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Charles Manceau - One of the best experts on this subject based on the ideXlab platform.
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Housekeeping Gene Sequencing and Multilocus Variable-Number Tandem-Repeat Analysis To Identify Subpopulations within Pseudomonas Syringae pv. maculicola and Pseudomonas Syringae pv. tomato That Correlate with Host Specificity
Applied and Environmental Microbiology, 2012Co-Authors: Sophie Gironde, Charles ManceauAbstract:Pseudomonas Syringae pv. maculicola causes bacterial spot on Brassicaceae worldwide, and for the last 10 years severe outbreaks have been reported in the Loire Valley, France. P. Syringae pv. maculicola resembles P. Syringae pv. tomato in that it is also pathogenic for tomato and causes the same types of symptoms. We used a collection of 106 strains of P. Syringae to characterize the relationships between P. Syringae pv. maculicola and related pathovars, paying special attention to P. Syringae pv. tomato. Phylogenetic analysis of gyrB and rpoD gene sequences showed that P. Syringae pv. maculicola, which causes diseases in Brassicaceae, forms six genetic lineages within genomospecies 3 of P. Syringae strains as defined by L. Gardan et al. (Int. J. Syst. Bacteriol. 49[ Pt 2]: 469-478, 1999), whereas P. Syringae pv. tomato forms two distinct genetic lineages. A multilocus variable-number tandem-repeat (VNTR) analysis (MLVA) conducted with eight minisatellite loci confirmed the genetic structure obtained with rpoD and gyrB sequence analyses. These results provide promising tools for fine-scale epidemiological studies on diseases caused by P. Syringae pv. maculicola and P. Syringae pv. tomato. The two pathovars had distinct host ranges; only P. Syringae pv. maculicola strains were pathogenic for Brassicaceae. A subpopulation of P. Syringae pv. maculicola strains that are pathogenic for Pto-expressing tomato plants were shown to lack avrPto1 and avrPtoB or to contain a disrupted avrPtoB homolog. Taking phylogenetic and pathological features into account, our data suggest that the DC3000 strain belongs to P. Syringae pv. maculicola. This study shows that P. Syringae pv. maculicola and P. Syringae pv. tomato appear multiclonal, as they did not diverge from a single common ancestral group within the ancestral P. Syringae genomospecies 3, and suggests that pathovar specificity within P. Syringae may be due to independent genetic events.
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comparison of randomly amplified polymorphic dna with amplified fragment length polymorphism to assess genetic diversity and genetic relatedness within genospecies iii of pseudomonas Syringae
Applied and Environmental Microbiology, 1998Co-Authors: Agathe Clerc, Charles Manceau, Xavier NesmeAbstract:Recently, DNA pairing analyses showed that Pseudomonas Syringae pv. tomato and related pathovars, including P. Syringae pv. maculicola, form a genomic species (Pseudomonas tomato) (L. Gardan, H. L. Shafik, and P. A. D. Grimont, p. 445-448, in K. Rudolph, T. J. Burr, J. W. Mansfield, D. Stead, A. Vivian, and J. von Kietzell, ed., Pseudomonas Syringae Pathovars and Related Pathogens, 1997). The genetic diversity of 23 strains belonging to this genomic species and 4 outgroup strains was analyzed with randomly amplified polymorphic DNA (RAPD) and amplified fragment length polymorphic (AFLP) techniques. Simple boiling of P. Syringae cells was suitable for subsequent DNA amplification to obtain reliable patterns in RAPD and AFLP analyses. In general, the grouping of P. Syringae strains by both analysis techniques corresponded well with the classification obtained from an RFLP analysis of ribosomal DNA operons, DNA pairing studies, and an analysis of pathogenicity data. However, two strains of P. Syringae pv. maculicola produced distinct DNA patterns compared to the DNA patterns of other P. Syringae pv. maculicola strains; these patterns led us to assume that horizontal transfer of DNA could occur between bacterial populations. Both techniques used in this study have high discriminating power because strains of P. Syringae pv. tomato and P. Syringae pv. maculicola which were indistinguishable by other techniques, including pathogenicity tests on tomato, were separated into two groups by both RAPD and AFLP analyses. In addition, data analysis showed that the AFLP method was more efficient for assessing intrapathovar diversity than RAPD analysis and allowed clear delineation between intraspecific and interspecific genetic distances, suggesting that it could be an alternative to DNA pairing studies. However, it was not possible to distinguish the two races of P. Syringae pv. tomato on the basis of an analysis of the data provided by either the AFLP or RAPD technique.
