Lautropia mirabilis gen. nov., sp. nov., a gram-negative motile coccus with unusual morphology isolated from the human mouth

Lautropia mirabilis sepsis in immunodeficiency: first report and genomic features

PURPOSE

Lautropia mirabilis is a Gram-negative, facultative anaerobic coccus, which has been detected mainly in respiratory sites of immunodeficient patients suffering from HIV or cystic fibrosis. To date, knowledge about the pathogenicity of L. mirabilis is spare due to the small numbers of documented cases.

METHODS

We present a literature review and report the case of a 39-year-old female diagnosed with common variable immunodeficiency (CVID) with IgG and IgA deficiency suffering from a sepsis with L. mirabilis. As no fully closed L. mirabilis genome besides the type strain was available to date, we additionally performed complete genome sequencing of L. mirabilis.

RESULTS

The patient was admitted to our hospital with recurrent episodes of fever. Here, we detected L. mirabilis in two different blood cultures. The bacterium was tested susceptible to and treated with meropenem. As the origin of L. mirabilis sepsis, we observed an active periodontitis likely due to impaired IgA levels and mucosal insufficiency as a consequence of CVID. Whole genome sequencing of L. mirabilis revealed several genes important for host cell invasion and intracellular survival of the pathogen.

CONCLUSIONS

Our case highlights the importance of L. mirabilis in immunocompromised patients also in other compartments than the respiratory tract.

The effect of methylated phosphatidylethanolamine derivatives on the ionization properties of signaling phosphatidic acid

Phosphatidylethanolamine (PE) and Phosphatidylcholine (PC) are the most abundant glycerophospholipids in eukaryotic membranes. The differences in the physicochemical properties of their headgroups have contrasting modulatory effects on their interaction with intracellular macromolecules. As such, their overall impact on membrane structure and function differs significantly. Enzymatic methylation of PE's amine headgroup produces two methylated derivatives namely monomethyl PE (MMPE) and dimethyl PE (DMPE) which have physicochemical properties that generally range between that of PE and PC. Additionally, their influence on membrane properties differs from both PE and PC. Although variations in headgroup methylation have been reported to affect signaling pathways, the direct influence that these differences exert on the ionization properties of signaling phospholipids have not been investigated. Here, we briefly review membrane function and structure that are mediated by the differences in headgroup methylation between PE, MMPE, DMPE and PC. In addition, using ³¹P MAS NMR, we investigate the effect of these four phospholipids on the ionization properties of the ubiquitous signaling anionic lipid phosphatidic acid (PA). Our results show that PA's ionization properties are differentially affected by changes in phospholipid headgroup methylation. This could have important implications for PA-protein binding and hence physiological functions in cells where signaling events lead to changes in abundance of methylated PE derivatives in the membrane.

Tolerance to intraoral biofilms and their effectiveness in improving mouth dryness and modifying oral microbiota in patients with primary Sjögren's syndrome: "Predelfi study"

INTRODUCTION

Primary Sjögren's syndrome (pSS) is a systemic autoimmune disease characterized by exocrine gland dysfunction. No therapeutic strategy is sufficient on its own for the management of dry mouth and therapeutic innovations are required.

METHODS

This Predelfi study was a single-center, prospective, comparative, randomized, double-blind, cross-over controlled study with the primary objective of assessing the tolerance to and effectiveness of two adhesive biofilms (containing prebiotics and, sodium alginate, respectively) in patients with pSS and hyposialia (#NCT04206826 in ClinicalTrials.gov). Secondary objectives were to obtain initial data regarding the clinical effectiveness of such biofilms in the improvement of signs and symptoms related to dry mouth and potential changes in the oral microbiota. Ten pSS patients with pSS were included (9 females and 1 male) with a mean age of 58.1 ± 14.0 years.

