ABSTRACT
Speciation with gene flow may be aided by reduced recombination helping to build linkage between genes involved in the early stages of reproductive isolation. Reduced recombination on chromosome X has been implicated in speciation within the Anopheles gambiae complex, species of which represent the major Afrotropical malaria vectors. The most recently diverged, morphologically indistinguishable, species pair, A. gambiae and Anopheles coluzzii, ubiquitously displays a 'genomic island of divergence' spanning over 4 Mb from chromosome X centromere, which represents a particularly promising candidate region for reproductive isolation genes, in addition to containing the diagnostic markers used to distinguish the species. Very low recombination makes the island intractable for experimental recombination studies, but an extreme hybrid zone in Guinea Bissau offers the opportunity for natural investigation of X-island recombination. SNP analysis of chromosome X hemizygous males revealed: (i) strong divergence in the X-island despite a lack of autosomal divergence; (ii) individuals with multiple-recombinant genotypes, including likely double crossovers and localized gene conversion; (iii) recombination-driven discontinuity both within and between the molecular species markers, suggesting that the utility of the diagnostics is undermined under high hybridization. The largely, but incompletely protected nature of the X centromeric genomic island is consistent with a primary candidate area for accumulation of adaptive variants driving speciation with gene flow, while permitting some selective shuffling and removal of genetic variation.
Subject(s)
Anopheles/genetics , Genomic Islands , Hybridization, Genetic , X Chromosome/genetics , Animals , Gene Flow , Genotype , Guinea-Bissau , Male , Polymorphism, Single Nucleotide , Recombination, Genetic , Reproductive IsolationABSTRACT
BACKGROUND: Anopheles darlingi is the main malaria mosquito vector in the Amazonia region. In spite of being considered a riverine, forest-dwelling species, this mosquito is becoming more abundant in peri-urban areas, increasing malaria risk. This has been associated with human-driven environmental changes such as deforestation. METHODS: Microsatellites were used to characterize A. darlingi from seven localities along the Madeira River, Rondônia (Brazil), collected in the early and late periods of the rainy season. RESULTS: Two genetically distinct subpopulations were detected: one (subpopulation A) was associated with the late rainfall period and seems to be ecologically closer to the typical forest A. darlingi; the other (subpopulation B) was associated with the early rainfall period and is probably more adapted to drier conditions by exploiting permanent anthropogenic breeding sites. Results suggest also a pattern of asymmetric introgression, with more subpopulation A alleles introgressed into subpopulation B. Both subpopulations (and admixed mosquitoes) presented similar malaria infection rates, highlighting the potential for perennial malaria transmission in the region. CONCLUSIONS: The co-occurrence of two genetically distinct subpopulations of A. darlingi adapted to different periods of rainfall may promote a more perennial transmission of malaria throughout the year. These findings, in a context of strong environmental impact due to deforestation and dam construction, have serious implications for malaria epidemiology and control in the Amazonian region.
Subject(s)
Anopheles/classification , Anopheles/growth & development , Microsatellite Repeats , Animals , Anopheles/genetics , Brazil , Genotype , SeasonsABSTRACT
BACKGROUND: The malaria vector Anopheles arabiensis exhibits greater behavioural and ecological plasticity than the other major vectors of the Anopheles gambiae complex, which presents challenges for major control methods. This study reports for the first time the presence of An. arabiensis in Antula, a suburb of Bissau city, the capital of Guinea Bissau, where high levels of hybridization between Anopheles coluzzii and An. gambiae have been reported. Given that previous surveys in the area, based on indoor collections, did not sample An. arabiensis, the possibility of a recently introduced exophilic population was investigated. METHODS: Larval and adult mosquito collections were carried out in Antula at the end of the rainy season of 2010. Anopheles gambiae species composition, determined by rDNA-IGS and SINE200X6.1 markers, was compared with four previously collected samples dating back to 1993. Analysis of ten microsatellites was used to estimate levels of genetic diversity, relatedness and to investigate demographic stability. RESULTS: Anopheles arabiensis comprised 54.0% of larvae and 25.6% of adults collected in 2010, but was absent in all previous collections, a highly unlikely observation by chance if the population was stable. This species had the lowest levels of genetic diversity, highest relatedness and, along with An. gambiae, exhibited evidence of a recent population expansion. CONCLUSIONS: Results point to the presence of a previously undetected outdoor population of An. arabiensis in Antula, which appears to have expanded recently, highlighting the importance of complementing indoor-based mosquito collections with sampling methods targeting outdoor adults and immature stages for a more complete assessment of mosquito biodiversity. A change in temporal dynamics in the species complex composition was also detected. Coupled with previous evidence of asymmetric introgression from An. coluzzii to An. gambiae, this suggests that the study area may be subject to ecological changes with a potential impact on both the genetics of these species and on malaria transmission.
