Virtual Microbes 2 Group 13 Progress by Zulia https://padlet.com/Zuliaazwa/ulgylzjnc3uw Food Pathogen en-us 2017-03-17 02:25:05 UTC 2025-11-18 21:09:12 UTC hello@padlet.com Shigella sp. Zuliaazwa https://padlet.com/Zuliaazwa/ulgylzjnc3uw/wish/160698124 2017-03-17 03:23:41 UTC https://padlet.com/Zuliaazwa/ulgylzjnc3uw/wish/160698124 First Video Meeting ! Zuliaazwa https://padlet.com/Zuliaazwa/ulgylzjnc3uw/wish/160698303 This is our first video meeting. Take a look ! :)]]> 2017-03-17 03:26:00 UTC https://padlet.com/Zuliaazwa/ulgylzjnc3uw/wish/160698303 Welcome ! Zuliaazwa https://padlet.com/Zuliaazwa/ulgylzjnc3uw/wish/160698772 2017-03-17 03:32:41 UTC https://padlet.com/Zuliaazwa/ulgylzjnc3uw/wish/160698772 Application Zuliaazwa https://padlet.com/Zuliaazwa/ulgylzjnc3uw/wish/164903641 Based on fomesafen residue toxicity in soil, the strain FB5, which can utilize fomesafen as the sole carbon source, was isolated from a fomesafen-contaminated soybean field in Heilongjiang province, China. It was found to degrade 88.32% of 500 mg/L fomesafen within 96 h. Conbined with morphological, physiological, biochemical characteristics and 16S rDNA sequence, the strain was identified as Shigella flexneri. After evaluating the effects of environmental factors such as temperature, fomesafen concentration, and primary pH, the optimum growth conditions of the strain were obtained. A remarkable remediation ability of the strain to fomesafen–polluted soils was demonstrated by a sensitive crop bioassay in pot soil. This will provide a new suitable candidate for fomesafen biodegradation and a workable pathway for solving the hazards of fomesafen residues in agricultural soils.

1.Shigella’s infection cause the proinflammatory cytokine/chemokine which is the key players in linking innate and adaptive immunity

2.Shigella cause the manipulation of innate immunity to promote its survival in the infected host drives the acquired immunity towards immunosuppressive responses.

3.Shigella species produce an alkaline slant and an acid but with no bubbles of gas in the agar in these differential media (Kligler’s Iron Agar and Triple Sugar Iron Agar). This reaction gives a presumptive identification,and slide agglutination tests with antisera for seragroup and serotype confirm the identification. 


]]> 2017-04-05 15:03:24 UTC https://padlet.com/Zuliaazwa/ulgylzjnc3uw/wish/164903641 Prevention and Treatment Zuliaazwa https://padlet.com/Zuliaazwa/ulgylzjnc3uw/wish/164903861 Prevention 
There are many steps a person can take to prevent infection with Shigella. The most important thing to do is by practicing good personal hygiene. Wash hand frequently and throughly with soap according to the correct way to wash hand before and after use toilet and before prepare food. Hand washing among children should be frequent and supervised by an adult for who have not been fully toilet trained. Besides that, tables and kitchen counters should always be wiped with antibacterial wipes before and after use. A toddler and children are more likely to get Shigella infection, the child's diaper should be sure properly dispose in closed-lid garbage can, and wash the children immediately with soap and luke water after the diaper has been changed. To prevent Shigella infection from food, always eat vegetables and fruits that have been wash and cook, and make sure to drink only boiled or treated water. Drinking bottles water is better. While travelling, Shigella infection can be prevent by follow the food and water precaution such as drink only boiled or treated water, and eat only cooked hot foods or fruits you peel yourself.

Treatment
Shigella infection can be treated by drink a lot of water to replace the fluid loss from the body and get enough rest. For serious case, antibiotic treatment and hospitalized may be required.]]> 2017-04-05 15:03:55 UTC https://padlet.com/Zuliaazwa/ulgylzjnc3uw/wish/164903861 Disease Zuliaazwa https://padlet.com/Zuliaazwa/ulgylzjnc3uw/wish/164903961 Shigellosis is a diarrheal disease caused by a group of bacteria called Shigella.Symptoms of shigellosis typically start 1–2 days after exposure and include diarrhea (sometimes bloody),fever,abdominal pain,tenesmus (a painful sensation of needing to pass stools even when bowels are empty).