RESULTS AND DISCUSSION

Tolerance to the prebiotic and sodium alginate biofilms was assessed by the patients (visual analog scale [VAS] score 66.7 and 87.6, respectively) and the practitioner (90 and 100, respectively). The absolute changes in the VAS scores at the start and end of each treatment period highlighted an improvement in mouth dryness for the sodium alginate versus the prebiotic biofilm. The VAS scores for other parameters (mouth burning sensation; taste alteration; chewing; swallowing and speech difficulties) remained globally comparable between the two groups. Unstimulated salivary flow showed no changes regardless of the biofilm used. Regarding the oral microbiota, the sodium alginate biofilm increased the abundance of the Treponema genus, whereas the use of the prebiotic biofilm as the first treatment increased the abundance of the genera Veillonella and Prevotella. Nevertheless, the prebiotic biofilm appeared to stimulate "milder" genera with regard to periodontal infections. Furthermore, pre-treatment with the prebiotic biofilm prevented the emergence of the Treponema genus induced by subsequent treatment with the sodium alginate biofilm, suggesting a potential protective effect.

Ecology, Not Host Phylogeny, Shapes the Oral Microbiome in Closely Related Species

Host-associated microbiomes are essential for a multitude of biological processes. Placed at the contact zone between external and internal environments, the little-studied oral microbiome has important roles in host physiology and health. Here, we investigate the roles of host evolutionary relationships and ecology in shaping the oral microbiome in three closely related gorilla subspecies (mountain, Grauer's, and western lowland gorillas) using shotgun metagenomics of 46 museum-preserved dental calculus samples. We find that the oral microbiomes of mountain gorillas are functionally and taxonomically distinct from the other two subspecies, despite close evolutionary relationships and geographic proximity with Grauer's gorillas. Grauer's gorillas show intermediate bacterial taxonomic and functional, and dietary profiles. Altitudinal differences in gorilla subspecies ranges appear to explain these patterns, suggesting a close connection between dental calculus microbiomes and the environment, likely mediated through diet. This is further supported by the presence of gorilla subspecies-specific phyllosphere/rhizosphere taxa in the oral microbiome. Mountain gorillas show a high abundance of nitrate-reducing oral taxa, which may promote adaptation to a high-altitude lifestyle by modulating blood pressure. Our results suggest that ecology, rather than evolutionary relationships and geographic distribution, shape the oral microbiome in these closely related species.

Subgingival Microbiome in Pregnancy and a Potential Relationship to Early Term Birth

Background

Periodontal disease in pregnancy is considered a risk factor for adverse birth outcomes. Periodontal disease has a microbial etiology, however, the current state of knowledge about the subgingival microbiome in pregnancy is not well understood.

Objective

To characterize the structure and diversity of the subgingival microbiome in early and late pregnancy and explore relationships between the subgingival microbiome and preterm birth among pregnant Black women.

Methods

This longitudinal descriptive study used 16S rRNA sequencing to profile the subgingival microbiome of 59 Black women and describe microbial ecology using alpha and beta diversity metrics. We also compared microbiome features across early (8-14 weeks) and late (24-30 weeks) gestation overall and according to gestational age at birth outcomes (spontaneous preterm, spontaneous early term, full term).

Results

In this sample of Black pregnant women, the top twenty bacterial taxa represented in the subgingival microbiome included a spectrum representative of various stages of biofilm progression leading to periodontal disease, including known periopathogens Porphyromonas gingivalis and Tannerella forsythia. Other organisms associated with periodontal disease reflected in the subgingival microbiome included several Prevotella spp., and Campylobacter spp. Measures of alpha or beta diversity did not distinguish the subgingival microbiome of women according to early/late gestation or full term/spontaneous preterm birth; however, alpha diversity differences in late pregnancy between women who spontaneously delivered early term and women who delivered full term were identified. Several taxa were also identified as being differentially abundant according to early/late gestation, and full term/spontaneous early term births.

Conclusions

Although the composition of the subgingival microbiome is shifted toward complexes associated with periodontal disease, the diversity of the microbiome remains stable throughout pregnancy. Several taxa were identified as being associated with spontaneous early term birth. Two, in particular, are promising targets of further investigation. Depletion of the oral commensal Lautropia mirabilis in early pregnancy and elevated levels of Prevotella melaninogenica in late pregnancy were both associated with spontaneous early term birth.

