Molecular analyses of conjugative, gentamicin-resistance plasmids from staphylococcal clinical isolates

1988 ◽  
Vol 34 (9) ◽  
pp. 1050-1057 ◽  
Author(s):  
Ioannis Zorbas ◽  
Robert T. Hall ◽  
Sue L. Hall ◽  
William G. Barnes ◽  
Marvin Rogolsky
Keyword(s):  
Restriction Endonuclease ◽  
Clinical Isolates ◽  
Genetic Determinants ◽  
Conjugative Plasmids ◽  
Molecular Weights ◽  
Geographical Regions ◽  
Gentamicin Resistance ◽  
Ecori Restriction ◽  
High Degree ◽  
Endonuclease Digestion

Gentamicin-resistant Staphylococcus aureus and Staphylococcus epidermidis strains which were isolated from infants with staphylococcal bacteremia were analyzed for the presence of self-transmissible gentamicin-resistance (Gmr) plasmids. Conjugative GMr plasmids of approximately 43.8–63 kilobases (kb) were found in all S. aureus strains. Inter- and intra-species transfer of Gmr plasmids by conjugation was observed from S. aureus to S. aureus and to S. epidermidis recipient strains. However, neither inter- nor intra-species transfer of gentamicin resistance by conjugation was observed with nine out of nine S. epidermidis donor strains which were mated with either S. epidermidis or S. aureus recipient strains. These conjugative Gmr plasmids were unable to comobilize a smaller (15-kb) plasmid present in all but two S. aureus clinical isolates. Many of the conjugative Gmr plasmids also carried genetic determinants for kanamycin, tobramycin, neomycin, and ethidium bromide resistance, and for β-lactamase synthesis. EcoRI restriction endonuclease digests of the S. aureus Gmr conjugative plasmids revealed three different digestion patterns. Four EcoRI restriction endonuclease digestion fragments of 15, 11.4, 6.3, and 4.6 kb in size were common to all plasmids. These plasmids and conjugative Gmr staphylococcal plasmids from other geographical regions shared restriction digestion fragments of similar molecular weights. DNA hybridization with biotinylated S. aureus plasmid pIZ7814 DNA revealed a high degree of homology among these plasmids. A 50.9-kb plasmid from one of the nonconjugative S. epidermidis clinical isolates showed homology with the probe DNA but lacked a portion of a 6.3-kb fragment which was present in all conjugative plasmids and believed to carry much genetic information for conjugation.

scholarly journals Nationwide Temporal and Geographical Distribution of Tick Populations and Phylogenetic Analysis of Severe Fever with Thrombocytopenia Syndrome Virus in Ticks in Korea, 2020

2021 ◽  
Vol 9 (8) ◽  
pp. 1630
Author(s):  
Min-Goo Seo ◽  
Byung-Eon Noh ◽  
Hak Seon Lee ◽  
Tae-Kyu Kim ◽  
Bong-Goo Song ◽  
...  
Keyword(s):  
Tick Species ◽  
Temporal Distribution ◽  
Epidemiological Studies ◽  
Haemaphysalis Longicornis ◽  
Geographical Regions ◽  
Control And Prevention ◽  
Amblyomma Testudinarium ◽  
High Degree ◽  
Severe Fever ◽  
Minimum Infection Rate

Since 2010, the Korea Disease Control and Prevention Agency has established centers at 16 locations to monitor disease vectors and pathogens. Here, we examined tick populations to understand the geographical and temporal distribution of severe fever with thrombocytopenia syndrome virus (SFTSV) vectors in 2020. From April to November, 63,376 ticks were collected from traps to monitor tick populations, with a trap index of 41.3. Tick incidence varied from April to October, with population peaks observed for nymphs in May, adults in July, and larvae in September. The predominant tick species were Haemaphysalis longicornis, Haemaphysalis spp., H. flava, Ixodes spp., Amblyomma testudinarium, and Ixodes nipponensis. Approximately 50% of the collected ticks were pooled into 2973 groups to detect the rate of SFTSV infection in ticks. The minimum infection rate (MIR) of SFTSV was 0.2%, and Andong had the highest MIR for SFTSV (4.0%). The B3 genotype was the most prevalent (52.2%) followed by B2 (28.6%), B5 (15.9%), B4 (1.6%), and B6 (1.6%). We identified widely distributed tick species and a high degree of diversity in SFTSV strains in ticks from different geographical regions. The results may provide a basis for future epidemiological studies and risk assessments for tick-borne diseases.

