Listeria by akram.ppt - Mymensingh Medical College file/Listeria by akram.pdf · Bil Mar Foods Outbreak, Bil Mar Foods Outbreak, 1998 1998--19991999 101 101 cases cases 21 21 deaths

Listeria

Prof. Md . Akram HossainJuly 2009

12/25/2013 1Prof. Muhammad Akram Hossain, Listeria

Listeria – the organism

• Gram positive, short,non-sporing rods

• Catalase positive andfacultatively anaerobic

• Grow in commonmediamedia

• Motile at 25oC butnon-motile at 35oC

• Exhibits “tumbling” or“umbrella” motility


HISTORY OF LISTERIA MONOCYTOGENES

• 1918: Isolated from cerebrospinal fluid (WWI soldier);menengitis; identified as L. monocytogenes(1940)

• 1926: Sudden death of young rabbits; mononuclearleucocytosis; documented isolation (Murray et al.):Bacteriummonocytogenes

• 1927: Unusual death of gerbils, Johannesburg, SouthAfrica ; Tiger River Disease ; Listeria hepatolytica (LordAfrica ; Tiger River Disease ; Listeria hepatolytica (LordLister)

• 1929: Human pathogen; Listerella monocytogenes

• 1940: Named Listeria monocytogenes; Listerella hadbeen used for a mold in honor of brother Arthur andfather Joseph Lister; many other names; cause ofQueen Ann’s 17 miscarriages in 17thcentury?

• 1979: Recognized as emerging food bornepathogen


Food borne Illness in the United States

• Illnesses per year: 75,814,924 (7.5 crore)• Hospitalizations: 323,854 (3.2 lakh)• Deaths: 5,209

• Costs:$8.4 Billion

• Pathogen Illnesses Fatality (%) Deaths

• Campylobacter 2,453,926 <0.05 124

• Salmonella 1,413,322 <0.0 5 585

• Esc coli 73,480 0.1 61

• L. monocytogenes 2,518 20 504


• Heat resistance among vegetative Gram positive bacteria

• Exhibits resistance to gamma irradiation• Large pH range from pH 4.6 to pH 9.2• Grow well at 37oC but also able to grow • Grow well at 37oC but also able to grow

at– Frozen conditions –18 oC in various food

substrates– 0oC in sterile foods having neutral pH– 4oC in ground beef


Umbrella Motility


Species of Listeria

• *** L.monocytogenes• L.innocua• L.seeligeri• L.welshimeri• L.welshimeri• L.ivanovii• L.grayi• L.murrayi


L. monocytogenes has the ability to multiply at lowtemperatures. The bacteria may therefore grow and accumulate in contaminated food stored in the refrigerator. So listeriosis is usually associated with ingestion of milk, meat or vegetable products that have been held at refrigeration temperatures for a long period of time.

12/25/2013 8Prof. Muhammad Akram Hossain,

Listeria

Virulence factors

1. Monocytosis producing agent

2. Internalins (InlA)

3. Oxygen labile hemolysin calledlisteriolysin (LLO)listeriolysin (LLO)

4. Phospholipase

5. Listeric polysaccharide –

6. ActA


Listeria

Virulence factors

� Monocytosis producing agent – is a lipid released

by mechanical disruption of the cells.

� It causes a monocytosis to occur in the host

� Internalins (InlA)– are surface associated proteins� Internalins (InlA)– are surface associated proteins

that act to facilitate the uptake of the bacteriuminto epithelial cells.

� Oxygen labile hemolysin called listeriolysin (LLO)

� It is a pore forming toxin that facilitates the escape ofthe organism from the endosome to the cytosol


Listeria

Listeria

� Phospholipase – is also involved in

facilitating the escape of the organismfrom the endosome to the cytosol.

Listeric polysaccharide – is a capsule� Listeric polysaccharide – is a capsule

component

� ActA – a surface protein that facilitates the

rearrangement of actin to propel theorganism through the cell and into anadjacent cell (organism is very invasive)


Listeria

Listeria and actin polymerization


Listeria

Listeria invasion


Listeria

Intracellular cell


Listeria

Listeria attaches to a cell and there's a microbial gene

product called internalin that aids in that process.


Listeria

Listeria is enclosed within a vacuole, a phagocytic vacuole initially A very important virulence factor, Listeriolysin-O or LLO, causes the lysis of this membrane


Listeria

Listeria divides in the cytoplasm and begins to polymerize host cell actin. A gene product called Act-A is involved in this process


Listeria

A comet-like tail forms that propels the Listeria through the cell and into the adjacent cell


Listeria

The double-walled membrane is disrupted by both listeriolysin-O and phospholipases that are elaborated by the bacteria.


