Helicobacter pylori: Multiple resistance in patients from Bogotá, Colombia / Helicobacter pylori: resistencia múltiple en pacientes de Bogotá, Colombia

Introduction: The main cause for Helicobacter pylori infection treatment failure is antibiotic resistance, where clarithromycin and metronidazole play the main role. In Colombia, primary resistance as a consequence of the use of these two antibiotics and excessive levofloxacin use is above the accepted limit (13.6%, 83%, and 16%, respectively). Despite this fact, empirical therapies that include the combination of these antibiotics are used in patients with previous therapeutic failure. Objective: To determine antibiotic resistance in patients previously treated for H. pylori in Bogotá, Colombia. Materials and methods: We conducted a descriptive study that included ten isolates obtained from five patients with three or four previous failed treatments for H. pylori. Antibiotic resistance to amoxicillin, clarithromycin, levofloxacin, and metronidazole was investigated by agar dilution and confirmed by DNA sequencing (Magrogen, Korea). Results: Eight isolates were resistant to two or more antibiotics. All isolates were resistant to levofloxacin. Susceptibility patterns in isolates from the gastric antrum and the body of the stomach were different in three patients. Conclusion: As far as we know, this is the first evidence of multiple H. pylori resistance in Colombia in previously treated patients. Results demonstrated the consequences of using an ineffective antibiotic scheme and the need to assess antibiotic susceptibility in different anatomical sites of the stomach. The consequences of multiple resistance decrease possible antibiotic effectiveness to eradicate H. pylori in the future.

Introducción. La resistencia a los antibióticos es la principal causa del fracaso del tratamiento contra Helicobacter pylori; la claritromicina y el metronidazol son los antibióticos que generan mayor resistencia. En Colombia, la resistencia primaria a estos dos antibióticos y el uso excesivo de levofloxacina han alcanzado los límites aceptados (13,6, 83 y 16 %, respectivamente). A pesar de ello, se usa el tratamiento empírico combinando estos antibióticos en pacientes en los que ha fallado anteriormente. Objetivo. Determinar la resistencia a los antibióticos en pacientes previamente tratados para H. pylori en Bogotá, Colombia. Materiales y métodos. Se llevó a cabo un estudio descriptivo en el que se evaluó mediante dilución en agar la resistencia a la amoxicilina, la claritromicina, la levofloxacina y el metronidazol en 10 aislamientos provenientes de 5 pacientes con tres o cuatro tratamientos fallidos para H. pylori. La resistencia a los antibióticos se confirmó mediante secuenciación de ADN (Magrogen, Korea). Resultados. Ocho de los aislamientos presentaron resistencia a dos o más antibióticos y todos fueron resistentes a la levofloxacina. Los patrones de sensibilidad de los aislamientos provenientes del antro pilórico y del cuerpo del estómago, fueron diferentes en tres de los pacientes. Conclusión. Hasta donde se sabe, esta es la primera evidencia de resistencia múltiple de H. pylori en Colombia en pacientes previamente tratados. Los resultados evidenciaron las consecuencias del uso de un esquema ineficaz de tratamiento antibiótico y la necesidad de evaluar la sensibilidad a los antibióticos en diferentes sitios anatómicos del estómago. La resistencia múltiple limita el número de antibióticos útiles para erradicar H. pylori.

Presence and antimicrobial profile of gram-negative facultative anaerobe rods in patients with chronic periodontitis and gingivitis.

Chronic periodontitis is a multifactorial infectious disease associated with Gram-negative anaerobes which are part of the subgingival microflora. In recent years, studies have been conducted to assess the presence of Gram-negative facultative anaerobes (Enterobacteriaceae) and their participation in the development and progression of chronic periodontitis. The aim of this study was to determine the presence of Enterobacteriaceae in patients with chronic periodontitis and gingivitis and to assess antimicrobial susceptibility of clinical isolates. A descriptive, observational study was performed including 64 patients with chronic periodontitis and 22 patients with gingivitis. Microbiological samples were taken from the gingival sulcus using paper points, which then were placed in thioglycollate broth. Samples were incubated for 4 hours at 37 degrees C and finally replated on MacConkey agar Bacteria were identified using the API-20E system (Biomerieux, France) and antimicrobial susceptibility was determined using the disk diffusion method. The evaluation of samples showed presence of 29 enterobacterial species distributed as follows: 7 in the group with gingivitis and 22 in the group with chronic periodontitis. In the chronic periodontitis group the most common species were: K. oxytoca n = 5, S. liquefaciens n = 4 and K. pneumoniae and E. coli with n = 3. The gingivitis group had the highest frequency of Erwinia sp. (n = 2). Clinical isolates showed very low sensitivity levels to beta-lactam ampicillin and amoxicillin/ clavulanic acid, 17.2% and 27.6% respectively, and higher sensitivity levels to ciprofloxacin (96.6%), amikacin (79.3%), gentamicin (68.9%) and ceftazidime, ceftriaxone, kanamycin and trimethoprimsulfa (65.5%). In conclusion, the existence of a high frequency of enterobacteria in patients with chronic periodontitis and gingivitis shows that periodontologists should pay greater attention to prevention protocols, and develop mechanical and antimicrobial therapies in which antimicrobial susceptibility profile reports should be considered as part of periodontal treatment.

