Comparison of the reproductive behavior between isolated Peckia chrysostoma (Wiedemann, 1830) and Adiscochaeta ingens (Walker, 1849) (Diptera: Sarcophagidae) females reared in laboratory

In both species, maintained under laboratory environmental conditions, anautogeny was comproved and all females that had free access to proteic source were fertiles. We obtained the following average values for Peckiachrysostoma: 59.7 ± 15.6 and 81.8 ± 15.4 days of longevity in the respective cases of free access and no access to proteic source, 21.4 ± 4.3 days of pre-larviposition period and 35.2 ± 16.5 days of larviposition period, 5.3 ± 1.8 larvipositions female with 7.0 ± 1.1 days of periodicity, 35.7 ± 6.1 larvae per larviposition leading to a total number of 183.8 ± 69.2 viable larvae per female and 94.8% ± 5.3% of productivity. The mean number of ovarioles per female was 56.4 ± 9.8, resulting in a reproductive potential of 63.3%. For Adiscochaeta ingens, the obtained average values were: 41.3 ± 6.3 and 52 ± 13.1 days of longevity in the respective cases of free access and no access to proteic source, 15.3 ± 1.7 days of pre-larviposition period and 21.5 ± 7.5 days of larviposition period, 3 ± 0.7 larvipositions per female with 10.4 ± 0.8 days of periodicity, 30.3 ± 8.2 larvae per larviposition leading to a total number of 78.5 ± 21.7 viable larvae per female and 90.1% ± 16% of productivity. The mean number of ovarioles per female was 54.6 ± 5.2, resulting in a reproductive potential of 55.5%. Within applied parameters, the values obtained for P. chrysostoma demonstrate its superior productivity in comparison with A. ingens

Molecular mechanisms of drug resistance in clinical Candida species isolated from tunisian hospitals.

Antifungal resistance of Candida species is a clinical problem in the management of diseases caused by these pathogens. In this study we identified from a collection of 423 clinical samples taken from Tunisian hospitals two clinical Candida species (Candida albicans JEY355 and Candida tropicalis JEY162) with decreased susceptibility to azoles and polyenes. For JEY355, the fluconazole (FLC) MIC was 8 μg/ml. Azole resistance in C. albicans JEY355 was mainly caused by overexpression of a multidrug efflux pump of the major facilitator superfamily, Mdr1. The regulator of Mdr1, MRR1, contained a yet-unknown gain-of-function mutation (V877F) causing MDR1 overexpression. The C. tropicalis JEY162 isolate demonstrated cross-resistance between FLC (MIC > 128 μg/ml), voriconazole (MIC > 16 μg/ml), and amphotericin B (MIC > 32 μg/ml). Sterol analysis using gas chromatography-mass spectrometry revealed that ergosterol was undetectable in JEY162 and that it accumulated 14α-methyl fecosterol, thus indicating a perturbation in the function of at least two main ergosterol biosynthesis proteins (Erg11 and Erg3). Sequence analyses of C. tropicalis ERG11 (CtERG11) and CtERG3 from JEY162 revealed a deletion of 132 nucleotides and a single amino acid substitution (S258F), respectively. These two alleles were demonstrated to be nonfunctional and thus are consistent with previous studies showing that ERG11 mutants can only survive in combination with other ERG3 mutations. CtERG3 and CtERG11 wild-type alleles were replaced by the defective genes in a wild-type C. tropicalis strain, resulting in a drug resistance phenotype identical to that of JEY162. This genetic evidence demonstrated that CtERG3 and CtERG11 mutations participated in drug resistance. During reconstitution of the drug resistance in C. tropicalis, a strain was obtained harboring only defective Cterg11 allele and containing as a major sterol the toxic metabolite 14α-methyl-ergosta-8,24(28)-dien-3α,6β-diol, suggesting that ERG3 was still functional. This strain therefore challenged the current belief that ERG11 mutations cannot be viable unless accompanied by compensatory mutations. In conclusion, this study, in addition to identifying a novel MRR1 mutation in C. albicans, constitutes the first report on a clinical C. tropicalis with defective activity of sterol 14α-demethylase and sterol Δ(5,6)-desaturase leading to azole-polyene cross-resistance.

