scholarly journals Bovine mastitis caused by rapid-growth environmental mycobacteria

2022 ◽  
Vol 53 (5) ◽  
Author(s):  
Luka Cvetnić ◽  
Miroslav Benić ◽  
Željko Cvetnić ◽  
Sanja Duvnjak ◽  
Irena Reil ◽  
...  
Keyword(s):  
Nitrate Reductase ◽  
Rapid Growth ◽  
Mycobacterium Smegmatis ◽  
Iron Uptake ◽  
Tween 80 ◽  
Identical Result ◽  
Rrna Gene ◽  
Mycobacterium Fortuitum ◽  
Diagnostic Systems ◽  
Tellurite Reduction

Rapid-growth mycobacteria were isolated from two cases of cow mastitis with similar clinical appearance and within a narrow time frame. Mycobacteria were isolated on blood esculine agar. The isolated mycobacteria were Gram stained, Ziehl-Nielsen stained and tested for growth at 25°C, 37°C and 42°C, iron uptake, growth on Löwenstein-Jensen (LJ) agar with and without 5% NaCl, arylsulphatase (3 days), tween 80 hydrolysis, tellurite reduction, nitrate reductase and niacin synthesis. Molecular identification was performed using the Mycobacteria GenoType CM and AS tests (Hain Diagnostika, Nehren, Germany). One isolate was additionally sequenced for the hsp65, rpoB, 16S rRNA gene sequence and transcribed spacer sequence (ITS) DNA. Susceptibility testing of isolates was performed on the Sensititre Rapmycol plate (TREK Diagnostic Systems Ltd.) for trimethoprim/sulfamethoxasole, linezolid, ciprofloxacin, imipenem, moxifloxacin, cefepime, cefoxitin, amoxicillin / clavulanic acid, amikacin, ceftriaxone, doxycycline, minocycline, tigecycline, tobramycine and clarythromycine. Gram-positive acid-resistant rods were observed in stained smears. Both strains grew at 25°C, 37°C and 42°C on LJ medium, and on LJ medium containing 5 % NaCl. The conventional biochemical tests for iron uptake, arylsulphatase (3 days), Tween 80 hydrolysis, tellurite reduction and nitrate reductase were positive, while the niacin test was negative. Both isolates were identified by the GenoType Mycobacterium CM as Mycobacterium fortuitum II/ Mycobacterium mageritense, while application of the GenoType Mycobacterium AS kit identified both isolates as belonging to the species Mycobacterium smegmatis. Analysis of the isolate sequences (strain DS) for 16S ribosomal RNA confirmed a 100% identical result with Mycobacterium smegmatis strain INHR2. According to the CLSI criteria, both strains were sensitive to sulfametoxazole/trimethoprim, linezolid, doxicycline, amikacin and tobramycin. The strains differed in their sensitivity to cefoxitim, and both strains were resistant to clarithromycin. There was a strong difference between the isolates in sensitivity toward cefoxitime and tigecycline.

scholarly journals Intrinsic Macrolide Resistance in Mycobacterium smegmatis Is Conferred by a Novel erm Gene, erm(38)

2003 ◽  
Vol 47 (10) ◽  
pp. 3053-3060 ◽  
Author(s):  
Kevin A. Nash
Keyword(s):  
Mycobacterium Smegmatis ◽  
Sequence Data ◽  
Macrolide Resistance ◽  
23S Rrna ◽  
Cross Resistance ◽  
Rrna Gene ◽  
Mycobacterium Fortuitum ◽  
Knockout Mutant ◽  
23S Rrna Gene ◽  
High Level

