Rapid detection and differentiation of mycobacterial species using a multiplex PCR system

Introduction The early diagnosis of mycobacterial infections is a critical step for initiating treatment and curing the patient. Molecular analytical methods have led to considerable improvements in the speed and accuracy of mycobacteria detection. Methods The purpose of this study was to evaluate a multiplex polymerase chain reaction system using mycobacterial strains as an auxiliary tool in the differential diagnosis of tuberculosis and diseases caused by nontuberculous mycobacteria (NTM) Results Forty mycobacterial strains isolated from pulmonary and extrapulmonary origin specimens from 37 patients diagnosed with tuberculosis were processed. Using phenotypic and biochemical characteristics of the 40 mycobacteria isolated in LJ medium, 57.5% (n=23) were characterized as the Mycobacterium tuberculosis complex (MTBC) and 20% (n=8) as nontuberculous mycobacteria (NTM), with 22.5% (n=9) of the results being inconclusive. When the results of the phenotypic and biochemical tests in 30 strains of mycobacteria were compared with the results of the multiplex PCR, there was 100% concordance in the identification of the MTBC and NTM species, respectively. A total of 32.5% (n=13) of the samples in multiplex PCR exhibited a molecular pattern consistent with NTM, thus disagreeing with the final diagnosis from the attending physician. Conclusions Multiplex PCR can be used as a differential method for determining TB infections caused by NTM a valuable tool in reducing the time necessary to make clinical diagnoses and begin treatment. It is also useful for identifying species that were previously not identifiable using conventional biochemical and phenotypic techniques.

The BACTEC MGIT(tm) 320 system as a laboratory tool to diagnose tuberculosis in a Brazilian hospital with a high prevalence of HIV infection

Abstract: INTRODUCTION: The World Health Organization endorses the BACTEC Mycobacterial Growth Indicator Tube (MGIT)(tm) system as a rapid, sensitive, and specific method to diagnostic of tuberculosis. Here, we compared the performance of this system against Ogawa-Kudoh cultures and microscopy. METHODS: A total of 927 samples were obtained between December 2011 and December 2013 from 652 cases of suspected tuberculosis at the School Hospital of the Federal University of Rio Grande in Brazil. RESULTS: The MGIT system confirmed tuberculosis in more cases in less time. CONCLUSIONS: The MGIT system is an effective tool for early diagnosis of tuberculosis, especially in patients with HIV/AIDS.

Blood Pressure Variation Throughout Pregnancy According to Early Gestational BMI: A Brazilian Cohort

Background: The maternal cardiovascular system undergoes progressive adaptations throughout pregnancy, causing blood pressure fluctuations. However, no consensus has been established on its normal variation in uncomplicated pregnancies. Objective: To describe the variation in systolic blood pressure (SBP) and diastolic blood pressure (DBP) levels during pregnancy according to early pregnancy body mass index (BMI). Methods: SBP and DBP were measured during the first, second and third trimesters and at 30-45 days postpartum in a prospective cohort of 189 women aged 20-40 years. BMI (kg/m2) was measured up to the 13th gestational week and classified as normal-weight (<25.0) or excessive weight (≥25.0). Longitudinal linear mixed-effects models were used for statistical analysis. Results: A decrease in SBP and DBP was observed from the first to the second trimester (βSBP=-0.394; 95%CI: -0.600- -0.188 and βDBP=-0.617; 95%CI: -0.780- -0.454), as was an increase in SBP and DBP up to 30-45 postpartum days (βSBP=0.010; 95%CI: 0.006-0.014 and βDBP=0.015; 95%CI: 0.012-0.018). Women with excessive weight at early pregnancy showed higher mean SBP in all gestational trimesters, and higher mean DBP in the first and third trimesters. Excessive early pregnancy BMI was positively associated with prospective changes in SBP (βSBP=7.055; 95%CI: 4.499-9.610) and in DBP (βDBP=3.201; 95%CI: 1.136-5.266). Conclusion: SBP and DBP decreased from the first to the second trimester and then increased up to the postpartum period. Women with excessive early pregnancy BMI had higher SBP and DBP than their normal-weight counterparts throughout pregnancy, but not in the postpartum period.

