Background
Oral microbial floras constitute microorganisms that are found in the buccal cavity that may not necessarily cause harm to the human being. These organisms make up the normal microbial flora of the mouth. Because these organisms have to compete for food resources, some in the process end upon being eliminated due to competition. This element of competition may eventually prove advantageous when a pathogenic microbe is eliminated in the process. However, some microorganisms found in the mouth may end up causing undesired effects like dental caries, gingivitis and pyorrhea. These effects are mainly caused when there is an imbalance in the existence of the microbes colonizing the mouth cavity. This imbalance is characterized by the production of acids. These acidic compounds damage the gums and the teeth. The microbes can adhere to the surface of the epithelial cells, tongue, and the enamel. Microbes that colonize the surface of the tooth are commonly known as dental plaque. The microbes that stick on the surface of the epithelial cells and the tooth do so with the aid of a biofilm. Bacterial genera that are known as the primary colonizers comprise Streptococcus, Actinomyces, Neisseria, and Vellionella. Secondary microbes include Prevotella and Fusobacterium spp. Normal microbial flora in the mouth cavity is always at equilibrium. The by-products of growth of some organisms are quite often used by other organisms as nutrients for growth. Some bacteria’s metabolic activities make use of oxygen thereby creating conducive environment for growth of anaerobic bacteria. However, the balance may break down in case the nutrients are higher in sugar content. The bacteria that adhere to surfaces end up lowering the pH of the medium. This creates a favorable environment for acid-loving bacteria growth.
Discussion of the primary research requirement
Several types of research have been conducted on Oral Microbial Flora. Pedreira, Kusahara, Carvalho, Nunez and Peterlini (1) delved into colonization in Children undergoing Mechanical Ventilation. Munro, Grap, Jones, McClish and Sesslar (2) tackles Tooth brushing and Preventing Ventilator-Associated Pneumonia in Critically Ill Adults. Preza, Olsen, Aas, Willumsen, Grinde and Paster (2) study Bacteria Profiles of Root Caries in Elderly Patients.
Pedreira’s (1) objective was to compare the microbial profile in the oral pharynx path, the length of ventilation and the duration of stay in the intensive care unit by children subjected to ventilation process that have history of drug or non-drug oral care. The method used involved randomized control study conducted in a PICU in Sao Paulo, Brazil. The patients or their guardians were given highlights on aims, methods and limitations to be encountered. Of the 146 patients during the 9 months of the study 38 percent took part in the study. Criteria for eligibility were thoroughly interrogated. Children who were in the PICU less than 48 hours were also not allowed to take part in the study. There was random assignment of the children to the two groups of the study. In the experimental group, oral care included the use of an oral gel containing chlorbexidine digluconate 0.12 percent as an active ingredient. The control group was subjected to the same oral care except for unavailability of the antiseptic agent. Gel was given code according to codes to conceal identities. The pharmacist was the custodian of the information pertaining to the identity of the gel types. PICU nurses were trained in oral care by a dentist. Evaluation of child oral status was done. The selection of oral care equipment was done bearing in mind the child’s age. During the training, a description of the required outcome was covered with care taken to avoid interference with the oral and labial mucosa. Children were put in lateral position to avert the possibility of pulmonary aspiration of the secretions. A toothbrush with gel was used to clean the teeth in quadrants. The teeth were cleaned, ventral surface of the tongue was brushed in a posterior-anterior manner. Oral mucosa was rubbed by swab dipped in gel. A total of 56 children