Actinobacillus vicugnae sp. nov., isolated from alpaca (Vicugna pacos).

Ten strains of an Actinobacillus-like organism were isolated from alpaca (Vicugna pacos) in the UK over a period of 5 years, with no known epidemiological linkages. The isolates are distinct, based on both phenotype and genotype, from any previously described Actinobacillus species. Molecular analysis, based on 16S rRNA, rpoB and infB gene sequences, placed the isolates as a novel, early branching, lineage within the currently recognised Actinobacillus sensu stricto. In agreement with the results of the single-gene analysis, average nucleotide identity values, based on whole genome sequences, showed very similar identities to a number of members of the Actinobacillus sensu stricto notably Actinobacillus equuli, Actinobacillus suis and Actinobacillus ureae. At least two phenotypic characteristics differentiate the alpaca isolates from other Actinobacillus sensu stricto species, and from taxa likely falling within this group but awaiting formal species description, with Actinobacillus anseriformium and A. equulisubsp. haemolyticus being the most closely related phenotypically. The alpaca isolates can be differentiated from A. anseriformium by production of ß-galactosidase (ONPG) and acid from raffinose, and from A. equulisubsp. haemolyticus by production of acid from d-sorbitol and failure to produce acid from d-xylose. Isolates were obtained from multiple sites in alpaca including respiratory tract, alimentary tract and internal organs although further evidence is required to understand any pathogenic significance. Based on the results of characterization described here, it is proposed that the isolates constitute a novel species, Actinobacillus vicugnae sp. nov. The type strain is W1618T (LMG30745T NCTC14090T) isolated in the UK in 2012 from oesophageal ulceration in an alpaca (Vicugna pacos).

Subgingival biodiversity in subjects with uncontrolled type-2 diabetes and chronic periodontitis.

BACKGROUND AND OBJECTIVE: There is a bidirectional relationship between periodontal disease and type-2 diabetes mellitus (DM). Inflammatory mediators may negatively affect glycemic control, and increased glucose levels and resultant glycation end-products may alter the host response against bacterial infection. However, no agreement has been reached regarding the effect of DM on periodontal subgingival microbiota. Therefore, the purpose of the present study was to compare the subgingival biodiversity in deep periodontal pockets of subjects with chronic periodontitis and either uncontrolled type-2 diabetes or no diabetes using 16S rRNA gene cloning and sequencing. MATERIAL AND METHODS: Twelve subjects with uncontrolled type-2 diabetes (glycated hemoglobin > 8%) and eleven nondiabetic subjects presenting severe and generalized chronic periodontitis were selected. Subgingival biofilm from periodontal pockets > 5 mm were assessed using the 16S rRNA gene cloning and sequencing technique. RESULTS: Significant differences were observed in subgingival microbiota between diabetic and nondiabetic subjects. Diabetic subjects presented higher percentages of total clones of TM7, Aggregatibacter, Neisseria, Gemella, Eikenella, Selenomonas, Actinomyces, Capnocytophaga, Fusobacterium, Veillonella and Streptococcus genera, and lower percentages of Porphyromonas, Filifactor, Eubacterium, Synergistetes, Tannerella and Treponema genera than nondiabetic individuals (p < 0.05). Moreover, some phylotypes, such as Fusobacterium nucleatum, Veillonella parvula, V. dispar and Eikenella corrodens were detected significantly more often in diabetic subjects than in nondiabetic subjects (p < 0.05). CONCLUSION: Subjects with uncontrolled type-2 diabetes and chronic periodontitis presented significant dissimilarities in subgingival biodiversity compared with nondiabetic subjects.

Classification of avian haemolytic Actinobacillus-like organisms (Bisgaard taxon 26) associated with anseriforme birds as Actinobacillus anseriformium sp. nov.

