Genital Mycoplasmal Genital Mycoplasmal Disease in the NewbornDisease in the Newborn

John Baier M.D.John Baier M.D.

University of ManitobaUniversity of Manitoba

Characteristics of Characteristics of MycoplasmasMycoplasmas

Mycoplasmas are the smallest self replicating Mycoplasmas are the smallest self replicating organismsorganisms

Do not have a cell wall like other bacteriaDo not have a cell wall like other bacteria• Do not Gram stainDo not Gram stain

Small genome and lack enzymes needed to Small genome and lack enzymes needed to synthesize may compoundssynthesize may compounds

• Complex nutritional requirements Complex nutritional requirements

• Require host cells and their productsRequire host cells and their products

• Difficult to culture outside of hostsDifficult to culture outside of hosts

• Will not grow on routine bacteriologic mediaWill not grow on routine bacteriologic media

Mycoplasmas in Human Mycoplasmas in Human DiseaseDisease

Difficulties in culturing have made establishing a Difficulties in culturing have made establishing a pathogenic role of mycoplasmas difficultpathogenic role of mycoplasmas difficult

Diseases caused by mycoplasmasDiseases caused by mycoplasmas• acute acute Mycoplasma pneumoniaeMycoplasma pneumoniae

• often subacute or chronicoften subacute or chronic

• lack well defined clinical presentationslack well defined clinical presentations

Mycoplasmas in Human Mycoplasmas in Human DiseaseDisease

Diseases potentially caused by mycoplasmasDiseases potentially caused by mycoplasmas• Periodontal diseasePeriodontal disease Mycoplasma salivariumMycoplasma salivarium

• ArthritisArthritis Mycoplasma arthitidis, Mycoplasma Mycoplasma arthitidis, Mycoplasma fermentansfermentans

• Urethritis, cervicitisUrethritis, cervicitis Mycoplasma hominis, Mycoplasma hominis, Ureaplasma Ureaplasma urealyticumurealyticum

• PrematurityPrematurity Mycoplasma hominis, Mycoplasma hominis, Ureaplasma Ureaplasma urealyticumurealyticum

• Recurrent pregnancy lossRecurrent pregnancy loss Mycoplasma hominis, Ureaplasma Mycoplasma hominis, Ureaplasma urealyticumurealyticum

• AIDS related diseasesAIDS related diseases Mycoplasma penetrans, Mycoplasma Mycoplasma penetrans, Mycoplasma fermentansfermentans

• Chronic lung diseaseChronic lung disease Mycoplasma hominis, Mycoplasma hominis, Ureaplasma Ureaplasma urealyticumurealyticum

Mycoplasmas Colonizing Mycoplasmas Colonizing the Genital Tractthe Genital Tract

Ureaplasma urealyticum/ Ureaplasma parvumUreaplasma urealyticum/ Ureaplasma parvum• premature laborpremature labor• pneumoniapneumonia• meningitismeningitis• BPDBPD

Mycoplasma hominisMycoplasma hominis• premature laborpremature labor• pneumoniapneumonia• meningitismeningitis• BPD?BPD?

Mycoplasma fermentansMycoplasma fermentans• no known association with perinatal diseaseno known association with perinatal disease

Mycoplasma genitaliumMycoplasma genitalium• Only detectable by PCROnly detectable by PCR• no known association with perinatal diseaseno known association with perinatal disease

Epidemiology of Genital Epidemiology of Genital Tract MycoplasmasTract Mycoplasmas

Commonly foundCommonly found• 40-80% pregnancies colonized with 40-80% pregnancies colonized with Ureaplasma urealyticumUreaplasma urealyticum

• 5-50% pregnancies colonized with 5-50% pregnancies colonized with Mycoplasma hominisMycoplasma hominis

Increased colonization withIncreased colonization with• increased number of sexual partnersincreased number of sexual partners

• earlier age of first intercourseearlier age of first intercourse

• isolation of other STDs (isolation of other STDs (Chlamydia trachomatisChlamydia trachomatis))

Transmission of Transmission of Ureaplasma Ureaplasma urealyticumurealyticum to the Newborn to the Newborn

Vertical transmissionVertical transmission• 18-55% in term infants18-55% in term infants

• 29-55% in preterm infants29-55% in preterm infants

Factors that increase chance of transmission to Factors that increase chance of transmission to fetusfetus