Alex H Kral - One of the best experts on this subject based on the ideXlab platform.
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Higher syringe coverage is associated with lower odds of HIV risk and does not increase unsafe syringe disposal among syringe exchange program clients
Drug and Alcohol Dependence, 2007Co-Authors: Ricky N. Bluthenthal, Neil M. Flynn, Rachel Anderson, Alex H KralAbstract:Abstract Objective To determine if adequate syringe coverage – “one shot for one syringe” – among syringe exchange program (SEP) clients is associated with injection-related HIV risk behaviors and syringe disposal. Design HIV risk assessments with 1577 injection drug users (IDUs) recruited from 24 SEPs in California between 2001 and 2003. Individual syringe coverage was calculated as a proportion of syringes retained from SEP visits to total number of injections in the last 30 days. Results Participants were divided into four groups based on syringe coverage: Conclusions Individual syringe coverage is strongly associated with safer injection behaviors without impacting syringe disposal among SEP clients. Syringe coverage is a useful measure for determining if IDUs are obtaining sufficient syringes to lower HIV risk.
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examination of the association between syringe exchange program sep dispensation policy and sep client level syringe coverage among injection drug users
Addiction, 2007Co-Authors: Neil M. Flynn, Rachel Anderson, Ricky N. Bluthenthal, Alex H Kral, Greg Ridgeway, Terry L SchellAbstract:Aim To determine whether syringe exchange programs' (SEPs) dispensation policy is associated with syringe cover- age among SEP clients. Design Cross-sectional samples of SEPs and their clients. Setting SEPs in California, USA. Participants Twenty-four SEPs and their injection drug using (IDU) clients (n = 1576). Measurements Clients were classified as having adequate syringe coverage if they received at least as many syringes from the SEP as their self- reported injections in the last 30 days. SEPs were classified based on their syringe dispensation policy. Dispensation schemes ranging from least restrictive to most are: unlimited needs-based distribution; unlimited one-for-one exchange plus a few additional syringes; per visit limited one-for-one plus a few additional syringes; unlimited one-for-one exchange; and per visit limited one-for-one exchange. Findings Adequate syringe coverage among SEP clients by dispensation policy is as follows: unlimited needs-based distribution = 61%; unlimited one-for-one plus = 50%; limited one-for-one plus = 41%; unlimited one-for-one = 42%; and limited one-for-one = 26%. In multivariate analysis, adequate syringe coverage was significantly higher for all dispensation policies compared to per visit limited one-for- one exchange. Using propensity scoring methods, we compared syringe coverage by dispensation policies while con- trolling for client-level differences. Providing additional syringes above one-for-one exchange (50% versus 38%, P = 0.009) and unlimited exchange (42% versus 27%, P = 0.05) generally resulted in more clients having adequate syringe coverage compared to one-for-one exchange and per visit limits. Conclusion Providing less restrictive syringe dispensation is associated with increased prevalence of adequate syringe coverage among clients. SEPs should adopt syringe dispensation policies that provide IDUs sufficient syringes to attain adequate syringe coverage.