Avian haemolytic Actinobacillus-like organisms have tentatively been named Bisgaard taxon 26. Phenotypic information has been published on 65 strains of this taxon. In the current study, 31 isolates were selected for genotypic characterization. Thirty strains had the same rpoB sequence and only one strain diverged in 1 nt. The highest rpoB similarity to members of other taxa was 89.7 % to the type strain of Actinobacillus equuli subsp. haemolyticus and the similarity to the type strain of the type species, Actinobacillus lignieresii, was 88.2 %. The lowest 16S rRNA gene sequence similarity between strains of the group was determined in previous investigations to be 99.6 % and the highest similarities of 96.4 and 96.2 % outside the group were obtained to the reference strain of Actinobacillus genomospecies 2 and to the type strain of A. equuli subsp. equuli, respectively; 95.8-95.3 % similarity was obtained with the type strain of A. lignieresii. recN gene sequence similarities within the group were from 99.5 % (strains F66(T) and F64) to 99.8 % (strains F66(T) and F67) corresponding to genome similarities of 93.9-94.6 %, which are near the upper limit for species compared with other members of the Pasteurellaceae. The highest recN similarity outside the group (83.4 %) was observed to the type strain of Actinobacillus capsulatus, whereas the similarity to the type strain of A. lignieresii was 80.9 %, corresponding to genome similarities of 57.7 and 52.0 %, respectively. All isolates meet the phenotypic characters outlined for Actinobacillus (urease-, phosphatase- and porphyrin-positive, indole-negative, acid production from fructose, sucrose, maltose and dextrin). ß-Haemolysis of bovine blood is observed and isolates may demonstrate in vitro satellitic growth, referred to as V-factor or NAD requirement. Isolates have been obtained from the upper respiratory tract of web-footed birds in which they may cause sinusitis, conjunctivitis and septicaemia. Based on the characterization reported, it is proposed that the isolates belong to a novel species, Actinobacillus anseriformium sp. nov., which includes taxon 26 and a V-factor-dependent strain. The major fatty acids of the type strain are C(16 : 1)ω7c, C(14 : 0), C(16 : 0) and C(14 : 0) 3-OH and/or iso-C(16 : 1) I, corresponding to the profile observed for the type strain of A. lignieresii. Five to 12 characters separate A. anseriformium from other taxa of Actinobacillus, with Actinobacillus ureae being most closely related; A. anseriformium can be differentiated from A. ureae based on haemolysis, ß-glucosidase, and production of acid from (-)-D-sorbitol, trehalose and glycosides. The type strain of A. anseriformium is F66(T) ( = CCUG 60324(T) = CCM 7846(T)), which was isolated from conjunctivitis in a White Pekin duck.

[Congenital skull base defect causing recurrent bacterial meningitis].

Bacterial meningitis is a life threatening disease. Most patients will experience only one episode throughout life. Children who experience bacterial meningitis more than once, require further immunologic or anatomic evaluation. We report a 9 year old child with five episodes of bacterial meningitis due to a congenital defect of the skull base. A two and a half year old boy first presented to our medical center with pneumococcal meningitis. He was treated with antibiotics and fully recovered. Two months later he presented again with a similar clinical picture. Streptococcus pneumoniae grew in cerebrospinal fluid (CSF) culture. CT scan and later MRI of the brain revealed a defect in the anterior middle fossa floor, with protrusion of brain tissue into the sphenoidal sinus. Corrective surgery was recommended but the parents refused. Three months later, a third episode of pneumococcal meningitis occurred. The child again recovered with antibiotics and this time corrective surgery was performed. Five years later, the boy presented once again with clinical signs and symptoms consistent with bacterial meningitis. CSF culture was positive, but the final identification of the bacteria was conducted by broad spectrum 16S ribosomal RNA PCR (16S rRNA PCR) which revealed a sequence of Neisseria lactamica. CT and MRI showed recurrence of the skull base defect with encephalocele in the sphenoid sinus. The parents again refused neurosurgical intervention. A year later the patient presented with bacterial meningitis. CSF culture obtained after initiation of antibiotics was negative, but actinobacillus was identified in the CSF by 16S rRNA PCR. The patient is scheduled for neurosurgical intervention. In patients with recurrent bacterial meningitis caused by organisms colonizing the oropharynx or nasopharynx, an anatomical defect should be carefully sought and surgically repaired.

Identification of mcr-1 and a novel chloramphenicol resistance gene catT on an integrative and conjugative element in an Actinobacillus strain of swine origin.

