Lab 16 Antibiotic Susceptibility Testing

Gold standard procedures should be implemented with the aim of providing timely and accurate results. (Schentag) The culture result should be accompanied by its clinical significance, selective reporting of susceptibility testing results in accordance with hospital antimicrobial therapy guidelines and suggested management. (Schentag) This encourages appropriate prescribing and minimises unnecessary use of antimicrobials. The clinical microbiology team should also provide reports to AMS regarding resistant organisms.

As predicted the E. coli colony transformed with either the PUC18 or the lux plasmid developed an ampicillin resistance. Which made it easier for them to not only survive but also replicate in both the LB agar plates and the LB ampicillin rich agar plate. However the E. coli colony not treated with the plasmids could not survive and colonize in the LB ampicillin rich agar plates. The plate that had no ampicillin in its environment and no plasmid treated E. coli served as a positive control for this experiment because it demonstrated how the E. coli would colonize and grow in a normal setting. The cells in the positive control plate grew into lawn colonies because they were not placed into a selective environment or transformed, so they had no need to acquire ampicillin resistance. Two plates in the experiment contained E. coli cells that were transformed with either the PUC18 or the lux plasmid but were placed in an ampicillin free environment. These two colonies grew

The antibiotics will have different zones of inhibition on different bacteria. Also, a range of concentrations of the nutrients in the bacteria will change the bacterial growth.

The aim of this investigation was to find out which antiseptics were most effective at preventing the growth of bacteria.

Dr. Gumma mentioned that in prescribing antibiotic, it is very important to determine the patient’s allergy to

E.coli outbreaks have steadily grown over the last few decades. An expansion in big farming has led to E. coli not only being found in meat, but vegetation as well, due to waste runoff. This has increased our need for adequate antibiotics that can fight bacteria, like E. coli. The best way to pinpoint which antibiotics work is by measuring their ability to create antimicrobial agents or zones of inhibition. When a paper disc that has been saturated in an antibiotic is inserted in a solution of E.coli and medium, the zone of inhibition will be noted as the clear ring that forms around the disk. The antibiotics efficacy is then determined by measuring each disk zone of inhibition, and comparing these measurements to the zone measurements of an untreated specimen. If an antibiotic is to be deemed sufficient for treating E. coli it should show a zone of inhibition that is at least double the size of the untreated specimen.

Yes: Discussion and summary of evidence about studies on bacterial agents, antimicrobial resistance and considerations in selection of an antibiotic regimen.

1 and 3). This antibiotic is effective against both gram positive and negative bacteria, so it would be effective against Staphylococcus epidermidis. This antibiotic is able to kill bacteria by interfering with the cell wall synthesis, weakening it, and causing its death. However, just like with Penicillin, some bacteria have become resistant to this antibiotic (6). The hypothesis stated that Staphylococcus epidermidis would be susceptible to Ampicillin because although some bacteria have become resistant this one has not (7). According to the class data, two of the tests resulted in in susceptibility, one resulted in an intermediate effect, and the rest were resistant (see Figs. 2 and 5). It seems that Staphylococcus epidermidis is in the process of becoming resistant to Ampicillin because of the varied data. However, the group data did not support the hypothesis that the bacteria would still be

One person each in a team of four heavily inoculated two Mueller-Hinton agar plates with one of the cultures listed by aseptic transfer from a broth culture using a sterile cotton swab. Each plate was marked off into four segments, a total of eight sectors. One McFarland standard disk containing one of the eight antibiotics tested was placed, using

Physicians perform gram stains before prescribing an antibiotic to know if the cell wall type and the antibiotic sensitivity link.

It also helps with the prevention of PCP in HIV-positive patients, but should be used cautiously due to the incidence of adverse reactions. This drug is also active against many strains of gram-positive pathogens including: Streptococcus pneumoniae, Staphylococcus aureus, Group A beta-hemolytic streptococci, Nocardia, Enterococcus. It also has activity against many gram-negative pathogens, such as: Acinetobacter, Enterobacter, Klebsiella pneumoniae, Escherichia coli, Proteus mirabilis, Shigella, Xanthomonas maltophilia, and Haemophilus influenzae, including ampicillin-resistant

Antibiotic stewardship program for this study is the independent variable, which is operationally defined as a program that provides education to clinician on the diagnosis, treatment plan and strategy for the prevention of CDI. In this program, a checklist with high, medium and low risk antibiotics is provided to prescribers with guidelines and microbiological diagnostic to help prevent the inappropriate diagnosis of high risk antibiotics. In this list, Tetracycline, Linezolid, Fosfomycin, Vancomycin, Daptomycin, Metronidazole, and Trimethoprim/sulfamethoxazole were identified as the low

The activity of antimicrobial combinations can be assessed in vitro using Etest methods. The traditional approaches used to assess antimicrobial combinations are the checkerboard and time-kill methods These methods are costly in time and materials and are not used in routine clinical practice. The Etest method is simple to use, time efficient and inexpensive. The Etest is an agar diffusion method for the quantitative determination of susceptibility to antimicrobial agents [9].

The objective of this lab was to measure the zones of inhibition of the discs that were soaked in different hand-cleansing agents/antibiotics and put in agar plates that were swabbed with Escherichia coli culture. In order to do this, we used the Kirby-Bauer method. The Kirby-Bauer method is a test of detect the antibiotic sensitivity to bacteria. The method is used by using antibacterial discs to see which bacteria are affected by those antibiotics. My hypothesis, stated before the experiment, was that penicillin will have the smallest zone of inhibition because it is an antibiotic, and it will work the best.

This experiment was done to better understand what types of antibiotics do well against the strain of S. aureus, MRSA. The experiment consisted of various types of antibiotics to see if there would be any