Regional discrepancy of microbial community structure in activated sludge system from Chinese WWTPs based on high-throughput 16S rDNA sequencing

Overall understanding of microbial community structure in activated sludge (AS) system at regional level is of great significance for operation regulation of wastewater treatment plants (WWTPs). In this study, 110 AS samples from 21 cities in different Chinese regions were analyzed based on high-throughput 16S ribosomal DNA (rDNA) sequencing to explore effects of different regions on microbial community structure. Results showed that the regions with different characteristics (south and north, coastal and inland, high GDP and low GDP) had great impact on AS bacterial community in China. Core bacterial communities (101 OTUs) in south China were more abundant than those in north China (49 OTUs), and many core species in south China were associated with nutrient removal. Coastal WWTPs possessed unique bacterial communities due to the influence of marine bacteria. Phyla Chloroflexi and Acidobacteria were observed to be main biomarkers in coastal WWTPs. Compared with low GDP regions, more diverse microbial community and effective wastewater treatment were discovered in high GDP regions, and environmental factor analysis suggested that they were mainly correlated with high capacity and influent TP in the WWTPs. β nearest taxon index (βNTI) analysis showed that microbial community assembly in the analyzed AS samples was dominated by deterministic factors (70.67%) and influent quality was observed to be main factor.

The active lung microbiota landscape of COVID-19 patients through the metatranscriptome data analysis

Introduction: With the outbreak of coronavirus disease 2019 (COVID-19) caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the interaction between the host and SARS-CoV-2 was widely studied. However, it is unclear whether and how SARS-CoV-2 infection affects lung microflora, which contribute to COVID-19 complications.

Methods: Here, we analyzed the metatranscriptomic data of bronchoalveolar lavage fluid (BALF) of 19 COVID-19 patients and 23 healthy controls from 6 independent projects and detailed the active microbiota landscape in both healthy individuals and COVID-19 patients.

Results: The infection of SARS-CoV-2 could deeply change the lung microbiota, evidenced by the α-diversity, β-diversity, and species composition analysis based on bacterial microbiota and virome. Pathogens (e.g., Klebsiella oxytoca causing pneumonia as well), immunomodulatory probiotics (e.g., lactic acid bacteria and Faecalibacterium prausnitzii, a butyrate producer), and Tobacco mosaic virus (TMV) were enriched in the COVID-19 group, suggesting a severe microbiota dysbiosis. The significant correlation between Rothia mucilaginosa, TMV, and SARS-CoV-2 revealed drastic inflammatory battles between the host, SARS-CoV-2, and other microbes in the lungs. Notably, TMV only existed in the COVID-19 group, while human respirovirus 3 (HRV 3) only existed in the healthy group. Our study provides insights into the active microbiota in the lungs of COVID-19 patients and would contribute to the understanding of the infection mechanism of SARS-CoV-2 and the treatment of the disease and complications.

Conclusion: SARS-COV-2 infection deeply altered the lung microbiota of COVID-19 patients. The enrichment of several other pathogens, immunomodulatory probiotics (lactic acid or butyrate producers), and TMV in the COVID-19 group suggests a complex and active lung microbiota disorder.

Sedimentary Nitrogen and Sulfur Reduction Functional-Couplings Interplay With the Microbial Community of Anthropogenic Shrimp Culture Pond Ecosystem

Sediment nitrogen and sulfur cycles are essential biogeochemical processes that regulate the microbial communities of environmental ecosystems, which have closely linked to environment ecological health. However, their functional couplings in anthropogenic aquaculture sedimentary ecosystems remain poorly understood. Here, we explored the sediment functional genes in shrimp culture pond ecosystems (SCPEs) at different culture stages using the GeoChip gene array approach with 16S amplicon sequencing. Dissimilarity analysis showed that the compositions of both functional genes and bacterial communities differed at different phases of shrimp culture with the appearance of temporal distance decay (p < 0.05). During shrimp culture, the abundances of nitrite and sulfite reduction functional genes decreased (p < 0.05), while those of nitrate and sulfate reduction genes were enriched (p < 0.05) in sediments, implying the enrichment of nitrites and sulfites from microbial metabolism. Meanwhile, nitrogen and sulfur reduction genes were found to be linked with carbon degradation and phosphorous metabolism (p < 0.05). The influence pathways of nutrients were demonstrated by structural equation modeling through environmental factors and the bacterial community on the nitrogen and sulfur reduction functions, indicating that the bacterial community response to environmental factors was facilitated by nutrients, and led to the shifts of functional genes (p < 0.05). These results indicate that sediment nitrogen and sulfur reduction functions in SCPEs were coupled, which are interconnected with the SCPEs bacterial community. Our findings will be helpful for understanding biogeochemical cycles in anthropogenic aquaculture ecosystems and promoting sustainable management of sediment environments through the framework of an ecological perspective.

