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1.
Microb Pathog ; 174: 105859, 2023 Jan.
Article in English | MEDLINE | ID: mdl-36403712

ABSTRACT

Biofilms are responsible for up to 80% of antimicrobial-resistant nosocomial infections. Most of these infections are associated with medical devices such as urinary catheters, and in this context, it is estimated that 90-100% of patients who undergo long-term catheterization develop infections. Proteus mirabilis, the most prevalent microorganism, is responsible for 20-45% of these infections. Thus, this study aimed to evaluate, for the first time, the antimicrobial and antibiofilm effects of cationic porphyrins on P. mirabilis. Neutral porphyrins 3-H2TPyP and 4-H2TpyP and tetra-cationic derivatives 3-cis-PtTPyP and 4-cis-PtTPyP were evaluated in broth microdilution tests to determine the minimum inhibitory and bactericidal concentrations. Time-kill curves, checkerboard test, reactive oxygen species (ROS) scavenger assays, conventional biofilm formation, and biofilm assay with catheters were also performed. The microdilution tests showed greater efficacy against P. mirabilis when 3-cis-PtTPyP was exposed to white-light conditions; this also occurred when the microbial time-kill curve was performed at 0, 2, 6, and 12 h. The radical superoxide species was possibly responsible for photoinactivation in the ROS scavenger assays. In biofilm assays (conventional and catheter), 3-cis-PtTPyP obtained better results when irradiated with a white-light source. In the checkerboard assay, the same compound showed no differences when tested in association with ciprofloxacin hydrochloride. Our findings lead us to conclude that antimicrobial photodynamic therapy and cationic porphyrins obtained positive results and are promising alternatives to treat P. mirabilis biofilms.


Subject(s)
Photochemotherapy , Porphyrins , Humans , Proteus mirabilis , Cisplatin/pharmacology , Reactive Oxygen Species/pharmacology , Anti-Bacterial Agents/pharmacology , Biofilms , Porphyrins/pharmacology
2.
Photodiagnosis Photodyn Ther ; 31: 101920, 2020 Sep.
Article in English | MEDLINE | ID: mdl-32693167

ABSTRACT

In this work, we report the antimicrobial photoinactivation using tetra-cationic porphyrins with peripheral palladium(II) complexes against bacterial strains. Two different isomeric Pd(II)-porphyrins were used and applied in PDI experiments in the strains Gram negative bacilli Escherichia coli, Klebsiella pneumoniae and Pseudomonas aeruginosa and a Gram positive cocci Staphylococcus aureus. All experiments are conducted with adequate concentration (without aggregation) of photosensitizer under white-light irradiation over 2 h . We showed that the most effective PS caused a significative reduction in the concentration of viable bacteria. The present results show that porphyrin with positively charge at meta position (3-PtTPyP) are more efficient photosensitizer against bacteria strains. In this way, tetra-cationic porphyrins might be promising antibacterial PDI agents with potential applications in clinical cases.


Subject(s)
Anti-Infective Agents , Photochemotherapy , Porphyrins , Anti-Bacterial Agents/pharmacology , Photochemotherapy/methods , Photosensitizing Agents/pharmacology , Porphyrins/pharmacology
3.
Anal Chem ; 92(8): 5682-5687, 2020 04 21.
Article in English | MEDLINE | ID: mdl-32207608

ABSTRACT

A simple, rapid, low-cost method was proposed for the imaging of Pseudomonas aeruginosa biofilms on metallic surfaces using an infrared camera. Stainless steel coupons were cooled to generate a thermal gradient in relation to biofilm for active thermography (AT). Both cooling and image acquisition times were optimized and the images obtained with AT were compared with those from scanning electron microscopy. A free software (Thermofilm) was developed for image processing and the results were compared with the software ImageJ, with good agreement (from 87.7 to 103.8%). Images of coupons treated with sanitizer (peracetic acid) were obtained to show the applicability of the proposed method for biofilm studies. All analytical steps could be performed in 3 min in a noncontact, nondestructive, low-cost, portable, and easy-to-use way.


Subject(s)
Stainless Steel/chemistry , Thermography , Anti-Bacterial Agents/pharmacology , Biofilms/drug effects , Food Microbiology , Microbial Sensitivity Tests , Peracetic Acid/pharmacology , Pseudomonas aeruginosa/drug effects , Surface Properties
4.
Rev. epidemiol. controle infecç ; 9(2): 177-184, 2019. ilus
Article in Portuguese | LILACS | ID: biblio-1021941

