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High-level Resistance (high-level + resistance)
Selected AbstractsSIDEROPHORE PRODUCTION, SERUM RESISTANCE, HEMOLYTIC ACTIVITY AND EXTENDED-SPECTRUM ,-LACTAMASE-PRODUCING KLEBSIELLA SPECIES ISOLATED FROM MILK AND MILK PRODUCTSJOURNAL OF FOOD SAFETY, Issue 3 2007HAN GUNDOGAN ABSTRACT This study aimed at the isolation and identification of Klebsiella spp. from dairy product to establish their public health significance by determining their virulence factors, antibiotic resistance and extended-spectrum ,-lactamase (ESBL). Klebsiella pneumoniae, Klebsiella oxytoca and Klebsiella rhinoscleromatis were identified in 25 (58%), 11 (26%) and 7 (16%) isolates, respectively. A high prevalence of Klebsiella isolates had virulence factors such as siderophore production (63%), serum resistance (32.5%) and hemolytic activity (58%). ESBL - producing Klebsiella spp. was detected in 35% of the isolates. Resistance to the antimicrobial agents tested was found to be much higher in the ESBL-producing Klebsiella spp. than in non-ESBL-producing isolates. All ESBL-producing Klebsiella spp. showed high-level resistance to cephalosporins and monobactams. The majority of the serum resistant, siderophore, hemolysin and ESBL producers were K. pneumoniae. [source] EmtA, a rRNA methyltransferase conferring high-level evernimicin resistanceMOLECULAR MICROBIOLOGY, Issue 6 2001Paul A. Mann Enterococcus faecium strain 9631355 was isolated from animal sources on the basis of its resistance to the growth promotant avilamycin. The strain also exhibited high-level resistance to evernimicin, a drug undergoing evaluation as a therapeutic agent in humans. Ribosomes from strain 9631355 exhibited a dramatic reduction in evernimicin binding, shown by both cell-free translation assays and direct-binding assays. The resistance determinant was cloned from strain 9631355; sequence alignments suggested it was a methyltransferase and therefore it was designated emtA for evernimicin methyltransferase. Evernimicin resistance was transmissible and emtA was localized to a plasmid-borne insertion element. Purified EmtA methylated 50S subunits from an evernimicin-sensitive strain 30-fold more efficiently than those from a resistant strain. Reverse transcription identified a pause site that was unique to the 23S rRNA extracted from resistant ribosomes. The pause corresponded to methylation of residue G2470 (Escherichia coli numbering). RNA footprinting revealed that G2470 is located within the evernimicin-binding site on the ribosome, thus providing an explanation for the reduced binding of the drug to methylated ribosomes. [source] psbA mutation (Asn266 to Thr) in Senecio vulgaris L. confers resistance to several PS II-inhibiting herbicidesPEST MANAGEMENT SCIENCE (FORMERLY: PESTICIDE SCIENCE), Issue 9 2006Kee Woong Park Abstract DNA sequence analysis of the psbA gene encoding the D1 protein of photosystem II (PS II), the target site of PS II-inhibiting herbicides, identified a point mutation (Asn266 to Thr) in a bromoxynil-resistant Senecio vulgaris L. population collected from peppermint fields in Oregon. Although this mutation has been previously reported in Synechocystis, this is the first report of this particular point mutation in a higher plant exhibiting resistance to PS II-inhibiting herbicides. The resistant population displayed high-level resistance to bromoxynil and terbacil (R/S ratio 10.1 and 9.3, respectively) and low-level resistance to metribuzin and hexazinone (R/S ratio 4.2 and 2.6, respectively) when compared with the susceptible population. However, the population was not resistant to the triazine herbicides atrazine and simazine or to the urea herbicide diuron. A chlorophyll fluorescence assay confirmed the resistance levels and patterns of cross-resistance of the whole-plant studies. The resistant S. vulgaris plants produced fewer seeds. Differences in cross-resistance patterns to PS II-inhibiting herbicides and the difference in fitness cost could be exploited in a weed management program. Copyright © 2006 Society of Chemical Industry [source] Microbiology of Normal External Auditory Canal,THE LARYNGOSCOPE, Issue 11 2001David W. Stroman PhD Abstract Objectives To isolate and characterize bacteria and fungi from the healthy ear and to obtain susceptibility profiles on each bacterial isolate. Study Design Prospective. Methods Specimens were collected from the external canals and cerumen of healthy subjects. Species-level identification was obtained by combining phenotypic and genotypic data. End-point minimal inhibitory concentration testing was performed using National Committee for Clinical Laboratory Standards recommended methods. Results One hundred sixty-four subjects were cultured. Seventeen canal and 16 cerumen specimens showed no growth. One hundred forty-eight cerumen specimens yielded 314 organisms, including 23 fungi. One hundred forty-seven canal specimens yielded 310 organisms, including 7 fungi. Of 291 bacteria isolated from cerumen, 99% were Gram-positive. Of 302 bacteria isolated from the canal, 96% were Gram-positive. Staphylococci were 63% of both the cerumen bacteria and the canal bacteria. Coryneforms represented 22% of the bacteria in cerumen and 19% in the