The Existing Difference among the Staphylococcus Species - Literature review Example

Microbiological Practical Report Name: Unit: Course: Submission Date: Abstract This report focuses on Staphylococcus and Micrococcus differentiation in line with Staphylococcus species identification, disc diffusion antibiotic susceptibility test, lactose-fermenting Enterobacteriaceae identification, and Gram morphology. The species of Staphylococcus are the main contributors to human disease pathogens and antibiotics resistance reservoirs. Therefore, it is important for researchers to determine and isolate the species with reference to those of medical significance. To achieve its objective, this report uses two members from the lactose-fermenting Enterobacteriaceae; Escherichia coli and Klebsiella pneumoniae. These species were chosen following their clinical relevance in the world today. K pneumonia together with other species crossly related are known to cause nosocomial and epidemic infections among intensive care unit patients in the clinical setting. It is a challenge defining the microorganism from E.coli following the fact that they can both realize indole from tryptophan. Nevertheless, E. coli has its uniqueness in that it is a gas former. Introduction Guentzel, (2008) the family of the Enterobacteriaceae is made up of lactose-fermenting coliforms with such examples like Escherichia coli and Klebsiella Pneumoniae. Shigella and Salmonella make up additional members of the family. Of significance with these organisms, is that they resist bile reactivity within the ileum. Therefore, to help understand their existence within the digestive system, biochemical tests are performed such as Voges-Proskauerand Indoletests, Citrate utilization and Methyl red making the procedures of clinical importance. It is following this fact that it remains fundamental to differentiate these microorganisms. This report was done to help in defining Escherichia coli and Klebsiella pneumonia and establish their differences. The experiment in this report did use colonies characteristics, morphological observations and biochemical tests methodology. There exists a unique difference between the Micrococcus and Staphylococcus where the former are innocuous while the latter are pathogenic. Hence, in order to differentiate the species of Staphylococcus following their pathogenic nature a battery test is used. Therefore, the objective of the second part of this report is to define Microccocus and Staphylococcus, define enterobacteriaceae varieties which have lactose-fermenting characteristics, carry out a disc diffusion susceptibility test and record Staphylococcus species. Materials and Methods Micrococcus and Staphylococcus differentiation In reference to quizlet Inc, (2016), (BIOL2310 Practical Manual) pp29-39 and Webmedia.unmc.edu (2008 and 2011) for gram morphology. Lactose-fermenting Enterobacteriaceae Identification Kavitha, (n.d.) pp 35-39 for lactose fermenting Special strips were used to carry out the experiment. Nutrient agar was used for the study group while control microorganism remained on the strip. Sterile mineral was placed on one tube while the other tube we placed E. coli. The tubes had Leifson and Hugh media. Disc diffusion antibiotic susceptibility test Page 75 of the practical manual (BIOL2310 Practical Manual Staphylococcus species Identification In reference to quizlet Inc, (2016), (BIOL2310 Practical Manual) pp29-39 and Webmedia.unmc.edu (2008 and 2011) for gram morphology. Results Lactose-fermenting Enterobacteriaceae Identification Kavitha, (n.d.) pp29-34 for Voges-Proskauerand Indoletests, Citrate utilization and Methyl red making Table 1: Klebsiella pneumoniae and Escherichia coli biochemical tests results E. coli K. pneumoniae Colony characteristics NA/HBA MCA Growth anaerobically Large flat white Lobate Colony with lobate edge Growth Large flat pink Lobate colony Small flat pink Colony which has lobate edge Large circle