Characteristics Of Isolates

Three ways to assess water are positive/negative, membrane filtration and IDEXX Colilert and Enterolert assays. For membrane filtration, petri dishes and an incubator are used. For IDEXX coliert powdered medium is used for total coliform and E. Coli, while Enterolert media is used for enterococci. Also an incubator, colilert trays are used. IDEXX is more expensive than membrane filtration.

Using the information found in the Gram Negative Enteric Baccilli and Gram Positive Cocci Reference books,

AIM – The aim of the experiment is to determine the relative effectiveness of several anti-microbial substances on developing pathogens. (E. coli)

The IMViC test is a series of different tests that differentiate between enterics. One is the Indole test. This test tells whether the bacterium possesses tryptophanase which is the enzyme that breaks down tryptophan into indole. The agar contains tryptic soy broth so if the bacterium contains tryptophanase, indole is produced. This production of indole is seen by adding Kovac’s reagent which causes a red ring to be seen at the top of the tube. The citrate test is also used to see which kind of products the bacteria make. It uses a green agar slant that contains sodium and ammonium phosphate. Bromythymol blue dye is late added as an indicator. Inoculation of the slant with a needle using a zig-zag then stab technique was used with the gram positive bacterium. Conversion of the medium to blue is a positive citrate result. All plates, slants, and broths were incubated at 37°C for 24‐48 hours.

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

More than a century ago the notion of microbiota working as a regulator for health and disease was already in use. They realized that consuming large amounts of fermented milk helped with their longevity. This began the foundation of probiotics. However, the oral probiotics that are used today are at a lower amount than what is contained in the colon. After cycling through the digestive system it is

coli were labeled as bacteria that should not be examined or touch without permission from the supervising teacher. Although the strain of E. coli used in this experiment was harmless, to avoid transmitting the bacteria to other organism, the experimenter handled the E. coli for caution (see Appendix H, I, J, K).

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

In our experiment we are using one of three methods to inject the E.coli bacteria with

: In the field of microbiology, there are times when a sample will contain more than one species of bacteria. The goal is to separate each bacterium and culture them independently from one another to identify them. This was the objective of this lab. Each stock contained two unknown bacterium, and the possible unknowns were Eserichia coli, Enterobacter aerogenes, Enterobacter cloacae, Serratia marcescens, Proteus vulgaris, Klebsiella pneumoniae, Shigella flexneri, Shigella sonnei, and Salmonella enterica. The tests available were MacConkey agar, Endo agar, Hektoen Enteric agar, Tryptone Soya Agar (TSA), carbohydrate sugar broths, Triple Sugar Iron (TSI) agar, decarboxylase broths (arginine, lysine, and ornithine), Simmon’s Citrate Agar, urease

Clostridium difficile (C. difficile) is an anaerobic, Gram-positive, bacillus-shaped bacterium that causes the disease Clostridium Difficile Infection (CDI). One of the reasons this particular species is so successful and disease-causing is because it possesses the ability to form spores, which makes it very difficult to eradicate, as these spores are able to survive extreme conditions. C. difficile flourishes in the gastrointestinal tracts of individuals who have been prescribed broad spectrum antibiotics, as these tend to disrupt the normal microbiota. If an individual has previously contracted CDI, the likelihood of future infection(s) is more likely than if it were never contracted, at a rate of ~35%. The aim of this study, which is actually the first of its kind, is to utilize the probiotic Lactobacillus casei Shirota (L. casei Shirota) to attempt to suppress the recurrence of CDI after an initial infection. Probiotics contain a live strain(s) of “healthy” bacteria that help rather than harm an individual, and they work by competing with C. difficile’s

How does the effectiveness of natural remedies ability to inhibit growth of E. coli compare to that of antibiotics?

Phagocytosis and killing of opsonized bacteri were checked by a colorimetric assay according to previously described procedures with some modifications (Fijalkowski et al., 2012; Mehrzad et al., 2009). This experiments wre run in triplicate for each isolated E coli. Brifly, each isolated E coli was opsonized with 10% pooled avian serum for 30 min. The test tube (T) was containe the same volume (500 µL) of heterophiles and opsonized E coli. Test tube was rotated end-over-end at 37 °C for 90 min . The ratio of E coli to hetrophil was 10/1.Control samples (C) contained opsonized E coli, without hetrophil. A 100 µL

The simulated gastric solution consisted of distilled water containing 0.2% NaCl with its pH adjusted to 1.5 by 5 M HCl; the solution was filter-sterilized using a 0.2 mm filter (Cook et al. 2011; Mokarram et al. 2009; Rao et al. 1989). The assay was initiated by transferring the produced beads (uncoated, coated) to 9 mL of simulated gastric solution; the initial cell concentration was approximately 8.8× 1013 CFU/mL and 2 -6 × 1012 (uncoated, coated beads). The suspension was incubated at 37° C; samples were collected at 0, 60, and 120 min and following the incubation, the beads were removed. Viable cells of each bacterium were then enumerated in triplicates using method described in Section 2.5 and the counts were expressed as mean log CFU/mL.

Isolates Enterococcus durans and Enterococcus hirae were tested for their ability to resist low pH values as follow, 25 ml of sterile MRS broth adjusted to pH 6.4, 4, 3 and 2 was inoculated using 1% (v/v) of an overnight culture, then incubated at 37ºC for 6 h. The absorbance at 620 nm was monitored using spectrophotometer (Unico, USA) at hourly intervals (Nawaz et al., 2011).