Cardiac Sympathetic Hyperactivity after Chemotherapy: Early Sign of Cardiotoxicity?

Background:Chemotherapy with anthracyclines and trastuzumab can cause cardiotoxicity. Alteration of cardiac adrenergic function assessed by metaiodobenzylguanidine labeled with iodine-123 (123I-mIBG) seems to precede the drop in left ventricular ejection fraction.Objective:To evaluate and to compare the presence of cardiovascular abnormalities among patients with breast cancer undergoing chemotherapy with anthracyclines and trastuzumab, and only with anthracycline.Methods:Patients with breast cancer were analyzed clinical, laboratory, electrocardiographic and echocardiographic and cardiac sympathetic activity. In scintigraphic images, the ratio of 123I-mIBG uptake between the heart and mediastinum, and the washout rate were calculated. The variables were compared between patients who received anthracyclines and trastuzumab (Group 1) and only anthracyclines (Group 2).Results:Twenty patients, with mean age 57 ± 14 years, were studied. The mean left ventricular ejection fraction by echocardiography was 67.8 ± 4.0%. Mean washout rate was 28.39 ± 9.23% and the ratio of 123I-mIBG uptake between the heart and mediastinum was 2.07 ± 0.28. Of the patients, 82% showed an increased in washout rate, and the ratio of 123I-mIBG uptake between the heart and mediastinum decreased in 25%. Concerning the groups, the mean washout rate of Group 1 was 32.68 ± 9.30% and of Group 2 was 24.56 ± 7.72% (p = 0,06). The ratio of 123I-mIBG uptake between the heart and mediastinum was normal in all patients in Group 2, however, the Group 1, showed 50% the ratio of 123I-mIBG uptake between the heart and mediastinum ≤ 1.8 (p = 0.02).Conclusion:In women with breast cancer undergoing chemotherapy, assessment of cardiac sympathetic activity with 123I-mIBG appears to be an early marker of cardiotoxicity. The combination of chemotherapy showed higher risk of cardiac adrenergic hyperactivity.

The early use of yellow fever virus strain 17D for vaccine production in Brazil - a review

The use of yellow fever (YF) virus 17D strain for vaccine production adapted in Brazil since its introduction in 1937 was reviewed. This was possible due to the availability of official records of vaccine production. The retrieved data highlight the simultaneous use of several serially passaged 17D substrain viruses for both inocula and vaccine preparation that allowed uninterrupted production. Substitution of these substrain viruses became possible with the experience gained during quality control and human vaccination. Post-vaccinal complications in humans and the failure of some viruses in quality control tests (neurovirulence for monkeys) indicated that variables needed to be reduced during vaccine production, leading to the development of the seed lot system. The 17DD substrain, still used today, was the most frequently used substrain and the most reliable in terms of safety and efficacy. For this reason, it is possible to derive an infectious cDNA clone of this substrain combined with production in cell culture that could be used to direct the expression of heterologous antigens and lead to the development of new live vaccines.

Toxoplasma gondii and the Immunity-Related GTPase (IRG) resistance system in mice: a review

The Immunity Related GTPases (IRG proteins) constitute a large family of interferon-inducible proteins that mediate early resistance to Toxoplasma gondii infection in mice. At least six members of this family are required for resistance of mice to virulent T. gondii strains. Recent results have shown that the complexity of the resistance arises from complex regulatory interactions between different family members. The mode of action against T. gondii depends on the ability of IRG proteins to accumulate on the parasitophorous vacuole of invading tachyzoites and to induce local damage to the vacuole resulting in disruption of the vacuolar membrane. Virulent strains of T. gondiiovercome the IRG resistance system, probably by interfering with the loading of IRG proteins onto the parasitophorous vacuole membrane. It may be assumed that T. gondii strains highly virulent for mice will be disadvantaged in the wild due to the rapid extinction of the infected host, while it is self-evident that susceptibility to virulent strains is disadvantageous to the mouse host. We consider the possibility that this double disadvantage is compensated in wild populations by segregating alleles with different resistance and susceptibility properties in the IRG system.

