Effects of Meloidogyne spp. and Rhizoctonia solani on the Growth of Grapevine Rootings

A disease complex involving Meloidogyne incognita and Rhizoctonia solani was associated with stunting of grapevines in a field nursery. Nematode reproduction was occurring on both susceptible and resistant cultivars, and pot experiments were conducted to determine the virulence of this M. incognita population, and of M. javanica and M. hapla populations, to V. vinifera cv. Colombard (susceptible) and to V. champinii cv. Ramsey (regarded locally as highly resistant). The virulence of R. solani isolates obtained from roots of diseased grapevines also was determined both alone and in combination with M. incognita. Ramsey was susceptible to M. incognita (reproduction ratio 9.8 to 18.4 in a shadehouse and heated glasshouse, respectively) but was resistant to M. javanica and M. hapla. Colombard was susceptible to M. incognita (reproduction ratio 24.3 and 41.3, respectively) and M. javanica. Shoot growth was suppressed (by 35%) by M. incognita and, to a lesser extent, by M. hapla. Colombard roots were more severely galled than Ramsey roots by all three species, and nematode reproduction was higher on Colombard. Isolates of R. solani assigned to putative anastomosis groups 2-1 and 4, and an unidentified isolate, colonized and induced rotting of grapevine roots. Ramsey was more susceptible to root rotting than Colombard. Shoot growth was inhibited by up to 15% by several AG 4 isolates and by 20% by the AG 2-1 isolate. AG 4 isolates varied in their virulence. Root rotting was higher when grapevines were inoculated with both M. incognita and R. solani and was highest when nematode inoculation preceded the fungus. Shoot weights were lower when vines were inoculated with the nematode 13 days before the fungus compared with inoculation with both the nematode and the fungus on the same day. It was concluded that both the M. incognita population and some R. solani isolates were virulent against both Colombard and Ramsey, and that measures to prevent spread in nursery stock were therefore important.     

Expression profiles of genes involved in starch synthesis in non-waxy and waxy wheat

Non-waxy and waxy types of wheat were used to study the expression profiles of genes involved in starch synthesis. During grain development, expression profiles and levels of AGPL and AGPS genes were similar to each other. SSI expression remained constant during the late grain development, while expression of SSII and SSIII was higher over the early to middle and middle grain development, and the GBSSI was actively expressed during the entire grain development. SBEIIa was higher expressed during early to middle stage, SBEIIb was active in middle and SBEI during middle to late grain development. During the entire grain development, expression levels of GBSSI and SSIII genes were higher in non-waxy type of wheat, while those of SBEI and SBEIIb were lower in the non-waxy type of wheat. Expression of all genes involved in starch synthesis was stage-specific and tissue-specific. In addition, the expression profiles of genes encoding starch synthase were in agreement with the activity changes of starch synthase during grain development.     

Aerosols as a Source of Widespread Mycoplasma Contamination of Tissue Cultures

Mycoplasma isolates were cultured from 15 antibiotic-free cell cultures obtained from a single laboratory. Complement-fixation tests showed that these isolates were antigenically related to each other but were unrelated to M. hominis type 1, M. hominis type 2, M. arthritidis, M. laidlawii type B, Mycoplasma sp. H.Ep. #2 (Barile), or M. salivarium. Examination of serum used to feed the infected cell lines revealed no Mycoplasma. Infection resulting from cross-contamination by a single Mycoplasma strain from one cell culture to another was investigated. Although the organisms were not found in the air over the work area, aerosols containing these contaminants were produced in tissue culture bottles during the trypsinization of cell monolayers. The minimal infectious dose of Mycoplasma for tissue cultures was measured, and it was determined that one organism was capable of initiating an infection in a tissue culture. The pattern of contamination and the small dose required for infection indicated that Mycoplasma contamination was spread from one tissue culture to another via aerosols. It was demonstrated that Mycoplasma can be transferred from one cell culture to another through the use of a common burette for dispensing medium.     

Eimeria acervulina, E. brunetti, and E. maxima: pathogenic effects of single or mixed infections with low doses of oocysts in chickens.