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the effect of syringe exchange use on high risk injection drug users a cohort study
AIDS, 2000Co-Authors: Ricky N. Bluthenthal, Alex H Kral, Lauren Gee, Elizabeth A Erringer, Brian R EdlinAbstract:OBJECTIVE To determine whether syringe exchange program use is associated with cessation of syringe sharing among high-risk injection drug users. DESIGN AND METHODS Between 1992 and 1996, street-recruited injection drug users were interviewed and received HIV testing and counseling semi-annually, as part of a dynamic cohort study. We examined a cohort of 340 high-risk injection drug users for whom two observations, 6-months apart, were available and who reported syringe sharing at the first interview. Multivariate logistic regression analysis was performed to determine the relationship between syringe exchange program use and cessation of syringe sharing, while controlling for confounding factors. RESULTS At follow-up interview, 60% (204 of 340) reported quitting syringe sharing. High-risk injection drug users who began using the syringe exchange program were more likely to quit sharing syringes [adjusted odds ratio (AOR), 2.68; 95% confidence interval (CI), 1.35-5.33], as were those who continued using the syringe exchange program (AOR,1.98; 95% CI, 1.05-3.75) in comparison with non-syringe exchange program users, while controlling for confounding factors. CONCLUSIONS The initiation and continuation of syringe exchange program use among high-risk injection drug users is independently associated with cessation of syringe sharing. Syringe exchange program use can be an important component in reducing the spread of blood-borne infectious diseases among high-risk injection drug users.
Ricky N. Bluthenthal - One of the best experts on this subject based on the ideXlab platform.
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Higher syringe coverage is associated with lower odds of HIV risk and does not increase unsafe syringe disposal among syringe exchange program clients
Drug and Alcohol Dependence, 2007Co-Authors: Ricky N. Bluthenthal, Neil M. Flynn, Rachel Anderson, Alex H KralAbstract:Abstract Objective To determine if adequate syringe coverage – “one shot for one syringe” – among syringe exchange program (SEP) clients is associated with injection-related HIV risk behaviors and syringe disposal. Design HIV risk assessments with 1577 injection drug users (IDUs) recruited from 24 SEPs in California between 2001 and 2003. Individual syringe coverage was calculated as a proportion of syringes retained from SEP visits to total number of injections in the last 30 days. Results Participants were divided into four groups based on syringe coverage: Conclusions Individual syringe coverage is strongly associated with safer injection behaviors without impacting syringe disposal among SEP clients. Syringe coverage is a useful measure for determining if IDUs are obtaining sufficient syringes to lower HIV risk.
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examination of the association between syringe exchange program sep dispensation policy and sep client level syringe coverage among injection drug users
Addiction, 2007Co-Authors: Neil M. Flynn, Rachel Anderson, Ricky N. Bluthenthal, Alex H Kral, Greg Ridgeway, Terry L SchellAbstract:Aim To determine whether syringe exchange programs' (SEPs) dispensation policy is associated with syringe cover- age among SEP clients. Design Cross-sectional samples of SEPs and their clients. Setting SEPs in California, USA. Participants Twenty-four SEPs and their injection drug using (IDU) clients (n = 1576). Measurements Clients were classified as having adequate syringe coverage if they received at least as many syringes from the SEP as their self- reported injections in the last 30 days. SEPs were classified based on their syringe dispensation policy. Dispensation schemes ranging from least restrictive to most are: unlimited needs-based distribution; unlimited one-for-one exchange plus a few additional syringes; per visit limited one-for-one plus a few additional syringes; unlimited one-for-one exchange; and per visit limited one-for-one exchange. Findings Adequate syringe coverage among SEP clients by dispensation policy is as follows: unlimited needs-based distribution = 61%; unlimited one-for-one plus = 50%; limited one-for-one plus = 41%; unlimited one-for-one = 42%; and limited one-for-one = 26%. In multivariate analysis, adequate syringe coverage was significantly higher for all dispensation policies compared to per visit limited one-for- one exchange. Using propensity scoring methods, we compared syringe coverage by dispensation policies while con- trolling for client-level differences. Providing additional syringes above one-for-one exchange (50% versus 38%, P = 0.009) and unlimited exchange (42% versus 27%, P = 0.05) generally resulted in more clients having adequate syringe coverage compared to one-for-one exchange and per visit limits. Conclusion Providing less restrictive syringe dispensation is associated with increased prevalence of adequate syringe coverage among clients. SEPs should adopt syringe dispensation policies that provide IDUs sufficient syringes to attain adequate syringe coverage.