The aim of this study was to characterize a mcr-1-carrying integrative and conjugative element (ICE) in a novel Pasteurellaceae-like bacteria of swine origin. The mcr-1-positive GY-402 strain, recovered from a pig fecal sample, was subjected to whole genome sequencing with the combination of Illumina Hiseq and MinION platforms. Genome-based taxonomy revealed that strain GY-402 exhibited highest ANI value (84.89 %) to Actinobacillus succinogenes, which suggested that it represented a novel Actinobacillus species. Sequence analysis revealed that mcr-1 was clustered with eight other resistance genes in the MDR region of a novel ICE element, named ICEAsp1. Inverse PCR and mating assays showed that ICEAsp1 is active and transferrable. In addition, six circular forms mediated by four ISApl1 elements were detected with different inverse PCR sets, indicating that flexible composite transposons could be formed by pairwise combinations of multiple IS copies. Cloning experiment and phylogenetic analysis revealed that the novel Cat protein, designated CatT, belongs to type-A family and confers resistance to chloramphenicol. In conclusion, this is, to the best of our knowledge, the first report of mcr-1 gene on ICE structure and also in Pasteurellaceae bacteria. The diverse composite transposons mediated by multicopy IS elements may facilitate the dissemination of different resistance genes.

Isolation of NH4+-tolerant mutants of Actinobacillus succinogenes for succinic acid production by continuous selection.

Actinobacillus succinogenes, a typical succinic acid producing microorganism, was inhibited seriously by ammonium ion, which hampered industrialization of A. succinogenes with ammonium ion based material as the pH controller. In this study, we have isolated an ammonium ion-tolerant mutant of A. succinogenes by continuous-culture technique in which all environmental factors beside the stress (ammonium ion) were maintained constant. In this technique, the mutant-generating system was not operated as a nutrient-limited chemostat, but as a nutrient-unlimited system where cells were continuous cultured at the maximum specific growth rate. Mutants were isolated on agar plates containing a acid-base indicator bromothymol blue and high level of ammonium ion which gives 100% killing of the parent strain. When cultured in anaerobic bottles at ammonium ion concentration of 354 mmol/L, the mutant YZ0819 could produce succinic acid 40.21 g/L with yield 80.4%, while the parent strain NJ113 did not grow. With NH4OH being used to buffer the culture pH in 3.0 liter stirred bioreactor, YZ0819 produced 35.15 g/L succinic acid with yield 70.3%, 155% higher than that obtained by NJ113. In addition, the morphology of YZ0819 in fermentation broths was changed. Cells of YZ0819 were aggregated from the beginning to the end of fermentation. These results indicate that YZ0819 would be used to be the potential strain produced efficiently succinic acid with NH4OH as the pH controller and the formation of aggregates may be useful as an aid in the transferring of cells from a cultivation medium for various industrial applications.

Tracheal microbial populations in horses with moderate asthma.

BACKGROUND: There are limited data on potential dysbiosis of the airway microbiota in horses with asthma. HYPOTHESIS/OBJECTIVES: We hypothesized that the respiratory microbiota of horses with moderate asthma is altered. Our objectives were (a) to quantify tracheal bacterial populations using culture and qPCR, (2) to compare aerobic culture and qPCR, and (c) to correlate bacterial populations with bronchoalveolar lavage fluid (BALF) cytology. ANIMALS: Eighteen horses with moderate asthma from a hospital population and 10 controls. METHODS: Prospective case-control study. Aerobic culture was performed on tracheal aspirates, and streptococci, Pasteurella multocida, Chlamydophila spp., Mycoplasma spp., as well as 16S (bacterial) and 18S (fungal) rRNA subunits were quantified by qPCR. RESULTS: Potential pathogens such as Streptococcus spp., Actinobacillus spp., and Pasteurellaceae were isolated from 8, 5, and 6 horses with asthma and 3, 0, and 2 controls, respectively. There was a positive correlation between Streptococcus spp. DNA and 16S rRNA gene (r ≥ 0.7, P ≤ 0.02 in both groups), but the overall bacterial load (16S) was lower in asthma (1.5 ± 1.3 versus 2.5 ± 0.8 × 104 copy/µL, P < 0.05). There was no association between microbial populations and clinical signs, tracheal mucus or BALF inflammation. CONCLUSIONS AND CLINICAL IMPORTANCE: This study does not support that bacterial overgrowth is a common feature of chronic moderate asthma in horses. Lower bacterial load could suggest dysbiosis of the lower airways, either as a consequence of chronic inflammation or previous treatments, or as a perpetuating factor of inflammation.

