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2.
Nat Med ; 2024 May 30.
Article in English | MEDLINE | ID: mdl-38816609

ABSTRACT

Accurately predicting functional outcomes for unresponsive patients with acute brain injury is a medical, scientific and ethical challenge. This prospective study assesses how a multimodal approach combining various numbers of behavioral, neuroimaging and electrophysiological markers affects the performance of outcome predictions. We analyzed data from 349 patients admitted to a tertiary neurointensive care unit between 2009 and 2021, categorizing prognoses as good, uncertain or poor, and compared these predictions with observed outcomes using the Glasgow Outcome Scale-Extended (GOS-E, levels ranging from 1 to 8, with higher levels indicating better outcomes). After excluding cases with life-sustaining therapy withdrawal to mitigate the self-fulfilling prophecy bias, our findings reveal that a good prognosis, compared with a poor or uncertain one, is associated with better one-year functional outcomes (common odds ratio (95% CI) for higher GOS-E: OR = 14.57 (5.70-40.32), P < 0.001; and 2.9 (1.56-5.45), P < 0.001, respectively). Moreover, increasing the number of assessment modalities decreased uncertainty (OR = 0.35 (0.21-0.59), P < 0.001) and improved prognostic accuracy (OR = 2.72 (1.18-6.47), P = 0.011). Our results underscore the value of multimodal assessment in refining neuroprognostic precision, thereby offering a robust foundation for clinical decision-making processes for acutely brain-injured patients. ClinicalTrials.gov registration: NCT04534777 .

4.
Rev Neurol (Paris) ; 178(1-2): 93-104, 2022.
Article in English | MEDLINE | ID: mdl-34996631

ABSTRACT

Toxic-metabolic encephalopathy (TME) results from an acute cerebral dysfunction due to different metabolic disturbances including medications or illicit-drugs. It can lead to altered consciousness, going from delirium to coma, which may require intensive care and invasive mechanical ventilation. Even if it is a life-threatening condition, TME might have an excellent prognosis if its etiology is rapidly identified and treated adequately. This review summarizes the main etiologies, their differential diagnosis, and diagnostic strategy and management of TME with a critical discussion on the definition of TME.


Subject(s)
Brain Diseases, Metabolic , Brain Diseases , Brain Diseases/diagnosis , Brain Diseases/etiology , Brain Diseases, Metabolic/diagnosis , Brain Diseases, Metabolic/etiology , Coma/diagnosis , Coma/etiology , Critical Care , Humans , Intensive Care Units , Respiration, Artificial
5.
Appl Opt ; 60(19): D52-D72, 2021 Jul 01.
Article in English | MEDLINE | ID: mdl-34263828

ABSTRACT

Over the last decade, the vector-apodizing phase plate (vAPP) coronagraph has been developed from concept to on-sky application in many high-contrast imaging systems on 8 m class telescopes. The vAPP is a geometric-phase patterned coronagraph that is inherently broadband, and its manufacturing is enabled only by direct-write technology for liquid-crystal patterns. The vAPP generates two coronagraphic point spread functions (PSFs) that cancel starlight on opposite sides of the PSF and have opposite circular polarization states. The efficiency, that is, the amount of light in these PSFs, depends on the retardance offset from a half-wave of the liquid-crystal retarder. Using different liquid-crystal recipes to tune the retardance, different vAPPs operate with high efficiencies (${\gt}96\%$) in the visible and thermal infrared (0.55 µm to 5 µm). Since 2015, seven vAPPs have been installed in a total of six different instruments, including Magellan/MagAO, Magellan/MagAO-X, Subaru/SCExAO, and LBT/LMIRcam. Using two integral field spectrographs installed on the latter two instruments, these vAPPs can provide low-resolution spectra (${\rm{R}} \sim 30$) between 1 µm and 5 µm. We review the design process, development, commissioning, on-sky performance, and first scientific results of all commissioned vAPPs. We report on the lessons learned and conclude with perspectives for future developments and applications.