Schistogram changes after administration of antischistosomal drugs in mice at the early phase of Schistosoma mansoni infection

Mice infected with Schistosoma mansoni were treated with oxamniquine, praziquantel, artesunate at the pre-patent phase, aiming at observing schistogram alterations. Half of the animals were perfused five days post-treatment for counting and classification of immature worms, based on pre-established morphological criteria (schistogram); the remaining animals were evaluated 42 or 100 days after infection and perfusion of the portal-system was performed for collection and counting of adult worms and oogram. It was observed that oxamniquine and artesunate treatment administered at the pre-postural phase causes significant reduction in the number of immature and adult worms. However, there was little reduction with praziquantel when used at the dose of 400 mg/kg for treatments administered 14, 15, 21 or 23 days post-infection. Artesunate was responsible for significant alterations in development of young worms, as well as for a higher number of worms presenting intestinal damages. Immature adult worms were detected in mice treated with artesunate or oxamniquine at the pre-patent phase of infection and recovered by perfusion 100 days after infection. Schistogram proved to be a very useful tool for experimental evaluation of the activity of antischistosomal drugs and a good model to identify the most sensitive stages to drugs.

Early postnatal hospital discharge: the consequences of reducing length of stay for women and newborns

The objective of this study is to examine the literature and identify most salient outcomes of early postnatal discharge for women, newborns and the health system. An electronic search strategy was designed including the following sources: Web of Science, Scopus, ProQuest and PubMed/MEDLINE, using the following terms: (early AND discharge) OR (length AND stay) AND (postpartum OR postnatal) AND (effect* OR result OR outcome). Content analysis was used to identify and summarise the findings and methods of the research papers. The evidence available is not enough to either reject or support the practice of early postnatal discharge; different studies have reported different outcomes for women and newborns. The need of systematic clinical research is discussed.

Early Changes in Soil Metabolic Diversity and Bacterial Community Structure in Sugarcane under Two Harvest Management Systems

Preharvest burning is widely used in Brazil for sugarcane cropping. However, due to environmental restrictions, harvest without burning is becoming the predominant option. Consequently, changes in the microbial community are expected from crop residue accumulation on the soil surface, as well as alterations in soil metabolic diversity as of the first harvest. Because biological properties respond quickly and can be used to monitor environmental changes, we evaluated soil metabolic diversity and bacterial community structure after the first harvest under sugarcane management without burning compared to management with preharvest burning. Soil samples were collected under three sugarcane varieties (SP813250, SP801842 and RB72454) and two harvest management systems (without and with preharvest burning). Microbial biomass C (MBC), carbon (C) substrate utilization profiles, bacterial community structure (based on profiles of 16S rRNA gene amplicons), and soil chemical properties were determined. MBC was not different among the treatments. C-substrate utilization and metabolic diversity were lower in soil without burning, except for the evenness index of C-substrate utilization. Soil samples under the variety SP801842 showed the greatest changes in substrate utilization and metabolic diversity, but showed no differences in bacterial community structure, regardless of the harvest management system. In conclusion, combined analysis of soil chemical and microbiological data can detect early changes in microbial metabolic capacity and diversity, with lower values in management without burning. However, after the first harvest, there were no changes in the soil bacterial community structure detected by PCR-DGGE under the sugarcane variety SP801842. Therefore, the metabolic profile is a more sensitive indicator of early changes in the soil microbial community caused by the harvest management system.

