Esblb Strain Lab Report

K. pneumoniae is a gram negative, facultative anaerobic, gamma-proteobacteria that can cause pneumonia, urinary tract infections, cholecystitis, and septicemia. (Strand & Shulman 1988)
As shown in Table 1., many organisms have developed resistances to commonly used antibiotics. The difference between the standard strain of Klebsiella pneumoniae and the extended spectrum betalactemase (ESBL) strain, for example, is striking. 12 antibiotics had greater than or equal to 95 percent effectiveness against the common K. pneumoniae strain, while only 2 antibiotics were as effective against the ESLB strain. P. aeruginosa and K. pneumoniae are only two of the many clinically relevant gram negative species that have recently become resistant to various
In this experiment we will inoculate individual vials of nutrient broth with various organisms that are known to be resistant to multiple antibiotics. We will also inoculate various organisms that are as close to the wild type as is feasible. The vials will be allowed to incubate at 37 degrees Celsius for 24 hours. The number of bacteria in a given cultured sample is too great to be counted directly. The samples will be serially diluted by a factor of 10 in sterile saline, to be repeated 7 times. A 10 microliter aliquot from each dilution will be placed on a 5% blood agar plate or a MacConkey plate, depending on the type of organisms plated. These plates are selected because of the ease of differentiation between organisms. The original vial and all diluted aliquots will then be refrigerated to restrict growth until the plates can be processed and evaluated. The plates will be streaked in the standard format for colony count. The plates will be incubated at 37 degrees Celsius for 24 hours. The plates will then be examined for purity of culture and for colony count. The number of colonies will be counted for each dilution. The plates that have a colony count between 300 and 30 will be used to estimate the number of viable cells in that dilution. This range is chosen because small dilution errors could have a
Required materials include stock cultures of organisms to be tested. Methicillin resistant S. aureus, Streptococcus pyogenes, Streptococcus pneumoniae, Proteus mirabilis, and ESBL K. pneumoniae would be excellent choices because of their characteristic morphologies. (Gladwin & Trattler 2011) Multiple Cefepime and Ceftriaxone antibiotic discs will be needed to preform sensitivities. 5% sheep blood agar plates and MacConkey agar plates in sufficient quantities to subculture each test sample regularly. Nutrient broth tubes, or alternatively a nutrient broth bottle with sterile test tubes, will allow for mixing samples and incubation. Parafilm wax will be used seal tubes and plates. Sterile saline will be needed to dilute the nutrient broth. Prepacked sterile inoculating loops or a metal loop with portable incinerator will be used to streak out the plates. 37 degree Celsius Incubator will be needed. A Micropipeter (10 microliter) with tips are required to prepare aliquots and