Genus Moraxella Research Articles

Pediatric asthma comprises different phenotypic clusters with unique nasal microbiotas

BackgroundPediatric asthma is the most common chronic childhood disease in the USA, currently affecting ~ 7 million children. This heterogeneous syndrome is thought to encompass various disease phenotypes of clinically observable characteristics, which can be statistically identified by applying clustering approaches to patient clinical information. Extensive evidence has shown that the airway microbiome impacts both clinical heterogeneity and pathogenesis in pediatric asthma. Yet, so far, airway microbiotas have been consistently neglected in the study of asthma phenotypes. Here, we couple extensive clinical information with 16S rRNA high-throughput sequencing to characterize the microbiota of the nasal cavity in 163 children and adolescents clustered into different asthma phenotypes.ResultsOur clustering analyses identified three statistically distinct phenotypes of pediatric asthma. Four core OTUs of the pathogenic genera Moraxella, Staphylococcus, Streptococcus, and Haemophilus were present in at least 95% of the studied nasal microbiotas. Phyla (Proteobacteria, Actinobacteria, and Bacteroidetes) and genera (Moraxella, Corynebacterium, Dolosigranulum, and Prevotella) abundances, community composition, and structure varied significantly (0.05 < P ≤ 0.0001) across asthma phenotypes and one of the clinical variables (preterm birth). Similarly, microbial networks of co-occurrence of bacterial genera revealed different bacterial associations across asthma phenotypes.ConclusionsThis study shows that children and adolescents with different clinical characteristics of asthma also show different nasal bacterial profiles, which is indicative of different phenotypes of the disease. Our work also shows how clinical and microbial information could be integrated to validate and refine asthma classification systems and develop biomarkers of disease.

Differentially Regulated Host Proteins Associated with Chronic Rhinosinusitis Are Correlated with the Sinonasal Microbiome.

The chronic inflammatory nature of chronic rhinosinusitis (CRS) makes it a morbid condition for individuals with the disease and one whose pathogenesis is poorly understood. To date, proteomic approaches have been applied successfully in a handful of CRS studies. In this study we use a multifaceted approach, including proteomics (iTRAQ labeling) and microbiome (bacterial 16S rRNA gene sequencing) analyses of middle meatus swabs, as well as immune cell analysis of the underlying tissue, to investigate the host-microbe interaction in individuals with CRS (n = 10) and healthy controls (n = 9). Of the total 606 proteins identified in this study, seven were significantly (p < 0.05) more abundant and 104 were significantly lower in the CRS cohort compared with healthy controls. The majority of detected proteins (82% of proteins identified) were not significantly correlated with disease status. Elevated levels of blood and immune cell proteins in the CRS cohort, together with significantly higher numbers of B-cells and macrophages in the underlying tissue, confirmed the inflammatory status of CRS individuals. Protein PRRC2C and Ras-related protein (RAB14) (two of the seven elevated proteins) showed the biggest fold difference between the healthy and CRS groups. Validation of the elevated levels of these two proteins in CRS samples was provided by immunohistochemistry. Members of the bacterial community in the two study cohorts were not associated with PRRC2C, however members of the genus Moraxella did correlate with RAB14 (p < 0.0001, rho = −0.95), which is a protein involved in the development of basement membrane. In addition, significant correlations between certain members of the CRS bacterial community and 33 lower abundant proteins in the CRS cohort were identified. Members of the genera Streptococcus, Haemophilus and Veillonella were strongly correlated with CRS and were significantly associated with a number of proteins with varying functions. The results from this study reveal a strong association between the host and microbes in the sinonasal cavity. Proteins identified as associated with CRS could be new targets for drug therapies and biomarkers for assessment of treatment efficacy.

Psychrobacter pasteurii and Psychrobacter piechaudii sp. nov., two novel species within the genus Psychrobacter.

