The primary goal of this investigation was to determine whether bacteria commonly isolated as a pair from contact lens cases could coaggregate or cohere. The organisms were used in this study was isolated from the contact lens cases of asymptomatic daily wearers and stored in culture stock. The primary outcome of this study demonstrated that coaggregation and cohesion occurred between Acinetobacter spp, Staphylococcus spp and Micrococcus spp. Two Gram positive bacteria, Staphylococcus spp and Micrococcus spp also showed coaggregation. But, Acinetobacter spp and Micrococcus spp showed sporadic coaggregation. However, no coaggregating pairs exhibited the high scores given by the positive control paring of A. naeslundii and S. sanguinis, which …show more content…
Indeed, this study showed the evidence that when Staphylococcus spp grown together with Acinetobacter spp or Micrococcus spp, could influence the growth of Staphylococcus spp. Additionally, Staphylococci influenced the growth of Acinetobacter spp, but mixed response was seen with Micrococcus spp.
Swartz et al (1987) demonstrated coaggregation and cohesion with dental plaque bacteria, where Actinomyces viscosus foster the biofilm establishment of Bacteroides gingivalis on teeth by enhancing its adherence. Similarly, the present study finding showed that the contact lens case isolates, Micrococcus spp and Acinetobacter spp can influenced the adherence of Staphylococcus spp in the contact case surface. Staphylococcus spp. identified as the most commonly from the contact lens cases in asymptomatic wearers, also reported as the most commonly found as a part of the normal ocular flora (eye lid, conjunctiva) or extra-ocular microbiota (facial) and elsewhere on human body8,14 Along …show more content…
Thus we sought to determine whether those bacteria that produced coaggregation were associated with cohesion in contact lens case biofilm formation. Cohesion can also occur when a pioneer species modifies the substratum to encourage adhesion of successor species. As, Staphylococcus spp are the most commonly isolated from the lens cases, could be considered as pioneer species, but 10% of the lens cases also showed the contamination of Gram negative bacteria. Based on recent in vivo data we found Staphylococcus spp often isolated with Acinetobacter spp. There is other literature which also showed the isolation of P. aeruginosa and S. marcescens from lens cases. The present study showed cohesion between Staphylococcus spp and Acinetobacter spp/ Micrococcus spp, where Staphylococcus spp can be considered as pioneer species and Acinetobacter and Micrococcus as successor. Whist this study did not investigate the facilitating factor for the cohesion, will be worth to consider in future study. The next step will be to see whether the elimination of Micrococcus and Acinetobacter contamination from lens cases will reduce the adhesion of Staphylococcus spp which may reduce the overall rate of contact lens case
Click here to unlock this and over one million essaysGet Access
This experiment was conducted to find the genus and species of an unknown bacteria prescribed by the lab teacher, which was unknown bacteria GA3 in my case. Identification of unknown bacteria techniques are used on an every day basis to figure out what type of bacteria it is and to find the best method of how to treat a patient with this bacteria (1). All five “I’s” of Microbiology were used in the testing for the unknown culture. Inoculation was used several times to put the unknown culture into agar plates or into biochemical test tubes. After Inoculation of these tubes or plates, they always were placed into the incubator for further growth and development. Isolation was used to make sure we got the correct bacteria we were testing for. After each further isolation, we gram stained the culture and inspected the culture under a microscope to further help in the identification process of the unknown bacteria. Multiple tests were done on the unknown culture to make sure we were confident in what kind of bacteria the unknown was.
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
For this experiment, I utilized unknown number three which I later identified as Staphylococcus epidermis. I concluded that the unknown organism was Staphylococcus epidermis based on numerous tests performed in the laboratory which I will discuss in detail throughout this paper. One of the first tests performed was the Gram Stain. The Gram Stain
After gaining some knowledge about bacteria, we were giving an investigating bacteria growth lab to do. Our objective was to observe the conditions required for bacteria to grow and to test the effectiveness of substances that may be antibacterial, disinfecting, and or sanitizing. My group and I began our procedure by gathering all the bacteria by swabbing our necks and mouths. After this, we inoculated the culture by rubbing the bacteria on the agar, a nutrient rich gel made from sea kelp, on the bottom side of the container where we grow bacteria, the Petridish. We hoped for the results to come back with little or even no colonies and an immense zone of inhibition around the tiny circle cut out of filter paper covered in toothpaste, Neosporin, and Chlorhexidine Gluconate 4% Solution.