Subject(s)
Anopheles/classification , Anopheles/physiology , Behavior, Animal , Disease Vectors , Animals , Anopheles/genetics , Anopheles/growth & development , DNA, Ribosomal/genetics , Entomology/methods , Female , Genotype , Guinea-Bissau , Microsatellite Repeats , Selection BiasABSTRACT
PURPOSE: To describe the clinical manifestations of Vogt-Koyanagi-Harada (VKH) disease during pregnancy and after birth and the therapeutic challenge of treating patients with this condition. METHODS: We describe the clinical manifestations of this disease, as well as the diagnostic tests and treatments performed. RESULTS: The patient was referred for evaluation due to a persistent headache. Examination revealed bilateral anterior uveitis, papillitis and yellowish-white choroidal lesions in both eyes. A tentative diagnosis of VKH disease was made. A multimodal imaging study was performed at the time of presentation and throughout the disease course. The patient was initially treated with intravenous corticosteroids, and subsequently, oral corticosteroids and cyclosporine were administered. Clinical manifestations increased in severity after childbirth. CONCLUSIONS: The clinical course of VKH disease can be modified by pregnancy. While clinical manifestations during gestation may be mild, these may be exacerbated after birth. Treatment with corticosteroids and cyclosporine can be effective.
Subject(s)
Uveomeningoencephalitic Syndrome , Pregnancy , Female , Humans , Uveomeningoencephalitic Syndrome/diagnosis , Uveomeningoencephalitic Syndrome/drug therapy , Cyclosporine/therapeutic use , Disease Progression , Acute Disease , ChoroidABSTRACT
PURPOSE: To describe the presentation and clinical course of a case of endogenous endophthalmitis caused by Clostridium septicum, an anaerobic and gram positive bacteria. METHODS: Observational report of a clinical case presented in Spain. CLINICAL CASE: A 61-year-old male patient was referred to our hospital with a diagnosis of endophthalmitis of his left eye since ten days prior to presentation, and a history of poor response to medical treatment. Evisceration was performed, and C. septicum was isolated from a sample of the vitreous humor. Fourteen days after surgery, the patient returned with orbital cellulitis, and exenteration was performed. Forty-two days after initial presentation, colonoscopy revealed an adenocarcinoma of the proximal colon. Surgical resection of the tumor was performed, and clinical recovery was achieved. CONCLUSIONS: iSystemic C. septicum infection without a traumatic cause has been associated with malignancy, although an initial presentation of endophthalmitis has rarely been reported. In cases of clostridial endogenous endophthalmitis, investigation for colorectal carcinoma is indicated.