Six Gram-negative, non-motile, non-spore-forming, non-pigmented, oxidase- and catalase-positive bacterial strains were deposited in 1972, in the Collection of the Institut Pasteur (CIP), Paris, France. The strains, previously identified as members of the genus Moraxella on the basis of their phenotypic and biochemical characteristics, were placed within the genus Psychrobacter based on the results from comparative 16S rRNA gene sequence studies. Their closest phylogenetic relatives were Psychrobacter sanguinis CIP 110993T, Psychrobacter phenylpyruvicus CIP 82.27T and Psychrobacter lutiphocae CIP 110018T. The DNA G+C contents were between 42.1 and 42.7 mol%. The predominant fatty acids were C18 : 1ω9c, C16 : 0, C12 : 0 3-OH, and C18 : 0. Average nucleotide identity between the six strains and their closest phylogenetic relatives, as well as their phenotypic characteristics, supported the assignment of these strains to two novel species within the genus Psychrobacter. The proposed names for these strains are Psychrobacter pasteurii sp. nov., for which the type strain is A1019T (=CIP 110853T=CECT 9184T), and Psychrobacter piechaudii sp. nov., for which the type strain is 1232T (=CIP110854T=CECT 9185T).

Auxin production by rhizobacteria was associated with improved yield of wheat (Triticum aestivum L.) under drought stress

ABSTRACTDrought tolerant rhizobacteria of the genus Bacillus, Enterobacter, Moraxella and Pseudomonas colonizing the root system of Acacia arabica were isolated to mitigate the drought stress of wheat (Triticum aestivum L.). In vitro auxin production by rhizobacteria was quantified by Ultra High Performance Liquid Chromatography (UPLC). Analysis of the crude extracts detected the indole-3-acetic acid (IAA), indole-3-carboxylic acid (ICA) and indole-3-lactic acid (ILA). Highest IAA production of 25.9 µg ml−1 was observed for Bacillus amyloliquefaciens S-134. Pot trials were conducted to evaluate the role of rhizobacteria to enhance the growth of wheat at different water regimes. At highest water stress i.e. 10% field capacity (FC), significant improvement of shoot length was observed with B. amyloliquefaciens S-134. For yield parameters, B. muralis D-5 and E. aerogenes S-10 recorded 34% and 1 fold increases for spike length and seed weight, over respective control at 10% FC. Mixed culture combinations of M-2 (B. thuringiensis S-26, D-2, B. amyloliquefaciens S-134, B. simplex D-11) and M-3 (M. pluranimalium S-29, B. simplex D-1, B. muralis D-5, P. stutzeri S-80) showed significant improvement for tillers and number of spikelets. In conclusion, application of the drought tolerant rhizobacteria can help to overcome productivity losses in drought prone areas.

Bacterial microbiota of the upper respiratory tract and childhood asthma

Patients with asthma and healthy controls differ in bacterial colonization of the respiratory tract. The upper airways have been shown to reflect colonization of the lower airways, the actual site of inflammation in asthma, which is hardly accessible in population studies. We sought to characterize the bacterial communities at 2 sites of the upper respiratory tract obtained from children from a rural area and to relate these to asthma. The microbiota of 327 throat and 68 nasal samples from school-age farm and nonfarm children were analyzed by 454-pyrosequencing of the bacterial 16S ribosomal RNA gene. Alterations in nasal microbiota but not of throat microbiota were associated with asthma. Children with asthma had lower α- and β-diversity of the nasal microbiota as compared with healthy control children. Furthermore, asthma presence was positively associated with a specific operational taxonomic unit from the genus Moraxella in children not exposed to farming, whereas in farm children Moraxella colonization was unrelated to asthma. In nonfarm children, Moraxella colonization explained the association between bacterial diversity and asthma to a large extent. Asthma was mainly associated with an altered nasal microbiota characterized by lower diversity and Moraxella abundance. Children living on farms might not be susceptible to the disadvantageous effect of Moraxella. Prospective studies may clarify whether Moraxella outgrowth is a cause or a consequence of loss in diversity.