Possible complications from Shigella infections include:
Hemolytic-uremic syndrome or HUS : HUS occurs when bacteria enter the digestive system and produce a toxin that destroys red blood cells. Patients with HUS often have bloody diarrhea. HUS is only associated with Shiga-toxin producing Shigella, which is found most commonly in Shigella dysenteriae.
Post-infectious arthritis : About 2% of persons who are infected with Shigella flexneri later develop pains in their joints, irritation of the eyes, and painful urination. This is called post-infectious arthritis. It can last for months or years, and can lead to chronic arthritis. Post-infectious arthritis is caused by a reaction to Shigella infection that happens only in people who are genetically predisposed to it.
Blood stream infections : Although rare, blood stream infections are caused either by Shigella organisms or by other germs in the gut that get into the bloodstream when the lining of the intestines is damaged during shigellosis. Blood stream infections are most common among patients with weakened immune systems, such as those with HIV, cancer, or severe malnutrition.
Seizures : Generalized seizures have been reported occasionally among young children with shigellosis, and usually resolve without treatment. Children who experience seizures while infected with Shigella typically have a high fever or abnormal blood electrolytes (salts), but it is not well understood why the seizures occur.


]]> 2017-04-05 15:04:09 UTC https://padlet.com/Zuliaazwa/ulgylzjnc3uw/wish/164903961 Ecology Zuliaazwa https://padlet.com/Zuliaazwa/ulgylzjnc3uw/wish/164903995 Shigella sonnei - The primary host and natural reservoir known at this point for Shigella sonnei and among all other species of Shigella is the human gastrointestinal tract. Shigella can survive in fecal contaminated material but has a low survival rate without the optimal acidic environment in the intestinal tract as its surrounding. The bacterium is known to be able to survive in soiled linen for up to seven weeks. In fresh water environments, it can live up to 5 days and in salt water for 12-30 hours. It has been recorded that Shigella sonnei can not survive on the smooth surfaces of tomatoes.

Shigella dysenteriae - Shigella dysenteriae interacts with humans, other primates, and flies. Humans act as hosts for infection, which leads to bacillary dysentery. Flies can act as means of transportation for the bacteria, spreading it to other hosts. 
Shigella dysenteriae can survive in faecally contaminated materials which can include water, foods, and other materials. It can be transmitted by person-to-person contact. It is generally transmitted with the ingestion of water and food contaminated with the bacteria. It can cause foodborne or waterborne epidemics. Water may become contaminated if someone who has Shigellosis swims in it. Crops can be contaminated with the bacteria if they are watered with contaminated water. This will cause major problems if these contaminated crops are then distributed over a large region, exposing anyone who eats the crops to infection. Epidemics are more likely in poorer countries without adequate sanitation and water treatment systems.

Shigella boydii - Shigella bacteria are found in areas of poor sanitation. Food washed with contaminated water or not cleaned properly may also be a target. In 1998 an outbreak of Shigellosis occurred in Chicago due to Shigella boydii type 18 found on the cilantro and parsley in bean salad.
Shigella is a highly infective agent able to infect a host with less than 20 cells with an onset of about 12-48 hours, in favorable conditions. Once ingested, the Shigella makes its way through the gastrointestinal tract until it reaches the epithelial cells of the intestinal mucosa, there it infects, causing irritation, inflammation and necrosis (swelling and breaking of infected cells, which spreads infection). 
Shigella species account for less than 10% of all foodborne illnesses reported in the United States. With an estimated 300,000 yearly incidents of shigellosis in the U.S., the exact percentage due to food contamination is unknown, due to the difficulty in isolating the bacteria from food but given its infectiousness the number is undoubtedly high. 

