In vitro antimicrobial susceptibility of Mycoplasma bovis clinical isolates recovered from bison (Bison bison)

Mycoplasma bovis is a pathogen globally affecting cattle and bison herds, causing pneumonia, arthritis, mastitis, abortions, and other symptoms, leading to huge economic losses. Many studies have been done regarding the antimicrobial susceptibility of M. bovis isolated from cattle, but no such study is available for isolates recovered from bison. For the first time, in vitro susceptibilities of 40 M. bovis clinical isolates collected from bison herds in Canada are reported here. Minimal inhibitory concentration (MIC) values were determined using Sensititre® plates. The most effective MIC50 and MIC90 were for spectinomycin (1 and >64 μg/mL), tiamulin (1 and >32 μg/mL), and tulathromycin (16 and 64 μg/mL), whereas tetracyclines, fluoroquinolones, and florfenicol failed to inhibit growth of M. bovis bison isolates. Isolates were nonsusceptible to tetracyclines (100%), fluoroquinolones (97.5%), and tilmicosin (100%), whereas the highest susceptibility of bison clinical isolates was seen with spectinomycin (95%) and tulathromycin (67.5%). Two lung isolates (Mb283 and 348) were found resistant to both spectinomycin and tulathromycin. These results show a marked difference in antimicrobial susceptibility of bison isolates as compared with previously reported and laboratory reference cattle isolates, emphasizing the necessity of testing antimicrobial susceptibility of M. bovis bison isolates and to generate better therapeutic regime for improved recovery chances for infected bison herds across North America.

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Mycoplasma bovis in Spanish Cattle Herds: Two Groups of Multiresistant Isolates Predominate, with One Remaining Susceptible to Fluoroquinolones

Pathogens ◽

10.3390/pathogens9070545 ◽

2020 ◽

Vol 9 (7) ◽

pp. 545 ◽

Cited By ~ 2

Author(s):

Ana García-Galán ◽

Laurent-Xavier Nouvel ◽

Eric Baranowski ◽

Ángel Gómez-Martín ◽

Antonio Sánchez ◽

...

Keyword(s):

Dairy Cattle ◽

Inhibitory Concentration ◽

Selective Pressure ◽

Clinical Signs ◽

Economic Losses ◽

Mycoplasma Bovis ◽

Cattle Herds ◽

Detection Of Mutations ◽

Antimicrobial Treatments

Mycoplasma bovis is an important bovine pathogen causing pneumonia, mastitis, and arthritis and is responsible for major economic losses worldwide. In the absence of an efficient vaccine, control of M. bovis infections mainly relies on antimicrobial treatments, but resistance is reported in an increasing number of countries. To address the situation in Spain, M. bovis was searched in 436 samples collected from beef and dairy cattle (2016–2019) and 28% were positive. Single-locus typing using polC sequences further revealed that two subtypes ST2 and ST3, circulate in Spain both in beef and dairy cattle, regardless of the regions or the clinical signs. Monitoring of ST2 and ST3 isolates minimum inhibitory concentration (MIC) to a panel of antimicrobials revealed one major difference when using fluoroquinolones (FQL): ST2 is more susceptible than ST3. Accordingly, whole-genome sequencing (WGS) further identified mutations in the gyrA and parC regions, encoding quinolone resistance-determining regions (QRDR) only in ST3 isolates. This situation shows the capacity of ST3 to accumulate mutations in QRDR and might reflect the selective pressure imposed by the extensive use of these antimicrobials. MIC values and detection of mutations by WGS also showed that most Spanish isolates are resistant to macrolides, lincosamides, and tetracyclines. Valnemulin was the only one effective, at least in vitro, against both STs.

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Antiprotozoal Activity Against Entamoeba histolytica of Flavonoids Isolated from Lippia graveolens Kunth

Molecules ◽

10.3390/molecules25112464 ◽

2020 ◽

Vol 25 (11) ◽

pp. 2464

Author(s):

Ramiro Quintanilla-Licea ◽

Javier Vargas-Villarreal ◽

María Julia Verde-Star ◽

Verónica Mayela Rivas-Galindo ◽

Ángel David Torres-Hernández

Keyword(s):

