scholarly journals Proximity-Dependent Inhibition of Growth of Mannheimia haemolytica by Pasteurella multocida

2012 ◽  
Vol 78 (18) ◽  
pp. 6683-6688 ◽  
Author(s):  
Jegarubee Bavananthasivam ◽  
Rohana P. Dassanayake ◽  
Abirami Kugadas ◽  
Sudarvili Shanthalingam ◽  
Douglas R. Call ◽  
...  

ABSTRACTMannheimia haemolytica,Pasteurella multocida, andBibersteinia trehalosihave been identified in the lungs of pneumonic bighorn sheep (BHS;Ovis canadensis). Of these pathogens,M. haemolyticahas been shown to consistently cause fatal pneumonia in BHS under experimental conditions. However,M. haemolyticahas been isolated by culture less frequently than the other bacteria. We hypothesized that the growth ofM. haemolyticais inhibited by other bacteria in the lungs of BHS. The objective of this study was to determine whetherP. multocidainhibits the growth ofM. haemolytica. Although in monoculture both bacteria exhibited similar growth characteristics, in coculture withP. multocidathere was a clear inhibition of growth ofM. haemolytica. The inhibition was detected at mid-log phase and continued through the stationary phase. When cultured in the same medium, the growth ofM. haemolyticawas inhibited when both bacteria were separated by a membrane that allowed contact (pore size, 8.0 μm) but not when they were separated by a membrane that limited contact (pore size, 0.4 μm). Lytic bacteriophages or bactericidal compounds could not be detected in the culture supernatant fluid from monocultures ofP. multocidaor fromP. multocida-M. haemolyticacocultures. These results indicate thatP. multocidainhibits the growth ofM. haemolyticaby a contact- or proximity-dependent mechanism. If the inhibition of growth ofM. haemolyticabyP. multocidaoccursin vivoas well, it could explain the inconsistent isolation ofM. haemolyticafrom the lungs of pneumonic BHS.

2009 ◽  
Vol 76 (4) ◽  
pp. 1008-1013 ◽  
Author(s):  
Rohana P. Dassanayake ◽  
Douglas R. Call ◽  
Ashish A. Sawant ◽  
N. Carol Casavant ◽  
Glen C. Weiser ◽  
...  

ABSTRACT Mannheimia (Pasteurella) haemolytica is the only pathogen that consistently causes severe bronchopneumonia and rapid death of bighorn sheep (BHS; Ovis canadensis) under experimental conditions. Paradoxically, Bibersteinia (Pasteurella) trehalosi and Pasteurella multocida have been isolated from BHS pneumonic lungs much more frequently than M. haemolytica. These observations suggest that there may be an interaction between these bacteria, and we hypothesized that B. trehalosi overgrows or otherwise inhibits the growth of M. haemolytica. Growth curves (monoculture) demonstrated that B. trehalosi has a shorter doubling time (∼10 min versus ∼27 min) and consistently achieves 3-log higher cell density (CFU/ml) compared to M. haemolytica. During coculture M. haemolytica growth was inhibited when B. trehalosi entered stationary phase (6 h) resulting in a final cell density for M. haemolytica that was 6 to 9 logs lower than expected with growth in the absence of B. trehalosi. Coculture supernatant failed to inhibit M. haemolytica growth on agar or in broth, indicating no obvious involvement of lytic phages, bacteriocins, or quorum-sensing systems. This observation was confirmed by limited growth inhibition of M. haemolytica when both pathogens were cultured in the same media but separated by a filter (0.4-μm pore size) that limited contact between the two bacterial populations. There was significant growth inhibition of M. haemolytica when the populations were separated by membranes with a pore size of 8 μm that allowed free contact. These observations demonstrate that B. trehalosi can both outgrow and inhibit M. haemolytica growth with the latter related to a proximity- or contact-dependent mechanism.


2011 ◽  
Vol 18 (7) ◽  
pp. 1133-1138 ◽  
Author(s):  
Caroline N. Herndon ◽  
Sudarvili Shanthalingam ◽  
Donald P. Knowles ◽  
Douglas R. Call ◽  
Subramaniam Srikumaran

