Microbiology Lab Report Essay Example

Microbiology Lab Report

Microbiology Lab Report

Report Forms 1, 2 & 3

. 2006)Speers, is gram +ve (coli in the fecal and 1st vaginal samples because for instance E. coli and ruling out E. Oxytoca spp and K. SalmonellaThe characteristics that allowed determination of the present microbes include the ability of the microbes to ferment or produce specific gas with various biochemical test media, the morphology of the microbes, and the type of growth of the microbes on various growth media. Normally, cellular morphology tests such as gram stain examine the shape and other characteristics of bacteria, while antibiotic susceptibility/resistance tests are used to test efficacy of various antibiotics on various microorganisms. Biochemical tests determine specific chemical characteristics of specific microorganisms. The results helped in identifying

Report Form 3

A possible antibiotic treatment for the 1st patient is Chloramphenicol 30μg/ml. The sensitivity was expected because Chloramphenicol 30μg/ml has the capacity to inhibit bacterial synthesis through binding to the 50s ribosomal subunit and it also blocks the peptidyltransferase reaction. For the 2nd patient the possible antibiotic treatment is Tetracycline 30μg/ml. sensitivity of Tetracycline is expected because it inhibits protein synthesis in bacteria. Tetracycline For the 3rd patient, a possible antibiotic treatment is Cephalothin 30μg/ml. Sensitivity ofCephalothin is expected because it also inhibits bacterial protein synthesis. Resistance of Ampicillin 10μg/ml and Clindamycin 2μg/ml could be due to inactivation of the antibiotics due to prevention of access to target through changing the outer membrane permeability, modification of the antibiotic by the bacteria (Tang 1997).

Report Form 4

The characteristics of the normal flora that could be determined include gram reaction, cellular morphology, size/pigmentation/margins/height of the colonies, Gross morphology and cellular arrangement. The characteristics of the normal flora from behind the ear were expected because the skin flora is normally predominated by gram +ve microorganisms and characteristics allied to gram +ve microorganisms. The possible identify of microorganism behind the ear is Staphylococcus epidermidis. The characteristics of the normal flora from the gum were expected because the characteristics identified Staphylococcus species and Streptococcus salivarius, makes up 98 percent of the bacteria in the mouth. The possible identify of microorganism from the gum is Streptococcus salivarius (Tannock, 2008)

Report Form 5

Both the hand wash and the soap had the same efficacy in reducing microbial growth as per results and this is because the soap suspended microorganisms and mechanically removed the microorganisms while the hand wash has disinfectant characteristics that reduce the microorganisms (Langley, 2002). My results relatively correlated with the class results.

Report Form 6

An increase of turbidity was observed in the tube of the chemical agents with dilution increase while there was increase in microbial growth with increase of serial dilution of the chemical agent. Increase in turbidity and microbial growth was observed with increase in dilution. Normally, the turbidity of a liquid medium increases with the multiplication of bacteria while the number of colonies on plate reflect the number of microorganisms. Basically, chemical agents with the lowest dilutions are the most effective in killing and removing microorganisms.

The most effective chemical agent was Floor Cleaner because it indicated the least turbidity and plate microbial growth with increased dilutions. The MIC for all chemical agents was dilution one (Andrews, 2009).

Floor cleaner, surface spray, ethanol and vinegar are bactericidal chemical agents while the bleach (sodium hypochlorite) and NaCl are bacteriostatic chemical agents. This was determined because the Floor cleaner, surface spray, ethanol and vinegar eliminated the microorganisms completely by killing with the 1st dilution while bleach (sodium hypochlorite) and NaCl seems to have prevented the microorganisms from growing (Andrews, 2009).


Andrews, J. 2009, General principles of antimicrobial therapy: Infectious Disease: Pathogenesis, Prevention and Case Studies. London, Wiley-Blackwell.

Langley, J. 2002, From soap and water, to waterless agents: Update on hand hygiene in health care settings, Can J Infect Dis,
13(5): 285–286.

Speers, DJ. 2006, Clinical applications of molecular biology for infectious diseases, Clin. Biochem, 27:39–51.

Tang. Y. 1997, Molecular diagnostics of infectious diseases, Clin. Chem, 43:2021–2038.

Tannock, G. 2008, Normal Microflora, London, Chapman and Hall.