Method for screening and identifying antibiotic resistant bacteria

Abstract

The invention belongs to the technical field of bioengineering, and particularly relates to a method for screening and identifying antibiotic-resistant bacteria. According to the method, the soil suspensions with different concentration gradients are coated, and the optimal dilution gradient for effectively selecting single colonies is determined according to the condition of the colonies growing on a flat plate, so that subsequent large-batch screening and identification of antibiotic-resistant bacteria are facilitated; according to the method, the growth speed of the resistant bacteria is controlled by controlling the concentration of erythromycin, streptomycin and polymyxin B sulfate in the resistant culture medium, so that the purpose of accurately screening the drug-resistant bacteria is achieved; the sterilization gun head is used for replacing a traditional inoculating loop to select single colonies, the bacterium selecting step can be completed by repeated blowing and beating, and the problems that a large amount of time is consumed when the inoculating loop is burnt and cooled, the cooling degree is difficult to control, and bacteria are scalded to death are avoided.

Description

technical field [0001] The invention belongs to the technical field of bioengineering, in particular to a method for screening and identifying antibiotic-resistant bacteria. Background technique [0002] Antibiotics are now widely used in healthcare and animal husbandry to treat or prevent bacterial infections. However, the excessive use of antibiotics has led to an increase in the residual antibiotics in water, soil, and air. The antibiotic selection pressure generated by the misuse of antibiotics causes the bacteria to produce antibiotic resistance mutations. Excessive use of antibiotics will form selective pressure on environmental bacteria. Long-term heavy use of antibiotics will increase the number of drug-resistant bacteria and enhance drug resistance. The abuse of antibiotics is an important factor for bacteria to produce antibiotic resistance genes. [0003] Antibiotics can be introduced into soil through irrigation with recycled water, sludge and manure used for c...

AI Technical Summary

Problems solved by technology

This experimental method is suitable for a small number of soil samples. If a large number of cultivable antibiotic-resistant bacteria in soil samples need to be screened, the workload is huge, it takes a long time, and the effect is not good.

In addition, it is difficult to control the concentration of antibiotics by using antibiotic resistance plates to screen resistant bacteria. It is also difficult to determine the appropriate concentration of antibiotics based on the minimum inhibitory concentration provided by CLSI or EUCAST. All resistant bacteria in the sample can be screened out as much as possible.

If the concentration of the resistant plate is too low, the bacteria will grow faster and the species will be complicated, which can only exclude the bacteria that are sensitive to the antibiotic, and it is easy to carry miscellaneous bacteria; if the concentration of the resistant plate is too high, the bacteria will grow slowly and cannot be screened out. Moderately sensitive (I) bacteria greatly reduce the screening effect

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