MATERIALS AND METHODS
Detection of microorganisms in the blood samples
The presence of microorganisms in blood samples from hospitalized patients was detected by use of the BacT/ALERT Microbial Detection System (bioMérieux, Marcyl’Etoile, France). Samples were inoculated into BacT/ALERT standard aerobic and standard anaerobic blood culture bottles, which were transferred to the Bactec 9240 instrument (software version V4.70A) for monitoring the bacterial growth. Positive blood cultures containing Gram negative rods and Gram-positive cocci that appeared monomicrobial in the Gram stain were included in the study. In total, 233 consecutive positive aerobic blood cultures were analysed, including 159 cultures with Gram-negative bacilli and 67 with Gram-positive cocci.
Direct identification of bacteria using the VITEK 2 ID system
The bacteria were directly identified using samples from the blood culture bottles that were incubated for 4-24h at 35°C. From each bottle, 3 ml or 9 ml fluid (for Gram positive cocci) were sampled and first centrifuged at 150 g for 10 min in order to isolate blood cells (in the pellet). The bacteria cells were then harvested by centrifuging (at 1000 g for 10 min) a mixture of 2 ml supernatant with 1 ml of 0.45% saline to eliminate residual red blood cells by lysis. A bacterial suspension was prepared by mixing the pellet with 0.45% saline to obtain a concentration of 0.5-0.63 McFarland units using the VITEK Densichek colorimeter (bioMérieux). When no bacterial pellet was observed after the second centrifugation for Gram positive bacteria, 1.5 ml of 0.45% saline and 3 ml of Brain-Heart Infusion (BHI) were added and the tube incubated under shaking at 37°C for 2 h to induce a better growth.
The bacterial (2 ...
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...y bacteria that were correctly identified by the standard method were included in the comparison exercise. The results from the direct identification method were reported as correctly identified, misidentified, and not identified. In the VITEK 2 ID system, Klebsiella pneumoniae subsp. Pneumonia (planticola/terrigena) and K. pneumoniae subsp. ozaenae were considered identical and reported as K. pneumonia.
For the susceptibility testing, the results of the direct method were classified in four groups: category agreement (complete agreement between the two methods), minor discrepancy (susceptible or resistant by the direct method and intermediate by the standard method or vice versa), major discrepancy (resistant by the direct method but sensitive by the standard method) and very major discrepancy (sensitive by the direct method but resistant by the standard method).
The first day an unknown sample was assigned to each group of students. The first test applied was a gram stain to test for gram positive or gram-negative bacteria. The morphology of the two types of bacteria was viewed under the microscope and recorded. Then the sample was put on agar plates using the quadrant streak method for isolation. There were three agar plates; one was incubated at room temperature, the second at 30 degrees Celsius, and the third at 37 degrees Celsius. By placing each plate at a different temperature optimal growth temperature can be predicted for both species of bacteria.
The Gram positive bacteria has been nicknamed Posi. The Gram positive species’ morphology includes having an opaque opacity with a smooth margin. The moisture content of the Gram positive species is shiny and the pigmentation is gold. The Gram positive species grows at an optimal temperature of 37°C. The shape of the Gram positive species is a cocci, with an arrangement of grapelike clusters. The Gram positive species’ size ranges from .5-1.5 µm. Oxygen requirement of the Gram positive species is facultative, and has complete lysis of red blood cells. All results are summarized in Table
However with septic shock the symptoms may be worse as the patient may experience tachyeordia and tachypnae, leucocytosis which is a high count of white blood cells, change in metal state for example confusion and hyperglycaemia which is a deficiency of glucose in the bloodstream. The diagnosis for sepsis and septic shock involve using blood cultures which is where bacteria is detected in blood which may have spread from a different part of the body. Blood cultures are taken mostly to be done on new-borns and young children who have the symptoms of sepsis. If the blood culture tests positive there is a bacterial or fungal infection which needs to be treated immediately as it is life-threatening. Also cytokines are used as they can destroy the infection however there is a problem with this diagnosis as excessive production can cause tissue and organ
The purpose of this laboratory is to learn about cultural, morphological, and biochemical characteristics that are used in identifying bacterial isolates. Besides identifying the unknown culture, students also gain an understanding of the process of identification and the techniques and theory behind the process. Experiments such as gram stain, negative stain, endospore and other important tests in identifying unknown bacteria are performed. Various chemical tests were done and the results were carefully determined to identify the unknown bacteria. First session of lab started of by the selection of an unknown bacterium then inoculations of 2 tryptic soy gar (TSA) slants, 1 nutrient broth (TSB), 1 nutrient gelatin deep, 1 motility
Cultures on vaginalis agar exhibited many short gram-negative rods. A medium containing starch showed more pleomorphic, gram-variable, clumped, and beaded cultures. 48 hour cultures of patients’ blood specimens with G. vaginalis were reported as mostly gram-positive (Catlin, 1992). G. vaginalis is beta-hemolytic on media containing human or rabbit blood but not on sheep blood agar. Hemolysis is improved by anaerobic incubation.
