Discovery and description of Aeromonas species: From the discovery of genus Aeromonas in 1943 till mid - 1970s, aeromonads are initially divided into two major groups; based upon growth characteristics and other biochemical features (Janda, and Duffey, 1988). This mesophilic group, typified by A. hydrophila, consisted of motile isolates that grew well at 35 °C to 37 °C and are associated with a variety of human infections (Ref ). In the second group, referred to as psychrophilic strains, caused diseases in fish that are nonmotile, and had optimal growth temperatures of 22 °C to 25°C. This group represent with isolates that currently reside within the species A. salmonicida (Ref ). Ten year following mid-1970s, several other groups were interested in the work that include Institute Pasteur, Paris, Centers for Disease Control and Prevention, Atlanta, USA, and Walter Reed Institute of Research, Washington USA. These institutes spearheaded an effort to redefine this …show more content…
Aeromonads are literally responsible for a “cornucopia” of intestinal and extraintestinal diseases and syndromes, ranging from relatively mild illnesses such as acute gastroenteritis to life-threatening conditions, including septicemia, necrotizing fasciitis, and myonecrosis (142). The panorama of maladies linked to this genus goes far beyond those listed above and includes intra-abdominal problems, ocular disease, infections of bones and joints, and even less frequently observed conditions involving the respiratory and urogenital tracts. Based upon frequency, Aeromonas clinical infections fall into four broad categories, namely, (i) gastrointestinal tract syndromes, (ii) wound and soft tissue infections, (iii) bloodborne dyscrasias, and (iv) a miscellaneous “catch-all” category which includes a myriad of less frequently encountered ailments and infectious
Methods Unknown microbial #398 went through several of tests in order to identify its characteristics when isolated from a urine sample of Doris, a 64- year old patient with a kidney infection. To identify unknown #398, must prepare a working and a reserve stock by the inoculation from a broth culture and by quadrant streaking method on a PEM and EMP plates. The following test procedures were incubated at 37°C for 48 hours for observation and identification for unknown #398. The identification of unknown #398 followed test procedures from Brown1.
After 5 days the plates were removed from the cold room and the gram-negative test for Colony A on the EMB agar showed pink fisheye colonies which lead to the conclusion that the gram-negative organism within Unknown #21 was Enterobacter aerogenes. Had the pigmentation been metallic green, the organism would have been identified as Escherichia coli, and had there been no pigmentation at all a Triple Sugar Iron agar (TSI) test among other tests would have been
The purpose of this lab report is to employ a myriad of skills, tools and, methods learned throughout this semester to perform the appropriate tests for the identification of the assigned unknown bacteria. Add more background information here!!! The most important tools and techniques used during this identification include aseptic technique, microscopic examination and, the use of selective and differential media. Aseptic technique is an important tool for microbiologists. It is imperative that aseptic technique is maintained throughout the length of any test to avoid any cross-contamination that may lead to inaccurate results.
The Unknown Identification Lab was an experiment that provided the opportunity to apply all the tests that were learned in the semester of lab, to identify the two bacterias that remain unknown. Gram- staining and two other tests will be used to identify the unknowns. This experiment is crucial to the understanding of each test, and can benefit in the ability to identify the characteristics of specific bacteria. Having a clearer understanding of the bacteria can further the research of bacteria for medicine, such as antibiotics. The understanding can also help the development of research in the environment.
In the laboratory, identification of an unknown bacterium is often necessary. In the lab, a random sample consisting of three different bacteria was selected. The sample contained one gram-positive, one gram-negative paracolon, and one gram-negative coliform. The purpose of the experiment is to identify each of the three species that the mixture contained. After receiving an unknown mixture, the sample was streaked for isolation onto TSA, blood agar, and MacConkey plates.
