Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.1.30.2 (endonuclease)
 18,621 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Acinetobacter calcoaceticus strain BM2500 was resistant to ampicillin, aminoglycoside-aminocyclitols, chloramphenicol, sulfonamides, and high levels of trimethoprim. Resistance to ampicillin was due to the presence of a beta-lactamase (TEM-1) and the aminoglycoside-aminocyclitol resistance was mediated by phosphotransferase (APH(3')(5")I) and adenylyltransferase (AAD(3)(9] activities. The resistance genes were carried by a 167 kilobase plasmid, pIP1031, belonging to incompatibility group 6-C; the plasmid was self-transferable, at extremely low frequency, to Escherichia coli by conjugation. Plasmid pIP1031 DNA was analyzed by agarose gel electrophoresis following restriction endonuclease digestion, by nucleic acid hybridization, and by CsCl analytical density gradient ultracentrifugation. The results support the hypothesis that plasmid pIP1031 may have been acquired recently by strain BM2500.
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PMID:Transferable plasmid-mediated antibiotic resistance in Acinetobacter. 635 87

Characteristics of pBR322/Ad h 1 DNA recombinants were studied which had been cloned using HindIII restriction endonuclease in a single "shot-gun" experiment. Both oxytetracycline and ampicillin resistance of the clones were found to be heterogeneous. Ad h 1 DNA fragments HindIII-A, and -C could be cloned only in combination with other fragments. Among the possible reasons of the loss of recombinants upon transfection the impairment of pBR322-specific gene functions by the inserts is discussed in addition to the increased tetracycline resistance, and the tertiary structure of recombinant DNA.
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PMID:Possible causes of the loss of specific pBR322-Ad h 1 DNA recombinants following transfection. 637 56

A total of 207 strains of Bordetella bronchiseptica isolated from pigs in 1978 and 1979 were tested for drug resistance and for the properties of their R plasmids. Apart from intrinsic resistance to spectinomycin, single (sulfadimethoxine), double (sulfadimethoxine and streptomycin), andt riple (sulfadimethoxine, streptomycin, and ampicillin) resistance were found in 54.1%, 1.0%, and 15.9% of the strains, respectively. All of the triple-resistance determinants were associated with mercury resistance and were conjugative. pBB1, one of these R plasmids, was identified as Fi- (F) and Spp- (no suppression of phage multiplication) type, and as a member of incompatability group IncP. The single- and double-resistance determinants were nonconjugative. pBB2, one of the double-resistance determinants, was mobilized by an R plasmid, RP4, with the high efficiency of 80% and at a frequency of 3.3% without cotransfer of RP4. The molecular weight of pBB1 and pBB2 was estimated at 36 X 10(6) and 13 X 10(6) daltons, respectively, by electron microscopy and agarose gel electrophoresis. pBB1 had five cleavage sites for EcoRI endonuclease, and four sites for HindIII. pBB2 had two EcoRI sites, one HindIII, and one BamHI site. Cells carrying pBB1 or pBB2 produced enzymic activity tha inactivated streptomycin in the presence of ATP.
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PMID:Drug resistance and R plasmids in Bordetella bronchiseptica isolates from pigs. 645 40

A homozygous a2/a2 and b4/b4 rabbit has been hyperimmunized with Micrococcus lysodeikticus. Poly(A)-containing RNA has been isolated from the spleen and translated in vitro, and translation products have been analyzed by NaDodSO4/polyacrylamide gel electrophoresis. Double-stranded cDNA has been synthesized from poly(A)-containing RNA template and inserted in the Pst I endonuclease site of plasmid pBR322 by using the oligo(dC).oligo(dG) tailing procedure. Tetracycline-resistant ampicillin-sensitive clones containing cDNA complementary to a kappa light chain mRNA have been selected by differential screening and their ability to hybridize to a spleen mRNA having the same size as a mouse kappa light chain mRNA. Two clones, pRk-15 and pRk-32, have been selected to determine the nucleotide sequence of the constant and 3' untranslated regions of kappa light chain mRNA, by the Maxam and Gilbert partial degradation method. Comparison of homologous regions of mouse kappa chain mRNA and b4 rabbit kappa chain mRNA reveals 61% homology in the constant region and 59% homology in the 3' untranslated region.
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PMID:Nucleotide sequence of constant and 3' untranslated regions of a kappa immunoglobulin light chain mRNA of a homozygous b4 rabbit. 679 36

