Propiedades probióticas de Lactobacillus spp aislados de biopsias gástricas de pacientes con y sin infección por Helicobacter pylori / Probiotic properties of Lactobacillus spp isolated from gastric biopsies of Helicobacter pylori infected and non-infected individuals

Background: Gastric microbiota is a complex ecosystem, composed by diverse microorganisms, where H pylori and Lactobacillus are relevant species. Aim: To study the probiotic properties of Lactobacillus spp isolated from gastric biopsies of subjects bearing or not H pylori. Materials and Methods: Gastric biopsies from 197 individuals that consulted for gastrointestinal disorders were cultivated in media specific for H pylori and Lactobacillus spp. Probiotic properties of lactobacilli isolates and histological diagnosis of H pylori colonized patients were performed. Results: Among 197 individuals evaluated, Hpylori was detected in 43 percent, Lactobacillus spp in 24 percent, while 8 percent presented both bacteria simultaneously. Forty one percent of the Lactobacillus spp strains produced hydrogen peroxide, S'3 percent presented a highly hydrophobic surface and 32 percent had an inhibitory effect upon Hpylori ATCC 43504, even greater than Lactobacillus LGG or LAL reference strains. The main pathological diagnosis of patients ivas chronic non-atrophic gastritis (73 percent) followed by intestinal metaplasia (19 percent). A similar proportion of both conditions were observed in patients colonized by Lactobacillus spp, while not colonized individuals developed preferentially chronic non-atrophic gastritis (p =0.002). Conclusions: Lactobacillus spp and H pylori were mutually excluded, suggesting a competitive colonization model between probiotic bacteria and pathogens.

Detección de Helicobacter pylori en mucosa gástrica y cavidad oral / Helicobacter pylori detection in gastric and oral mucosa

Helicobacter pylori (H pylori) infection has been related to various gastroduodenal disorders. The objective of this study was to detect H pylori in gastric mucosa and relate it to its presence in the oral cavity. Fifty-four patients with medical indication oi digestive endoscopy from the Gastroenterology Unit of the Regional Hospital of Concepción, Chile, were studied. Gastric samples were obtained from each patient from antrum and corpus through endoscopic biopsies. Oral samples were obtained from dental plaque and saliva swabs from the floor of the mouth and the base of the tongue. Oral and gastric sample were studied by culture. Oral samples from patients with positive gastric cultures for H pylori (n = 21) were studied by culture, conventional PCR and Real Time PCR. Ail cultures from oral samples were negative (0/21) for H pylori. Only one sample of dental plaque was positive with conventional PCR (1/21), while ail samples of saliva were negative. However, samples from ail patients were positive with Real Time PCR (20/21 dental plaque, 21/21 saliva from the floor of the mouth, 20/21 saliva from the base of the tongue). The results suggest that there is a correlation between the presence of H pylori in gastric mucosa and the oral cavity. Also, that Real Time PCR the best technique to detect low number of bacteria in the oral cavity.

La infección por Helicobacter pylori está vinculada a diversas patologías gastroduo-denales. El objetivo de este estudio fue detectar H. pylori en la mucosa gástrica y relacionar su presencia con H. pylori en la cavidad oral. Se estudiaron 54 pacientes de la Unidad de Gastroenterología del Hospital Regional de Concepción, con indicación de endoscopía digestiva alta. Para cada paciente se realizó biopsia de mucosa gástrica (antro y cuerpo), y se obtuvieron 3 muestras orales (placa bacteriana, saliva de la base de la lengua y piso de boca). Las muestras gástricas y orales fueron cultivadas. Las muestras orales de los pacientes que presentaron cultivos de biopsia gástrica positivos para H. pylori (n = 21) fueron sometidas a análisis de detección de la bacteria mediante cultivo, PCR convencional y PCR de Tiempo Real. Los resultados obtenidos para las muestras orales fueron: cultivo 100 por ciento negativos (0/21), con PCR convencional se detectó H. pylori sólo en un paciente (una muestra de las 3 en placa bacteriana) (1/21), mientras que todas las muestras de saliva de piso de boca y base de la lengua fueron negativas. Veintiún pacientes resultaron positivos para la bacteria por la técnica de PCR de Tiempo Real en las muestras orales, 20/21 en muestras de placa bacteriana, 21/21 en saliva de piso de boca y 20/21 en base de lengua. Los resultados sugieren que existe correlación entre la presencia de H. pylori en la mucosa gástrica y en la cavidad oral. Además, que la técnica de PCR de Tiempo Real es la más adecuada para detectar el bajo número de bacterias de H. pylori de la cavidad oral.

