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F J Schmitz

Publications and source records attributed to F J Schmitz.

At least 19 recordsLinked to original sources
PubMed2004

Beta-lactam susceptibilities and prevalence of ESBL-producing isolates among more than 5000 European Enterobacteriaceae isolates.

In vitro susceptibility to 15 beta-lactam antibiotics was evaluated using Enterobacteriaceae isolated during the SENTRY Antimicrobial Surveillance Program. Piperacillin/tazobactam was the most active penicillin against Escherichia coli, Proteus mirabilis, Klebsiella oxytoca and Klebsiella pneumoniae (94.9%, 98.3%, 87.4% and 82.9% of isolates susceptible). Of the cephalosporins, cefepime was most effective against Escherichia coli, Proteus mirabilis and Enterobacter cloacae (99.2%, 96.3% and 95.2% of isolates susceptible, respectively) and cefoxitin against Klebsiella oxytoca and Klebsiella pneumoniae (98.6% and 95.6% of isolates susceptible). Carbapenems had excellent activity (> or =99.5% of all isolates). ESBL-production was confirmed with the ESBL-Etest and disk diffusion test in 1.3% of Escherichia coli isolates, 18.4% of Klebsiella pneumoniae, 12.6% of Klebsiella oxytoca and 5.3% of Proteus mirabilis isolates.

Aztreonam↗
PubMed2003

Fluoroquinolones: structure and target sites.

The quinolones are a potent group of drugs that target the essential bacterial enzymes DNA gyrase and topoisomerase IV. DNA gyrase is the primary target of Gram negative organisms however, it is topoisomerase IV that is the primary target of Gram positive organisms. Within these enzymes is a highly conserved region centered round the active site where resistance mutations occur. These mutations are almost always identical, irrespective of organism. In spite of the homology of this region, amino acid sequence analysis shows that there are defined differences between the Gram groups, particularly in topoisomerase IV, and it is speculated that herein lies the origin of target preference. Since the first quinolone nalidixic acid was developed, the quinolones have undergone structural modifications, in particular the addition of a fluorine at position 6, to produce the fluoroquinolones. This has seen their potency and pharmakokinetic profile greatly increase. In vitro selection of resistance mutations has allowed the observation of how resistance is acquired and some of the modifications in newer fluoroquinolones have resulted in the shift of primary target from topoisomerase IV to gyrase with Gram positives. Curiously, purified topoisomerase IV is still more sensitive even if gyrase is the primary target. Gyrase remains the primary target for Gram negatives.

Amino Acid Sequence↗
PubMed2002

Three cases of bacterial meningitis after spinal and epidural anesthesia.

During a 3-year period, three cases of bacterial meningitis developing after spinal or epidural anesthesia were observed at one hospital in Germany. The causative organisms were Streptococcus salivarius (2 cases) and Staphylococcus aureus (1 case). In the first two cases, contamination of the needle by oropharyngeal flora of the anesthesiological team was likely but remained unproven. In the third case, a nasal swab obtained from the operating anesthesiologist yielded a Staphylococcus aureus strain whose genotypic profile was identical to that of the patient's strain. Infection control procedures for spinal anesthesia are discussed.

Adult↗
PubMed2002

mecA gene is widely disseminated in Staphylococcus aureus population.

Methicillin-resistant Staphylococcus aureus (MRSA) is one of the most important causes of hospital infections worldwide. High-level resistance to methicillin is caused by the mecA gene, which encodes an alternative penicillin-binding protein, PBP 2a. To determine the clonal relationships between methicillin-susceptible S. aureus (MSSA) and MRSA, we typed 1,069 S. aureus isolates (493 MSSA isolates and 576 MRSA isolates), collected mainly in North American and European hospitals between the 1960s and the year 2000, using pulsed-field gel electrophoresis and ribotyping. Of 10 widespread S. aureus lineages recognized, 8 had corresponding mecA-positive strains. Multiresistant MRSA strains are found in hospitals worldwide, while unrelated and more susceptible strains represent less than 1% of the MRSA population. This supports the hypothesis that horizontal transfer plays an important role in the dissemination of the mecA gene in the S. aureus population.

