Microbiology

We as a competent partner will assist you with our broad range of microbiological analyses. The microbiological preanalysis is because of its wide range of possible materials and flatware special. Proper removal of the sample and faster transportation is essential for the infection diagnostics. On this page you will find important advice and leaflets on how to collect samples.

Detection of Pathogens

Please target the site of infection when collecting samples for the detection of pathogens. These samples should not be contaminated and if possible, collected before a course of antibiotics is started. Repeated withdrawals increase the diagnostic sensitivity. Pus, secretions, and punctate amounts of more that 2 mL as well as tissue samples are preferred because they can be enriched and are better suited for diagnostic purposes than swabs.

An overview of the storage of common investigative materials until transportation can be found in the table Storage of Specimens.

Required Information on the Order Form

• Type of patient sample
• Sampling time (date, time)
• Clinical (suspected) diagnosis, brief description of samples
• Prior treatment: information regarding any course of antibiotics
• Underlying disease (ex. cancer, Immunosuppresion)
• Ambience, travel history
• desired tests with questions

General Orders: Pathogens + Resistance (E+R)

If reasonable or possible, the sample and culture will be examined microscopically for pathogenic bacteria and any pathogens will be differentiated and tested for antibiotic resistance. Age, gender, and any questions are taken into consideration.

Orders to be made include, but are not limited to molecular and culture studies such as actinomycetes, group A streptococci (except in the throat), chlamydia, cholera, diphtheria, gonorrhea, Helicobacter pylori, Legionella, Mycoplasma, pertussis, fungi, Pneumocystis, protozoa, tuberculosis and mycobacteria, all viral pathogens, worms, and worm eggs.

If you wish any special tests besides the conventional microbiological diagnostics to be undertaken, you must request it. These include PCR (Polymerase Chain Reaction to investigate for pathogen specific DNA), or antigene detection. All materials for microbiological examinations must be sent in special individual transport cases (ex. cervix swab for chlamydia/gonorrhea, and a second swab for culture). Clinical history or clinical peculiarities should always be noted on the accompanying order form (ex. travel abroad).

All materials must be regarded and treated as potentially infectious. Therefore, all materials must be encased in sterile, shatter and break proof vials (DIN 55515 Part 1).

Antibiograms

Susceptibility testing is usually carried out as a quantitative microdilution (break-point) or with an agar diffusion test.

The accessment of results includes the MHK, pharmacokinetics, and pharmacodynamics of the substances. Testing takes place in accordance with the European wide standardized requirements of EUCAST.

Hence the classification results in three sensitivity ranges:

• sensitive: expected therapeutic success at appropriate indication.
• Intermediary: therapeutic success depending on methodology not guaranteed. Consideration of clinical conditions, the possible drug dosages and evaluation of the complete resistance profile for drug selection necessary.
• resistant: therapeutic success not expected.

The substances tested are a selection of frequently used antibiotics in hospitals and practices. Antibiotics which are not clinically effective in certain pathogens, are not tested (ex. cephalosporins in enterococci).