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Category: Bacteriology

Porphyromonas gingivalis: Periodontitis bacterium induces memory impairment and neuroinflammation

Porphyromonas gingivalis is a bacterium commonly associated in periodontitis a chronic inflammatory disease in the oral cavity.  Periodontium is composed of periodontal ligament, cementum, alveolar bone and gingiva. Porphyromonas gingivalis is a gram-negative bacterium that contains toxic components. It is characterized by the presence of edema and destruction of tissue supporting the teeth. In which periodontal bacteria enters into circulation that leads to bacteremia and system dissemination of bacterial products. Moreover, Porphyromonas gingivalis can promotes systemic effects through expression of inflammatory mediators like pro-inflammatory cytokines. As a consequence it is confirmed to be associated with systemic diseases such as diabetes, respiratory disease and cardiovascular disease.

Potential effects of Porphyromonas gingivalis

Neurodegenerative diseases have been recognized as the major cause of cognitive and behavioral damage. It is known that peripheral infections could activate microglial cells within the nervous system enhancing development of neurodegeneration. Thus, the inflammatory molecules in the brain could be enhanced by periodontitis that increase inflammatory levels promoting the development of Alzheimer’s disease. In this particular research Porphyromonas gingivalis infection may impair cognition by elevating expression of pro-inflammatory cytokines. It is also shown that the infected mice displayed impaired memory and learning abilities. Elevated levels of pro-inflammatory mediators in the blood can lead to direct or indirect transport to the brain.


Periodontal infection caused by Porphyromonas gingivalis promotes neuro-inflammatory response via releasing pro-inflammatory cytokines. In which inflammation induces alterations in neurovascular functions causing increased in blood brain barrier permeability and aggregation of toxins. In brain trauma, infection and presence of endogenic abnormal protein aggregates can activate secretions of TNF-α. That plays a pivotal role in the development and functions of central nervous system. Moreover, aging is also associated to chronic inflammation which exerts additional stress to the brain nerve cells. Additionally, during systemic inflammation the functions of the blood-cerebrospinal fluid barrier were also significantly affected.


Therefore, Porphyromonas gingivalis periodontal infection may induce age-dependent brain inflammation. Also periodontitis can cause memory impairment which has a similar effect on the development of Alzheimer’s disease. Furthermore, aging is the major risk factor of Alzheimer’s disease and is correlated with elevated glial responsiveness. And in due course might increase the brain’s susceptibility to injury and disease.


Source: Prepared by Joan Tura from BMC Immunity and Aging

Volume 15:6, January 30, 2018


Role of selenium-fortified yogurt against aflatoxin-contaminated nuts

Aflatoxins produced by a certain molds that are poisonous carcinogens which grow mostly in soil, hay, decaying plants and grains. It can affect livestock and human as natural contaminants in foods like peanuts and corn meal. There are four types of aflatoxins these are B1, B2, G1 and G2 in which all are teratogenic, carcinogenic and immunosuppressive. Its toxic effect might be due to the generation of free radicals resulting into lipid peroxidation that damage biological system. On the other hand yogurt is produced from the bacterial fermentation of milk. In which bacteria produces lactic acid that acts on milk protein to give yogurt its texture and tart flavor. However, yogurt contains plenty of probiotic bacteria that offer benefits as microflora in the intestines. It also helps boost immune response and suppress carcinogenesis since fermented dairy products contain live lactic acid bacteria.


Selenium-fortified yogurt protects against aflatoxin toxicity

Yogurt has been known as therapeutic to various disorders including lactose intolerance, indigestion, intoxication, gastroenteritis, kidney, liver disorders and cancer. Selenium added to yogurt considered as the basic trace elements vital for normal growth and development in humans and animals. It also acts as anti-oxidant as well as improves nutritional values. Additionally, selenium has both enzymatic and structural functions that protect harmful reactive oxygen and minimized the production of hydrogen peroxide from aflatoxins. Ingestion of aflatoxins leads to weight loss due to the change in digestive enzymes activity that causes malabsorption of nutrients.


Aflatoxins will impair the biosynthesis of protein which results to the degranulation of the endoplasmic reticulum. It also caused liver fibrosis and poses health risk to humans and livestock. In this research , a positive results shows that selenium-fortified yogurt suppress the level of aflatoxins in rats. It also proved that with selenium contents inhibit the activity of enzymes related to carcinogenesis. Since yogurt improves intestinal mucosa and microflora that influence intestinal barrier. These yogurt bacteria inhibit the peroxidation of lipids by foraging reactive oxygen.


Therefore, consumption of nuts infected with aflatoxins caused toxicity mainly at the kidney and liver. But intake of selenium-fortified yogurt can definitely suppress against aflatoxins toxicity. In general, application of probiotic bacteria and selenium is vital and viable therapeutic approach to improve safety in food industry. Indeed, it is recommended to eat fresh nuts to avoid aflatoxins along with selenium-fortified yogurt to lessen its toxicity.


Source: Prepared by Joan Tura from BMC Agriculture and Food Security

Volume 7:21, June 2018



Human leptospirosis cases in Palermo Italy: Rodents and Climate

Leptospirosis is a corkscrew shaped that is known as one of the most widespread bacterial zoonoses in the world. Symptoms range from mild flu to severe multi-organ failure and fatal pulmonary hemorrhagic syndrome. In which the key factors of these diseases are from stray animals, poor sanitation, rodents, heavy rainfall and flooding. Many regions have been increasingly exposed to leptospirosis infection due to climate change, global warming, poverty and high urban density. Rodents are the main animal reservoir in urban settings mainly involved in pathogenic transmission. Moreover, a high prevalence in rodent population occurs in major cities such as in Baltimore, Tokyo and Copenhagen. In Italy sporadic cases of leptospirosis have been often related to river flooding. This study focused on molecular survey of rodents in the city of Palermo, Italy.