Subject(s)
Adenocarcinoma , Clostridium Infections , Clostridium septicum , Colorectal Neoplasms , Endophthalmitis , Adenocarcinoma/complications , Adenocarcinoma/diagnosis , Clostridium Infections/complications , Clostridium Infections/diagnosis , Clostridium Infections/microbiology , Clostridium septicum/physiology , Colorectal Neoplasms/complications , Endophthalmitis/microbiology , Humans , Male , Middle Aged , Observational Studies as TopicABSTRACT
BACKGROUND: Anopheles gambiae M and S molecular forms, the major malaria vectors in the Afro-tropical region, are ongoing a process of ecological diversification and adaptive lineage splitting, which is affecting malaria transmission and vector control strategies in West Africa. These two incipient species are defined on the basis of single nucleotide differences in the IGS and ITS regions of multicopy rDNA located on the X-chromosome. A number of PCR and PCR-RFLP approaches based on form-specific SNPs in the IGS region are used for M and S identification. Moreover, a PCR-method to detect the M-specific insertion of a short interspersed transposable element (SINE200) has recently been introduced as an alternative identification approach. However, a large-scale comparative analysis of four widely used PCR or PCR-RFLP genotyping methods for M and S identification was never carried out to evaluate whether they could be used interchangeably, as commonly assumed. RESULTS: The genotyping of more than 400 A. gambiae specimens from nine African countries, and the sequencing of the IGS-amplicon of 115 of them, highlighted discrepancies among results obtained by the different approaches due to different kinds of biases, which may result in an overestimation of MS putative hybrids, as follows: i) incorrect match of M and S specific primers used in the allele specific-PCR approach; ii) presence of polymorphisms in the recognition sequence of restriction enzymes used in the PCR-RFLP approaches; iii) incomplete cleavage during the restriction reactions; iv) presence of different copy numbers of M and S-specific IGS-arrays in single individuals in areas of secondary contact between the two forms. CONCLUSIONS: The results reveal that the PCR and PCR-RFLP approaches most commonly utilized to identify A. gambiae M and S forms are not fully interchangeable as usually assumed, and highlight limits of the actual definition of the two molecular forms, which might not fully correspond to the two A. gambiae incipient species in their entire geographical range. These limits are discussed and operational suggestions on the choice of the most convenient method for large-scale M- and S-form identification are provided, also taking into consideration technical aspects related to the epidemiological characteristics of different study areas.
Subject(s)
Anopheles/classification , Anopheles/genetics , Entomology/methods , Polymerase Chain Reaction/methods , Polymorphism, Restriction Fragment Length , Africa, Western , Animals , Chromosomes, Insect/genetics , DNA Transposable Elements , DNA, Ribosomal/genetics , DNA, Ribosomal Spacer/genetics , Female , Genotype , Humans , Polymorphism, Single Nucleotide , X Chromosome/geneticsABSTRACT
BACKGROUND: There is a growing concern that global climate change will affect the potential for pathogen transmission by insect species that are vectors of human diseases. One of these species is the former European malaria vector, Anopheles atroparvus. Levels of population differentiation of An. atroparvus from southern Europe were characterized as a first attempt to elucidate patterns of population structure of this former malaria vector. Results are discussed in light of a hypothetical situation of re-establishment of malaria transmission. METHODS: Genetic and phenotypic variation was analysed in nine mosquito samples collected from five European countries, using eight microsatellite loci and geometric morphometrics on 21 wing landmarks. RESULTS: Levels of genetic diversity were comparable to those reported for tropical malaria vectors. Low levels of genetic (0.004 Subject(s)
Anopheles/genetics
, Anopheles/physiology
, Genetic Variation
, Animals
, Anopheles/classification
, Europe
, Geography
, Microsatellite Repeats
, Wings, Animal/anatomy & histology
ABSTRACT
We present the combined results of ab initio and molecular mechanical calculations, computer simulations, and adsorption isotherms investigations of CH(4) adsorbed on HiPco single-walled carbon nanotubes. Isotherms and adsorption energies obtained in our model and simulations are in good agreement with ours and others experimental results. The theoretical analysis conducted for various homogeneous bundles of close-ended and open-ended tubes confirm not only the adsorption in at least two different stages but also the role played by each of the different adsorption sites on the nanotube bundles. The study of different site and nanotube sizes allows us to establish the presence of open tubes in the as-produced HiPco bundles, without regarding the role that adsorption in large interstitial channels may play. Our results also show that predicted scenarios, for the mechanism and the preferential adsorption sites depend on the size of the nanotubes and those of the bundles.