Phenotypic and genotypic analysis of clarithromycin-resistant Helicobacter pylori from Bogotá D.C., Colombia.

Resistance of Helicobacter pylori to clarithromycin is the most common cause of treatment failure in patients with H. pylori infections. This study describes the MICs and the presence of 23S rRNA mutations of H. pylori isolates from Bogotá, D.C., Colombia. H. pylori were isolated from gastric biopsies from patients with functional dyspepsia. Clarithromycin susceptibility was investigated by agar dilution and strains were considered resistant if the MIC was ≥ 1 µg/ml. DNA sequences of the 23S rRNA gene of strains resistant and sensitive to clarithromycin were determined to identify specific point mutations. Clarithromycin resistance was present in 13.6% of patients by agar dilution. The A2143G, A2142G and A2142C mutations were found in 90.5, 7.1, and 2.4% of H. pylori strains with resistance genotype.The resistant phenotype was associated with 23S rRNA resistance genotype in 85.7% of isolates. The point mutations in 23S rRNA were well correlated with MICs values for clarithromycin.

Presence and antimicrobial profile of Gram-negative facultative anaerobe rods in patients with chronic periodontitis and gingivitis

La periodontitis crónica es una enfermedad infecciosa multifactorial hacen parte de la microflora subgingival. En los últimos años se han realizado estudios para valorar la presencia de bacilos Gramnegativos anaerobios facultativos (enterobacterias) y suimportancia en el desarrollo y rogresión de la periodontitis crónica. El objetivo de este estudio fue determinar la presencia de enterobacterias en pacientes con periodontitis crónica y gingivitis y conocer la susceptibilidad antimicrobiana de los aislamientosclínicos. Se realizó un estudio observacional y descriptivo en elque se incluyeron 64 pacientes con periodontitis crónica y 22 pacientes con gingivitis. Las muestras tomadas en el surco gingival con conos de papel se depositaron en caldo tioglicolato, seincubaron durante 4 horas a 37 oC y se resembraron finalmente en Agar MacConkey. En la identificación de las bacterias se utilizó el sistema API-20E (Biomerieux, France) y la susceptibilidadantimicrobiana se realizó por el método de difusión en disco. En los dos grupos se identificaron 29 especies enterobacterianas, 7 en el grupo con gingivitis y 22 en el grupo con periodontitis crónica. En el grupo de periodontitis crónica las especies masfrecuentes fueron: K. oxytoca n=5, S. liquefaciens n=4 y K.pneumoniaey E. coli con n=3. En el grupo con gingivitis, Erwiniasp tuvo la mayor frecuencia (n=2). Los aislamientos clínicos presentaron níveles muy bajos de sensibilidad a los B-lactamicosampicilina y amoxicilina/ ac.clavulanico, 17.2 y 27.6 por ciento, y la mayor sensibilidad a ciprofloxacina. En conclusión, la alta frecuencia de enterobacterias en pacientes con periodontitis debe conducir a la prevención y a desarrollar terapias mecánicas y antimicrobianas en las cuales se tengan en cuenta, como parte del tratamiento periodontal, los perfiles antimicrobianos reportados.

Presence and antimicrobial profile of gram-negative facultative anaerobe rods in patients with chronic periodontitis and gingivitis. / Presence and antimicrobial profile of gram-negative facultative anaerobe rods in patients with chronic periodontitis and gingivitis.

Chronic periodontitis is a multifactorial infectious disease associated with Gram-negative anaerobes which are part of the subgingival microflora. In recent years, studies have been conducted to assess the presence of Gram-negative facultative anaerobes (Enterobacteriaceae) and their participation in the development and progression of chronic periodontitis. The aim of this study was to determine the presence of Enterobacteriaceae in patients with chronic periodontitis and gingivitis and to assess antimicrobial susceptibility of clinical isolates. A descriptive, observational study was performed including 64 patients with chronic periodontitis and 22 patients with gingivitis. Microbiological samples were taken from the gingival sulcus using paper points, which then were placed in thioglycollate broth. Samples were incubated for 4 hours at 37 degrees C and finally replated on MacConkey agar Bacteria were identified using the API-20E system (Biomerieux, France) and antimicrobial susceptibility was determined using the disk diffusion method. The evaluation of samples showed presence of 29 enterobacterial species distributed as follows: 7 in the group with gingivitis and 22 in the group with chronic periodontitis. In the chronic periodontitis group the most common species were: K. oxytoca n = 5, S. liquefaciens n = 4 and K. pneumoniae and E. coli with n = 3. The gingivitis group had the highest frequency of Erwinia sp. (n = 2). Clinical isolates showed very low sensitivity levels to beta-lactam ampicillin and amoxicillin/ clavulanic acid, 17.2

