotic resistance genes in microorganisms were abundant. Skin microbiota from high-risk patients induced more inflammatory cell infiltration, similar to the lipopolysaccharide (LPS)-stimulated response, which was inhibited by Toll-like receptor 4 (TLR4) antagonists.
CONCLUSIONS
The skin microbiome in patients with diabetes undergoes dynamic changes at taxonomic and functional levels with the progression of diabetic complications. The increase in gram-negative bacteria on the skin surface through LPS-TLR4 signal transduction could induce inflammatory response in early diabetic skin lesions.
Topics: Mice; Animals; Humans; Diabetic Foot; Lipopolysaccharides; Toll-Like Receptor 4; Dysbiosis; Gram-Negative Bacteria; Risk Factors; RNA, Ribosomal, 16S; Diabetes Mellitus
PubMed: 36974462
DOI: 10.1210/clinem/dgad178 -
Microbiology Resource Announcements Apr 2020We report the complete genome sequence of strain YV1, which was isolated from a wastewater treatment plant in Australia. The YV1 genome comprises a 2,615,801-bp...
We report the complete genome sequence of strain YV1, which was isolated from a wastewater treatment plant in Australia. The YV1 genome comprises a 2,615,801-bp chromosome and four plasmids. strain YV1 displays the distinctive morphology of Eikelboom morphotype 1863.
PubMed: 32273350
DOI: 10.1128/MRA.00030-20 -
IDCases 2016We report a case of a 31 year old male with extensive subclinical sinusitis leading to erosion in the cribriform plate and subsequent meningitis caused by the organism...
We report a case of a 31 year old male with extensive subclinical sinusitis leading to erosion in the cribriform plate and subsequent meningitis caused by the organism . The patient presented to the emergency department with rapid onset confusion, neck stiffness and headache. Inflammatory markers, renal and liver function, and a chest radiograph were all normal. CT Head showed extensive polyp disease in the paranasal sinuses with expansion of the left frontal sinus and CT Sinuses revealed an area of low attenuation in the cribriform plate consistent with bony erosion. MRI Head showed thick loculated sinus inflammation. Lumbar puncture yielded CSF with a high white cell count of predominantly mononuclear cells, no visible organisms and an elevated protein. CSF microscopy, culture and viral PCR were not diagnostic, and so the CSF was sent for 16S rDNA PCR screening, which identified the rDNA of . is a rare cause of bacterial meningitis, with only a few reported cases. This case illustrates that sinusitis, while a common condition, when severe can predispose to intracranial infection with atypical and low virulence organisms such as species, which do not commonly cause invasive CNS disease. This case represents the first case of meningitis reported from the United Kingdom.
PubMed: 27695673
DOI: 10.1016/j.idcr.2016.08.007 -
Glycobiology Jan 2023Bacterial protein glycosylation is commonly mediated by oligosaccharyltransferases (OTases) that transfer oligosaccharides en bloc from preassembled lipid-linked...
Bacterial protein glycosylation is commonly mediated by oligosaccharyltransferases (OTases) that transfer oligosaccharides en bloc from preassembled lipid-linked precursors to acceptor proteins. Natively, O-linking OTases usually transfer a single repeat unit of the O-antigen or capsular polysaccharide to the side chains of serine or threonine on acceptor proteins. Three major families of bacterial O-linking OTases have been described: PglL, PglS, and TfpO. TfpO is limited to transferring short oligosaccharides both in its native context and when heterologously expressed in glycoengineered Escherichia coli. On the other hand, PglL and PglS can transfer long-chain polysaccharides when expressed in glycoengineered E. coli. Herein, we describe the discovery and functional characterization of a novel family of bacterial O-linking OTases termed TfpM from Moraxellaceae bacteria. TfpM proteins are similar in size and sequence to TfpO enzymes but can transfer long-chain polysaccharides to acceptor proteins. Phylogenetic analyses demonstrate that TfpM proteins cluster in distinct clades from known bacterial OTases. Using a representative TfpM enzyme from Moraxella osloensis, we determined that TfpM glycosylates a C-terminal threonine of its cognate pilin-like protein and identified the minimal sequon required for glycosylation. We further demonstrated that TfpM has broad substrate tolerance and can transfer diverse glycans including those with glucose, galactose, or 2-N-acetyl sugars at the reducing end. Last, we find that a TfpM-derived bioconjugate is immunogenic and elicits serotype-specific polysaccharide IgG responses in mice. The glycan substrate promiscuity of TfpM and identification of the minimal TfpM sequon renders this enzyme a valuable additional tool for expanding the glycoengineering toolbox.
