The era of antimicrobial resistance-implications for the clinical laboratory

[Single dose of antibiotic prophylaxis in elective cesarean sections]

INTRODUCTION

The aim of our study was to determine whether a single-dose preoperative administration of antibiotics was sufficient to prevent intra and postoperative infections in the parturients without a high risk of developing an infection, in whom the delivery was completed by cesarean section, as well as to answer whether the administered dose of antibiotics satisfied the requirements of therapeutic concentrations necessary to protect against infection in the period during the surgical procedure and during the first 6 postoperative hours.

MATERIAL AND METHODS

All investigated pregnant women were planned to have elective cesarean section as a mode of delivery. They were distributed in groups depending on the type (cephalexin, gentamycin and cephazolin) of antibiotic prophylaxis administered as a single dose. In all patients the clinical postoperative course was followed for possible infection. The concentrations of antibiotics were estimated immediately and 6 h following the operation. The estimation of antibiotic concentrations was done by the method of liquid chromatography (for antibiotics belonging to the group of cephalosporins), i.e. RIA method for antibiotics from the group of aminoglycosides.

RESULTS AND CONCLUSION

The total number of infections in investigated groups was 5.18%. The measured mean concentrations of administered antibiotics following the operation and 6 h later were above MIC. This is a proof that the obtained antibiotic prophylaxis by a single dose administration of anbtibiotic is sufficient to prevent the invasion of pathogenic microorganisms from the skin.

INFECTIOUS DISEASES

The emergence of new pathogens, or the concern about bioterrorism, has brought an added urgency to the development of more efficient and rapid methods to detect pathogens and predict their potential virulence. Till date, DNA testing in microbiology has been directed predominantly to the detection of organisms that are difficult to culture in vitro, or for various reasons the growth is unlikely. DNA analysis can be used successfully in infections in which there is a mix of pathogens. Apart from the straightforward diagnostic applications, DNA microbiological testing has been used to detect antimicrobial resistance or toxigenic forms of E. coli. More recently, the availability of DNA technology to quantitate HCV and HIV has been useful in planning and monitoring treatment. The pathogenesis of many infections, particularly viral ones, can also be realized from experimental strategies based on light and electron microscopy, cell culture and immunoassay. The advantages that are provided by DNA techniques include the ability to detect latent (non-replicating) viruses and to localize their genomes to nuclear or cytoplasmic regions within cells. Nucleic acid probe techniques (NAT) can also be manipulated to enable a broad spectrum of serotypes to be detectable. This is particularly valuable in those emerging infections where the underlying serotypes are unknown.

Quinupristin-dalfopristin resistance in Streptococcus pneumoniae: novel L22 ribosomal protein mutation in two clinical isolates from the SENTRY antimicrobial surveillance program

Resistance to quinupristin-dalfopristin (Q/D) among gram-positive cocci has been very uncommon. Two clinical isolates among 8,837 (0.02%) Streptococcus pneumoniae isolates were discovered in 2001 to 2002 with Q/D MICs of 4 micro g/ml. Each had a 5-amino-acid tandem duplication (RTAHI) in the L22 ribosomal protein gene (rplV) preventing synergistic ribosomal binding of the streptogramin combination. Similar gene duplication has been reported in Q/D-resistant Staphylococcus aureus.

Resistance issues and community-acquired respiratory infections

Antimicrobial resistance, associated with both excessive and inappropriate use of antimicrobial agents, is a global problem. It is a particular problem in the management of community-acquired respiratory infections, which most often result in the use of antimicrobial therapy. Infections caused by resistant and multiresistant pathogens may also result in high hospitalization rates, long lengths of stay, severe illness, and high mortality, all of which have a great impact on health care costs. The Tracking Resistance in the United States Today (TRUST) Program, the largest longitudinal continuous-surveillance program of its kind, has been conducted every year since 1996 and tracks consecutive respiratory seasons on a year-to-year basis to monitor resistance patterns of respiratory pathogens. This article discusses some of the findings of the TRUST Program, particularly trends in Streptococcus pneumoniae resistance.