canal. Turicellaotitidis was the primary coryneform isolated from both the canal and the cerumen. Streptococci-like bacteria were 10% from the cerumen, 7% from the canal. In both cerumen and canal, Alloiococcusotitis was more than 95% of the streptococci-like bacteria. Fifteen gram-negative organisms were isolated from the canal and cerumen, including four Pseudomonas aeruginosa strains. The percentages of Staphylococcus epidermidis isolates that had high-level resistance (,8 ,g/mL) were as follows: to neomycin, 28% from cerumen and 11% from the canal; to oxacillin, 28% from cerumen and 25% from the canal; and to ofloxacin, 15% from cerumen and 19% from the canal. ConclusionsTurcella otitidis and A. otitidis were present with a much higher frequency than previously described, lending evidence that they be considered normal otic flora. Corynebacterium auris, previously reported only in children, was isolated from normal adults. [source] Clinical impact of antibiotic-resistant Gram-positive pathogensCLINICAL MICROBIOLOGY AND INFECTION, Issue 3 2009H. M. Lode Abstract The European Union's attention to the problem of antibacterial resistance will soon reach a 10-year mark, but the rates of resistance in Gram-positive and Gram-negative bacteria are still increasing. This review focuses on the clinical impact of resistant Gram-positive bacteria on patients. Multiple drug resistance in pneumococcal infections will lead to more treatment failures and higher mortality, which so far have been seen with penicillins and pathogens with high-level resistance. Several studies have demonstrated higher mortality, prolonged length of hospital stay and higher costs associated with methicillin-resistant Staphylococcus aureus infections, in comparison with methicillin-susceptible Staphylococcus aureus infections. Similarly, vancomycin-resistant enterococci bloodstream infections have a negative impact with respect to mortality, length of hospital stay and costs, in comparison with infections due to vancomycin-susceptible enterococci. Several distinctive prophylactic and therapeutic approaches have to be undertaken to successfully prevent the clinical consequences of antibiotic resistance in Gram-positive bacteria. This review addresses the impact of antibiotic-resistant Gram-positive pathogens on clinical outcomes. [source] New phage type among methicillin-resistant Staphylococcus aureus associated with a local outbreak in Belgium during 2002CLINICAL MICROBIOLOGY AND INFECTION, Issue 10 2006C. Wildemauwe Abstract In total, 150 methicillin-resistant Staphylococcus aureus (MRSA) isolates collected during 2002 from a general Belgian hospital were phage-typed at routine test dilution ×,100. The majority (45%) belonged to phage group (J)*, while 10% were classified as a new phage type 29/(42E)/54/(D11)*. The isolates belonging to this new type carried the aac(6,)-aph(2,,) and the aph(3,) aminoglycoside resistance genes and showed high-level resistance to oxacillin. Molecular typing revealed that they belonged to the multiresistant clonal pulsed-field gel electrophoresis (PFGE) type D8. PFGE group D, characterised as genotype ST228-MRSA-I, has been present in Belgian hospitals since 1999. [source] Public health impact of isoniazid-resistant Mycobacterium tuberculosis strains with a mutation at amino-acid position 315 of katG: a decade of experience in The NetherlandsCLINICAL MICROBIOLOGY AND INFECTION, Issue 8 2006H. R. Van Doorn Abstract A previous limited study demonstrated that Mycobacterium tuberculosis isolates with a mutation at amino-acid position 315 of katG (,315) exhibited high-level resistance to isoniazid and were more frequently resistant to streptomycin. In the present study, isoniazid-resistant M. tuberculosis isolates from 8332 patients in The Netherlands (1993,2002) were screened for the ,315 mutation. Isoniazid resistance was found in 592 (7%) isolates, of which 323 (55%) carried ,315. IS6110 restriction fragment length polymorphism analysis showed that ,315 isolates occurred in clusters, suggesting recent transmission, at the same frequency as isoniazid-susceptible isolates. In contrast, other isoniazid-resistant isolates clustered significantly less frequently. ,315 isolates were high-level isoniazid-resistant, streptomycin-resistant and multidrug-resistant significantly more often, and may have a greater impact on public health, than other isoniazid-resistant isolates. [source] Antimicrobial susceptibility of invasive isolates of Streptococcus pneumoniae in IrelandCLINICAL MICROBIOLOGY AND INFECTION, Issue 7 2004P. Clarke Abstract Between January 1999 and June 2002, 646 invasive isolates of Streptococcus pneumoniae were collected in Ireland. MICs of penicillin, ciprofloxacin, cefotaxime, moxifloxacin and linezolid were determined by Etest methodology. Eighty-seven (13.5%) isolates showed intermediate resistance to penicillin, while seven (1.1%) showed high-level resistance. Eighty-seven (13.5%) isolates were resistant to erythromycin, but all isolates were susceptible to cefotaxime, moxifloxacin and linezolid. The prevalence of pneumococcal isolates non-susceptible to penicillin in Ireland is worryingly high, but currently there are alternative agents available to treat invasive infection. [source] | |||||||||||||