Entamoeba Histolytica ◽

Inhibitory Concentration ◽

Public Health Problem ◽

In Vitro Tests ◽

Antiprotozoal Activity ◽

Subsequent Work ◽

Antiamoebic Activity ◽

Work Up ◽

First Time

Amebiasis caused by Entamoeba histolytica is nowadays a serious public health problem worldwide, especially in developing countries. Annually, up to 100,000 deaths occur across the world. Due to the resistance that pathogenic protozoa exhibit against commercial antiprotozoal drugs, a growing emphasis has been placed on plants used in traditional medicine to discover new antiparasitics. Previously, we reported the in vitro antiamoebic activity of a methanolic extract of Lippia graveolens Kunth (Mexican oregano). In this study, we outline the isolation and structure elucidation of antiamoebic compounds occurring in this plant. The subsequent work-up of this methanol extract by bioguided isolation using several chromatographic techniques yielded the flavonoids pinocembrin (1), sakuranetin (2), cirsimaritin (3), and naringenin (4). Structural elucidation of the isolated compounds was achieved by spectroscopic/spectrometric analyses and comparing literature data. These compounds revealed significant antiprotozoal activity against E. histolytica trophozoites using in vitro tests, showing a 50% inhibitory concentration (IC50) ranging from 28 to 154 µg/mL. Amebicide activity of sakuranetin and cirsimaritin is reported for the first time in this study. These research data may help to corroborate the use of this plant in traditional Mexican medicine for the treatment of dyspepsia.

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Antifungal activity of thymol against clinical isolates of fluconazole-sensitive and -resistant Candida albicans

Journal of Medical Microbiology ◽

10.1099/jmm.0.008052-0 ◽

2009 ◽

Vol 58 (8) ◽

pp. 1074-1079 ◽

Cited By ~ 50

Author(s):

Na Guo ◽

Jingbo Liu ◽

Xiuping Wu ◽

Xingming Bi ◽

Rizeng Meng ◽

...

Keyword(s):

Candida Albicans ◽

Antifungal Activity ◽

Concentration Index ◽

Inhibitory Concentration ◽

Clinical Isolates ◽

Standard Strain ◽

Antagonistic Action ◽

Microdilution Method ◽

Interaction Intensity

Thymol (THY) was found to have in vitro antifungal activity against 24 fluconazole (FLC)-resistant and 12 FLC-susceptible clinical isolates of Candida albicans, standard strain ATCC 10231 and one experimentally induced FLC-resistant C. albicans S-1. In addition, synergism was observed for clinical isolates of C. albicans with combinations of THY–FLC and THY–amphotericin B (AMB) evaluated by the chequerboard microdilution method. The interaction intensity was determined by spectrophotometry for the chequerboard assay, and the nature of the interactions was assessed using two non-parametric approaches [fractional inhibitory concentration index (FICI) and ΔE models]. The interaction between THY–FLC or THY–AMB in FLC-resistant and -susceptible strains of C. albicans showed a high percentage of synergism by the FICI method and the ΔE method. The ΔE model gave results consistent with FICI, and no antagonistic action was observed in the strains tested.

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In Vitro Interaction of Posaconazole and Caspofungin against Clinical Isolates of Candida glabrata

Antimicrobial Agents and Chemotherapy ◽

10.1128/aac.49.8.3544-3545.2005 ◽

2005 ◽

Vol 49 (8) ◽

pp. 3544-3545 ◽

Cited By ~ 19

Author(s):

E. R. Oliveira ◽

A. W. Fothergill ◽

W. R. Kirkpatrick ◽

B. J. Coco ◽

T. F. Patterson ◽

...

Keyword(s):

Candida Glabrata ◽

Concentration Index ◽

Inhibitory Concentration ◽

Clinical Isolates ◽

Fractional Inhibitory Concentration ◽

Fractional Inhibitory Concentration Index ◽

Fluconazole Resistant ◽

In Vitro Interaction

ABSTRACT Combinations of caspofungin and posaconazole were evaluated by fractional inhibitory concentration index against 119 Candida glabrata isolates. Synergy was seen in 18% of all isolates and in 4% of fluconazole-resistant isolates at 48 h without evidence of antagonism. This antifungal combination may have utility against this organism.

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Antibacterial and Hemolytic Activity of Crotalus triseriatus and Crotalus ravus Venom

Animals ◽

10.3390/ani10020281 ◽

2020 ◽

Vol 10 (2) ◽

pp. 281

Author(s):

Adrian Zaragoza-Bastida ◽

Saudy Consepcion Flores-Aguilar ◽

Liliana Mireya Aguilar-Castro ◽

Ana Lizet Morales-Ubaldo ◽

Benjamín Valladares-Carranza ◽

...

