Genus BRUCELLAGenus BRUCELLADr.P.Sreenivasulu Reddy MD.,Dr.P.Sreenivasulu Reddy MD.,

Professor of MicrobiologyProfessor of MicrobiologyNARAYANA MEDICAL COLLEGENARAYANA MEDICAL COLLEGE

Nellore-1Nellore-1Andhra Pradesh INDIAAndhra Pradesh INDIA

Many Names of BrucellosisMany Names of Brucellosis

Human DiseaseHuman Disease Malta FeverMalta Fever Undulant FeverUndulant Fever Mediterranean FeverMediterranean Fever Rock Fever of GibraltarRock Fever of Gibraltar Gastric FeverGastric Fever

Animal DiseaseAnimal Disease Bang’s DiseaseBang’s Disease Enzootic AbortionEnzootic Abortion Epizootic AbortionEpizootic Abortion Slinking of CalvesSlinking of Calves Ram EpididymitisRam Epididymitis Contagious AbortionContagious Abortion

Sir William Burnett (1779-1861)

•Physician General to the British Navy

•Differentiated the various fevers affecting soldiers

•Contracted Malta

fever.

•Described his own case in great detail.

Jeffery Allen Marston

Sir David Bruce (1855-1931)

•British Army physician and microbiologist

•Discovered Micrococcus melitensis (July 9, 1887)

Bernhard Bang (1848-1932)

•Danish physician and veterinarian

•Discovered Bacterium abortus (1897) could infect cattle, horses, sheep and goats.

Alice Evans, American bacteriologistAlice Evans, American bacteriologist Credited with linking the organismsCredited with linking the organisms Similar morphology and pathology between:Similar morphology and pathology between:

Bang’s Bang’s Bacterium abortusBacterium abortus Bruce’s Bruce’s Micrococcus melitensisMicrococcus melitensis

Nomenclature today credited to Nomenclature today credited to Sir David Bruce Sir David Bruce Brucella abortusBrucella abortus and and Brucella melitensis.Brucella melitensis.

BrucellaBrucella spp. are small, spp. are small,

Gram-negative, non-motile, Gram-negative, non-motile,

non-spore-forming, non-spore-forming,

coccobacilli . coccobacilli .

Intracellular microbes Intracellular microbes

causing chronic disease.causing chronic disease.

Morphological Profile

Aerobe. Aerobe. Best medium is Best medium is Trypticase Soya Agar Trypticase Soya Agar with selective agents with selective agents (Polymyxin,Cyclohexamide).(Polymyxin,Cyclohexamide).

Small,moist,translucent Small,moist,translucent and glistening colonies and glistening colonies after 3 or more days of after 3 or more days of incubation.incubation.

Cultural charactersCultural characters

Species Biovar/Serovar

Natural Host Human Pathogen

B. abortus 1-6, 9 cattle yes

B.melitensis 1-3 goats, sheep yes

B. suis 1, 3 swine yes

2 hares yes

4 reindeer, caribou yes

5 rodents yes

B. canis none Dogs yes

B. ovis none Sheep no

B. neotomae none Desert wood rat no

B. maris (?) marine mammals ?

Biochemical reactionsBiochemical reactions

Catalase and Oxidase positive.Catalase and Oxidase positive.Nitrates are reduced.Nitrates are reduced.

Rapidly positive for urease. Rapidly positive for urease. Negative for IMViC reactions.Negative for IMViC reactions.

SusceptibilitySusceptibility Killed at 60Killed at 6000 C in 10 minutes C in 10 minutes Pasteurization of milk .Pasteurization of milk . Survival is long in refrigerated milk, Survival is long in refrigerated milk,

ice creams and cheese.ice creams and cheese.

Transmission to HumansTransmission to Humans

Conjunctiva or broken skin on contact with Conjunctiva or broken skin on contact with infected tissuesinfected tissues Blood, urine, vaginal discharges, aborted Blood, urine, vaginal discharges, aborted

fetuses, placentasfetuses, placentas Ingestion Ingestion

Raw milk & unpasteurized dairy products Raw milk & unpasteurized dairy products (Cheese)(Cheese)

Rarely through undercooked meatRarely through undercooked meat

Transmission to HumansTransmission to Humans Inhalation of infectious aerosolsInhalation of infectious aerosols

Pens, stables, slaughter housesPens, stables, slaughter houses Inoculation with vaccinesInoculation with vaccines

B. abortusB. abortus strain 19, RB-51 strain 19, RB-51 B. melitensisB. melitensis Rev-1 Rev-1 Conjunctival splashes, injectionConjunctival splashes, injection

Person-to-person transmission is rarePerson-to-person transmission is rare Incubation varies Incubation varies

5 days to three months5 days to three months

Transmission in AnimalsTransmission in Animals

Ingestion / contact with infected Ingestion / contact with infected tissues or body fluidstissues or body fluids Mucous membranes, injectionsMucous membranes, injections

VenerealVenereal Swine, sheep, goats, dogsSwine, sheep, goats, dogs FomitesFomites

Who is at Risk?Who is at Risk?