Neonatal early onset sepsis due to Moraxella osloensis: Case-report and revision of the literature

We report the first case of early-onset systemic neonatal infection associated with Moraxella osloensis bacteriemia in a full term baby. The genus Moraxella is constituted by a group of pleomorphic bacteria obligate aerobes, Gram-negative, oxidase positive and indole negative infrequently isolated from clinical specimens. The organism is rarely reported in the literature as the causative agent of infection in humans, mostly in immunocompromised patients. Only 12 cases of M. osloensis-related infections during childhood have been reported in the literature so far. This unique report of M. osloensis infection, during the neonatal period, concerns the isolation of the bacteria in purulent secretions from the eyes of a 3-week-old baby with opthalmia. In our patient, the precocity of the onset of symptoms allows us to hypothesize a vertical transmission of the bacteria.

The subgenus names Moraxella and Branhamella (in the genus Moraxella) are not in accordance with the International Code of Nomenclature of Bacteria and are therefore not validly published: Supplementary information to Opinion 83. Judicial Commission of the International Committee on Systematics of Prokaryotes.

The publication of Opinion 83, which dealt with the valid publication of the subgenus names Moraxella and Branhamella (in the genus Moraxella), has highlighted a problem relating to the absence of descriptions associated with these names at the time they were effectively published. This calls into question whether the ruling outlined in Opinion 83, that these names should have qualified for inclusion on the Approved Lists of Bacterial Names, and their inclusion on Validation List 15 are not in accordance with Rule 27 of the International Code of Nomenclature of Bacteria governing the valid publication of a name. The subgenus names Moraxella and Branhamella (in the genus Moraxella) are not to be considered to be included on the Approved Lists of Bacterial Names, nor are they to be considered to be validly published by inclusion on Validation List 15.

Faucicola mancuniensis gen. nov., sp. nov., isolated from the human oropharynx.

An aerobic, Gram-stain-negative, non-motile coccus, designated strain GVCNT2(T), was isolated from the tonsils of a healthy adult female. Cells were oxidase- and catalase-positive, positive for the production of esterase (C4), esterase lipase (C8) and leucine arylamidase, and weakly positive for naphthol-AS-BI-phosphohydrolase and alkaline phosphatase. Cells were also capable of hydrolysing DNA. Growth was observed at 20-37 °C and in the presence of up to 1.5% NaCl. Phylogenetic analysis of near full-length 16S rRNA gene sequences indicated that the strain exhibited closest sequence similarity to Moraxella boevrei ATCC 700022(T) (94.68%) and an uncultured, unspeciated bacterial clone (strain S12-08; 99%). The major fatty acids were C18:1ω9c, C18 : 0, C16:0 and C16:1ω6c/C16:1ω7c. The DNA G+C content of strain GVCNT2(T) was 40.7 mol%. The major respiratory quinone identified was Q-8. Strain GVCNT2(T) exhibited a comparable phenotypic profile to other members of the genus Moraxella but could be distinguished based on its ability to produce acid (weakly) from d-glucose, melibiose, l-arabinose and rhamnose and on its ability to hydrolyse DNA. On the basis of phenotypic and phylogenetic differences from other members of the family Moraxellaceae, strain GVCNT2(T) is considered to represent a novel species of a new genus, for which the name Faucicola mancuniensis gen. nov., sp. nov. is proposed. The type strain of Faucicola mancuniensis is GVCNT2(T) ( =DSM 28411(T) =NCIMB 14946(T)).