6.
Ann Intensive Care ; 10(1): 62, 2020 May 24.
Article in English | MEDLINE | ID: mdl-32449053

ABSTRACT

BACKGROUND: No recommendation exists about the timing and setting for tracheal intubation and mechanical ventilation in septic shock. PATIENTS AND METHODS: This prospective multicenter observational study was conducted in 30 ICUs in France and Spain. All consecutive patients presenting with septic shock were eligible. The use of tracheal intubation was described across the participating ICUs. A multivariate analysis was performed to identify parameters associated with early intubation (before H8 following vasopressor onset). RESULTS: Eight hundred and fifty-nine patients were enrolled. Two hundred and nine patients were intubated early (24%, range 4.5-47%), across the 18 centers with at least 20 patients included. The cumulative intubation rate during the ICU stay was 324/859 (38%, range 14-65%). In the multivariate analysis, seven parameters were significantly associated with early intubation and ranked as follows by decreasing weight: Glasgow score, center effect, use of accessory respiratory muscles, lactate level, vasopressor dose, pH and inability to clear tracheal secretions. Global R-square of the model was only 60% indicating that 40% of the variability of the intubation process was related to other parameters than those entered in this analysis. CONCLUSION: Neurological, respiratory and hemodynamic parameters only partially explained the use of tracheal intubation in septic shock patients. Center effect was important. Finally, a vast part of the variability of intubation remained unexplained by patient characteristics. Trial registration Clinical trials NCT02780466, registered on May 23, 2016. https://clinicaltrials.gov/ct2/show/NCT02780466?term=intubatic&draw=2&rank=1.

7.
Rev Med Interne ; 40(2): 88-97, 2019 Feb.
Article in French | MEDLINE | ID: mdl-30638703

ABSTRACT

Metabolic encephalopathies (ME) are a common cause of admission to emergency rooms, to hospitalization wards or to intensive care units. They could account for 10 to 20% of causes of comatose states in ICU and could be associated to a poor outcome especially in older patients. Nevertheless, they are often reversible and are associated with a favorable outcome when diagnosed and rapidly treated. They correspond to an altered brain functioning secondary to the deficiency of a substance that is mandatory for the normal brain functioning or to the accumulation of a substance that can be either endogenous or exogenous. It preferably occurs in co-morbid patients, complicating its diagnosis and its management. Altered brain functioning, going from mild neuropsychological impairment to coma, movement disorders especially myoclonus and the absence of any obvious differential diagnosis are highly suggestive of the diagnosis. Whereas some biological samplings and brain MRI are essential to rule out differential diagnosis, some others, such as electroencephalogram, may be able to propose important clues in favor of the diagnosis. Once simple symptomatic measures are introduced, the treatment consists mainly in the correction of the cause. Specific treatment options are only seldom available for ME; this is the case for hepatic encephalopathy and some drug-induced encephalopathies. We will successively describe in this review the main pathophysiological mechanisms, the main causes, favoring circumstances of ME, the differential diagnosis to rule out and the etiological work-up for the diagnosis. Finally, a diagnostic and therapeutic strategy for the care of patients with ME will be proposed.


Subject(s)
Brain Diseases, Metabolic , Blood-Brain Barrier/metabolism , Blood-Brain Barrier/physiology , Brain/diagnostic imaging , Brain/metabolism , Brain/physiopathology , Brain Diseases, Metabolic/diagnosis , Brain Diseases, Metabolic/epidemiology , Brain Diseases, Metabolic/etiology , Diagnosis, Differential , Diagnostic Techniques, Neurological , Drug-Related Side Effects and Adverse Reactions/diagnosis , Drug-Related Side Effects and Adverse Reactions/epidemiology , Hepatic Encephalopathy/diagnosis , Hepatic Encephalopathy/epidemiology , Humans , Neurotoxicity Syndromes/diagnosis , Neurotoxicity Syndromes/epidemiology , Neurotoxicity Syndromes/etiology
8.
Science ; 350(6256): 64-7, 2015 Oct 02.
Article in English | MEDLINE | ID: mdl-26272904