Actinobacillus species isolated from Japanese Thoroughbred racehorses in the last two decades.

Actinobacillus species are known to be pathogenic to horses. To clarify etiological agents of actinobacillosis in Japanese adult horses, 27 isolates from Japanese Thoroughbred racehorses putatively identified by matrix-assisted laser desorption ionization time-of-flight mass spectrometry as Actinobacillus were further identified by PCR of the A. equuli toxin gene, by CAMP test, and by 16S rRNA sequencing analysis. Actinobacillus equuli subsp. haemolyticus was isolated most frequently (16/27) and was related to respiratory infections. Actinobacillus equuli subsp. equuli (4/27) was isolated from chronic cases or concomitant with other bacterial infections. The remainder were A. pleuropneumoniae, unclassified Actinobacillus species and Pasteurella caballi. Actinobacillus equuli including subsp. haemolyticus and subsp. equuli were the species most frequently isolated from equine actinobacillosis in Japan.

Diverse strains of Actinobacillus lignieresii isolated from clinically affected cattle in a geographically restricted area.

OBJECTIVE: To investigate whether an outbreak of Actinobacillus lignieresii was caused by one or multiple strains. METHODS: Nine isolates of A. lignieresii were obtained from the lymph nodes of 15 affected cattle from two farms to determine whether a single strain was involved. An enterobacterial repetitive insertion consensus sequence (ERIC) PCR was used for genotyping, and the repeats-in-toxin genes were analysed by PCR and sequencing. RESULTS: Isolates from the two farms belonged to two and three genotypes, with a total of four genotypes detected. Genes of the apxICABD operons of some strains had deletions in the apxIA (~697 bp) and in the apxID (~187 bp) genes. The toxin gene deletions and the ERIC PCR patterns suggested the involvement of different A. lignieresii genotypes. CONCLUSION: There was no evidence that a unique genotype was associated with actinobacillosis on the two farms, confirming that this disease was associated with other contributing factors.

Routine phenotypic identification of bacterial species of the family Pasteurellaceae isolated from animals.

Pasteurellaceae are bacteria with an important role as primary or opportunistic, mainly respiratory, pathogens in domestic and wild animals. Some species of Pasteurellaceae cause severe diseases with high economic losses in commercial animal husbandry and are of great diagnostic concern. Because of new data on the phylogeny of Pasteurellaceae, their taxonomy has recently been revised profoundly, thus requiring an improved phenotypic differentiation procedure to identify the individual species of this family. A new and simplified procedure to identify species of Actinobacillus, Avibacterium, Gallibacterium, Haemophilus, Mannheimia, Nicoletella, and Pasteurella, which are most commonly isolated from clinical samples of diseased animals in veterinary diagnostic laboratories, is presented in the current study. The identification procedure was evaluated with 40 type and reference strains and with 267 strains from routine diagnostic analysis of various animal species, including 28 different bacterial species. Type, reference, and field strains were analyzed by 16S ribosomal RNA (rrs) and rpoB gene sequencing for unambiguous species determination as a basis to evaluate the phenotypic differentiation schema. Primary phenotypic differentiation is based on beta-nicotinamide adenine dinucleotide (beta-NAD) dependence and hemolysis, which are readily determined on the isolation medium. The procedure divides the 28 species into 4 groups for which particular biochemical reactions were chosen to identify the bacterial species. The phenotypic identification procedure allowed researchers to determine the species of 240 out of 267 field strains. The procedure is an easy and cost-effective system for the rapid identification of species of the Pasteurellaceae family isolated from clinical specimens of animals.

[Screening, breeding and metabolic analysis of a succinic-acid-producing strain].