and 27.6

respectively, and higher sensitivity levels to ciprofloxacin (96.6

), amikacin (79.3

), gentamicin (68.9

) and ceftazidime, ceftriaxone, kanamycin and trimethoprimsulfa (65.5

). In conclusion, the existence of a high frequency of enterobacteria in patients with chronic periodontitis and gingivitis shows that periodontologists should pay greater attention to prevention protocols, and develop mechanical and antimicrobial therapies in which antimicrobial susceptibility profile reports should be considered as part of periodontal treatment.

Presence and antimicrobial profile of Gram-negative facultative anaerobe rods in patients with chronic periodontitis and gingivitis

La periodontitis crónica es una enfermedad infecciosa multifactorial hacen parte de la microflora subgingival. En los últimos años se han realizado estudios para valorar la presencia de bacilos Gramnegativos anaerobios facultativos (enterobacterias) y suimportancia en el desarrollo y rogresión de la periodontitis crónica. El objetivo de este estudio fue determinar la presencia de enterobacterias en pacientes con periodontitis crónica y gingivitis y conocer la susceptibilidad antimicrobiana de los aislamientosclínicos. Se realizó un estudio observacional y descriptivo en elque se incluyeron 64 pacientes con periodontitis crónica y 22 pacientes con gingivitis. Las muestras tomadas en el surco gingival con conos de papel se depositaron en caldo tioglicolato, seincubaron durante 4 horas a 37 oC y se resembraron finalmente en Agar MacConkey. En la identificación de las bacterias se utilizó el sistema API-20E (Biomerieux, France) y la susceptibilidadantimicrobiana se realizó por el método de difusión en disco. En los dos grupos se identificaron 29 especies enterobacterianas, 7 en el grupo con gingivitis y 22 en el grupo con periodontitis crónica. En el grupo de periodontitis crónica las especies masfrecuentes fueron: K. oxytoca n=5, S. liquefaciens n=4 y K.pneumoniaey E. coli con n=3. En el grupo con gingivitis, Erwiniasp tuvo la mayor frecuencia (n=2). Los aislamientos clínicos presentaron níveles muy bajos de sensibilidad a los B-lactamicosampicilina y amoxicilina/ ac.clavulanico, 17.2 y 27.6 por ciento, y la mayor sensibilidad a ciprofloxacina. En conclusión, la alta frecuencia de enterobacterias en pacientes con periodontitis debe conducir a la prevención y a desarrollar terapias mecánicas y antimicrobianas en las cuales se tengan en cuenta, como parte del tratamiento periodontal, los perfiles antimicrobianos reportados.(AU)

Importancia de la proteína CagA en infección por Helicobacter pylori / The importance of CagA protein in Helicobacter Pylori infection

Helicobacter pylori es una bacteria que tiene la capacidad de colonizar la mucosa gástrica de humanos y producir gastritis crónica y otras complicaciones. Está presente en 20-50% de la población en países industrializados y en el 80% o más en los países subdesarrollados. Es un microorganismo genéticamente variable, cuya mayor plasticidad genética se encuentra en un segmento de DNA de 40kb conocido como islote de patogenicidad (PAI), el cual codifica para la proteína CagA y para los componentes del sistema de secreción tipo IV, este último encargado de permitir la exportación de esta proteína al interior de la célula blanco. El gen cagA codifica la proteína CagA, cuya presencia es indicador de la isla de patogenicidad y de características patógenas de las cepas del microorganismo; con base en cag A, las cepas se clasifican como cagA+ y cagA- , siendo las primeras más virulentas que las segundas. La importancia de las cepas cagA+ es la evidencia de su relación con el desarrollo de cáncer gástrico. En la presente revisión se analiza el papel de los genes del islote de patogenicidad y su asociación con el desarrollo de patologías gastroduodenales.

