Further properties of P-2 R-factors of Pseudomonas aeruginosa and their relationship to other plasmid groups

1975 ◽  
Vol 21 (5) ◽  
pp. 592-605 ◽  
Author(s):  
M. S. Shahrabadi ◽  
L. E. Bryan ◽  
H. M. Van Den Elzen

R-factors of the P-2 (prototype R-factor R931) incompatibility group pf plasmids detected in Pseudomonas are compatible with group P, C, W, and N R-factors which are plasmids that can be transferred to Pseudomonas aeruginosa recipients. Members of the P-2 group (R130, R931) have significant homology by DNA–DNA hybridization. R-factors of the P-group (RP1, RP9) and F-group (R1) exhibited homology with P-2 R-factors but to a lesser extent than R130 with R931. Members of the 1, C, and W groups showed no significant homology with P-2 R-factors. Minicircular DNA of strain 931(R931) was not homologous with R931 DNA. The host range of R931 and R130 is limited mainly to certain Pseudomonas species including P. aeruginosa, P. fluorescens, P. putida, and P. stutzeri. These R-factors could not be transferred at detectable frequencies to any member of the Enterobacteriaceae examined. R-factor-specified pili were strongly suggested by the detection of pili by electron microscopy in R+ but not R− non-piliated mutants of P. aeruginosa strain PA01. The combined properties of R-factors 931 and similar R-factors reported before and in this study strongly support our previous contention that this group of R-factors form a significant new group of plasmids. A classification scheme previously proposed for plasmids occurring in Pseudomonas has been modified and four groups have been specified.

1974 ◽  
Vol 23 (3) ◽  
pp. 239-250 ◽  
Author(s):  
P. M. Chandler ◽  
V. Krishnapillai

SUMMARYR factors have been demonstrated in multiply drug resistant strains of enterobacteria andPseudomonas aeruginosain a Birmingham hospital (Lowburyet al.1969; Ingram, Richmond & Sykes, 1973). A comparative genetic analysis of these R factors has been initiated on the basis of a variety of phenotypic characteristics. This paper describes the properties of R factors derived from strains which could transfer multiple drug resistance to the recipient speciesP. aeruginosa, Escherichia coli, Shigella flexneriandSalmonella typhimurium. Two types of R factor could be recognized phenotypically. The single group 1 R factor, R18–1 which is probably the same as RPl-1 (Ingramet al.1972) was different to the group 2 R factors in many respects, including host range, R factor-specific phage plating, cellular location, drug resistance pattern, and stability. The group 2 R factors were found to be very similar to RPl (Grinstedet al.1972) and R1822 (Olsen & Shipley, 1973) with respect to their wide host range, plating of a sex specific phage, extrachromosomal location, and drug resistance pattern. Compatibility was shown between the group 1 R factor and a group 2 R factor, providing additional evidence for significant genetic differences.


1970 ◽  
Vol 16 (2) ◽  
pp. 207-214 ◽  
Author(s):  
E. S. Anderson ◽  
E. J. Threlfall

SUMMARYAn R factor for ampicillin and streptomycin resistance (AS) was identified inSalmonella enteritidis. The AS factor transferred freely toEscherichia coliK12, but only two of 260 K12(AS) clones from this cross would transfer AS toS. typhimurium, although all lines tested transferred it toS. enteritidisand K12. A study of one of the two exceptional lines“ revealed that it also transferred AS toS. paratyphiB,S. thompsonandS. anatum. The R factor maintained its transferability when cycled between these serotypes and K12. Transfer toS. enteritidis, however, resulted in loss of the ability of AS to transfer to the heterologous serotypes, that is, it apparently became host specific forS. enteritidis. S. paratyphiB andS. anatumalso imposed host specificity on AS, butS. typhimuriumandS. thompsondid not. The R factor would always enterS. enteritidis, whatever its previous salmonella host but, once it had done so, it became specific forS. enteritidis. AS could always transfer to K12, which did not seem to modify its host range. These phenomena are most easily explained by analogy with host-controlled modification of phage. Their possible significance in relation to apparent host specificity of R factors is discussed.