OBJECTIVE: In order to obtain high yield mutant strains for the industrial bioconversion of succinic acid, we analyzed the metabolic networks of the strain Actinobacillus succinogenes S.JST in the course of screening and breeding. METHODS: We previously identified the wild-type strain by API biochemical reactions and 16S r RNA sequence analysis. Following the discussion of the metabolic pathway, we calculated the flux by matrix and disturbed the node by intermediate. RESULTS: A succinic-acid-producing strain S.JST isolated from bovine rumen was identified as Actinobacillus succinogenes. Enzyme determination showed that the activities of phosphoenolpyruvate carboxykinase and malate dehydrogenase were very high. Metabolic flux from parent strain indicated that the flux of by-product ethanol was 1.51 mmol x g(-1) x h(-1) in the second place of those end products. After being mutated, the alcohol dehydrogenase activity of the mutant-strain S.JSTA decreased markedly, furthermore the flux of succinic acid increased by 34% and the flux of ethanol decreased by 93%. By analyzing the Adh gene, we found a mutated site. Bioinformatics showed that the corresponding amino acid sequence acted as the key active site binding with NADH. CONCLUSION: In succinic acid synthesis, directed breeding method was effective for improving the whole cell metabolism of Actinobacillus succinogenes, and succinic acid yield was increased.

Use of next generation sequencing to investigate the microbiota of experimentally induced wounds and the effect of bandaging in horses.

OBJECTIVES: To use next generation sequencing to characterize the microbiota of horses during healing of skin wounds in two anatomical locations (body and limb) known to present different healing patterns; and to investigate the impact of bandaging on bacterial communities of skin wounds located on the limbs of horses. METHODS: Full-thickness skin wounds were created on the distal extremity of both thoracic limbs and on one lateral mid-thoracic wall of four healthy horses. Limb wounds were randomly assigned to bandaging or not. A full-thickness sample was collected with a biopsy punch from intact thorax and limb skin (T0) and from the margin of one wound per site (thorax, unbandaged limb, bandaged limb) 1 week (T1) and 2 weeks (T2) postoperatively, and at full healing (T3). Thoracic skin samples obtained from three healthy horses were included in the analysis as controls. RESULTS: Anatomic location (thorax vs. limb) significantly influenced bacterial composition of equine skin and healing wounds. Fusobacterium and Actinobacillus were strongly associated with limb wounds during the initial phases of healing. Bandaging had a significant impact on the microbiota during the healing process. The skin microbiota after healing was more similar to samples from controls, demonstrating the resilience and stability of the environment. CONCLUSIONS: Equine skin microbiota is a rich and stable environment that is disturbed by wounding, but returns to its previous stage after full healing. Anatomic location significantly influences bacterial composition of the equine skin during wound healing. Bandaging has a significant impact on the skin microbiota of horses during the healing process. Results of this study provide new insight for a better understanding of the contribution of bacteria to wound healing in horses and may facilitate the future development of therapeutic strategies using commensal bacteria.

Natural lymphatic ("atypical") actinobacillosis in cattle caused by Actinobacillus lignieresii.

Bovine actinobacillosis is typically characterized by pyogranulomatous glossitis (wooden tongue). The involvement of other tissues, generally the skin or lymph nodes, has been regarded as atypical or cutaneous. We describe herein 2 outbreaks of actinobacillosis affecting primarily the lymph nodes of the head and neck. The disease affected 40 of 540 lactating cows in a dairy herd, and 5 of 335 two-y-old steers in a beef herd. Multiple or single, occasionally ulcerated nodules were observed in the region of the mandible, neck, and shoulder, including the parotid, submandibular, retropharyngeal, and prescapular lymph nodes. The histologic lesions were multifocal pyogranulomatous lymphadenitis, dermatitis, and cellulitis with Splendore-Hoeppli material. One steer had an exophytic pyogranuloma in the gingiva and another died because of ruminal tympany secondary to oropharyngeal and esophageal obstruction by a pyogranulomatous mass. Actinobacillus lignieresii was isolated from the lesions and identified by amplification, sequencing, and analysis of the 16S ribosomal (r)DNA gene. Seven of 8 cows recovered after treatment with sodium iodide. Lymphatic actinobacillosis is a frequent disease in Uruguay, southern Brazil, and Argentina. Morbidity is 1-50%; mortality is <1%. A. lignieresii apparently penetrates the intact oral and pharyngeal mucosa, infecting primarily the regional lymph nodes. Later, lesions may extend to the subcutaneous tissue and the skin, causing ulceration. Affected cattle with draining pyogranulomas contaminate the environment, favoring disease transmission, and should be treated with sodium iodide or antibiotics and isolated from the herd in order to control the disease.

