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TitleMicrobiotec 2011
Tags Antimicrobial Resistance Methicillin Resistant Staphylococcus Aureus Beta Lactamase Senescence
File Size4.0 MB
Total Pages473
Document Text Contents
Page 2
Final electronic edition

Edition: Joana Azeredo, Jorge Pedrosa, Mark Sturme, Nuno Cerca
Cover: Don't Lose Your Brain
Design: Nuno Cerca
Publisher: Universidade do Minho, Departamento de Engenharia Biológica
ISBN: 978-989-97478-2-1

This is the book of abstracts of the scientific presentations at Microbiotec11. The
acceptance of communications was based on the submitted abstracts. The text hereby
reproduced is of the responsibility of its authors.

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Microbiotec11 | Health Microbiology and Biotechnology Posters (PS3)


PS3: 11
The PneumoEL project: epidemiology of pneumococcal colonization
among the elderly
Sónia Almeida1,2, Sónia Nunes1,2, Idalina Valadares3, Sara Martins3, Fátima
Breia4, António Brito-Avô3, Ana Morais3, Hermínia de Lencastre1,5, Raquel Sá-
Leão1, Raquel Sá-Leão2
1Laboratory of Molecular Genetics, ITQB/UNL; 2Laboratory of Molecular Microbiology of Human
Pathogens, ITQB/UNL; 3Agrupamento de Centros de Saúde Oeiras - Carnaxide, Portugal;
4Agrupamento de Centros de Saúde (ACES) do Alentejo Central II, Portugal; 5Laboratory of
Microbiology, The Rockefeller University, New York, USA

Streptococcus pneumoniae (or pneumococcus) is a human commensal that frequently
colonizes the nasopharynx and is a major cause of otitis media, pneumonia,
bacteremia and meningitis worldwide. Risk groups for pneumococcal disease include
children under 5 years old, immunocompromised patients, and the elderly. This
epidemiological pioneer study conducted in Portugal aimed to evaluate pneumococcal
carriage in adults aged over 60 years.Between April and November of 2010, the
nasopharynx (NP) and oropharynx (OP) of adults over 60 years, living in Oeiras (n=
650), an urban area, and in Montemor-o-Novo (n=650), a rural area, were swabbed.
Pneumococci were identified by susceptibility to optochin, solubility in sodium
deoxycholate, and PCR detection of genes cpsA (present in most pneumococci
capsular loci) and lytA (ubiquitous gene in pneumococci that encodes for the major
autolysin) genes. Pneumococcal strains were tested by agar disk diffusion for
susceptibility to chloramphenicol, erythromycin, clindamycin, tetracycline and co-
trimoxazole according to the CLSI guidelines. MICs to ciprofloxacin and penicillin were
determined by E-test. Pneumococcal strains were also serotyped by multiplex PCR
and/or by the Quellung reaction.Of the 1,300 adults swabbed, the mean age was 74
years, (range 60-99 years); 43.8% were male. Most of the participants (91.1%) lived at
home, among which 3.1% lived with children younger than 6 years old. In the rural
area, 17.5% of the participants lived in nursing homes. Chronic respiratory diseases
were reported from c.a. one-fifth (21.8%) of the participants. More than half of the
participants (58.5%) had taken the influenza vaccine in the season, while only a small
percentage (3.5%) had taken the 23-valent pneumococcal polysaccharide vaccine.
Thirty adults (2.3%) carried bona fide

Funded by Laboratórios Pfizer, Lda.

capsulated pneumococci. One adult had two
different pneumococcal strains in the nasopharynx. The 31 strains expressed capsular
types 11A (4 strains), 22F, 23B, and 37 (3 each), 3, 6A, 19A, and 35F (2 each), 5, 9L,
15A, 15B, 16A, 18A, 21, 23A, 31 and 36 (1 each). Four strains were resistant to
macrolides, three were penicillin non-susceptible (0.1 mg/L nd two had
a ciprofloxacin MIC
pneumococcal colonization in adults aged over 60 years in Portugal. The prevalence
of pneumococcal carriage in the elderly is low and large serotype diversity seems to

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Microbiotec11 | Health Microbiology and Biotechnology Posters (PS3)

+'! "