Genotipificación de aislados clínicos de Helicobacter pylori en base a genes asociados a virulencia cagA, vacA y babA2: Primer aislamiento de una cepa babA2 positiva en pacientes chilenos / Genotypying of clinical isolates of Helicobacter pylori by cagA, vacA and babA2 virulence associated genes: First detection of a babA2 positive strain in Chilean patients

Background: Helicobacter pylori-associated gastroduodenal diseases depends on host characteristics, environmental conditions and bacterial virulence factors, such as cagA, vacA y babA2 gene products. Moreover, peptic ulcer disease has been related with cagA+, vacAs1m1 strains, while metaplasia and gastric cancer has been associated to cagA+, vacAs1 and babA2+ H pylori strains. Gene babA2 has not yet been described in clinical isolates from Chilean patients. Aim: To investigate the presence of cagA, vacA (s and m) and babA2 genes in clinical isolates of H pylori from Chilean patients. Material and Methods: Sixty six isolates from 41 patients were genotyped by PCR, using primers for s1a, s1b, s2, m1, m2, cagA and babA2 genes as previously described. Results: cagA gene was detected in 16 isolates (24.2 percent) while vacAs1a, vacAs1b, vacAs2, vacAm1 and vacAm2 were detected in 28 (42.4 percent), 14 (21.2 percent), 17 (25.8 percent), 21 (31.8 percent) and 29 isolates (43.9 percent), respectively. One isolate (1.5 percent) was babA2 positive, being the first isolate with this genotype described in Chile. Besides the babA2+ genotype this clinical isolate also presented cagA+ and vacAs1a which has been related with metaplasia or gastric cancer. Five isolates showed an ulcerogenic profile cagA+, vacAs1m1. Conclusions: The results presented indicate the prevalence of vacAs1m1 genotype among the clinical isolates analyzed, and a low frequency of babA2 genotype.

Embarazo en la adolescencia y su relación con la deserción escolar / The relationship between teenage pregnancy and school desertion

Background: In Chile, the prevalence of teenage pregnancy is 17 percent. Aim: To assess relationship between adolescent pregnancy and school desertion. Patients and methods: At the Hospital Guillermo Grant Benavente's Departament of Obstetrics and Gynecology, in Concepción, Chile, 2001 a comparative, cross sectional and correlational study was conducted. The study group were pregnant adolescents who deserted from school system, divided in two subgroups: 86 adolescents who deserted before pregnancy and 130 who deserted during pregnancy. Results: Twenty percent of teenagers that deserted from school before pregnancy belonged to a sublevel of poverty, compared with 5 percent of those who deserted during pregnancy. Flunk was frequent in both but higher in girls that deserted before pregnancy (46.5 and 36.9 percent respectively, (p <0.001). Economic problems were the main cause of desertion before pregnancy (27.6 percent). Shame (41.6 percent) and obstetric complications (31.7 percent) were the main reasons for deserting during pregnancy. Seventy percent of adolescents who deserted before pregnancy had no educational, working or recreational activities. The parental educational level of both groups was low. Conclusions: There is a relationship between teenage pregnancy and school desertion. Adolescents who deserted from school before pregnancy are more vulnerable (Rev Méd Chile 2004; 132: 65-70).