Being able to identify unknown microbes from systematic testing is what makes the field of microbiology so important, especially in infectious disease control. Using the testing procedure laid out by the microbiology field we are able to identify unknown bacteria present in our everyday lives, and along the way learn a lot about their characteristics that separate them from other types of bacteria. Being able to do this is vital in order for us to understand why microbes are present in certain places, how they are able to grow and what restricts their growth, that way they can be combatted if necessary. These techniques for determining unknowns are also important for isolating and testing infectious disease microbes in order to prevent spreading. Another important aspect of being able to identify unknown microbes is the
3.1 The isolation of Aeromonas from several pond waters, healthy fish, and infected fish The isolate of A. hydrophila grown for 24 hours at 37C on Rimler-Shoots+novobiocin medium should show bright yellow color with white edge. Figure 1 shows the control of isolate A. hydrophila ATCC 7699 grown on RS+novobiocin medium. Isolate selection on RS medium resulted in 95 isolates, presumed to be A. hydrophila, which would run the phenospecies test (morphology and biochemistry), based on the protocol of SNI 7303 (2009), plus one control isolate the A. hydrophila ATCC 7699 obtained from Microbiologic Co. Figure 1.
So the results were sulfur: positive, indole: Negative, and for medium: medium motility. And the results indicated that could be Klebsiella pneumoniae but also it could be Enterobacter aerogenes. To confirm the deduction of hat my bacterium could be Klebsiella pneumoniae I decided to do my fourth test. And the Urea Hydrolysis and if the results turn negative the bacterium will be Enterobacter aerogenes, or if it turns positive the bacteria will be Klebsiella pneumoniae.
Starch amylase testing was equally unsubstantial since the only amylase producing bacteria was ruled out after Gram staining. Unknown #10’s negative citrate test result was also unhelpful because E. coli is citrate negative and P. vulgaris is a variable citrate producer that can also be citrate negative. H2S production in the Kligler’s Iron Agar test ultimately proved that Unknown #10 was Proteus vulgaris. P. vulgaris is the only assigned bacteria that produces H2S, so when a black precipitate obscured the yellow butt of the Kligler’s Iron Agar slant, E. coli was ruled out. Not only did the H2S product confirmed that Unknown #10 was P. vulgaris, it confirmed P. vulgaris’ motility.
This bacteria lives in the upper respiratory tract without any problems, but when introduced to the
According to the series of test that my group ran for our unknown specimen, we had a match with the bacteria known as Alcaligenes Faecalis. This bacterium belongs to one of the major group of gram-negative bacteria (Phylum Proteobacteria). Alcaligenes Faecalis (Genus, species) is a rod shaped (bacillus), 0.5-1.2 x 1.0-3.0 µm, round with scalloped margin (colony configuration growth), motile (with one to nine peritrichous flagella), gram-negative, non-fermentative bacteria, obligate aerobic, having oxygen as the principal terminal electron acceptor in the electron transport chain (ETC). We consider we have a match with the species Alcaligenes Faecalis because of the following reasons: Fermentation tests performed (Durham sugars) were negative, which indicate that our bacteria use a different metabolic means for growth (non-fermentative gram-negative bacteria).
Pseudomonas aeruginosa causes a wide variety of septic infections in man and other vertebrates (Hare and Wilits, 1962). Among species much less commonly encountered in wound infections are Pasteurella multicida in animal bites, Corynebacterium diphtheria and Bacillus anthracis in malignant pustules of skin. In chronic infection that are slow to heal and in pus showing no
Aseptic technique was initiated at the beginning of this experiment by cleaning the work surface with disinfected wipes. Personal protectives equipment was also worn. The material utilized in this experiment was: S. epidermidis culture broth, sterile cotton swab, streak plate, forceps in 70% alcohol, a lit tea light, and the three antibiotic disks (novobiocin, gentamicin, penicillin). The first step, I divided a plate into three quadrants and labelled them with the different antibiotic names. Using the lit tea light, like a bursen burner, I flamed the mouth of the S. epidermidis culture.
The Legionellaceae are thin, aerobic, pleomorphic, flagellated, Gram-negative opportunistic intracellular bacteria. They are non-capsulated rod-like bacterium of approximately 2 μm in length and 0.3-0.9 μm in width. Legionella pneumophila has suggested fastidious nutrient requirements, including ferric iron and L-cysteine. The family Legionellaceae consists of a single genus, Legionella. This genus includes the species Legionella pneumophila, the most frequent cause of human legionellosis and it known as Legionnaires’ disease.
The media used in this experiment was Trypticase nitrate broth. The reagents used (A and B) were sulfanilic acid and alpha-naphthylamine (respectively). Using aseptic technique, the bacterium (16A and 16B) were inoculated into labeled broth test tubes. The tubes were incubated for 48 hours at 37 degrees Celsius. When the incubation was complete 5 drops of reagent A and 5 drops of reagent B were added to each of the broths.