ABSTRACT High-level, acquired macrolide resistance in mycobacteria is conferred by mutation within the 23S rRNA gene. However, several mycobacteria are naturally resistant to macrolides, including the Mycobacterium smegmatis group and Mycobacterium tuberculosis complex. Thus, the aim of this study was to characterize this resistance. Intrinsic macrolide resistance in M. smegmatis was inducible and showed cross-resistance to lincosamides but not to streptogramin B (i.e., ML resistance). A similar phenotype was found with Mycobacterium microti and macrolide-resistant Mycobacterium fortuitum. A search of the DNA sequence data for M. smegmatis strain mc2155 identified a novel erm gene, erm(38), and expression analysis showed that erm(38) RNA levels increased >10-fold after a 2-h incubation with macrolide. Inducible ML resistance was not expressed by an erm(38) knockout mutant, and complementation of this mutant with intact erm(38) in trans resulted in high-level ML resistance (e.g., clarithromycin MIC of >512 μg/ml). Thus, the results indicate that erm(38) confers the intrinsic ML resistance of M. smegmatis. Southern blot analysis with an erm(38)-specific probe indicated that a similar gene may be present in macrolide-resistant M. fortuitum. This finding, with the presence of the erm(37) gene (Rv1988) in the M. tuberculosis complex, suggests that such genes are widespread in mycobacteria with intrinsic macrolide resistance.

Aerobic degradation 2,4-dinitrotoluene: effect of raw organic wastes and nitrogen amendment

2019 ◽  
Author(s):  
Osekhokhune E Okozide ◽  
Sunday Adekunle Adebusoye ◽  
Oluwafemi Sunday Obayori
Keyword(s):  
Corn Steep Liquor ◽  
Nitrogen Sources ◽  
Tween 80 ◽  
16S Rrna Gene Sequencing ◽  
Organic Wastes ◽  
Rrna Gene ◽  
Nitrogen Amendment ◽  
Rrna Gene Sequencing ◽  
Steep Liquor ◽  
The Cost

Abstract 2,4-Dinitrotoluene (2,4-DNT), a major by-product of the synthesis of 2,4,6- trinitrotoluene, is widely used as a waterproofing, plasticizing and gelatinizing agent in propellants and explosives. Due to its toxicity, the compound is treated as a priority pollutant. Therefore, its removal from contaminated systems is a major focus of research and attention. Contaminated sites in Ibadan, Nigeria were screened for the presence of 2,4,-DNT degrading organisms. The technique of continual enrichment on NACs yielded bacterial isolates able to utilize 2,4-DNT as growth substrate. Based on phenotypic characteristics and 16S rRNA gene sequencing one of the isolates selected for further study was identified as Proteus sp. strain OSES2. Growth of the strain on 2,4-DNT resulted in exponential increase in biomass and complete substrate utilization within 72 h accompanied with NO 3 - elimination. Degradation competence enhanced in the presence of Corn steep liquor, molasses and Tween 80 compared to incubation without amendment. Conversely, amendment with nitrogen sources yielded no significant improvement in degradation. Use of this organism organic wastes as candidates in bioremediation strategy should be exploited. This would provide a cheaper organic source supplement for cleanup purposes with the ultimate aim of reducing the cost of bioremediation while reducing wastes intended for landfill.

scholarly journals 1358. A Novel Rapidly Growing Mycobacteria (RGM) Species Causing Soft Tissue and Orthopedic Hardware Infection After Trauma

2019 ◽  
Vol 6 (Supplement_2) ◽  
pp. S492-S492
Author(s):  
David C Nguyen ◽  
Michelle Lisgaris ◽  
Sruthi Vasireddy ◽  
Richard J Wallace ◽  
Federico Perez ◽  
...  
Keyword(s):  
Soft Tissue ◽  
16S Rrna ◽  
Antibiotic Susceptibility ◽  
Molecular Techniques ◽  
16S Rrna Genes ◽  
Rrna Genes ◽  
Rrna Gene ◽  
Mycobacterium Fortuitum ◽  
Rapidly Growing Mycobacteria ◽  
Maldi Tof