Human leptospirosis cases

Two cases in 2009 of leptospirosis in Palermo during spring and fall seasons and there were 22 locations monitored. A rodent is the main reservoir for leptospirosis related to heavy rainfall and flooding in urban streets and riverbanks. During street floods individual were potentially in contact with water contaminated by infected rodent urine. So, the risk of infection is high but because of good hygienic conditions and economic wellness severe symptoms is rare.  It is also possible that periodic exposures to serovars leave the immune competent population more resistant to infection. Other cases also in Northern Italy an elderly woman has a fatal infection after river flooding occurs.


Based on molecular testing leptospirosis are positive in all species of wild rodents living in almost all areas in the city. Mice and rats are the natural source for this pathogenic infection. The main common problem in Palermo, Italy is the urban street floods from heavy rains and waste accumulation. In which the city is represented by almost ten thousand stray dogs feeding on garbage. Previously, a patient was in contact with contaminated water in street flood after violent cloudburst. Waste collection also is one of the problem in Palermo that eventually facilitates the increased of rodent population.


High prevalence of leptospirosis occurs in mild wet climate, flooding of urban streets and socio-economic problems. Other Italian cities has presence of simultaneous risk factors for leptospirosis, and thus, a major concern from this underestimated zoonosis should be considered by public health authorities and clinicians particularly for elderly and immune-compromised individuals. However, severe symptomatic cases are referred to hospitals and the true prevalence of infection is probably not evaluated.


Source: Prepared by Joan Tura from Journal of Infection and Public Health

Volume 11, Issue 2, March–April 2018, Pages 209-214


Isolation of Antimicrobial Producing Actinobacteria from Soil Samples

Actinobacteria is a gram-positive that mostly found in both aquatic and terrestrial environment. This kind of bacteria  reveals a great economic importance because of its contributions in agriculture and forest soil systems. Actinobacteria is much like fungi aiding in the decomposition of organic matter from the dead organisms. Because of these, the emergence of multidrug resistant bacteria made into a novel research for bioactive compound. This particular research study investigates the antimicrobial activity of Actinobacteria isolated from the soil in Egypt.

Antimicrobial Activity of Actinobacteria

One hundred samples were collected and analyzed from the farming soil of Egypt wherein 12 isolates produces activity against tested organisms. The soil sample was grown on Actinomycetes isolation agar for identification of Actinobacteria. Using ethyl acetate extraction method the culture isolates tested against indicator organisms. Such as S. aureusBacillus cereusE. coliK. pneumoniaeP. aeruginosaS. Typhi, C. albicansA. niger and A. flavus. It is then screened for their antibacterial activity on Mueller Hinton agar using streak plate technique.


The 12 isolates exhibited broad spectrum of antimicrobial activity against the test organisms. In which the zone of inhibition ranges from 2.5-10.2 mm wherein all strain of Actinobacteria could not inhibit E.coli. But the rest exhibited zone of inhibition among the test organisms. There were four isolates also showed activity to Candida albicans, two against A.niger and two against A.flavus.


Therefore, soil samples are rich in Actinobacteria that reveals a wide spectrum as an antimicrobial agent. It is also recognized as producers of various bioactive metabolites that are vital to human and medicine. These includes as an antifungal, antitumor drugs, immunomodifiers and enzymes inhibitors. On the other hand Actinobacteria also gives importance in agriculture as an insecticides, fungicides, herbicides and growth enhancement substances. Indeed, this study indicates that Actinobacteria isolated from Egypt farms could be sources of antimicrobial bioactive substances.


Sources: Prepared by Joan Tura from Saudi Journal of Biological Sciences

Volume 25, Issue 1, January 2018, Pages 44-46

Salmonella Outbreak in Minnesota

What is Salmonella?

Salmonellosis is a bacterial infection that caused by Salmonella species that normally thrives in animal and human intestines. The mode of this bacteria to shed-off is through feces. Humans usually become infected mostly due to the contaminated food or water. As well as from eating uncooked meat, eggs and poultry products. Persons with Salmonella infection typically shows symptoms like diarrhea, stomach cramps, vomiting and fever that usually develops within 8-72 hours. However, people with good immune system can recover from the infection in just few days without medication. In some cases infection of Salmonella can be life threatening and needs immediate medical attention. Severe infection will also occurs that leads to osteomyelitis, meningitis and blood stream infection.


Salmonella Outbreaks

Minnesota Departments of Health and Agriculture discover the presence of Salmonella from the sample of a dog food brand. It is found out that the outbreak is related after children became sick who might have been feed the dogs with Raw Ground Turkey Food. Two children reported sickened with Salmonella poisoning due from touching or holding the products. One of the children develops severe infection that needs proper medication and hospitalization.


The Raw for Paws Ground Turkey Food for Pets did a recall of their products manufactured last October 12, 2017. The company issued a recall notice of the products with the codes 9900008 and 9900009. A recall also from the Pet Food Combo Pack cases with the codes 99000014 and 99000015. The products were recalled last February 5, 2018 and those who purchase directly from the company were notified. However, some of the products sold online and have been resold after purchase. You can check the FDA recall notice here.


Moreover, the cages, dishes and all the things used by the dog need to be disinfected properly. Salmonella species can survive for weeks on the surface area and can be a source for a long-term infection.



5 Unexpected Activities that Release Endorphin

Endorphin is one of the natural “happy” chemicals released by our bodies. This chemical which is secreted by our brains is responsible for helping us relieves stress, anxiety, and allows us to have higher tolerance for pain. Sometimes called as the natural morphine, endorphin affects our pain and pleasure perception.