ABSTRACT

Directly detecting thermal emission from young extrasolar planets allows measurement of their atmospheric compositions and luminosities, which are influenced by their formation mechanisms. Using the Gemini Planet Imager, we discovered a planet orbiting the ~20-million-year-old star 51 Eridani at a projected separation of 13 astronomical units. Near-infrared observations show a spectrum with strong methane and water-vapor absorption. Modeling of the spectra and photometry yields a luminosity (normalized by the luminosity of the Sun) of 1.6 to 4.0 × 10(-6) and an effective temperature of 600 to 750 kelvin. For this age and luminosity, "hot-start" formation models indicate a mass twice that of Jupiter. This planet also has a sufficiently low luminosity to be consistent with the "cold-start" core-accretion process that may have formed Jupiter.

9.
Res Vet Sci ; 93(2): 627-30, 2012 Oct.
Article in English | MEDLINE | ID: mdl-22133708

ABSTRACT

Relationships between macroscopic lesions and Polymerase Chain Reaction (PCR) detection of Mycoplasma hyopneumoniae (Mhp), Pasteurella multocida (Pm), Actinobacillus pleuropneumoniae (App), Haemophilus parasuis (Hps) and Streptococcus suis (Ssuis) of the lungs of 3731 slaughter pigs from 125 herds were assessed in France. Pneumonia and pleuritis were the most frequent lesions (69.3% and 15% of the lungs, respectively). Mhp, Pm, App, Ssuis and Hps were detected in 69.3%, 36.9%, 20.7%, 6.4% and 0.99% of the lungs, respectively. Mhp and Pm were associated with pneumonia at both the pig and herd levels. Pleuritis was not associated with any pathogen at the pig level, but was associated with a high percentage of pigs PCR-positive for App at the herd level. Measures focused on control of Mhp, Pm and App should significantly reduce the occurrence of both pneumonia and pleuritis.


Subject(s)
Bacteria/classification , Lung Diseases/microbiology , Lung Diseases/pathology , Swine Diseases/microbiology , Abattoirs , Animals , Bacteria/isolation & purification , France/epidemiology , Lung Diseases/epidemiology , Swine , Swine Diseases/epidemiology , Swine Diseases/pathology
10.
Vet Microbiol ; 147(3-4): 329-39, 2011 Jan 27.
Article in English | MEDLINE | ID: mdl-20696539

ABSTRACT

A longitudinal study was carried out in five French farrow-to-finish herds differently affected by respiratory diseases to describe the carrying and infection patterns of batches of sows to various respiratory pathogens during gestation and lactation. An entire batch of sows was followed during two successive reproduction cycles. Nasal, tonsillar and oro-pharyngeal swabs and blood samples were taken from each sow 9 and 4 weeks before farrowing and 1 and 4 weeks after farrowing. Mycoplasma hyopneumoniae, Actinobacillus pleuropneumoniae, Pasteurella multocida, Haemophilus parasuis and Streptococcus suis were detected from swab samples using PCR assays. Blood samples were tested for antibodies against M. hyopneumoniae, A. pleuropneumoniae serotypes 1-9-11 and 2, Porcine Circovirus type-2 (PCV-2) and Porcine Reproductive and Respiratory Syndrome virus (PRRSV) by ELISA tests. Antibodies against H(1)N(1), H(1)N(2) and H(3)N(2) Swine Influenza Viruses (SIV) of European lineages were tested by hemagglutination inhibition assay. The results indicated that S. suis is widespread among sows (67.1% of PCR-positive sows). A. pleuropneumoniae, P. multocida, and H. parasuis were detected by PCR in 30.9%, 24.6% and 23.4% of the sows, respectively. Antibodies against M. hyopneumoniae were recovered from more than 55% of the sows in all herds whereas the micro-organism was detected in 2.4% of the sows. Although PCV-2 and SIV infections were highly prevalent, the PRRSV infection patterns ranged from no infection in farms mildly affected by respiratory diseases to active circulation in more severely affected herds. The sow population thus constitutes a reservoir for a continuous circulation of respiratory pathogens and needs to be properly considered in control strategies.


