scholarly journals Blackleg in inadequately immunized calves and their recovery following antibiotic therapy

2020 ◽  
Vol 14 (07) ◽  
pp. 788-792
Author(s):  
Carolina C Guizelini ◽  
Otávio AC Silvestre ◽  
Carlos AN Ramos ◽  
Danilo C Gomes ◽  
Ricardo Antonio A Lemos
Keyword(s):  
Skeletal Muscle ◽  
Antibiotic Therapy ◽  
Multiplex Polymerase Chain Reaction ◽  
Booster Dose ◽  
Preventive Measure ◽  
Pcr Analysis ◽  
Chain Reaction ◽  
Vaccine Protection ◽  
Polymerase Chain ◽  
Clostridium Chauvoei

Introduction: There is consensus regarding the importance of blackleg vaccination as a preventive measure, and proper immunization protocols are available. However, few studies have evaluated the effectiveness of vaccine protection against Clostridium chauvoei and the treatment of the disease in calves exhibiting early or advanced clinical courses. This study describes twelve blackleg cases in unvaccinated calves and in calves that received a single dose of the vaccine. It also reports the recovery of some calves after antibiotic therapy. Methodology: Two necropsies of cattle dead from blackleg were performed. Fragments of skeletal muscle from these two cattle were immersed in paraffin for multiplex polymerase chain reaction (PCR) analysis. Results: Twelve calves up to nine months of age developed signs of blackleg and eight died. Ten of those 9-month-old calves had received only the first dose of a blackleg vaccine at 4 months of age, but no booster. The last two affected calves belonged to a herd that had never been vaccinated. Four out of five calves treated with penicillin for 6-7 days recovered from the disease. The diagnosis of blackleg was based on necropsy, histopathological findings and detection of C. chauvoei in skeletal muscle samples of two necropsied calves using PCR. Conclusions: The occurrence of cases only in calves that did not receive a booster dose or were not vaccinated indicated that the vaccine used was effective when performed as recommended by the manufacturer. However, neglecting the booster resulted in casualties due to blackleg.

Evaluation of Methods To Improve Detection of Escherichia coli O157:H7 in Fresh Produce by Multiplex Polymerase Chain Reaction

2003 ◽  
Vol 66 (1) ◽  
pp. 18-24 ◽  
Author(s):  
MICHAEL A. GRANT
Keyword(s):  
Escherichia Coli ◽  
Polymerase Chain Reaction ◽  
Multiplex Polymerase Chain Reaction ◽  
Fresh Produce ◽  
Nucleic Acid Amplification ◽  
Detection Sensitivity ◽  
Pcr Analysis ◽  
Chain Reaction ◽  
E Coli ◽  
Polymerase Chain

Multiplex polymerase chain reaction (PCR) analysis was used to detect two genes encoding Shiga-like toxins (stx1 and stx2) and a universal Escherichia coli gene (gadA/B) in fresh produce spiked with E. coli O157:H7. Current U.S. Food and Drug Administration procedures for the analysis of fresh produce include the use of the rinsate from an initial rinse for the analysis of several potential pathogens, including E. coli O157:H7. In this study, several procedures were evaluated for their ability to increase the sensitivity of PCR analysis of rinsates from 15 types of produce. The procedures evaluated included the preliminary clarification and concentration of templates by centrifugation and the treatment of templates with compounds reported to facilitate nucleic acid amplification, including polyvinlypolypyrrolidone (PVPP), nonfat dry milk (NFDM), and InstaGene. The preliminary concentration of rinsates resulted in moderate improvements in detection sensitivity. The use of PVPP-treated templates in PCR reaction mixtures did not further improve sensitivity, but the inclusion of NFDM-treated templates increased sensitivity by an order of magnitude for 12 rinsates. The incorporation of InstaGene also improved the detection capability of the analysis; this procedure yielded the strongest gel bands for eight rinsates. However, for four other rinsates, the use of this reagent decreased sensitivity; these four rinsates were those for the produce varieties with the largest surface areas and were the most turbid rinsates. The use of facilitating compounds to block PCR inhibition may enable an analysis for Shiga toxin–producing E. coli in fresh produce to be completed in 1 to 2 days, rather than the 5 days required for current methods.