The purpose of this project was to identify unknown bacteria species from a mixed culture. The two unknown species were initially plated onto Tryptic Soy Agar (TSA), Eosin Methylene Blue (EMB), Mannitol Salt Agar (MSA), and blood agar plates to distinguish between the two different bacteria using colony size, color, shape, and growth characteristics. By identifying and inoculating the differing types of colonies, the two unknown bacteria were purified and able to be tested
Rello, J., Kollef, M., Diaz, E., & Rodriguez, A. (2000).Infectious diseases in critical care. (2nd ed., pp. 352-
I identified the genus and species of an unknown bacterial culture, #16, and I applied the following knowledge of morphologic, cultural and metabolic characteristics of the unknown microorganism according to the laboratory manual as well as my class notes and power point print outs. I was given an incubated agar slant labeled #16 and a rack of different tests to either examine or perform myself; the tests are as follows: Gram Stain; Nutrient Gelatin Test; Carbohydrate Fermentation; Dextrose, Lactose and Sucrose; IMVIC tests; Citrate, Indole, Mythel-Red and Vogues Proskauer test; as well as a Urease and TSI Test.
Hats off to bacteria! This article summarizes that bacteria are good for our body and help us function a lot better. Bacteria live in our guts, in our mouths, and on our skin. Overuse of antibiotics has disturbed the bacterial ecosystem, possibly so much that it is irreversible. In 1999 Lawrence Brandt a professor of medicine and surgery at the Albert Einstein College of medicine had success when trying to help a patient combat diarrhea induced by clostridium difficile. A patient developed diarrhea after taking a course of antibiotics for sinusitis; nothing could shake her C.difficile infection. Brandt reasoned the initial antibiotic treatment had killed gut bacteria that promote digestive health; not knowing which strain to replace, he transplanted stool form her husband. That night she reported marked improvement- for the first time in six months. This procedure has helped patients, but hopefully in the future doctors will be able to administer the particular strain of bacteria that is needed. 99% of the bacteria we harbor are resistant to culture in the lab. It was this impossible to study bacteria until the last decade or so, when DNA sequencing techniques allowed researchers to obtain gene sequences from as little as one bacterial cell. With this researchers found that bacteria cells in our bodies outnumber our human cells. Bacterial exposure throughout our lifetime is needed for our wellbeing, thinking, and functioning, contributing to conditions such as diabetes, obesity, allergies, asthma, and atherosclerosis, as well as to anxiety and mood and cognition disorders. These conditions have become more prominent because of our obsession with sanitation has eliminated the exposure to bacteria humans used to routinely get throu...
wards. Clinical Microbiology And Infection: The Official Publication Of The European Society Of Clinical Microbiology And Infectious Diseases, 18(12), 1215-1217. doi:10.1111/j.1469-0691.2011.03735.x
Nursing diagnosis Hospital acquired infections are spread by numerous routes including contact, intravenous routes, air, water, oral routes, and through surgery. The most common types of infections in hospitals include urinary tract infections (32%), surgical site infections (22%), pneumonia (15%), and bloodstream infections (14%). a. (book). The most common microorganisms associated with the types of infections are Esherichila coli, Enterococcus species, Staphylococcus auerus, Coagulase-negative staphylococci, or Pseudomonas aeruginosa. Urinary tract infections occur when one or more microorganisms enter the urinary system and affect the bladder and/or the kidneys.