Subject(s)
Bacterial Infections/veterinary , Respiratory Tract Infections/veterinary , Swine Diseases/epidemiology , Virus Diseases/veterinary , Animals , Antibodies, Bacterial/blood , Antibodies, Viral/blood , Bacteria/genetics , Bacteria/isolation & purification , Bacterial Infections/epidemiology , Bacterial Infections/transmission , Breeding , Enzyme-Linked Immunosorbent Assay/veterinary , Female , Hemagglutination Inhibition Tests/veterinary , Longitudinal Studies , Pregnancy , Prevalence , Respiratory Tract Infections/epidemiology , Respiratory Tract Infections/transmission , Swine , Swine Diseases/transmission , Time Factors , Virus Diseases/epidemiology , Virus Diseases/transmission
11.
Vet Microbiol ; 143(2-4): 238-45, 2010 Jul 14.
Article in English | MEDLINE | ID: mdl-20036079

ABSTRACT

Four sampling techniques for Mycoplasma hyopneumoniae detection, namely nasal swabbing, oral-pharyngeal brushing, tracheo-bronchial swabbing and tracheo-bronchial washing, were compared in naturally infected live pigs. In addition, a quantitative real-time PCR assay for M. hyopneumoniae quantification was validated with the same samples. 60 finishing pigs were randomly selected from a batch of contemporary pigs on a farm chronically affected by respiratory disorders. Each pig was submitted to nasal swabbing, oral-pharyngeal brushing, tracheo-bronchial swabbing and tracheo-bronchial washing. Nested-PCR and real-time PCR assays were performed on all samples. A Bayesian approach was used to analyze the nested-PCR results of the four sampling methods (i.e. positive or negative) to estimate the sensitivity and specificity of each method. M. hyopneumoniae was detected by nested-PCR in at least one sample from 70% of the pigs. The most sensitive sampling methods for detecting M. hyopneumoniae in live naturally infected pigs were tracheo-bronchial swabbing and tracheo-bronchial washing, as compared to oral-pharyngeal brushing and nasal swabbing. Swabbing the nasal cavities appeared to be the least sensitive method. Significantly higher amounts of M. hyopneumoniae DNA were found at the sites of tracheo-bronchial sampling than in the nasal cavities or at the oral-pharyngeal site (p<0.001). There was no difference between the tracheo-bronchial washing and the tracheo-bronchial swabbing results (p>0.05). Our study indicated that tracheo-bronchial swabbing associated with real-time PCR could be an accurate diagnostic tool for assessing infection dynamics in pig herds.


Subject(s)
Bacteriological Techniques/veterinary , Mycoplasma hyopneumoniae/isolation & purification , Pneumonia of Swine, Mycoplasmal/diagnosis , Animals , Bacterial Vaccines/immunology , Bacteriological Techniques/methods , Bayes Theorem , Pneumonia of Swine, Mycoplasmal/microbiology , Pneumonia of Swine, Mycoplasmal/prevention & control , Polymerase Chain Reaction/methods , Polymerase Chain Reaction/veterinary , Sensitivity and Specificity , Swine
12.
J Appl Microbiol ; 108(5): 1523-33, 2010 May.
Article in English | MEDLINE | ID: mdl-19811567