• rupture of membranesrupture of membranes

• chorioamnionitis chorioamnionitis

• vaginal deliveryvaginal delivery

Transmission rate varies with gestational ageTransmission rate varies with gestational age Once acquired colonization of respiratory tract Once acquired colonization of respiratory tract

may persist for months untreatedmay persist for months untreated

Perinatal Transmission of Perinatal Transmission of UreaplasmaUreaplasma to Newborn to Newborn

010

20304050

607080

90100

Per

cent

Tra

nsm

issi

on

<1500 1501-2000

2001-2500

2501-3000

3001-3500

3001-3500

>3500

Birth WeightKlein JO 1969

Consequences of Genital Consequences of Genital Mycoplasma Infections in the Mycoplasma Infections in the

NewbornNewborn

Variable response to infectionVariable response to infection• self limited with no long term effectsself limited with no long term effects

• acute pneumoniaacute pneumonia

• chronic inflammatory response may lead to chronic inflammatory response may lead to development of chronic lung diseasedevelopment of chronic lung disease

Ureaplasma urealyticumUreaplasma urealyticum as a as a cofactor in the development of cofactor in the development of

BPDBPD BPD is a multifactorial diseaseBPD is a multifactorial disease

• Uu is not THE CAUSE of BPDUu is not THE CAUSE of BPD

Conflicting data in the literatureConflicting data in the literature• different culture sites/methodsdifferent culture sites/methods

– single culture vs. multiple culturesingle culture vs. multiple culture

– tracheal aspirate vs. nasal aspiratetracheal aspirate vs. nasal aspirate

– reliability of culturesreliability of cultures

– PCR vs. culturePCR vs. culture

• different populationsdifferent populations

– not a disease of larger infantsnot a disease of larger infants• colonization with Uu is of no significance (generally) in a otherwise colonization with Uu is of no significance (generally) in a otherwise

healthy term infanthealthy term infant

– different frequencies of organisms causing preterm birth different frequencies of organisms causing preterm birth

Ureaplasma urealyticumUreaplasma urealyticum as a cofactor as a cofactor in the development of BPDin the development of BPD

Overall, isolation of Uu Overall, isolation of Uu from airways is from airways is associated with a 2-3 associated with a 2-3 fold increase in the fold increase in the incidence of oxygen incidence of oxygen dependency at 28 days dependency at 28 days of ageof age

Associated with a lesser Associated with a lesser but still significant but still significant increase in the incidence increase in the incidence of oxygen dependency of oxygen dependency at 36 weeks PCAat 36 weeks PCA

01020

30405060

708090

100

Per

cen

t B

PD

Uu present

Uu absent

LSU 1992-94LSU 1992-94

*

*p<0.001

Mechanisms of lung injury Mechanisms of lung injury caused by Mycoplasmascaused by Mycoplasmas Live and heat killed mycoplasmas induce inflammatory Live and heat killed mycoplasmas induce inflammatory

cytokine production in a variety of lung cell typescytokine production in a variety of lung cell types• mononuclear cells (alveolar macrophages)mononuclear cells (alveolar macrophages)

• respiratory epitheliumrespiratory epithelium

• fibroblastsfibroblasts

In most mycoplasmas the cytokine inducing activity is In most mycoplasmas the cytokine inducing activity is been determined to be membrane lipoproteinsbeen determined to be membrane lipoproteins

• slight similarity to LPSslight similarity to LPS

• utilize LPS receptors (toll like receptors)utilize LPS receptors (toll like receptors)

The component that stimulates cytokine production has The component that stimulates cytokine production has not been determined for not been determined for Ureaplasma urealyticumUreaplasma urealyticum

In vitroIn vitro infection with infection with U. urealyticumU. urealyticum preterm monocyte cytokine releasepreterm monocyte cytokine release

Monocytes from preterm cord blood (24 to 32 weeks) were incubated with CRPMI-10% FCS alone, U. urealyticum at 103 CCU (UU3) (low inoculum) or 106 CCU (UU6) (high inoculum), or LPS (100 ng/ml) with or without U. urealyticum for 24 h. (A) TNF-  ; (B) IL-6; (C) IL-10; (D) IL-8. Results are expressed as percentages of the LPS positive control value n = 6). *, P < 0.05 versus medium control; , P < 0.05 versus LPS.