Keyword(s):

Pseudomonas Aeruginosa ◽

Antibacterial Activity ◽

Minimum Inhibitory Concentration ◽

Hemolytic Activity ◽

Inhibitory Concentration ◽

Minimum Bactericidal Concentration ◽

The Other ◽

Medical Treatments ◽

First Time

Rattlesnakes have venoms with a complex toxin mixture comprised of polypeptides and proteins. Previous studies have shown that some of these polypeptides are of high value for the development of new medical treatments. The aim of the present study is to evaluate, in vitro, the antibacterial and hemolytic activity of Crotalus triseriatus and Crotalus ravus venoms. A direct field search was conducted to obtain Crotalus triseriatus and Crotalus ravus venom samples. These were evaluated to determine their antibacterial activity against Escherichia coli, Staphylococcus aureus and Pseudomonas aeruginosa through the techniques of Minimum Inhibitory Concentration (MIC) and Minimum Bactericidal Concentration (MBC). Hemolytic activity was also determined. Antibacterial activity was determined for treatments (Crotalus triseriatus 2) CT2 and (Crotalus ravus 3) CR3, obtaining a Minimum Inhibitory Concentration of 50 µg/mL and a Minimum Bactericidal Concentration of 100 µg/mL against Pseudomonas aeruginosa. CT1 (Crotalus triseriatus 1), CT2, and CR3 presented hemolytic activity; on the other hand, Crotalus ravus 4 (CR4) did not show hemolytic activity. The results of the present study indicate for the first time that Crotalus triseriatus and Crotalus ravus venoms contain some bioactive compounds with bactericidal activity against Pseudomonas aeruginosa which could be used as alternative treatment in diseases caused by this pathogenic bacterium.

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Antileishmanial Effect of 3-Aminooxy-1-Aminopropane Is Due to Polyamine Depletion

Antimicrobial Agents and Chemotherapy ◽

10.1128/aac.01055-06 ◽

2006 ◽

Vol 51 (2) ◽

pp. 528-534 ◽

Cited By ~ 26

Author(s):

Sushma Singh ◽

Angana Mukherjee ◽

Alex R. Khomutov ◽

Lo Persson ◽

Olle Heby ◽

...

Keyword(s):

Biosynthetic Pathway ◽

Leishmania Donovani ◽

Clinical Isolates ◽

Growth And Survival ◽

Antiproliferative Effects ◽

Cell Growth And Differentiation ◽

First Time ◽

Rate Limiting ◽

Sodium Antimony Gluconate

ABSTRACT The polyamines putrescine, spermidine, and spermine are organic cations that are required for cell growth and differentiation. Ornithine decarboxylase (ODC), the first and rate-limiting enzyme in the polyamine biosynthetic pathway, catalyzes the conversion of ornithine to putrescine. As the polyamine biosynthetic pathway is essential for the growth and survival of Leishmania donovani, the causative agent of visceral leishmaniasis, inhibition of the pathway is an important leishmaniacidal strategy. In the present study, we examined for the first time the effects of 3-aminooxy-1-aminopropane (APA), an ODC inhibitor, on the growth of L. donovani. APA inhibited the growth of both promastigotes in vitro and amastigotes in the macrophage model, with the 50% inhibitory concentrations being 42 and 5 μM, respectively. However, concentrations of APA up to 200 μM did not affect the viability of macrophages. The effects of APA were completely abolished by the addition of putrescine or spermidine. APA induced a significant decrease in ODC activity and putrescine, spermidine, and trypanothione levels in L. donovani promastigotes. Parasites were transfected with an episomal ODC construct, and these ODC overexpressers exhibited significant resistance to APA and were concomitantly resistant to sodium antimony gluconate (Pentostam), indicating a role for ODC overexpression in antimonial drug resistance. Clinical isolates with sodium antimony gluconate resistance were also found to overexpress ODC and to have significant increases in putrescine and spermidine levels. However, no increase in trypanothione levels was observed. The ODC overexpression in these clinical isolates alleviated the antiproliferative effects of APA. Collectively, our results demonstrate that APA is a potent inhibitor of L. donovani growth and that its leishmaniacidal effect is due to inhibition of ODC.

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In VitroPhenotypic Susceptibility of HIV-2 Clinical Isolates to CCR5 Inhibitors

Antimicrobial Agents and Chemotherapy ◽

10.1128/aac.05313-11 ◽

2011 ◽

Vol 56 (1) ◽

pp. 137-139 ◽

Cited By ~ 16

Author(s):

Benoit Visseaux ◽

Charlotte Charpentier ◽

Margarita Hurtado-Nedelec ◽

Alexandre Storto ◽

Romain Antoine ◽

...