Helicobacter pylori is a microorganism able to colonize gastric mucosa in humans where it can produce chronic gastritis and other type of complications. H. pylori is present approximately 20-50% in the industrialized countries but in developing countries its prevalence is the highest because approximately 80% of people are infected with the bacteria. In general this bacteria is variable in its genome but the greatest genetic plasticity is located at 40kb DNA segment, knowing as a pathogenicity island (PAI), inside of this DNA segment there are cagA gen which coding for CagA protein and genes that coding for type IV secretion system that is necessary for export CagA protein into target cell. cagA gen is important because it is a marker of PAI presence and because the presence of cagA has permitted classified H. pylori strains in cagA+ and cagA-, which is of great importance due cagA+ strains are more virulent than cagA- strains, although the principal importance of cagA + strains is its special association with gastric cancer. The aim of this review is study the functions of pathogenicity island genes and its association with gastro duodenal pathologies developing.

Antagonistic action of indigenous Streptococcus mutans strains.

Dental caries is an infectious process which ultimately destroys the tooth. Streptococcus mutans is considered to be the main agent causing this disease. If microorganisms with antagonistic action on S. mutans were found, they might provide a way of avoiding or controlling the disease. Within the framework of the Oral Microbial Ecology approach, the aim of this project was to identify S. mutans strains with antagonistic effect upon S. mutans. Saliva samples were taken from 66 children and cultured on Blood agar and Mitis Salivarius Bacitracin agar. They were incubated at 37 degrees C in anaerobic atmosphere for 48 hours, after which bacteria were counted and biochemical tests performed on colonies compatible with S. mutans. Antagonistic effect was determined using the double layer in agar technique. In children without and with caries, the frequency of S. mutans was 91.7% and 96.7%, respectively. In the group of patients without caries, only two strains had no antagonistic action, and three strains had full antagonistic action (100%), while the rest showed different kinds of inhibitory action. In the group of patients with caries, only 5 strains had no antagonistic action, 32 strains had full antagonistic action (100%) and the rest had variable inhibitory action. To conclude, 112 S. mutans strains with high antagonistic potential were identified, which, after other requirements are fulfilled, could be used in caries prevention or control strategies.

Antagonistic action of indigenous Streptococcus mutans strains

Dental caries is an infectious process which ultimately destroys the tooth. Streptococcus mutans is considered to be the main agent causing this disease. If microorganisms with antagonistic action on S. mutans were found, they might provide a way of avoiding or controlling the disease. Within the framework of the Oral Microbial Ecology approach, the aim of this project was to identify S. mutans strains with antagonistic effect upon S. mutans. Saliva samples were taken from 66 children and cultured on Blood agar and Mitis Salivarius Bacitracin agar. They were incubated at 37oC in anaerobic atmosphere for 48 hours, after which bacteria were counted and biochemical tests performed on colonies compatible with S. mutans. Antagonistic effect was determined using the double layer in agar technique. In children without and with caries, the frequency of S. mutans was 91.7% and 96.7%, respectively. In the group of patients without caries, only two strains had no antagonistic action, and three strains had full antagonistic action (100%), while the rest showed different kinds of inhibitory action. In the group of patients with caries, only 5 strains had no antagonistic action, 32 strains had full antagonistic action (100%) and the rest had variable inhibitory action. To conclude, 112 S. mutans strains with high antagonistic potential were identified, which, after other requirements are fulfilled, could be used in caries prevention or control strategies.

La caries dental es un proceso infeccioso que termina en la destruccion del diente. Streptococcus mutans es considerado el principal agente causal de esta enfermedad. La busqueda de microorganismos con accion antagonica sobre S. mutans puede ser una alternativa con la cual se pueda evitar o controlar esta enfermedad. Este proyecto enmarcado dentro de la linea de Ecologia Microbiana Oral, tuvo como objetivo identificar cepas S. mutans con efecto antagonico. Se tomaron muestras de saliva en 66 ninos y se cultivaron en Agar Sangre y Agar Mitis Salivarius Bacitracina. Despues de la incubacion a 37oC en anaerobiosis durante 48 horas, se hizo el recuento bacteriano y las colonias compatibles con S. mutans fueron sometidas a pruebas bioquimicas. La determinacion del efecto antagonico se realizo utilizando la tecnica de doble capa en agar. En los ninos sin caries y con caries la frecuencia de S. mutans fue, respectivamente, 91.7% y 96.7%. En el grupo de pacientes sin caries solo dos cepas no tuvieron ninguna accion antagonica, tres cepas tuvieron accion antagonica completa (100%), y las restantes presentaron diferentes modalidades de inhibicion. En el grupo de pacientes con caries solo 5 cepas no tuvieron ninguna accion antagonica, 32 cepas tuvieron accion antagonica completa (100%) y las demas cepas tuvieron actividad inhibitoria variable. En conclusion, se identificaron 112 cepas S. mutans con gran potencial antagonico, las cuales despues de cumplir con otros requerimientos podrian ser utilizadas en estrategias de prevencion o control de la caries dental.