The pathogenic effects of E. acervulina, E. brunetti, and E. maxima were modified when chickens received mixed infections with these species.Six-week-old chickens were inoculated with doses of 20,000 oocysts of E. acervulina, 1250 oocysts of E. brunetti, and 5000 oocysts of E. maxima given as a single or mixed infection.Typical signs of coccidiosis were apparent in chickens infected with a single Eimeria sp. When birds were given infections composed of two species, the weight loss was greater than that due to either given alone but when three species were given, weight loss was slightly less than that due to infection will E. brunetti alone. Oocyst production due to E. acervulina tended to be similar in birds given this species alone or with E. brunetti. Output fell to less than 50% when E. acervulina was administered with E. maxima. Oocyst production due to E. brunetti and E. maxima decreased when these species were inoculated together and when they were administered with E. acervulina. Lesions of E. acervulina and E. brunetti were superimposed on those of E. maxima in birds given mixed infections.Growth retardation was not evident in chickens inoculated with E. acervulina alone, although weight loss increased when this species was administered with either E. brunetti or E. maxima.     

骨顶鸡等游禽对不同人为干扰方式的响应

分别于2008年4月至6月和2009 年4月至6月, 采用目标动物取样法在黑龙江省安邦河湿地和大庆龙凤湿地研究了骨顶鸡等水鸟对人为干扰的行为响应。结果表明:骨顶鸡对行人和机动车辆两种干扰的反应距离类似,但耐受程度有所不同,骨顶鸡对机动车辆干扰的耐受性要好于行人干扰。在以游客等行人干扰为主的安邦河湿地,骨顶鸡以及其他游禽对干扰产生行为反应的比例要高于以机动车辆干扰为主的龙凤湿地,说明相对于行人干扰骨顶鸡对机动车辆更容易耐受;在安邦河湿地,骨顶鸡对划船的反应距离以及反应程度要大于人行走,说明骨顶鸡对于侵入性的干扰更为敏感。此外,对凤头(Podiceps cristatus)、黒颈(Podiceps nigricollis)、小(Tachybaptus ruficollis)、黑水鸡(Gallinula chloropus)、红头潜鸭(Aythya ferina)、赤膀鸭(Anas strepera)、绿头鸭(Anas platyrhynchos)、斑嘴鸭(Anas poecilorhyncha)、绿翅鸭(Anas crecca)、白眉鸭(Anas querquedula)、赤颈鸭(Anas penelope)、琵嘴鸭(Anas clypeata)等游禽对人为干扰的反应距离、耐受距离以及遭受干扰时的反应比例进行了研究,结果显示3种对干扰的耐受距离差异不显著,12种鸭类中红头潜鸭对人为干扰的敏感性要小于其他鸭类,斑嘴鸭和绿头鸭则相对敏感。     

Biological consequences of ice rafting in a New England salt marsh community

Ice rafting of salt marsh peat is a recurrent phenomenon in north temperate regions. This process was simulated in a northern New England salt marsh to test several hypotheses concerning the effects of peat transport from high to low intertidal heights on the growth and mortality of key sessile organisms: the ribbed mussel Geukensia demissa (Dillwyn), the fucoid alga Fucus vesiculosus L. var. spiralis (Farlow) and the cordgrass Spartina alterniflora (Loisel.). Growth rates increased when Geukensia and Fucus were transported to the lower intertidal; however, Spartina died when similarly transported. Predation pressure (primarily from Carcinus maenus L.) on Geukensia was greater when it was rafted to the lower intertidal zone than in the upper intertidal habitat and was size specific; mussels >3.5cm reached a size-escape from crab predation.A winter survey of dislodged mussels revealed that 72% of the mussels collected were dead and 86% had been overgrown by large Fucus plants, >2.5 × the natural frequency of Fucus overgrowth (32%). In marsh habitats where hard substratum is rare, 91% of the Fucus were growing on Geukensia. A dislodgement experiment showed that a significantly greater percentage of Geukensia was dislodged after ice-out when Fucus was attached to the shell than those mussels without Fucus overgrowth. In the spring, a population survey conducted in the salt marsh examined densities, biomass and population structure of Geukensia, as well as densities, percent cover and biomass of Fucus. Values obtained in the foremarsh were compared to those from the peat islands recently rafted to the tidal flats. Both biomass and densities of Geukensia were similar in the two areas; however, the size-frequency distributions of the mussels were different. Since fewer large mussels, Fucus and Fucus-overgrown mussels were found on the newly transported peat islands, this pattern appears to reflect dislodgement of larger Geukensia by attached algae during ice transport. Two ice-related sources of mortality were identified for Geukensia: (1) Fucus overgrowth acted as a vector for mussel dislodgement and was an indirect source of mortality; and (2) ice crushing was a direct source of mortality for non-overgrown mussels.     

