ABSTRACT
The incidence of the epidemic methicillin-resistant Staphylococcus aureus (EMRSA) strains EMRSA-15 and EMRSA-16 in Scotland has increased dramatically, now accounting for c. 70% and c. 20% of isolates, respectively. Epidemiological tracking of these EMRSA strains is difficult, as c. 50% of EMRSA-15 and c. 35% of EMRSA-16 isolates are indistinguishable using pulsed-field gel electrophoresis (PFGE) and other typing methods. The usefulness of mec-associated direct repeat unit (dru) sequence analysis as a more sensitive approach to tracking the persistence and spread of these 'clonal' EMRSA strains in Scotland was evaluated. Analysis of 47 EMRSA-15 and 57 EMRSA-16 isolates (including two separately cultured isolates of the Harmony collection type strain) obtained from 22 hospital laboratories over an 8-year period (1997-2005) revealed 13 and 12 different dru types, respectively. Whereas some types appeared to be endemic in multiple hospitals, subtypes that may represent specific strain movement among hospitals in a given geographical region were identified in other instances. These results suggest that mec-associated dru typing may have potential for identifying and tracking specific subtypes of otherwise indistinguishable epidemic MRSA isolates such as those in Scotland.
Subject(s)
Bacterial Typing Techniques , DNA, Bacterial/genetics , Methicillin Resistance , Repetitive Sequences, Nucleic Acid , Staphylococcal Infections/microbiology , Staphylococcus aureus/classification , Staphylococcus aureus/genetics , Base Sequence , Genotype , Humans , Molecular Epidemiology , Molecular Sequence Data , Scotland/epidemiology , Sequence Alignment , Staphylococcal Infections/epidemiology , Staphylococcus aureus/drug effects , Staphylococcus aureus/isolation & purificationABSTRACT
The purpose of the study was the molecular characterization of methicillin-resistant Staphylococcus aureus (MRSA) isolates cultured from patients treated in seven wards of a university hospital in Lublin, Poland, over a 14-month period. Eleven nosocomial MRSA isolates were analyzed. Phenotypic identification of the isolates as MRSA was confirmed by the detection of the nuc and mecA genes using a multiplex PCR assay. The MRSA isolates were further characterized by pulsed-field gel electrophoresis, 16S-23S rRNA spacer length polymorphism analysis, and the simplex and multiplex SCCmec PCR assays. The MRSA isolates were found to be multiresistant: in addition to resistance to beta-lactam agents, they demonstrated resistance to ciprofloxacin, tetracycline, erythromycin, and gentamicin. The MRSA isolates were genetically identical and shared common pulsed-field gel electrophoresis profiles and 16S-23S rRNA spacer length polymorphism profiles. The PCR-based method revealed that the profile of the Lublin clone was identical to that of the Brazilian pandemic MRSA isolates. By SCCmec typing, all MRSA isolates harbored the C variant of the SCCmec type III that differed from the typical SCCmec type III pattern by the lack of locus F (414 bp). The results of this study indicate the spread of a single, multiresistant, MRSA clone in various wards of a university hospital over a 14-month period. The SCCmec structure harbored by the Lublin clone has previously been identified among Polish MRSA isolates representing the HoMRSA-Pol1 clone. The data from this study indicate that the Lublin MRSA clone is most probably genetically related to the HoMRSA-Pol1 clone. Moreover, this latter clone belongs to ST239, the same sequence type as the Hungarian and Brazilian pandemic MRSA isolates.
Subject(s)
Bacterial Proteins/genetics , Cross Infection/microbiology , Disease Outbreaks , Endonucleases/genetics , Micrococcal Nuclease/genetics , Staphylococcal Infections/genetics , Staphylococcus aureus/drug effects , Staphylococcus aureus/genetics , Bacterial Typing Techniques , Cross Infection/epidemiology , Drug Resistance, Multiple/genetics , Drug Resistance, Multiple, Bacterial , Electrophoresis, Gel, Pulsed-Field , Hospitals, University , Humans , Methicillin Resistance/drug effects , Methicillin Resistance/genetics , Penicillin-Binding Proteins , Poland/epidemiology , RNA, Ribosomal, 16S , Staphylococcus aureus/pathogenicitySubject(s)
Anti-Infective Agents, Local/pharmacology , Methicillin Resistance/drug effects , Microbial Sensitivity Tests , Oral Hygiene/methods , Staphylococcus aureus/drug effects , Humans , Methicillin Resistance/physiology , Microbial Sensitivity Tests/methods , Mouthwashes/pharmacology , Staphylococcus aureus/growth & development , Toothpastes/pharmacologySubject(s)
Infection Control , Staphylococcal Infections/prevention & control , Staphylococcus , Community-Acquired Infections/prevention & control , Humans , Methicillin Resistance , Staphylococcal Infections/epidemiology , Staphylococcus/drug effects , Staphylococcus/genetics , Staphylococcus/pathogenicity , Vancomycin/therapeutic useABSTRACT
plQ5 plasmid consists of a group of genes specifying resistance to ampicillin, chloramphenicol, carbencillin, kanamycin and trimethoprim-sulphamethoxazole. It is isolated inKlebslella pneumoniae ZD532, is about 26.8 Kb and is freely transmissible to various bacterial species of Gram-negative bacteria. Physical characterization revealed that plQ5 plasmid has a single site forHindill,BamHI,EcoRI and two sites forBglII restriction enzyme.
ABSTRACT
After the 1972 mercury poisoning in Iraq, there was widespread concern over the use of mercury fungicides in seed dressing. The ethyl mercury fungicide Ceresan M, claimed to be responsible for the two earlier outbreaks of poisoning in 1956 and 1960 in Iraq, was tested in Drosophila to study its mutagenic potentialities. Of the two concentrations used, namely 30 and 40 mg of the chemical in 100 cc of the food medium, the latter treatment resulted in a significant increase in the frequency of sex-linked recessive lethals.