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the effect of syringe exchange use on high risk injection drug users a cohort study
AIDS, 2000Co-Authors: Ricky N. Bluthenthal, Alex H Kral, Lauren Gee, Elizabeth A Erringer, Brian R EdlinAbstract:OBJECTIVE To determine whether syringe exchange program use is associated with cessation of syringe sharing among high-risk injection drug users. DESIGN AND METHODS Between 1992 and 1996, street-recruited injection drug users were interviewed and received HIV testing and counseling semi-annually, as part of a dynamic cohort study. We examined a cohort of 340 high-risk injection drug users for whom two observations, 6-months apart, were available and who reported syringe sharing at the first interview. Multivariate logistic regression analysis was performed to determine the relationship between syringe exchange program use and cessation of syringe sharing, while controlling for confounding factors. RESULTS At follow-up interview, 60% (204 of 340) reported quitting syringe sharing. High-risk injection drug users who began using the syringe exchange program were more likely to quit sharing syringes [adjusted odds ratio (AOR), 2.68; 95% confidence interval (CI), 1.35-5.33], as were those who continued using the syringe exchange program (AOR,1.98; 95% CI, 1.05-3.75) in comparison with non-syringe exchange program users, while controlling for confounding factors. CONCLUSIONS The initiation and continuation of syringe exchange program use among high-risk injection drug users is independently associated with cessation of syringe sharing. Syringe exchange program use can be an important component in reducing the spread of blood-borne infectious diseases among high-risk injection drug users.
C. Manceau - One of the best experts on this subject based on the ideXlab platform.
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Origin of the Outbreak in France of Pseudomonas Syringae pv. actinidiae Biovar 3, the Causal Agent of Bacterial Canker of Kiwifruit, Revealed by a Multilocus Variable-Number Tandem-Repeat Analysis
Applied and Environmental Microbiology, 2015Co-Authors: Amandine Cunty, Sophie Cesbron, F. Poliakoff, Marie Agnes Jacques, C. ManceauAbstract:The first outbreaks of bacterial canker of kiwifruit caused by Pseudomonas Syringae pv. actinidiae biovar 3 were detected in France in 2010. P. Syringae pv. actinidiae causes leaf spots, dieback, and canker that sometimes lead to the death of the vine. P. Syringae pv. actinidifoliorum, which is pathogenic on kiwi as well, causes only leaf spots. In order to conduct an epidemiological study to track the spread of the epidemics of these two pathogens in France, we developed a multilocus variable-number tandem-repeat (VNTR) analysis (MLVA). MLVA was conducted on 340 strains of P. Syringae pv. actinidiae biovar 3 isolated in Chile, China, France, Italy, and New Zealand and on 39 strains of P. Syringae pv. actinidifoliorum isolated in Australia, France, and New Zealand. Eleven polymorphic VNTR loci were identified in the genomes of P. Syringae pv. actinidiae biovar 3 ICMP 18744 and of P. Syringae pv. actinidifoliorum ICMP 18807. MLVA enabled the structuring of P. Syringae pv. actinidiae biovar 3 and P. Syringae pv. actinidifoliorum strains in 55 and 16 haplotypes, respectively. MLVA and discriminant analysis of principal components revealed that strains isolated in Chile, China, and New Zealand are genetically distinct from P. Syringae pv. actinidiae strains isolated in France and in Italy, which appear to be closely related at the genetic level. In contrast, no structuring was observed for P. Syringae pv. actinidifoliorum. We developed an MLVA scheme to explore the diversity within P. Syringae pv. actinidiae biovar 3 and to trace the dispersal routes of epidemic P. Syringae pv. actinidiae biovar 3 in Europe. We suggest using this MLVA scheme to trace the dispersal routes of P. Syringae pv. actinidiae at a global level.
S T Koike - One of the best experts on this subject based on the ideXlab platform.