AtfA, a new factor in global regulation of transcription in Acinetobacter spp

Acinetobacter species are widely distributed bacteria in the environment, and have recently gained notoriety as opportunistic nosocomial pathogens. Here we characterize a novel RNA polymerase-interacting protein named acidic transcription factor A, AtfA. It is small and highly acidic, and is widely distributed throughout the γ proteobacteria, including other significant pathogens in the genera Moraxella, Pseudomonas, Legionella and Vibrio. In the model species A. baylyi ADP1, deletion of atfA significantly affects expression of over 500 genes, resulting in a large cell phenotype, reduced cell fitness, impaired biofilm formation and twitching motility, and increased sensitivity to antibiotics. Deletion of atfA also causes dramatically enhanced sensitivity to ethanol, which is an important growth promoter and virulence factor in Acinetobacter spp. The results suggest that auxiliary factors of RNA polymerase with important biological roles remain to be discovered.

The First Korean Case of Moraxella osloensis Bacteremia in a Patient with Acute Myeloid Leukemia

The First Korean Case of Moraxella osloensis Bacteremia in a Patient with Acute Myeloid Leukemia

Diversity of Moraxella spp. strains recovered from infectious bovine keratoconjunctivitis cases in Uruguay

Infectious bovine keratoconjunctivitis (IBK) is the most common ocular disease that affects cattle throughout the world and it has a very significant economic impact. IBK is caused by members of the genus Moraxella and therapeutic and preventive measures have shown limited success. Vaccines, most of them chemically inactivated bacterins, generally induce a limited protection. In this study, the genetic diversity of Uruguayan clinical Moraxella bovis and Moraxella bovoculi isolates was assessed by RAPD-PCR, ERIC-PCR and BOX-PCR fingerprinting. Also, antibiotic resistance of the Moraxella spp. isolates was assessed utilizing the disk diffusion method. When interspecific molecular diversity was assessed, different bands patterns were observed even within a single outbreak of IBK, showing the coexistence of different genotypes of Moraxella spp. The high genetic diversity within M. bovis and M. bovoculi isolates did not permit to correlate isolates DNA fingerprints with geographical origins, dates or even with both different Moraxella species. Antibiotics resistance patterns showed significant differences between M. bovis and M. bovoculi. This is the first study of diversity that includes M. bovis and M. bovoculi associated to IBK cases. Genetic diversity did not allow to correlate DNA fingerprints of the isolates with geographical origins, isolation dates or even both different Moraxella species. Antibiotics resistance patterns showed differences between M. bovis and M. bovoculi. This remarkable variation within isolates could explain the partial protection induced by commercial vaccines. All these findings could be important for the design of prevention or treatment strategies against IBK.

Variation and Characterization of Bacterial Communities Contaminating Two Saunas Operated at 64℃ and 76℃

This study was performed to analyze 6 day-term variations in bacterial communities contaminating the floor of two dry saunas that were operated at 64℃ (low temp) and 76℃ (high temp). Bacteria were sampled daily from the saunas for 6 days from Monday to Saturday. Genomic DNA was isolated directly from bacteria-collected cotton swabs. The diversity of the bacterial communities collected from the saunas was analyzed using thermal gradient gel electrophoresis (TGGE). The total numbers of DNA bands separated by TGGE for bacteria collected from the low temp and high temp sauna were 20 and 18, respectively, during the 6 days. Seven of 20 bacteria in the low temp sauna and eight of 18 bacteria in the high temp sauna were detected more than three times over the 6 experimental days. Twelve of the 26 bacterial genera contaminating the saunas were cross detected. Bacteria belonging to the genera Moraxella and Acinetobacter were selectively detected in the low temp sauna, whereas those belonging to Aquaspirillum, Chromobacterium, Aquabacterium, Gulbenkiania, Pelomonas, and Aquitalea were selectively detected in the high temp sauna. Three species of bacteria contaminating both the low and high temp saunas were thermophile or thermoduric. The results indicate that the saunacontaminating bacteria may have been transferred from outside the saunas by user traffic but did not inhabit the saunas.