Purification and activity standardisation of a (166m)Ho solution.

As part of a project to use the long-lived (T(1/2)=1200a) (166m)Ho as reference source in its reference ionisation chamber, IRA standardised a commercially acquired solution of this nuclide using the 4pibeta-gamma coincidence and 4pigamma (NaI) methods. The (166m)Ho solution supplied by Isotope Product Laboratories was measured to have about 5% Europium impurities (3% (154)Eu, 0.94% (152)Eu and 0.9% (155)Eu). Holmium had therefore to be separated from europium, and this was carried out by means of ion-exchange chromatography. The holmium fractions were collected without europium contamination: 162h long HPGe gamma measurements indicated no europium impurity (detection limits of 0.01% for (152)Eu and (154)Eu, and 0.03% for (155)Eu). The primary measurement of the purified (166m)Ho solution with the 4pi (PC) beta-gamma coincidence technique was carried out at three gamma energy settings: a window around the 184.4keV peak and gamma thresholds at 121.8 and 637.3keV. The results show very good self-consistency, and the activity concentration of the solution was evaluated to be 45.640+/-0.098kBq/g (0.21% with k=1). The activity concentration of this solution was also measured by integral counting with a well-type 5''x5'' NaI(Tl) detector and efficiencies computed by Monte Carlo simulations using the GEANT code. These measurements were mutually consistent, while the resulting weighted average of the 4pi NaI(Tl) method was found to agree within 0.15% with the result of the 4pibeta-gamma coincidence technique. An ampoule of this solution and the measured value of the concentration were submitted to the BIPM as a contribution to the Système International de Référence.

Burkholderia sartisoli sp. nov., isolated from a polycyclic aromatic hydrocarbon-contaminated soil.

A Gram-negative, rod-shaped, aerobic bacterium, designated strain RP007(T), was isolated from a polycyclic aromatic hydrocarbon-contaminated soil in New Zealand. Two additional strains were recovered from a compost heap in Belgium (LMG 18808) and from the rhizosphere of maize in the Netherlands (LMG 24204). The three strains had virtually identical 16S rRNA gene sequences and whole-cell protein profiles, and they were identified as members of the genus Burkholderia, with Burkholderia phenazinium as their closest relative. Strain RP007(T) had a DNA G+C content of 63.5 mol% and could be distinguished from B. phenazinium based on a range of biochemical characteristics. Strain RP007(T) showed levels of DNA-DNA relatedness towards the type strain of B. phenazinium and those of other recognized Burkholderia species of less than 30 %. The results of 16S rRNA gene sequence analysis, DNA-DNA hybridization experiments and physiological and biochemical tests allowed the differentiation of strain RP007(T) from all recognized species of the genus Burkholderia. Strains RP007(T), LMG 18808 and LMG 24204 are therefore considered to represent a single novel species of the genus Burkholderia, for which the name Burkholderia sartisoli sp. nov. is proposed. The type strain is RP007(T) (=LMG 24000(T) =CCUG 53604(T) =ICMP 13529(T)).

A Modulated Closed Form solution for Quantitative Susceptibility Mapping - A thorough evaluation and comparison to iterative methods based on edge prior knowledge.

