The genus Shigella exclusively infects human intestine.
Shigella dysenteriae is the causative agent of bacillary dysentery or shigellosis in humans.
It is a diarrheal illness which is characterized by frequent passage of blood stained mucopurulent stools.
The four important species of the genus Shigella are:
Shigella dysenteriae
Shigella flexneri
Shigella sonnei
Shigella boydii.
Microbiology of E coli giving basic of Escherichia coli, its morphology, cultural and biochemical characteristics, Antigenic character, pathogenesis, laboratory diagnosis, prevention and control
The genus Shigella exclusively infects human intestine.
Shigella dysenteriae is the causative agent of bacillary dysentery or shigellosis in humans.
It is a diarrheal illness which is characterized by frequent passage of blood stained mucopurulent stools.
The four important species of the genus Shigella are:
Shigella dysenteriae
Shigella flexneri
Shigella sonnei
Shigella boydii.
Microbiology of E coli giving basic of Escherichia coli, its morphology, cultural and biochemical characteristics, Antigenic character, pathogenesis, laboratory diagnosis, prevention and control
pseudomonas aeruginosa is one of the leading cause of hospital-associated infection. mainly Pseudomonas is a multi drug resistant bacteria.
they are oxidase positive, non fermenters, strictly aerobic bacteria.
they are pigment producing, pigment can be appreciated on nutrient agar.
General discription about E coli.. Classification scheme of E coli. Pathogenecity of E coli. Pathological characters of E coli. slide contains animations and may not support in mobile.. Use laptop for full view
pseudomonas aeruginosa is one of the leading cause of hospital-associated infection. mainly Pseudomonas is a multi drug resistant bacteria.
they are oxidase positive, non fermenters, strictly aerobic bacteria.
they are pigment producing, pigment can be appreciated on nutrient agar.
General discription about E coli.. Classification scheme of E coli. Pathogenecity of E coli. Pathological characters of E coli. slide contains animations and may not support in mobile.. Use laptop for full view
Bacillary dysentery is a gastrointestinal disease. Bacillary means related to bacteria, and dysentery is severe diarrhea containing blood or mucus. With bacillary dysentery, a bacterial infection becomes more invasive and severe, causing inflammation in the intestines. Symptoms can range from mild to life-threateningDysentery is an infection of the intestines that causes diarrhoea containing blood or mucus. Other symptoms of dysentery can include: painful stomach cramps. feeling sick or being sick (vomiting)Transmission is fecal-oral and is remarkable for the small number of organisms that may cause disease (10 ingested organisms cause illness in 10% of volunteers, and 500 organisms cause disease in 50% of volunteers). Shigella bacteria invade the intestinal mucosal cells but do not usually go beyond the lamina propria. Dysentery is caused when the bacteria escape the epithelial cell phagolysosome, multiply within the cytoplasm, and destroy host cells. Shiga toxin causes hemorrhagic colitis and hemolytic-uremic syndrome by damaging endothelial cells in the microvasculature of the colon and the glomeruli, respectively. In addition, chronic arthritis secondary to S. flexneri infection, called reactive arthritis, may be caused by a bacterial antigen; the occurrence of this syndrome is strongly linked to HLA-B27 genotype, but the immunologic basis of this reaction is not understoodSpecimen: Fresh stool is collected.
Culture: Specimen is inoculated on selective media like MacConkey's agar, DCA, XLD agar. Selenite F broth(0.4%) is used as enrichment medium which permits the rapid growth of enteric pathogens while inhibiting the growth of normal flora like E. coli for 6–8 hours. Subculture is done on the solid media from selenite F broth. All the solid media are incubated at 37 degrees for 24 hours.
Cultural characteristics: Colorless (NLF) colonies appear on MacConkey's agar which are further confirmed by gram staining, hanging drop preparation and biochemical reactions.Dysentery is initially managed by maintaining fluid intake using oral rehydration therapy. If this treatment cannot be adequately maintained due to vomiting or the profuseness of diarrhea, hospital admission may be required for intravenous fluid replacement. Ideally, no antimicrobial therapy should be administered until microbiological microscopy and culture studies have established the specific infection involved. When laboratory services are not available, it may be necessary to administer a combination of drugs, including an amoebicidal drug to kill the parasite and an antibiotic to treat any associated bacterial infection.
Anyone with bloody diarrhea needs immediate medical help. Treatment often starts with an oral rehydrating solution—water mixed with salt and carbohydrates—to prevent dehydration. (Emergency relief services often distribute inexpensive packets of sugars and mineral salts that can be mixed with clean water and used to restore lifesaving fluids in dehydrated child
Basic discussion on Clinical and Microbiological Aspects of Food Poisoning caused by various bacteria, viruses, protozoa, and Fungi along with their clinical and laboratory diagnosis and basic management.