Pulmonary Inflammation and isolation of Pulmonary Inflammation and isolation of Ureaplasma urealyticumUreaplasma urealyticum

0

500

1000

1500

2000

2500

3000

MC

P-1

pg

/ug

Sec

1 3 5 9 14 21

Age (Days)

No UuUu

Induction of CC chemokines by Induction of CC chemokines by M hominis and U M hominis and U urealyticum:urealyticum:

Cord blood mononuclear cellsCord blood mononuclear cells

0

1000

2000

3000

4000

5000

6000

7000

8000

Cyto

kin

e (

pg/m

l)

Control Uu Control Mh

MIP-1 alphaMIP-1 betaMCP-1MCP-2MCP-3

UuUu increases inflammatory increases inflammatory responses in animal modelsresponses in animal models

Yoder et al 2003Yoder et al 2003• Intra-amniotically infected premature baboonsIntra-amniotically infected premature baboons

• Increased inflammatory cell infiltrate in Increased inflammatory cell infiltrate in UuUu +ve animals compared to +ve animals compared to controls of controls of UuUu – ve animals – ve animals

• Predominately monocytic cellsPredominately monocytic cells

Factors determining “pathogenicity” of Factors determining “pathogenicity” of Genital MycoplasmasGenital Mycoplasmas

Gestational ageGestational age• animal models suggest that immature animals develop more severe diseaseanimal models suggest that immature animals develop more severe disease

• clinically this is a disease of the smallest infantsclinically this is a disease of the smallest infants

– reduced transfer of maternal IgGreduced transfer of maternal IgG

– immature immune responsesimmature immune responses

Surfactant deficiencySurfactant deficiency• infants with mature lungs rarely develop problemsinfants with mature lungs rarely develop problems

• lack of mycoplasmacidal effects of surfactant proteinslack of mycoplasmacidal effects of surfactant proteins

Oxygen administration/Mechanical ventilationOxygen administration/Mechanical ventilation• synergistic effect between oxygen and infectionsynergistic effect between oxygen and infection

Maternal immune responseMaternal immune response• low antibody production in mother increases risk of disease in newbornlow antibody production in mother increases risk of disease in newborn

Genetic Factors?Genetic Factors?• Variations in cytokine or pathogen pattern recognition genesVariations in cytokine or pathogen pattern recognition genes

– IL-1RA (maternal)IL-1RA (maternal)

– TLR2TLR2

Biovar or serotype does not play a roleBiovar or serotype does not play a role• no specific pathogenicity factor knownno specific pathogenicity factor known

Surfactant protein A: Surfactant protein A: mediation of mediation of mycoplasmacidal activity of alveolar mycoplasmacidal activity of alveolar

macrophagesmacrophages

Hickman-Davis et al 1998

Clinical Presentation Clinical Presentation

Transient colonizationTransient colonization Non resolving HMD/Persistent Non resolving HMD/Persistent

colonizationcolonization Rapid development of BPD like changesRapid development of BPD like changes Pneumonia Pneumonia PPHN (rare)PPHN (rare) Apnea Apnea

Transient respiratory Transient respiratory tract colonizationtract colonization

Incidence is not knownIncidence is not known May constitute ~ 25% of culture positive infantsMay constitute ~ 25% of culture positive infants Present with mild-moderate respiratory distressPresent with mild-moderate respiratory distress

• HMD or TTNHMD or TTN

• Positive culture for Uu/Mh incidentalPositive culture for Uu/Mh incidental

Rapid resolution without sequelaeRapid resolution without sequelae Culture results return after patient is extubated Culture results return after patient is extubated

and relatively welland relatively well Require no treatmentRequire no treatment

Non resolving HMD/Persistent Non resolving HMD/Persistent colonizationcolonization

Represents largest proportion of infantsRepresents largest proportion of infants Initial presentation of typical HMDInitial presentation of typical HMD Incomplete resolutionIncomplete resolution May have multiple cultures positiveMay have multiple cultures positive

• initial may be negativeinitial may be negative

Infants with persistent Infants with persistent UuUu are are more likely to develop BPDmore likely to develop BPD

Ou

tco

me

(p

erc

en

t)

0

20

40

60

80

100

Follow up Uu culturenegative or indeterminate

Follow up Uu culturepositive

O2 at 28 daysO2 at 36 weeks

Baier RJ et al 2003

Rapid development of Rapid development of BPD like changesBPD like changes

Initial presentation of typical HMDInitial presentation of typical HMD• does not have to be severedoes not have to be severe

Poor resolutionPoor resolution Development of cystic appearance by first weeks Development of cystic appearance by first weeks

of lifeof life• can be confused with PIEcan be confused with PIE

• likely represents pneumonialikely represents pneumonia

Worse prognosis?Worse prognosis?