Helicobacter pylori: análisis de cagA y genotipificación de vacA en Chile: detección de una cepa s2/m1 / Helicobacter pylori: cagA status and vacA genotyping in Chile, detection of a s2/m1 strain

Background: The genes cagA and vacA encode H pylori virulence factors. Aim: To genotype these genes in H pylori strains isolated from patients with upper gastrointestinal symptoms. Material and methods: We studied 50 patients who underwent an upper gastrointestinal endoscopy, with positive culture for H pylori. Detection of cagA and vacA gerotyping was done using polymerase chain reactions. Results: The gene cagA was detected in 19 samples (38 per cent). Signal sequences s1 and s2 of vacA gene were detected in 16 samples each (32 per cent). There was simultaneous amplification of s1 and s2 in 6 samples and they were not detected in 9 samples. The middle region of vacA was m1 in 9 samples, m2 in 29 samples and there was simultaneous amplification of m1 and m2 in 12 samples. In 16 samples (32 per cent), more than one type of signal sequence or medial region was detected. Of those patients in whom vacA was the only genotype detected, 15 were s2/m2, 7 were s1/m1, 4 were s1/m2 and 1 was s2/m1. Conclusions: In these patients, the infection with cagA- H pylori strains, predominates, the prevalence of infection with s1 or s2 strains is similar and the predominant medial region is m2

Susceptibilidad in vitro de cepas de helicobacter pylori: aislamiento de cepas resistentes a claritromicina / In vitro antimicrobial susceptibility of helicobacter pylori strains isolated in Chile

Background: Our laboratory has carried out an epidemiological surveillance of Helicobacter pylori antimicrobial susceptibility since 1997. Aim: To report the antimicrobial susceptibility of H pylori strains, isolated in Chile from August 1997 to August 2000. Material and methods: Ninety one H pylori strains, obtained from antral gastric biopsies during upper gastrointestinal endoscopies were studied. Susceptibility towards clarithromycin, amoxicillin, bismuth subcitrate and metronidazole was studied by an agar diffusion technique. Results: All strains were susceptible to amoxicillin and two strains were resistant to clarithromycin. Forty two percent of strains were resistant to metronidazole and 13 per cent were resistant to bismuth subcitrate. Conclusions: These results underscore the need to maintain an epidemiological surveillance of H pylori antimicrobial susceptibility, to modify its eradication therapy accordingly

Estudio de algunas propiedades inmunológicas de lipopolisacáridos extraídos de cepas de helicobacter pylori aisladas de biopsias gástricas / Lipopolysaccharide extracted from gastric biopsies isolated H. pylori strains, immunological properties

Helicobacter pylori es considerado el principal agente responsable de gastritis y úlcera duodenal en el hombre. La participación de factores de virulencia en este microorganismo no ha sido totalmente establecida. Sin embargo, se han descrito algunos determinantes de patogenicidad que serían responsables de la aparición de la enfermedad en humanos. El lipopolisacárido (LPS), ha sido un factor poco estudiado en este microorganismo, al que sólo en los últimos años se le ha conferido importancia en la infección por H. pylori. El objetivo de este estudio fue determinar la actividad linfoproliferativa y niveles de inducción de secreción de FNT alfa por LPS extraídos de cepas de H. pylori en células esplénicas de ratón. Para esto, se trabajó con cuatro cepas bacterianas a las que se les extrajo el LPS por el método fenol/agua en caliente descrito por Westphal y Jann. Se realizaron cultivos celulares los que fueron incubados con 1, 10 y 100 µg/ml de LPS en el ensayo mitogénico y con 10 µg/ml en la liberación de FNT alfa. La actividad linfoproliferativ se determinó por la captación de timidina tritiada por los linfocitos B y la determinación de FNT alfa se realizó en los sobrenadantes de los cultivos, a los que se les cuantificó por ELISA la citoquina liberada por los distintos LPS. Como controles se utilizó LPS comerciales rugoso y liso de salmonella typhimurium. Los resultados muestran que todas las preparaciones de LPS de H. pylori inducen actividad mitogénica y estimulan la síntesis de FNT alfa en células esplénicas de ratón. En conclusión, se sugiere un importante rol de LPS como factor de virulencia en esta especie el que estaría contribuyendo a su patogenicidad para el hombre

Estudio de susceptibilidad al vino tinto chileno y al resveratrol sobre cepas de helicobacter pylori / Helicobacter pylori strains susceptibility to chilean red wine and resveratrol