1- Understand the pathophysiologic mechanisms involved in chronic diarrhea.
2. Classification the causes of chronic diarrhea in resource-rich and resource-limited countries
3- Know how to evaluate a child who has chronic diarrhea
4. Know the therapies for the many causes of chronic diarrhea
Acetabularia Information For Class 9 .docxvaibhavrinwa19
Acetabularia acetabulum is a single-celled green alga that in its vegetative state is morphologically differentiated into a basal rhizoid and an axially elongated stalk, which bears whorls of branching hairs. The single diploid nucleus resides in the rhizoid.
Model Attribute Check Company Auto PropertyCeline George
In Odoo, the multi-company feature allows you to manage multiple companies within a single Odoo database instance. Each company can have its own configurations while still sharing common resources such as products, customers, and suppliers.
Read| The latest issue of The Challenger is here! We are thrilled to announce that our school paper has qualified for the NATIONAL SCHOOLS PRESS CONFERENCE (NSPC) 2024. Thank you for your unwavering support and trust. Dive into the stories that made us stand out!
The French Revolution, which began in 1789, was a period of radical social and political upheaval in France. It marked the decline of absolute monarchies, the rise of secular and democratic republics, and the eventual rise of Napoleon Bonaparte. This revolutionary period is crucial in understanding the transition from feudalism to modernity in Europe.
For more information, visit-www.vavaclasses.com
Embracing GenAI - A Strategic ImperativePeter Windle
Artificial Intelligence (AI) technologies such as Generative AI, Image Generators and Large Language Models have had a dramatic impact on teaching, learning and assessment over the past 18 months. The most immediate threat AI posed was to Academic Integrity with Higher Education Institutes (HEIs) focusing their efforts on combating the use of GenAI in assessment. Guidelines were developed for staff and students, policies put in place too. Innovative educators have forged paths in the use of Generative AI for teaching, learning and assessments leading to pockets of transformation springing up across HEIs, often with little or no top-down guidance, support or direction.
This Gasta posits a strategic approach to integrating AI into HEIs to prepare staff, students and the curriculum for an evolving world and workplace. We will highlight the advantages of working with these technologies beyond the realm of teaching, learning and assessment by considering prompt engineering skills, industry impact, curriculum changes, and the need for staff upskilling. In contrast, not engaging strategically with Generative AI poses risks, including falling behind peers, missed opportunities and failing to ensure our graduates remain employable. The rapid evolution of AI technologies necessitates a proactive and strategic approach if we are to remain relevant.
Honest Reviews of Tim Han LMA Course Program.pptxtimhan337
Personal development courses are widely available today, with each one promising life-changing outcomes. Tim Han’s Life Mastery Achievers (LMA) Course has drawn a lot of interest. In addition to offering my frank assessment of Success Insider’s LMA Course, this piece examines the course’s effects via a variety of Tim Han LMA course reviews and Success Insider comments.
Instructions for Submissions thorugh G- Classroom.pptxJheel Barad
This presentation provides a briefing on how to upload submissions and documents in Google Classroom. It was prepared as part of an orientation for new Sainik School in-service teacher trainees. As a training officer, my goal is to ensure that you are comfortable and proficient with this essential tool for managing assignments and fostering student engagement.
2. Coliform bacilli (enteric rods)
Nonmotile gram-negative facultative anaerobes
Four species
•Shigella sonnei (most common in industrial world)
•Shigella flexneri (most common in developing
countries)
•Shigella boydii
•Shigella dysenteriae
Non-lactose fermenting
Resistant to bile salts
General Characteristics of ShigellaGeneral Characteristics of Shigella
3. Shigellosis = Generic term for disease
Low infectious dose (102
-104
CFU)
Humans are only reservoir
Transmission by fecal-oral route
Incubation period = 1-3 days
Watery diarrhea with fever; changing to dysentery
Major cause of bacillary dysentery (severe 2nd
stage)
in pediatric age group (1-10 yrs) via fecal-oral route
Outbreaks in daycare centers, nurseries, institutions
Estimated 15% of pediatric diarrhea in U.S.
