Note on Clinical Microbiology And its Applications

Abouit the Study

By providing clinicians with information on the source of illness and antimicrobial susceptibility, the clinical microbiology laboratory plays a vital role in patient treatment. It's critical to diagnose pathogens quickly so that antibiotics can be administered effectively and treatment outcomes can be improved. Phenotypic identification and gene sequencing are used in traditional microorganism diagnosis, which is time-consuming and tiresome. MALDI–TOF/MS, on the other hand, is a low-cost, simple, quick, and repeatable approach for detecting infections. MALDI–TOF/MS permits highly selective identification of bacteria, yeasts, and filamentous fungi even after 10 minutes of culture by using distinctive peptide and protein profiles derived from intact cells. The approach's reliability and accuracy have been proved using a database to identify microorganisms, and systems have been developed. Clinical microbiology is concerned with isolating and characterising infectious organisms in order to manage and treat them in patients. Bacteria, fungi, viruses, and parasites all have a role in infection. A sample from a patient at a body place where the identification of a pathogen or its associated biomarkers is likely to suggest disease is required to diagnose an infection. The specimen must be transferred to the laboratory in such a way that it can be tested. The sample must next be examined for the putative disease-causing organism in a sensitive and specific manner. Finally, these findings must be communicated to a clinician in a way that allows him or her to effectively evaluate and act on them.

Clinical Microbiology is the first branch of personalized medicine, according to many experts. The indications and symptoms of a urinary tract infection, for example, include increased urination urgency, frequently, and pain. A urine sample is taken and quantified cultured. The kind and number of bacteria identified in the urine are reported by the clinical microbiology lab within 24 hours. The susceptibility of that patient's bacterial isolate to a panel of drugs authorized to treat urinary tract infections is reported by the laboratory 1–2 days later. Following that, the patient's clinician might select an antibiotic that is expected to be successful against the infection. Robert Koch, a pioneering microbiologist, set the clinical microbiology paradigm that is still used today.

In order to prove that Bacillus anthracis caused the disease anthrax, he developed Koch's postulates, which are:

1. The microorganism must be observed in all cases of the disease,

2. The microorganism must be isolated and grown in pure culture,

3. Microorganisms from the pure culture must reproduce the disease when inoculated into a susceptible animal, and

4. The microorganism must be observed in and recovered from the experimentally dissected animals. By fulfilling these criteria, several pathogens have been linked to disease.

Antimicrobial treatment management

Primary (direct) and secondary (indirect) antimicrobial sensitivity tests of this sort are available (indirect). The clinical material, such as pus, is inoculated directly onto the test zone of the plate in a primary test. The benefit of this method is that after 24–48 hours of incubation, the total sensitivity data for the organisms found in pus will be accessible. When treating debilitated patients with acute infections, such as dent alveolar abscesses, this is especially beneficial. Secondary sensitivity tests are carried out on a pure culture of the isolates found in the specimen; however the findings are not accessible for at least 2–4 days after collection. Minimum Inhibitory Concentration (MIC) and Minimum Bactericidal Concentration (MBC) tests were performed (MBC).

These assays determine the potency of an antibiotic in a quantitative manner. A set of tubes can be used to integrate a variety of two-fold dilutions of an antibacterial agent into a suitable broth (tube dilution technique). The broth is infected for 18 hours with a standardized suspension of the test organism. The MIC is defined as the lowest concentration of a medicine that prevents the test organism from growing in the tube. Following that, a standard inoculum from each of the tubes that did not grow can be subcultured on blood agar to establish the Minimal Medication Concentration required killing the organism (MBC). The minimal concentration of medicine required to kill 99.9% of the test microorganisms in the initial inoculum is known as the MBC. The 'breakpoint' or 'critical' concentration test, a semi-quantitative form of the normal MIC test, is a modification of the MIC test. A restricted number of medication concentrations are utilized rather than a full series of doubling dilutions in this procedure, which can be carried out by introducing antimicrobial agents into either broth or agar. These tests are not regularly conducted, but they can be helpful in patients with significant infections who need to receive the best antibiotic treatment possible. Streptococci isolated from blood cultures from patients with infective endocarditis and some bacterial strains that cause septicaemia in immunocompromised patients are examples.