scholarly journals Estimation of Mycobacterium avium subsp. paratuberculosis Growth Parameters: Strain Characterization and Comparison of Methods

2011 ◽  
Vol 77 (24) ◽  
pp. 8615-8624 ◽  
Author(s):  
Natalia Elguezabal ◽  
Felix Bastida ◽  
Iker A. Sevilla ◽  
Nuria González ◽  
Elena Molina ◽  
...  
Keyword(s):  
Mycobacterium Avium ◽  
Growth Parameters ◽  
Reference Method ◽  
Strain Differences ◽  
Tween 80 ◽  
Single Copy ◽  
Viable Count ◽  
Content Type ◽  
Generation Times ◽  
Wet Weight

ABSTRACTThe growth rate ofMycobacterium aviumsubsp.paratuberculosiswas assessed by different methods in 7H9 medium supplemented with OADC (oleic acid, albumin, dextrose, catalase), Tween 80, and mycobactin J. Generation times and maximum specific growth rates were determined by wet weight, turbidometric measurement, viable count, and quantitative PCR (ParaTB-Kuanti; F57 gene) for 8M. aviumsubsp.paratuberculosisstrains (K10, 2E, 316F, 81, 445, 764, 22G, and OVICAP 49). Strain-to-strain differences were observed in growth curves and calculated parameters. The quantification methods gave different results for each strain at specific time points. Generation times ranged from an average of 1.4 days for viable count and qPCR to approximately 10 days for wet weight and turbidometry. The wet-weight, turbidometry, and ParaTB-Kuanti qPCR methods correlated best with each other. Generally, viability has been assessed by viable count as a reference method; however, due toM. aviumsubsp.paratuberculosisclumping problems and the presence of noncultivableM. aviumsubsp.paratuberculosiscells, we conclude that qPCR of a single-copy gene may be used reliably for rapid estimation ofM. aviumsubsp.paratuberculosisbacterial numbers in a sample.

scholarly journals Detection of Mycobacteria, Mycobacterium avium Subspecies, and Mycobacterium tuberculosis Complex by a Novel Tetraplex Real-Time PCR Assay

2015 ◽  
Vol 53 (3) ◽  
pp. 930-940 ◽  
Author(s):  
Iker A. Sevilla ◽  
Elena Molina ◽  
Natalia Elguezabal ◽  
Valentín Pérez ◽  
Joseba M. Garrido ◽  
...  
Keyword(s):  
Mycobacterium Tuberculosis ◽  
Real Time ◽  
Mycobacterium Avium ◽  
Real Time Pcr ◽  
Simultaneous Detection ◽  
Reference Method ◽  
Clinical Samples ◽  
Dna Amount ◽  
Content Type ◽  
Specificity And Sensitivity

Mycobacterium tuberculosiscomplex,Mycobacterium avium, and many other nontuberculous mycobacteria are worldwide distributed microorganisms of major medical and veterinary importance. Considering the growing epidemiologic significance of wildlife-livestock-human interrelation, developing rapid detection tools of high specificity and sensitivity is vital to assess their presence and accelerate the process of diagnosing mycobacteriosis. Here we describe the development and evaluation of a novel tetraplex real-time PCR for simultaneous detection ofMycobacteriumgenus,M. aviumsubspecies, andM. tuberculosiscomplex in an internally monitored single assay. The method was evaluated using DNA from mycobacterial (n= 38) and nonmycobacterial (n= 28) strains, tissues spiked with different CFU amounts of three mycobacterial species (n= 57), archival clinical samples (n= 233), and strains isolated from various hosts (n= 147). The minimum detectable DNA amount per reaction was 50 fg forM. bovisBCG andM. kansasiiand 5 fg forM. aviumsubsp.hominissuis. When spiked samples were analyzed, the method consistently detected as few as 100 to 1,000 mycobacterial CFU per gram. The sensitivity and specificity values for the panel of clinical samples were 97.5 and 100% using a verified culture-based method as the reference method. The assays performed on clinical isolates confirmed these results. This PCR was able to identifyM. aviumandM. tuberculosiscomplex in the same sample in one reaction. In conclusion, the tetraplex real-time PCR we designed represents a highly specific and sensitive tool for the detection and identification of mycobacteria in routine laboratory diagnosis with potential additional uses.