ABSTRACTMannheimia haemolyticaconsistently causes fatal bronchopneumonia in bighorn sheep (BHS;Ovis canadensis) under natural and experimental conditions. Leukotoxin is the primary virulence factor of this organism. BHS are more susceptible to developing fatal pneumonia than the related speciesOvis aries(domestic sheep [DS]). In BHS herds affected by pneumonia, lamb recruitment is severely impaired for years subsequent to an outbreak. We hypothesized that a lack of maternally derived antibodies (Abs) againstM. haemolyticaprovides an immunologic basis for enhanced susceptibility of BH lambs to population-limiting pneumonia. Therefore, the objective of this study was to determine the titers of Abs directed againstM. haemolyticain the sera of BH and domestic lambs at birth through 12 weeks of age. Results revealed that BH lambs had approximately 18-fold lower titers of Ab against surface antigens ofM. haemolyticaand approximately 20-fold lower titers of leukotoxin-neutralizing Abs than domestic lambs. The titers of leukotoxin-neutralizing Abs in the serum and colostrum samples of BH ewes were approximately 157- and 50-fold lower than those for domestic ewes, respectively. Comparatively, the higher titers of parainfluenza 3 virus-neutralizing Abs in the BH lambs ruled out the possibility that these BHS had an impaired ability to passively transfer Abs to their lambs. These results suggest that lower levels of leukotoxin-neutralizing Abs in the sera of BH ewes, and resultant low Ab titers in their lambs, may be a critical factor in the poor lamb recruitment in herds affected by pneumonia.


2016 ◽  
Vol 4 (4) ◽  
Author(s):  
Abirami Kugadas ◽  
Jodi L. Humann ◽  
Sebastián Aguilar Pierlé ◽  
Subramaniam Srikumaran ◽  
Kelly A. Brayton

Here, we report the genome sequence for Bibersteinia trehalosi strain Y31, isolated from the lungs of a bighorn sheep ( Ovis canadensis ) that had succumbed to pneumonia, which exhibits proximity-dependent inhibition (PDI) of Mannheimia haemolytica . The sequence will be used to understand the mechanism of PDI for these organisms.


FEBS Letters ◽  
1996 ◽  
Vol 395 (2-3) ◽  
pp. 170-173 ◽  
Author(s):  
J.Raimund Wieser ◽  
Anja Heisner ◽  
Peer Stehling ◽  
Franz Oesch ◽  
Werner Reutter

2016 ◽  
Vol 60 (6) ◽  
pp. 3415-3418 ◽  
Author(s):  
Esther Zander ◽  
Harald Seifert ◽  
Paul G. Higgins

Different physiological conditions, such as NaCl, low pH, and sodium salicylate, have been shown to affect antibiotic resistance determinants inAcinetobacter baumanniiisolates. Therefore, the aim of this study was to investigate the effects of NaCl, sodium salicylate, and low pH on the susceptibility ofA. baumanniito carbapenem. We cloned genes encoding oxacillinases (OXA) of different subclasses, with their associated promoters, from carbapenem-resistantA. baumanniiisolates into the same vector and transferred them to theA. baumanniireference strains ATCC 19606 and ATCC 17978. Carbapenem MICs were determined at least in triplicate by agar dilution under standard conditions, as well as in the presence of 200 mM NaCl or 16 mM sodium salicylate, or at pH 5.8. OXA-58-like gene expression was determined by reverse transcription-quantitative PCR (qRT-PCR). Under some experimental conditions, significant MIC reductions were shown for some transformants but not for others. Only in one instance were all transformants harboring the same OXA affected by the same condition: at pH 5.8, the imipenem and meropenem MICs for strains expressing OXA-58-like enzymes decreased from a resistant level (32 to 64 mg/liter) to an intermediate-susceptible level (8 mg/liter). However,blaOXA-58-likegene expression remained the same. MICs for both wild-type reference strains were not affected by the conditions tested. Our results indicate that the effects of the experimental conditions tested on OXAin vivoare mostly strain dependent. MICs were not reduced to wild-type levels, suggesting that the conditions tested do not lead to complete OXA inhibition in the bacterial cell.


2020 ◽  
Vol 21 (8) ◽  
pp. 2739
Author(s):  
Arshiya Banu ◽  
Alistair J. Lax ◽  
Agamemnon E. Grigoriadis

Many Pasteurella multocida strains are carried as commensals, while some cause disease in animals and humans. Some type D strains cause atrophic rhinitis in pigs, where the causative agent is known to be the Pasteurella multocida toxin (PMT). PMT activates three families of G-proteins—Gq/11, G12/13, and Gi/o—leading to cellular mitogenesis and other sequelae. The effects of PMT on whole animals in vivo have been investigated previously, but only at the level of organ-specific pathogenesis. We report here the first study to screen all the organs targeted by the toxin by using the QE antibody that recognizes only PMT-modified G-proteins. Under our experimental conditions, short-term treatment of PMT is shown to have multiple in vivo targets, demonstrating G-alpha protein modification, stimulation of proliferation markers and expression of active β-catenin in a tissue- and cell-specific manner. This highlights the usefulness of PMT as an important tool for dissecting the specific roles of different G-alpha proteins in vivo.