Listeria

The cycle is then repeated.Listeria can get into a cell, then into the cytoplasm, then into another cell without ever being in contact with the external environment.


Listeria


Listeria


Listeria


Listeria

Epidemiology

• Widely distributed in the environment– Soil– Mud– Silage– Water

• Modes of Transmission• Modes of Transmission– Refrigerated foods and ready-to-eat meats that are

contaminated– Unpasteurized milk and milk products– Mom to fetus– Contaminated equipment– Infected animal materials


Epidemiology..

• Listeria monocytogenes is ubiquitous in the environment.1

– animals, birds, insects, soil and wastewater, and vegetation. and vegetation.

• In raw milk, supposedly pasteurized fluid milk, cheeses (particularly soft-ripened varieties), ice cream, raw vegetables, fermented raw-meat sausages, raw and cooked poultry, raw meats (all types), and raw and smoked fish.


Epidemiology (..)

• Incubation period = 3-70 days– Median is 3 weeks

• Infectious period– Pregnancy – 7-10 days following

deliverydelivery– Infected individuals – shed organism for

several months


Clinical Description

• Gastroenteritis• Septicemia• Meningitis and encephalitis• Pregnancy

– Infection of the fetus– Infection of the fetus– Abortion– Stillbirth– Premature birth

• High case fatality rate


Listeria Listeria monocytogenesmonocytogenesRarely causes disease in healthy Rarely causes disease in healthy nonnon--pregnant personspregnant persons

Pregnant women account for Pregnant women account for 11//3 3 of of 22,,500 500 cases/yearcases/year

Incidence Incidence 1212xs higher in Hispanic pregnant xs higher in Hispanic pregnant

28

Incidence Incidence 1212xs higher in Hispanic pregnant xs higher in Hispanic pregnant women and infants than Nonwomen and infants than Non--HispanicHispanic

Rest occur in neonates, elderly and Rest occur in neonates, elderly and immuneimmune--compromised populationscompromised populations

2020% death rate% death rate

FAO/WHO, FAO/WHO, 20022002; Mead et al., ; Mead et al., 19991999, Smith, , Smith, 199919991212//2525//20132013 28

Initial symptoms:Initial symptoms:

��Mild gastrointestinal symptoms Mild gastrointestinal symptoms 88--48 48 hours after hours after exposure to contaminated foodexposure to contaminated food

��May or may not progress to invasive listeriosis, May or may not progress to invasive listeriosis, but can still pass to fetusbut can still pass to fetus

Listeria monocytogenesListeria monocytogenes

29

but can still pass to fetusbut can still pass to fetus

Invasive listeriosis symptoms:Invasive listeriosis symptoms:

��Appear Appear 22--6 6 weeks after exposure to contaminated weeks after exposure to contaminated foodfood

��Very serious illness with fever, chills, headache, Very serious illness with fever, chills, headache, muscle aches, loss of balance, bacteremia muscle aches, loss of balance, bacteremia

Smith, Smith, 199919991212//2525//20132013 29

ListeriosisListeriosis and Pregnancyand Pregnancy

Timing of infection can determine impact on Timing of infection can determine impact on mother and childmother and child

ListeriosisListeriosis early in pregnancy rare:early in pregnancy rare:

��Associated with septic abortion or stillbirthAssociated with septic abortion or stillbirth

30

��Associated with septic abortion or stillbirthAssociated with septic abortion or stillbirth

ListeriosisListeriosis late in pregnancy more common:late in pregnancy more common:

��Associated with premature delivery, stillbirth, Associated with premature delivery, stillbirth, septicemia, baby born with health issuessepticemia, baby born with health issues

Silver, Silver, 19981998; Smith, ; Smith, 19991999

1212//2525//20132013 30

Neonatal Listeriosis Neonatal Listeriosis – – Early OnsetEarly Onset

Infection of infant caused by transmission Infection of infant caused by transmission from mom across placentafrom mom across placenta

Symptoms seen in first Symptoms seen in first 55--7 7 days of birthdays of birth

��Low birth weight, septicemiaLow birth weight, septicemia

31

��Respiratory distress, pneumoniaRespiratory distress, pneumonia

��Mental retardation, meningitis, blindnessMental retardation, meningitis, blindness

��Survival as low as Survival as low as 5050% %

Mother had Mother had listeriosislisteriosis in in 5050--7575% of cases% of casesSmith, Smith, 19991999

Temple & Temple & NahataNahata, , 200020001212//2525//20132013 31

Neonatal Listeriosis Neonatal Listeriosis – – Late OnsetLate OnsetInfection of infant occurs during or after deliveryInfection of infant occurs during or after delivery�� Vertical transmission during birthingVertical transmission during birthing

