A longitudinal study of antimicrobial resistant faecal bacteria in sediments collected from a hospital wastewater system.

Objective: The objective with this study was to determine and follow antimicrobial resistance in faecal bacteria over time in hospital wastewater pipe sediment. A further aim was to determine bacterial growth rates of sensitive, intermediate and resistant intestinal enterococci in different ciprofloxacin concentrations as a measure of bacterial fitness.

Methods: A system enabling the collection of settled particles over time was installed at Kalmar County Hospital.

A comparative study of three methods to evaluate an intervention to improve empirical antibiotic therapy for acute bacterial infections in hospitalized patients.

Background: In order to limit the use of broad-spectrum antibiotics, standardized empirical therapy against acute bacterial infections has been advocated.

Methods: Guidelines for acute bacterial infections recommending increased usage of benzylpenicillin and restricted use of fluoroquinolones and cephalosporins have been implemented in Kalmar County, Sweden. We evaluated this strategy by recording therapy in patients with bacteraemia, antibiotic requisition, and point prevalence surveys prior to this intervention and at 6 and 12 months after.

Quantification of genes encoding resistance to aminoglycosides, beta-lactams and tetracyclines in wastewater environments by real-time PCR.

In this study real-time PCR assays, based on the LUX-technique, were developed for quantification of genes mediating resistance to aminoglycosides [aac(6 ')-Ie + aph(2 ' ')], beta-lactams (mecA), and tetracyclines (tetA and tetB), for use in wastewater environments. The developed assays were applied on DNA extracted from three wastewater-associated environments: soil from an overland flow area treating landfill leachates, biofilm from a municipal wastewater treatment plant, and sludge from a hospital wastewater pipeline. The highest concentration of all genes was observed in the hospital pipeline and the lowest in the overland flow system.

Determination of antibiotic substances in hospital sewage water using solid phase extraction and liquid chromatography/mass spectrometry and group analogue internal standards.

A method for determination of antibiotics in hospital sewage water has been developed and validated. Analogue internal standards for fluoroquinolones, sulfonamides, trimethoprim, beta-lactams (penicillins and cephalosporins), nitroimidazoles and tetracyclines were successfully used for calibration and shown to generally improve precision compared to external calibration. Matrix components caused ion suppression/enhancement effects during the MS detection for all analytes studied.

Fluoroquinolone antibiotics in a hospital sewage line; occurrence, distribution and impact on bacterial resistance.

In hospital sewage lines, human faecal bacteria are exposed to antibiotics, posing a risk for selection of antibiotic resistant microorganisms. We constructed a system for continuous sampling in a hospital sewage line that allowed us to study longitudinal establishment of bacteria, concentrations of antibiotics, and selection of bacterial resistance in waste water, sediment and biofilm. The focus in this study was on fluoroquinolones, a widely used group of antibiotics with increasing resistance problems.