Prevalence of "Actinobacillus porcitonsillarum" in porcine tonsils and development of a diagnosis duplex PCR differentiating between "Actinobacillus porcitonsillarum" and Actinobacillus pleuropneumoniae.

"Actinobacillus porcitonsillarum" is a newly suggested commensal species colonizing porcine tonsils. In the diagnostic laboratory the sole difference to the porcine lung pathogen Actinobacillus pleuropneumoniae is a negative mannitol reaction. In order to substantiate and improve this important differentiation a PCR test was developed using the relevant reference strains including Actinobacillus minor. The practicability of the test was confirmed on 20 clinical isolates of Actinobacillus spp. cultured from 100 tonsil samples originating from 18 farms in Thailand. Applying the newly developed PCR test 10 isolates were identified as A. pleuropneumoniae, and 10 as "A. porcitonsillarum" with one of them being mannitol-positive in biochemical testing. Subsequent 16S rRNA sequencing confirmed classification of all 10 strains as "A. porcitonsillarum"/A. minor. These results emphasize that suspected A. pleuropneumoniae isolates, particularly from porcine tonsils, should be confirmed by PCR in order to prevent false positive diagnoses.

Isolation of [Actinobacillus] rossii from an aborted piglet.

CASE REPORT: This report describes an investigation into the cause of abortions on a commercial pig farm in Victoria in October 2015 in which six sows aborted over a 2-month period. Four of the abortions occurred in the 3 weeks prior to the sows' anticipated farrowing dates and the other two occurred in the second trimester of pregnancy. An analysis of farm data showed that the abortion rate in the previous 12 months (2014-15) was more than twice that of the previous 2 years (1.2% vs 0.5%). Parity appeared not to be a risk factor for abortions. There were no other indicators of reproductive failure on the farm and there were no obvious clinical signs of disease in affected sows. Placenta and aborted fetuses for postmortem analysis were collected while one of the sows was aborting. The only gross abnormality detected in piglets was reddening over the skin. On gross examination the surfaces of the placentas appeared diffusely thickened and 'furry'. Histological examination of fixed placenta from one of two piglets showed a severe, acute, multifocal, necrosuppurative placentitis. Gram staining of a histological section of the placenta revealed abundant Gram-negative short bacilli, consistent with Pasteurella-Actinobacillus spp. A sample of stomach contents from one piglet yielded a profuse predominant growth of bacteria described as Pseudomonas-like. This organism was subsequently identified using 16sRNA sequencing to have 98% homology with [Actinobacillus] rossii. CONCLUSION: This is the first reported case of [A.] rossii isolated from an aborted pig's stomach in Australia.

Multifocal suppurative granuloma caused by Actinobacillus lignieresii in the peritoneum of a beef steer.

An imported crossbred Angus beef steer aged eight to twelve months died suddenly on the eighth day of a quarantine period in Japan. Gross examination showed the peritoneum and mesentery consisted of numerous nodules of various sizes. Histological examination revealed chronic suppurative granulomatous peritonitis with eosinophilic rosettes surrounding colonies of Gram-negative bacilli. The bacteria isolated from the nodules were confirmed to be Actinobacillus lignieresii based on the results of 16S rRNA gene sequencing and immunohistochemistry. Antibiotic sensitivity testing showed that the isolate was resistant to penicillin. Thus, a diagnosis of atypical actinobacillosis caused by A. lignieresii was made.

The Potential Effect of Oral Microbiota in the Prediction of Mucositis During Radiotherapy for Nasopharyngeal Carcinoma.

BACKGROUND: Oral mucositis is probably the most debilitating complication that can arise in treating a patient with head and neck cancer. Little is known about the impacts of oral microbiota on the initiation and progression of mucositis. METHODS: Based on 16S rRNA gene sequencing, dynamic changes in oral bacterial profile as well as correlations between the severity of mucositis and bacterial shifts during radiotherapy were investigated. FINDINGS: Our results revealed that bacterial community structure altered progressively during radiation therapy, in parallel with a marked increase in the relative abundance of some Gram-negative bacteria. Patients who eventually developed severe mucositis harbored a significantly lower bacterial alpha diversity and higher abundance of Actinobacillus during the phase of erythema - patchy mucositis. Accordingly, a random forest model for predicting exacerbation of mucositis was generated, which achieved a high predictive accuracy (AUC) of 0.89. INTERPRETATION: Oral microbiota changes correlate with the progression and aggravation of radiotherapy-induced mucositis in patients with nasopharyngeal carcinoma. Microbiota-based strategies can be used for the early prediction and prevention of the incidence of severe mucositis during radiotherapy.

