Salmonella is a gram-negative rod-shaped bacteria from the Enterobacteriaceae family. It is classified into two species, Salmonella enterica and Salmonella bongori, with over 2,500 serotypes identified. Salmonella can cause enteric (typhoid) fever through fecal-oral transmission, or gastroenteritis through contaminated food or water. Clinical manifestations depend on the infecting serotype and host factors. Laboratory diagnosis involves culture of blood, bone marrow, or stool to isolate the bacteria. Treatment focuses on hydration and antibiotics such as fluoroquinolones.
Microbiology of E coli giving basic of Escherichia coli, its morphology, cultural and biochemical characteristics, Antigenic character, pathogenesis, laboratory diagnosis, prevention and control
Haemophilus is the name of a group of bacteria. There are several types of Haemophilus. They can cause different types of illnesses involving breathing, bones and joints, and the nervous system. One common type, Hib (Haemophilus influenzae type b), causes serious disease. It usually strikes children under 5 years old
Clostridium are anerobic gram positive rod shaped spore forming organisms responsible to cause various life threatening diseases in humans like Gas gangrene, Tetanus, Botulism, etc
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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.
Microbiology of E coli giving basic of Escherichia coli, its morphology, cultural and biochemical characteristics, Antigenic character, pathogenesis, laboratory diagnosis, prevention and control
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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.
Gastrointestinal pathogens of the family Vibrionaceae: Include the following medically important genera: Vibio cholerae, Aeromonas, Campylobacter, and Helicobacter pylori.
Biological screening of herbal drugs: Introduction and Need for
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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.
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Instructions for Submissions thorugh G- Classroom.pptxJheel Barad
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Synthetic Fiber Construction in lab .pptxPavel ( NSTU)
Synthetic fiber production is a fascinating and complex field that blends chemistry, engineering, and environmental science. By understanding these aspects, students can gain a comprehensive view of synthetic fiber production, its impact on society and the environment, and the potential for future innovations. Synthetic fibers play a crucial role in modern society, impacting various aspects of daily life, industry, and the environment. ynthetic fibers are integral to modern life, offering a range of benefits from cost-effectiveness and versatility to innovative applications and performance characteristics. While they pose environmental challenges, ongoing research and development aim to create more sustainable and eco-friendly alternatives. Understanding the importance of synthetic fibers helps in appreciating their role in the economy, industry, and daily life, while also emphasizing the need for sustainable practices and innovation.
June 3, 2024 Anti-Semitism Letter Sent to MIT President Kornbluth and MIT Cor...Levi Shapiro
Letter from the Congress of the United States regarding Anti-Semitism sent June 3rd to MIT President Sally Kornbluth, MIT Corp Chair, Mark Gorenberg
Dear Dr. Kornbluth and Mr. Gorenberg,
The US House of Representatives is deeply concerned by ongoing and pervasive acts of antisemitic
harassment and intimidation at the Massachusetts Institute of Technology (MIT). Failing to act decisively to ensure a safe learning environment for all students would be a grave dereliction of your responsibilities as President of MIT and Chair of the MIT Corporation.
This Congress will not stand idly by and allow an environment hostile to Jewish students to persist. The House believes that your institution is in violation of Title VI of the Civil Rights Act, and the inability or
unwillingness to rectify this violation through action requires accountability.
Postsecondary education is a unique opportunity for students to learn and have their ideas and beliefs challenged. However, universities receiving hundreds of millions of federal funds annually have denied
students that opportunity and have been hijacked to become venues for the promotion of terrorism, antisemitic harassment and intimidation, unlawful encampments, and in some cases, assaults and riots.
The House of Representatives will not countenance the use of federal funds to indoctrinate students into hateful, antisemitic, anti-American supporters of terrorism. Investigations into campus antisemitism by the Committee on Education and the Workforce and the Committee on Ways and Means have been expanded into a Congress-wide probe across all relevant jurisdictions to address this national crisis. The undersigned Committees will conduct oversight into the use of federal funds at MIT and its learning environment under authorities granted to each Committee.
• The Committee on Education and the Workforce has been investigating your institution since December 7, 2023. The Committee has broad jurisdiction over postsecondary education, including its compliance with Title VI of the Civil Rights Act, campus safety concerns over disruptions to the learning environment, and the awarding of federal student aid under the Higher Education Act.
• The Committee on Oversight and Accountability is investigating the sources of funding and other support flowing to groups espousing pro-Hamas propaganda and engaged in antisemitic harassment and intimidation of students. The Committee on Oversight and Accountability is the principal oversight committee of the US House of Representatives and has broad authority to investigate “any matter” at “any time” under House Rule X.
• The Committee on Ways and Means has been investigating several universities since November 15, 2023, when the Committee held a hearing entitled From Ivory Towers to Dark Corners: Investigating the Nexus Between Antisemitism, Tax-Exempt Universities, and Terror Financing. The Committee followed the hearing with letters to those institutions on January 10, 202
2. Family: Enterobacteriaceae
Gram-negative rods
Motile except Salmonella Gallinarum and S. Pullorum
Aerobic and facultatively anaerobic
Catalase positive; oxidase negative
Attack sugars by fermentation and produces gas
Citrate utilization usually positive except S. Typhi and S.
