Evaluation of Giardia duodenalis viability after metronidazole treatment by flow cytometry

Giardia duodenalis (syn. lamblia; syn. intestinalis) susceptibility testing is not routinely performed because the classical culture methods are very time-consuming and laborious. We developed a novel flow cytometry (FC) assay to evaluate the susceptibility of G. duodenalis trophozoites to metronidazole (MTZ). Different concentrations of MTZ were added to cultures of trophozoites (10 5 /mL) and the cultures were incubated for different periods. The 50% inhibitory concentration was calculated and propidium iodide (PI) was used to quantify the number of dead cells. After treatment, PI-positive trophozoites increased with increasing drug concentration and exposure time. An excellent correlation was found between FC and the classical method. A novel, accurate and reliable method is now available to evaluate G. duodenalis viability. .

Cryptosporidium spp., Giardia lamblia y encephalitozoon intestinalis, oportunistas emergentes / Cryptosporidium spp., Giardia lamblia y encephalitozoon intestinalis emergent opportunists

Es un hecho conocido que las infecciones oportunistas por protozoos y hongos han aumentado en los últimos años, debido especialmente al aumento de las infecciones por VIH. Cryptosporidium spp., Giardia lamblia y Encephalitozoon intestinalis son protozoos y hongo, respectivamente, mundialmente reconocidos como agentes oportunistas emergentes, responsables de brotes epidémicos provocados por la ingestión de agua potable contaminada, incluso después de una correcta desinfección. La ingestión de estos protozoos puede provocar diferentes grados de enfermedad, entre aguda o leve (población sana) hasta situaciones más graves y agresivas, hasta a veces mortales (pacientes inmunocomprometidos y/o inmunodeprimidos). A pesar de ser responsables de muchos brotes epidémicos, su diagnóstico de laboratorio permanece arduo y trabajoso, incluso utilizando las nuevas técnicas desarrolladas en los últimos años. En esta revisión se resumen las consideraciones generales de estos oportunistas emergentes, así como los métodos de diagnóstico más usuales, incluso los más recientes y específicos.

Epidemiological data, regarding parasitic and fungi opportunist infections, have changed in the last years, especially due to HIV infection. Cryptosporidium spp., Giardia lamblia and Encephalitozoon intestinalis are protozoan and fungi, respectively, worldwide known as opportunistic emergent agents, being responsible by epidemic outbreaks after ingestion of contaminated water, even following a correct disinfection treatment. Its ingestion can cause different effects on individuals’ health, from light or acute among the healthy population, to serious, aggressive or even deadly among the immunodepressed or immunocompromised patients. Contaminated water ingestion can result in outbreaks but protozoa laboratory diagnosis still remains very laborious, even after the development of more sensitive and specific techniques in the last years. In this paper, a revision of these emergent opportunists, their main characteristics and diagnostic tools are described, including the most recent and specific techniques.

Preliminary results of the use an ultrasonic equipment in the treatment of moderate periodontitis: clinical and microbiological real time polimerase chain reacion-based (PCR) study

OBJETIVE: This preliminary study aimed to evaluate clinically and microbiologically the treatment of patients with light to moderate periodontal disease by using an ultrasonic device. MATERIAL AND METHODS: Sixteen adults with moderate periodontitis were studied. A Real-time PCR protocol was optimised using specific primers for the three microorganisms. Clinical and microbiological testing was performed prior and following treatment. RESULTS: Despite clinical improvement, bacteria quantification didn’t change. All the patients were positive for P. gingivalis and P. intermedia and nine for A. actinomycetemcomitans. CONCLUSION: VectorTM-system treatment showed clinical improvement. A Real-time PCR protocol is now available for periodontal diagnostics and monitorization. However, further studies with larger populations are indicated.

OBJETIVOS: Este estudo preliminar teve a finalidade de avaliar clinicamente microbiologicamente o tratamento de pacientes portadores de periodontite leve a moderada, utilizando-se um novo aparelho piezo-elétrico disponível no mercado (VectorTM system). MATERIAL E MÉTODO: Dezesseis pacientes adultos, portadores de periodontite leve a moderada, foram submetidos ao tratamento. Utilizou-se um protocolo de PCR em tempo real utilizando primers específicos para três microrganismos. Realizaram-se avaliação clínica e um estudo microbiológico simultâneo antes e após os tratamentos. RESULTADOS: A avaliação clínica foi positiva, embora não tendo ocorrido alterações na quantidade de bactérias. Todos os pacientes apresentaram amplificação específica para P. intermedia e P. gingivalis e nove pacientes para A. Actinomycetemcomitans. CONCLUSÃO: Considerando-se os resultados deste estudo preliminar, tratamento com o aparelho testado mostrou eficácia clínica. O protocolo utilizado neste estudo está agora disponível para diagnóstico periodontal e monitoração de resultados de tratamento. Entretanto, indica-se estudos clínicos e microbiológicos mais aprofundados, com amostras maiores, para conclusões mais consistentes.