ABSTRACT
BACKGROUND: Resistance of the malaria parasite Plasmodium falciparum to sulfadoxine-pyrimethamine (SP) has evolved worldwide. In the archipelago of São Tomé and Principe (STP), West Africa, although SP resistance is highly prevalent the drug is still in use in particular circumstances. To address the evolutionary origins of SP resistance in these islands, we genotyped point mutations at P. falciparum dhfr and dhps genes and analysed microsatellites flanking those genes. METHODS: Blood samples were collected in July and December 2004 in three localities of São Tomé Island and one in Principe Island. Species-specific nested-PCR was used to identify P. falciparum infected samples. Subsequently, SNPs at the dhfr and dhps genes were identified through PCR-RFLP. Isolates were also analysed for three microsatellite loci flanking the dhfr gene, three loci flanking dhps and four loci located at putative neutral genomic regions. RESULTS: An increase of resistance-associated mutations at dhfr and dhps was observed, in particular for the dhfr/dhps quintuple mutant, associated with clinical SP failure. Analysis of flanking microsatellites suggests multiple independent introductions for dhfr and dhps mutant haplotypes, possibly from West Africa. A reduced genetic diversity and increased differentiation at flanking microsatellites when compared to neutral loci is consistent with a selective sweep for resistant alleles at both loci. CONCLUSIONS: This study provides additional evidence for the crucial role of gene flow and drug selective pressures in the rapid spread of SP resistance in P. falciparum populations, from only a few mutation events giving rise to resistance-associated mutants. It also highlights the importance of human migration in the spread of drug resistant malaria parasites, as the distance between the islands and mainland is not consistent with mosquito-mediated parasite dispersal.
Subject(s)
Antiprotozoal Agents/pharmacology , Drug Resistance , Folic Acid Antagonists/pharmacology , Peptide Synthases/genetics , Plasmodium falciparum/drug effects , Protozoan Proteins/genetics , Tetrahydrofolate Dehydrogenase/genetics , Africa, Western , Child , Child, Preschool , DNA, Protozoan/genetics , Evolution, Molecular , Genotype , Humans , Infant , Infant, Newborn , Malaria, Falciparum/parasitology , Microsatellite Repeats , Plasmodium falciparum/classification , Plasmodium falciparum/genetics , Plasmodium falciparum/isolation & purification , Polymerase Chain ReactionABSTRACT
Sequence variation at the intron-1 of the voltage-gated sodium channel gene in Anopheles gambiae M- and S-forms from Cameroon was assessed to explore the number of mutational events originating knockdown resistance (kdr) alleles. Mosquitoes were sampled between December 2005 and June 2006 from three geographical areas: (i) Magba in the western region; (ii) Loum, Tiko, Douala, Kribi, and Campo along the Atlantic coast; and (iii) Bertoua, in the eastern continental plateau. Both 1014S and 1014F kdr alleles were found in the S-form with overall frequencies of 14% and 42% respectively. Only the 1014F allele was found in the M-form at lower frequency (11%). Analysis of a 455 bp region of intron-1 upstream the kdr locus revealed four independent mutation events originating kdr alleles, here named MS1 -1014F, S1-1014S and S2-1014S kdr-intron-1 haplotypes in S-form and MS3-1014F kdr-intron-1 haplotype in the M-form. Furthermore, there was evidence for mutual introgression of kdr 1014F allele between the two molecular forms, MS1 and MS3 being widely shared by them. Although no M/S hybrid was observed in analysed samples, this wide distribution of haplotypes MS1 and MS3 suggests inter-form hybridizing at significant level and emphasizes the rapid diffusion of the kdr alleles in Africa. The mosaic of genetic events found in Cameroon is representative of the situation in the West-Central African region and highlights the importance of evaluating the spatial and temporal evolution of kdr alleles for a better management of insecticide resistance.
