Epidemiología de bacterias anaerobias aisladas en muestras clínicas en el hospital san juan de dios, San José, Costa Rica, durante el trienio 2014, 2015 y 2016 / Epidemiology of anaerobic bacteria isolated in clinical samples at San Juan de Dios Hospital, San José, Costa Rica, during the 2014, 2015 and 2016 triennium

Resumen La epidemiología de las posibles poblaciones en riesgo de sufrir una infección por bacterias anaerobias a nivel nacional es desconocida, se debería de incentivar el conocimiento en los servicios de salud sobre este tipo de infecciones. Las bacterias anaerobias están relacionadas en los medios hospitalarios como causa importante de morbilidad, razón por la cual es conveniente conocer la epidemiologia y prevalecía de especies involucradas. En el Laboratorio de Bacteriología del Hospital San Juan de Dios, durante tres años, se analizaron un total de 1545 pacientes sospechosos de microorganismos anaerobios en medios prerreducidos, mediante un tamizaje se redujeron a un total de 469 posibles muestras, las cuales, fueron enviadas al Laboratorio de Investigación en Bacteriología Anaerobia (LIBA) para su correspondiente identificación. A lo largo de las semanas epidemiológicas de los tres años se encontraron en promedio de 1.77 casos confirmados / semana, con razón de sexo positiva a favor de los masculinos. Se determinó que solo 245 de las muestras enviadas presentaban uno o varios microorganismos anaerobios estrictos representando un 15.85% del total, identificándose 39 especies diferentes, en 306 cepas aisladas. Las mayormente importante fue el género Bacteriodes, provenientes de cavidad abdominal seguido de abscesos y heridas de piel. El presente estudio tiene como objetivo presentar datos que respalden la importancia clínica de la búsqueda de microorganismos anaerobios y que ayuden a los analistas de bacteriología a guiar cuales son los principales microorganismos esperables en muestras clínicas, además de conocer la prevalencia en general.

Abstract The epidemiology of the possible populations at risk of suffering an infection by anaerobic bacteria a national level is unknown, it should be encouraged the knowledge in the health services about this type of infections. Anaerobic bacteria are related in hospital environments as an important cause of morbidity, which is why it is convenient to know the epidemiology and prevalence of species involved. In the Bacteriology Laboratory of the Hospital San Juan de Dios, for three years, a total of 1545 patients suspected of anaerobic microorganisms in prereduced media were analyzed, through a screening was reduced to a total of 469 possible samples, which were sent to the Anaerobic Bacteriology Research Laboratory (LIBA) for its corresponding identification. Throughout the epidemiological weeks of the three years were found on average of 1.77 confirmed cases / week, with a positive sex ratio in favor of men. It was determined that only 245 of the samples sent had one or several strict anaerobic microorganisms representing 15.85% of the total, identifying 39 different species, in 306 isolated strains. The most important was the genus Bacteriodes, coming from the abdominal cavity followed by abscesses and skin wounds. The present study aims to present data that support the clinical importance of the search for anaerobic microorganisms and that help the analysts of bacteriology to guide which are the main expected microorganisms in clinical samples, in addition to knowing the prevalence in general.

Matrix Assisted Laser Desorption/Ionization Time of Flight Mass Spectrometry for identification of Clostridium species isolated from Saudi Arabia

Abstract The aim of this study was to identify different Clostridium spp. isolated from currency notes from the Ha’il region of Saudi Arabia in September 2014 using MALDI–TOF-MS. Clostridium spp. were identified by Bruker MALDI–TOF-MS and compared with VITEK 2. The confirmation of the presence of different Clostridium spp. was performed by determining the sequence of the 16S ribosomal RNA gene. In this study, 144 Clostridium spp. were isolated. Among these specimens, MALDI–TOF-MS could identify 88.8% (128/144) of the isolates to the species level and 92.3% (133/144) to the genus level, whereas, VITEK 2 identified 77.7% of the (112/144) isolates. The correct identification of the 144 isolates was performed by sequence analysis of the 500 bp 16S rRNA gene. The most common Clostridium spp. identified were Clostridium perfringens (67.36%), Clostridium subterminale (14.58%), Clostridium sordellii (9%) and Clostridium sporogenes (9%). The results of this study demonstrate that MALDI–TOF-MS is a rapid, accurate and user friendly technique for the identification of Clostridium spp. Additionally, MALDI–TOF-MS has advantages over VITEK 2 in the identification of fastidious micro-organisms, such as Clostridium spp. Incorporating this technique into routine microbiology would lead to more successful and rapid identification of pathogenic and difficult to identify micro-organisms.

Development of an immunodetection test for a botulinum-like neurotoxin produced by Clostridium sp. RKD.

BACKGROUND & OBJECTIVES: Clostridial neurotoxins are among the most toxic substances known and cause severe illnesses in both humans and animals. A neurotoxigenic Clostridium sp. (strain RKD) isolated from intestine of decaying fish produced a novel, botulinum type B like neurotoxin as suggested by mouse bioassay, protection with anti-botulinum antibodies and PCR. The aim of the present investigation was to develop a laboratory based detection assay as an alternative to the mouse bioassay without compromising sensitivity and specificity. METHODS: Growth and toxin production were carried out in trypticase peptone yeast-extract glucose (TPYG) broth. Toxicity was estimated in terms of minimum lethal dose (MLD) by mouse bioassay. The toxin was partially purified by acid precipitation. It was used for toxoid preparation by formaldehyde treatment. This purified IgG was used for detection of neurotoxin using indirect ELISA. The culture supernatant was concentrated using a stirred cell with a 50 kDa cut-off membrane at 4 degrees C. Further purification was carried out using Prep cell. Fractions showing toxicity and sufficient purity were pooled, concentrated and analyzed on sodium dodecyl sulphatepolyacrylamide gel electrophoresis (SDS-PAGE). RESULTS: The toxin was purified with a recovery of 8.56 per cent. Polyclonal antiserum was raised in mice using partially purified toxin with a titre of 1: 80000. A detection assay with sensitivity of approximately 15 and 300 ng/ml for partially purified and crude toxins, respectively were achieved using an indirect ELISA method. INTERPRETATION & CONCLUSION: The Clostridium sp. RKD produced a potent neurotoxin earlier shown to have novelties. A specific detection assay for the neurotoxin has been developed that may be useful both from food safety and clinical point of view.