Occupational DiseaseOccupational Disease Cattle ranchers/dairy farmersCattle ranchers/dairy farmers Veterinarians Veterinarians Abattoir workersAbattoir workers Meat inspectorsMeat inspectors Lab workersLab workers

HuntersHunters TravelersTravelers Consumers of unpasteurized dairy productsConsumers of unpasteurized dairy products

Followed by Entry

Ingested by PMN and not killed (super oxide

dismutase ,LPS and nucleotide substance).

Spread to local LN, multiply and spread to blood.

Reaches to RES (Spleen,Liver,BM,LN).

Resist phagocytosis (production of AMP/GMP and TNF

Inhibits the phagolysosome fusion).

Spread (CNS,Heart,Joints,Respiratory,Skin,GU system)

Host response leads to granuloma formation and necrosis.

Pathogenecity and ImmunityPathogenecity and Immunity

B. abortusB. abortus

WorldwideWorldwide Some countries have Some countries have

eradicated iteradicated it Notifiable diseaseNotifiable disease

in many countriesin many countries abortions, arthritic joints.abortions, arthritic joints.

Fever of Unknown Origin (FUO)Fever of Unknown Origin (FUO)

Main causes for spontaneous abortion in animals are erythritol, which can promote infections in the fetus and placenta and lack of anti-Brucella antibody in amniotic fluid.

((Contagious/ Infectious abortion)Contagious/ Infectious abortion)

B. canisB. canis

Poorly understood Poorly understood 1-19% prevalence in United 1-19% prevalence in United

StatesStates contact with aborted contact with aborted

fetuses and semen.fetuses and semen. Rarely causes disease in Rarely causes disease in

humans.humans.

B. suisB. suis

Biovars 1 and 3Biovars 1 and 3 Worldwide problem.Worldwide problem.

FreeFree United Kingdom, Canada United Kingdom, Canada

EradicatedEradicated Holland, Denmark Holland, Denmark

Low IncidenceLow Incidence Middle East, North AfricaMiddle East, North Africa

Human DiseaseHuman Disease

Can affect any organ or systemCan affect any organ or system All patients have a cyclical feverAll patients have a cyclical fever

Headache, weakness, Headache, weakness, arthralgia, depression, arthralgia, depression, weight loss, fatigue, weight loss, fatigue, liver dysfunctionliver dysfunction

Human Disease Human Disease

20-60% of cases20-60% of cases Osteoarticular complicationsOsteoarticular complications

Arthritis, spondylitis, osteomyelitisArthritis, spondylitis, osteomyelitis Hepatomegaly may occurHepatomegaly may occur Gastrointestinal complicationsGastrointestinal complications 2-20% of cases2-20% of cases

Genitourinary involvementGenitourinary involvement Orchitis and epididymitis most commonOrchitis and epididymitis most common

Human DiseaseHuman Disease

NeurologicalNeurological Depression, mental fatigue Depression, mental fatigue

CardiovascularCardiovascular Endocarditis resulting in deathEndocarditis resulting in death

Chronic brucellosis is hard to defineChronic brucellosis is hard to define Length, type and response to treatment variableLength, type and response to treatment variable Localized infectionLocalized infection

Blood donations of infected persons should not Blood donations of infected persons should not be acceptedbe accepted

Human DiseaseHuman Disease

Congenitally infected infantsCongenitally infected infants Low birth weightLow birth weight Failure to thriveFailure to thrive JaundiceJaundice HepatomegalyHepatomegaly SplenomegalySplenomegaly Respiratory difficultyRespiratory difficulty General signs of sepsis (fever, vomiting)General signs of sepsis (fever, vomiting) AsymptomaticAsymptomatic

Chronic brucellosis:Chronic brucellosis: It is hard to define- Length, type and response to treatment variable

The localized form:The localized form: --Bones and joints. Bones and joints. -Lumbar spondylodiscitis, -Lumbar spondylodiscitis, sacroiliitis is typical. sacroiliitis is typical.-Orchitis also frequent.-Orchitis also frequent.

- Granulomatous hepatitis, - Arthritis, spondylitis, - Anaemia, leukopenia,thrombocytopenia, - Meningitis, uveitis, optic neuritis,

- Endocarditis.

Sequelae are highly variable

Granuloma of Liver

Diagnosis in HumansDiagnosis in Humans

Isolation of organismIsolation of organism Blood, bone marrow, other tissuesBlood, bone marrow, other tissues

Serum agglutination testSerum agglutination test Four-fold or greater rise in titerFour-fold or greater rise in titer Samples 2 weeks apartSamples 2 weeks apart

Immunofluorescence MethodImmunofluorescence Method Organisms in clinical specimensOrganisms in clinical specimens

PCRPCR

Blood cultures in Blood cultures in

trypticase soya broth trypticase soya broth

(Castaneda’s method):(Castaneda’s method):

Biphasic medium. Sample Biphasic medium. Sample

inoculated bottle has to be inoculated bottle has to be

tilted to flow the broth over tilted to flow the broth over

solid medium and keep it solid medium and keep it

upright position at 37upright position at 3700C. C.