Subject(s)
Anopheles/genetics , Insecticide Resistance/genetics , Polymorphism, Genetic , Sodium Channels/genetics , Alleles , Animals , Cameroon , Genes, Insect , Haplotypes , Introns , Mutation , Sequence Analysis, DNAABSTRACT
The effect of a Lactobacillus spp.-based probiotic (FM-B11) on Salmonella enterica serovar Enteritidis (SE) recovery was evaluated in liquid (Expt. 1) and lyophilized (Expt. 2) forms in two separate experiments with two trials each. For each trial, 80 broiler chicks were randomly allocated into two treatments: control and probiotic culture. All chicks were challenged with SE (approximately 10(4) colony-forming units [cfu]) upon arrival at our laboratory. In both experiments, probiotic culture was administered in the drinking water for 3 consecutive days at a final concentration of approximately 10(6) cfu/ml, beginning 1 hr after SE challenge. Cecal tonsils were aseptically removed at 24 and 72 hr postchallenge, followed by enrichment and plating on xylose lactose deoxycholate (XLD) agar for the presence or absence of Salmonella-typical colonies. In Expt. 1, a significant reduction (P < 0.05) in SE-positive samples was observed in both trials at 24 and 72 hr postchallenge. Additionally, in Expt. 2, the lyophilized probiotic decreased (P < 0.05) SE recovery at both 24 and 72 hr postchallenge compared with the control group in trial 1. In trial 2, SE evaluation was performed only at 72 hr after challenge and fewer (P < 0.001) treated samples were positive for SE. Results showed that application of either liquid or lyophilized probiotic culture in the drinking water for 3 consecutive days can help to reduce SE recovery from young birds, although further research is needed to elucidate the mechanism of this response.
Subject(s)
Chickens/microbiology , Lactobacillus/physiology , Poultry Diseases/therapy , Probiotics/therapeutic use , Salmonella Infections, Animal/therapy , Salmonella enteritidis , Animals , Freeze Drying/veterinary , Poultry Diseases/microbiology , Salmonella Infections, Animal/microbiology , WaterABSTRACT
PURPOSE: To describe the clinical presentations and image findings of a patient with foveal hypoplasia. METHODS: Observational case report of one patient. The clinical presentation of the patient was documented by fluorescein angiography, optical coherence tomography, and optical coherence tomography angiography. RESULTS: A 55-year-old healthy white female with bilateral foveal hypoplasia without nystagmus was presented. There were no signs suggestive of ocular albinism. Absence of foveal depression was noted on both clinical examination and optical coherence tomography. Lack of foveal avascular zone was confirmed on fluorescein angiography and optical coherence tomography angiography. CONCLUSION: To the best of our knowledge this is the first report of findings in foveal hypoplasia examined by angio-optical coherence tomography. Optical coherence tomography angiography is an easy, rapid, and noninvasive tool that allows imaging of the retinal microvasculature without intravenous dye injection.
Subject(s)
Fluorescein Angiography/methods , Fovea Centralis/pathology , Retinal Diseases/diagnosis , Retinal Vessels/pathology , Tomography, Optical Coherence/methods , Visual Acuity , Female , Fundus Oculi , Humans , Middle Aged , Retinal Diseases/physiopathologyABSTRACT
The surface characteristics and adsorbent properties of biomass, obtained from low-cost and environmentally problematic water hyacinth, were determined. Optimum conditions for the elimination of the industrial dye Methyl Red (1) from aqueous solution were established by means of a batch adsorption technique. The ultimate adsorption capacity of water-hyacinth biomass in terms of the elimination of 1 was calculated from a Langmuir-type isotherm as 8.85x10(-2) mol g(-1) at 30 degrees and at an optimum solution pH of 8.0. Dye elimination was found to be associated with strong electrostatic forces (physisorption), the overall process being slightly endergonic (deltaG>0). Our study shows that water hyacinth has a great potential of removing color from wastewater and other dye-polluted aquatic systems.