Author(s):  
P.N. Shastin ◽  
A.V. Kapustin ◽  
E.A. Yakimova ◽  
E.V. Ivanov ◽  
A.I. Laishevtsev

The paper presents the results of bacterial screening of goat and sheep breeding enterprises in certain regions of Russia (Tver, Moscow, Smolensk regions, as well as the Republic of Mari-El and Tatarstan), conducted in the period from 2018 to 2021. In the course of this work, 556 samples of sectional material (heart, lungs, gastrointestinal tract, spleen, kidneys, liver, lymph nodes, breast, flushes from the genitourinary system, as well as exudate from purulent lesions) were subjected to a comprehensive bacteriological study. As a result of the conducted studies, 1223 isolates belonging to 25 families (111 bacterial species) were isolated and identified (by the method of time-of-flight mass spectrometry MALDI-ToF). According to the data obtained, the incidence of Escherichia coli isolation was 10.95%, Trueperella pyogenes – 5.47%, Staphylococcus aureus – 5.31%, Proteus mirabilis – 4.08%, Mannheimia haemolytica – 4.00%, Enterococcus faecalis – 3.76%, Enterobacter cloacea and Staphylococcus haemolyticus – 3.59%, Streptococcus dysgalactiae – 3.51%, Pasteurella multocida – 3.27%, Acinetobacter lwoffii – 2.78%, Staphylococcus cohnii – 2.61%, Bibersteinia trehalosi – 2.29%, Pseudomonas aeruginosa – 2.12%, Bacillus cereus and Micrococcus luteus – 1.96%, Corynebacterium pseudotuberculosis and Staphylococcus equorum – 1.88%, Aerococcus viridans – 1.80%, Corynebacterium xerosis – 1.72%, Clostridium perfringens, Streptococcus mitis and Streptococcus pyogenes – 1.39%, Staphylococcus chromogenes and Streptococcus entericus – 1.14%, respectively. The incidence of isolation of other types of microorganisms was below 1%. The data obtained indicate the circulation of a wide range of bacteria in goat and sheep breeding enterprises of the Russian Federation, some of which should be positioned as pathogenic flora (for example, Pasteurella multocida, Listeria monocytogenes, Salmonella enteritidis, Salmonella typhimurium, Clostridium perfringens, etc.), some as conditionally pathogenic (Trueperella pyogenes, Staphylococcus aureus, Bibersteinia trehalosi, Mannheimia haemolytica, Pseudomonas aeruginosa, Moraxella bovis, Moraxella bovoculi, etc.), as well as the normal flora of the animal body. It is worth focusing on these data when conducting a survey of livestock enterprises in order to establish an objective epizootic situation, including taking into account the possibility of circulating pathogens of factor diseases.


2019 ◽  
Vol 85 (21) ◽  
Author(s):  
Samat Amat ◽  
Edouard Timsit ◽  
Danica Baines ◽  
Jay Yanke ◽  
Trevor W. Alexander

ABSTRACT Bovine respiratory disease (BRD) is a major cause of morbidity and mortality in beef cattle. Recent evidence suggests that commensal bacteria of the bovine nasopharynx have an important role in maintaining respiratory health by providing colonization resistance against pathogens. The objective of this study was to screen and select bacterial therapeutic candidates from the nasopharynxes of feedlot cattle to mitigate the BRD pathogen Mannheimia haemolytica. In a stepwise approach, bacteria (n = 300) isolated from the nasopharynxes of 100 healthy feedlot cattle were identified and initially screened (n = 178 isolates from 12 different genera) for growth inhibition of M. haemolytica. Subsequently, selected isolates were evaluated for the ability to adhere to bovine turbinate (BT) cells (n = 47), compete against M. haemolytica for BT cell adherence (n = 15), and modulate gene expression in BT cells (n = 10). Lactobacillus strains had the strongest inhibition of M. haemolytica, with 88% of the isolates (n =33) having inhibition zones ranging from 17 to 23 mm. Adherence to BT cells ranged from 3.4 to 8.0 log10 CFU per 105 BT cells. All the isolates tested in competition assays reduced M. haemolytica adherence to BT cells (32% to 78%). Among 84 bovine genes evaluated, selected isolates upregulated expression of interleukin 8 (IL-8) and IL-6 (P < 0.05). After ranking isolates for greatest inhibition, adhesion, competition, and immunomodulation properties, 6 Lactobacillus strains from 4 different species were selected as the best candidates for further development as intranasal bacterial therapeutics to mitigate M. haemolytica infection in feedlot cattle. IMPORTANCE Bovine respiratory disease (BRD) is a significant animal health issue impacting the beef industry. Current BRD prevention strategies rely mainly on metaphylactic use of antimicrobials when cattle enter feedlots. However, a recent increase in BRD-associated bacterial pathogens that are resistant to metaphylactic antimicrobials highlights a pressing need for the development of novel mitigation strategies. Based upon previous research showing the importance of respiratory commensal bacteria in protecting against bronchopneumonia, this study aimed to develop bacterial therapeutics that could be used to mitigate the BRD pathogen Mannheimia haemolytica. Bacteria isolated from the respiratory tracts of healthy cattle were characterized for their inhibitory, adhesive, and immunomodulatory properties. In total, 6 strains were identified as having the best properties for use as intranasal therapeutics to inhibit M. haemolytica. If successful in vivo, these strains offer an alternative to metaphylactic antimicrobial use in feedlot cattle for mitigating BRD.


