Essential oils inhibit the bovine respiratory pathogens Mannheimia haemolytica , Pasteurella multocida and Histophilus somni and have limited effects on commensal bacteria and turbinate cells in vitro

2019 ◽  
Vol 126 (6) ◽  
pp. 1668-1682 ◽  
Author(s):  
S. Amat ◽  
D. Baines ◽  
E. Timsit ◽  
J. Hallewell ◽  
T.W. Alexander
2012 ◽  
Vol 24 (5) ◽  
pp. 932-944 ◽  
Author(s):  
Ellen Portis ◽  
Cynthia Lindeman ◽  
Lacie Johansen ◽  
Gillian Stoltman

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.


2019 ◽  
Vol 15 (02) ◽  
pp. 22-25
Author(s):  
Sunaina Thakur ◽  
Subhash Verma ◽  
Prasenjit Dhar ◽  
Mandeep Sharma

Respiratory infections of sheep and goats cause heavy morbidity and mortality, leading to huge economic losses. Conventional methods of diagnosis that include isolation and identification of incriminating microbes are time-consuming and fraught with logistic challenges. Direct detection of incriminating microbes using molecular tools is gaining popularity in clinical, microbiological settings. In this study, a total of 50 samples (44 nasal swabs and 6 lung tissues) from sheep and goats were screened for the detection of different bacterial species by in vitro amplification of genus or species-specific genes. Histophilus somni was detected in 2% goat samples, Trueperella pyogenes in 20% goat nasal swabs, whereas 22% goat nasal swab samples were found positive for Mycoplasma spp. None of the samples from sheep was detected positive for H. somni, T. pyogenes, Mycoplasma spp. Similarly, all samples, irrespective, whether from sheep or goats, showed negative results for Pasteurella multocida, Mannheimia haemolytica, and Corynebacterium pseudotuberculosis.


2021 ◽  
Vol 8 ◽  
Author(s):  
Alicia F. Klompmaker ◽  
Maria Brydensholt ◽  
Anne Marie Michelsen ◽  
Matthew J. Denwood ◽  
Carsten T. Kirkeby ◽  
...  

Bovine respiratory disease (BRD) results from interactions between pathogens, environmental stressors, and host factors. Obtaining a diagnosis of the causal pathogens is challenging but the use of high-throughput real-time PCR (rtPCR) may help target preventive and therapeutic interventions. The aim of this study was to improve the interpretation of rtPCR results by analysing their associations with clinical observations. The objective was to develop and illustrate a field-data driven statistical method to guide the selection of relevant quantification cycle cut-off values for pathogens associated with BRD for the high-throughput rtPCR system “Fluidigm BioMark HD” based on nasal swabs from calves. We used data from 36 herds enrolled in a Danish field study where 340 calves within pre-determined age-groups were subject to clinical examination and nasal swabs up to four times. The samples were analysed with the rtPCR system. Each of the 1,025 observation units were classified as sick with BRD or healthy, based on clinical scores. The optimal rtPCR results to predict BRD were investigated for Pasteurella multocida, Mycoplasma bovis, Histophilus somni, Mannheimia haemolytica, and Trueperella pyogenes by interpreting scatterplots and results of mixed effects logistic regression models. The clinically relevant rtPCR cut-off suggested for P. multocida and M. bovis was ≤ 21.3. For H. somni it was ≤ 17.4, while no cut-off could be determined for M. haemolytica and T. pyogenes. The demonstrated approach can provide objective support in the choice of clinically relevant cut-offs. However, for robust performance of the regression model sufficient amounts of suitable data are required.


2019 ◽  
Vol 64 (No. 02) ◽  
pp. 67-77 ◽  
Author(s):  
K Nedbalcova ◽  
M Zouharova ◽  
D Sperling

The post-antibiotic effect is defined as the period of bacterial growth suppression that persists after a limited exposure of organisms to antimicrobials and knowledge of its duration is important in establishing and optimising current dosing schedules for the treatment of bacterial infections. The post-antibiotic effect of marbofloxacin, enrofloxacin and amoxicillin were evaluated in vitro for Actinobacillus pleuropneumoniae, Haemophilus parasuis and Pasteurella multocida strains which originated from clinical samples of diseased pigs and were confirmed as susceptible to all tested antimicrobials based on determination of minimal inhibitory concentrations. The post-antibiotic effect for individual antimicrobials was monitored at five and ten times minimum inhibitory concentrations for one and two hours. The duration of the post-antibiotic effect for tested antimicrobials was found to exhibit the following order for all tested pathogens: marbofloxacin > enrofloxacin > amoxicillin. The longest duration of post-antibiotic effect of all tested antimicrobials was found in A. pleuropneumoniae and the shortest post-antibiotic effect duration was detected in P. multocida. No statistical differences in post-antibiotic effect duration were found within marbofloxacin and enrofloxacin in A. pleuropneumoniae and H. parasuis strains. In P. multocida strains there was a statistically significant difference (P = 0.0189). On the other hand, the differences between amoxicillin and marbofloxacin or enrofloxacin were statistically significant in all cases (P-values ranged between 0.0058 and 0.008). The prolonged post-antibiotic effect of fluoroquinolones and amoxicillin on important Gram-negative swine pathogens was confirmed. The results can be used to clarify the effect and mechanism of action of antimicrobial drugs in veterinary medicine.