Occurrence of Staphylococcus aureus and evaluation of anti-staphylococcal activity of Lactococcus lactis subsp. lactis in ready-to-eat poultry meat

A total of 181 ready-to-eat poultry meat samples were examined for the presence of Staphylococcus aureus, and 11 (6 %) were found to have S. aureus contamination. Of 11 S. aureus isolates, 10 (91 %) were resistant to at least one antibiotic used in this study, and 2 were resistant to oxacillin. Lactococcus lactis subsp. lactis was tested as a bio-control agent. All the S. aureus isolates were found to be sensitive to antimicrobial products in L. lactis subsp. lactis supernatants; the zones of inhibition were in the range of 5.0 mm?±?0.70 mm to 19.8 mm?±?0.83 mm with the majority of isolates. As a competitive flora in mixed culture (LAPTg broth) and protective culture in poultry meat, L. lactis subsp. lactis was effective against S. aureus isolates; the growth of S. aureus isolates was almost negative after 32 h incubation in mixed culture. The population of S. aureus was reduced substantially to almost log 1 CFU/g after 25 days of incubation in protective culture. The pH of the test cultures also decreased sharply with time.     

Identification ofStreptomyces sp. Tc022, an endophyte inAlpinia galanga, and the isolation of actinomycin D

Some endophytic actinomycetes (120) were isolated from the roots ofAlpinia galanga. Identification of these endophytes was based on their morphology and amino acid composition of the whole-cell extract. Most isolates were classified aStreptomyces sp. (82), with the remainder belonging toNocardia sp. (11),Microbispora sp. (3) andMicromonospora sp. (2). Eight isolates were unclassified and 14 were lost during subculture. The strain identified as endophyticStreptomyces sp. Tc022 strongly inhibitedColletotrichum musae andCandida albicans. This endophyte was cultured, the agar was extracted with organic solvent and the extract was purified on a column of silica gel to give a major component, which was identified to be actinomycin D on the basis of spectroscopic dat Actinomycin D showed antifungal activity againstColletotrichum musae andCandida albicans with the MIC of 10 and 20 mg ml^?1, respectively.     

Ixodid Tick Infestation in Cattle and Wild Animals in Maswa and Iringa,Tanzania

Ticks and tick-borne diseases are important in human and livestock health worldwide. In November 2012, ixodid ticks were collected and identified morphologically from cattle and wild animals in the Maswa district and Iringa urban, Tanzania. Amblyomma gemma, A. lepidum, and A. variegatum were identified from Maswa cattle, and A. variegatum was the predominant species. A. marmoreum, Hyalomma impeltatum, and Rhipicephalus pulchellus were identified from Iringa cattle in addition to the above 3 Amblyomma species, and A. gemma was the most abundant species. Total 4 Amblyomma and 6 Rhipicephalus species were identified from wild animals of the 2 areas. A. lepidum was predominant in Maswa buffaloes, whereas A. gemma was predominant in Iringa buffaloes. Overall, A. variegatum in cattle was predominant in the Maswa district and A. gemma was predominant in Iringa, Tanzania.     

Effect of starvation on the distribution of positional isomers and enantiomers of triacylglycerol in the diatom Phaeodactylum tricornutum