The oral microbiome and inflammation in mild cognitive impairment

Inflammation and immune mechanisms are believed to play important roles in Alzheimer's disease pathogenesis. Research supports the link between poor oral health and Alzheimer's disease. Periodontal disease and dental caries represent the two most common infections of the oral cavity. This study focused on a precursor to Alzheimer's disease, mild cognitive impairment (MCI). Using 16S rRNA sequencing, we characterized and compared the oral microbiome of 68 older adults who met the criteria for MCI or were cognitively normal, then explored relationships between the oral microbiome, diagnostic markers of MCI, and blood markers of systemic inflammation. Two taxa, Pasteurellacae and Lautropia mirabilis were identified to be differentially abundant in this cohort. Although systemic inflammatory markers did not differentiate the two groups, differences in five cerebrospinal fluid inflammatory mediators were identified and had significant associations with MCI. Because inflammatory markers may reflect CNS changes, pursuing this line of research could provide opportunities for new diagnostic tools and illuminate mechanisms for prevention and mitigation of Alzheimer's disease.

Japanese subgingival microbiota in health vs disease and their roles in predicted functions associated with periodontitis

The present study aimed to identify and compare the microbial signatures between periodontally healthy and periodontitis subjects using 454 sequences of 16S rRNA genes. Subgingival plaque samples were collected from ten periodontally healthy subjects and ten matched chronic periodontitis patients. Bacterial DNA was extracted and next-generation sequencing of 16S rRNA genes was performed. The microbial composition differed between healthy subjects and periodontitis patients at all phylogenetic levels. Particularly, 16 species, including Lautropia mirabilis and Neisseria subflava predominated in healthy subjects, whereas nine species, including Porphyromonas gingivalis and Filifactor alocis predominated in periodontitis. UniFrac, a principal coordinate and network analysis, confirmed distinct community profiles in healthy subjects and periodontitis patients. Using predicted function profiling, pathways involved in phenylpropanoid, GPI-anchor biosynthesis, and metabolism of alanine, arginine, aspartate, butanoate, cyanoamino acid, fatty acid, glutamate, methane, proline, and vitamin B6 were significantly over-represented in periodontitis patients. These results highlight the oral microbiota alterations in microbial composition in periodontitis and suggest the genes and metabolic pathways associated with health and periodontitis. Our findings help to further elucidate microbial composition and interactions in health and periodontitis.

Lautropia dentalis sp. nov., Isolated from Human Dental Plaque of a Gingivitis Lesion

A novel Gram-stain-negative, motile, and facultative anaerobic coccus, strain ChDC F240^T was isolated from human subgingival dental plaque of a gingivitis lesion. The phylogenetic analysis based on the 16S ribosomal RNA gene (16S rDNA) sequence showed that the strain belonged to the genus Lautropia. 16S rDNA of strain ChDC F240^T had the highest similarity to that of Lautropia mirabilis ATCC 51599^T (98.8%). Major cellular fatty acids of strain ChDC F240^T were C_16:0 (43.9%) and C_16:1ω6C/C_16:1ω7C (38.1%). Draft genome of the strain was 3,834,139 bp in length and the G+C content was 65.0 mol%. Average nucleotide identity and genome-to-genome distance values between strain ChDC F240^T and L. mirabilis ATCC 51599 ^T were 81.99% and 28.50% (26.1-30.9%), respectively. These results reveal that strain ChDC F240^T is a novel species within the genus Lautropia, for which the name Lautropia dentalis sp. nov. is proposed; type strain is ChDC F240^T (= KCOM 2505^T = JCM 33297^T).