The purpose of this experiment was to isolate and identify an unknown Staphylococcus species based on its morphological and biochemical profile (Alachi, 2006). The Staphylococcus genus consists of Gram-Positive bacteria, arranged in grape-like clusters. These species are common residents of the skin and mucous membranes of humans and animals. Majority of Staphylococci are catalase-positive, oxidase negative, aerobic and facultatively anaerobic, and non-motile. They are considered opportunistic pathogens and cause roughly 80% of suppurative skin diseases (e.g., boils). Many Staphylococci
Pseudomonas aeruginosa is a key opportunistic pathogen characterized by high-level antibiotic resistance and biofilm formation (1).Biofilm is a structured community of bacterial cells enclosed in a self-produced polymeric matrix adherent to an inert or living surface. Biofilmproducing organisms are more antimicrobial resistant than organisms without biofilm. In some extreme cases, the concentrations of antimicrobials required to kill biofilm positive organisms can be three- to four-fold higher than for biofilm negative bacteria, depending on the species and drug combination (2). Biofilms have great importance for public health as they are the main cause of nosocomial infections, especially implant-based and chronic infections (3). Antibiotic resistance in biofilms is due to a combination of many factors that act together to result in a level of resistance that is much higher than that of planktonic bacteria (4,5).
Lens case contamination is a well-documented occurrence for contact lens wearers despite the efficacy of contact lens disinfectants. Several microorganisms have a propensity to attach to surfaces and may become more tolerant of disinfection upon attachment. Contact lens case is one of the accessories which become contaminated easily and more prone to biofilm formation. Since last few decades the modification of the biomedical devices has attracted attention and the application of the antimicrobial surface is one of them to eliminate microbial contamination. Silver is an established and proven antimicrobial with efficacy against both Gram positive and Gram negative bacteria. In vitro studies evaluating the antimicrobial efficacy of silver-impregnated
The effectiveness of disease treatment is often presented by the challenge of antimicrobial resistance. Cystic Fibrosis (CF) for example, is a pulmonary infection characterized by the poly-microbial growth of bacteria within biofilms, in the pulmonary tract of humans. For children suffering from CF, Staphylococcus aureus (S. aureus) initially colonizes their airways, which with age, becomes replaced by Pseudomonas Aeruginosa (P. aeruginosa). The eradication of P. aeruginosa by antibiotics fails in 10-40% of CF patients. In the article, it was proven that there existed an interaction between the staphylococcal protein A (SpA) from S. aureus filtrates (SaF, a bacterial supernatant of S. aureus), and an exopolysaccharide (Psl) of P. aeruginosa. This interaction lead to the aggregation and increased resistance to tobramycin¬ – an antibiotic used to eradicate P. aeruginosa, to prevent chronic colonization of the bacteria. The study conducted involved 7 samples of P. aeruginosa that were taken from individuals who underwent successful eradication treatment, and 7 samples from individuals who still had persistent isolates. These P. aeruginosa samples were cultured for 24 hours in media. When SaF was added to the overnight preformed biofilms, the eradicated isolates were not affected by the SaF; however, the persistent isolates showed significant reduction is surface coverage due to densely packed cellular aggregation, without affecting the biomass or viability of persistent isolates. The
The most common pathogenic strains that cause wound infection is Staphylococcus aureus (35%), Escherichia coli (15%), Pseudomonas aeruginosa (13%) and other bacteria (37%) (Amit Kumar Gupta et al., 2015). In another study, Staphylococcus aureus has been reported as the major cause of wound infection with (24.2%), followed by Pseudomonas aeruginosa (21.4 %), Escherichia coli (14.8 %) and another different organism (39.6 %) (Jyoti Sangwan et al., 2016). Staphylococcus aureus (Methicillin Resistant Staphylococcus aureus) is gram positive bacteria and can be a lethally opportunistic pathogen or human commensal, it is one of the leading organisms causing a variety of hospital-acquired infection and community acquired infection (Brown et al., 2014). S. aureus has
Staphylococcus aureus is a gram-positive coccal bacterium, 1µm in diameter, forming grape like clusters or clumps, and is the most important pathogen amongst Staphylococci bacteria. A gram stain was performed on unknown bacteria #41, producing a purple, gram positive cocci bacteria appearing in grape like clusters or clumps under microscope. A streak plate test on nutrient agar was performed resulting in yellowish colonies on the nutrient agar. A catalase test was then performed with a positive Staphylococcus result. Mannitol Salt Agar plate was then used to determine between Staphylococcus aureus and Stapylococcus epidermidis.