Effect of rhizobacteria strains on the induction of resistance in barley genotypes against Cochliobolus sativus

2020 ◽  
Vol 13 (2) ◽  
pp. 83-92 ◽  
Author(s):  
A. Adam
Keyword(s):  
Plant Growth ◽  
Pseudomonas Putida ◽  
Growth Parameters ◽  
Disease Incidence ◽  
Dry Weight ◽  
Cochliobolus Sativus ◽  
Resistance Level ◽  
Wet Weight ◽  
Number Of Leaves ◽  
Barley Genotypes

SummaryEnhancement of the resistance level in plants by rhizobacteria has been proven in several pathosystems. This study investigated the ability of four rhizobacteria strains (Pseudomonas putida BTP1 and Bacillus subtilis Bs2500, Bs2504 and Bs2508) to promote the growth in three barley genotypes and protect them against Cochliobolus sativus. Our results demonstrated that all tested rhizobacteria strains had a protective effect on barley genotypes Arabi Abiad, Banteng and WI2291. However, P. putida BTP1 and B. subtilis Bs2508 strains were the most effective as they reduced disease incidence by 53 and 38% (mean effect), respectively. On the other hand, there were significant differences among the rhizobacteria-treated genotypes on plant growth parameters, such as wet weight, dry weight, plant height and number of leaves. Pseudomonas putida BTP1 strain was the most effective as it significantly increased plant growth by 15-32%. In addition, the susceptible genotypes Arabi Abiad and WI2291 were the most responsive to rhizobacteria. This means that these genotypes have a high potential for increase of their resistance against the pathogen and enhancement of plant growth after the application of rhizobacteria. Consequently, barley seed treatment with the tested rhizobacteria could be considered as an effective biocontrol method against C. sativus.

scholarly journals Factors Influencing the Chlorine Susceptibility of Mycobacterium avium, Mycobacterium intracellulare, and Mycobacterium scrofulaceum

2003 ◽  
Vol 69 (9) ◽  
pp. 5685-5689 ◽  
Author(s):  
Joseph O. Falkinham
Keyword(s):  
Growth Rate ◽  
Mycobacterium Avium ◽  
Growth Phase ◽  
Growth Rates ◽  
Growth Stage ◽  
Tween 80 ◽  
Culture Conditions ◽  
C Cells ◽  
Mycobacterium Intracellulare ◽  
Factors Influencing

ABSTRACT The susceptibility of representative strains of Mycobacterium avium, Mycobacterium intracellulare, and Mycobacterium scrofulaceum (the MAIS group) to chlorine was studied to identify factors related to culture conditions and growth phase that influenced susceptibility. M. avium and M. intracellulare strains were more resistant to chlorine than were strains of M. scrofulaceum. Transparent and unpigmented colony variants were more resistant to chlorine than were their isogenic opaque and pigmented variants (respectively). Depending on growth stage and growth rate, MAIS strains differed in their chlorine susceptibilities. Cells from strains of all three species growing in early log phase at the highest growth rates were more susceptible than cells in log and stationary phase. Rapidly growing cells were more susceptible to chlorine than slowly growing cells. The chlorine susceptibility of M. avium cells grown at 30°C was increased when cells were exposed to chlorine at 40°C compared to susceptibility after exposure at 30°C. Cells of M. avium grown in 6% oxygen were significantly more chlorine susceptible than cells grown in air. Chlorine-resistant MAIS strains were more hydrophobic and resistant to Tween 80, para-nitrobenzoate, hydroxylamine, and nitrite than were the chlorine-sensitive strains.

scholarly journals Effective Treatment of Mycobacterium avium subsp. hominissuis and Mycobacterium abscessus Species Infections in Macrophages, Biofilm, and Mice by Using Liposomal Ciprofloxacin

