The Genus Corynebacterium in the Genomic Era

This chapter will address the main omics approaches used in studies involving the genus Corynebacterium, Gram-positive microorganisms that can be isolated from many diverse environments. Currently, the genus Corynebacterium has more than 130 highly diversified species, many of which present medical, veterinary and biotechnological importance, such as C. diphtheriae, C. pseudotuberculosis, C. ulcerans and C. glutamicum. Due to the wide application in these fields, several omics methodologies are used to better elucidate the species belonging to this genus, such as genomics, transcriptomics and proteomics. The genomic era has contributed to the development of more advanced and complex approaches that enable the increase of generated data, and consequently the advance on the structural, functional and dynamic knowledge of biological systems

Genome Sequence of Corynebacterium pseudotuberculosis MB20 bv. equi Isolated from a Pectoral Abscess of an Oldenburg Horse in California.

The genome of Corynebacterium pseudotuberculosis MB20 bv. equi was sequenced using the Ion Personal Genome Machine (PGM) platform, and showed a size of 2,363,089 bp, with 2,365 coding sequences and a GC content of 52.1%. These results will serve as a basis for further studies on the pathogenicity of C. pseudotuberculosis bv. equi

Extended Spectrum Beta-Lactamase-Producing Gram-Negative Bacteria Recovered From an Amazonian Lake Near the City of Belém, Brazil

Aquatic systems have been described as antibiotic resistance reservoirs, where water may act as a vehicle for the spread of resistant bacteria and resistance genes. We evaluated the occurrence and diversity of third generation cephalosporin-resistant gram-negative bacteria in a lake in the Amazonia region. This water is used for human activities, including consumption after appropriate treatment. Eighteen samples were obtained from six sites in October 2014. Water quality parameters were generally within the legislation limits. Thirty-three bacterial isolates were identified as Escherichia (n = 7 isolates), Acinetobacter, Enterobacter, and Klebsiella (n = 5 each), Pseudomonas (n = 4), Shigella (n = 3), and Chromobacterium, Citrobacter, Leclercia, Phytobacter (1 isolate each). Twenty nine out of 33 isolates (88%) were resistant to most beta-lactams, except carbapenems, and 88% (n = 29) were resistant to antibiotics included in at least three different classes. Among the beta-lactamase genes inspected, the blaCTX–M was the most prevalent (n = 12 positive isolates), followed by blaTEM (n = 5) and blaSHV (n = 4). blaCTX–M–15 (n = 5), blaCTX–M–14 (n = 1) and blaCTX–M–2 (n = 1) variants were detected in conserved genomic contexts: blaCTX–M–15 flanked by ISEcp1 and Orf477; blaCTX–M–14 flanked by ISEcp1 and IS903; and blaCTX–M–2 associated to an ISCR element. For 4 strains the transfer of blaCTX–M was confirmed by conjugation assays. Compared with the recipient, the transconjugants showed more than 500-fold increases in the MICs of cefotaxime and 16 to 32-fold increases in the MICs of ceftazidime. Two isolates (Escherichia coli APC43A and Acinetobacter baumannii APC25) were selected for whole genome analysis. APC43A was predicted as a E. coli pathogen of the high-risk clone ST471 and serotype O154:H18. blaCTX–M–15 as well as determinants related to efflux of antibiotics, were noted in APC43A genome. A. baumannii APC25 was susceptible to carbapenems and antibiotic resistance genes detected in its genome were intrinsic determinants (e.g., blaOXA–208 and blaADC–like). The strain was not predicted as a human pathogen and belongs to a new sequence type. Operons related to metal resistance were predicted in both genomes as well as pathogenicity and resistance islands. Results suggest a high dissemination of ESBL-producing bacteria in Lake Água Preta which, although not presenting characteristics of a strongly impacted environment, contains multi-drug resistant pathogenic strains

Hydrolyzed whey protein enriched with glutamine dipeptide attenuates skeletal muscle damage and improves physical exhaustion test performance in triathletes