Bacterial urinary tract infections represent the most common type of nosocomial infections. Often, the ability of bacteria to both establish and maintain these infections are directly related to biofilm formation on indwelling devices or within the urinary tract itself (30). Enterococci (especially E. faecalis) are one of the main causative agents of urinary tract infection and Catheter-associated urinary tract infections (CAUTIs) besides gram-negative pathogens (31, 32). In these infections Biofilm provides a favorable milieu for microbial survival within the host as the organisms are shielded from the host immune response, as well as antibiotics and antimicrobial agents (33, 34). Several studies conducted to introduce main virulence genes of enterococci that are associated with biofilm formation in these bacteria (11, 13,-17), but virulence mechanism and related genes for biofilm formation are not well understood (35). In this study we investigated biofilm formation of clinical enterococci isolates isolated from Urinary tract infections. These strains were characterized for presence of adhesions and secretory virulence factors. Isolates had diverse presence of virulence from lack to highest amount of virulence genes. Several previous studies investigated relation of virulence genes and biofilm formation, especially presence of esp and gel. Enterococci esp has been implicated as a contributing factor in colonization and persistence of infection within the urinary tract
100 μl of 10-5 and 10-6 dilutions of donor cells were each plated onto MacConkey (MAC) agar plates without streptomycin. 100 μl of 10-5 dilution of donor cells and 10-5 and 10-6 recipient were also plated onto MAC plates with streptomycin. 100 μl of 10-4 and 10-5 dilutions of the conjugation mixture cells were plated onto MAC agar with streptomycin. All seven plates were inverted and placed in a 37˚C incubator for about 24 hours. The bacterial colonies on each plate were counted the next day (colony counts seen in Table I).
The bacteria live in the small intestine all healthy people as part of the normal flora. Infection in new born babies occur during delivery, or from bacteria acquired in the hospital or at home. Premature or low weight babies are at higher risk of contracting
Nutrient Broth and Nutrient Agar were used to inoculate bacteria taken from different surfaces. Nutrient agar plate was inoculated with a sample taken from skin surface. A sterile cotton swab was first immersed on sterile water, then, rubbed against the skin with swirling motion and transferred to an agar plate by rubbing
Results: Fourteen patients had a unilateral corneal abscess. The average age was 46.28 years. Was male predominance. The average period of consultation was 7 days. The average length of hospital stay was 19 days. A risk factor was identified in 78.5% of cases with contact lens wear (21.4%), the closed eye injury (21.4%) and eye surgery (14.2%). The removal of corneal helped isolate the causative organisms in 78.5%, coagulase negative Staphylococcus and Pseudomonas aeruginosa were the species most frequently encountered. All patients received broad-spectrum antibiotics after appropriate to the sensitivity. The anatomical evolution was good for 13 patients (92.8%), with one case of evisceration.Functional recovery after treatment was good for one patient and seven patients were scheduled for a cold corneal