Subject(s)
Azo Compounds/metabolism , Eichhornia/metabolism , Waste Disposal, Fluid/methods , Water Purification/methods , AdsorptionABSTRACT
Impacts of introgressive hybridisation may range from genomic erosion and species collapse to rapid adaptation and speciation but opportunities to study these dynamics are rare. We investigated the extent, causes and consequences of a hybrid zone between Anopheles coluzzii and Anopheles gambiae in Guinea-Bissau, where high hybridisation rates appear to be stable at least since the 1990s. Anopheles gambiae was genetically partitioned into inland and coastal subpopulations, separated by a central region dominated by A. coluzzii. Surprisingly, whole genome sequencing revealed that the coastal region harbours a hybrid form characterised by an A. gambiae-like sex chromosome and massive introgression of A. coluzzii autosomal alleles. Local selection on chromosomal inversions may play a role in this process, suggesting potential for spatiotemporal stability of the coastal hybrid form and providing resilience against introgression of medically-important loci and traits, found to be more prevalent in inland A. gambiae.
Subject(s)
Anopheles/physiology , Hybridization, Genetic , Whole Genome Sequencing/methods , Animals , Anopheles/classification , Anopheles/genetics , Bayes Theorem , Chromosome Inversion , Gene Flow , Guinea-Bissau , Species SpecificityABSTRACT
Social concern about misuse of antibiotics as growth promoters (AGP) and generation of multidrug-resistant bacteria have restricted the dietary inclusion of antibiotics in livestock feed in several countries. Direct-fed microbials (DFM) are one of the multiple alternatives commonly evaluated as substitutes of AGP. Sporeformer bacteria from the genus Bacillus have been extensively investigated because of their extraordinary properties to form highly resistant endospores, produce antimicrobial compounds, and synthesize different exogenous enzymes. The purpose of the present study was to evaluate and select Bacillus spp. from environmental and poultry sources as DFM candidates, considering their enzyme production profile, biofilm synthesis capacity, and pathogen-inhibition activity. Thirty-one Bacillus isolates were screened for in vitro relative enzyme activity of amylase, protease, lipase, and phytase using a selective media for each enzyme, with 3/31 strains selected as superior enzyme producers. These three isolates were identified as Bacillus subtilis (1/3), and Bacillus amyloliquefaciens (2/3), based on biochemical tests and 16S rRNA sequence analysis. For evaluation of biofilm synthesis, the generation of an adherent crystal violet-stained ring was determined in polypropylene tubes, resulting in 11/31 strains showing a strong biofilm formation. Moreover, all Bacillus strains were evaluated for growth inhibition activity against Salmonella enterica serovar Enteritidis (26/31), Escherichia coli (28/31), and Clostridioides difficile (29/31). Additionally, in previous in vitro and in vivo studies, these selected Bacillus strains have shown to be resistant to different biochemical conditions of the gastrointestinal tract of poultry. Results of the present study suggest that the selection and consumption of Bacillus-DFM, producing a variable set of enzymes and antimicrobial compounds, may contribute to enhanced performance through improving nutrient digestibility, reducing intestinal viscosity, maintaining a beneficial gut microbiota, and promoting healthy intestinal integrity in poultry.