The replication origins of viral and complementary strands of bacteriophage M13 DNA are contained within a 507-nucleotide intergenic region of the viral genome. Chimeric plasmids have been constructed by inserting restriction endonuclease fragments of the M13 intergenic region into the plasmid pBR322. Replication of these hybrid plasmids, under conditions not permissive for the plasmid replicon, depends on specific segments of the M13 origin region and on the presence of M13 helper virus. Thus M13-infected polA- Escherichia coli can be transformed to ampicillin resistance by hybrid plasmids that have a functional M13 origin. Cells transformed to drug resistance by plasmids bearing M13 origin sequences contain the duplex chimeric DNA at high copy number but do not accumulate significant amounts of single-stranded plasmid DNA. Rare transducing phages carrying single-stranded chimeric DNA are produced and can be detected by their ability to transduce cells to ampicillin resistance. Plasmids containing a 270-nucleotide fragment from the gene II-proximal half of the intergenic region produce transformants at high frequency under nonpermissive conditions. A central Hae III fragment, Hae III-G, containing the nucleotide sequence coding for the RNA primer for the complementary strand and the nicking site for gene II protein, is sufficient for plasmid replication in M13-infected polA- cells but not for high frequency transformation. Additional sequence information on the gene II side of the Hae III-G fragment is necessary for efficient transformation by the plasmid DNA.
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PMID:Replication of the plasmid pBR322 under the control of a cloned replication origin from the single-stranded DNA phage M13. 693 12

Strains of gentamicin-resistant Serratia marcescens (GRSM) that originated in a crowded neurosurgical close observation unit (COU) became established during a 2.5-year interval at several affiliated hospitals in Charleston, South Carolina. Most patients with GRSM had colonization or infection of the urinary tract associated with indwelling bladder catheters. Infected patients in the COU more often had pyuria and less often received systemic steroids than COU patients not harboring GRSM. However, length of stay, use of urinary catheters, exposure to systemic antibiotics, and exposure to gentamicin were not significantly different between the two groups. Of the strains of GRSM, 92% contained a conjugative 41-megadalton plasmid tht encoded resistance to ampicillin, carbenicillin, tetracycline, kanamycin, gentamicin, and tobramycin and elaborated similar aminoglycoside 3-acetyltransferases. Seven 41-megadalton plasmids from outbreak strains and a 41-megadalton plasmid from a 1973 isolate of GRSM gave identical DNA fragments after restriction endonuclease digestion.
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PMID:Characteristics of Serratia marcescens containing a plasmid coding for gentamicin resistance in nosocomial infections. 701 56

Twenty-seven isolates of Bordetella bronchiseptica were examined for the presence of plasmid DNA. Eleven of the isolates contained plasmids. An attempt was made to correlate the presence of plasmids with resistance to a number of antibiotics or heavy metals or with production of bacteriocins. Eight of the isolates contained a plasmid of approximately 35 megadaltons molecular weight; these isolates were all resistant to 1 mM mercuric chloride. There were no other correlations between plasmid content and any of the phenotypes tested. The plasmids conferring resistance to mercuric chloride were transferred by conjugation to Escherichia coli K-12. The plasmid-bearing isolates were then compared with their isogenic plasmidless parent for resistance to a number of antibiotics. Isolates acquiring the plasmids demonstrated increased resistance to streptomycin and ampicillin, as well as to mercuric chloride. The 8 plasmids were also analyzed by restriction endonuclease digestion.
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PMID:Occurrence and characterization of plasmids in field isolates of Bordetella bronchiseptica. 714 91

