scholarly journals On-farm colorimetric detection of Pasteurella multocida, Mannheimia haemolytica, and Histophilus somni in crude bovine nasal samples

2021 ◽  
Vol 52 (1) ◽  
Author(s):  
Ana Pascual-Garrigos ◽  
Murali Kannan Maruthamuthu ◽  
Aaron Ault ◽  
Josiah Levi Davidson ◽  
Grigorii Rudakov ◽  
...  
Keyword(s):  
Pathogen Detection ◽  
Pasteurella Multocida ◽  
Colorimetric Detection ◽  
Lamp Assay ◽  
Mannheimia Haemolytica ◽  
Analytical Sensitivity ◽  
Histophilus Somni ◽  
Polymerase Chain ◽  
On Farm ◽  
Significant Health

AbstractThis work modifies a loop-mediated isothermal amplification (LAMP) assay to detect the bovine respiratory disease (BRD) bacterial pathogens Pasteurella multocida, Mannheimia haemolytica, and Histophilus somni in a colorimetric format on a farm. BRD causes a significant health and economic burden worldwide that partially stems from the challenges involved in determining the pathogens causing the disease. Methods such as polymerase chain reaction (PCR) have the potential to identify the causative pathogens but require lab equipment and extensive sample processing making the process lengthy and expensive. To combat this limitation, LAMP allows accurate pathogen detection in unprocessed samples by the naked eye allowing for potentially faster and more precise diagnostics on the farm. The assay developed here offers 66.7–100% analytical sensitivity, and 100% analytical specificity (using contrived samples) while providing 60–100% concordance with PCR results when tested on five steers in a feedlot. The use of a consumer-grade water bath enabled on-farm execution by collecting a nasal swab from cattle and provided a colorimetric result within 60 min. Such an assay holds the potential to provide rapid pen-side diagnostics to cattle producers and veterinarians.

scholarly journals Differences between Predicted Outer Membrane Proteins of Pasteurella multocida, Histophilus somni, and Genotype 1 and 2 Mannheimia haemolytica Strains Isolated from Cattle

Genome ◽  
2021 ◽  
Author(s):  
Emily L Wynn ◽  
Michael Clawson
Keyword(s):  
Membrane Proteins ◽  
Outer Membrane ◽  
Pasteurella Multocida ◽  
Outer Membrane Proteins ◽  
Host Immunity ◽  
Mannheimia Haemolytica ◽  
Genotype 1 ◽  
The Core ◽  
Histophilus Somni ◽  
Genotype 2

Common bacterial causes of bovine respiratory disease (BRD) include Histophilus somni, Mannheimia haemolytica, and Pasteurella multocida. Within M. haemolytica, two major genotypes are commonly found in cattle (1 and 2), however, genotype 2 strains are isolated from diseased lungs much more frequently than genotype 1 strains. Outer membrane proteins (OMPs) of H. somni, P. multocida, and genotype 2 M. haemolytica may be important factors for acquired host immunity. Predicted OMP differences between genotype 1 and 2 M. haemolytica have been previously identified. In this study, we expanded that focus to include bovine-isolated strain genomes representing all three species and the two M. haemolytica genotypes. Reported here are the core genomes unique to each of them, core genomes shared between some or all combinations of the three species and two M. haemolytica genotypes, and predicted OMPs within these core genomes. The OMPs identified in this study are potential candidates for further study and the development of interventions against BRD.

scholarly journals Development of loop-mediated isothermal amplification (LAMP) assay for detection of Pseudocercospora angolensis in sweet orange

2021 ◽  
Author(s):  
Patricia Driciru ◽  
M Claire Mugasa ◽  
Robert Acidri ◽  
John Adriko
Keyword(s):  
Yield Loss ◽  
Sweet Orange ◽  
Lamp Assay ◽  
Effective Control ◽  
Analytical Sensitivity ◽  
Chain Reaction ◽  
Predictive Values ◽  
Fruit Spot ◽  
Orange Leaf ◽  
Polymerase Chain

AbstractPseudocercospora angolensis is the causative agent of Pseudocercospora leaf and fruit spot disease in citrus which can result in up to 100% yield loss. Early diagnosis of this disease is vital for effective control. This study aimed at developing a loop-mediated amplification (LAMP) system for detecting P. angolensis in sweet oranges in comparison with Polymerase Chain Reaction (PCR) and using microscopy as a gold standard. Twelve non-target species were used to assess the analytical specificity of LAMP and PCR whereas the analytical sensitivity was determined using serial dilutions of P. angolensis DNA. The diagnostic accuracies of the two assays were evaluated using DNA from 150 diseased and 50 non-diseased sweet orange leaf samples. The analytical sensitivity and detection time of LAMP were of 10−4 ng/ μl and 40 minutes, respectively. The analytical sensitivity of PCR was 10ng/μl and it was specific to P. angolensis whereas three relatives of P. angolensis were detectable by LAMP. The diagnostic sensitivities of LAMP (93%) and microscopy (100%) were significantly different (X2 = 8.38, P = 0.0038) unlike the diagnostic specificities (90%) and (100%), respectively (X2 = 3.37, P = 0.066). Microscopy was significantly more sensitive than PCR (32.6%) (X2 = 149.26, P < 2.2e-16) and equally specific as PCR (P=NA). The positive predictive values of PCR and LAMP were 100% and 96.5% respectively whereas the negative predictive values were 33.1% and 81.8% respectively. The LAMP assay developed in this study offers a great tool for routine screening sweet orange samples for P. angolensis.

scholarly journals A ten-year (2000–2009) study of antimicrobial susceptibility of bacteria that cause bovine respiratory disease complex—Mannheimia haemolytica, Pasteurella multocida, and Histophilus somni—in the United States and Canada

2012 ◽  
Vol 24 (5) ◽  
pp. 932-944 ◽  
Author(s):  
Ellen Portis ◽  
Cynthia Lindeman ◽  
Lacie Johansen ◽  
Gillian Stoltman
Keyword(s):  
Pasteurella Multocida ◽  
Inhibitory Concentration ◽  
The United States ◽  
Mannheimia Haemolytica ◽  
In Vitro Susceptibility ◽  
Histophilus Somni ◽  
Bovine Respiratory Disease Complex ◽  
Year 2000 ◽  
Over Time

Bovine isolates of Mannheimia haemolytica, Pasteurella multocida, and Histophilus somni, collected from 2000 to 2009, were tested for in vitro susceptibility to ceftiofur, penicillin, danofloxacin, enrofloxacin, florfenicol, tetracycline, tilmicosin, and tulathromycin. Ceftiofur remained very active against all isolates. Penicillin retained good activity against P. multocida and H. somni isolates with no appreciable changes in susceptibility or minimal inhibitory concentration (MIC) distributions with time. While there was no obvious trend, the percent of M. haemolytica that were susceptible to penicillin ranged from 40.9% to 66.7%. Danofloxacin MIC50 and MIC90 values for M. haemolytica and P. multocida did not change beyond a single dilution over the 6 years it was included in the testing panel. The MIC90 for H. somni increased beyond 1 dilution. Enrofloxacin MIC50 values for the 3 pathogens also did not change over time, unlike the MIC90 values, which increased by at least 4-doubling dilutions. Ninety percent or more of M. haemolytica and H. somni isolates were susceptible to florfenicol, while susceptibility among P. multocida was 79% or greater. Less than 50% of the isolates tested as susceptible to tetracycline in many of the years. All 3 organisms showed declines in tilmicosin and tulathromycin MIC50 and MIC90 values over the years in which they were tested.

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