Molecular investigation of macrolide and Tetracycline

resistances in oral bacteria isolated from Tunisian children

Tarek Zmantar et ál

Steffany Franco SañudoCamilo Díaz Quintero

Medical SchoolMolecular Biology

III SemesterUPB2011

MACROLIDES Are a group of closely related

compounds characterized by a macrocyclic lactone ring to which deoxysugars are attached that have antimicrobial activity

Erythromycin Prototype drug

Katzung Bertram, Farmacología básica y clínica. 11ª ed. Mc graw Hill

Antimicrobial activity

Against gram-positive and negative organisms

Inhibitory Bactericidal

Reducing the protein synthesis

In high concentrations

Acting like

Can Produce

Resistence

Reducing permeability of the

cell membrane

Productionof esterases

Modification of the ribosomal binding site

by

Katzung Bertram, Farmacología básica y clínica. 11ª ed. Mc graw Hill

TETRACYCLINES

Are broad-spectrum bacteriostatic antibiotics that inhibit protein synthesis.

Doxycycline Example drug

Katzung Bertram, Farmacología básica y clínica. 11ª ed. Mc graw Hill

Antimicrobial activity

Against gram-positive and negative organisms

Passive difussion Active process

Reducing the protein synthesis

Acting like

Can Produce Resistence

Decreased intracellular

accumulation

Ribosome protection

Enzymatic inactivation of tetracyclines

by

Inhibitoryby

DRUG RESISTENCEA decrease in sensivity to suficient degree to by reasoneably certain that a strain concerned is different from a sample of wild stains of human type that have never come in contact with the drugs.

A decrease in sensivity to suficient degree to by reasoneably certain that a strain concerned is different from a sample of wild stains of human type that have never come in contact with the drugs.

Katzung Bertram, Farmacología básica y clínica. 11ª ed. Mc graw Hill

SUSCEPTIBILITYAn organism is called

“susceptible” to a drug when the infection caused by it is likely to respond to treatment with this

drug, at the recommended dosage.

An organism is called “susceptible” to a drug when the infection caused by it is likely to respond to treatment with this

drug, at the recommended dosage.

Katzung Bertram, Farmacología básica y clínica. 11ª ed. Mc graw Hill

GENERAL OBJETIVE

Determine the prevalence of antibiotic

susceptibility and the distribution of

erythromycin resistance gene (ermB), the

macrolide efflux (mefI) and tetracycline

resistance genes (tetM, tetO) in oral bacteria

including streptococci and enterococci

isolated from Tunisian children.

Determine the prevalence of antibiotic

susceptibility and the distribution of

erythromycin resistance gene (ermB), the

macrolide efflux (mefI) and tetracycline

resistance genes (tetM, tetO) in oral bacteria

including streptococci and enterococci

isolated from Tunisian children.

PACIENTES

CEPAS• Muestras extraídas de la cavidad oral

de los pacientes

• Se escogieron placas dentales y caries

• Incubadas en medios BHI con sangre

de oveja desfibrinada al 5%

• Se lograron identificar

ESTREPTOCOCOS con tiras de API20

• Se analizaron los resultados con un

mini API

PRUEBAS DE SUSCEPTIBILIDAD

Pruebas de ATB Strep Strip

Es una prueba de susceptibilidad a los antibióticos para el estreptococo que

contiene un rango de 18 tipos diferentes fármacos.

Pruebas de ATB Strep Strip

Es una prueba de susceptibilidad a los antibióticos para el estreptococo que

contiene un rango de 18 tipos diferentes fármacos.

DETECTION DE GENOTIPOS DE RESISTENCIA POR PCR

CARACTERIZACIÓN BIOQUÍMICA

• Se aislaron e identificaron 109 cepas por API 20

• Más aislada Streptococcus mutans

• Se identificaron 15 cepas relacionadas con la aparición de caries

SUSCEPTIBILIDAD ANTIBIÓTICA

De las 109 cepas aisladas se identificó

resistencia a la estreptomicina en un 22% correspondiente

a 24 cepas.

De las 109 cepas aisladas se identificó

resistencia a la estreptomicina en un 22% correspondiente

a 24 cepas.

SUSCEPTIBILIDAD ANTIBIÓTICA

La susceptibilidad intermedia fue del

96.3% para la Kanamicina y la

Gentamicina.

La susceptibilidad intermedia fue del

96.3% para la Kanamicina y la

Gentamicina.

Todas las cepas fueron susceptibles para la

Ampicilina Enterococcus, Telitromicina y Teicoplanina.

Todas las cepas fueron susceptibles para la

Ampicilina Enterococcus, Telitromicina y Teicoplanina.

SUSCEPTIBILIDAD ANTIBIÓTICA

DETECCIÓN DE LOS GENES DE RESISTENCIA POR PCR

Electroforesis en gel de agarosa de PCR multiple amplificando los genes ermB (639 pb) y mefI (263 pb).

DETECCIÓN DE LOS GENES DE RESISTENCIA POR PCR

Electroforesis en gel de agarosa de PCR convencional amplificando el gen tetM (1862 pb).

Electroforesis en gel de agarosa de PCR convencional amplificando gen tetO (538 pb).

DETECCIÓN DE LOS GENES DE RESISTENCIA POR PCR

Author Plot Agree or

Disagree

Warren JJ et ál.

Dental caries is closely associated with mutans streptococci colonizing the oral cavity.

Villedieu A et ál.

Tetracycline-resistant streptococciare frequently isolated from the oral cavity of humans

Author Plot Agree or

Disagree

Martel A et ál.

Acquired resistance against these antibiotics has frequently been described in enterococci.

Lockhart PB et ál.

The failure of antibiotic prophylaxis in dental practice is the major cause of bacteremia after dental procedures. The ability of antibiotic therapy to reduce the frequency of bacteremia associated with dental procedure is controversial

• This investigation can be applied to the daily

procedures because it’s relevant to prevent sistemics

infections.

• The study demostrate the importance of pair differents

subjects such as dentistry, genetic and medicine all for

the patient wellbeing.

• Cariogenic diet and oral hygiene is crucial for the

contribution of the non-development of caries, also the

failure of antibiotic prophylaxis in dental practice is the

major cause of bacteremia after dental procedures.

• Isolated strains showed antibiotic susceptibility of

tetracycline that can be detected by PCR of resistence

genes has frequently been described in

enterococci.

Camilo Andrés Díaz Quintero

Steffany Franco Sañudo