took part in the study, with 52 percent being control group and 48 percent in the experimental group. The two groups had similar demographic features, medical conditions, and diseases, drug and nutrient requirements. There was no significant difference in intubation characteristics between the control and experimental groups. The two groups had no disparity in the Nine Equivalents of Nursing Manpower Use Score, oral cavity clinical conditions according to the DMFT index, the health status of the oral mucosa, length of mechanical ventilation or length of PICU stay. After two days of admission, there was notable decrease in microbial invasion in children in the experimental group compared to those in control group that increased. In both, the groups’ Streptococcus viridans was detected in high numbers. Coagulase-negative Staph and Moraxella were notably present after thorough isolation exercise. Gram-negative bacteria were overly predominant. P. aureginosa and A. baumanii were higher in control group than the experimental group and that of K. pneumonia and Enterobacter spp higher in experimental group. Sample totaling 26 had pathogenic bacteria among which some antibiotic-resistant like the K. pneumonia which is resistant to beta-lactamase, methicillin-resistant S. aureus. The buccal cavity can be the origin of the spread of pathogenic organisms to other organs such as lungs. Nosocomial infections are caused by microbes colonizing oral-pharynx path. Inhalation of air containing bacteria, make the microbes spread from different locations of the body. The movement of bacteria takes place in the gastrointestinal tract. Therefore, reduction of bacteria in the oral pharyngeal tract can have effect on oral colonization and the prevalence of respiratory hospital-acquired infections. The difference in colonization by pathogenic bacteria was insignificant between control and experimental entities. There was no difference in microbial activity in the oral cavity by the oral flora between the two groups. E. coli, K. pneumonia, and other species of Acinetobacter were very prevalent. Gram-negative bacteria cause the highest number of infections in adults in ICU. Children in experimental group had more Enterobacter species accounting for 75 percent, E. coli- 100 percent and K. pneumonia-71 percent than in children in control group. Future studies should capture the effects of oral care on development of VAP in infants.
Munro (1) researched mechanical, pharmacological, and oral care on occurrence of ventilator-related pneumonia in patients undergoing mechanical ventilation. In the methodology, patients undergoing treatment in intensive care units were involved in a day of intubation into controlled clinical trials which were randomized. The trials were more of a two by two factorial in design. Edentulous and pneumonia patients did not take part in the study. Patients who had been clinically diagnosed with pneumonia at the onset of intubation were excluded likewise to edentulous patients. A total of 547 patients were assigned randomly to one to four treatments. An oral swab having 0.12 percent chlorhexidine was applied two times a day. Brushing of tooth was done thrice in a day. There was no significant difference in clinical characteristics of the four treatments. Patients, who had no pneumonia initially, contract pneumonia by day three. This becomes 24 percent of those treated with chlorhexidine. After analyzing data on all patients, the outcome indicated chlorhexidine or tooth brushing had no effect. Pneumonia incidence was seen to decrease after 72 hours of use of chlorhexidine. Tooth brushing had no effect on Clinical Pulmonary Infection Score and did not in any way enhance the effects of chlorhexidine. Chlorhedexine, an antibacterial agent that is broad-spectrum in its activity has been used in healthy populations in oral rinsing. It controls dental plaque. It treats and prevents gingivitis. Bacterial resistance to this substance has not been shown in the research and the drug has few side effects. The substance can be used in reducing hospital-acquired respiratory tract infections in patients.