Effect of temperature on nitrogen removal and biological mechanism in an up-flow microaerobic sludge reactor treating wastewater rich in ammonium and lack in carbon source

Previous study has demonstrated that microaerobic process is effective in nitrogen removal from the wastewater with high ammonium and low carbon to nitrogen ratio. In the microaerobic system, synergistic action of anammox, ammonia oxidizing bacteria (AOB), nitrite oxidizing bacteria (NOB) and denitrifiers was the key issues to remove nitrogen from the wastewater rich in ammonium. Temperature has a significant effect on specific growth rate and activity of various nitrogen removal functional bacteria. In this study, the effect of temperature (35 °C-15 °C) on nitrogen removal were investigated in an up-flow microaerobic sludge reactor (UMSR) at the HRT of 8 h and reflux ratio of 45. Above 71.2% of total nitrogen (TN) and 80.7% of NH₄⁺ removal efficiencies were observed at the temperature no less than 17 °C. With the temperature further decreasing to 15 °C, denitrifiers still dominant the UMSR, but AOB, NOB and Candidatus Brocadia as the predominant anammox bacteria were inhibited revealed by high throughput sequencing, resulting in the decrease of TN and NH₄⁺ removal to 39.7% and 61.8%, respectively. Fortunately, when the temperature rebounded to 20 °C, a higher TN and NH₄⁺ removal of 81.2% and 97.3% were obtained again in the UMSR.

Cargo transport shapes the spatial organization of a microbial community

The human microbiome is an assemblage of diverse bacteria that interact with one another to form communities. Bacteria in a given community are arranged in a 3D matrix with many degrees of freedom. Snapshots of the community display well-defined structures, but the steps required for their assembly are not understood. Here, we show that this construction is carried out with the help of gliding bacteria. Gliding is defined as the motion of cells over a solid or semisolid surface without the necessity of growth or the aid of pili or flagella. Genomic analysis suggests that gliding bacteria are present in human microbial communities. We focus on Capnocytophaga gingivalis, which is present in abundance in the human oral microbiome. Tracking of fluorescently labeled single cells and of gas bubbles carried by fluid flow shows that swarms of C. gingivalis are layered, with cells in the upper layers moving more rapidly than those in the lower layers. Thus, cells also glide on top of one another. Cells of nonmotile bacterial species attach to the surface of C. gingivalis and are propelled as cargo. The cargo cell moves along the length of a C. gingivalis cell, looping from one pole to the other. Multicolor fluorescent spectral imaging of cells of different live but nonmotile bacterial species reveals their long-range transport in a polymicrobial community. A swarm of C. gingivalis transports some nonmotile bacterial species more efficiently than others and helps to shape the spatial organization of a polymicrobial community.

Quisquiliibacterium transsilvanicum gen. nov., sp. nov., a novel betaproteobacterium isolated from a waste-treating bioreactor

A new betaproteobacterium, CGI-09^T, was isolated from an activated sludge bioreactor which treated landfill leachate. Based on 16S rRNA gene sequence analysis, the new strain shared the highest pairwise similarity values with members of the order Burkholderiales: Derxia gummosa IAM 13946^T (family Alcaligenaceae), 93.7 % and Lautropia mirabilis DSM 11362^T (family Burkholderiaceae), 93.6 %. Cells of strain CGI-09^T were rod-shaped and non-motile. The new strain was oxidase and catalase positive and capable of reducing nitrate to nitrite. The predominant fatty acids were C16 : 1 ω7c, C16 : 0, cycloC17 : 0 and C18 : 1 ω7c, the major respiratory quinone was Q-8, and the detected polar lipids were phosphatidylglycerol, diphosphatidylglycerol, phosphatidylethanolamine and an unknown phospholipid. The G+C content of the genomic DNA of strain CGI-09^T was 70.2 mol%. The new bacterium can be distinguished from the members of genera Derxia and Lautropia based on its non-motile cells, arginine dihydrolase activity, its high cyclo C17 : 0 fatty acid content and the lack of hydroxy fatty acids. On the basis of the phenotypic, chemotaxonomic and molecular data, strain CGI-09^T is considered to represent a new genus and species within the family Burkholderiaceae, for which the name Quisquiliibacterium transsilvanicum gen. nov., sp. nov. is proposed. The type strain is CGI-09^T (=DSM 29781^T=JCM 31785^T).

