Unknown Bacterial Environmental Isolate Report

The identification of an unknown bacterial environmental isolate through a series of morphological, physiological and differential exercises. The purpose of the environmental isolate report is to learn what is necessary in order to take an unknown environmental isolate (EI) and identify it. This was achieved through a series of exercises that provided information on the morphological, physiological and biochemical traits of the EI which were then compiled and interpreted in order to make a presumptive identification of the EI. The EI sample was taken from a door handle to the George Lynn Cross Hall, which is touched by hundreds of students entering the building every day. The most important exercises performed include gram staining, which
One specifically important stain preformed was the Ex 3-7 Gram Stain, which showed the EI to be a gram-positive cocci that appeared in small clusters, in addition the endospore stain revealed this to be a non-endospore forming bacterial species. These results are important because they drastically narrow the possible bacterial species the EI could be. Many differential tests were performed on the EI, specifically differential tests that provide information on cellular respiration (Table 4). These differential exercises test the different biochemical processes that the EI can preform. Ex 5-2 oxidation-fermentation test showed the EI to be capable of oxidation and slow fermentation or fermentation only. Ex 5-21 Triple Sugar Iron Agar test showed the EI can ferment glucose and sucrose and/or lactose but is not a sulfur reducer. Ex 5-4 showed the EI is able to preform 2,3 butanediol fermentation and produce acetoin. Many differential tests that tested the enzymatic properties and activity of the EI (Table 5). The results show the EI to be a catalase positive organism. The EI is also coagulase negative. The Beta-Lactamase test showed the EI is
This result was imperative for the determination of the specific species since it is an easy way to begin the task of narrowing down the possible species.Ex 5-5 Catalase Test showed catalase positive results. This is a key characteristic of the Staphylococcus species (Bergey). Ex 2-2 Colony Morphology showed circular white opaque colonies with smooth, entire margins when grown on TSA. This is key in helping to determine whether the EI was a Staphylococcus spp or a Mircroccus spp since Mircroccus spp. commonly show yellow color colonies when grown on TSA and Staphylococcus spp are commonly opaque white colonies when grown on TSA (Bergey). Additionally, Ex 3-10 Endospore Stain showed the EI to be non-endospore forming, which corresponds to the characteristics listed in Bergey s Manual of Determinative Bacteriology under the species Staphylococcus (Bergey 464). Ex 5-28 Motility Test showed the EI to be non-motile, which is also a key characteristic of Staphylococcus species