2018 ◽  
Vol 62 (10) ◽  
Author(s):  
James D. Blanchard ◽  
Valerie Elias ◽  
David Cipolla ◽  
Igor Gonda ◽  
Luiz E. Bermudez
Keyword(s):  
Effective Treatment ◽  
Mouse Models ◽  
Mycobacterium Avium ◽  
Nontuberculous Mycobacteria ◽  
Mycobacterium Abscessus ◽  
Content Type ◽  
Number Of Individuals ◽  
Intranasal Instillation

ABSTRACT Nontuberculous mycobacteria (NTM) affect an increasing number of individuals worldwide. Infection with these organisms is more common in patients with chronic lung conditions, and treatment is challenging. Quinolones, such as ciprofloxacin, have been used to treat patients, but the results have not been encouraging. In this report, we evaluate novel formulations of liposome-encapsulated ciprofloxacin (liposomal ciprofloxacin) in vitro and in vivo. Its efficacy against Mycobacterium avium and Mycobacterium abscessus was examined in macrophages, in biofilms, and in vivo using intranasal instillation mouse models. Liposomal ciprofloxacin was significantly more active than free ciprofloxacin against both pathogens in macrophages and biofilms. When evaluated in vivo, treatment with the liposomal ciprofloxacin formulations was associated with significant decreases in the bacterial loads in the lungs of animals infected with M. avium and M. abscessus. In summary, topical delivery of liposomal ciprofloxacin in the lung at concentrations greater than those achieved in the serum can be effective in the treatment of NTM, and further evaluation is warranted.

scholarly journals Nrf2 Regulates Granuloma Formation and Macrophage Activation during Mycobacterium avium Infection via Mediating Nramp1 and HO-1 Expressions

mBio ◽  
2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Masayuki Nakajima ◽  
Masashi Matsuyama ◽  
Mio Kawaguchi ◽  
Takumi Kiwamoto ◽  
Yosuke Matsuno ◽  
...  
Keyword(s):  
Mycobacterium Avium ◽  
Alveolar Macrophages ◽  
Protective Role ◽  
Granuloma Formation ◽  
Host Susceptibility ◽  
Wild Type ◽  
Critical Determinant ◽  
Content Type ◽  
Avium Infection ◽  
Deficient Mice

ABSTRACT Nrf2 is a redox-sensitive transcription factor that is thought to be important in protection against intracellular pathogens. To determine the protective role of Nrf2 in the host defense against Mycobacterium avium complex (MAC), both wild-type and Nrf2-deficient mice were intranasally infected with MAC bacteria. Nrf2-deficient mice were highly susceptible to MAC bacteria compared with wild-type mice. There were no significant changes in the levels of oxidative stress and Th1 cytokine production between genotypes. Comprehensive transcriptome analysis showed that the expressions of Nramp1 and HO-1 were much lower in the infected lungs, and the expression of Nramp1 was especially lower in alveolar macrophages of Nrf2-deficient mice than of wild-type mice. Electron microscopy showed that many infected alveolar macrophages from Nrf2-deficient mice contained a large number of intracellular MAC bacteria with little formation of phagolysosomes, compared with those from wild-type mice. Treatment with sulforaphane, an activator of Nrf2, increased resistance to MAC with increased lung expression of Nramp1 and HO-1 in wild-type mice. These results indicate that Nramp1 and HO-1, regulated by Nrf2, are essential in defending against MAC infection due to the promotion of phagolysosome fusion and granuloma formation, respectively. Thus, Nrf2 is thought to be a critical determinant of host resistance to MAC infection. IMPORTANCE Nontuberculous mycobacteria (NTM) are an important cause of morbidity and mortality in pulmonary infections. Among them, Mycobacterium avium complex (MAC) is the most common cause of pulmonary NTM disease worldwide. It is thought that both environmental exposure and host susceptibility are required for the establishment of pulmonary MAC disease, because pulmonary MAC diseases are most commonly observed in slender, postmenopausal women without a clearly recognized immunodeficiency. However, host factors that regulate MAC susceptibility have not been elucidated until now. This study shows that Nrf2 is a critical regulator of host susceptibility to pulmonary MAC disease by promoting phagolysosome fusion and granuloma formation via activating Nramp1 and HO-1 genes, respectively. The Nrf2 system is activated in alveolar macrophages, the most important cells during MAC infection, as both the main reservoir of infection and bacillus-killing cells. Thus, augmentation of Nrf2 might be a useful therapeutic approach for protection against pulmonary MAC disease.