The diatom Phaeodactylum tricornutum was cultivated in a standard medium and under sulfur, silicon, nitrogen and phosphorus starvation and its triacylglycerols (TAGs) were analyzed by RP-HPLC/MS-APCI. Nearly 100 molecular species of polyunsaturated TAGs were identified. RP-HPLC was used to isolate positional isomers of TAGs, which were further separated by chiral HPLC. First eluted were those TAGs that have an eicosapentaenoic acid moiety in the sn-1 position. The ratios of symmetrical to asymmetrical TAGs in P. tricornutum were affected under sulfur-, nitrogen-, phosphorus- and silica-starvation, i.e. in cultivations involving cells in nutrient stress. The ratios of positional TAGs and also the proportions of enantiomers were changed. The ratios of symmetrical to asymmetrical TAGs in the control and under N- and P-starvation were very close. In the control, the ratio of 1,2-dipalmitoyl-3-eicosapentaenoyl-rac-glycerol to 1,3-dipalmitoyl-2-eicosapentaenoyl-rac-glycerol was 3:1 and the ratio of 1,2-dieicosapentaenoyl-3-palmitoyl-rac-glycerol to 1,3-dieicosapentaenoyl-2-palmitoyl-rac-glycerol was 9:1. Under N-starvation the ratios were reversed irrespective of the presence or absence of silicate in the medium. A similar pattern was found in P- and S-starvation.     

Prevalence of Clostridium difficile in raw cow,sheep, and goat meat in Jazan,Saudi Arabia

Background:Clostridium difficile has been shown to be a nosocomial infection associated with diarrhoea and pseudomembranous colitis in hospitalized patients especially old patients. In my previous studies, it was shown the occurrence of C. difficile in animals feces and vegetables which may act as a source of infection to humans.The aim of the study was to determine the prevalence of C. difficile in retail raw cow, sheep, and goat, meat in Jazan, Saudi Arabia.Method: A total of 600 raw meat samples from cow, sheep, and goat were collected during June–December 2015, and tested for the presence of C. difficile. The method used to check for the presence of C. difficile was by choosing selective enrichment media in C. difficile broth, followed by alcohol shock-treatment and plating onto C. difficile selective medium. C. difficile isolates were typed using PCR ribotyping and also analyzed for antibiotic susceptibility.Results: It was shown that, 9 of 600 meat samples (1.5%) were contaminated with C. difficile. The prevalence of C. difficile was as follow: 7 out of 600 (1.17%) were found in cow, 2 out of 600 (0.3%) were found in sheep, while was no C. difficile was isolated from goat. Eleven out of 18 C. difficile isolates were positive for tcdA, tcdB and cdtB toxin genes and were classified as ribotype 078. Three strains were positive tcdA, and tcdB, and two strains possessed only tcdB. C. difficile strains showed high resistance to ampicillin, gentamycin, erythromycin and nalidixic acid.Conclusions: The present work shows the potential risk of raw meet in transmitting C. difficile to humans.     

Persistence of Vancomycin-Resistant Enterococci in New Zealand Broilers after Discontinuation of Avoparcin Use

Large amounts of tylosin, zinc-bacitracin, and avilamycin are currently used as prophylactics in New Zealand broiler production. Avoparcin was also used from 1977 to 2000. A total of 382 enterococci were isolated from 213 fecal samples (147 individual poultry farms) using enrichment broths plated on m-Enterococcus agar lacking antimicrobials. These isolates were then examined to determine the prevalence of antimicrobial resistance. Of the 382 isolates, 5.8% (22 isolates) were resistant to vancomycin, and 64.7% were resistant to erythromycin. The bacitracin MIC was ≥256 μg/ml for 98.7% of isolates, and the avilamycin MIC was ≥8 μg/ml for 14.9% of isolates. No resistance to ampicillin or gentamicin was detected. Of the 22 vancomycin-resistant enterococci (VRE) isolates, 18 (81.8%) were Enterococcus faecalis, 3 were Enterococcus faecium, and 1 was Enterococcus durans. However, when the 213 fecal enrichment broths were plated on m-Enterococcus agar containing vancomycin, 86 VRE were recovered; 66% of these isolates were E. faecium and the remainder were E. faecalis. Vancomycin-resistant E. faecium isolates were found to have heterogenous pulsed-field gel electrophoresis (PFGE) patterns of SmaI-digested DNA, whereas the PFGE patterns of vancomycin-resistant E. faecalis isolates were identical or closely related, suggesting that this VRE clone is widespread throughout New Zealand. These data demonstrate that vancomycin-resistant E. faecalis persists in the absence and presence of vancomycin-selective pressure, thus explaining the dominance of this VRE clone even in the absence of avoparcin.     