PurposeTo investigate the effects of hydrolyzed whey protein enriched with glutamine dipeptide on the percentage of oxygen consumption, second ventilatory threshold, duration and total distance covered, and skeletal muscle damage during an exhaustion test in elite triathletes.MethodsThe study was a randomized, double-blinded, placebo-controlled, crossover trial. Nine male triathletes performed a progressive incremental test on a treadmill ergometer (1.4 km h−1·3 min−1) 30 min after ingesting either 50 g of maltodextrin plus four tablets of 700 mg hydrolyzed whey protein enriched with 175 mg of glutamine dipeptide diluted in 250 ml of water (MGln) or four tablets of 700 mg maltodextrin plus 50 g maltodextrin diluted in 250 ml of water (M). Each athlete was submitted to the two dietary treatments and two corresponding exhaustive physical tests with an interval of one week between the interventions. The effects of the two treatments were then compared within the same athlete. Maximal oxygen consumption, percentage of maximal oxygen consumption, second ventilatory threshold, and duration and total distance covered were measured during the exhaustion test. Blood was collected before and immediately after the test for the determination of plasma lactate dehydrogenase (LDH) and creatine kinase (CK) activities and lactate concentration (also measured 6, 10, and 15 min after the test). Plasma cytokines (IL-6, IL-1β, TNF-α, IL-8, IL-10, and IL-1ra) and C-reactive protein levels were also measured.ResultsA single dose of MGln increased the percentage of maximal oxygen consumption, second ventilatory threshold duration, and total distance covered during the exhaustion test and augmented plasma lactate levels 6 and 15 min after the test. MGln also decreased plasma LDH and CK activities indicating muscle damage protection. Plasma cytokine and C-reactive protein levels did not change across the study periods.ConclusionConditions including overnight fasting and a single dose of MGln supplementation resulted in exercising at a higher percentage of maximal oxygen consumption, a higher second ventilatory threshold, blood lactate levels, and reductions in plasma markers of muscle damage during an exhaustion test in elite triathletes. These findings support oral glutamine supplementation's efficacy in triathletes, but further studies require

Rehabilitation of pediatric patient with microphthalmia, for aesthetic prosthetic eye.

Monografia (graduação)—Universidade de Brasília, 2016.Microftalmia é uma alteração que acontece no desenvolvimento oftálmico. O paciente apresenta um olho com volume reduzido, com funções comprometidas. A prótese ocular estética é um substituto artificial para o bulbo do olho perdido ou atrofiado e, na infância, tem o objetivo de restabelecer a estética facial, mantendo a forma da cavidade anoftálmica, preservando o tônus muscular palpebral, atua mantendo a harmonia e simetria durante o desenvolvimento craniofacial. O objetivo desse trabalho visa apresentar o caso clínico de um paciente que nasceu com microftalmia do bulbo ocular esquerdo, reabilitado com uso de próteses oculares expansoras estéticas. O paciente foi levado pela mãe para o primeiro atendimento para reabilitação aos 7 meses de idade. Imediatamente, foi confeccionada uma prótese a partir de modelos e tamanhos de esclera artificial pré-fabricadas, de acordo com a que melhor se adaptasse à cavidade anoftálmica. A íris artificial foi pintada em disco de cartolina, o mais semelhante possível à cor da íris natural. Após processos laboratoriais, a primeira prótese foi instalada, apresentando tamanho ligeiramente maior do que o tamanho da cavidade, para ampliá-la. Periodicamente, a prótese foi ampliada e trocada, para acompanhar o crescimento da cavidade anoftálmica. O processo de confecção de cada nova prótese seguiu o protocolo da prótese inicial. O paciente tem sido acompanhado por 5 anos. A prótese resulta em uma expansão progressiva da cavidade, consequentemente, promoveu tamanhos aproximados entre as duas órbitas, com aspecto natural. No âmbito psicológico, a mudança da família foi perceptível, gerando melhoria na qualidade de vida do paciente e de seus familiares. Portanto, a reabilitação precoce foi importante para obter o crescimento facial normal, com conforto para o paciente e prevenindo possível cirurgia reparadora futura.Microphthalmia is a change which happens in the ophthalmic development. The patient presents a reduced eye with the functions compromised. The aesthetics eye prosthesis is an artificial substitute for the lost or atrophied eyeball and in childhood it has the objective to restore facial aesthetics by keeping the anophthalmic cavity form, preserving the eyelid muscle tone. The goals of this study is to present the clinical case of a patient who was born with microphthalmia of the left eyeball rehabilitated with aesthetic ocular prostheses expanders. The patient was taken by the mother to the first visit for rehabilitation when he was seven months. Immediately a prosthesis was made from models and sizes of prefabricated artificial sclera according to best adapt the anophthalmic socket cavity. Artificial iris was painted in cardboard disk, the most similar as possible to the color of the natural iris. After laboratorial processes, the first prosthesis was installed, showing size slightly larger than the size of the cavity, to enlarge it. Periodically, the prosthesis was expanded and changed, to follow the growth of the anophtalmic socket cavity. The manufacturing process of each prosthesis followed the protocol of the first one. The patient has been followed by five years. The prosthesis results in a progressive expansion of the cavity, consequently, it promoted approximated sizes between the orbiters with natural aspect. In the psychological scope, the change in the family was noticeable creating quality of life in the patient and in the relatives. Therefore, the early rehabilitation was important to get the normal facial growth with confort to the patient and preventing possible future reconstructive surgery

A Proteomic Perspective on the Bacterial Adaptation to Cold: Integrating OMICs Data of the Psychrotrophic Bacterium Exiguobacterium antarcticum B7