Abstract Background The widespread use of molecular techniques has resulted in increasing numbers of newly characterized rapidly growing mycobacteria (RGM). Many RGM cause soft tissue and orthopedic hardware infection, particularly after trauma. RGM species identification remains challenging with few genetic differences between species. Methods We describe a case involving RGM. We report results of matrix-assisted laser desorption/ionization time of flight (MALDI-TOF) mass spectrometry (Bruker Biotyper), sequencing of rpoB, erm(39), and 16S rRNA genes, and antibiotic susceptibility testing (AST). We review previous reports describing similar RGM infections. Results A 58-year-old male sustained multiple fractures and right thigh compartment syndrome after a motorcycle accident. He underwent fasciotomy and multi-stage surgical fixations. 3 months later, he had wound dehiscence, purulence and multiple fluid collections of his right leg and knee requiring surgical drainage and removal of orthopedic hardware. After 4 days, acid-fast bacilli grew on routine bacterial culture media. MALDI-TOF identified the isolate as Mycobacterium mageritense. In contrast, sequencing of 16S rRNA (100% identity) and erm(39) (> 99% identity) identified the isolate as Mycobacterium houstonense; erm(39) only had 80% similarity with Mycobacterium fortuitum. Sequencing of rpoB showed a 19 bp difference with the M. houstonense type strain, and showed similarity to M. fortuitum (97.64%) than M. houstonense (97.45%). AST demonstrated resistance to clarithromycin only. After initial treatment with imipenem, ciprofloxacin, and doxycycline, definite therapy with ciprofloxacin and doxycycline was successful. In the literature, we found one case each of M. mageritense and M. houstonense infection after trauma. Conclusion This case highlights the importance of RGM other than M. fortuitum as a cause of soft tissue and orthopedic hardware infections, and illustrates the difficulty of identifying them to the species level. Sequencing of erm(39) and 16S rRNA gene identified the isolate as M. houstonense, but the larger difference (>2.5%) in rpoB sequence suggests a novel species. Further characterization is underway. Efforts to determine RGM species and antibiotic susceptibility give important insight into diagnosis and management. Disclosures All authors: No reported disclosures.

scholarly journals Structure-activity relationships of quinolone agents against mycobacteria: effect of structural modifications at the 8 position.

1996 ◽  
Vol 40 (10) ◽  
pp. 2363-2368 ◽  
Author(s):  
T E Renau ◽  
J W Gage ◽  
J A Dever ◽  
G E Roland ◽  
E T Joannides ◽  
...  
Keyword(s):  
Mycobacterium Smegmatis ◽  
Antimycobacterial Activity ◽  
Mycobacterium Fortuitum ◽  
Structural Modifications ◽  
Structure Activity ◽  
Mycobacterium Aurum ◽  
The Relationship ◽  
Tuberculosis Activity ◽  
Better Than ◽  
Positive Controls

A series of quinolones with substitutions at the 8 position has been prepared as part of a study to examine the relationship between structural modifications at this position and activity against mycobacteria. The compounds were prepared by procedures described in the literature and were evaluated for their activities against Mycobacterium fortuitum and Mycobacterium smegmatis. The activities of the compounds against these two organisms were used as a measure of Mycobacterium tuberculosis activity. The results demonstrate that the contribution of the 8 position to antimycobacterial activity was dependent on the substituent at N-1 and was in the order (i) COMe approximately CBr > CCI > CH approximately CF approximately COEt > N > CCF3 when N-1 was cyclopropyl; (ii) N approximately CH > CF > COMe when N-1 was 2,4-difluorophenyl; (iii) N > or = CH when N-1 was tert-butyl; and (iv) N > CH when N-1 was ethyl. In general, derivatives with piperazine substitutions at C-7 were slightly less active against mycobacteria than the analogs with pyrrolidine substitutions, regardless of the pattern of substitution at the 8 position. Several of the best compounds were evaluated for their potential side effects as well as their activities against Mycobacterium aurum, Mycobacterium avium-M. intracellulare, and M. tuberculosis. These agents exhibited biological profiles similar to or better than those of the positive controls ciprofloxacin and sparfloxacin.

scholarly journals Accumulation of Norfloxacin by Mycobacterium aurum and Mycobacterium smegmatis