Bacterial Proteins↗
PubMed2002

Therapeutic options in an era of decreasing antimicrobial susceptibility.

Antimicrobial resistance among human pathogens has evolved to the multidrug-resistant phase. Consequently, preserving antimicrobial efficacy is now an important clinical consideration when selecting an agent for therapy. A new, in vitro measure of potency called the mutant prevention concentration (MPC) allows clinicians to select antibacterials on the basis of an agent's ability to restrict the selection of resistant mutants. With some pathogens, C-8-methoxy fluoroquinolones are expected to be quite effective at restricting the selection of resistance because the value of MPC is below the human serum drug concentration achieved with standard doses. Clinical trials are now needed to determine how well preclinical profiles of these drugs correlate with the prevention of resistance.

Anti-Bacterial Agents↗
PubMed2001

In-vivo transfer of mecA DNA to Staphylococcus aureus [corrected].

Staphylococcus aureus is thought to have acquired mecA DNA by horizontal transfer. DNA fingerprints made by restriction nucleases that cut certain sequences of DNA are used to compare complete genomes or particular genes between bacteria. We isolated an epidemic mecA(-) meticillin-susceptible S aureus genotype and, subsequently, a rare isogeneic mecA(+) meticillin-resistant S aureus (MRSA) genotype from a neonate who had never been in contact with MRSA. This MRSA contained mecA DNA that was identical to that in a coagulase-negative staphylococcal strain isolated from this patient, but different from other MRSA genotypes. We believe that this MRSA was formed in vivo by horizontal transfer of the mecA DNA between two staphylococcal species.

Bacteremia↗
PubMed2001

Survey of infections due to Staphylococcus species: frequency of occurrence and antimicrobial susceptibility of isolates collected in the United States, Canada, Latin America, Europe, and the Western Pacific region for the SENTRY Antimicrobial Surveillance Program, 1997-1999.

Between January 1997 and December 1999, bloodstream isolates from 15,439 patients infected with Staphylococcus aureus and 6350 patients infected with coagulase-negative Staphylococcus species (CoNS) were referred by SENTRY-participating hospitals in the United States, Canada, Latin America, Europe, and the Western Pacific region. S. aureus was found to be the most prevalent cause of bloodstream infection, skin and soft-tissue infection, and pneumonia in almost all geographic areas. A notable increase in methicillin (oxacillin) resistance among community-onset and hospital-acquired S. aureus strains was observed in the US centers. The prevalence of methicillin (oxacillin)-resistant S. aureus varied greatly by region, site of infection, and whether the infection was nosocomial or community onset. Rates of methicillin resistance were extremely high among S. aureus isolates from centers in Hong Kong and Japan. Uniformly high levels of methicillin resistance were observed among CoNS isolates. Given the increasing multidrug resistance among staphylococci and the possible emergence of vancomycin-resistant strains, global strategies are needed to control emergence and spread of multiply resistant staphylococci.

Anti-Bacterial Agents↗
PubMed2001

Frequency of isolation of pathogens from bloodstream, nosocomial pneumonia, skin and soft tissue, and urinary tract infections occurring in European patients.

The frequency of isolation of pathogens that cause different types of infections is an important guide for empiric therapy. As part of the SENTRY Antimicrobial Surveillance Program, the frequency of isolation of different bacterial species from bloodstream, nosocomial pneumonia, skin and soft tissue, and urinary tract infections occurring in European patients was determined. A total of 15,704 isolates were collected in 1997 and 1998 from 24 university hospitals in 14 European countries: 9,194 from bloodstream, 2,052 from nosocomial pneumonia, 2,320 from skin and soft tissue, and 2,138 from urinary tract infections. More than 95% of all bacterial infections were caused by only 15 different genera. Staphylococcus spp. and Escherichia spp, accounted for more than 50% of the infectious isolates, with the exception of those obtained from cases of nosocomial pneumonia. In the latter type of infection, isolates belonging to these two genera were responsible for 30% of the infections. An analysis at the individual species level showed that Escherichia coli caused a large proportion of bloodstream and urinary tract infections (20.8% and 49.3% of isolates, respectively). Staphylococcus aureus was the main causative species for nosocomial pneumonia and skin and soft tissue infections (21.5% and 37.4% of isolates, respectively). In addition, Pseudomonas aeruginosa played an important role in all types of infection analyzed.

