Epidemiological investigation of fluoroquinolone resistance in infections due to extended-spectrum beta-lactamase-producing Escherichia coli and Klebsiella pneumoniae.
(9/3396)
The incidence of infections due to extended-spectrum beta-lactamase (ESBL)-producing Escherichia coli and Klebsiella pneumoniae (ESBL-EK) has increased markedly in recent years. Treatment is difficult because of frequent multidrug resistance. Although fluoroquinolones offer effective therapy for ESBL-EK infections, their usefulness is threatened by increasing fluoroquinolone resistance. To identify risk factors for fluoroquinolone resistance in ESBL-EK infections, a case-control study of all patients with ESBL-EK infections from 1 June 1997 through 30 September 1998 was conducted. Of 77 ESBL-EK infections, 43 (55.8%) were resistant to fluoroquinolones. Independent risk factors for fluoroquinolone resistance were fluoroquinolone use (odds ratio [OR], 11.20; 95% confidence interval [CI], 1.99-63.19), aminoglycoside use (OR, 5.83; 95% CI, 1.12-30.43), and long-term care facility residence (OR, 3.39; 95% CI, 1.06-10.83). The genotypes of fluoroquinolone-resistant ESBL-EK isolates were closely related. Efforts should be directed at modification of these risk factors to preserve the utility of fluoroquinolones in the treatment of ESBL-EK infections. (+info)
Rapid identification and antibiotic susceptibility testing of Salmonella enterica serovar Typhi isolated from blood: implications for therapy.
(10/3396)
The turnaround time (TAT) for Salmonella enterica serovar Typhi identification and reporting of the antibiotic susceptibility profile was determined for 391 cases of typhoid fever, using the lysis direct plating or lysis centrifugation method of blood culture along with rapid antimicrobial susceptibility testing. The TAT was more rapid (TAT for 90% of the patients [TAT(90)] = 30 h; TAT(100) +info)
Methicillin-resistant, quinupristin-dalfopristin-resistant Staphylococcus aureus with reduced sensitivity to glycopeptides.
(11/3396)
Of 3,052 Staphylococcus aureus strains collected by the European SENTRY surveillance study, 35 were found to be nonsusceptible to quinupristin-dalfopristin (MIC of > or =2 mg/liter). These isolates originated from four hospitals in France and one in Spain. In isolates from two Parisian hospitals exhibiting the same SmaI macrorestriction pattern, streptogramin resistance was based on vatA and vgbA. One isolate from a hospital in Lyon and 22 from a hospital in Lille were of the vatB vgaB streptogramin A resistance genotype and possessed ermA and/or ermC. As deduced from the loss of either streptogramin A or streptogramin B resistance determinants in particular isolates, resistance to quinupristin-dalfopristin requires mechanisms conferring resistance to both compounds. The SmaI macrorestriction patterns of strains from hospitals in Lille and Lyon were different; however, similarity analysis suggested a relatedness of 20 methicillin-resistant S. aureus strains from the Lille hospital, a finding confirmed by PCR typing based on three different genomic polymorphisms. These groups of isolates were found to be hetero-glycopeptide-intermediate susceptible S. aureus. Information about the failure of glycopeptide chemotherapy has not been available. (+info)
Epidemiology and susceptibility of 3,051 Staphylococcus aureus isolates from 25 university hospitals participating in the European SENTRY study.
(12/3396)
A total of 3,051 methicillin-susceptible Staphylococcus aureus (MSSA) isolates and methicillin-resistant S. aureus (MRSA) isolates in Europe were compared. MRSA isolates constituted 25% of all isolates and were more prevalent in southern Europe. MRSA isolates appeared to be more prevalent in intensive care units than in outpatient departments. Only a small minority of MSSA isolates were multidrug resistant, whereas the majority of MRSA isolates were multidrug resistant. (+info)
Contamination of the clinical microbiology laboratory with vancomycin-resistant enterococci and multidrug- resistant Enterobacteriaceae: implications for hospital and laboratory workers.
(13/3396)
We surveyed environmental surfaces in our clinical microbiology laboratory to determine the prevalence of vancomycin-resistant enterococci (VRE) and multidrug-resistant Enterobacteriaceae (MDRE) during a routine working day. From a total of 193 surfaces, VRE were present on 20 (10%) and MDRE were present on 4 (2%) of the surfaces tested. In a subsequent survey after routine cleaning, all of the 24 prior positive surfaces were found to be negative. Thus, those in the laboratory should recognize that many surfaces may be contaminated by resistant organisms during routine processing of patient specimens. (+info)
The lactococcal secondary multidrug transporter LmrP confers resistance to lincosamides, macrolides, streptogramins and tetracyclines.
(14/3396)
The active efflux of toxic compounds by (multi)drug transporters is one of the mechanisms that bacteria have developed to resist cytotoxic drugs. The authors describe the role of the lactococcal secondary multidrug transporter LmrP in the resistance to a broad range of clinically important antibiotics. Cells expressing LmrP display an increased resistance to the lincosamide, streptogramin, tetracycline and 14- and 15-membered macrolide antibiotics. The streptogramin antibiotic quinupristin, present in the fourth-generation antibiotic RP 59500, can inhibit LmrP-mediated Hoechst 33342 transport, but is not transported by LmrP, indicating that quinupristin acts as a modulator of LmrP activity. LmrP-expressing Lactococcus lactis cells in which a proton-motive force is generated accumulate significantly less tetracycline than control cells without LmrP expression. In contrast, LmrP-expressing and control cells accumulate equal amounts of tetracycline in the absence of metabolic energy. These findings demonstrate that the increased antibiotic resistance in LmrP-expressing cells is a result of the active extrusion of antibiotics from the cell. (+info)
The problem with cephalosporins.
(15/3396)
The cephalosporin antibiotics have become a major part of the antibiotic formulary for hospitals in affluent countries. They are prescribed for a wide variety of infections every day. Their undoubted popularity relies upon lesser allergenic and toxicity risks as well as a broad spectrum of activity. It is the latter feature, however, that encourages the selection of microorganisms that are resistant to these agents. There are long-term implications for the treatment and control of this heterogeneous group of superinfections. When clinicians evaluate a septic patient, it is understandable that they choose empirical therapy with a cephalosporin whilst awaiting microbiology and other tests, since bacterial identification and antimicrobial testing still usually require 24-48 h. The broad-spectrum capability of these drugs, however, encourages rapid overgrowth of some microorganisms that are neither eliminated nor inhibited by therapy. These organisms not only have pathogenic potential, they may also be multiply resistant to antibiotics. This review discusses the evidence that cephalosporin usage is the most important factor in the selection and propagation of microorganisms such as Clostridium difficile, methicillin-resistant Staphylococcus aureus, penicillin-resistant pneumococci, multiply resistant coliforms and vancomycin-resistant enterococci, the continuing increase of which threatens the future of antimicrobial therapy. (+info)
Fluoroquinolone susceptibilities of efflux-mediated multidrug-resistant Pseudomonas aeruginosa, Stenotrophomonas maltophilia and Burkholderia cepacia.
(16/3396)
The antibacterial activities of seven fluoroquinolones (ciprofloxacin, BAYy3118, clinafloxacin, gemifloxacin, moxifloxacin, sparfloxacin and trovafloxacin) against isogenic efflux-mediated multidrug-resistant strains of Pseudomonas aeruginosa, Stenotrophomonas maltophilia and Burkholderia cepacia, were compared. The results indicate that these fluoroquinolones are all substrates for the multidrug efflux systems of these organisms. Clinafloxacin was found generally to be the most active agent against multidrug-resistant strains. (+info)