scholarly journals Draft Genome Sequence of Bacillus sp. Strain IGA-FME-2, Isolated from the Bulk Soil of Soybean (Glycine max L.) in Northeast China

2021 ◽  
Vol 10 (16) ◽  
Author(s):  
Zhenhua Yu ◽  
Sergio de los Santos-Villalobos ◽  
Yansheng Li ◽  
Jian Jin ◽  
Fannie Isela Parra Cota ◽  
...  
Keyword(s):  
Glycine Max ◽  
Draft Genome ◽  
Gc Content ◽  
Single Copy ◽  
Bulk Soil ◽  
23S Rrna ◽  
Protein Coding ◽  
Content Type ◽  
Protein Coding Genes ◽  
Glycine Max L

ABSTRACT Here, we present the draft genome of Bacillus sp. strain IGA-FME-2. This strain was isolated from the bulk soil of soybean (Glycine max L.). Its genome consists of 3,810 protein-coding genes, 44 tRNAs, two 16S rRNAs, and a single copy of 23S rRNA, with a GC content of 46.4%.

scholarly journals In Vitro Activity of Rifamycin Derivatives against Nontuberculous Mycobacteria, Including Macrolide- and Amikacin-Resistant Clinical Isolates

2021 ◽  
Vol 65 (5) ◽  
Author(s):  
Dae Hun Kim ◽  
Su-Young Kim ◽  
Hee Jae Huh ◽  
Nam Yong Lee ◽  
Won-Jung Koh ◽  
...  
Keyword(s):  
Mycobacterium Avium ◽  
Nontuberculous Mycobacteria ◽  
Therapeutic Option ◽  
Vitro Activity ◽  
Clinical Isolates ◽  
Drug Resistant ◽  
In Vitro Activity ◽  
Content Type ◽  
Resistant Disease

ABSTRACT We evaluated the in vitro activity of rifamycin derivatives, including rifampin, rifapentine, rifaximin, and rifabutin, against clinical nontuberculous mycobacteria (NTM) isolates. Of the rifamycin derivatives, rifabutin showed the lowest MICs against all NTM species, including Mycobacterium avium complex, M. abscessus, and M. kansasii. Rifabutin also had effective in vitro activity against macrolide- and aminoglycoside-resistant NTM isolates. Rifabutin could be worth considering as a therapeutic option for NTM disease, particularly drug-resistant disease.

scholarly journals Mutations in the two component regulator systems PmrAB and PhoPQ give rise to increased colistin resistance in Citrobacter and Enterobacter spp.

2020 ◽  
Vol 69 (4) ◽  
pp. 521-529 ◽  
Author(s):  
Matthew E. Wand ◽  
J. Mark Sutton
Keyword(s):  
Growth Rate ◽  
Type Species ◽  
Galleria Mellonella ◽  
Strain Differences ◽  
Fold Increase ◽  
Colistin Resistance ◽  
Content Type ◽  
Link Type ◽  
Carbapenem Resistant ◽  
Individual Strain