In the last decade, the number of prescriptions for antibiotics has increases. Even though, antibiotics are helpful, an excess amount of antibiotics can be dangerous. Quite often antibiotics are wrongly prescribed to cure viruses when they are meant to target bacteria. Antibiotics are a type of medicine that is prone to kill microorganisms, or bacteria. By examining the PBS documentary Hunting the Nightmare Bacteria and the article “U.S. government taps GlaxoSmithKline for New Antibiotics” by Ben Hirschler as well as a few other articles can help depict the problem that is of doctors prescribing antibiotics wrongly or excessively, which can led to becoming harmful to the body.
Infection control is a central concept to every practice of health care providers. Its main objective is to prevent the transmission of infectious diseases from both patients and health personnel (Martin et al., 2010). In dental clinic, infection control is a continuous concern for its professionals. They have to contact patients routinely and be exposed to their blood, saliva, dental plaque and pus that may contain infectious pathogens. It is important for the dental professionals to treat these fluids as if they are infectious and special precautions must be taken to handle them. In this essay, I will highlight the scope of infection control practices in dental clinics and the ways through which infectious microorganisms are transmitted in the dental clinic. Also, I will talk about some infection control guidelines implemented in dental clinics and how they meet the needs of the patients. Finally, from a personal perspective, I will mention some factors that affect the implantation of infection control guidelines and procedures.
Bacterial cells, like plant cells, are surrounded by a cell wall. However, bacterial cell walls are made up of polysaccharide chains linked to amino acids, while plant cell walls are made up of cellulose, which contains no amino acids. Many bacteria secrete a slimy capsule around the outside of the cell wall. The capsule provides additional protection for the cell. Many of the bacteria that cause diseases in animals are surrounded by a capsule. The capsule prevents the white blood cells and antibodies from destroying the invading bacterium. Inside the capsule and the cell wall is the cell membrane. In aerobic bacteria, the reactions of cellular respiration take place on fingerlike infoldings of the cell membrane. Ribosomes are scattered throughout the cytoplasm, and the DNA is generally found in the center of the cell. Many bacilli and spirilla have flagella, which are used for locomotion in water. A few types of bacteria that lack flagella move by gliding on a surface. However, the mechanism of this gliding motion is unknown. Most bacteria are aerobic, they require free oxygen to carry on cellular respiration. Some bacteria, called facultatibe anaerobes can live in either the presence or absence of free oxygen. They obtain energy either by aerobic respiration when oxygen is present or by fermentation when oxygen is absent. Still other bacteria cannot live in the presence of oxygen. These are called obligate anaerobes. Such bacteria obtain energy only fermentation. Through fermentation, different groups of bacteria produce a wide variety of organic compounds. Besides ethyl alcohol and lactic acid, bacterial fermentation can produce acetic acid, acetone, butyl alcohol, glycol, butyric acid, propionic acid, and methane, the main component of natural gas. Most bacteria are heterotrophic bacteria are either saprophytes or parasites. Saprophytes feed on the remains of dead plants and animals, and ordinarily do not cause disease. They release digestive enzymes onto the organic matter. The enzymes breakdown the large food molecules into smaller molecules, which are absorbed by the bacterial cells. Parasites live on or in living organisms, and may cause disease. A few types of bacteria are Autotrophic, they can synthesize the organic nutrients they require from inorganic substances. Autotrophic bacteria are either photosynthetic or Chemosynthetic. The photosynthetic bacteria contain chlorophyll that are different from the plant chlorophyll. In bacterial photosynthesis, hydrogen is obtained by the splitting of compounds other than water.
A biofilm is a layer consisting of various combinations of many different organisms, autotrophic and heterotrophic. They are dense, organized communities of cells, encased in a self-produced slime. The bacteria grow together in water like atmospheres, attaching to a solid surface, forming a small ecosystem. Biofilms are known as a micro-environment, a micro-habitat, or a slime matrix. They help decompose dead organisms and recycle carbon and nutrients.