Shigella flexneri - Some strains of Escherichia coli can exert an antagonistic effect on Shigella flexneri. If Shigella flexneri is grown in the digestive tract of a germ-free mouse for 1 day before introducing Escherichia coli, Shigella flexneri disappears within 8 days. However, allowing Shigella flexneri to grow in the mice without Escherichia coli allows for the development of Shigella flexneri resistant to the antagonistic effects of Escherichia coli, but the resistance only occurred in vivo and not in vitro. The Escherichia coli-resistant population emerges without exposure to Escherichia coli, so Escherichia coli-resistance does not appear to be a selective influence in the emergence of the resistant population.
Shigella flexneri is prevalent in developing countries because sanitation is poor. The bacterium is found in the feces of infected individuals, so water polluted with feces can act as a route of infection.
]]> 2017-04-05 15:04:14 UTC https://padlet.com/Zuliaazwa/ulgylzjnc3uw/wish/164903995 Biochemical test Zuliaazwa https://padlet.com/Zuliaazwa/ulgylzjnc3uw/wish/164904615 2017-04-05 15:05:53 UTC https://padlet.com/Zuliaazwa/ulgylzjnc3uw/wish/164904615 Classification Zuliaazwa https://padlet.com/Zuliaazwa/ulgylzjnc3uw/wish/164904788 Shigella sp can classified into four different serogroups which are :
1) serogroup A : S. dysenteriae
2) serogroup B : S. flexneri
3) serogroup C : S. boydii
4)serogroup D : S. sonnei

serogroup A,B,C and D have similar physiologically but only serogroup D can be differentiate within basis biochemical metabolism assays. Each of them are Gram negative bacteria, has non spore forming and usually are non motile bacteria. This three Shigella group are the major disease cause. For example, Shigella flexneri can cause diarrhea and is he most frequently isolated species worldwide. It can treated with antibiotics. Besides, Shigella dysenteriae is usually can cause Shigellosis(bacillary dysentery). It can be spread by contaminated of water and food and also caused by unwashed hands during food preparation.

Each of the Shigella genomes includes a virulence plasmid that encodes conserved primary virulence determinants. Mostly, this shigella's chromosome share their genes with E.coli strain and some studies indicates that Shigella is more treated as subgenus of E.coli and some strain was considered E.coli.


]]> 2017-04-05 15:06:22 UTC https://padlet.com/Zuliaazwa/ulgylzjnc3uw/wish/164904788 Morphology and Taxonomy Zuliaazwa https://padlet.com/Zuliaazwa/ulgylzjnc3uw/wish/164904849 MORPHOLOGY
--> About 2-4 µm in length and 0.6µm  in breadth
--> Undergo facultative anaerobic metabolism
--> Non-spore forming and non capsulated
--> Non motile bacteria
--> Gram negative bacteria
--> Short and rod shape

TAXONOMY
Kingdom: Bacteria
Phylum: Proteobacteria
Class: Gammaproteobacteria
Order: Enterobacteriales
Family: Enterobacteriaceae
Genus: Shigella]]> 2017-04-05 15:06:31 UTC https://padlet.com/Zuliaazwa/ulgylzjnc3uw/wish/164904849 Food Associated with Shigella sp. Zuliaazwa https://padlet.com/Zuliaazwa/ulgylzjnc3uw/wish/164905533     The food which  associated with Shigella sp. are contaminated food or water, or contact with an infected person. Foods most often associated with Shigella sp. outbreaks are salads and sandwiches that involve a lot of hand contact in their preparation, and raw vegetables contaminated in the field. Besides, contamination of Salads (potato, tuna, shrimp, macaroni, and chicken), raw vegetables, milk and dairy products, and poultry  usually through the fecal-oral route.   Fecally contaminated water and unsanitary handling by food handlers are the most common causes of contamination.

    Shigella sp. can be transmitted through contaminated food and drinking water, as well as via poor hygiene (in child care centers, for example). The organisms invade the lining of the intestine, and can lead to symptoms such as diarrhea, fever, and cramps.

]]> 2017-04-05 15:08:24 UTC https://padlet.com/Zuliaazwa/ulgylzjnc3uw/wish/164905533 Reference Zuliaazwa https://padlet.com/Zuliaazwa/ulgylzjnc3uw/wish/164906301 1) Retrieved from https://www.google.com/#q=shigella
2) Elsevier L, (2011). Retrieved from http://www.sciencedirect.com/science/article/pii/S1877705811028451 ]]> 2017-04-05 15:10:28 UTC https://padlet.com/Zuliaazwa/ulgylzjnc3uw/wish/164906301