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Cultural Methods (cultural + methods)
Selected AbstractsStrategies for controlling cassava mosaic virus disease in AfricaPLANT PATHOLOGY, Issue 5 2005J. M. Thresh Cassava mosaic disease (CMD) is caused by whiteflyborne viruses of the genus Begomovirus (family Geminiviridae). The disease has long been regarded as the most important of those affecting cassava in sub-Saharan Africa, and has been the subject of much research, especially since the onset of the current very damaging pandemic in eastern and central Africa. This review considers the main features of CMD and the various possible means of control. The main emphasis to date has been on the development and deployment of virus-resistant varieties. These are widely adopted in countries where CMD has caused serious problems, and provided a powerful incentive for farmers to abandon some of the most susceptible of their traditional varieties. Only limited use has been made of phytosanitation involving CMD-free planting material and the removal (roguing) of diseased plants. Cultural methods of control using varietal mixtures, intercrops or other cropping practices have also been neglected, and there is a need for much additional research before they can be deployed effectively. Nevertheless, the severe losses now being caused by CMD in many parts of sub-Saharan Africa could be greatly decreased through the application of existing knowledge. [source] INCIDENCE OF LISTERIA SPECIES IN SEAFOOD PRODUCTS OF MYSORE, INDIAJOURNAL OF FOOD SAFETY, Issue 4 2007AHMED SAIF MOHAREM ABSTRACT Listeria monocytogenes is one of the most important foodborne pathogens causing illness in humans and animals. Thus, a study was undertaken to investigate the incidence of Listeria species in fresh and dry fish samples marketed in Mysore, India. A total of 164 fresh and dry fish samples collected from retail outlet shops of Mysore, South India, during the period August 2005 through August 2006 were examined for the presence of Listeria species by using ISO 11290 protocol. The incidence of Listeria species was positive in 62 samples (37.8%), and L. monocytogenes was isolated from only three (1.83%) fresh fish samples. Listeria species in seafood were predominant in the order of Listeria innocua (50) (30.49%), Listeria grayi (eight) (4.9%), L. monocytogenes (three) (1.83%) and Listeria seeligeri (one) (0.6%). All isolates of Listeria species were subjected to polymerase chain reaction (PCR) and confirmed with the genus-specific set of primers, and special emphasis was given for detection of L. monocytogenes using a species-specific set of primers. The specificity and sensitivity of PCR were in good correlation with the cultural methods. The results indicated a high incidence of Listeria species and L. monocytogenes in fresh fish samples. This warrants the need for appropriate control measures as this would pose a serious threat to human health. [source] Prevalence of Campylobacter spp. in a subset of intensive poultry flocks in IrelandLETTERS IN APPLIED MICROBIOLOGY, Issue 3 2009A. Patriarchi Abstract Aim:, The aim of this study was to investigate the prevalence of Campylobacter species in a subset of intensive poultry flocks by examining samples collected in geographically disparate areas on the island of Ireland. Methods and Results:, Faecal, water and environmental samples were collected from the interior of poultry houses on nine farms. Three cultural methods were used for Campylobacter isolation: direct plating, enrichment culture and a recovery method for emerging Campylobacter spp. Presumptive Campylobacter isolates were confirmed using biochemical tests and further identified to species level by multiplex PCR. All flocks sampled in this study were found to be contaminated with Campylobacter at the time of sampling. Structural and air samples taken from the interior of broiler houses were also found to be Campylobacter positive. All water samples were found to be Campylobacter negative. The Campycheck method was used for the isolation of emerging Campylobacter spp. Conclusions:,Campylobacter spp. were recovered (as contaminants) from the poultry house interior, air and environmental samples in all intensive poultry flocks surveyed. Significance and Impact of the Study:, This study highlights the need for improved biosecurity on selected poultry farms. [source] Zirconium hydroxide effectively immobilizes and concentrates human enteric virusesLETTERS IN APPLIED MICROBIOLOGY, Issue 5 2002D.H. D'Souza Background: Detection of human enteric viruses in foods and environmental samples requires concentration of viruses from complex matrices before application of molecular or cultural methods. Previous studies have described the use of zirconium hydroxide to concentrate bacteria from clinical, environmental, and food samples. Aims: Our study describes the application of zirconium hydroxide to concentrate human enteric viruses. Methods: Poliovirus type 1, hepatitis A virus (HAV) strain HM-175, and Norwalk virus (NV) were used as models. Virus recovery was evaluated both as loss to discarded supernatants and as recovery in the precipitated pellets. Results: Poliovirus type 1, based on the plaque assay recoveries, ranged from 16 to 59% with minimal loss to the supernatant (1,5%). For both HAV and NV, RT-PCR amplicons of appropriate sizes were detected and confirmed in the pellet fraction with no visible amplicons