scholarly journals Antimicrobial Susceptibility Patterns among a Large, Nationwide Cohort of Abiotrophia and Granulicatella Clinical Isolates

2017 ◽  
Vol 55 (4) ◽  
pp. 1025-1031 ◽  
Author(s):  
Kunatum Prasidthrathsint ◽  
Mark A. Fisher
Keyword(s):  
Antimicrobial Susceptibility ◽  
Clinical Isolates ◽  
Broth Microdilution ◽  
Content Type ◽  
Geographical Regions ◽  
Susceptibility Patterns

ABSTRACTAntimicrobial susceptibility patterns from 599A. defectiva,G. adiacens, andG. elegansclinical isolates were determined by broth microdilution. We observed significant differences in susceptibility across species, particularly to penicillin and ceftriaxone, and across geographical regions.A. defectivawas the least susceptible species overall to penicillin. All isolates were susceptible to vancomycin and >90% were susceptible to levofloxacin.

A comparison of the compressibilities of some gases with that of nitrogen at pressures below one atmosphere

1950 ◽  
Vol 200 (1061) ◽  
pp. 201-218 ◽  
Keyword(s):  
Carbon Dioxide ◽  
Differential Method ◽  
Linear Extrapolation ◽  
Volume Changes ◽  
Pure Nitrogen ◽  
Molecular Weights ◽  
Nitrous Oxide Oxygen ◽  
The Individual ◽  
Straight Lines ◽  
High Degree

A differential method for comparing the compressibilities of gases at pressures below 1 atm. has been developed in which many of the errors inherent in methods employed previously have been to a large extent eliminated, especially those due to meniscus volume changes and capillary depression. Using pure nitrogen as a standard the low-pressure isothermals of carbon monoxide, carbon dioxide, nitrous oxide, oxygen, ethylene and propane have been determined at a temperature of 22-05° C. The deviations of the individual points from straight lines do not in most cases exceed 2 parts in 100,000. In no case, even with propane, was any curvature in the isotherms detectable. The contention of Moles and other recent workers that the molecular weights of liquefiable gases can be determined to a high degree of accuracy by linear extrapolation is rendered highly probable by this fresh evidence.

scholarly journals Structures, Locations, and Transfer Frequencies of Genetic Elements Conferring High-Level Gentamicin Resistance in Enterococcus faecalis Isolates in Greece

2003 ◽  
Vol 47 (12) ◽  
pp. 3950-3953 ◽  
Author(s):  
George L. Daikos ◽  
George Bamias ◽  
Christos Kattamis ◽  
Marcus J. Zervos ◽  
Joseph W. Chow ◽  
...  
Keyword(s):  
Enterococcus Faecalis ◽  
Restriction Enzyme ◽  
Plasmid Dna ◽  
Strong Association ◽  
Hybridization Analysis ◽  
Clinical Isolates ◽  
Genetic Elements ◽  
Transfer Characteristics ◽  
Gentamicin Resistance ◽  
High Level

ABSTRACT The elements conferring high-level gentamicin resistance in 64 clinical isolates of Enterococcus faecalis were characterized by PCR and by restriction enzyme hybridization analysis of genomic and plasmid DNA. There was a strong association between gentamicin resistance and the aac(6′)-aph(2") gene carried on IS256-based elements with different structures, locations, and transfer characteristics.

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