BACILLARY DYSENTRY
SHIGELLA SPECIES
Dr.Indumathi
KLEBSIELLA
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GRAM NEGATIVE
NON MOTILE
CAPSULATED
LACTOSE FERMENTING(MUCOID)
IMViC --++
• FORMS GUT AND RESPIRATORY
FLORA IN 5% NORMAL INDIVIDUALS
CLASSIFICATION
• 3 SPECIES”
• K.pneumonia ; K.rhinoscleromatis and
K.ozanae
• PATHOGENIC LESIONS:
• HAEMORRHAGIC NECROTIZING
CONSOLIDATION OF LUNG (1%) :
• UTI
• BACTEREMIA & OTHER FOCAL INFECTION
• NOSOCOMIAL INFECTION
PNEUMONIA
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FRIEDLANDER’S PNEUMONIA : CAP
MIDDLE AGED AND OLD ALCOHOLICS
SEVERE RAPID ONSET
OFTEN FATAL
HIGH FEVER, CHILLS, CURRENT JELLY
SPUTUM
• ABSCESS, CAVITATION, EMPYEMA
• LOBAR PNEUMONIA WITH DESTRUCTIVE
CHANGES : USUALLY UPPER LOBE
KLEBSIELLA PNEUMONIA
RHINOSCLEROMA
• K.RHINOSCLEROMATIS
• AFRICA, ASIA, LATIN AMERICA
• DESTRUCTIVE GRANULOMA OF NOSE AND
PHARYNX
• PURULENT NASAL DISCHARGE
• CRUSTING LESIONS WITH NODULE
• RESPIRATORY OBSTRUCTION
• DIAGNOSIS BY HPE AND POSITIVE BLOOD
CULTURE
RHINOSCLEROMA
OZENA
• K.OZAENAE
• FETID PROGRESSIVE ATROPHY OF
NASAL MUCOSA
• NASAL CONGESTION
• PRIMARY ATROPHIC RHINITIS IN
ELDERLY
• NASAL BAD SMELL
• HEADACHE
HISTORICAL REVIEW
• TERM DYSENTRY: BY HIPPOCRATES
• FREQUENT PASSAGE OF STOOL WITH
BLOOD AND MUCOUS
• STRAINING AND PAINFUL DEFECATION
• 19TH CENTRURY : 2 FORMS OF DYSENTRY
ACCURATELY SEPARATED
• EPIDEMICS DYSENTRY IN MILITARY CAMPS,
ASYLUMS, JAILS BY SHIGELLA
• SPORADIC CASES OF DYSENTRY BY
AMEOBA
SHIGELLA
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GRAM NEGATIVE SHORT RODS
NON MOTILE
ANAEROGENIC
NON CAPSULATED
GIT PATHOGEN
NON LACTOSE FERMENTER
COMPLEX ANTIGENIC STRUCTURE
NAMED AFTER SHIGA 1896
CLASSIFICATION
• 4 SPECIES/SUBGROUPS BASED ON
BIOCHEMICAL AND SEROLOGICAL
CHARACTERS
• SHIGELLA DYSENTERIAE : 12 Serotypes
• SHIGELLA FLEXNERI : 6 serotypes
• SHIGELLA BOYDII : 18
• SHIGELLA SONNEI : 17 Colicine types
EPIDEMIOLOGY : BACILLARY
DYSENTRY
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PREVALENT IN TROPICS/WORLD WIDE
SUMMER MONTHS
POOR SANITATION
OVERCROWDING /POVERTY
EPIDEMICS
MAN IS THE ONLY HOST :
CASE/CARRIER :RESERVOIR
• SHORT INCUBATION (48 HRS)
EPIDEMIOLOGY
• CYCLIC PATTERN OF DISEASE
• EPIDEMICS DUE TO ONE SPECIES
LASTING FOR 20-30YRS.
• E.G. 20TH CENTURY : S.DYSENTERIAE
IN EUROPE
• 1926-38 S.FLEXNERI
• CURRENTLY S.SONNEI : IN
INDUSTRIALISED COUNTRIES
EPIDEMIOLOGY
INDIA
• ENDEMIC /HIGHLY COMMUNICABLE
• FOUND IN ALL AGE GROUPS
• ALL SPECIES : S.FLEXNERI
PREDOMINANT(50-85%)
• S.DYSENTERIAE(8-25%)
• S.SONNEI (2-24%)
• S.BOYDII(0-8%)
• EPIDEMICS AND SERVERAL OUTBREAKS
FROM 1974 : KERALA AND WEST BENGAL
• MULTIPLE DRUG RESISTANT STRAINS :
CAUSING EPIDEMICS
PATHOGENESIS
• SOURCE : MAN: CASE OR CARRIER
• MODE OF SPREAD: CONTAMINATED
FINGERS, FOOD, FLIES, FOMITES
• PERSON TO PERSON TRANSMISSION
• INFECTIVE DOSE: 10-100 VIABLE BACILLI
• HIGHEST CONCENTRATION IN STOOL
DURING EARLY/ACUTE INFECTION 103 TO
109 VIABLE BACILLI PER GRAM OF STOOL
• POST CONVALESCENT SHEDDING : LOW
COUNTS 102 TO 103
PATHOGENESIS
• VIRULENCE FACTORS
• 1.INVASIVENESS : ASSOCIATED WITH
BACTERIAL PROTEIN CODED IN
PLASMIDS OR CHROMOSOME.