1998 ◽  
Vol 42 (4) ◽  
pp. 795-800 ◽  
Author(s):  
Kerstin J. Williams ◽  
Gavin A. C. Chung ◽  
Laura J. V. Piddock
Keyword(s):  
Steady State ◽  
Mycobacterium Smegmatis ◽  
Tween 80 ◽  
Proton Motive Force ◽  
Fluorescence Method ◽  
Steady State Concentration ◽  
Silicon Oil ◽  
Wash Buffer ◽  
Mycobacterium Aurum ◽  
State Concentration

ABSTRACT The modified fluorescence method was used to determine the accumulation of norfloxacin by Mycobacterium aurum A+ andMycobacterium smegmatis mc2155. By using an exogenous norfloxacin concentration of 10 μg/ml, a steady-state concentration (SSC) of 160 to 180 ng of norfloxacin/mg of cells was obtained for M. aurum, and an SSC of 120 to 140 ng of norfloxacin/mg of cells obtained for M. smegmatis. For both species of mycobacteria, the SSC was achieved within 5 min. The silicon oil method was investigated and gave higher SSCs than the modified fluorescence method. Further studies on the mechanism of norfloxacin accumulation by M. aurum were performed. An increase in the pH of the wash buffer from 7.0 to 9.0 did not significantly affect the final SSC obtained. Accumulation was nonsaturated over a norfloxacin concentration range of 0 to 100 μg/ml, and the proton motive force inhibitor 2,4-dinitrophenol (1 and 2 mM), whether it was added before or after norfloxacin was added, had no effect on the final SSC obtained. 2,4-Dinitrophenol also had no effect on norfloxacin accumulation by M. smegmatis. Furthermore, norfloxacin accumulation by M. aurum was unaffected by the presence of either Tween 80 or subinhibitory concentrations of ethambutol in the growth medium. Therefore, it is proposed that norfloxacin accumulation by mycobacteria occurs by simple, energy-independent diffusion.

scholarly journals Taxonomic variation in the Mycobacterium fortuitum third biovariant complex: description of Mycobacterium boenickei sp. nov., Mycobacterium houstonense sp. nov., Mycobacterium neworleansense sp. nov. and Mycobacterium brisbanense sp. nov. and recognition of Mycobacterium porcinum from human clinical isolates

2004 ◽  
Vol 54 (5) ◽  
pp. 1653-1667 ◽  
Author(s):  
Mark F. Schinsky ◽  
Roger E. Morey ◽  
Arnold G. Steigerwalt ◽  
Michael P. Douglas ◽  
Rebecca W. Wilson ◽  
...  
Keyword(s):  
Gene Sequence ◽  
Respiratory Infections ◽  
Restriction Analysis ◽  
Rrna Gene ◽  
Mycobacterium Fortuitum ◽  
Genetic Groups ◽  
Gene Sequence Analysis ◽  
Pcr Rflp ◽  
Disseminated Disease ◽  
Type Strains

The Mycobacterium fortuitum third biovariant complex (sorbitol-negative and sorbitol-positive) contains unnamed taxa first characterized in 1991. These organisms can cause respiratory infections, a spectrum of soft tissue and skeletal infections, bacteraemia and disseminated disease. To evaluate this group of organisms, clinical reference isolates and the type strains of M. fortuitum third biovariant complex sorbitol-negative (n=21), M. fortuitum third biovariant complex sorbitol-positive (n=3), M. fortuitum (n=3), Mycobacterium peregrinum (pipemidic acid-susceptible) (n=1), Mycobacterium porcinum (n=1), Mycobacterium senegalense (n=2) and Mycobacterium septicum (n=1) were characterized by using conventional phenotypic (morphological, physiological and antimicrobial susceptibilities), chemotaxonomic (HPLC and cellular fatty acids) and genotypic [RFLP of the rRNA gene (ribotyping), PCR-RFLP of a 439 bp segment of the 65 kDa hsp gene (PCR restriction analysis) and 16S rRNA gene sequence] analysis, DNA G+C content and DNA–DNA relatedness analyses. The results of these studies indicated that the strains comprised M. porcinum (n=13), M. septicum (n=1) and four novel closely related genetic groups within the M. fortuitum third biovariant complex: Mycobacterium boenickei sp. nov. (n=6), Mycobacterium houstonense sp. nov. (n=2), Mycobacterium neworleansense sp. nov. (n=1) and Mycobacterium brisbanense sp. nov. (n=1), with type strains ATCC 49935T (=W5998T=DSM 44677T), ATCC 49403T (=W5198T=DSM 44676T) ATCC 49404T (=W6705T=DSM 44679T) and ATCC 49938T (=W6743T=DSM 44680T), respectively.