Paratyphi A
Lysine decarboxylase usually positive except S.
Paratyphi A
G+C content 50-53 mol%
4. Cultural character
Grow on ordinary culture media
In MacConkey agar and DCA: Small, circular,
translucent, nonlactose fermenting colonies.
In Wilson and Blair Bismuth sulfite medium: Black
colonies with metallic sheen due to production of
H2S
Selenite F and tetrathionate broth (enrichment
media for stool specimen culture)
5. Biochemical reaction
Do not ferment lactose or sucrose
Do not produce indole
Ferment glucose, mannitol, maltose with
production of acid and gas except S. Typhi
(produces acid only)
Most strain produces H2S in TSI agar except S.
Paratyphi A and S. Choleraesuis
Methyl red positive
6. Classification
Based on DNA-DNA hybridization: 2 species
a. Salmonella enterica and
b. Salmonella bongori
Salmonella enterica comprises 6 sub species
S. enterica subspecies enterica
subspecies salamae
subspecies arizonae
subspecies diarizonae
subspecies houtanae
subspecies indica
7. Popoff, et. al.
2541 serotypes
Sub spp enterica 1504
Sub spp salamae 502
Sub spp arizonae 95
Sub spp diarizonae 333
Sub spp houtanae 72
Sub spp indica 13
S. bongori 22
8. Biochemical reaction patterns of S.
Typhi and S. Paratyphi (d=delayed)
S.
Typhi
S. Paratyphi
A
S. Paratyphi
B
S. Paratyphi C
Glucose A AG AG AG
Xylose d - AG AG
D-
tartrate
A - - AG
Mucate d - AG -
9. Biochemical reactions of some Salmonella serotypes of
subsp. enterica (subsp,I)
Reaction Most serotypes Typhi Paratyphi-A Choleraesuis Gallinarum Pullorum
Gas from sugar + - + + - +
Citrate utilization + - - d + -
H2S + w - - - -
Lysine decarboxylase + + - + + +
Ornithine decarboxylase+ - + + - +
Motility + + + + - -
10. Antigenic structure
3 types
a. O antigen (Somatic)
b. H antigen (Flagellar): present in either or both of two forms- phase 1 and
phase 2.
c. Vi antigen (capsular) includes
F antigen (fimbrial)
M antigen
R antigen
Vi antigen is also found in other bacteria than S. Typhi eg
S. Paratyphi C, S. Dublin
Some strains of E. coli and Citrobacter
11. Antigenic variation
a. H O variation:
Lose flagella and becomes non-motile.
When cultivated in hard agar (phenol 1:800)
b. Phase variation
Occurs in one of two phase i.e. phase 1 or phase 2.
Phase 1 is more specific and is shared by few species.
Phase 2 is non-specific or group phase.
Phase 2 is shared by several unrelated species of
Salmonellae.
12. Antigenic variation contd……
c. S R variation: Smooth to rough variation
It is due to
Change of colonial morphology from smooth to rough
Loss of O antigen and
Loss of virulence
It can be avoided by
Maintaining culture in Dorset’s egg medium or by lyophilization
d. V W variation:
Vi antigen completely mask the O antigen and render O antisera
inagglutinable.
These are agglutinable with Vi antisera
Can be removed by boiling or
By repeated subcultivation in the laboratory media
13. Kauffman and White scheme of classification
Antigenic notation: consists of 3 parts
a. O antigen: In arabic numerals
b. Phase-1 H antigen: a to z and then z1 to z83
c. Phase-2 H antigen: arabic numerals 1-12
O-ag serogroup Serotype O antigens H antigen
Phase-1 Phase- 2
2 A S. Paratyphi A 1,2,12 a [1,5]
4 B S. Paratyphi B 1,4,[5],12 b 1,2
7 C1 S. Paratyphi C 6,7[vi] c 1,5
9 D S. Typhi 9,12[vi] d -
14. Virulence factors
Endotoxin- LPS of cell wall
Invasins - mediates adherence to and penetration of
intestinal epithelial cells.
Resistance to phagocytosis
Vi antigen – antiphagocytic property
Resistance to acid pH – acid tolerance response gene
(ATR gene)
Quorum sensing
15. Cardinal feature of Salmonella
Ability to withstand phagocytosis
(intracellular multiplication)
Produces endotoxin
Resistance to bile
17. Salmonellae causes the following clinical
syndrome in human beings
1. Enteric fever
2. Septicaemia with or without local
suppurative lesion
3. Gastroenteritis or food poisoning
18. Enteric fever
Typhoid fever caused by S. Typhi and paratyphoid fever
caused by S. Paratyphi A,B and C.
The name typhoid was given by Louis (1829) who
distinguish it from typhus fever.
In 1869, based on anatomical site of infection, the term
enteric fever was proposed.
It is systemic disease characterized by fever and abdominal
pain.
