Top PDF La Salut a Barcelona : Salut als districtes i per àrees bàsiques de salut. 2007

With regard to the performance variability of dif- ferent isolates, Sosa Gómez & Alves (1983) verified a high enzymatic activity in more virulent isolates of M. anisopliae from several Brazilian regions, and mentioned that they are probably associated with the presence of en- zymes that influence the penetration process of the fun- gus (St Leger et al., 1988; De La Rosa et al., 1997), as well as with toxins such as destruxins and beauvericin present, respectively, in M. anisopliae and B. bassiana, which vary in different isolates (Roberts & Krasnoff, 1998). Considering that the use of entomopathogenic fungi should be viewed as a component of integrated pest management, the results here obtained suggest that B. bassiana isolate 645 should be used in control programs against the cassava green mite M. tanajoa.

Over the last decades, there have been important changes in the epidemiology of Candida infections. In recent years, Candida species have emerged as important causes of invasive infections mainly among immunocompromised patients. This study analyzed Candida spp. isolates and compared the frequency and biofilm production of different species among the different sources of isolation: blood, urine, vulvovaginal secretions and peritoneal dialysis fluid. Biofilm production was quantified in 327 Candida isolates obtained from patients attended at a Brazilian tertiary public hospital (Botucatu, Sao Paulo). C. albicans ALS3 gene polymorphism was also evaluated by determining the number of repeated motifs in the central domain. Of the 198 total biofilm-positive isolates, 72 and 126 were con- sidered as low and high biofilm producers, respectively. Biofilm production by C. albicans was sig- nificantly lower than that by non-albicans isolates and was most frequently observed in C. tropicalis. Biofilm production was more frequent among bloodstream isolates than other clinical sources,in urine, the isolates displayed a peculiar distribution by presenting two distinct peaks, one containing biofilm-negative isolates and the other containing isolates with intense biofilm production. The num- bers of tandem-repeat copies per allele were not associated with biofilm production, suggesting the evolvement of other genetic determinants.

The outcome of this study is evidence of the fact that Alternaria species can significantly affect the quality of Slovak wheat, which can be reflected in the consumer health. The results show a comparable representation of Alternaria isolates from conventional and new crossbred wheat. In both cases was demonstrated a high isolation frequency (Fr) of isolates from this genus and high relative density (RD) of A. infectoria and A. tenuissima species-groups. High numbers of Alternaria isolates cause concern mainly because of their potential toxigenic properties. Selected strains isolated from samples of conventional and new crossbred wheat (except isolates of A. infectoria species-group) really showed a high ability of mycotoxins production. In addition, Alternaria species deserves attention because currently there are no regulations on Alternaria toxins in food and feed in Europe or in other regions of the world.

The pathogenicity of Candida species is associated with a multitude of virulence factors, including the abil- ity to evade host defences, adhesion to host tissue and/ or medical devices, the ability to form biofilm and the production of tissue-damaging hydrolytic enzymes such as proteases, lipases, and haemolysins (Silva et al. 2012). Along this line of thinking, we demonstrated that the C. nivariensis 893391/INCA strain, the C. nivariensis WM 09.150 reference strain, and the C. glabrata ATCC 2001 type strain were excellent protease producers (Table III), with no significant differences in the Pz values of these strains (p > 0.05). Jang et al. (2011) also found protease activity in six of 38 C. glabrata isolates from fresh feral pigeon faeces, but the production of proteases was mod- erate (mean Pz = 0.65 ± 0.17). Because C. glabrata does not possess classical secreted aspartic protease genes in its genome (Parra-Ortega et al. 2009, Silva et al. 2014), we believe that the enzymatic degradation of albumin verified herein may be due the production of yapsins (YPS). YPS are a family of five nonsecreted glyco- sylphosphatidyinositol (GPI)-linked aspartic proteases in Saccharomyces cerevisiae that have homologues in C. glabrata, which have a well-known role in cell wall integrity (Krysan et al. 2005) and cell-cell interactions (Silva et al. 2014). The role of YPS-family proteases coded by 11 genes is known among the C. glabrata viru- lence factors that have been described. The expression of YPS genes significantly increases the capacity of the fungus to survive inside human macrophages (Krysan et al. 2005). Swoboda-Kopeć et al. (2014) confirmed the prevalence of three genes (YPS2, YPS4, and YPS6) in the majority of C. glabrata strains isolated from clinical specimens. However, the prevalence of these genes in 13 clinical isolates of C. nivariensis was low (Swoboda- Kopeć et al. 2014). Regarding the phytase activity, C. nivariensis 893391/INCA strain and C. nivariensis WM 09.150 reference strain presented a moderate production of phytase, whereas the type strain of C. glabrata exhib- ited a low production of this enzyme (Table III). Phytase is a phosphohydrolase that cleaves phytate and releases inorganic phosphate and inositol, which are both essen- tial nutrients for all living cells (Lei & Porres 2003). In

among the C. albicans strains isolated from oral candidiasis patients when compared to those ones isolated from control individuals. There are few reports in the literature investigating the relationship of virulence in yeast species and sites in the host. In our work, proteinase and phospholipase were detected in 88.1% and 55.9% of C. albicans isolates and in 69.8% and 37.7% of non-albicans Candida, respectively. These results may be attributed to strain characteristics or be related to the site of infection. In blood isolates, independent of species, we found high proteinase activity; in oral cavity the production of this enzyme was higher in C. albicans than in non albicans, while the non-albicans Candida isolates