ABSTRACT

AIMS: A triplex real-time PCR assay to quantify Mycoplasma hyopneumoniae in specimens from live and dead pigs was developed and validated. The minimal dose of Myc. hyopneumoniae required to induce pneumonia in specific pathogen-free pigs was determined. METHODS AND RESULTS: This TaqMan test simultaneously detected three genes encoding the proteins P46, P97 and P102. All Myc. hyopneumoniae strains analysed were detected, including strains isolated in three countries (France, England and Switzerland) and from several pig farms (n = 33), and the test was specific. The estimated detection thresholds were 1.3 genome equivalents (microl(-1)) for the targets defined in p97 and p102 genes and 13 genome equivalents (microl(-1)) for the segment defined in the p46 gene. This test was used to quantify Myc. hyopneumoniae in specimens sampled from experimentally infected pigs. In live pigs, c. 10(7), 10(8) and 10(10) genome equivalents (ml(-1)) of Myc. hyopneumoniae were detected in the nasal cavities, tonsils and trachea samples, respectively. In dead pigs, 10(8)-10(10) genome equivalents (ml(-1)) of Myc. hyopneumoniae were detected in the lung tissue with pneumonia. The estimated minimal dose of Myc. hyopneumoniae required to induce pneumonia was 10(5) colour-changing units (CCU) per pig (corresponding to 10(8) mycoplasmas). CONCLUSION: The triplex RT-PCR test was validated and can be used for testing samples taken on the pig farms. SIGNIFICANCE AND IMPACT OF THE STUDY: This test should be a very useful tool in pig herds to control enzootic pneumonia or healthy carrier pigs and to study the dynamics of Myc. hyopneumoniae infections.


Subject(s)
Mycoplasma hyopneumoniae/genetics , Pneumonia of Swine, Mycoplasmal/diagnosis , Pneumonia of Swine, Mycoplasmal/microbiology , Polymerase Chain Reaction/veterinary , Animals , Antibodies, Bacterial/blood , Bacterial Load , Bacterial Proteins/genetics , Mycoplasma hyopneumoniae/isolation & purification , Pneumonia of Swine, Mycoplasmal/pathology , Polymerase Chain Reaction/methods , Random Allocation , Sensitivity and Specificity , Specific Pathogen-Free Organisms , Swine
13.
J Appl Microbiol ; 107(6): 1830-6, 2009 Dec 01.
Article in English | MEDLINE | ID: mdl-19457034

ABSTRACT

AIMS: To examine the variability among Pasteurella multocida strains isolated from pigs (nasal, tonsil and lung specimens) and humans in France. METHODS AND RESULTS: The genetic diversity of 117 French isolates of P. multocida, obtained from pigs (n = 101) and humans (n = 16) and three reference strains, was evaluated by pulsed-field gel electrophoresis (PFGE) after macrorestriction with ApaI. Sixty-four patterns were detected. The genetic relationships revealed five clusters (Aa1, Aa2, Aa3, Ab and B). The pig isolates obtained from pneumonic lungs and nasal cavities were clustered in groups Ab and Aa1, respectively (P < 0.05). Up to four different PFGE patterns were detected in the same farm. Isolates producing dermonecrotic toxins were clustered only in group Aa1, suggesting that the toxigenic isolates were more genetically homogenous than the others. Conversely, cluster Aa3 was significantly associated with human isolates even if the human isolates are spread over most of the clusters. CONCLUSIONS: Pasteurella multocida strains were genetically diverse, but pig and human isolates were significantly clustered in distinct phylogenetic groups. SIGNIFICANCE AND IMPACT OF THE STUDY: The discrimination index was >0.95 in both populations of human and pig isolates. Therefore, ApaI-PFGE seems to be a useful tool for epidemiological tracing of P. multocida infections.


Subject(s)
Pasteurella Infections/microbiology , Pasteurella Infections/veterinary , Pasteurella multocida/classification , Pasteurella multocida/isolation & purification , Swine Diseases/microbiology , Animals , Electrophoresis, Gel, Pulsed-Field , France , Genetic Variation , Humans , Pasteurella multocida/genetics , Sus scrofa
14.
Vet Microbiol ; 120(1-2): 96-104, 2007 Feb 25.
Article in English | MEDLINE | ID: mdl-17116374