• 2. TOXIN PRODUCTION : EXOTOXIN
THAT IS ENTERO,NEURO AND
CYTOTOXIC : SHIGA TOXIN
PATHOGENESIS
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INGESTED BACILLI
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TRANSIENTLY MULTIPLY IN SMALL INTESTINE
CONCENTRATION OF 107 TO109 PER ML
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ENTER THE DISTAL COLON (MULTIPLY) INVADE THE MUCOSAL
CELLS,
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MULTIPLY AND SPREAD TO ADJECENT CELLS(INTRACELLULAR
SPREAD)
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ACUTE INFLAMMATION AND MICROABSCESS/CAP THROMOBOSIS
SUPERFICIAL ULCERATION (SERPIGINOUS)
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ENDOTOXIN PRODUCTION TO PRODUCE BOWEL IRRITATION AND
DIARRHOEA WITH BLOOD/MUCUS AND TOXEMIA
PATHOGENESIS
• NO BLOOD STREAM INVASION
• BACTERIA RAPIDLY PHAGOCYTOSED BY
MACROPHAGES
• ENTEROTOXIN : LOCAL MUCOSAL DESTRUCTION
• CLINICALLY : DYSENTRY LASTS FOR 1 TO 7 DAYS
SELF LIMITING
• HIGH MORTALITY IN MALNOURISHED
• COMPLICATIONS :HEMOLYTIC UREMIC SYNDROME
: SHIGA TOXIN : RENAL FAILURE, TOXIC NEURITIS,
ARTHRITIS
• RARELY : IKARI SYNDROME : MASSIVE INFECTION
AND EARLY DEATH IN CHILDREN
CLINICAL FEATURES
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FEVER : HIGH GRADE
TOXEMIA
ABDOMINAL CRAMPS
VOLUMINOUS WATERY DIARRHOEA
FOLLOWED BY SMALL VOLUME FREQUENT
PASSAGE OF BLOODY STOOLS.
(OVER 10/DAY)
• ABDOMINAL TENDERNESS
• COMPLICATIONS: FEBRILE SEIZURES,
SEPSIS, PNEUMONIA
LAB DIAGNOSIS
SPECIMEN COLLECTION :
STOOL CONTAINING MUCOUS/BLOOD
RECTAL SWAB
RECTAL CATHETERIZATION
RECOVERY IS BEST IN THE ACUTE
STAGE WHERE BACILLI ARE SHED IN
LARGE NUMBERS
LAB DIAGNOSIS
• TRANSPORT MEDIUM
• BGS/CARY BLAIR
• ENRICHMENT : SELENITE F
METHODS OF DIAGNOSIS
DIRECT MICROSCOPY
CULTURE
SLIDE AGGLUTINATION TEST
LAB DIAGNOSIS
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• MACROSCOPY
BRIGHT RED STOOL
ADHERENT TO CONTAINER
ALKALINE
ODOURLESS
NO FAECAL MATTER
SMALL QUANTITY :
LAB DIAGNOSIS
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MICROSCOPY
• NUMEROUS PUS CELLS : STAINED FEACAL
SMEARS WITH METHYLENE BLUE (SINGLE
MOST IMPORTANT LAB TEST OTHER THAN
STOOL CULTURE)
• NUMEROUS DISCRETE/ROULEUX RBCS
• NO BACTERIA SEEN
• PLENTY OF MACROPHAGES
• GHOST CELLS : CELLS WITH NO NUCLEUS
AND ONLY CYTOPLASMIC OUTLINE :
PRESENT
LAB DIAGNOSIS
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CULTURE : MEDIA USED :
FLUID : SELENITE F ENRICHMENT
SOLID: MAC CONKEY’S
DCA
SSA
STEPS : DIRECT PLATING + ENRICHMENT
CULTURE
• GROWTH FROM FLUID MEDIUM
SUBCULTURED ONTO MA
LAB DIAGNOSIS
• COLONIES ON MA/DCA : NLF PALE AND
TRANSLUCENT
• COLONIES PICKED UP FOR THE
FOLLOWING TESTS:
• HANGING DROP : NON MOTILE
• GRAM’S :GNB
• BIOCHEMICAL TESTS : IMVIC ++-ANEROGENIC FERMENTERS
• SLIDE AGGLUTINATION WITH SPECIFIC HTS
BIOCHEMICAL TESTS
SPECIES
GLUCOSE
S.DYS
ACID
S.FLEX
ACID
S.BOYDI
ACID
S.SONEI
ACID
LACTOSE
MANNITOL
INDOLE
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TREATMENT AND PREVENTION
• ANTIBIOTICS TO BE GIVEN BECAUSE
• 1. PERSON TO PERSON TRANSMISSION : INFECTED
PERSON IS THE RESERVOIR IN ORDER TO
PREVENT THE CHAIN OF TRANSMISSION
• GOOD SANITATION/SAFE DISPOSAL OF SEWAGE
• SAFE WATER SUPPLY
• SHIGELLA VACCINE (ORAL: STREP DEP
MUTANT:LIVE ATTEN)4 DOSES ; PROTECTION 6
MONTHS. EXP IN HYPERENDEMIC AREAS.
SALMONELLA
GASTROENTERITIS
• * FOOD POISONING
• ZOONOTIC INFECTION
• ANIMAL OR ANIMALPRODUCTS: MEAT
PRODUCTS, EGGS, CREAM, MILK (FOOD
CONTAMINATION WITH RAT OR LIZARD
DROPPINGS)
• S.TYPHIMURIUM/S.ENTERITIDIS,
S.NEWPORT
• IP 24 HOURS DIARRHOEA, VOMITTING, PAIN
ABDOMEN, FEVER