Since the publication of one of the first studies using 2D gel electrophoresis by Patrick H. O’Farrell in 1975, several other studies have used that method to evaluate cellular responses to different physicochemical variations. In environmental microbiology, bacterial adaptation to cold environments is a “hot topic” because of its application in biotechnological processes. As in other fields, gel-based and gel-free proteomic methods have been used to determine the molecular mechanisms of adaptation to cold of several psychrotrophic and psychrophilic bacterial species. In this review, we aim to describe and discuss these main molecular mechanisms of cold adaptation, referencing proteomic studies that have made significant contributions to our current knowledge in the area. Furthermore, we use Exiguobacterium antarcticum B7 as a model organism to present the importance of integrating genomic, transcriptomic, and proteomic data. This species has been isolated in Antarctica and previously studied at all three omic levels. The integration of these data permitted more robust conclusions about the mechanisms of bacterial adaptation to cold

Resistome in Lake Bolonha, Brazilian Amazon: Identification of Genes Related to Resistance to Broad-Spectrum Antibiotics

Resistance to antibiotics is one of the most relevant public health concerns in the world. Aquatic environments play an important role because they are reservoirs for antibiotic resistance genes and antibiotic-resistant strains, contributing to the spread of resistance. The present study investigated the resistome in Lake Bolonha (three sampling sites) in the Amazon region using a metagenomics approach and culture-dependent methods. Whole-metagenome-based results showed that the most abundant phyla were Protobacteria, Actinobacteria, Firmicutes, Bacteroidetes and Cyanobacteria. The composition of the resistome demonstrated that the genes that confer resistance to β-lactams were prevalent at all sampling sites, followed by genes conferring resistance to aminoglycosides and tetracycline. Acquired genes encoding extended-spectrum β-lactamases (e.g., bla CTX-M) and resistance to carbapenems (e.g., bla IMP and bla VIM) were detected through metagenome analysis. Bacteria were isolated from culture medium supplemented with cefotaxime or imipenem, and isolates were identified and analyzed for their antibiotic susceptibility profiles and resistance genes. In total, 98 bacterial isolates belonging to the genera Pseudomonas (37), Acinetobacter (32), Klebsiella (13), Enterobacter (9), Pantoe (3), Stenotrophomonas (3), and Methylobacterium (1) were obtained. Among isolates, the most abundant genes were bla CTX-M (28.3%), bla SHV (22.6%) and bla TEM (18.8%) in isolates from cefotaxime-supplemented medium and bla VIM (28.8%) and bla IMP (22.2%) in isolates recovered from imipenem-supplemented medium. The genes intl1 and intl2 were detected in 19.3% and 7.1% of isolates. Antibiograms showed that 94.9% (from cefotaxime-supplemented medium) and 85.7% (from imipenem-supplemented medium) of the isolates were multidrug resistant. Besides cefotaxime and imipenem, isolates were mostly resistant to aztreonam (91.8%), amoxicillin (98.8%), ampicillin (82.6%), and nalidixic acid (77.5%). Hence, the present study demonstrates that Lake Bolonha is a reservoir of bacteria resistant to antibiotics and resistance genes, some of which are of critical importance to human health

Functional annotation of hypothetical proteins from the <i>Exiguobacterium antarcticum</i> strain B7 reveals proteins involved in adaptation to extreme environments, including high arsenic resistance

<div><p><i>Exiguobacterium antarcticum</i> strain B7 is a psychrophilic Gram-positive bacterium that possesses enzymes that can be used for several biotechnological applications. However, many proteins from its genome are considered hypothetical proteins (HPs). These functionally unknown proteins may indicate important functions regarding the biological role of this bacterium, and the use of bioinformatics tools can assist in the biological understanding of this organism through functional annotation analysis. Thus, our study aimed to assign functions to proteins previously described as HPs, present in the genome of <i>E</i>. <i>antarcticum</i> B7. We used an extensive <i>in silico</i> workflow combining several bioinformatics tools for function annotation, sub-cellular localization and physicochemical characterization, three-dimensional structure determination, and protein-protein interactions. This genome contains 2772 genes, of which 765 CDS were annotated as HPs. The amino acid sequences of all HPs were submitted to our workflow and we successfully attributed function to 132 HPs. We identified 11 proteins that play important roles in the mechanisms of adaptation to adverse environments, such as flagellar biosynthesis, biofilm formation, carotenoids biosynthesis, and others. In addition, three predicted HPs are possibly related to arsenic tolerance. Through an <i>in vitro</i> assay, we verified that <i>E</i>. <i>antarcticum</i> B7 can grow at high concentrations of this metal. The approach used was important to precisely assign function to proteins from diverse classes and to infer relationships with proteins with functions already described in the literature. This approach aims to produce a better understanding of the mechanism by which this bacterium adapts to extreme environments and to the finding of targets with biotechnological interest.</p></div

Workflow used for the annotation of the hypothetical proteins from <i>E</i>. <i>antarcticum</i> B7.

<p>Workflow used for the annotation of the hypothetical proteins from <i>E</i>. <i>antarcticum</i> B7.</p

Three-dimensional structure characteristics for the proteins tested.

<p>Three-dimensional structure characteristics for the proteins tested.</p