The aim of this study is to perform a thorough comparison of quantitative susceptibility mapping (QSM) techniques and their dependence on the assumptions made. The compared methodologies were: two iterative single orientation methodologies minimizing the l2, l1TV norm of the prior knowledge of the edges of the object, one over-determined multiple orientation method (COSMOS) and anewly proposed modulated closed-form solution (MCF). The performance of these methods was compared using a numerical phantom and in-vivo high resolution (0.65mm isotropic) brain data acquired at 7T using a new coil combination method. For all QSM methods, the relevant regularization and prior-knowledge parameters were systematically changed in order to evaluate the optimal reconstruction in the presence and absence of a ground truth. Additionally, the QSM contrast was compared to conventional gradient recalled echo (GRE) magnitude and R2* maps obtained from the same dataset. The QSM reconstruction results of the single orientation methods show comparable performance. The MCF method has the highest correlation (corrMCF=0.95, r(2)MCF =0.97) with the state of the art method (COSMOS) with additional advantage of extreme fast computation time. The l-curve method gave the visually most satisfactory balance between reduction of streaking artifacts and over-regularization with the latter being overemphasized when the using the COSMOS susceptibility maps as ground-truth. R2* and susceptibility maps, when calculated from the same datasets, although based on distinct features of the data, have a comparable ability to distinguish deep gray matter structures.

Genetic complementation analysis of two independently isolated hycanthone-resistant strains of Schistosoma mansoni

The objective of this study is to determine whether various hycanthone resistant strains of schistosomes which have been independently isolated are all affected in the same gene. A strain obtained from a Brazilian patient was compared with a strain of Puerto Rican origin selected in the laboratory. If the mutation conferring resistance involved two different genes, one would expect that the progeny of a cross between the two strains would show complementation, i.e. it would be sensitive to the drug. We have performed such a cross and obtained F1 hybrid worms wich were essentially all resistant, thus suggesting that the mutation conferring resistance in the two strains involves the same gene.

Factors conditioning the habitat and the density of Biomphalaria tenagophila (Orbigny, 1835) in an isolated schistosomiasis focus in Rio de Janeiro city

The present work was carried out in a watercress garden in Alto da Boa Vista, in the city of Rio de Janeiro, Brazil. The investigation was carried out in two phases. The first one (1985-86) involved the sampling of Biomphalaria tenegophila in two areas to determine its relative populational densities. The results showed that the populations presented similar densities and dynamics. The second phase (1988-89) involved the study of the influence of some environmental factors on the establishment of B. tenagophila in watercress garden. Two factors were identified as responsible for the establishment of B. tenagophila in the garden: (1) the quality of the water entering the irrigation system, to which domestic sewage is added, and (2) alterations in the nature of the substrate, due to inadequate fertilization techniques, which employ organic matter from adjacent pigsties. Aquatic plants and hydrological parameters of the irrigation system were subsidiary factors to the establishment of B. tenagophila in the garden.

Crithidia ricardoi sp. n. a new species of trypanosomatidae isolated from Culex saltanensis Dyar, 1928 (Diptera: Culicidae)

A flagellte trypanosomatid was isolated in culture from the digestive tract of the mosquito Culex saltanensis Dyar, 1928. It grows exuberantly in liver infusion in the form of epimastigotes and choanomastigotes typical of the genus Crithidia. The trypanosomatid was compared to C. deanei, C. fasciculata, C. luciliae, C. oncopelti and C. guilhermei. The techniques used for comparison were electron transmission microscopy, isoenzymes and kDNA restriction profiles. No endosymbionts were found at electron microscopy. Results for the biochemical methods employd indicate that the trypanosomatid isolated from C. saltanensis is a new species of Crithidia. The name C. ricardoi sp. n. is proposed for thes new species.

Survey of the irp2 gene among Yersinia pestis strains isolated during several plague outbreaks in northeast Brazil

