A Research Study On Enterococcus Faecalis

Bacteria are ubiquitous; they can be found on the skin, in the soil, and inside the body. Because of the very nature of this ubiquity, it is important to be able to determine between different strains of bacteria. An example of this is determining the causative agent for a disease so that the patient will be treated with the appropriate antibiotics. It may be important to determine the bacteria in a certain region, because like with enteric bacteria, it is normal to find them in the digestive tract as they are in a symbiotic relationship with our bodies in this area; however, they also cause opportunistic infections in places outside of the digestive tract to our detriment, such as with a urinary tract infection. Some strains of bacteria are common to nosocomial infections, and identifying these bacteria as such helps create the guidelines for healthcare workers in antiseptic technique. All of the morphology and characteristics of each strain of bacteria help us to better understand the role of bacteria in the body as well as helps us understand how they can cause illness, and what treatment regimen to set in place. In lab this semester, a sample of unknown

faecalis has a low pathogenicity (scilo), it is a virulent, opportunistic pathogen to be reckoned with and is thought of as a super-bug. This is not only due to its ability to resist a variety of antibiotics, but also its ability to travel and employ biofilm formations. It can grow and adapt in many different environments. It can thrive in a wide range of temperatures and has disregard whether salt or oxygen are present, or whether the pH is basic or acidic. Its resilience on inanimate objects makes it a perfect candidate for transmission to occur within the hospital environment from hand to instrument, but it can also be spread via hand-to-hand contact and from food contamination (Public Health Agency of

As the flowchart shows, a series of tests were conducted to identify the unknown bacterium #65. Microscopic observation of the gram stain indicated a gram-positive coccus bacterium. S. epidermidis was used as the gram-positive control while E. coli was used as the gram-negative control. This observation led to the elimination of all gram negative and rod-shaped genera: Enterobacter, Citrobacter, Klebsiella, Escherichia, Pseudomonas, Serratia, Alcaligenes, Neisseria, Proteus, Salmonella, Shigella, Erwinia, Veillonella, Flavobacterium, Bacillus, Arthrobacter, Lactobacillus, Listeria and Kurthia (2). By performing the catalase test, it was determined that the bacterium was catalase negative and it did not produce bubbles. M. luteus and E. faecalis were used as positive and negative controls, respectively.

The purpose of this experiment is to distinguish and indentify an unknown bacterium. There are several tests that can help one eliminate and narrow down the options. The most useful test, and the very first one done, is a gram stain. This test will tell whether the bacterium is gram-positive or gram-negative. After the type of gram stain is identified, the tester has a wide array of differentiating tests at their disposal. Based on the results from these tests, and the numerous others that are available, one can accurately establish the identity of an unknown bacterium.

In the world of microbiology it is vitally important to be able to discern the identities of microorganisms. Not only is it important in a lab setting but as well as in healthcare in general. Properly identify what strain of bacteria a person has will aid in the proper medicine and dose given. Throughout the semester we have learned about different types of bacteria and certain test that can clearly identify them. The purpose of this lab report is to identify a Gram-positive or Gram-negative bacterium. Using all the knowledge of procedures and lab techniques identify the unknown and discuss all the tests you performed.

Bacteria, single-cell microorganisms, are found all over the planet. Some can be beneficial to their enviroment, while others can be pathogenic. Enterococcus faecalis is a resilient bacterium that resides in the intestinal tract of humans and mammals. Due to their ability to colonize at a rapid rate, E. faecalis cause a multitude of infections. To determine an unknown bacteria, one gram stain and two biochemical tests, a catalase and RBC hemolysis test, were performed. The gram stain showed gram-positive cocci bacteria, which lead to the catalase test. The test for

The bases of this experiment was to discover the identify of the unknown from three possible specimens: Klebsiella pneumonia, Escherichia coli, and Enterobacter aerogenes. Utilizaing the T streak technique, the bacteria was isolated into pure colonies for further study. The Gram Stain method was used to identity the morhphology of the bacteria such as the shape and whether the bacteria was Gram positive or Gram negative. Biochemical test were also used to help identify the unknown bacteria. The biochemical test used was the Triple Sugar Iron Agar, Sulfur Indole Motility test, Methyl Red test, Voges-Proskauer test, Citrate test, Urease test, and the Gelatin test. After observing the morphology of the bacteria using the Gram Stain method and utilizing all the possible biochemical test, the bacteria was identified to be Enterobacter aerogenes.