Characterization of a Moraxella species that causes epistaxis in macaques

Bacteria of the genus Moraxella have been isolated from a variety of mammalian hosts. In a prior survey of bacteria that colonize the rhesus macaque nasopharynx, performed at the Tulane National Primate Research Center, organisms of the Moraxella genus were isolated from animals with epistaxis, or “bloody nose syndrome.” They were biochemically identified as Moraxella catarrhalis, and cryopreserved. Another isolate was obtained from an epistatic cynomolgus macaque at the U.S. Army Medical Research Institute of Infectious Diseases. Based on differences in colony and cell morphologies between rhesus and human M. catarrhalis isolates, we hypothesized that the nonhuman primate Moraxella might instead be a different species. Despite morphological differences, the rhesus isolates, by several biochemical tests, were indistinguishable from M. catarrhalis. Analysis of the cynomolgus isolate by Vitek 2 Compact indicated that it belonged to a Moraxella group, but could not differentiate among species. However, sequencing of the 16S ribosomal RNA gene from four representative rhesus isolates and the cynomolgus isolate showed closest homology to Moraxella lincolnii, a human respiratory tract inhabitant, with 90.16% identity. To examine rhesus macaques as potential hosts for M. catarrhalis, eight animals were inoculated with human M. catarrhalis isolates. Only one of the animals was colonized and showed disease, whereas four of four macaques became epistatic after inoculation with the rhesus Moraxella isolate. The nasopharyngeal isolates in this study appear uniquely adapted to a macaque host and, though they share many of the phenotypic characteristics of M. catarrhalis, appear to form a genotypically distinct species.

Moraxella porci sp. nov., isolated from pigs

Nine Gram-negative, catalase- and oxidase-positive, coccus-shaped bacteria were isolated from pigs affected by different pathological processes. Phenotypic and genotypic methods were adopted to determine the relationships of these new isolates to recognized species of the genus Moraxella. Analysis of the 16S rRNA gene sequences demonstrated that the clinical isolates represented a new lineage within the genus Moraxella. The isolates were closely related to Moraxella cuniculi and Moraxella pluranimalium with 16S rRNA gene sequence similarities of 98.1 % and 99.1 %, respectively. The isolates displayed DNA-DNA relative binding ratios of 74 % to each other, but distinctly lower levels of DNA-DNA hybridization were observed with phylogenetically closely related moraxellae (<32 %). The new isolates could be distinguished from all other recognized species of the genus Moraxella by physiological and biochemical tests. On the basis of the phenotypic and molecular data, the nine new isolates from pigs represent a novel species within the genus Moraxella, for which the name Moraxella porci sp. nov. is proposed. The type strain is SN9-4M(T) (=CECT 7294(T)=CCUG 54912(T)).

Moraxella pluranimalium sp. nov., isolated from animal specimens

Four unusual Gram-negative, catalase-positive, oxidase-positive, coccus-shaped bacteria isolated from one sheep and three pigs were characterized using phenotypic and molecular genetic methods. On the basis of cellular morphology and biochemical criteria, the isolates were tentatively assigned to the genus Moraxella, although the organisms did not appear to correspond to any recognized species. Comparative 16S rRNA gene sequencing studies demonstrated that the isolates represent a novel subline within the genus Moraxella. The most closely related species in phylogenetic terms was Moraxella cuniculi, with 16S rRNA gene sequence similarity of 97.9 % to the type strain CCUG 2154(T), although the DNA-DNA relatedness value was only 29 %. The novel isolates were readily distinguished from all recognized Moraxella species by means of physiological and biochemical tests. On the basis of molecular genetic and phenotypic evidence, therefore, the four isolates represent a novel species of the genus Moraxella, for which the name Moraxella pluranimalium sp. nov. is proposed. The type strain is 248-01(T) (=CECT 7295(T) =CCUG 54913(T)).

Challenging Opinion 83

The Judicial Commission has ruled that subgenus names within the genus Moraxella should be considered to have been included on the Approved Lists, together with the corresponding species names within these subgenera. Closer examination of the facts, including the wording of the relevant passages in the Code and the original publication in which these names are included, together with information that has subsequently come to light, indicates that there is good cause to re-examine the facts on which this Opinion is based.