Bacteremia↗
PubMed2001

Frequency of isolation and antimicrobial resistance of gram-negative and gram-positive bacteria from patients in intensive care units of 25 European university hospitals participating in the European arm of the SENTRY Antimicrobial Surveillance Program 1997-1998.

A total of 3,981 isolates from patients treated at intensive care units were collected in 25 European university hospitals during 1997 and 1998 as part of the SENTRY Antimicrobial Surveillance Program. Overall, the most important species isolated were Staphylococcus aureus, Pseudomonas aeruginosa, Escherichia coli, coagulase-negative staphylococci (CNS), Enterobacter spp., Haemophilus influenzae, Streptococcus pneumoniae, and Enterococcus faecalis. Thirty-nine percent of all Staphylococcus aureus isolates were resistant to oxacillin. All Staphylococcus aureus isolates were fully susceptible to linezolid and vancomycin. Moreover, all CNS isolates were susceptible to vancomycin and minocycline. All Enterococcus faecalis isolates were susceptible to vancomycin, and 99% of these isolates were also susceptible to ampicillin. The antimicrobial agents most effective against Pseudomonas aeruginosa isolates were amikacin, piperacillin/tazobactam, meropenem, and cefepime, with 87, 85, 84, and 83% of isolates being susceptible, respectively. Escherichia coli isolates were fully susceptible to carbapenems, and at least 99% of these isolates were susceptible to ceftriaxone, cefepime, and amikacin. The Enterobacter spp. were also highly susceptible to carbapenems, amikacin, and cefepime, with 99, 97, and 96% of isolates being susceptible, respectively. Haemophilus influenzae was susceptible to most of the antibiotics tested. Only 68% of the pneumococcal isolates were fully susceptible to penicillin, yet 100% were susceptible to a number of fluoroquinolones and vancomycin. There are still sufficient treatment options for patients infected with the most important bacterial species involved in infections in intensive care units. However, the situation for patients with Pseudomonas aeruginosa infections is critical.

Anti-Bacterial Agents↗
PubMed2001

Emergence, mechanism, and clinical implications of reduced glycopeptide susceptibility in Staphylococcus aureus.

In order to understand the mechanism(s) of the resistance/reduced susceptibility of Staphylococcus aureus to glycopeptide antibiotics, the current data on the modes of action of glycopeptides were reviewed. In addition, the different test systems for detecting vancomycin resistance and the clinical relevance of resistant Staphylococcus aureus were analyzed. Finally, strategies to prevent the nosocomial spread of these bacteria are presented, as are new therapeutic options.

Anti-Bacterial Agents↗
PubMed2001

Multi-resistance to antimicrobial agents for the ten most frequently isolated bacterial pathogens.

Cross-resistance and multi-resistance to selected antibiotics was determined for Escherichia coli, Klebsiella pneumoniae, Enterobacter cloacae, Pseudomonas aeruginosa, Staphylococcus aureus, Staphylococcus epidermidis, Enterococcus faecalis, Streptococcus pneumoniae, Haemophilus influenzae and Moraxella catarrhalis. Amikacin-resistant Enterobacteriaceae often showed cross-resistance to ss-lactam antibiotics. Only 1% of the Escherichia coli isolates showed resistance to more than four antibiotics from a set of seven. This rate was higher for other Enterobacteriaceae and there were high levels of cross-resistance for P. aeruginosa. The cross-resistance of oxacillin with other antibiotics is well known in staphylococci. Penicillin-resistant pneumococcal isolates were cross-resistant to macrolides. Cross-resistance was only a minor problem in H. influenzae and M. catarrhalis. Cross- and multi-resistance are important problems for Gram-negative and Gram-positive bacteria but not for fastidious bacteria with the exception of penicillin-resistant S. pneumoniae.