A Figura 1 apresenta os resultados obtidos pela espectroscopia de absorção na região do infravermelho para os materiais Ka-PUR, Ka-DMSO e Ka-Gli. No espectro da Ka-DMSO podem ser obser[r]

Thirty-four isolates belonging to the collection of the laboratory of Mycology of the department of Microbiology of the Federal University of Minas Gerais were tested. The isolates were obtained from different sources: urine (12), oropharynx (8), blood (4), nail (3) skin (3), hair (1), bronchoalveolar lavage (1), fingers (1) and environment (1). The isolates were previously identified using morphological, physiological and biochemical proofs according with Kurtzman and Fell (4). The tests employed for identification were macroscopic appearance of the giant colony, microscopic features, susceptibility to cycloheximide, growth temperature, diazonium Blue color reaction, urease production and carbohydrate and nitrogen assimilation profiles. Six CBS

Aiming to compare containers usually employed for production of the fungus, as for spore count, an experiment was set up with trays, polypropylene bags and Erlenmeyers. Rectangular aluminum trays (30x44x4.5 cm) were covered with autoclavable plastic bags, whose openings were folded and stapled after 500 g of parboiled rice had been introduced and spread around. In the same way, the polypropylene bags (28x42 cm) were closed with a stapler, after receiving 200 g of parboiled rice, then placed vertically; and the Erlenmeyer flasks, with 2‑L capacity, were sealed with cotton plugs after receiving 250 g of parboiled rice. Rice had been previously moistened with 60% (p/v) of distilled water, left to soak for about two hours and sterilized by autoclaving at 98 kPa, at 120ºC for 25 min. The inoculation of mycelia in the substrates, of the four previously mentioned isolates, took place in a laminar flow chamber. The mycelial mass for inoculation was produced in liquid SDY medium (peptone 10 g L -1 ; dextrose g L -1 ; and yeast extract

The antagonism of eight Bacillus isolates was investigated against nine strains of Xanthomonas campestris pv. campestris (causal agent of crucifers black rot) to assess the role of lipopeptides in this process. Antimicrobial and hemolytic (surfactant) activity tests were performed in vitro using agar diffusion methods. Antibiosis and hemolysis were positive for four Bacillus isolates against all X. campestris pv. campestris strains. The correlation observed between antimicrobial and hemolytic activities indicated that lipopeptides were involved in the antibiosis mechanism of the studied antagonists. Fermentation studies were carried out with the isolates that showed highest antimicrobial and hemolytic activities, to follow up growth and production of bioactive and surfactant compounds. Production of bioactive and surfactant compounds was observed during the late growth phase of the Bacillus isolates.

In Jordan, the frequency of C. sakazakii reported in vacuum dust of a food production facility was 18%, C. sakazakii has also been isolated from food production areas (SHAKER et al. 2007; JANINE, 2015). MÜLLER et al. (2013) showed that C. sakazakii was the most prevalent species identified (93.6%) in a facility processing powdered infant formula in Switzerland. Similarly, MOZROVÁ et al. (2014) reported the organism in samples from a dairy farm and dust from vacuum cleaners in the Czech Republic. For instance, textile filters for exhaust air of spray-drying towers in a milk powder- producing plant were found to be internal reservoirs of C. sakazakii. This situation occurs because of economic reasons, the waste powder from the filters is reintroduced into the product flow for optimization and cost-reduction goals in the production cycle (JACOBS et al., 2011). To lower the contamination risk by C. sakazakii in the production area, air humidity and the number of dust particles in the air should be kept minimal and production equipment should be frequently cleaned and waste powder should be effectively treated (FEI et al., 2015). In this study, 25% of the analyzed dust samples were positive for C. sakazakii. Future studies would discover the impact of the production area and equipment as risk factors on the dissemination of C. sakazakii and create methods to better control this pathogen and reduce its infections.