1977 ◽  
Vol 30 (1) ◽  
pp. 21-30 ◽  
Author(s):  
R. J. Pinney ◽  
A. E. Jacob ◽  
R. W. Hedges ◽  
J. T. Smith

SUMMARYThymineless strains ofEscherichia coliC600 were constructred harbouring both an R factor of the N incompatibility group (R46 or R447b) and a compatible plasmid (Plac-of the A-C group or the Iα plasmid R62), which contained a segment of N group DNA. Selection was made for the transferred plasmid and dislodgement phenomena were manifest either as loss of an entire plasmid or as deletions of a region of plasmid DNA. Even after the two R factors had become established as separate replicons, the N group R factor but not the other plasmid exhibited instability.Thymine starvation of strain C600thy(R447b/R62) increased the elimination rate of the N group plasmid R447b but no elimination of R62 was observed. However, thymine starvation of strain C600thy(R46/Plac-) not only increased the rate of elimination of R46 but also increased the rate of loss of Plac-. There was no detectable increase in nuclease activity in unstarved R46/Plac-strains and it is concluded that dislodgement of R46 from these strains is not due to induction of the nuclease that has been proposed to be responsible for the elimination of N group plasmids during thymine starvation.Two variants of Plac-were isolated. These did not dislodge R46 from unstarved R46/Plac-strains and were not lost during thymine starvation even though thymineless elimination of R46 occurred at normal frequency.


1973 ◽  
Vol 113 (2) ◽  
pp. 772-780 ◽  
Author(s):  
Ronald H. Olsen ◽  
Patricia Shipley

2019 ◽  
Vol 9 (01) ◽  
pp. 46-50
Author(s):  
Ashwak B Al-Hashimy ◽  
Huda S Alagely ◽  
Akeel K Albuaji ◽  
Khalid R Majeed

The present study included the collection of 100 samples from various clinical sources for investigating the presence of P. aeruginosa in those sources, the samples have been collected from some hospitals in Baghdad and Hillah city (Al-qassim General Hospital, ,Al-hillah teaching hospital,and Al-hashimya General hospital ) which included wounds, burns, ear and sputum infections. The study was carried out through October 2017 till the end of March 2018. The samples were identified based on the morphological and microscopically characteristics of the colonies when they were culturing or number of culture media as well as biochemical tests, molecular identification were also used as a final diagnostic test for isolates that were positive as they belong to P.aeruginosa bacteria during previous tests based on the OprD gene which has specific sequences for P.aeruginosa bacteria as a detection gene and also consider as virulence factor so it have a synonyms mechanism to antibiotic resistance . The results of the final diagnosis showed that 38 isolates belong to target bacteria were distributed as 18 of burns, 11 isolates of wounds, 6 isolates of ear infection and 3 isolates of sputum, The examination of the sensitivity of all bacterial isolates was done for elected 38 isolation towards the 9 antibiotic by a Bauer - Kirby and the isolates were resistant for a number of antibiotics used such as Ciprofloxacin 65.7%, Norflaxacin 71%, Imipenem 63.1% Meropenem 68.4%, Gentamicin 65.7%, Amikacin 26.3%, Cefepime 68.4%, Ceftazidime 65.7% and Piperacillin 57.8%.Molecular method , All isolates (38) of P. aeruginosa positive for the diagnostic special gene (OprD) genes (100%).


