Question

Antibiotic susceptibility test with all explanation

Answer 1

Ideal antibiotic therapy is based on determination of the aetiological agent and its relevant antibiotic sensitivity. Empiric treatment is often started before laboratory microbiological reports are available when treatment should not be delayed due to the seriousness of the disease. The effectiveness of individual antibiotics varies with the location of the infection, the ability of the antibiotic to reach the site of infection, and the ability of the bacteria to resist or inactivate the antibiotic. Some antibiotics actually kill the bacteria (bactericidal), whereas others merely prevent the bacteria from multiplying (bacteriostatic) so that the host's immune system can overcome them. Müeller-Hinton agar is most frequently used in this antibiotic susceptibility test. [4]



Antibiogram, palatine tonsil smear of a dog with tonsillitis, Mueller-Hinton agar. Only Amoxicilline-Clavulanic acid(AMC) and Chloramphenicol (C) show an inhibition of bacterial growth.

An antibiogram is the result of an antibiotic sensitivity test. It is by definition an in vitrosensitivity, but the correlation of in vitro to in vivo sensitivity is often high enough for the test to be clinically useful.

In clinical practice, antibiotics are most frequently prescribed on the basis of general guidelines and knowledge about sensitivity: e.g. uncomplicated urinary tract infectionscan be treated with a first generation quinolone, etc. This is because Escherichia coli is the most likely causative pathogen, and it is known to be sensitive to quinolonetreatment.

However, many bacteria are known to be resistant to several classes of antibiotics, and treatment is not so straightforward. This is especially the case in vulnerable patients, such as patients in the intensive care unit. When these patients develop a hospital-acquired pneumonia, more hardy bacteria like Pseudomonas aeruginosa are potentially involved. Treatment is then generally started on the basis of surveillance data about the local pathogens probably involved. This first treatment, based on statistical information about former patients, and aimed at a large group of potentially involved microbes, is called empirical treatment.

Before starting this treatment, the physician will collect a sample from a suspected contaminated compartment: a blood sample when bacteria possibly have invaded the bloodstream, a sputum sample in the case of a ventilator associated pneumonia, and a urine sample in the case of a urinary tract infection. These samples are transferred to the microbiology lab, which looks at the sample under the microscope, and tries to culture the bacteria. This can help in the diagnosis.

Answer 2

no antibiotic susceptibility test with all because more dose loss of our body