Cucumber seedling dependence on cotyledonary leaves for early growth

The objective of this work was to evaluate the dependence of cucumber (Cucumis sativus L.) seedlings on cotyledonary leaves for early growth and establishment. Sets of two uniform emerging seedlings were used to quantify the initial growth and dry matter accumulation, as well as the intensity and stage of cotyledon damage in seedling establishment and to determine cotyledon protein, amino acid and carbohydrate contributions to the growing seedling. Cucumber seedling establishment was found to be highly dependent on cotyledonary leaves. Root system establishment was highly dependent on the health of the aerial part. One cotyledon was enough to maintain aerial growth of seedlings after unfolding the first true leaf. Cucumber seedlings depended on both cotyledons to keep root system growth at least until leaf area was equivalent to cotyledon area. Covering one or both cotyledons of seedlings with one unfolded leaf increased carbohydrate content of uncovered cotyledon and leaves compared with control seedlings. Cucumber seedlings are highly dependent on cotyledonary leaves and aerial parts are less dependent than root system. Cotyledon damage at early stages of plant establishment would adversely impact crop yield by reducing plant density, an important yield component, or slowing down seedling growth and establishment.

Eucalyptus growth in silvopastoral system under different crown dia meters

The aim of this study was to evaluate the effect of different crown diameters on the early growth of eucalyptus intercropped with Brachiaria decumbens in a silvopastoral system. The experiment was conducted in a B. decumbens established pasture, where hybrid eucalyptus urograndis (clone GG100) was planted, spaced 8 x 3 m. A randomized block design was used, with six replicates. Treatments consisted of five crown diameters (0.0, 1.0, 1.5, 2.0, and 3.0 m) surrounding the eucalyptus plants. Five weeding hoes were performed throughout the experiment, according to the different crown diameters, aiming to maintain the eucalyptus plants free from B. decumbens interference. At 90, 180, 270, and 360 DAP, the height and the diameter of the eucalyptus plants were evaluated, and at 360 DAP, surface biomass and leaf area were evaluated. At 90 DAP, it was verified that the non-weeded plants had lower growth, compared to those submitted to crowns. Crown diameters of 2.51 and 2.64 m allowed greater growth in height and diameter at ground level of eucalyptus plants, respectively, in all periods evaluated. Biomass production and leaf area per plant at 360 DAP were also influenced by the different crown diameters. It was concluded that crown diameter around 2 meters provided favorable conditions for early growth of eucalyptus and less involvement in the area occupied by forage.

Early growth of common bean cropped over ruzigrass residues

Ruzigrass (Brachiaria ruziziensis, syn. Urochloa ruziziensis) is used as a cover crop in tropical regions because it has a high yield potential, is widely adapted and has a vigorous root system. However, it may affect early growth of the next crop due to allelopathy and competition for soil nitrate. A greenhouse experiment was conducted in glass-walled pots with soil to determine the effect of ruzigrass residues on the initial growth and mineral nutrition of common bean (Phaseolus vulgaris). Ruzigrass was grown in the pots for 50 days and chemically desiccated. Then, common bean was grown: without ruzigrass residues; with ruzigrass shoots placed on the soil surface; with ruzigrass roots left in the soil; and with ruzigrass shoots and roots left undisturbed. Root growth of common bean was decreased by ruzigrass residues, but shoot biomass was not affected when it was grown in the presence of ruzigrass shoots or roots alone. In pots where ruzigrass residues were undisturbed, common bean biomass yield was decreased. Nitrogen concentration in common bean shoot was not affected by ruzigrass shoot on the soil surface, an evidence that the observed decrease in common bean growth probably was due to allelopathic effects rather than competition for nitrogen.