Preza’s (2) research assessed the bacteria that cause root caries in elderly patients by using molecular techniques independent of culture to determine the association of specific bacteria within healthy carious roots. Methodology. Bacterial 16s r RNA genes extracted from DNA were amplified using PCR machine. Cloning and sequencing ensued to know the species identity. Of the 3,544 clones, 245 were prominent. This represented 8 microbial phyla. A large number of species detected are yet to be cultivated. Two men and nineteen female patients were involved in the research. Their mean age was 89 years. Participants were first clinically examined a couple of days before sampling. They were then divided into control group consisting of ten people and RC group having 11 participants. The control groups did not have RC while the RC group had RC lesion during the process of examination. Lesions on exposed root surfaces were treated as carious when they felt leathery. The candidates had to clean their teeth the day before or in the morning before sampling is done. From the non-RC group, plaques from a healthy root, carious root and dentin from the same carious root were used. There was a random sampling of healthy root sites. Plaque samples were picked using relevant apparatus. Root surfaces were aseptically cleaned. With a spoon excavator the layer of infected dentin was taken and the inner side of RC lesion sampled. The samples were put in 300 microliter TE buffer and dipped into frozen ice. This is stored at -80 degrees Celsius. Bacterial DNA was then extracted using QIAamp DNA mini kit. Extracts were then stored at -20 degrees Celsius. The genes were then amplified using universal forward primer. Polymerase chain reaction was then conducted in thin-walled tubes in PCR machine. Two microliters of DNA template were added to the reaction mixture containing each of the primer, deoxynucleoside triphosphates, magnesium ions and platinum taq polymerase. The samples were preheated at 95 degrees Celsius for 4 minutes, followed by 30 cycles of amplification. The solution was denatured at 95 degrees Celsius for 45 seconds, annealed at 60 degrees Celsius for 45 seconds and then elongated at 72 degrees Celsius for 60 seconds with additional 15 seconds for each cycle. In chain elongation step is done at 72 degrees Celsius for 15 minutes. The results were then observed using gel electrophoresis. Cloning was then done using TOPO TA cloning kit. E. coli TOPO10 cells were used to do the transformation. Luria- Bertani agar plates were used to plate the transformed cells. The plates were incubated at 37 degrees Celsius in the incubator. Amplification was done with m-13 primers. Bacterial profiles of the 21 candidates were investigated. A total of 8 bacterial phyla were observed 46 percent of which were cultivable species in a known genus. Fifty-four pr cent sequences have not yet been identified. The Control group had lower number of bacterial incidence on root surfaces. At relatively high clone levels in few healthy subjects were Veillonella, Selenomonas, and S. Gondi. RC group had no bacteria associated with poor health conditions like Kingella oralis, Fusobacterium nucleatum subsp. Polymorphum, Leptotricha spp., Selenomonas noxia. The microflora overlying the root surface in RC subjects had lower diversity than the control sample. On such surfaces, bacteria species like Campylobacter gracilis, Selenomonas spp. The study offers description of microbes associated with rood surfaces in the elderly based on culture-independent method. Of the 21 people who participated in the study, different bacteria profiles were observed. Diversity was less evident when bacteria moved from healthy to diseased individuals. RC group exhibited lowered bacterial diversity on healthy root surfaces. Some species of bacteria were considered important to the health of the candidates because they were never detected. The prevalent bacterial species were Fusobacterium nucleatum subsp. Polymorphum, S. sputigena, Selenomonas and Propionibacterium sp. Strain FMA5. The bacteria associated with RC were more complex than initially imagined. These bacterial species that were detected included S. mutans, lactobacilli and Actinomycetes.
Conclusion
Ventilator-acquired pneumonia needs to be heavily researched to prevent its recurrence. Pneumonia leads to massive loss of lives especially those of the young ones. More funds should be dedicated to the research on pneumonia as it appears to be one of the emerging hospitals acquired infections. This will help the hospital staff to put in place adequate sanitary conditions to help avert its spread. The studies that have been conducted have not conclusively given the specific bacteria that contribute to tooth decay, therefore future areas of research should focus on this area. This helps in knowing the physiological conditions under which such microbes thrive to avoid creating conditions that encourage their growth.
Works Cited
Munro Cindy, Grap, Mary, Jones Deborah, McClish Donna and Sessler Curtis. “Chlorhexidine, Tooth brushing, and Preventing Ventilator-Associated Pneumonia in Critically Ill Adults”. American Journal of Critical Care. 18.5(2009):11.
Pedreira, Mavilde, Kusahara Denise, Werther Brunow de Carvalho, Silvia Cristina Núñez and Angélica Peterlini Maria. “Oral Care Interventions and Oropharyngeal Colonization in Children Receiving Mechanical Ventilation” American Journal of Critical care.18.4 (2009).
Preza, Dorita, Ingar Olsen, Aas Jørn, Tiril Willumsen, Bjørn Grinde, and Paster Bruce. “Bacterial Profiles of Root Caries in Elderly Patients”. Journal of clinical microbiology, 46.6(2008): 2015–2021.