Decreased concentration of serum melatonin in nighttime compared with daytime female medical technologists in South Korea

Working during the night can disrupt the normal circadian rhythm by altering the melatonin level. A low level of melatonin is associated with an increased risk of cancer, possibly by decreasing the expression of tumor-suppressor genes, such as p53. To determine whether nighttime work is associated with melatonin level in serum as well as the expression of related genetic markers, we enrolled 100 female nighttime medical technologists employed at a hospital in South Korea. Melatonin concentration and melatonin receptor 1 (MT1) expression were significantly lower in nighttime than in daytime workers (1.84 pg/mL versus 4.04 pg/mL; 1.16 versus 1.61, respectively). However, p53 expression showed no difference between the groups. In summary, nighttime work could be an important risk factor for circadian disruption, but not a direct risk factor for cancer in medical technologists in South Korea.

Mycoavidus cysteinexigens gen. nov., sp. nov., an endohyphal bacterium isolated from a soil isolate of the fungus Mortierella elongata

An endohyphal bacterium (strain B1-EBT) living in association with the fungus Mortierella elongata FMR23-6 I-B1 was isolated from a fungal cell homogenate and studied for its taxonomic allocation. Cells were Gram-stain-negative, rod-shaped, non-spore-forming, non-motile, and negative for oxidase and catalase. Strain B1-EBT required cysteine for growth and grew at temperatures between 4 and 35 °C. A comparative analysis of 16S rRNA gene sequences revealed that strain B1-EBT forms a distinct clade in the family Burkholderiaceae, encompassing a group of endosymbionts associated with several soil isolates of M. elongata. The most closely related genus is 'Candidatus Glomeribacter gigasporarum', an endosymbiont of the arbuscular mycorrhizal fungus Gigaspora margarita. The major cellular fatty acids of strain B1-EBT were C16 : 0, summed feature 3 (C16 : 1ω7c and C16 : 1ω6c) and summed feature 8 (C18 : 1ω7c or C18 : 1ω6c). Ubiquinone Q-8 was the only quinone detected. The major polar lipids were phosphatidylethanolamine, phosphatidylglycerol, diphosphatidylglycerol, an unknown aminophospholipid and two unknown aminolipids. The DNA G+C content was 49.8 mol%. On the basis of phenotypic, chemotaxonomic, and phylogenetic characteristics, strain B1-EBT represents a novel genus and novel species in the family Burkholderiaceae, for which the name Mycoavidus cysteinexigens gen. nov., sp. nov. is proposed. The type strain is B1-EBT ( = JCM 30646T = LMG 28693T = NBRC 110909T).

The Variability of the Order Burkholderiales Representatives in the Healthcare Units

BACKGROUND AND AIM

The order Burkholderiales became more abundant in the healthcare units since the late 1970s; it is especially dangerous for intensive care unit patients and patients with chronic lung diseases. The goal of this investigation was to reveal the real variability of the order Burkholderiales representatives and to estimate their phylogenetic relationships.

METHODS

16S rDNA and genes of the Burkholderia cenocepacia complex (Bcc) Multi Locus Sequence Typing (MLST) scheme were used for the bacteria detection.

RESULTS

. A huge diversity of genome size and organization was revealed in the order Burkholderiales that may prove the adaptability of this taxon's representatives. The following variability of the Burkholderiales in Russian healthcare units has been revealed: Burkholderiaceae (Burkholderia, Pandoraea, and Lautropia), Alcaligenaceae (Achromobacter), and Comamonadaceae (Variovorax). The Burkholderia genus was the most diverse and was represented by 5 species and 16 sequence types (ST). ST709 and 728 were transmissible and often encountered in cystic fibrosis patients and in hospitals. A. xylosoxidans was estimated by 15 genotypes. The strains of first and second ones were the most numerous.

CONCLUSIONS

Phylogenetic position of the genus Lautropia with smaller genome is ambiguous. The Bcc MLST scheme is applicable for all Burkholderiales representatives for resolving the epidemiological problems.

Comparisons of subgingival microbial profiles of refractory periodontitis, severe periodontitis, and periodontal health using the human oral microbe identification microarray

BACKGROUND

This study compared the subgingival microbiota of subjects with refractory periodontitis (RP) to those in subjects with treatable periodontitis (GRs = good responders) or periodontal health (PH) using the Human Oral Microbe Identification Microarray (HOMIM).

METHODS

At baseline, subgingival plaque samples were taken from 47 subjects with periodontitis and 20 individuals with PH and analyzed for the presence of 300 species by HOMIM. The subjects with periodontitis were classified as having RP (n = 17) based on mean attachment loss (AL) and/or more than three sites with AL >or=2.5 mm after scaling and root planing, surgery, and systemically administered amoxicillin and metronidazole or as GRs (n = 30) based on mean attachment gain and no sites with AL >or=2.5 mm after treatment. Significant differences in taxa among the groups were sought using the Kruskal-Wallis and chi(2) tests.