Fluctuation in recoverable nickel and zinc resistant copiotrophic bacteria explained by the varying zinc ion content of Torsa River in different months

Heavy metal content analysis of River Torsa in India did not indicate any alarming level of toxicity for human consumption but revealed variation at the ppb level in different months. The variation in recoverable nickel and zinc resistant copiotrophic (or eutrophic) bacterial counts was explained by the variation of the zinc content (34.0-691.3 ppb) of the river water in different sampling months. Growth studies conducted with some purified nickel and/or zinc resistant strains revealed that pre-exposure of the cells to ppb levels of Zn(2+), comparable to the indigenous zinc ion concentration of the river, could induce the nickel or zinc resistance. A minimum concentration of 5-10 microM Zn(2+ )(325-650 ppb) was found effective in inducing the Nickel resistance of the isolates. Zinc resistance of the isolates was tested by pre-exposing the cells to 4 microM Zn(2+ )(260 ppb). The lag phase was reduced by 6-8 h in all the cases. Biochemical characteristics and phylogenetic analysis based on 16S rDNA sequence indicated that some of the Torsa River isolates, having inducible nickel and zinc resistance, are members of the genus Pseudomonas, Acinetobacter, Bacillus, Enterobacter, Serratia and Moraxella.

Moraxella bovoculi sp. nov., isolated from calves with infectious bovine keratoconjunctivitis

Eighteen isolates of a Gram-negative coccus (strain 237(T)) were cultured from the eyes of dairy and beef calves affected with infectious bovine keratoconjunctivitis (IBK; 'pinkeye') in northern California, USA, during summer 2002. These isolates had near full-length (1397 bp) 16S rRNA gene sequences that clustered into three groups with 99.9 % sequence similarity. On the basis of 16S rRNA gene sequence, the isolates were most closely associated with Moraxella bovis and Moraxella ovis in clade I of the classical moraxellae. Biochemically, the novel isolates could be distinguished from the other members of the genus Moraxella isolated from animals on the basis of phenylalanine deaminase activity. The results of partial sequence analysis of six housekeeping genes, the 16S-23S rRNA gene interspacer region and partial 23S rRNA gene provide strong support for the inclusion of these isolates in a novel taxon, for which the name Moraxella bovoculi sp. nov. is proposed. The type strain is strain 237(T) (=ATCC BAA-1259(T)=CCUG 52049(T)).

Transfer of the misnamed [Alysiella] sp. IAM 14971 (=ATCC 29468) to the genus Moraxella as Moraxella oblonga sp. nov.

Phylogenetic analysis based on 16S rRNA gene sequences revealed that [Alysiella] sp. IAM 14971 (=ATCC 29468) is closely related to the genus Moraxella of the gamma-Proteobacteria (96-97 % similarity). The newly obtained phenotypic data also indicate that [Alysiella] sp. IAM 14971 is distinct from the genus Alysiella and similar to the genus Moraxella. On the basis of these results, the strain should be classified in the genus Moraxella, as Moraxella oblonga sp. nov. The type strain is IAM 14971T (=ATCC 29468T).

Bacteriological Studies on Fishes Affected with Epizootic Ulcerative Syndrome

Epizootic ulcerative syndrome is one of the most well known fish diseases that has caused disastrous effects throughout India after its first outbreak in 1988. Since then recurrences in varying intensities are reported every year. Bacteriological examination of the ulcerated area of affected C. punctatus, Puntius sp. and Mystus sp. revealed the presence of 16 strains of bacteria belonging to the genus Pseudomonas, Aeromonas, Micrococcus, Bacillus, Vibrio and Moraxella among which Pseudomonas and Aeromonas were the most common. Pathogenicity tests with all the isolates showed that only six strains belonging to the genus Aeromonas and Pseudomonas were pathogenic while the rest were nonpathogenic. The distinct inconsistency in the type of pathogenic bacteria isolated from the three fish species suggests that these are opportunistic pathogens that have invaded the fish secondarily.