2013 ◽  
Vol 58 (3) ◽  
pp. 1284-1293 ◽  
Author(s):  
Alessandra Oliva ◽  
Ulrika Furustrand Tafin ◽  
Elena Maryka Maiolo ◽  
Safaa Jeddari ◽  
Bertrand Bétrisey ◽  
...  

ABSTRACTEnterococcal implant-associated infections are difficult to treat because antibiotics generally lack activity against enterococcal biofilms. We investigated fosfomycin, rifampin, and their combinations against planktonic and adherentEnterococcus faecalis(ATCC 19433)in vitroand in a foreign-body infection model. The MIC/MBClogvalues were 32/>512 μg/ml for fosfomycin, 4/>64 μg/ml for rifampin, 1/2 μg/ml for ampicillin, 2/>256 μg/ml for linezolid, 16/32 μg/ml for gentamicin, 1/>64 μg/ml for vancomycin, and 1/5 μg/ml for daptomycin. In time-kill studies, fosfomycin was bactericidal at 8× and 16× MIC, but regrowth of resistant strains occurred after 24 h. With the exception of gentamicin, no complete inhibition of growth-related heat production was observed with other antimicrobials on early (3 h) or mature (24 h) biofilms. In the animal model, fosfomycin alone or in combination with daptomycin reduced planktonic counts by ≈4 log10CFU/ml below the levels before treatment. Fosfomycin cleared planktonic bacteria from 74% of cage fluids (i.e., no growth in aspirated fluid) and eradicated biofilm bacteria from 43% of cages (i.e., no growth from removed cages). In combination with gentamicin, fosfomycin cleared 77% and cured 58% of cages; in combination with vancomycin, fosfomycin cleared 33% and cured 18% of cages; in combination with daptomycin, fosfomycin cleared 75% and cured 17% of cages. Rifampin showed no activity on planktonic or adherentE. faecalis, whereas in combination with daptomycin it cured 17% and with fosfomycin it cured 25% of cages. Emergence of fosfomycin resistance was not observedin vivo. In conclusion, fosfomycin showed activity against planktonic and adherentE. faecalis. Its role against enterococcal biofilms should be further investigated, especially in combination with rifampin and/or daptomycin treatment.


2011 ◽  
Vol 18 (10) ◽  
pp. 1689-1694 ◽  
Author(s):  
Renuka Subramaniam ◽  
Sudarvili Shanthalingam ◽  
Jegarubee Bavananthasivam ◽  
Abirami Kugadas ◽  
Kathleen A. Potter ◽  
...  

ABSTRACTBighorn sheep (BHS) are more susceptible than domestic sheep (DS) toMannheimia haemolyticapneumonia. Although both species carryM. haemolyticaas a commensal bacterium in the nasopharynx, DS carry mostly leukotoxin (Lkt)-positive strains while BHS carry Lkt-negative strains. Consequently, antibodies to surface antigens and Lkt are present at much higher titers in DS than in BHS. The objective of this study was to determine whether repeated immunization of BHS with multivalentMannheimia-Bibersteiniavaccine will protect them uponM. haemolyticachallenge. Four BHS were vaccinated with a culture supernatant vaccine prepared fromM. haemolyticaserotypes A1 and A2 andBibersteinia trehalosiserotype T10 on days 0, 21, 35, 49, and 77. Four other BHS were used as nonvaccinated controls. On the day of challenge, 12 days after the last immunization, the mean serum titers of Lkt-neutralizing antibodies and antibodies to surface antigens againstM. haemolyticawere 1:160 and 1:4,000, respectively. Following intranasal challenge withM. haemolyticaA2 (1 × 105CFU), all four control BHS died within 48 h. Necropsy revealed acute fibrinonecrotic pneumonia characteristic ofM. haemolyticainfection. None of the vaccinated BHS died during the 8 weeks postchallenge observation period. Radiography at 3 weeks postchallenge revealed no lung lesions in two vaccinated BHS and mild lesions in the other two, which resolved by 8 weeks postchallenge. These results indicate that if BHS can be induced to develop high titers of Lkt-neutralizing antibodies and antibodies to surface antigens, they are likely to surviveM. haemolyticachallenge which is likely to reduce the BHS population decline due to pneumonia.


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