scholarly journals Sulfitobacter delicatus sp. nov. and Sulfitobacter dubius sp. nov., respectively from a starfish (Stellaster equestris) and sea grass (Zostera marina)

2004 ◽  
Vol 54 (2) ◽  
pp. 475-480 ◽  
Author(s):  
Elena P. Ivanova ◽  
Nataliya M. Gorshkova ◽  
Tomoo Sawabe ◽  
Natalia V. Zhukova ◽  
Karin Hayashi ◽  
...  
Keyword(s):  
Zostera Marina ◽  
Novel Species ◽  
Tween 80 ◽  
Rrna Gene ◽  
16S Rrna Gene Sequences ◽  
Gram Negative ◽  
Sea Grass ◽  
Total Fatty Acids ◽  
Type Strains ◽  
Phenotypic And Genotypic Characterization

On the basis of data from phenotypic and genotypic characterization and analysis of 16S rRNA gene sequences, two novel species belonging to the genus Sulfitobacter are described. Strains KMM 3584T, a pale-yellowish, non-motile strain isolated from a starfish (Stellaster equestris), and KMM 3554T, which is motile by means of a single subpolar flagellum and was isolated from sea grass (Zostera marina), are marine, Gram-negative, aerobic, rod-shaped organisms. Both strains have the ability to degrade gelatin, but not casein, chitin, agar, DNA, Tween 80 or starch. Strain KMM 3584T decomposed alginate and grew at NaCl concentrations of 1–8 % and temperatures of 12–37°C, whereas strain KMM 3554T grew in 1–12% NaCl and at temperatures of 10–30°C. The predominant fatty acid was 18:1ω7, amounting to up to 80% of the total fatty acids. The other characteristic feature was the presence of 18:2 isomers. The DNA G+C contents of KMM 3584T and KMM 3554T were respectively 60·0 and 63·7 mol%. The level of DNA similarity between the two strains was 33%. DNA from KMM 3584T and KMM 3554T had hybridization values of 5–24% and 10–41%, respectively, with DNA from the type strains of Sulfitobacter pontiacus, Sulfitobacter brevis, Sulfitobacter mediterraneus and Staleya guttiformis. It is proposed that strains KMM 3584T (=LMG 20554T=ATCC BAA-321T) and KMM 3554T (=LMG 20555T=ATCC BAA-320T) represent two novel species, Sulfitobacter delicatus sp. nov. and Sulfitobacter dubius sp. nov., respectively.

Lysogeny in mycobacteria. I. Conversion of colony morphology, nitrate reductase activity, and Tween 80 hydrolysis of Mycobacterium sp. ATCC 607 associated with lysogeny

1968 ◽  
Vol 14 (5) ◽  
pp. 551-555 ◽  
Author(s):  
Wilbur Jones ◽  
Arthur White
Keyword(s):  
Nitrate Reductase ◽  
Nitrate Reductase Activity ◽  
Reductase Activity ◽  
Tween 80 ◽  
Rapid Loss ◽  
Colony Type ◽  
Rough Strain ◽  
Hydrolytic Activities ◽  
Multiple Characteristics ◽  
Hydrolysis Of

Colony changes from rough to smooth were observed in a rough strain of mycobacterium ATCC 607 after exposure to phages D29 and B4. The colonies surviving after exposure to these two phages were both smooth and lysogenic. Increased nitrate reductase and Tween 80 hydrolytic activities accompanied lysogenization. Loss of lysogeny was accompanied by conversion to the rough colony type and a decrease in nitrate reductase and Tween 80 hydrolytic activities. The rapid loss and gain of these multiple characteristics suggested that the genetic control lies in a plasmid of mycobacteria.

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