Anti-Bacterial Agents↗
PubMed2001

Molecular surveillance of macrolide, tetracycline and quinolone resistance mechanisms in 1191 clinical European Streptococcus pneumoniae isolates.

Streptococcus pneumoniae isolates (n=1191) were collected during a 1997-1999 European surveillance study. In addition to susceptibility data, a molecular epidemiological survey of their mechanisms of resistance to macrolides, tetracyclines, and quinolones was provided. Of the isolates tested, 72.6% were penicillin-susceptible, 19.9% penicillin-intermediate and 7.5% penicillin-resistant. There was an obvious relationship between resistance to penicillin and resistance to erythromycin (19% of all isolates), clindamycin (14%) and tetracycline (23%). Only one isolate was resistant to levofloxacin. Seventy-three percent of the European S. pneumoniae isolates resistant to erythromycin (n=229) carried the erm(B) gene, while the remaining 27% possessed the mef(A) gene. No mutations were detected in 23S rRNA or in ribosomal proteins L4 and L22. All tetracycline-resistant isolates (n=277) carried the tet(M) gene; none carried the tet(O) gene. Classical mutations in gyrA (Ser 81-Phe or Tyr) and parC (Ser 79-Phe and Asp 83-Asn) and efflux contributed to the decreased quinolone susceptibility. This study of recent European S. pneumoniae isolates can be used to recognize any changes in susceptibility patterns and resistance mechanisms that may occur in the future.

Anti-Bacterial Agents↗
PubMed2001

Characteristics of a new epidemic MRSA in Germany ancestral to United Kingdom EMRSA 15.

In 1996 a new epidemic MRSA emerged in three hospitals North of Berlin. This strain, Barnim epidemic MRSA, was isolated in 15 hospitals in Northern Germany in 1997 and 29 hospitals throughout Germany in 1998. Isolates of this clone are non-typeable by phages, its resistance phenotype is PEN, OXA, ERY, CLI, CIP (genotype: mecA, ermC, mutations in grlA and gyrA). The Sma I macrorestriction pattern corresponds to particular phage group II strains which is confirmed by the 16S-23S rRNA gene spacer pattern. Isolates of this clone differ by less than three Sma I macrorestriction fragments from isolates of the EMRSA15 clone from the United Kingdom, the most common epidemic MRSA isolates in the United Kingdom in recent years. Both epidemic strains produce enterotoxin C and possess the sec determinant for this toxin, the configuration of the mec regulon is mecI-, mecRB+, mecRC+. Both share the same Alu I pattern of PCR amplimers of the 3' end region of the coagulase gene. EMRSA 15 and Barnim EMRSA share a common multilocus sequence type indicating a recent, shared evolutionary origin.

Bacterial Typing Techniques↗
PubMed2001

Milolides, new briarane diterpenoids from the western Pacific octocoral Briareum stechei.

Eleven new briarane-type diterpene lactones, designated milolides (1--8, 10--12), together with four known diterpene lactones (9, 13--15), were isolated from the Micronesian octocoral Briareum stechei collected at Yap, Federated States of Micronesia. One aspect of the stereochemistry of one of the known compounds, solenolide C (9), is revised. Structures of the new compounds were determined from spectral data.

Animals↗
PubMed2001

Four new coumarin derivatives from Artemisia keiskeana.

Four new coumarin monoterpene ethers, artekeiskeanols A-D (1-4), and three known coumarins, isofraxidin, fraxidin, and daphnoretin, were isolated from the whole plants of Artemisia keiskeana. All structures were determined from spectral data, and that of artekeiskeanol A (1) was confirmed by synthesis.

Alkaloids↗