RESULTS

More species were detected in patients with disease (GR or RP) than in those without disease (PH). Subjects with RP were distinguished from GRs or those with PH by a significantly higher frequency of putative periodontal pathogens, such as Parvimonas micra (previously Peptostreptococcus micros or Micromonas micros), Campylobacter gracilis, Eubacterium nodatum, Selenomonas noxia, Tannerella forsythia (previously T. forsythensis), Porphyromonas gingivalis, Prevotella spp., Treponema spp., and Eikenella corrodens, as well as unusual species (Pseudoramibacter alactolyticus, TM7 spp. oral taxon [OT] 346/356, Bacteroidetes sp. OT 272/274, Solobacterium moorei, Desulfobulbus sp. OT 041, Brevundimonas diminuta, Sphaerocytophaga sp. OT 337, Shuttleworthia satelles, Filifactor alocis, Dialister invisus/pneumosintes, Granulicatella adiacens, Mogibacterium timidum, Veillonella atypica, Mycoplasma salivarium, Synergistes sp. cluster II, and Acidaminococcaceae [G-1] sp. OT 132/150/155/148/135) (P <0.05). Species that were more prevalent in subjects with PH than in patients with periodontitis included Actinomyces sp. OT 170, Actinomyces spp. cluster I, Capnocytophaga sputigena, Cardiobacterium hominis, Haemophilus parainfluenzae, Lautropia mirabilis, Propionibacterium propionicum, Rothia dentocariosa/mucilaginosa, and Streptococcus sanguinis (P <0.05).

CONCLUSION

As determined by HOMIM, patients with RP presented a distinct microbial profile compared to patients in the GR and PH groups.

Cellular fatty acid composition of Lautropia mirabilis

Ten strains of Lautropia mirabilis (ATCC 51599(T) and nine phenotypically similar clinical isolates) were examined for cellular fatty acid (CFA) composition to evaluate their chemical relatedness to known bacterial species and groups. The CFAs were liberated from whole cells by base hydrolysis, methylated, and analyzed by gas-liquid chromatography. CFA profiles were generated by using a commericial software package (MIDI, Newark, Del.). All strains tested had an identical CFA profile characterized by major amounts of 16:1omega7c (41%) and 16:0 (44%); smaller amounts (1 to 4%) of 3-OH-10:0, 12:0, 14:0, 15:0, and 18:1 omega7c; trace amounts (<1%) of 10:0, 18:2 and 18:0; and no cyclopropane acids. This profile was similar to the CFA profiles of Acidovorax delafieldii, Comamonas terrigena, and strains of an unclassified Centers for Disease Control group designated weak oxidizer group 1. CFA analysis, when supplemented by phenotypic characterization, is useful for the identification of L. mirabilis isolates.

Isolation of Lautropia mirabilis from oral cavities of human immunodeficiency virus-infected children

Lautropia mirabilis, a pleomorphic, motile, gram-negative coccus, has been isolated from the oral cavities of 32 of 60 (53.3%) children infected with human immunodeficiency virus (HIV) and 3 of 25 (12.0%) HIV-uninfected controls; the association of L. mirabilis isolation with HIV infection is significant (P < 0.001). All children in the study, both HIV-infected children and controls, were born to HIV-infected mothers. The presence of this bacterium was not associated with clinical disease in these children. The HIV-infected children with L. mirabilis did not differ from the HIV-infected children without L. mirabilis in immunological status, clinical status, or systemic medications. The role of HIV infection itself or concomitant factors in the establishment of L. mirabilis in the oral cavity remains to be elucidated.

Isolation of Lautropia mirabilis from sputa of a cystic fibrosis patient

An aggregate-forming coccus, isolated twice as the predominant microorganism in sputa from a cystic fibrosis patient on consecutive days, was shown to belong to the species Lautropia mirabilis on the bases of similarities of 16S rRNA gene sequences and phenotype. These isolates of L. mirabilis appear to be the first reported from a patient with cystic fibrosis and outside of Denmark.