The irp2 gene codes for a 190 kDa protein (HMWP2) synthesidez when highly pathogenic Yersinia are grown under conditions of iron starvation. In this work, the presence of irp2 in strains of Y. pestis isolated from different hosts during several plague outbreaks in the foci of Northeast Brazil wasstudied. For this purpose, 53 strains were spotted onto nylon filters and their DNA was hybridized with the A13 probe which is a 1 kb fragment of the irp2 coding sequence. All strains except two hybridized with the probe. However, when the initial stock culture of these two strains were analyzed, they both proved to bepositive with the A13 probe, indicating that the locus was lost after subculturein vitro but was always present in vivo. To examine the degree of conservation of the chromosomal fragment carrying irp2 among Brazilian strains, the hybridization profiles of 15 strains from different outbreaks, different hosts and different foci were compared. The hybridization profiles of these strains were all identical when their DNA was digested with either EcoRI, EcorRV or AvaII, indicatingthat the restriction sites surrounding the irp2 locus are very well conserved among Northeast Brazilian strains of Y. pestis. Altogether, these results suggest that the irp2 chromosomal region should be of prime importance for the bacteria during their multiplication in the host.

Intratypic differentiation of polioviruses isolated from suspected cases of poliomyelitis in Brazil during the period of 1990 to 1993

This study analyzed 3129 fecal samples derived from 1626 patients with sudden onset acute flaccid paralysis clinically compatible with poliomyelitis. The samples were collected in the period ranging from January 1990 to September 1993 in all regions of Brazil. Among the 1626 cases studied, 196 had isolation of poliovirus. Nevertheless, it was observed that some factors influenced the isolation rate and the intratypic characterization of these polioviruses. No cases of acute flaccid paralysis has been found to be etiologically related with wild polioviruses.

CHO expression of a novel human recombinant IgG1 anti-RhD antibody isolated by phage display.

Replacement of the hyperimmune anti-Rhesus (Rh) D immunoglobulin, currently used to prevent haemolytic disease of the newborn, by fully recombinant human anti-RhD antibodies would solve the current logistic problems associated with supply and demand. The combination of phage display repertoire cloning with precise selection procedures enables isolation of specific genes that can then be inserted into mammalian expression systems allowing production of large quantities of recombinant human proteins. With the aim of selecting high-affinity anti-RhD antibodies, two human Fab libraries were constructed from a hyperimmune donor. Use of a new phage panning procedure involving bromelin-treated red blood cells enabled the isolation of two high-affinity Fab-expressing phage clones. LD-6-3 and LD-6-33, specific for RhD. These showed a novel reaction pattern by recognizing the D variants D(III), D(IVa), D(IVb), D(Va), D(VI) types I and II. D(VII), Rh33 and DFR. Full-length immunoglobulin molecules were constructed by cloning the variable regions into expression vectors containing genomic DNA encoding the immunoglobulin constant regions. We describe the first, stable, suspension growth-adapted Chinese hamster ovary (CHO) cell line producing a high affinity recombinant human IgG1 anti-RhD antibody adapted to pilot-scale production. Evaluation of the Fc region of this recombinant antibody by either chemiluminescence or antibody-dependent cell cytotoxicity (ADCC) assays demonstrated macrophage activation and lysis of red blood cells by human lymphocytes. A consistent source of recombinant human anti-RhD immunoglobulin produced by CHO cells is expected to meet the stringent safety and regulatory requirements for prophylactic application.

Analysis of the clonal diversity of Staphylococcus aureus methicillin-resistant strains isolated at João Pessoa, state of Paraíba, Brazil

To investigate the clonal diversity of Staphylococcus aureus strains isolated at João Pessoa, State of Paraíba, Brazil, digested genomic DNA were studied by pulsed-field gel electrophoresis (PFGE) in nine methicillin-resistant strains (MRSA) and three methicillin-sensitive strains (MSSA), selected among 67 isolates based on their antimicrobial susceptibility and epidemiology. The isolates were obtained between April and November 1992 from the Hospital of the Federal University of Paraíba, located in João Pessoa. Two MRSA isolates from the Oswaldo Cruz Hospital, São Paulo, Brazil, including an epidemic strain previously detected from different hospitals at the country were used as control. Five different patterns, were demonstrated by MRSA isolated in João Pessoa and these patterns were described in several epidemiologically unrelated hospitals in São Paulo. Our results suggest the interstate dissemination of a MRSA clone in João Pessoa which is similar to that described in other cities of Brazil.