ABSTRACT

The purpose of this study was to determine the optimal route of infection and the optimal sampling sites for the recovery of M. hyopneumoniae, the etiological agent of enzootic porcine pneumonia. Virulence of two strains, BQ 14 and 116, isolated in France in 1975 and 2003, respectively, was also compared. Groups of specific pathogen free piglets were experimentally infected by the intratracheal or intranasal route. One non-inoculated pig was placed in each group of infected pigs to study direct transmission. Two groups were kept uninfected. Coughing was recorded daily. Blood samples, nasal, tonsillar and tracheal swabs and tracheobronchiolar washings were collected weekly. Pigs were killed 27-37 days post-infection. Lung lesions were scored and swabs were collected from nasal cavities, tonsils, trachea, lung, liver and spleen. All the samples, collected from live and dead pigs, were cultured for M. hyopneumoniae recovery. Results showed that both experimentally infected pigs and contact pigs developed enzootic pneumonia, whatever the route of infection and the strain tested. Direct contact transmission occurred quickly. No difference between the two routes of infection or between the two strains tested was evidenced, but high individual variations were observed between pigs. Tracheal swabs and tracheobronchiolar washings were the most effective samples to detect M. hyopneumoniae compared to nasal or tonsillar swabs. Our results also suggested that tracheobronchiolar washings could have an influence on the lesion extent observed at necropsy. M. hyopneumoniae could be re-isolated from liver and spleen of experimentally infected pigs and contact pigs.


Subject(s)
Mycoplasma hyopneumoniae/isolation & purification , Pneumonia of Swine, Mycoplasmal/microbiology , Animals , Antibodies, Bacterial/blood , Enzyme-Linked Immunosorbent Assay/veterinary , Mycoplasma hyopneumoniae/growth & development , Pneumonia of Swine, Mycoplasmal/immunology , Pneumonia of Swine, Mycoplasmal/pathology , Pneumonia of Swine, Mycoplasmal/transmission , Specific Pathogen-Free Organisms , Swine
15.
J Clin Microbiol ; 42(7): 3169-75, 2004 Jul.
Article in English | MEDLINE | ID: mdl-15243078

ABSTRACT

A PCR assay was developed for the detection of Streptococcus suis serotypes 2 and 1/2. This multiplex PCR is based on the amplification of the gene coding for 16S rRNA of S. suis and on the amplification of the cps2J gene coding for the capsule of S. suis serotypes 2 and 1/2. An internal control was constructed and added in this test to monitor the efficiency of amplification in each reaction. To evaluate the specificity of the test, 31 strains of other bacterial species related to S. suis or isolated from pigs and 42 strains of S. suis serotypes 1 and 3 to 34 were analyzed. The detection threshold of the test was 28 S. suis CFU/ml. The specificity and the sensitivity of the multiplex PCR test and the presence of an internal control allowed the analysis of biological samples without a culture step. The PCR assay was then applied to the detection of 14 S. suis serotype 1/2 strains, 88 S. suis serotype 2 strains isolated from pigs, and 25 S. suis serotype 2 strains isolated from humans. This test was also applied to analyze tonsil samples of pigs experimentally infected and carrier pigs without any symptoms.


Subject(s)
Palatine Tonsil/microbiology , Polymerase Chain Reaction/methods , Streptococcus suis/isolation & purification , Swine/microbiology , Animals , Enzyme-Linked Immunosorbent Assay , Sensitivity and Specificity , Serotyping , Streptococcus suis/classification
16.
Vet Microbiol ; 89(1): 17-28, 2002 Oct 02.
Article in English | MEDLINE | ID: mdl-12223159

ABSTRACT

In order to study horizontal transmission of Mycoplasma synoviae an avian pathogen, a reverse transcription-polymerase chain reaction (RT-PCR) assay was developed to detect viable Mycoplasma in environment. The test was based on the RT-PCR of the 16S ribosomal RNA (rRNA) of Mycoplasma genus. Results showed that Mycoplasma 16S rRNA was stable up to 23 h after cell death. Therefore, the test allowed detection of viable or very recently (less than 23 h) dead mycoplasmas. M. synoviae survival in artificially contaminated water, food and soil and in the environment of M. synoviae experimentally infected turkeys was estimated by culture and RT-PCR. The RT-PCR method was then applied in a naturally infected laying hen farm showing problems of recurrent mycoplasmosis in the hens. Results confirmed the usefulness of RT-PCR in checking the efficiency of biosecurity measures and in improving cleaning and disinfection protocols.