white Mucourd flate Colony, Smooth Large flat pink Circular Mucoid colony Not tested Gram morphology +ve +ve Glucose of acid aerobically: Acid aerobically Acid anaerobically Type of energy metabolism + + Oxidative Oxidase -ve Blue+ve Motility +ve -ve Indole production Conventional test Rapid spot test -ve +ve -ve Citrate utilization green –ve -ve +ve Kligler: acid from glucose Acid from lactose Gas production H2S production +ve +ve +ve -ve +ve +ve -Ve -ve Urease -ve +ve Mthyl red (PH≤4.2) +ve __ Voges-Proskauer (acetoin production) -ve +ve Lysine decarboyylase +ve +ve Ornithine decarboxylase +ve -ve Despite the fact that is possible upon observing the Brownian motion seen in the experiment to define the E. coli motility, it is difficult to differentiate these organisms growth using different media. The observed color change to blue in the K. pneumonia culture medium was following the utilization of the citrate to supply carbon forming alkaline products. In the E. coli medium the red coloration production was as a result of tryptophan production. Importantly, none of the reactions did produce hydrogen peroxide gas using the Kligler analysis. Further, while E. coli utilized both sugars it produced gas while the K. pneumoniae did use lactose and there was no gas formed. Subsequently, ammonia was present only among the colonies of K. pneumoniae, hence forming a pink color. Micrococcus and Staphylococcus differentiation Table 2: Micrococcus luteus and Staphylococcus species observation on various media. Culture NA MCA HBA O2 HBA AnO2 Micrococcus luteus 250C, 48h Growth present Yellow Circular Convex Shing Growth present Green-yellow Circular Convex Shing Growth present Yellow Undulated Flat Shing No growth Staphylococcus aureus 370C, 24 h Growth present White Circular Flat Shing Growth present Organism-yellow Circular Convex Smoothened Shing Growth present Grey Undulated Flat smooth Shing Growth present Grey Circular Convex Smooth Staphylococcus epidermidis 370c, 24h Growth present Crimish-white Ciycular Flat Smooth Growth present Light pink Circular Smooth Shing Convex Growth present Grey Flat Circular Flat Smooth Growth present Grey Undulated Convex Smooth Shing Staphylococcus haemolyticus Growth present White Circular Convex Smooth Shing Growth present Pink formation Circular Convex Rough Shing Growth present Grey Flat Circular Smooth Shing Staphylococcus saprophyticus 370C, 24h Growth present White Convex Smooth Shing Growth present Pink formation Smooth Shing Table 3: Staphylococcus aureus and Micrococcus luteus biochemical tests results Staphylococcus aureus Micrococcus luteus Gram morphology +cocci +cocci Colonial morphology (HBA or NA) Growth O2 Growth AnO2 NA: orange, irregular 2-3 mm, flat HBA: grey, flat, opaque 3mm-4mm + Small + NA: yellow, irregular, gassy, convex, opaque. HBA: yellow, irregular, opaque, gassy, convex + No growth - MCA Bile tolerance Growth + Growth + Catalase production (H2O2) + + Baird-Parker glucose of Acid aerobically Acid anaerobically Type of energy metabolism + - Oxidation and fermenting + - Oxidatives (strict anaerobic) Susceptibility/resistance to Bacitracin Furazolidone R S S R Observing from table three the two organisms’ grew in NA and HBA media, but failed to grow in anaerobic medium. Staphylococcus species identification Brown, Edwards, Hawkey, Morrison, ……..Wren, (2005) for coagulase tests. Table 4: S. aureus, S. epidermidis, S. saprophyticus and S. haemolyticus biochemical tests results S. aureus S. epidermidis, S. saprophyticus S. haemolyticus Slide coagulase test (bound coagulase Tube coagulase test +ve + -ve - -ve - -ve - Acid/gas from mannitol +ve -ve - - - - - - Susceptibility/resistance to novobiocin S S R S Production of DNase +ve -ve - - Urease +ve + + -Ve Yellow KEY: +=Positive; -= Negative; S=sensitive and R= Resistance From table four, S. aureus formed coagulase. S. aureus (CoPS) is the leading cause of most of nosocomial infections globally (Bastos, Coutinho