En los últimos años se han estudiado numerosas propiedades del vino tinto, algunas relacionadas con la salud humana. Así, se ha observado disminución de enfermedades cardiovasculares e infección por H. pylori en bebedores moderados, propiedad que podría estar condicionada a la presencia de resveratrol en el vino. En este trabajo, se investigó la actividad anti H. pylori de 16 vinos tintos chilenos (cepas Cabernet Sauvignon, Cabernet Merlot, Cabernet Orgánico y Pinot Noir) y de extractos activos de dos vinos seleccionados al azar, utilizando el método de difusión en agar. El 100 por ciento de los vinos tintos en estudio presentó algún grado de actividad antibacteriana sobre las seis cepas de H. pylori estudiadas. Por otra parte, las cepas fueron heterogéneas en su susceptibilidad frente a un mismo vino. El extracto activo (extracto diclorometánico) de los dos vinos seleccionados al azar demostró buena actividad sobre todas las cepas ensayadas, y el compuesto activo principal resultó ser el resveratrol. Sólo una de las seis cepas fue moderadamente resistente a 80 µg/ml del compuesto puro, obtenido comercialmente. Los resultados presentados indican que los vinos tintos chilenos tienen actividad antibacteriana sobre H. pylori, la cual depende principalmente de la presencia de resveratrol

Actividad inhibitoria y bactericida de ciprofloxacina, temafloxacina y tosufloxacina sobre Staphylococcus spp. Aislados en hospitales de ciudades chilenas / Inhibitory and bactericidal activity of ciprofloxacin, temafloxacin and tosufloxacin against staphylococcus isolated from chilean hospitals

Inhibitory and bactericidal activities of ciprofoxacin, temafloxacin and tosufloxacin were determined against isolates of Staphylococcus aureus and coagulase negative Staphylococci from various chilean hospitals. Time-kill experiments were performed against one selected strain of each of these bacterial isolates. Tosufloxacin showed highest activity against isolates of Staphylococci either methicillin resistant and methicillin susceptible. Ciprofloxacin was slightly less active temafloxacin

Mecanismos enzimáticos de resistencia a antibióticos aminoglicósidos en bacilos gram negativos de hospitales chilenos / Enzymatic mechanisms of resistance to aminoglycoside antibiotics in gram negative bacilli from chilean hospitals

The presence of aminoglycoside modifying enzyme (AMEs) has been investigated by an agar diffusion method, in 344 strains of aminoglycoside-resistant Gram negative bacilli isolated in different Chilean hospitals. Most of the strains exhibited a combination of enzymatic mechanism of resistance, but 2 acetylatting (AAC(3)II and AAC(6')I) and one phosphorylating (APH(3')I) enzymes were mechanism detected in the strains. A significant increase in the frequency of strains producing AAC(6')I), possibly due to wide use of amikacin, has been found when results were compared with those of a report published in 1985

Actividad inhibitoria y bactericida de cinco fluoroquinolonas sobre cepas multirresistentes de escherichia coli, acinetobacter baumanni y pseudomonas aeruginosa aisladas en hospitales de ciudades chilenas / Inhibitory and bactericidal activity of 5 fluoroquinolones over multiresistent strains of escherichia coli, acinetobacter baumanni and pseudomonas aeruginosa isolated in hospitals of chilean cities

Inhibitory and bactericidal activities of ciprofloxacin, temafloxacin, tosufloxacin, fleroxacin and E-4868 were determined against isolates of escherichia coli, acinetobacter baumannii and pseudomonas aeruginosa from varius chilean hospitals. Time-kill experiments were perfomed against one selected strain of these bacterial species. All quinolones showed high activity against E. coli as well as lower activity against P. aeruginosa and A. baumannii. Ciprofloxacin, temafloxacin, tosufloxacin, fleroxacin and E-4868 were rapidly bactericidal against E. coli, but only ciprofloxacin rapidly killed the strain of P. aeruginosa. E-4868 and tosufloxacin were also rapidly bactericidal against A. baumannii