Evaluation of the prevalence of enterotoxigenic Bacteroides fragilis and the distribution bft gene subtypes in patients with diarrhea

The aim of this study was to determine the prevalence of enterotoxigenic Bacteroides fragilis (ETBF) in the patients with diarrhea in our region and to assess the association between diarrhea and bft gene subtypes. The presence of ETBF and bft gene subtypes were investigated in 200 stool samples from patients with diarrhea, diagnosed as gastroenteritis, which were sent to Clinical Microbiology Laboratory at Zonguldak Karaelmas University, Training and Research Hospital and in 200 stool samples from age-matched healthy subjects between April 14, 2009 and October 28, 2009. Nested – polymerase chain reaction was used to detect the presence of bft gene directly from stool samples. The bft gene subtypes were determined by PCR in case of ETBF detection. The presence of bft gene was detected in 29 (15%) of patients and 27 (14%) of control group. bft-1 and bft-2 were found in 24 and five stool samples from 29 diarrheic patients with ETBF, respectively. Among 27 control patients with ETBF, bft-1 and bft-2 were found in 24 and three samples, respectively. No bft-3 subtypes were identified in our study. ETBF was found as a single pathogen in 9% of the patients with diarrhea, while there was an accompanying pathogen in 6% of the patients. The proportion of coinfection with another pathogen among ETBF positive patients was 38%. Cooccurance with ETBF was present in nine of 18 patients with Rotavirus and two of five patients with Entamoeba histolytica. In conclusion; there was no statistically significant difference between the prevalence of ETBF in diarrheal patients and that of the control group. When the patients and controls were compared for each age group, no statistically significant difference in ETBF rates was found. There was no significant difference between groups with respect to bft subtypes; bft-1 was identified as the most common subtype. The rate of coinfection of ETBF and Rotavirus was high.     

Fungemia in hospitals of the City of Buenos Aires, Argentina

BackgroundThe incidence of fungi like pathogens in hospitals varies by regions.ObjectivesOur goal was not only to record the incidence and etiology of fungaemia, but also the change during the 4 years analysed, to determine the time of detection in automated blood culture and by lysis-centrifugation, and finally to assess the gender, age and underlying disease of the patients with fungaemia.MethodsAn observational multicentre study of fungaemia was conducted in hospitals in the Mycology Network of Buenos Aires.ResultsA total of 190,920 blood cultures were processed: 182,050 automated blood culture and 8,870 lysis-centrifugation. Fungi were recovered in 1,020 episodes. The overall incidence of fungaemia was 1.72/1,000 admissions; 683 episodes were due to Candida (68%), and 325 (32%) to other fungi: 214 Cryptococcus, 105 Histoplasma, 7 Rhodotorula, 5 Trichosporon, 2 Pichia, 2 Acremonium, one Saccharomyces and one Fusarium. The incidence of candidaemia was 1.15/1,000 admissions with a wide variation between centres (0.35 to 2.65). Most Candida isolates (97%) were detected in the first 2 days of incubation. Candida albicans was recovered in 43% of the episodes. In fungaemia other than candidaemia, the predominant fungi were Cryptococcus and Histoplasma capsulatum.ConclusionsThe incidence remained stable during the study period. Fungaemia by Candida were predominant. C. albicans was involved in less than a half of the episodes. The recovery of Cryptoccocus and H. capsulatum is strongly associated with HIV patients.     

Binding-site specificity of lectins from Bauhinia purpurea alba,Sophora japonica,and Wistaria floribunda