Ureaplasmal pneumoniaUreaplasmal pneumonia

May present at birthMay present at birth• indistinguishable from HMDindistinguishable from HMD

• pneumonic appearancepneumonic appearance

May present several weeks after birthMay present several weeks after birth• apneaapnea

• respiratory distressrespiratory distress

• may progress to chronic lung diseasemay progress to chronic lung disease

No other agent is culturedNo other agent is cultured

Adverse CNS Outcomes in infants with Adverse CNS Outcomes in infants with Ureaplasma urealyticumUreaplasma urealyticum

0

10

20

30

40

50

60

70

Inci

den

ce (

%)

All IVH Severe IVH Hydrocephalus Shunt

Uu Positive

Uu Negative

*

*

*

*p<0.02

Interaction between isolation of Interaction between isolation of UuUu and IL-1and IL-1 –511T polymorphism –511T polymorphism

0

5

10

15

20

25

30

35

40

45

Inc

ide

nc

e (

%)

IVH PVL IVH or PVL

Uu negative and 511T negative Uu negative and 511T positiveUu Positive and 511T neagtive Uu Positive and 511T positive

Diagnosis and Diagnosis and Management of Management of

Mycoplasmal InfectionsMycoplasmal Infections

Diagnosis of Genital Diagnosis of Genital Mycoplasma infectionsMycoplasma infections

Who to culture?Who to culture?• RoutineRoutine

– Infants with birth weight less than 1500 gramsInfants with birth weight less than 1500 grams

– mechanical ventilationmechanical ventilation

– preterm labor ± ROM, chorioamnionitispreterm labor ± ROM, chorioamnionitis

• Suspect genital mycoplasmasSuspect genital mycoplasmas

– early BPD like changesearly BPD like changes

– non resolution of HMDnon resolution of HMD

– culture negative pneumoniaculture negative pneumonia

Diagnosis of Genital Diagnosis of Genital Mycoplasma infectionsMycoplasma infections

What to culture?What to culture?• Tracheal aspirateTracheal aspirate

• Blood ?Blood ?

• Little predictive value of positive cultures from nose, throat, Little predictive value of positive cultures from nose, throat, rectum, gastric aspiraterectum, gastric aspirate

Value of repeated cultures?Value of repeated cultures?• Persistent positive cultures correlate better with development Persistent positive cultures correlate better with development

of BPDof BPD

• frequently initial culture at birth may be negativefrequently initial culture at birth may be negative

• 3x during first week if intubated3x during first week if intubated

Diagnosis of Genital Diagnosis of Genital MycoplasmasMycoplasmas

Culture methodsCulture methods• Mycoplasmas are not hardy Mycoplasmas are not hardy

organisms organisms – fresh specimensfresh specimens

• specialized transport mediaspecialized transport media– frozenfrozen– bloodblood– CSFCSF

• frequently there are natural frequently there are natural inhibitors to growthinhibitors to growth

– serial dilutionsserial dilutions– multiple mediamultiple media

• cultures are difficult to interpretcultures are difficult to interpret– require microscopic require microscopic

examination of colony examination of colony formationformation

– color change in media may be color change in media may be from other organismsfrom other organisms

Polymerase Chain Reaction (PCR)Polymerase Chain Reaction (PCR) UreaplasmaUreaplasma

• Urease geneUrease gene

• Multiple banded antigenMultiple banded antigen

– distinguishes between distinguishes between U. urelyticum and U. parvumU. urelyticum and U. parvum