19. Enteric fever contd…,
Epidemiology
Disease of underdeveloped and developing countries (global health
problem)
13-17 million case/year
600,000 deaths/year
Transmission: close contact with acutely infected individuals or chronic
carriers
Faeco-oral rare
Most cases via contaminated food and water
20. Epidemiology contd….
Antibiotic resistant among salmonellae is a rising concern
and has been linked to antibiotic use in live stock.
Ciprofloxacin resistance either plasmid or chromosomally
mediated has been observed.
ESBL producing strains have been reported from different
part of world including Nepal.
Food handlers and cooks who become carriers are
particularly dangerous
Mary Mallon (‘Typhoid Mary’) - a New York cook - over a 15
years- at least 7 outbreaks affecting over 200 individuals.
21. Clinical course
Incubation period: 3-21 days
Fever: > 75% and abdominal pain: 20-40% at presentation.
Most prominent symptom: prolonged fever(101.8o
c-104.9o
c)
Chills, headache, weakness, dizziness and muscle pain.
GI symptoms are quite variable (Diarrhea or constipation).
Early physical findings: rose spots in the trunk and chest
region, hepatosplenomegaly and relative bradycardia.
Late complication (untreated adults): Intestinal perforation
and/or gastrointestinal hemorrhage
Rare complication: pancreatitis, hepatic and splenic
abscess, endocarditis, pericarditis, orchitis, hepatitis,
meningitis, nephritis, myocarditis, pneumonia, arthritis,
osteomylitis, and parotitis.
Approx 1-5% of the patients become asymptomatic
22. Laboratory diagnosis
Four principles
1. Isolation of bacteria from blood
2. Demonstration of antibody
3. Demonstration of circulating antigen
4. General blood picture
The choice of specimen depends upon stage
of the disease
25. Lab.diagnosis contd…
Blood culture
Blood: Broth ratio- 1:10
Larger volume of media helps to dilute the
antibacterial substance present in the blood.
Incubation up to 7 days at 370
c.
Sub culture 1st
after 24 hours and then after
every 48 hours or if culture appears turbid.
26. Bone marrow culture
More sensitive(abt.90%) than blood
culture.
Even after starting antibacterial
therapy(<5days) it remains positive.
27. Urine/Stool culture
Positive during 3rd
and 4th
week of illness.
If blood, bone marrow and intestinal
secretions are all cultured, the yield of
a positive culture is >90%.
28. Bactec system
Monitors bacterial growth by detecting 14
C-
labelled CO2 produced by bacterial
metabolism of 14
C-labelled substrate in the
liquid growth medium.
29. Widal test
Detects O and H agglutinins for typhoid and
paratyphoid bacilli.
Two types of tubes are used
Dreyer’s tube for H agglutination: narrow tube with
conical bottom
Felix tube for O agglutination: short round bottomed
tube
H agglutination: loose, cottony agglutinates
O agglutination: compact granular agglutinates.
30. Antigen preparation for widal test
H-antigen
Organisms are cultured in liquid media
(Hazana broth)- overnight
Preserved by adding 0.1% formalin
32. General blood picture
In 15-25% of cases, leukopenia and
neutropenia.
In majority of cases WBC normal despite
high fever
Leukocytosis in children during the 1st
10
days or in the complicated case like
intestinal perforation.
33. Carrier detection
This is important for epidemiological and
public health purpose
For detection
Bile or duodenal aspiration culture
Stool and urine culture
Vi antigen detection
34. Serotyping
Growth on agar slope is used for
agglutination
a. Polyvalent O ( Groups A-G)
b. Group specific sera
c. H-antisera
d. Polyvalent-H, specific and non-specific
e. Vi antiserum
35. Antibiotic sensitivity
Many strains are sensitive to chloramphenicol,
Ampicillin, Tetracycline and Cotrimoxazole.
However, resistance to individual drugs
depends on serotype, phagetype and country
of origin.
Chloramphenicol was considered to be the
drug of choice
36. Antibiotic sensitivity contd…
Ciprofloxacin is considered as a 1st
line
choice for treatment of typhoid fever.
In case of Nalidixic acid resistant (NAR)
strain, ciprofloxacin should be given in
higher in dose for longer period or third
generation cephalosporin should be
administered.
37. Gastroenteritis
Common serotypes S. Enteriditis and S.Typhimurium
Symptoms appear within 48 hours of ingesting
contaminated food and water.
Characterized by nausea, vomiting and diarrhea usu.
non-bloody.
Fever and abdominal cramps are common.
Self limiting within 48-72 hours and doesn’t require
treatment except in children and debilitated adults.
For unknown reasons, it is found in persons who carry
HLA-B 27 histocompatibility marker.
44. Immunisation
Several vaccines are in use
1. Killed S. Typhi vaccine
TAB vaccine containing S. Typhi, S. Paratyphi A and B
2. Live oral vaccine (Ty 21a)
Oral administration of avirulent mutant strain of S. Typhi, Gal E
mutant lacking UDP-galactose-4-epimerase
Mutant initiate infection in the intestine but self-destructs after
4-5 cell divisions and can’t produce any illness.
Three doses on alternate days to children.
3.Purified Vi polysaccharide vaccine( typhim-Vi)
Single dose
Intramuscularly