Introduction. Colistin is a last resort antibiotic for treating infections caused by carbapenem-resistant isolates. Mechanisms of resistance to colistin have been widely described in Klebsiella pneumoniae and Escherichia coli but have yet to be characterized in Citrobacter and Enterobacter species. Aim. To identify the causative mutations leading to generation of colistin resistance in Citrobacter and Enterobacter spp. Methodology. Colistin resistance was generated by culturing in increasing concentrations of colistin or by direct culture in a lethal (above MIC) concentration. Whole-genome sequencing was used to identify mutations. Fitness of resistant strains was determined by changes in growth rate, and virulence in Galleria mellonella. Results. We were able to generate colistin resistance upon exposure to sub-MIC levels of colistin, in several but not all strains of Citrobacter and Enterobacter resulting in a 16-fold increase in colistin MIC values for both species. The same individual strains also developed resistance to colistin after a single exposure at 10× MIC, with a similar increase in MIC. Genetic analysis revealed that this increased resistance was attributed to mutations in PmrB for Citrobacter and PhoP in Enterobacter , although we were not able to identify causative mutations in all strains. Colistin-resistant mutants showed little difference in growth rate, and virulence in G. mellonella, although there were strain-to-strain differences. Conclusions. Stable colistin resistance may be acquired with no loss of fitness in these species. However, only select strains were able to adapt suggesting that acquisition of colistin resistance is dependent upon individual strain characteristics.

scholarly journals Isolation of Bacteria Capable of Growth with 2-Methylisoborneol and Geosmin as the Sole Carbon and Energy Sources

2011 ◽  
Vol 78 (2) ◽  
pp. 363-370 ◽  
Author(s):  
Lior Guttman ◽  
Jaap van Rijn
Keyword(s):  
Growth Rates ◽  
Carbon Sources ◽  
Rrna Gene ◽  
16S Rrna Gene Sequences ◽  
Removal Rates ◽  
Content Type ◽  
Enrichment Technique ◽  
Generation Times ◽  
Positive Genus

ABSTRACTUsing a relatively simple enrichment technique, geosmin and 2-methylisoborneol (MIB)-biodegrading bacteria were isolated from a digestion basin in an aquaculture unit. Comparison of 16S rRNA gene sequences affiliated one of the three isolates with the Gram-positive genusRhodococcus, while the other two isolates were found to be closely related to the Gram-negative familyComamonadaceae(VariovoraxandComamonas). Growth rates and geosmin and MIB removal rates by the isolates were determined under aerated and nonaerated conditions in mineral medium containing either of the two compounds as the sole carbon and energy source. All isolates exhibited their fastest growth under aerobic conditions, with generation times ranging from 3.1 to 5.7 h, compared to generation times of up to 19.1 h in the nonaerated flasks. Incubation of the isolates with additional carbon sources caused a significant increase in their growth rates, while removal rates of geosmin and MIB were significantly lower than those for incubation with only geosmin or MIB. By fluorescencein situhybridization, members of the generaRhodococcusandComamonaswere detected in geosmin- and MIB-enriched sludge from the digestion basin.

The effects of glucosteroids on experimental cold-induced brain edema.

1971 ◽  
Vol 34 (4) ◽  
pp. 477-487 ◽  
Author(s):  
Robert E. Maxwell ◽  
Don M. Long ◽  
Lyle A. French
Keyword(s):  
Vascular Permeability ◽  
Brain Edema ◽  
Gray Matter ◽  
Dry Weight ◽  
Content Type ◽  
Beneficial Effects ◽  
Primary Reduction ◽  
Wet Weight ◽  
Experimental Brain Edema ◽  
Fine Print

✓ Although the beneficial effects of glucosteroids on brain edema are well documented and generally accepted clinically, investigations into their effects on experimental brain edema have been somewhat contradictory. In this study brain edema was produced by local cortical freezing in animals pretreated with glucosteroids and in untreated animals. Gross estimation of edema, wet weight-dry weight determination, and mechanical planimetry of areas of extravasated dye indicated a statistically significant reduction in edema of both white and gray matter at 24, 48, and 72 hours. Gross estimation of edema indicated a persisting effect with resolution of edema at 5 days in treated animals and from 7 to 12 days in untreated animals. These studies substantiate initial investigations and indicate a primary reduction in brain edema by glucosteroids. At least one of the effects of the glucosteroids appears to be reduction of the abnormal vascular permeability causing brain edema.

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