Subject(s)
Chickens , Disease Transmission, Infectious/veterinary , Mycoplasma Infections/veterinary , Mycoplasma/isolation & purification , Poultry Diseases/microbiology , Reverse Transcriptase Polymerase Chain Reaction/veterinary , Turkeys , Air Microbiology , Animals , Female , Mycoplasma/genetics , Mycoplasma Infections/microbiology , Mycoplasma Infections/transmission , Poultry Diseases/transmission , RNA, Bacterial/chemistry , RNA, Bacterial/genetics , RNA, Ribosomal, 16S/chemistry , RNA, Ribosomal, 16S/genetics , Reverse Transcriptase Polymerase Chain Reaction/methods , Soil Microbiology , Water Microbiology
17.
Vet Microbiol ; 79(1): 1-9, 2001 Mar 02.
Article in English | MEDLINE | ID: mdl-11230924

ABSTRACT

Pulsed-field gel electrophoresis (PFGE) analysis was developed and compared with random amplified polymorphic DNA (RAPD) method to type 18 Mycoplasma synoviae (MS) strains. All analysed strains were typeable by RAPD but only 89% of MS strains were typeable by PFGE because of DNA degradation. The discriminatory power of RAPD was greater than that of PFGE but the two techniques had a discriminatory index superior to 0.95, the threshold value for interpreting typing results with confidence. The in vitro, in ovo and in vivo reproducibility of both typing techniques was 100%. However, the interpretation of RAPD patterns was complicated because of inconsistent band intensity. Thus, these molecular typing techniques should be helpful for epidemiological studies of avian mycoplasma infections.


Subject(s)
Bacterial Typing Techniques/veterinary , Electrophoresis, Gel, Pulsed-Field/veterinary , Mycoplasma Infections/veterinary , Mycoplasma/classification , Poultry Diseases/microbiology , Random Amplified Polymorphic DNA Technique/veterinary , Animals , Chickens , Disease Outbreaks/veterinary , Genotype , Mycoplasma/genetics , Mycoplasma Infections/microbiology
18.
J Vet Med B Infect Dis Vet Public Health ; 48(9): 695-703, 2001 Nov.
Article in English | MEDLINE | ID: mdl-11765805

ABSTRACT

Pulsed-field gel electrophoresis (PFGE) and random amplified polymorphic DNA (RAPD) analysis were used to compare 21 Mycoplasma gallisepticum strains and five M. imitans strains. Each strain of M. gallisepticum typed by PFGE and RAPD methods was genetically quite unique and RAPD and PFGE fingerprinting enabled strain characterization. Relationships between the M. gallisepticum and M. imitans strains were established and dendrograms were drawn from PFGE and RAPD patterns. PFGE group A and RAPD group D were significantly associated with M. imitans strains (P < 0.05). Three M. imitans strains shared the same PFGE and RAPD patterns. The two M. gallisepticum vaccine strains had singular PFGE and RAPD patterns. Thus, PFGE and RAPD can be used to investigate disease outbreaks in vaccinated flocks or for epidemiological tracking. For M. gallisepticum, the RAPD and PFGE discriminatory powers were superior to 0.95 and the in vitro, in ovo and in vivo reproducibility of RAPD and PFGE was 100%. The RAPD drawback was the inconsistent band intensity complicating the interpretation of patterns, while the PFGE limit was its low typeability (86%). Thus, these two molecular typing methods seemed complementary for M. gallisepticum epidemiological studies.