from the supernatant. Significance and Impact of the Study: This rapid and inexpensive method shows promise as an alternative means to concentrate enteric viruses. [source] Identification of Microsporum canis from dermatophytic pseudomycetoma in paraffin-embedded veterinary specimens using a common PCR protocolMYCOSES, Issue 3 2007Simona Nardoni Summary The effectiveness of a simple PCR protocol performed on paraffin-embedded tissues, obtained from histopathologically and culturally diagnosed cases of dermatophytic pseudomycetoma DPM was tested. The specimens were investigated using previously described primers (DH1L and DH1R) targeting the 18S rDNA gene and amplifying a 183-bp fragment. Microsporum canis was identified from all samples. The PCR protocol described in the present work demonstrated a 100% concordant result comparing the molecular characterisation with phenotypic characterisation of dermatophytes. Molecular biology could represent a valid identification tool in dermatophytic deep infections, when diagnosis cannot be achieved by cultural methods. [source] Modulation of primary and secondary infections in epidemics of carrot cavity spot through agronomic management practicesPLANT PATHOLOGY, Issue 1 2008F. Suffert The relative importance of primary and secondary infections (auto- and alloinfections) in the development of a carrot cavity spot (CCS) epidemic caused by Pythium spp. were investigated. Three cropping factors: fungicide application, soil moisture and planting density, were selected as the key variables affecting the disease tetrahedron. Their effects on: (i) disease measurements at a specific time, (ii) the areas under the disease progress curves (AUDPCs) and (iii) a time-dependent parameter in a pathometric incidence-severity relationship, were studied. Mefenoxam applications 5 and 9 weeks after sowing reduced the intensity of a field CCS epidemic that involved both primary and secondary infections. In microcosm experiments, mefenoxam reduced secondary infections by Pythium violae obtained by transplanting infected carrot roots and slowed disease progress (1·6 lesions per root in treated versus 5·8 lesions in non-treated microcosms). A deficit of soil moisture limited the movement of Pythium propagules to host tissue, and thus reduced primary infections in the field; it also promoted the healing of lesions, limiting lesion expansion and the potential for alloinfections (6·8,7·5 lesions per root in irrigated plots compared with 2·4 lesions in non-irrigated plots). A negative relationship between the mean root-to-root distance and the rate of alloinfections was established in microcosms; a reduction in mean planting density was also effective in limiting CCS development (0·5, 1·6 and 2·0 lesions per root in microcosms containing 8, 16 and 31 roots, respectively). An integrated disease management system based on a combination of cultural methods, such as optimized fungicide application, date of harvest versus soil moisture content, and host density versus planting pattern, may make a useful contribute to the control of CCS. [source] Microbiologic Diagnostics at Titanium ImplantsCLINICAL IMPLANT DENTISTRY AND RELATED RESEARCH, Issue 4 2003Åsa Leonhardt DDS ABSTRACT Background: The microbiota found at periimplant lesions have been shown to contain putative periodontal pathogens as well as opportunistic species such as Staphylococcus spp, enterics, and Candida spp. Therefore, a microbiologic diagnosis may be of value as guidance before treatment of such lesions. Purpose: The aim of this study was to evaluate the prevalence of some putative pathogens associated with long-term fol-lowed-up cases using two different microbiologic procedures. Malerials and Methods: Fifteen subjects contributed with plaque samples from teeth and implants; these were analyzed with respect to 18 putative periimplant pathogens using cultural methods and a deoxyribonucleic acid DNA-DNA hybridization technique. Results: The number of individuals positive for the analyzed pathogens was similar in samples taken from teeth and implants when analyzed with the DNA-DNA hybridization technique. When comparing detection frequency by culture procedure and by "checkerboard" technique at implants, the number of individuals positive for these species was lower with the traditional culture technique than with the checkerboard analyses. Using a higher cutoff point (4) with the checkerboard technique, the number of positive individuals was generally lower than that found with the culture technique. When comparing the techniques on an implant site level, the prevalence obtained by culture was lower for all analyzed species. If the specific species were present in the samples analyzed by the checkerboard technique, they were present only in every second sample analyzed with the culture technique. The high specificity values showed that if the checkerboard technique did not detect any Porphyromonas gingivalis, Prevotla intermedia, Actinobadllus actinomycetem-comitans, or Fusobacterium nudeatum, the bacteria were also undetectable by the culture technique. The two methods therefore did not overlap but did supplement each other. Conclusions: Based on the current results it is recommended that the technique used when analyzing microbiota around titanium implants should be a combination of the two protocols mentioned as they seem to give the most comprehensive outcome when used together. [source] | |||||||||||||