1974 ◽  
Vol 5 (6) ◽  
pp. 547-552 ◽  
Author(s):  
S. Iyobe ◽  
K. Hasuda ◽  
A. Fuse ◽  
S. Mitsuhashi

Plant Disease ◽  
1997 ◽  
Vol 81 (8) ◽  
pp. 901-904 ◽  
Author(s):  
Claudia Goyer ◽  
Carole Beaulieu

Ten Streptomyces isolates from common scab lesions on carrots (Daucus carota) were characterized. Morphological and physiological characterization of the carrot isolates established that they were closely related to S. scabies. DNA-DNA hybridization studies were carried out between DNA from the carrot isolates and DNA from two potato strains belonging to the two genetic clusters of S. scabies. Most of the carrot isolates exhibited a high level of DNA relatedness (average of 90%) to strain EF-54, which belongs to genetic cluster 1 of S. scabies. Three carrot isolates could not be included in either S. scabies genetic cluster 1 or 2. The pathogenicity of six S. scabies isolates from potato or carrot, two isolates of S. caviscabies, and one isolate of S. acidiscabies was determined on potato, carrot, radish, beet, turnip, and parsnip. All S. scabies isolates were pathogenic on carrot and radish, but pathogenicity on beet, parsnip, turnip, and potato was variable. Even though S. acidiscabies and S. caviscabies until now have been isolated only from potato, we demonstrated that isolates of these species also could infect other crops, such as radish, carrot, parsnip, and turnip.


1971 ◽  
Vol 17 (2) ◽  
pp. 169-172 ◽  
Author(s):  
Vilma A. Stanisich ◽  
B. W. Holloway

SUMMARYR factors present inPseudomonas aeruginosastrains of clinical origin can be transferred to other strains ofP. aeruginosaand may act to promote host chromosome transfer. In general, their properties are similar to those R factors in Enterobacteria. The different R factors studied vary with respect to transferability, transfer of specific resistance properties, repressibility, and ability to promote chromosome transfer.


1972 ◽  
Vol 20 (2) ◽  
pp. 239-252 ◽  
Author(s):  
J. M. Robertson ◽  
E. C. R. Reeve

SUMMARYThe resistance levels conferred by the T-determinants in four R-factors to Tetracycline and Minocycline in cells ofEscherichia coliK 12, before and after induction of maximum resistance by treatment with sub-inhibitory concentrations of the drugs, are measured by simple growth-and-challenge tests. The effect of a plasmid TKwhich confers tetracycline resistance on its hostKlebsiella aerogenesis tested in the same way. The five T-determinants fall into a high-level and a low-level group for resistance, the former giving 3- to 4-fold higher resistance in both induced and uninduced cells than the latter. The T-determinants all confer much lower resistance to Minocycline (a tetracycline molecule modified at the C-6 and C-7 positions) than to Tetracycline. The main cause of this difference is that cells carrying a T-determinant exclude Minocycline much less efficiently than Tetracycline, but in addition Minocycline is less effective than Tetracycline in inducing increased resistance. These results are discussed in the light of a model put forward to explain the inducible nature of R-factor resistance to the tetracyclines.


2012 ◽  
Vol 32 (1) ◽  
pp. 142-150 ◽  
Author(s):  
Danila Soares Caixeta ◽  
Thiago Henrique Scarpa ◽  
Danilo Florisvaldo Brugnera ◽  
Dieyckson Osvani Freire ◽  
Eduardo Alves ◽  
...  

The biofilm formation of Pseudomonas aeruginosa and Pseudomonas fluorescens on AISI 304 stainless steel in the presence of reconstituted skim milk under different temperatures was conducted, and the potential of three chemical sanitizers in removing the mono-species biofilms formed was compared. Pseudomonas aeruginosa cultivated in skim milk at 28 °C presented better growth rate (10.4 log CFU.mL-1) when compared with 3.7 and 4.2 log CFU.mL-1 for P. aeruginosa and P. fluorescens cultivated at 7 °C, respectively. Pseudomonas aeruginosa formed biofilm when cultivated at 28 °C. However, only the adhesion of P. aeruginosa and P. fluorescens was observed when incubated at 7 °C. The sodium dichloroisocyanurate was the most efficient sanitizer in the reduction of the adhered P. aeruginosa cells at 7 and 28 °C and those on the biofilm, respectively. The hydrogen peroxide was more effective in the reduction of adhered cells of P. fluorescens at 7 °C.


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