Topics: Animals; Mice; Moraxellaceae; Escherichia coli; Phylogeny; Hexosyltransferases; Bacterial Proteins; Fimbriae Proteins; Polysaccharides; Bacteria
PubMed: 36239418
DOI: 10.1093/glycob/cwac070 -
PLoS Genetics May 2018Polymyxin is the last line of defense against severe infections caused by carbapenem-resistant gram-negative pathogens. The emergence of transferable MCR-1/2 polymyxin...
Polymyxin is the last line of defense against severe infections caused by carbapenem-resistant gram-negative pathogens. The emergence of transferable MCR-1/2 polymyxin resistance greatly challenges the renewed interest in colistin (polymyxin E) for clinical treatments. Recent studies have suggested that Moraxella species are a putative reservoir for MCR-1/2 genetic determinants. Here, we report the functional definition of ICR-Mo from M. osloensis, a chromosomally encoded determinant of colistin resistance, in close relation to current MCR-1/2 family. ICR-Mo transmembrane protein was prepared and purified to homogeneity. Taken along with an in vitro enzymatic detection, MALDI-TOF mass spectrometry of bacterial lipid A pools determined that the ICR-Mo enzyme might exploit a possible "ping-pong" mechanism to accept the phosphoethanolamine (PEA) moiety from its donor phosphatidylethanolamine (PE) and then transfer it to the 1(or 4')-phosphate position of lipid A via an ICR-Mo-bound PEA adduct. Structural decoration of LPS-lipid A by ICR-Mo renders the recipient strain of E. coli resistant to polymyxin. Domain swapping assays indicate that the two domains of ICR-Mo cannot be functionally-exchanged with its counterparts in MCR-1/2 and EptA, validating its phylogenetic position in a distinct set of MCR-like genes. Structure-guided functional mapping of ICR-Mo reveals a PE lipid substrate recognizing cavity having a role in enzymatic catalysis and the resultant conference of antibiotic resistance. Expression of icr-Mo in E. coli significantly prevents the formation of reactive oxygen species (ROS) induced by colistin. Taken together, our results define a member of a group of intrinsic colistin resistance genes phylogenetically close to the MCR-1/2 family, highlighting the evolution of transferable colistin resistance.
Topics: Anti-Bacterial Agents; Bacterial Proteins; Colistin; Drug Resistance, Bacterial; Ethanolamines; Membrane Proteins; Molecular Docking Simulation; Moraxella; Phosphatidylethanolamines; Phylogeny; Protein Binding; Substrate Specificity
PubMed: 29758020
DOI: 10.1371/journal.pgen.1007389 -
Case Reports in Nephrology 2018Peritonitis is a very serious complication encountered in patients undergoing peritoneal dialysis and healthcare providers involved in the management should be very...
Peritonitis is a very serious complication encountered in patients undergoing peritoneal dialysis and healthcare providers involved in the management should be very vigilant. Gram-positive organisms are the frequent cause of peritonitis compared to gram-negative organisms. There has been recognition of peritonitis caused by uncommon organisms because of improved microbiological detection techniques. We report a case of peritonitis caused by Moraxella osloensis (M. osloensis), which is an unusual cause of infections in humans. A 68-year-old male, who has been on peritoneal dialysis for 2 years, presented with abdominal pain and cloudy effluent. Peritoneal fluid analysis was consistent with peritonitis and peritoneal fluid culture grew gram-negative bacteria. M. osloensis was identified by 16 S PCR phenotypic and sequencing techniques. Patient responded well to the treatment, with intraperitoneal cephalosporin, and repeat peritoneal fluid culture yielded no growth. M. osloensis rarely causes infection in humans and responds well to treatment, as reported in literature.
PubMed: 30671269
DOI: 10.1155/2018/4968371