The growth of brucellae is The growth of brucellae is

extremely slow. extremely slow.

Bone marrow cultures are Bone marrow cultures are

more sensitive than blood.more sensitive than blood.

ELISAELISA is the best method. is the best method.

Standard tube agglutination test:Standard tube agglutination test: Anti -O-polysaccharide of LPS. Killed Anti -O-polysaccharide of LPS. Killed strains of B. abortus as antigen. Not strains of B. abortus as antigen. Not useful for B.canis.useful for B.canis.

Modified Tube agglutination testModified Tube agglutination test:: 2-mercaptoethanol is added to serum 2-mercaptoethanol is added to serum before testing which causes disruption before testing which causes disruption of IgM and only IgG are detected. of IgM and only IgG are detected.

Problems with TA test:Problems with TA test: Prozone phenomenon, Presence of blocking or non-agglutinating antibodies. False positives with cholera, tularemia,yersinia or Prozone phenomenon, Presence of blocking or non-agglutinating antibodies. False positives with cholera, tularemia,yersinia or

vaccinationvaccination..

Demonstration of Demonstration of IgM , IgG and Ig AIgM , IgG and Ig A

Contd…..

Castaneda strip test:Castaneda strip test: Strip with colored brucella Strip with colored brucella

antigen. On addition of patients serum, if antibodies antigen. On addition of patients serum, if antibodies

are present, prevents the flow of serum. are present, prevents the flow of serum.

Brucellin Skin test:Brucellin Skin test: Delayed hypersensitivity. Delayed hypersensitivity.

Molecular techniques:Molecular techniques: PCR PCR

Radiology:Radiology: Alterations in infected vertebrae; Alterations in infected vertebrae; Pedro Pedro

Pons signPons sign ( erosion of antero-superior corner of lumbar vertebrae)( erosion of antero-superior corner of lumbar vertebrae) and marked osteophytosis are and marked osteophytosis are

suspecious of brucellic spondylitis. suspecious of brucellic spondylitis.

Culture of urine and Milk.

Rapid latex agglutination test,

Rose Bengal card test. (Rose Bengal +

B.abortus + Sodium azide)

Diagnosis in AnimalsDiagnosis in Animals

Contd….

Milk Ring Test: Frequently used test. A drop of colored brucella antigen (B.abortus/B.melitensis with hematoxylin) is added to milk in a test tube, incubated in a water bath at 700C for 40-50 minutes. Positive: Blue ring at the top leaving the milk unstained. Negative: No ring. Milk remains uniformly blue.

Treatment of ChoiceTreatment of Choice

Combination therapy has the best efficacyCombination therapy has the best efficacy Doxycycline for 6 weeks in combination with Doxycycline for 6 weeks in combination with

Streptomycin for 2-3 weeks or Rifampin for 6 Streptomycin for 2-3 weeks or Rifampin for 6 weeksweeks

CNS cases to treat for 6-9 months.CNS cases to treat for 6-9 months. Same for endocarditis cases plus surgical Same for endocarditis cases plus surgical

replacement of valves.replacement of valves.

PrognosisPrognosis

May last days, months, or yearsMay last days, months, or years Recovery is commonRecovery is common Disability is often pronounced Disability is often pronounced About 5% of treated cases relapseAbout 5% of treated cases relapse

Failure to complete the treatment regimenFailure to complete the treatment regimen Sequestered infection requiring surgical drainageSequestered infection requiring surgical drainage

Case-fatality rate: <2% ( untreated)Case-fatality rate: <2% ( untreated) Endocarditis caused by Endocarditis caused by B. melitensisB. melitensis

Prevention and ControlPrevention and Control

Education about risk of transmissionEducation about risk of transmission Farmer, veterinarian, abattoir worker, Farmer, veterinarian, abattoir worker,

butcher, consumer, hunter, publicbutcher, consumer, hunter, public Wear proper attire if dealing with Wear proper attire if dealing with

infected animals/ tissuesinfected animals/ tissues Gloves, masks, gogglesGloves, masks, goggles

Avoid consumption of raw dairy Avoid consumption of raw dairy productsproducts

Prevention and ControlPrevention and Control

Immunize in areas of high prevalenceImmunize in areas of high prevalence Young goats and sheep with Rev-1Young goats and sheep with Rev-1 Calves with RB51 Calves with RB51 No human vaccineNo human vaccine

Eradicate reservoir Eradicate reservoir Identify, segregate, and / or cull Identify, segregate, and / or cull

infected animalsinfected animals

References:References:

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