2019 ◽  
Vol 97 (Supplement_3) ◽  
pp. 212-212
Author(s):  
Lourdes Migura-Garcia ◽  
Sonia Marti ◽  
Anna Aris ◽  
Ana Perez de Rozas ◽  
Carolina Tejero ◽  
...  

Abstract The current production system involves movement of calves combined with mixing animals, favouring the transmission of respiratory pathogens and increasing the risk of using antimicrobials. The aim of the study was to determine the presence and resistant profiles of Pasteurella multocida, Mannheimia haemolytica and Moraxella in the lungs of calves at arrival to the farm and after treatment with tulathromycin and florfenicol. Thoracic ultrasonography was performed in two batches of calves (n = 65 and 120, age=26±11.0, weight=45-55kg) at arrival, to select 27 calves/batch with lesions from low to severe. Bronchoalveolar lavage fluid (BALF) was collected on arrival (D0), D20 and D34, and also on D7 for the second batch. Pasteurella, Mannheimia and Moraxella were identified by VITEK. Detection of Mycoplasma bovis was performed by PCR. Minimal inhibitory concentration (MIC) was determined for 18 antimicrobials. Clinical breakpoints were defined by Clinical Laboratory Standards Institute. ERIC-PCR was performed in all isolates to assess similarities. Time effect was analysed by MIXED Procedure (SAS). At D0, 16 out of 54 BALFs contained P. multocida (n = 11), M. haemolytica (n = 5) and Moraxella (n = 4). The number of calves positive for primary pathogens decreased (P < 0.001) at D7 and D20, whereas by D34 positive animals leapt up to 21. MIC results demonstrated that P. multocida and M. haemolytica obtained at D0 were pansusceptible. Isolates of P. multocida collected after treatment, exhibited resistance to oxytetracycline, tilmicosin, tulathromycin, danofloxacin and enrofloxacin. ERIC-PCR demonstrated similar profiles of P. multocida and Moraxellain the two batches of calves after D7. Primary pathogens were susceptible to the initial treatment, however M. bovis was detected in all animals after D7. Resistant species appeared to recolonize the lungs after D34. ERIC-profile demonstrated that isolates recovered after treatment were different from those colonizing the lungs at arrival, suggesting recirculation of resistant bacteria between batches.


2021 ◽  
Vol 8 ◽  
Author(s):  
Angela Fanelli ◽  
Margie Cirilli ◽  
Maria Stella Lucente ◽  
Aya Attia Koraney Zarea ◽  
Domenico Buonavoglia ◽  
...  

Mycoplasma bovis is increasingly recognized worldwide as an important cause of disease with major welfare and production impairments on cattle rearing. Although it was detected in veal calves and beef cattle, little is known on the infection impact and on its temporal morbidity pattern in Italian dairy herds. Thus, this study aimed to investigate the involvement of M. bovis on fatal calf pneumonia outbreaks that occurred during 2009–2019 in 64 Italian dairy farms. Furthermore, a deeper diagnostic workup of concurrent infection with other viral and bacterial respiratory pathogens was assessed. Out of the investigated fatal pneumonia cases, M. bovis was frequently detected (animal prevalence, 16.16%; 95%CI, 11.82–21.33; herd prevalence, 26.56; 95%CI, 16.29–39.08) either as the single agent of the disease in more than half of the positive samples (20/37) or in concurrent infections with Histophilus somni (9/37, 24.3%), Mannheimia haemolytica (6/37, 16.621%), Trueperella pyogenes (1/37, 2.70%), Pasteurella multocida (1/37, 2.70%), bovine respiratory syncytial virus (5/37, 13.51%), and bovine viral diarrhea virus (2/37, 5.55%). Based on time-series analysis, M. bovis was recorded in the area since 2009 with outbreaks displaying a clear morbidity seasonal pattern with peaks in April (43.21%) and in September (13.51%). This might be due to the stressing conditions during spring and late summer periods. Results of this study highlight that M. bovis infection warrants consideration, and control measures are needed given its involvement in lethal pneumonia outbreaks in dairy herds from an extended area.


Author(s):  
Darshana B. Bhaisare ◽  
D. Thyagarajan ◽  
R. Richard Churchil ◽  
N. Punniamurthy

Two in-vitro experiments were conducted to evaluate the antibacterial, antifungal and antiviral properties of essential oil of herbal seeds. In-vitro antimicrobial properties of essential oils of phytobiotics was determined by disc diffusion method against Escherichia coli, Staphylococcus aureus, Pasteurella multocida and Salmonella typhi and two fungi namely Aspergillus fumigatus and Candida albicans. Thyme oil had statistically similar or significantly (P<0.05) higher inhibition zone against all the bacterial and fungal species compared to standard antibiotic, chloramphenicol or antifungal drug, nystatin. Fenugreek oil was not found to be active against microbes compared to control. Fennel and cumin oils had statistically similar or significantly (P<0.05) higher inhibition zone against all microbes except Staphylococcus aureus and Salmonella typhi compared to control. Antiviral activity of essential oils was determined by anti-NDV assay against New Castle disease virus (LaSota). The results indicated that essential oils of herbal seeds do not possess antiviral activity against NDV LaSota virus at 1mg/ml concentration.


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