and Varella, 2010). Discussion From the experiment most results were accurately obtained. In reality, the K. Pneumoniae digests both glucose and lactose. Also (webmedia.unmc.edu, 2008), the experiment did not define the existing difference between Micrococcus and Staphylococcus, rather the test did establish that Micrococcus were strictly anaerobic and the Staphyloccocus were fermentative and oxidative. Further, only S. aureus did show positive reaction to both coagulase and DNase tests were used. On the other hand, only S. haemolyticus among the experimental species that indicated negative reaction using the Urease test. Also, only the S. saprophyticus strain did survive the novobiocin test. According to (webmedia.unmc.edu, 2011) S. saprophyticus is shown to resist novobiocin an indicator or urinary tract infection in urine cultures. This was well observed in the above experiement showing the credibility of the results obtained. Novobiocin resistance or reactivity within the Staphylococcus species is determined by the variations on GyB gene. Further, (webmedia.unmc.edu, 2011) Staphylococcus saprophyticus is the second most causative agent of the urinary tract cystitis infections among young women with E. coli leading. Otto, (2010) S. epidermis is classified in the coagulase-negative staphylococci (CoNS) cluster that can be differentiate from other coagulase-positive staphylococci like S. aureus as its enzyme coagulase is absent .Hence, the existing literature is apparently the most reliable form of information. From the study, K. pneumoniae and E.coli there were distinctive traits identified via ornithine decarboxylase test, indole production, oxidase, acetoin production and urease while Lysine decarboyylase gave positive reaction to both species, making the former five mechanism significance for differentiating these microorganisms. Conclusion This experiment aimed at establishing the existing difference among the Staphylococcus species. Further, the study aimed at differentiating E. coli and K. pneumoniae. To study the differences among the Staphylococccus species, the experiment did use coagulase, novobiocin, Urease and DNase. Form the study S. saprophyticus was the only species in the Staphylococcus genus that was found to have unique definable traits. This is because using the novobiocin test the species showed susceptibility. Further using Klinger test, it was possible to define the traits of E. coli from K. pneumoniae as the latter was a gas former and thus gas formation was realized. References Bastos, M. C. F., Coutinho, B.G. & Varella, M.L. (2010). Lysostaphin: a staphylococcal Becteriolysin with potential clinical implications. Pharmaceutical Journals, 3:1139-1161. Brown, D.F.J., Edwards, D.I., Hawkey, P.M., Morrison, D. ……..Wren, M.W.D. (2005). Guidelines for the laboratory diagnosis and susceptibility testing of methicillin-resistant staphylococcus aureaus (MRSA). Journal of Antimicrobial Chemotherapy, 56:1000-1018 Guentzel, M.N. (2008). Chapter 26: Escherichia, Klebsiella, Enterobacter, Serratia, Citrobacter and Proteus. Medical Microbiology, 4th edition. Kavitha, R. (n.d.). Chapter-5: Isolation and Identification of Bacteria. Department of Pharmaceutic SRM college of pharmacy Kattankulatur. Retrieved 5/9/16 from, http://www.srmuniv.ac.in/downloads/ISOLATION_AND_IDENTIFICATION.pdf. Otto, M. (2010). Staphylococcus epidermis-the “accidental” pathogen. Nat Rev Microbiol, 7(8): 555-567. Quizlet Inc, (2016). Gram Stain and Morphology. Retrieved 5/9/16 from, https://quizlet.com/9972798/gram-stain-morphology-flash-cards/ Webmedia.unmc.edu (2008). Micrococcus Species. Retrieved 5/9/16 from, http://webmedia.unmc.edu/alliedhealth/CLS/CLS418%2008/StaphylococcusDemos.pdf Webmedia.unmc.edu. (2011). Staphylococccus and other related species. CLS 418 Clinical Microbiology 1. Retrieved 5/9/16 from, http://webmedia.unmc.edu/alliedhealth/CLS/CLS418%2011/Staphylococcus%202011%20Lecture%20Handout.pdf Read More