The binding-site specificities of lectins isolated from the seeds of Baihinia purpurea alba, Sophora japonica, and Wistaria floribunda were studied by hemagglutination-inhibition assays utilizing a variety of saccharides as inhibitors. For Bauhinia lectin, 2-acetamido-2-deoxy-d-galactose was found to be the best monosaccharide inhibitor and the free monosaccharide inhibitor was as active as its glycosides. d-Galactose was a weak inhibitor and so were some of its glycosides. Some of the oligosaccharides having a d-galactose nonreducing terminus were good inhibitors, but substitution on the d-galactose or 2-acetamido-2-deoxy-d-galactose residues with other saccharides abolished the inhibitory activity. No specificity for anomeric configuration or linkage position could be demonstrated. The presence of aromatic aglycon groups did not enhance inhibitory activity of the saccharides tested and, in some cases, the inhibitory activity was decreased. In contrast to the results for the Bauhinia lectin, compounds having aromatic aglycon groups were markedly better inhibitors for Sophora and Wistaria lectins than the corresponding compounds without aromatic aglycons. d-Galactose was a weak inhibitor for Sophora and Wistaria lectins, whereas 2-acetamido-d-galactose was a poor inhibitor of Sophora lectin but a good inhibitor of Wistaria lectin. Sophora and Wistaria lectins were somewhat similar in their activity as some of the saccharides having a d-galactose in penultimate position to an l-fucose residue were weak inhibitors. However, Sophora lectin has a binding preference for β anomers, whereas Wistaria lectin did not demonstrate a clear preference for α or β anomers. For some pairs of compounds, the α was a better inhibitor than, the β anomer; in other cases, the reverse was true.     

Habitat associations of opossums and rodents in a lowland forest in French Guiana

Opossums and rodents were sampled by live-trapping at Paracou, French Guiana to study habitat use. Tomahawk and Sherman traps were placed on the ground and at various heights in the subcanopy and canopy. We captured 10 species of opossums and seven species of rodents. We measured 14 microhabitat variables at each of 485 sampling stations. Presence or absence at a trap station of the three most abundant species of opossums (Didelphis albiventris, Didelphis marsupialis, and Micoureus demerarae) and two rodents (Oecomys rutilus and Proechimys cuvieri) were related by logistic regression analysis to the microhabitat variables. All five species were associated with at least one habitat variable. Linear analysis of categorical data was used to determine the degree of arboreality. Didelphis marsupialis and P. cuvieri were more commonly captured on the ground, D. albiventris was equitably distributed between ground and arboreal traps, and the remaining species were mostly arboreal. Linear analysis was used to compare the distribution of arboreal captures among two substrate types, two heights, and two substrate diameters. Oecomys rutilus was more commonly captured on lianas, D. albiventris and O. rutilus were more commonly captured at lower heights, and D. marsupialis demonstrated a preference for larger arboreal substrates.     

Evaluation of different bovine muscles to be applied in freeze-drying for instant meal. Study of physicochemical and senescence parameters

The aim of the present research was to evaluate bovine muscles to be subjected to freeze-drying for an instant meal. Physicochemical and senescence parameters were evaluated. The experimental part was divided into two steps. In the first step, the Semitendinosus muscle was chosen to establish methodology and experimental conditions. Physicochemical, microstructure and senescence parameters were analysed. In the second step, economic bovine muscles such as Semimembranous and Spinalis dorsi were subjected to the same methodology and conditions as in the first step in order to compare them by analysing the same parameters. L* and a* values were statistically significant (P<0.05) for Semimembranous and Spinalis dorsi muscles, showing differences among condition effects and in muscles. Humidity and water activity showed among the muscles analysed that cooked and rehydrated samples did not exhibit differences. Microstructure of Semitendinosus and Semimembranous were not separated and fragmented as occurred with Spinalis dorsi after freeze-drying. Results allowed us to select among the muscles studied that Semimembranous was suitable and economic to be used in an instant meal.     

Effect of Meloidogyne incognita on Reproduction of Pratylenchus penetrans in Red Clover and Alfalfa

Roots of seedlings of red clover and alfalfa growing on 10⁻¹ Hoagland and Arnon solution agar were inoculated with various combinations of Meloidogyne incognita and Pratylenchus penetrans. Egg-laying by P. penetrans decreased as the number of nematodes, the ratio of entrant M. incognita to entrant P. penetrans, and the priority of invasion of roots by M. incognita increased. Embryogeny and hatching of eggs of P. penetrans, and development of larvae of M. incognita, were not affected. In red clover, the greatest red uction occurred when there were 65 entrant nematodes, the ratio of M. incognita:P. penetrans was 4:1 and M. incognita was inoculated four days prior to P. penetrans. In alfalfa, the less-favorable host for both nematodes, the greatest reduction occurred when there were 45 entrant nematodes, the ratio of M. incognita:P. penetrans was 2:1, and M. incognita was inoculated 4 days prior to P. penetrans.