Fifty-six heat-labile, enterotoxin-producing (LT+) Escherichia coli isolated from 33 children less than 5 years of age with diarrhoea were analysed for resistance to antibiotics, plasmid contents, and clonal relationships among isolates by ribosomal RNA (rRNA) fingerprinting (ribotyping). Fifty-five (98.2%) of the LT+ isolates were resistant either to tetracycline alone (48.2%) or to tetracycline and one or more other antibiotic, i.e. ampicillin, streptomycin, chloramphenicol, trimethoprim-sulfamethoxazole, or nalidixic acid. Most of the isolates harboured one or more plasmid but antibiotic resistance patterns did not always correlate with particular plasmid patterns. Ribotyping of the isolates using the restriction endonuclease EcoRI revealed a total of 7 different ribotypes, and ribotypes were shared by E. coli isolates with different antibiotic resistant phenotypes. The results indicate that in Bangladesh at least 7 different clones of LT+ E. coli acquired resistance to one or more different antibiotics in various combinations. However, a similar drug resistance pattern was not mediated by the same set of plasmids in all strains. The mechanism for the emergence and spread of antibiotic resistance among E. coli should be investigated further in Bangladesh, where LT+ E. coli is an important agent of early childhood diarrhoea.
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PMID:Antibiotic resistance pattern of heat-labile enterotoxin (LT) producing Escherichia coli isolated from children with diarrhoea in Bangladesh: clonal relationships among isolates with different resistant phenotypes. 750 97

The genetic and biochemical basis of ampicillin resistance amongst the aerobic Gram-negative commensal faecal flora of healthy volunteers in South Africa has been determined. Amongst 608 ampicillin resistant strains isolated from 320 of the participants, 158 were able to transfer their ampicillin resistant determinants into Escherichia coli K-12 J62-2. Iso-electric focusing of the beta-lactamases, extracted from the transconjugants, demonstrated that ampicillin resistance resulted from the presence of the TEM-1, TEM-2 and SHV-1 beta-lactamases in 94.3%, 2.5% and 3.2% of isolates respectively. Endonuclease restriction digests of the plasmids isolated from the transconjugants showed that the beta-lactamase genes were present on a wide variety of plasmid types; 101 distinct plasmid endonuclease restriction patterns were identified. Transferable ampicillin resistance was associated with resistance to other antibiotics at the following frequencies: trimethoprim (48.7%), streptomycin (35.4%), tetracycline (27.2%), spectinomycin (9.5%), chloramphenicol (3.2%) and gentamicin (1.3%). One antibiotic resistance pattern, ampicillin and trimethoprim, predominated (28%). In total, 77.9% of the plasmids conferred resistance to other antibiotics raising the possibility that use of any of these agents, not simply ampicillin, may contribute to the maintenance of resistance genes.
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PMID:Beta-lactam resistance in normal faecal flora from South Africa. 758 64

Genetic analysis of antibiotic-resistant plasmids from 102 serologically defined strains of enteropathogenic Escherichia coli from Nigeria was carried out. All the isolates were screened for susceptibility to antibiotics, and 47 were found resistant to tetracycline. A total of 138 plasmids was isolated by agarose gel electrophoresis. Transformation and conjugation experiments showed that 57.4% of the resistant strains carried R-plasmids ranging in sizes from 2 to 46 x 10(6) daltons. Plasmid-determined resistance to tetracycline, ampicillin and streptomycin was found. Restriction endonuclease analysis of three of the commonest plasmids: p1679, p529 and p1479 revealed relatedness with respect to function and structure. The DNA segment on which TcR gene is located on each of them was identified by cloning into the vector plasmid pGL101. The recombinant plasmids pOADI and pOAD2 gave full expression of TcR gene when transformed into E. coli DHI. Furthermore, the tetracycline-resistant strains were examined for their phenotypic behaviour with respect to tetracycline and its lipophilic analogs.
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PMID:Genetic analysis of tetracycline-resistant plasmids in enteropathogenic Escherichia coli isolated from patients in Nigeria. 765 64


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