Recently, several reports have demon- strated that BVDV is highly prevalent in Brazilian cattle (12,16,20), and as such, it is probably associated with significant eco- nomic losses to the national livestock indus- try. These reasons prompted us to initiate epidemiological studies on BVDV infection followed by antigenic and molecular charac- terization of BVDV circulating in Brazilian cattle. Although the production of mAbs to several BVDV isolates has already been re- ported, most of these mAbs have been pro- duced against North American and Euro- pean strains (9,13,14,21). In addition, most of these mAbs were produced against labo- ratory reference strains rather than against field virus isolates. In a recent study, we have demonstrated that the BVDV viruses isolated in Brazil display marked antigenic differences when compared to North Ameri- can reference strains (12,16). We under- stand that the production of mAbs to Brazil- ian BVDV field isolates, antigenically dis- tinct from the standard strains, will help in better defining the antigenic properties of these isolates and in designing more effec- tive diagnostic tools and vaccines.

B. ribis strain EC 01 was positioned at an external branch of the tree (Fig. 2) with genetic similarity of 15% of the B. rhodina isolates group as expected. At the enzyme production levels, B. ribis demonstrated a very distinct pattern from the B. rhodina isolates, showing a basal level of synthesis of the inducible laccases. The levels of the β-1,3-glucanase in the absence of VA was higher than that observed for all of the B. rhodina isolates. The reason for the differences in the production of inducible laccase, as well as β-1,3-glucanase without VA, when compared to the other isolates, have yet to be clarified. In contrast to the laccases and β-1,3-glucanases, the pectinase production profiles did not show any correlation with genetic diversity. No apparent association could be observed between the groups and the levels of pectinase produced. No correlation could be established with the RAPD tree topology and the plant hosts of the fungal strains. According to Zhou and Stanosz (31), host types or their taxonomic relationships are not necessarily indicative of close relationships among different Botryosphaeria species and associated anamorphic fungi. The reason for this observation is still not clear.

IMBL growth inhibition activity. PHEN and MET showed no growth inhibition activity on P. aeruginosa ATCC 27583 at all tested concentrations. On the other hand, EDTA, MPA, and MAC inhibited the bacterial growth of P. aeruginosa ATCC 27583 differently. The IMBL concentrations of 100 mM EDTA, 1.4 mM MPA, 55 mM MET, 1.2 mM MAC, and 8 mM PHEN were chosen to be tested against the 65 genetically unrelated isolates, since they showed the lowest level of inhi- bition of bacterial growth (Table 2). Overall, EDTA, PHEN, and MET presented weak bactericidal activity, with an increase in the size of inhibition zones of 0 to 2 mm. In contrast, MPA produced a larger increase in the size of the inhibition zones, from 0.3 to 12.4 mm (Table 2). Despite increasing the IMBL volumes applied to the blank disks, the mean sizes of the inhibition zones were similar among MBL-producing and non- MBL-producing strains (P ⬍ 0.05), except for MAC at 10 ␮l (P ⫽ 0.05). Therefore, the bactericidal effect of IMBL was not in- fluenced by the production of IMP, VIM, SPM, GIM, or SIM, making no difference to the calculation of SN and SP values. Hydrolysis tests. Hydrolysis test results showed that EDTA and PHEN were not able to hydrolyze the antimicrobial agents tested, while MAC, MET, and MPA demonstrated hydrolytic activity against imipenem but not against ceftazidime (data not shown). The hydrolysis of imipenem, ceftazidime, ampicillin, and aztreonam by MPA has been observed already (14); how- ever, the ability of other IMBLs to hydrolyze ␤-lactam agents has not been seen previously.

The clinical significance of CONS is increasing day by day and there is a need for accurate identification to species level by simple, inexpensive methodology and their antibiotic sensitivity to avoid decreased susceptibility to glycopeptides. Pathogenecity of CONS strains may be decided by screening for biofilm production. CRA method is simple and is very easy to perform and interpret, can be used as screening test for biofilm detection in all conventional microbiology laboratories. Biofilm producing CONS species from healthy controls determine the risk of acquiring more infections in hospitals and pose a major concern. Multidrug resistant nature of MRCONS necessitates every effort to be made to eradicate infections by them through a strict hospital policy.

The prevalence of virulence genes expressing fimbriae, production of hemolysin, colicin and aerobactin, was determined in Escherichia coli isolates from healthy cow’s genital tract not showing clinical signs of infection. The presence of fimbriae expression genes (pap, sfa, afa) was assayed using specific primers in a polymerase chain reaction; none were detected in any of the isolates. Yet, a prevalence of 90.4%, 69.8%, and 28.5% of virulence factors for colicin, hemolysin and aerobactin respectively, was detected in the isolates. Analysis of the bacterial pathogenicity of isolates from the bovine genital tract may contribute towards the understanding of E. coli behavior.