ABSTRACT
Previous studies conducted in our laboratory have demonstrated that intestinal barrier function can be adversely affected by diet ingredients or feed restriction, resulting in increased intestinal inflammation-associated permeability. Two experiments were conducted in broilers to evaluate the effect of three concentrations of Aflatoxin B1 (AFB1; 2, 1.5, or 1 ppm) on gastrointestinal leakage and liver bacterial translocation (BT). In experiment 1, 240 day-of-hatch male broilers were allocated in two groups, each group had six replicates of 20 chickens (n = 120/group): Control feed or feed + 2 ppm AFB1. In experiment 2, 240 day-of-hatch male broilers were allocated in three groups, each group had five replicates of 16 chickens (n = 80/group): Control feed; feed + 1 ppm AFB1; or feed + 1.5 ppm AFB1. In both experiments, chickens were fed starter (days 1-7) and grower diets (days 8-21) ad libitum and performance parameters were evaluated every week. At day 21, all chicks received an oral gavage dose of FITC-d (4.16 mg/kg) 2.5 h before collecting blood samples to evaluate gastrointestinal leakage of FITC-d. In experiment 2, a hematologic analysis was also performed. Liver sections were aseptically collected and cultured using TSA plates to determine BT. Cecal contents were collected to determine total colony-forming units per gram of Gram-negative bacteria, lactic acid bacteria (LAB), or anaerobes by plating on selective media. In experiment 2, liver, spleen, and bursa of Fabricius were removed to determine organ weight ratio, and also intestinal samples were obtained for morphometric analysis. Performance parameters, organ weight ratio, and morphometric measurements were significantly different between Control and AFB1 groups in both experiments. Gut leakage of FITC-d was not affected by the three concentrations of AFB1 evaluated (P > 0.05). Interestingly, a significant reduction in BT was observed in chickens that received 2 and 1 ppm AFB1. An increase (P < 0.05) in total aerobic bacteria, total Gram negatives, and total LAB were observed in chickens fed with 2 and 1.5 ppm of AFB1 when compared with Control and 1 ppm chickens. The integrity of gut epithelial barrier was not compromised after exposure to the mycotoxin.
ABSTRACT
Purpose. To describe the case of spontaneous resolution of epiretinal membrane in a patient with Combined Hamartoma of the Retina and Retinal Pigment Epithelium (CHR-RPE), in the clinical context of Gorlin Syndrome (GS). Methods. Observational case report of a 12-year-old female patient is presented. The diagnosis of CHRRPE was made by OCT and fundus examination, which showed a mound of disorganized tissue originating from retina and retinal pigment epithelium. Epiretinal membrane (EM) was also detected. Genetic study was performed to confirm the diagnosis of GS. Results. The patient was observed for 39 months, showing spontaneous resolution of the traction caused by the EM and improvement in visual acuity (VA), which was 20/80 at initial presentation, rising to 20/40 after follow-up period. Conclusions. The presence of EM in CHR-REP is a cause of reduction of visual acuity. Management of this condition is controversial; however, we would like to highlight that spontaneous resolution of the traction caused by EM is possible, resulting in recovery of VA.
ABSTRACT
Previously, our laboratory has screened and identified Bacillus spp. isolates as direct-fed microbials (DFM). The purpose of the present study was to evaluate the cellulase and xylanase production of these isolates and select the most appropriate Bacillus spp. candidates for DFM. Furthermore, an in vitro digestive model, simulating different compartments of the gastrointestinal tract, was used to determine the effect of these selected candidates on digesta viscosity and Clostridium perfringens proliferation in different poultry diets. Production of cellulase and xylanase were based on their relative enzyme activity. Analysis of 16S rRNA sequence classified two strains as Bacillus amyloliquefaciens and one of the strains as Bacillus subtilis. The DFM was included at a concentration of 10(8) spores/g of feed in five different sterile soybean-based diets containing corn, wheat, rye, barley, or oat. After digestion time, supernatants from different diets were collected to measure viscosity, and C. perfringens proliferation. Additionally, from each in vitro simulated compartment, samples were taken to enumerate viable Bacillus spores using a plate count method after heat-treatment. Significant (P < 0.05) DFM-associated reductions in supernatant viscosity and C. perfringens proliferation were observed for all non-corn diets. These results suggest that antinutritional factors, such as non-starch polysaccharides from different cereals, can enhance viscosity and C. perfringens growth. Remarkably, dietary inclusion of the DFM that produce cellulase and xylanase reduced both viscosity and C. perfringens proliferation compared with control diets. Regardless of diet composition, 90% of the DFM spores germinated during the first 30 min in the crop compartment of the digestion model, followed by a noteworthy increased in the intestine compartment by ~2log10, suggesting a full-life cycle development. Further studies to evaluate in vivo necrotic enteritis effects are in progress.