Mycoplasma hominisMycoplasma hominis• 16S rRNA gene16S rRNA gene

Diagnosis of Genital Diagnosis of Genital MycoplasmasMycoplasmas

PCR for Ureaplasma based on Urease gene

PCR vs CulturePCR vs Culture

PCRPCR• rapid results <24 hoursrapid results <24 hours

• biovar informationbiovar information

• very sensitivevery sensitive

– relevance of detecting ~ 10 organismsrelevance of detecting ~ 10 organisms

CultureCulture• may take longer than a week for positive IDmay take longer than a week for positive ID

• no biovar informationno biovar information

• false negatives may be common depending on lab false negatives may be common depending on lab experience and specimen handlingexperience and specimen handling

• less sensitiveless sensitive

– detects larger numbers of viable organismsdetects larger numbers of viable organisms

Treatment StrategiesTreatment Strategies

Should you treatShould you treat

Whom to treat?Whom to treat?

What to treat with?What to treat with?

Treatment of Genital Treatment of Genital MycoplasmasMycoplasmas

Treatment of genital mycoplasmas is Treatment of genital mycoplasmas is controversialcontroversial

No studies have been done to show that it alters No studies have been done to show that it alters outcomeoutcome

• diagnosis and treatment is often delayeddiagnosis and treatment is often delayed

– not considerednot considered

– cultures take 5-7 dayscultures take 5-7 days

• distinguishing between colonization and infectiondistinguishing between colonization and infection

• strains ofstrains of Ureaplasma Ureaplasma may be resistant to antimicrobialsmay be resistant to antimicrobials

Treatment of Genital Treatment of Genital Mycoplasmas: StrategiesMycoplasmas: Strategies Empiric treatment of at risk infantsEmpiric treatment of at risk infants

• no studiesno studies

• possible benefit of early treatmentpossible benefit of early treatment

• treatment of infants who won’t develop disease with broad treatment of infants who won’t develop disease with broad spectrum antibioticsspectrum antibiotics

– increased risk to develop yeast infections?increased risk to develop yeast infections?

Treatment of culture positive or persistently Treatment of culture positive or persistently positive infantspositive infants

• delay of treatment after much of the damage may be donedelay of treatment after much of the damage may be done

• the few studies done show little or no benefitthe few studies done show little or no benefit

Treatment of Genital Treatment of Genital MycoplasmasMycoplasmas

Ureaplasma urealyticumUreaplasma urealyticum• sensitive to macrolide sensitive to macrolide

antibioticsantibiotics• erythromycin 30-40 mg/kg/dayerythromycin 30-40 mg/kg/day

– 10-14 days (no studies)10-14 days (no studies)– Failure to clear organismFailure to clear organism

• azithromycinazithromycin– no datano data– 10mg/kg day 1 then 10mg/kg day 1 then

5/mg/kg/day x 6days?5/mg/kg/day x 6days?• insensitive to clindamycininsensitive to clindamycin• sensitive to chloramphenicol sensitive to chloramphenicol

and tetracyclinesand tetracyclines– resistant cases or resistant cases or

meningitis?meningitis?

Time after start of treatment(days)

Day 0 Day 5 Day 10 Day 15P

ositi

ve T

A c

ultu

re (%

)

0

20

40

60

80

100

Baier RJ et al 2003

Treatment of Genital Treatment of Genital MycoplasmasMycoplasmas

Mycoplasma hominisMycoplasma hominis• insensitive to macrolidesinsensitive to macrolides

• may be sensitive to gentamicin (not reliable)may be sensitive to gentamicin (not reliable)

• sensitive to clindamycinsensitive to clindamycin

• sensitive to chloramphenicol and tetracyclinessensitive to chloramphenicol and tetracyclines

– resistant cases or meningitis?resistant cases or meningitis?

SummarySummary Genital mycoplasmas frequently colonize and Genital mycoplasmas frequently colonize and

infect the respiratory tract of preterm infantsinfect the respiratory tract of preterm infants Infants may develop self limited disease from Infants may develop self limited disease from

infection or may have chronic inflammation that infection or may have chronic inflammation that may predispose to the development of BPDmay predispose to the development of BPD

Identification and treatment of infants with these Identification and treatment of infants with these organisms is frequently delayed or missed organisms is frequently delayed or missed because of specialized culture requirementsbecause of specialized culture requirements

The benefits of treating these infants have not The benefits of treating these infants have not been determined although treatment of infants been determined although treatment of infants with pneumonia or chronic inflammation may be with pneumonia or chronic inflammation may be warrantedwarranted