Microbiota of the dorsum of the tongue after plaque accumulation: an experimental study in humans.

BACKGROUND: The purpose of the present investigation was to determine the effect of the absence of tongue hygiene on the microbiota of the dorsum of the tongue. METHODS: Ten volunteers (aged 19 to 22 years) entered the study at baseline and were instructed to abstain from tongue cleaning for 7 days, followed by a period of 3 days without any kind of oral hygiene. Subsequently, a period of 21 days of washout was employed, and this protocol was repeated three times. Microbiological samples were obtained from the dorsum of the tongue at baseline and at the end of the period of coating accumulation and analyzed using the checkerboard DNA-DNA hybridization technique. RESULTS: The species found in highest mean counts at baseline and day 10 were Prevotella melaninogenica and Veillonella parvula. The mean bacterial total counts enhanced significantly during the study (from 17.1x10(6) to 33.7x10(6)). Proportions of red and blue complexes and levels of 18 species also increased after the period of coating accumulation, including several periodontal pathogens, such as Prevotella intermedia, Prevotella nigrescens, Streptococcus constellatus, Tannerella forsythensis, Porphyromonas gingivalis, Treponema denticola, and P. melaninogenica. CONCLUSION: The tongue surface could be an important reservoir for periodontal pathogens and may play a role in the recolonization of tooth surfaces and in the etiology of oral halitosis.

First isolation of Actinobacillus genomospecies 2 in Japan.

We describe here the first isolation of Actinobacillus genomospecies 2 in Japan. The isolate was found in a septicemic foal and characterized by phenotypic and genetic analyses, with the latter consisting of 16S rDNA nucleotide sequence analysis plus multilocus sequence analysis using three housekeeping genes, recN, rpoA and thdF, that have been proposed for use as a genomic tool in place of DNA-DNA hybridization.

Actinobacillosis outbreak in cattle with clinical manifestation of hippopotamus-like face / Actinobacilose em bovinos com manifestação clínica de cara de hipopótamo

Actinobacillosis outbreak with clinical manifestation of hippopotamus-like face observed in a property located in the municipality of Capão do Leão, Southern Brazil, in September 2016, is described. The cattle herd remained for most of the year in rice stubble. When these areas were occupied with new crops, they were transferred to areas where there were small native forests. Three cattle were affected. They presented a volume increase in the nasolabial and maxillary region, and there was also regional lymph node swelling. The evolution of the disease occurred in approximately six months. In tissue fragments collected for culture, Actinobacillus lignieresii was isolated. The diagnosis was based on clinical findings, histopathological evaluation characterized by the presence of piogranulomas with Splendore Hoepli reaction in its center, bacterial isolation, and identification of A. lignieresii by polymerase chain reaction (PRC) and genetic sequencing.(AU)

Descreve-se um surto de actinobacilose com manifestação clínica de cara de hipopótamo diagnosticado em uma propriedade localizada no município do Capão do Leão, Rio Grande do Sul em setembro de 2016. Os bovinos permaneciam durante a maior parte do ano em restevas de arroz e quando as áreas eram ocupadas com novas lavouras eram transferidos para áreas onde havia pequenas matas nativas. Foram afetados três bovinos adultos que apresentavam aumento de volume na região nasolabial e maxilar e havia, também, tumefação dos linfonodos regionais. A evolução da enfermidade era de aproximadamente seis meses. Nos fragmentos coletados para cultura houve isolamento de Actinobacillus lignieresii. O diagnóstico foi baseado nos achados clínicos, na avaliação histopatológica caracterizada pela presença de piogranulomas com reação de Splendori Hoepli no centro, no isolamento bacteriano, identificação de Actinobacillus lignieresii por reação em cadeia da polimerase (PRC) e sequenciamento genético.(AU)