Leading cause of infant diarrhea and mortality
(death) in developing countries
Epidemiology and ClinicalEpidemiology and Clinical
Syndromes of ShigellaSyndromes of Shigella
4. DEFINITIONS
Enterotoxin = an exotoxin with enteric activity, i.e.,
affects the intestinal tract
Dysentery = inflammation of intestines (especially
the colon (colitis) of the large intestine) with
accompanying severe abdominal cramps,
tenesmus (straining to defecate), and frequent, low-
volume stools containing blood, mucus, and
fecal leukocytes (PMN’s)
Bacillary dysentery = dysentery caused by
bacterial infection with invasion of host cells/tissues
and/or production of exotoxins
6. Shigellosis
Two-stage disease:
Early stage:
• Watery diarrhea attributed to the enterotoxic
activity of Shiga toxin following ingestion and
noninvasive colonization, multiplication, and
production of enterotoxin in the small intestine
• Fever attributed to neurotoxic activity of toxin
Second stage:
• Adherence to and tissue invasion of large
intestine with typical symptoms of dysentery
• Cytotoxic activity of Shiga toxin increases
severity
Pathogenesis of ShigellaPathogenesis of Shigella
7. Pathogenesis and Virulence FactorsPathogenesis and Virulence Factors
Virulence attributable to:
Invasiveness
• Attachment (adherence) and internalization
with complex genetic control
• Large multi-gene virulence plasmid regulated by
multiple chromosomal genes
Exotoxin (Shiga toxin)
Intracellular survival & multiplication
8. Penetrate through mucosal surface of colon
(colonic mucosa) and invade and multiply in the
colonic epithelium but do not typically invade
beyond the epithelium into the lamina propria (thin
layer of fibrous connective tissue immediately beneath the
surface epithelium of mucous membranes)
Preferentially attach to and invade into M cells in
Peyer’s patches (lymphoid tissue, i.e., lymphatic system)
of small intestine
Invasiveness in Shigella-Associated Dysentery
Pathogenesis and Virulence FactorsPathogenesis and Virulence Factors
9. M cells typically transport foreign antigens from
the intestine to underlying macrophages, but
Shigella can lyse the phagocytic vacuole
(phagosome) and replicate in the cytoplasm
• Note: This contrasts with Salmonella which
multiplies in the phagocytic vacuole
Actin filaments propel the bacteria through the
cytoplasm and into adjacent epithelial cells with
cell-to-cell passage, thereby effectively avoiding
antibody-mediated humoral immunity (similar
to Listeria monocytogenes)
Pathogenesis and Virulence FactorsPathogenesis and Virulence Factors
Invasiveness in Shigella-Associated Dysentery(cont.)
10.
11. Methods That CircumventMethods That Circumvent
Phagocytic KillingPhagocytic Killing
See Chpt. 19
, Shigella spp.
Shigella spp.
,
12. Enterotoxic, neurotoxic and cytotoxic
Encoded by chromosomal genes
Two domain (A-5B) structure
Similar to the Shiga-like toxin of
enterohemorrhagic E. coli (EHEC)
• NOTE: except that Shiga-like toxin is encoded by
lysogenic bacteriophage
Pathogenesis and Virulence FactorsPathogenesis and Virulence Factors
Characteristics of Shiga Toxin
13. Shiga Toxin Effects in Shigellosis
Enterotoxic Effect:
Adheres to small intestine receptors
Blocks absorption (uptake) of electrolytes,
glucose, and amino acids from the intestinal
lumen
• Note: This contrasts with the effects of cholera toxin
(Vibrio cholerae) and labile toxin (LT) of
enterotoxigenic E. coli (ETEC) which act by blocking
absorption of Na+
, but also cause hypersecretion
of water and ions of Cl-
, K+
(low potassium =
hypokalemia), and HCO3
-
(loss of bicarbonate
buffering capacity leads to metabolic acidosis) out of
the intestine and into the lumen
Pathogenesis and Virulence FactorsPathogenesis and Virulence Factors
14. Cytotoxic Effect:
B subunit of Shiga toxin binds host cell glycolipid
A domain is internalized via receptor-mediated
endocytosis (coated pits)
Causes irreversible inactivation of the 60S
ribosomal subunit, thereby causing:
• Inhibition of protein synthesis
• Cell death
• Microvasculature damage to the intestine
• Hemorrhage (blood & fecal leukocytes in
stool)
Neurotoxic Effect: Fever, abdominal cramping are
Shiga Toxin Effects in Shigellosis (cont.)
Pathogenesis and Virulence FactorsPathogenesis and Virulence Factors
16. Lab diagnosticLab diagnostic
• Specimens: fecal leucocytes and rbc seen
microscopically
• Culture: material streaked on differential
selective media
• Serology: not used to dianose shigella
infection
Culture medium
17. ImmunityImmunity
• Infection followed by antibody response
• Injection of kiled shigella stimulate the
production ofnantibodies in serum, but fails to
protect human body against infection
• Ig Aantibody in gut in important
• Serum antibody to somatic shigella antigens
are Ig M
18. ControlControl
• Sanitary control of water, food and milk;
sewage disposal; and fly control
• Isolation of patient and disinfection of excreta
• Detection of sub clinical cases and carrier,
particularly food handlers; and;
• Antibiotic treatment of infected individuals