The effect of enrichment of sawdust with the agricultural waste such as cereal bran on the cultivation of mushroom has been the subject of several studies. These works aimed to enhance the substrate with low-cost nutrients and to reduce the waste, thereby minimizing the pollution, and generating the products of commercial interest. Poor mycelial growth on the substrates enriched with SB could be attributed to the absence of one or more nutritional compounds in the soybean bran required for the fungal growth, or to the presence of substance that inhibited the fungal growth. Low fructification by the isolate UFV11 (Table 3) could be result of maintaining this fungus under the laboratory conditions. Mycelial transference over long periods of time can cause physiological and/ or morphological changes in the fungus (Maekawa et al., 1988). The isolates UFV52 and UFV63 were recently re-isolated from the basidiocarps, and this practice should guarantee fructification properties. It could be concluded that the vegetative mycelial growth on a sawdust-based medium was clearly dependent on the isolate. Ohga (1992) reported that the incubation time, tree species of the sawdust, concentration and composition of the nutritional supplements, water content, rate of gas exchange, and the isolate significantly influenced the mushrooms production.

Abstract: The simple crossing of different poplar species enables a relatively easy method of obtaining the new cultivars and clones by artificial selection, combined with production cha[r]

A TEM-β-lactamase is a narrow-spectrum beta-lactamase gene, which confers resistance against penicillin’s and first-generation cephalosporins [23]. In this study, bla TEM being detected in 7 isolates out of 17 enterobacteria-producing beta-lactamase as a sole mechanism of resistance to beta-lactams and all these isolates showed an ampicillin, cephalothin and or cefu- roxime resistance phenotypes. TEM-β-lactamase has been previously detected in fecal isolates from mag- pies and wild rabbits from West Wales [24], free-living Canada geese in Georgia and North Carolina [19], wild animals in Portugal [20], Zoo animals in Japan [21], black-headed gulls in the Czech Republic [4], yel- low-legged gulls in France [5], imported flamingos in Japan [25], gulls population in Sweden [12], migra- tory and resident population of rooks in Austria [26], seagulls and crows in Bangladesh [27].

Numerous molecular typing methods are available but each has specific limitations due to either high cost (labor and expertise) and or a narrow range of discrimination within F. tularensis subspecies and principle populations. Molecular typing methods such as pulsed-field gel electrophoresis (PFGE), amplified fragment length polymorphism (AFLP) [22], RD1 [23], and multi-locus variable- number tandem repeat (VNTR) analysis (MLVA) [24] have been shown to be highly effective at F. tularensis species and subspecies differentiation [1]. However, these molecular methods are expensive, labor intensive, and often require extensive experience to perform [1], making them ill-suited for clinical diagnostics. Simple presence/absence PCR-based assays are effective at confirming F. tularensis from clinical [25–28] or environmental samples [14,29–32] and can be highly sensitive when a TaqMan fluorogenic real-time PCR platform is used [29,32–36], but they cannot further differentiate among the subspecies or subpopula- tions nor can they differentiate a negative result from a PCR failure. Other PCR assays do provide genetic differentiation at varying resolution [37,38], some between F. tularensis subspecies tularensis and holarctica [33,34,39,40] and another includes mediasiatica [41]. Other assays are capable of differentiating subpopulations of F. tularensis subsp. tularensis subpopulations A.I and A.II [16,42]. Several studies have presented SYBR green based real-time PCR assays that differentiate numerous genetic groups within F. tularensis [19,43,44]. However, due to the mild inhibitory properties of SYBR green [45], these assays are not typically highly sensitive to samples containing low level DNA amounts or trace PCR inhibitors, which are typical of environ- mental and clinical samples [46]. Although SYBR assays are ill- suited for environmental and clinical samples, Dual Probe TaqMan real-time PCR assays have been successfully used on such samples due to their sensitivity to low level DNA amounts [16,47] and tolerance for the trace amounts of PCR inhibitors. However, there is no simple assay or set of assays available, in the form of highly sensitive TaqMan real-time PCR assays, that are capable of distinguishing the species F. tularensis and then further differentiating F. tularensis isolates into all of the known subspecies and principle subpopulations. Such differentiation is highly desirable given the differences in virulence and geographic distributions among these major genetic groups [1,48]. Obtaining this information would be a necessary first step in any epidemiological or forensic investigation involving F. tularensis, which would likely involve environmental or clinical samples.

A small fragment of A. flavus colony in SDA at 25°C was inoculated on the center of a Petri dish with Coconut Agar (21). Incubation was carried out at 25°C for 10 days, and the cultures were assayed for aflatoxins as describe by Lin and Dianese (21). The Coconut Agar cultures were extracted with chloroform (30 ml chloroform per 10g culture) by shaking for 30 minutes. The content was filtered through a Whatman #1 filter paper and evaporated to dryness. The suspended extracts were quantified by thin-layer chromatography (TLC) using standard aflatoxins (Sigma) (1).