�� Acquired from infected hospital caretaker Acquired from infected hospital caretaker or other infantor other infant

�� Acquired from hospital or home environmentAcquired from hospital or home environment

Symptoms develop >Symptoms develop >55--14 14 days post deliverydays post delivery

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Symptoms develop >Symptoms develop >55--14 14 days post deliverydays post delivery�� Rash with feverRash with fever

�� Septicemia, MeningitisSepticemia, Meningitis

�� Lower mortality (~Lower mortality (~1010%)%)

Mom less likely to have symptoms of Mom less likely to have symptoms of listeriosislisteriosis

Smith, Smith, 19991999, Temple & , Temple & NahataNahata, , 20002000

1212//2525//20132013 32

The main target populations for listeriosis are:

pregnant women/fetus

persons immunocompromised bycorticosteroids, anticancer drugs, graftsuppression therapy, AIDSsuppression therapy, AIDS

cancer patients

the elderly;

normal people who used the foodstuff washeavily contaminated with the organism.


Listeria

Lab diagnosis

Principle: Lab diagnosis is based onMicroscopy and culture.

Steps:– Specimens: based on site of infection,

CSF, blood etcCSF, blood etc– Microscopy- Gram positive short bacilli– Culture- In Blood agar media

betahemolytic colonies with motility at250C


Listeriosis: IncidenceListeriosis: Incidence

�� FoodNet Data FoodNet Data 20032003�� Incidence rate of Incidence rate of 00..33 33 cases/cases/100100,,000 000

populationpopulation�� Case fatality rate was highest Case fatality rate was highest -- 1717%%�� Rate of hospitalization was highest Rate of hospitalization was highest -- 9191%%�� Incidence has decreased from Incidence has decreased from 1996 1996 by by 2121%%

�� Incidence target for Incidence target for 20102010�� 00..25 25 cases/cases/100100,,000 000 populationpopulation

1212//2525//20132013 3535Prof. Muhammad Akram Hossain, Prof. Muhammad Akram Hossain, ListeriaListeria

Listeriosis: OutbreaksListeriosis: Outbreaks

�� Coleslaw Coleslaw –– 1981 1981 ((9 9 deaths)deaths)�� Pasteurized milk Pasteurized milk –– 1983 1983 ((14 14 deaths)deaths)�� Mexican style soft cheese Mexican style soft cheese -- 1985 1985 ((48 48 �� Mexican style soft cheese Mexican style soft cheese -- 1985 1985 ((48 48

deaths)deaths)�� Hotdogs and deli meats Hotdogs and deli meats –– 19981998--1999 1999 ((20 20

deaths)deaths)�� ReadyReady--toto--eat turkey and chicken eat turkey and chicken

products products –– 2002 2002 ((10 10 deaths)deaths)


Listeriosis: OutbreaksListeriosis: Outbreaks

�� Largest OutbreakLargest Outbreak�� Bil Mar Foods Outbreak, Bil Mar Foods Outbreak, 19981998--19991999

�� 101 101 casescases

�� 21 21 deathsdeaths�� Rare strain of Rare strain of L. monocytogenesL. monocytogenes 44bb

�� Recalled Recalled 35 35 million pounds of hot dogs and million pounds of hot dogs and deli meatsdeli meats


Outbreaks…

Germany (1953) Pregnant woman who drankraw milk from cow with mastitis gavepremature birth to stillborn twins.

Sweden (1959) 4 cases:3 infants, 1 adults, 1infant deaths.infant deaths.

New Zealand (1980) 22 cases who ateshellfish and raw milk

Los Angeles (1985) 142 cases who usedMexican-style cheese contaminated with rawmilk.

Philadelphia (1986-1987) 36 cases – icecream, salami or vegetables suspected.12/25/2013 38

Prof. Muhammad Akram Hossain, Listeria

Treatment

� Antimicrobic susceptibility/treatment� Prognosis is poor in neonates so infected moms

should be treated as soon as disease isdiagnosed

� Penicillin is the drug of choice.

� Can also use erythromycin or tetracycline.


Listeria

Prevention

Avoid eating raw or improperly cooked foodsof animal origin

Avoid cross contamination between raw andcooked foodscooked foods

Raw vegetables should be thoroughly washedbefore eating

Foods should be used before “best before”code on the package

Maintain the clean refrigerator


Listeria

QuestionsQuestions


Documents

Listeria by akram.ppt - Mymensingh Medical College file/Listeria by akram.pdf · Bil Mar Foods Outbreak, Bil Mar Foods Outbreak, 1998 1998--19991999 101 101 cases cases 21 21 deaths