PS3: 14
The effects of allylisothiocyanate and 2-phenylethylisothiocyanate on
biofilm control of pathogenic bacteria
Anabela Portela Borges1,2, Maria José Saavedra1,3, Manuel Simões2
1CECAV-University of Trás-os-Montes e Alto Douro, Vila Real, Portugal, Portugal; 2LEPAE-
Department of Chemical Engineering, Faculty of Engineering, University of Porto, Portugal;

Biofilms are multicellular communities and represent the prevalent mode of microbial
life in nature, industrial processes, and health. It is estimated that biofilms contribute to
more than 80% of all infections in humans. A particular characteristic is their extreme
resistance to antimicrobial treatments. Moreover, the emergence of resistant bacteria
to conventional antimicrobials clearly shows that new biofilm control strategies are
required. Glucosinolates and their hydrolysis products particularly isothiocyanates
have long been accepted for their distinctive benefits to human nutrition and plant
defense. Recent findings indicate that some glucosinolate hydrolysis products (GHP)
have effects against pathogenic bacteria. The purpose of the present study was to
evaluate the activity of two isothiocyanates [allylisothiocyanate (AITC) and 2-
phenylethylisothiocyanate (PEITC)] against biofilms of

Department of Veterinary Sciences, School of Agriculture and Veterinary Science, University of
Trás-os-Montes e Alto Douro, Vila Real, Portugal

Escherichia coli, Pseudomonas
aeruginosa, Staphylococcus aureus and Listeria monocytogenes. Each product was
tested at a concentration of 100, 500 and 1000 µg/ml. The anti-biofouling activities of
AITC and PEITC were tested against the bacteria using a microtiter-plate assay for
biofilm mass quantification (crystal violet staining) and viability activity assessment
(alamar blue staining). The isothiocyanates tested showed a higher potential to reduce
the mass of biofilms formed by the Gram-negative bacteria, comparatively to those
Gram-positive. The highest reduction in biomass was found for strain E. coli and the
smallest was for L. monocytogenes with both isothiocyanates used. No
isothiocyanates showed a total reduction in biofilm formed by the strains in study. In
terms of viability, AITC and PEITC promoted reductions higher than 80% for all the
biofilms tested except for P. aeruginosa

where the biofilm reduction is approximately
70%. AITC and PEITC demonstrated potential to control biofilms of important
pathogenic bacteria. Further studies will be developed in order to assess the effects of
their combination in biofilm control and their mechanisms of antibacterial action.

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Microbiotec11 | Nanotechnology (PS10)

(!+ "

PS10: 6
New sanitization method: synergism between silver nanoparticles and
microwave radiations
Bardia Varastehmoradi1,2, Ahmadreza Shahverdi1
1Tehran University of Medical Sciences, Iran, Islamic Republic of; 2

Different sanitization methods are important aspects in health, especially in
pharmaceutical sciences to decline microbial population .Metal nanoparticles
such as silver nanoparticles can be used to gain this goal as they have
significant antimicrobial effects. Electromagnetic radiations such as
microwave radiations have also power to destroy microorganisms. This
investigation discusses about a new experimental method to kill bacteria by
silver nanoparticles and low frequency of microwave radiations.We
produced silver nanoparticles with biotechnological process that their sizes
are less than 100 nm and average size is 22.5 nm.In this procedure the
supernatant of

Student Scientific
Research Center,Tehran University of Medical Sciences, Islamic Republic of Iran

Klebsiella pneumoniae was added to Silver nitrate at
concentration of 10-3 M and exposed to sunlight.We studied antibacterial
effects against Escherichia coli

with low power of electromagnetic radiation
in a microwave oven (100 watt and 180 watt) in the absence and presence
of sub-inhibitory concentration of silver nanoparticles (10 µg/ml). Colony-
forming unit (CFU) was used for determination of viable cell at different
incubation time.This investigation proved that utilizing of the low frequency
of microwave radiations significantly increased the antimicrobial activity of
silver nanoparticles in just about 10 seconds.The electromagnetic radiation
can damage most of microorganisms. This study described a simple method
to improve antibacterial effects of electromagnetic radiations with sub-
inhibitory concentration of silver nanoparticles. This concentration of silver
nanoparticles (10 µg/ml) was chosen to indicate that the effect observed was
due to the combination and not to the effect of the silver nanoparticles itself
or low frequency of microwave radiation itself. It shows that in just about 10
seconds of radiations, the silver nanoparticles are more toxic than non-
radiated nanoparticles. This method can be used in the most fields of
sciences as a sanitization method for fast killing of microorganisms

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