ABSTRACT
INTRODUCTION AND OBJECTIVE: Acute graft failure (AGF) is defined as significant failure of myocardial function in a newly implanted heart. The aim of the present study was to investigate a series of factors related to heart transplantation (HT) in relation to AGF. MATERIAL AND METHOD: In a study of 287 consecutive HTs performed over a 14-year period, AGF was defined when: a) the surgeon observed ventricular dysfunction before closing the sternotomy; b) various inotropic drugs were required at high doses in the first days after surgery, or c) ventricular dysfunction was identified by routine echocardiography in the immediate postoperative period. Statistical analysis comprised a descriptive and univariate comparative study, followed by multivariate analysis based on application of a logistical regression model. RESULTS: The incidence of AGF was 22%. Predictors of AGF were female donor status (OR = 2.2; 95% CI, 1.2-4.4; p = 0.02), a disproportion of more than 20% in donor-recipient body weight (OR = 2.2; 95% CI, 1.1-4.3; p = 0.02), and background ischemic heart disease (OR = 2.5; 95% CI, 5.5-1.1; p = 0.03) or valve pathology (OR = 5.0; 95% CI, 7.0-1.5; p = 0.01). CONCLUSIONS: AGF is a frequent pathology, which was present in 22% of our heart transplantation patients. Among the modifiable factors related to AGF was a clear disproportion in body weight and the size of grafts from female donors. Unmodifiable factors related to AGF were ischemic heart disease and valvular heart disease as a cause of heart transplantation.
Subject(s)
Graft Rejection/etiology , Heart Transplantation/adverse effects , Acute Disease , Female , Graft Rejection/epidemiology , Heart Transplantation/mortality , Heart Transplantation/statistics & numerical data , Humans , Male , Middle Aged , Multivariate Analysis , Risk FactorsABSTRACT
Rye contains high concentrations of non-starch polysaccharides (NSPs), leading to reduced digestibility. Since poultry have little or no endogenous enzymes capable of hydrolyzing these NSP, exogenous carbohydrases as feed additives are used in an attempt to reduce the anti-nutritional effects of these polysaccharides. Previously, an in vitro study conducted in our laboratory showed that inclusion of certain Bacillus direct-fed microbial (DFM) candidates that produce exogenous phytase, lipase, protease, cellulase, and xylanase in high-NSP diets significantly reduced both digesta viscosity and Clostridium perfringens proliferation. In the present study, rye-based turkey starter diets with or without Bacillus-DFM were administered ad libitum to day-of-hatch turkey poults in two independent experiments. In both experiments, day-of-hatch turkey poults were randomly assigned to either a control diet (CON) or a DFM treated diet (n = 25 birds/group). At 10 days-of-age, all turkey poults from experiments 1 and 2 were weighted and 12 turkey poults/group were randomly selected and humanely killed. Liver samples were aseptically collected to evaluate bacterial translocation, and intestinal digesta samples were individually collected to evaluate viscosity. Additionally, in experiment 2 both tibias were removed for assessment of bone parameters. In both experiments, the treated group showed a reduction in the total number of coliforms in the liver and a reduced digesta viscosity when compared to the CON group (P < 0.05). Turkey poults fed the Bacillus-DFM candidate had increased tibia diameter, breaking strength, ash content, calcium content, and phosphorus content when compared with CON turkey poults. In summary, turkey poults fed with a rye-based diet without DFM showed an increase in bacterial translocation and digesta viscosity, accompanied by a reduction in bone mineralization; however, these adverse effects can be prevented by the inclusion of selected a Bacillus-DFM candidate in high-NSP diets.