The genus Streptococcus is classified as a gram positive bacteria because of the spherical or ovoid cells that often arranged in pairs and the color it turns too after undergoing the gram staining technique. Unlike the catalase positive genus Staphylococcus, Streptococcus is catalase negative (Fox). Many Streptococcus bacteria are known to be facultative anaerobes, meaning they prefer to grow in places that have no oxygen but will adjust to places that contain some oxygen (Holt, et al.). On the contrary, there are a handful of Streptococcus bacteria that are considered to be obligate anaerobes, meaning they are strictly prohibited from being around oxygen because they are unable to live. Growing this type of bacteria includes specific factors

Enterococcus faecium has been a leading cause of multi-drug resistant enterococcal infections over Enterococcus faecalis in the United States. Approximately 40% of medical intensive care units reportedly found that the majority, respectively 80% and 90.4%, of device-associated infections (namely, infections due to central lines, urinary drainage catheters, and ventilators) were due to vancomycin- and ampicillin-resistant E.faecium. [6]

Bacteria can be found on numerous locations of the human body, while some are beneficial to human health others are not. Upper respiratory tract infections for example can be cause by pathogenic bacteria. Left untreated, respiratory infections can be harmful or even fatal in some cases. Therefore, identifying the cause of the infection is paramount. Knowing the target would allow the correct treatment methods to be utilized, such as the use of an effective antibiotic. The purpose of the experiment was to identify a bacteria of interest that has presumably caused an upper respiratory tract infection. Furthermore, the goal was to use as few test as possible to produce quick yet accurate results which could be vital in a real world situation

aeruginosa is one of the most common isolated strains exhibited natural resistance to antibiotics, in addition to its ability to develop resistance to further drugs (Yezli et al., 2014). A gram-negative Escherichia coli colonizes the gastrointestinal tract of human as normal flora and some of them acquired a virulence features that confers their ability to cause infections (Croxen et al., 2013). It is a major cause of urinary tract, enteric diarrhoea and systemic infections as bacteraemia, cellulitis, nosocomial pneumonia, infectious arthritis, peritonitis and the leading cause of neonatal meningitis (Pitout, 2012). Recently, E. coli has a global dissemination as one of the most predominant isolates with resistance to β- lactam and other antibiotics (Yezli et al., 2015). Enterococcus species are gram-positive cocci spread in an intestinal tract, airways, skin and other mucosal surfaces that the most important species are E. faecalis and E. faecium (Savini et al., 2012). Enterococci become one of the infection sources acquired in hospitals that cause urinary tract infections, bacteraemia, endocarditis, wound infections, meningitis as well as intraabdominal and pelvic infections (Agudelo Higuita and Huycke,

Bacteroides fragilis constitute 1% to 2% of colon resident microbiota and achieving approximately 30% of the total of organism cultured from feces (1-3) . Members of genus Bacteroides are important opportunist anaerobic pathogen(4). In this genus Bacteroides fragilis due to its virulence factor such as, adhesions, hemagglutinin, polysaccharide capsule and fimberia is considered to be the most virulence pathogen(2, 5). This organism isolates from exteraintestinal monomicrobial and mixed infections such as diabetic foot infection, brain, lung, intera abdominal, Intera pelvic abscesses, surgical site infections and sepsis(6-9). As well as this organism cause toxin dependent diarrheal disease in human. This bowel disease is one of the most important causes of morbidity and

Enterococcus faecium is an ESKAPE pathogen that is one of the leading causes of nosocomial infections not only in the United States of America, but throughout the world. ESKAPE pathogens in general are problematic because they are antibiotic resistant to many of the drugs that are available, therefore making them one of the greatest challenges that clinical practice settings experience today

Enterococci are gram positive cocci that can occur singly, in pairs or as short chains. They are facultative anaerobes, possessing the ability to grow in the presence or absence of oxygen. Enterococci can withstand harsh environmental conditions. There are currently 23 enterococci species and they are divided into five groups based on their interaction with mannitol, sorbose and arginine 5 .E. faecalis can survive extreme challenges. Its pathogenicity ranges from life-threatening diseases in compromised individuals such as bacteremia, septicemia, endocarditis, and urinary tract infections to less severe conditions, such as infection of obturated root canals with chronic apical periodontitis.The persistence of E.faecalis might be due to the

Hemolysis test was performed according to the method described by Guttmann and Ellar (2000). Overnight cultures of isolated Enterococcus durans and Enterococcus hirae were streaked on blood agar and incubated at 37°C for 24 h. Blood agar plates were examined for signs of hemolysis. Blood hemolysis test was performed in duplicates.