Induction of cell-mediated immunity during early stages of infection with intracellular protozoa

Toxoplasma gondii and Trypanosoma cruzi are intracellular parasites which, as part of their life cycle, induce a potent cell-mediated immunity (CMI) maintained by Th1 lymphocytes and IFN-g. In both cases, induction of a strong CMI is thought to protect the host against rapid parasite multiplication and consequent pathology and lethality during the acute phase of infection. However, the parasitic infection is not eliminated by the immune system and the vertebrate host serves as a parasite reservoir. In contrast, Leishmania sp, which is a slow growing parasite, appears to evade induction of CMI during early stages of infection as a strategy for surviving in a hostile environment (i.e., inside the macrophages which are their obligatory niche in the vertebrate host). Recent reports show that the initiation of IL-12 synthesis by macrophages during these parasitic infections is a key event in regulating CMI and disease outcome. The studies reviewed here indicate that activation/inhibition of distinct signaling pathways and certain macrophage functions by intracellular protozoa are important events in inducing/modulating the immune response of their vertebrate hosts, allowing parasite and host survival and therefore maintaining parasite life cycles.

Signaled two-way avoidance learning using electrical stimulation of the inferior colliculus as negative reinforcement: effects of visual and auditory cues as warning stimuli

The inferior colliculus is a primary relay for the processing of auditory information in the brainstem. The inferior colliculus is also part of the so-called brain aversion system as animals learn to switch off the electrical stimulation of this structure. The purpose of the present study was to determine whether associative learning occurs between aversion induced by electrical stimulation of the inferior colliculus and visual and auditory warning stimuli. Rats implanted with electrodes into the central nucleus of the inferior colliculus were placed inside an open-field and thresholds for the escape response to electrical stimulation of the inferior colliculus were determined. The rats were then placed inside a shuttle-box and submitted to a two-way avoidance paradigm. Electrical stimulation of the inferior colliculus at the escape threshold (98.12 ± 6.15 (A, peak-to-peak) was used as negative reinforcement and light or tone as the warning stimulus. Each session consisted of 50 trials and was divided into two segments of 25 trials in order to determine the learning rate of the animals during the sessions. The rats learned to avoid the inferior colliculus stimulation when light was used as the warning stimulus (13.25 ± 0.60 s and 8.63 ± 0.93 s for latencies and 12.5 ± 2.04 and 19.62 ± 1.65 for frequencies in the first and second halves of the sessions, respectively, P<0.01 in both cases). No significant changes in latencies (14.75 ± 1.63 and 12.75 ± 1.44 s) or frequencies of responses (8.75 ± 1.20 and 11.25 ± 1.13) were seen when tone was used as the warning stimulus (P>0.05 in both cases). Taken together, the present results suggest that rats learn to avoid the inferior colliculus stimulation when light is used as the warning stimulus. However, this learning process does not occur when the neutral stimulus used is an acoustic one. Electrical stimulation of the inferior colliculus may disturb the signal transmission of the stimulus to be conditioned from the inferior colliculus to higher brain structures such as amygdala

Rapid detection of multidrug-resistant Mycobacterium tuberculosis using the mycobacteria growth indicator tube (MGIT) system

The emergence of multidrug-resistant strains of Mycobacterium tuberculosis has increased the need for rapid drug susceptibility tests, which are needed for adequate patient treatment. The objective of the present study was to evaluate the mycobacteria growth indicator tube (MGIT) system to detect multidrug-resistant M. tuberculosis strains. The MGIT system was compared with two standard methods (proportion and resistance ratio methods). One hundred clinical M. tuberculosis isolates [25 susceptible to isoniazid (INH) and rifampicin (RIF), 20 resistant to INH, 30 resistant to INH-RIF, and 25 resistant to INH-RIF and other drugs] obtained in the State of São Paulo were tested for INH and RIF susceptibility. Full agreement among the tests was found for all sensitive and all INH-resistant strains. For RIF-resistant strains results among the tests agreed for 53 (96.4%) of 55 isolates. Results were obtained within 6 days (range, 5 to 8 days), 28 days and 12 days when using MGIT, the proportion method and the resistance ratio methods, respectively. The MGIT system presented an overall agreement of 96% when compared with two standard methods. These data show that the MGIT system is rapid, sensitive and efficient for the early detection of multidrug-resistant M. tuberculosis.