ABSTRACT

Justificativa e Objetivos: Sabe-se que a sífilis adquirida, no cenário epidemiológico gaúcho, configura-se como doença de extrema importância devido a sua alta prevalência e ascensão. A partir disso, o seguinte trabalho visa revisar as medidas utilizadas na assistência dos pacientes adultos e idosos com diagnóstico de sífilis adquirida e sua epidemiologia no município de Porto Alegre/RS. Conteúdo: Segundo dados publicados em 2016 pelo Ministério da Saúde, o crescimento da infecção por sífilis em indivíduos adultos e idosos está em grande expansão no Brasil. Através das conquistas pelos idosos nas últimas décadas, o prolongamento da vida sexual é ponto merecedor de destaque, além do incentivo à socialização e a falta de informação sobre saúde sexual. Conclusão: As infecções sexualmente transmissíveis crescem nestes dois públicos e necessita-se medidas preventivas mais efetivas no âmbito da saúde pública.(AU)


Background and Objectives: It is known that acquired syphilis, in the "gaúcho" epidemiological scenario, is a disease of extreme importance due to its high prevalence and rise. From this, the following work aims to review the measures used in the care of adult and elderly patients diagnosed with acquired syphilis and its epidemiology in the city of Porto Alegre / RS. Contents: According to data published in 2016 by the Ministry of Health, the growth of syphilis infection in adults and elderly individuals is in great expansion in Brazil. Through the achievements of the elderly in the last decades, the prolongation of sexual life is a point worth highlighting, besides the incentive to socialization and the lack of information on sexual health. Conclusion: Sexually transmitted infections grow in these two publics and more effective preventive measures in the field of public health are needed.(AU)


Justificación y Objetivos: Se sabe que la sífilis adquirida, en el escenario epidemiológico"gaúcho", se configura como una enfermedad de extrema importancia debido a su alta prevalencia y ascenso. A partir de ello, el siguiente trabajo busca revisar las medidas utilizadas en la asistencia de los pacientes adultos y ancianos con diagnóstico de sífilis adquirida y su epidemiología en la ciudad de Porto Alegre / RS. Contenido: Según datos publicados en 2016 por el Ministerio de Salud, el crecimiento de la infección por sífilis en individuos adultos y ancianos está en gran expansión en Brasil. A través de los logros alcanzados por los ancianos en las últimas décadas, la prolongación de la vida sexual es un punto merecedor de hincapié, además del incentivo a la socialización y la falta de información sobre salud sexual. Conclusiones: Las infecciones sexualmente transmisibles crecen en estos dos públicos y se necesitan medidas preventivas más efectivas en el ámbito de la salud pública.(AU)


Subject(s)
Humans , Adult , Middle Aged , Aged , Aged, 80 and over , Aged , Syphilis , Epidemiology , Communicable Diseases , Adult , Public Health
5.
Microb Pathog ; 113: 432-437, 2017 Dec.
Article in English | MEDLINE | ID: mdl-29162482

ABSTRACT

Microbial biofilms represent a challenge in the treatment of infections, due to the low efficacy of the antimicrobials. This study evaluated the antimicrobial effect of nanoparticles of Melaleuca alternifolia (TTO) in dental biofilm. Thirty-eight volunteers used an oral device in situ in situ including four bovine enamel specimens for 07 days. From the fifth day four solutions were applied randomly for each specimen: Physiological Saline Solution (0.85% NaCl) (C+), Chlorhexidine 0.12% (CHX), M. alternifolia oil 0.3% (TTO), and a nanoparticle solution of 0.3% M. alternifolia oil (NPTTO). The nanoparticles of TTO were characterized for pH, IPD, medium size, zeta potential and Transmission Electron Microscopy. Antimicrobial activity was evaluated by viable microorganisms count and the structure of the biofilm by atomic force microscopy. The NPTTO presented pH 6.4, particle diameter of 197.9 ± 1 nm, polydispersion index of 0.242 ± 0.005, zeta potential of -7.12 mV and ±0:27 spherical shape. The C+ resulted in 100% of bacterial vitality, while CHX, TTO and NPTTO showed 34.2%, 51.4% and 25.8%, respectively. The AFM images showed biofilms with an average roughness of 350 nm for C+, 275 nm for CHX, 500 nm for TTO and 100 nm for NPTTO. The NPTTO demonstrated excellent antimicrobial activity in the biofilm formed in situ and will possibly be used in future for the treatment/prevention of oral biofilms.


Subject(s)
Anti-Infective Agents/pharmacology , Biofilms/drug effects , Melaleuca/chemistry , Nanoparticles/chemistry , Plant Exudates/pharmacology , Adult , Animals , Bacteria/drug effects , Bacterial Adhesion/drug effects , Brazil , Cattle , Chlorhexidine/pharmacology , Colony Count, Microbial , Dental Enamel/microbiology , Dental Plaque/drug therapy , Dental Plaque/microbiology , Dental Plaque/prevention & control , Female , Humans , Hydrogen-Ion Concentration , Male , Microbial Sensitivity Tests , Microbial Viability/drug effects , Particle Size , Pilot Projects , Sodium Chloride/pharmacology , Tea Tree Oil/pharmacology , Time Factors , Young Adult
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