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multilocus sequence typing of pseudomonas Syringae sensu lato confirms previously described genomospecies and permits rapid identification of p Syringae pv coriandricola and p Syringae pv apii causing bacterial leaf spot on parsley
Phytopathology, 2011Co-Authors: Carolee T Bull, Christopher R Clarke, Rongman Cai, Boris A Vinatzer, Teresa M Jardini, S T KoikeAbstract:ABSTRACT Since 2002, severe leaf spotting on parsley (Petroselinum crispum) has occurred in Monterey County, CA. Either of two different pathovars of Pseudomonas Syringae sensu lato were isolated from diseased leaves from eight distinct outbreaks and once from the same outbreak. Fragment analysis of DNA amplified between repetitive sequence polymerase chain reaction; 16S rDNA sequence analysis; and biochemical, physiological, and host range tests identified the pathogens as Pseudomonas Syringae pv. apii and P. Syringae pv. coriandricola. Koch's postulates were completed for the isolates from parsley, and host range tests with parsley isolates and pathotype strains demonstrated that P. Syringae pv. apii and P. Syringae pv. coriandricola cause leaf spot diseases on parsley, celery, and coriander or cilantro. In a multilocus sequence typing (MLST) approach, four housekeeping gene fragments were sequenced from 10 strains isolated from parsley and 56 pathotype strains of P. Syringae. Allele sequences were uplo...
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bacterial blight on arugula a new disease caused by pseudomonas Syringae pv alisalensis in california
Plant Disease, 2004Co-Authors: Carolee T Bull, Polly H Goldman, S T KoikeAbstract:Beginning in 1995, a leaf spot disease has occasionally developed on the leafy crucifer arugula (Eruca vesicaria subsp. sativa) that is grown in coastal California as a fresh market commodity used mostly in bagged salad mixes. Initially, symptoms consist of small ( = 0.758) to Pseudomonas Syringae. Amplification of repetitive bacterial sequence-based polymerase chain reaction (rep-PCR) was used to determine the relationship between the P. Syringae strains isolated from arugula and two common crucifer pathogens, P. Syringae pv. maculicola and P. Syringae pv. alisalensis (1). Using the BOXA1R primer, banding patterns for the arugula strains and the P. Syringae pv. alisalensis pathotype were similar, differing by only one band. In contrast, the banding patterns of the arugula strains differed significantly from those of P. Syringae pv. maculicola. Additionally, the arugula isolates were sensitive to a bacteriophage originally isolated for its ability to lyse P. Syringae pv. alisalensis (1). Previously, the pathogen from arugula was reported to be P. Syringae pv. maculicola (2). It is the intent of this disease note to clarify this identification. We completed Koch's postulates by confirming pathogenicity on arugula (cv. Rocket Salad). The strains were grown as nutrient broth shake cultures for 48 h at 24°C, adjusted to 108 CFU/ml, and misted onto 2- to 3-week old plants. Control plants were misted with sterile nutrient broth. After 4 to 5 days in a greenhouse (24 to 26°C), large, angular leaf lesions developed on all inoculated arugula plants. Strains were reisolated from symptomatic tissue and identified as P. Syringae pv. alisalensis. Control plants remained symptomless. Similar methods confirmed that the host range of the arugula isolates were identical to that of P. Syringae pv. alisalensis. The arugula and P. Syringae pv. alisalensis isolates caused disease on broccoli (Brassica oleracea var. botrytis cvs. Patriot and Titleist), broccoli raab (B. rapa subsp. rapa cv. Sorento), and oats (Avena sativa cv. Montezuma), while P. Syringae pv. maculicola caused disease on broccoli only. Pathogenicity tests were conducted two times with identical results. This confirms that the bacterial blight that has been occurring on commercial plantings of arugula is caused by P. Syringae pv. alisalensis. References: (1) N. A. Cintas et al.Plant Dis. 86:992, 2002. (2) S. T. Koike et al. Plant Dis. 80:464, 1996. (3) S. T. Koike. Plant Dis. 82:1063, 1998. (4) R. A. Lelliott, J. Appl. Bacteriol. 29:470, 1966.