Keyword(s):

Drug Class ◽

Effective Concentration ◽

Clinical Isolates ◽

Peripheral Blood Mononuclear ◽

Nonnucleoside Reverse Transcriptase Inhibitors ◽

First Time ◽

Ccr5 Inhibitor ◽

Hiv 1 ◽

Median Maximum

ABSTRACTHIV-2 is naturally resistant to nonnucleoside reverse transcriptase inhibitors, to a fusion inhibitor, and to some of the protease inhibitors. Maraviroc is the first drug of the new anti-CCR5 drug class and is effective only on CCR5-tropic (R5) HIV-1. No previous studies concerning HIV-2 susceptibility to maraviroc have been reported yet. We developed a phenotypic maraviroc susceptibility test using a peripheral blood mononuclear cell (PBMC) model. We analyzed the maraviroc susceptibility of 13 R5 HIV-2, 2 X4R5 (dual) HIV-2, and 2 CXCR4-tropic (X4) HIV-2 clinical isolates. We also tested, with the same protocol, 1 X4 HIV-1 and 4 R5 HIV-1 clinical isolates. For the R5 HIV-2 clinical isolates, the 50% effective concentration (EC50) for maraviroc was 0.80 nM (interquartile range [IQR], 0.48 to 1.39 nM), similar to that observed for the R5 HIV-1 isolates. The median maximum percentage of inhibition in the R5 HIV-2 isolates was 93% (IQR, 84 to 98%), similar to that observed in the R5 HIV-1 isolates. As expected, both X4 HIV-1 and HIV-2 were highly resistant to maraviroc. Our study showed for the first time that maraviroc is activein vitroagainst R5 HIV-2. The new tools we developed will allow identification of HIV-2-infected patients eligible for CCR5 inhibitor use and management of virological failure when receiving a maraviroc-based regimen.

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An In Vitro Antibacterial Activity Test of Meniran Herbs’(Phyllanthus Niruri L.) Ethanol ExtractAgainst Mycoplasma gallisepticum causes Chronic Respiratory Disease (CRD) in Broiler Chickens

KnE Life Sciences ◽

10.18502/kls.v3i6.1106 ◽

2017 ◽

Vol 3 (6) ◽

pp. 48 ◽

Cited By ~ 3

Author(s):

Emy Koestanti Sabdoningrum ◽

Sri Hidanah ◽

Retno Sri Wahjuni ◽

Sri Chusniati ◽

Arimbi Arimbi

Keyword(s):

Minimum Inhibitory Concentration ◽

Respiratory Disease ◽

Broiler Chickens ◽

Inhibitory Concentration ◽

Mycoplasma Gallisepticum ◽

Chronic Respiratory Disease ◽

Economic Losses ◽

Dilution Method ◽

Phyllanthus Niruri

Chronic Respiratory Disease (CRD) is a chicken respiratory disease that attacks both broilers and layers. Chronic Respiratory Disease (CRD) has important economic significance in the intensification of chicken farms because this disease can cause huge economic losses. Meniran plant (Phyllanthus niruri Linn) is one of the plants that can be used as prevention and alternative treatment as a substitute of antibiotic caused by Mycoplasma galisepticum causes Chronic Respiratory Disease (CRD) in broiler chickens. The chemicals contained in meniran include tannins, saponins, alkaloids as antibacterials. The purpose of this study is to determine the activity of meniran herbs’ (Phyllanthus Niruri Linn) as antibacterial to eradicate Mycoplasma galisepticum. The method of this study is dilution method which included Minimum Inhibitory Concentration [MIC) and Minimum Bactericidal Concentration (MBC). Minimum Inhibitory Concentration [MIC) was taken by making the concentration of meniran extract as much 65%, 62,5%; 60%; 55%; 50%; 45%; 40%. It was then added Mycoplasma gallisepticum bacteria. The result of this study is Meniran’s activation test on Mycoplasma galisepticum obtained a dose of 62,5% could eradicate Mycoplasma galisepticum causes Chronic Respiratory Disease (CRD) in broiler chickens. Meniran herbs’ (Phyllanthus niruri linn) is effective as antibacterial at concentrations of 30% against Mycoplasma gallisepticum causes Chronic Respiratory Disease (CRD) in broiler chickens. Keywords: Meniran herbs’ (Phyllanthus Niruri Linn), Mycoplasma Galisepticum, Chronic Respiratory Disease (CRD)

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