Subject(s)
Electrophoresis, Gel, Pulsed-Field/veterinary , Mycoplasma Infections/veterinary , Mycoplasma/classification , Poultry Diseases/microbiology , Random Amplified Polymorphic DNA Technique/veterinary , Animals , Chickens , Electrophoresis, Gel, Pulsed-Field/methods , Genetic Variation , Mycoplasma/genetics , Mycoplasma Infections/epidemiology , Mycoplasma Infections/microbiology , Poultry Diseases/epidemiology , Random Amplified Polymorphic DNA Technique/methods , Reproducibility of Results , Turkeys
19.
Vet Microbiol ; 73(4): 311-8, 2000 May 11.
Article in English | MEDLINE | ID: mdl-10781729

ABSTRACT

Successful detection of Mycoplasma synoviae (MS) by culture and PCR from samples collected in the environment of experimentally infected chickens and turkeys, or under field conditions, is described. Results showed that in the experimental infection, 10/96 and 46/96 samples of food, drinking water, feathers, droppings or dust were positive by culture and Mycoplasma-PCR. In field conditions, the number of positive results for environmental samples were respectively 7/28 and 17/28. These observations highlight the high disseminating capacities of this mycoplasma and show the usefulness of the PCR method for epidemiological studies.


Subject(s)
Chickens/microbiology , Mycoplasma Infections/veterinary , Mycoplasma/isolation & purification , Poultry Diseases/microbiology , Turkeys/microbiology , Animals , DNA Primers/chemistry , DNA, Bacterial/chemistry , DNA, Bacterial/isolation & purification , Dust , Electrophoresis, Agar Gel/veterinary , Feathers/microbiology , Feces/microbiology , Food Microbiology , Mycoplasma/chemistry , Mycoplasma/genetics , Mycoplasma Infections/microbiology , Mycoplasma Infections/transmission , Polymerase Chain Reaction/veterinary , Poultry Diseases/transmission , Specific Pathogen-Free Organisms , Trachea/microbiology , Water Microbiology
20.
J Clin Microbiol ; 37(6): 1892-8, 1999 Jun.
Article in English | MEDLINE | ID: mdl-10325343

ABSTRACT

A collection of 114 independent Streptococcus agalactiae strains, including 54 strains isolated from the cerebrospinal fluid (CSF) samples of neonates and 60 strains from asymptomatic patients, was characterized by pulsed-field gel electrophoresis (PFGE) of DNA restricted with SmaI and by PCR analysis of the hylB gene. All strains were previously studied by multilocus enzyme electrophoresis (MLEE) (R. Quentin, H. Huet, F.-S. Wang, P. Geslin, A. Goudeau, and R. K. Selander, J. Clin. Microbiol. 33:2576-2581, 1995). Among these 114 strains, there were 92 PFGE patterns. Eleven genetic groups (A to K) were identified with 38% divergence. A more homogeneous group (PFGE group A) was defined, consisting of 73% of the strains previously identified as belonging to a particular MLEE phylogenetic group. A 162-kb fragment was identified as a marker of strains that invaded the central nervous system of neonates. It was detected in 69% of the PFGE patterns obtained with CSF isolates and in only 1.8% of the PFGE patterns obtained with carrier strains. The hylB gene encoding hyaluronate lyase was amplified for all strains in our collection. Ten of 15 isolates belonging to an MLEE subgroup, previously described as being likely to cause invasive infection, had an insertion in the hylB gene (IS1548).


Subject(s)
Genes, Viral , Phylogeny , Polysaccharide-Lyases/genetics , Streptococcal Infections/physiopathology , Streptococcus agalactiae/genetics , Viral Structural Proteins/genetics , Chromosome Mapping , Chromosomes, Bacterial , Electrophoresis, Gel, Pulsed-Field , Genetic Variation , Humans , Infant, Newborn , Restriction Mapping , Serotyping , Streptococcal Infections/microbiology , Streptococcus agalactiae/isolation & purification , Streptococcus agalactiae/pathogenicity
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