Virus respiratoires dans les pneumonies associées aux soins

2018 ◽  
Vol 27 (3) ◽  
pp. 217-227
Author(s):  
P. Loubet ◽  
G. Voiriot ◽  
M. Neuville ◽  
B. Visseaux ◽  
J.-F. Timsit
Keyword(s):  
Polymerase Chain Reaction ◽  
Multiplex Polymerase Chain Reaction ◽  
Chain Reaction ◽  
Biologie Moléculaire ◽  
Mise En Œuvre ◽  
Polymerase Chain ◽  
Infection Bactérienne

Les pneumonies acquises à l’hôpital (PAH) sont fréquentes. À l’ère des techniques diagnostiques de biologie moléculaire (multiplex polymerase chain reaction), les rares données disponibles estiment que les virus respiratoires sont impliqués dans 22 à 32 % des épisodes. Les patients immunodéprimés constituent probablement la population la plus à risque. La présentation clinique et radiologique ne diffère pas entre pneumonies bactériennes, virales et mixtes (virus–bactérie). L’excrétion prolongée de virus respiratoires dans les voies aériennes a été rapportée chez les patients immunodéprimés. Elle pourrait promouvoir la co-infection bactérienne, associée à des durées d’hospitalisation prolongées. L’acquisition intrahospitalière a été démontrée chez tous les virus respiratoires. Elle encourage la mise en œuvre et le respect des mesures d’hygiène et de confinement, dans l’objectif de protéger soignants, visiteurs et patients. De nombreux points restent largement méconnus, relatifs aux interactions entre virus respiratoires et pathogènes non viraux, aux périodes d’incubation, ou encore aux durées d’excrétion virale. L’amélioration des techniques diagnostiques et l’accumulation de données épidémiologiques et cliniques devraient permettre de mieux appréhender le rôle des virus respiratoires dans les PAH. Cette meilleure connaissance aidera à rationaliser l’utilisation des tests de détection et facilitera l’interprétation de leurs résultats. Elle guidera aussi le clinicien dans l’utilisation future des nombreuses molécules antivirales actuellement en développement clinique chez l’homme.

Molecular Analysis of Uropathogenic E.coli Isolates from Urinary Tract Infections

2019 ◽  
Vol 19 (3) ◽  
pp. 322-326 ◽  
Author(s):  
Hassan Valadbeigi ◽  
Elham Esmaeeli ◽  
Sobhan Ghafourian ◽  
Abbas Maleki ◽  
Nourkhoda Sadeghifard
Keyword(s):  
Escherichia Coli ◽  
Polymerase Chain Reaction ◽  
Urinary Tract ◽  
Urinary Tract Infections ◽  
Multiplex Polymerase Chain Reaction ◽  
Virulence Genes ◽  
Uropathogenic Escherichia Coli ◽  
Chain Reaction ◽  
Polymerase Chain ◽  
Tract Infections

Introduction: The aim of the current study was to investigate the prevalence of virulence genes in uropathogenic Escherichia coli (UPEC) isolates in Ilam. Materials and Methods: For this purpose, a total of 80 UPEC isolates were collected for patients with UTIs during a 6 months period. The multiplex polymerase chain reaction (multiplex PCR) was used to detect the papEF, fimH, iucD, hlyA, fyuA, and ompT genes. Results: The prevalence of fimH, papEF, iucD, fyuA, hlyA, hlyA, and ompT genes were 87.5%, 47.5%, 60%, 67.5%, 27.5%, 47.5% and 71.2%, respectively. Among all of the isolates, 27 profiles were obtained. Conclusion: Our findings demonstrated that the most prevalence was found for fimH, and different distribution of virulence genes suggested different ability of pathogenicity.

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