Percepciones y creencias sobre criopreservación embrionaria en mujeres y hombres que se realizan técnicas de reproducción asistida en Santiago, Chile / Perceptions and beliefs about embryo cryopreservation in women and men who have assisted reproductive techniques in Santiago, Chile

RESUMEN Introducción y objetivos: Aunque la criopreservación embrionaria es frecuentemente utilizada como parte de las técnicas de reproducción asistida, no existe información cuantitativa de cómo las parejas infértiles viven la experiencia de tener embriones criopreservados en Chile. El objetivo del estudio fue examinar las percepciones y creencias que tienen mujeres y hombres respecto de sus embriones criopreservados, sus perspectivas respecto de la donación reproductiva y destino de los embriones remanentes. Metodología: 153 mujeres y hombres con embriones criopreservados provenientes de un hospital público, Instituto de Investigaciones Materno Infantil y un centro privado, Clínica Las Condes, en Santiago, Chile, respondieron durante mayo 2015 a mayo 2016 un cuestionario en línea, anónimo, respecto de sus percepciones y creencias sobre criopreservación embrionaria. Resultados: Los encuestados reconocen a sus embriones criopreservados como un hijo (53.2%) o un proyecto de hijo (40.7%). Sólo 8% los considera un grupo organizado de células; sobre el 60% rechaza la opción de descartarlos o usarlos para investigación. Los participantes del hospital público tenían mayor disposición a donar sus embriones remanentes a otras parejas que aquellos del privado (61% vs 40%; P=0.016). Un 34% de las personas encuestadas estuvo de acuerdo con donar embriones a parejas de un mismo sexo. Conclusión: Este estudio muestra que las personas chilenas tienen un vínculo emocional con sus embriones criopreservados y no consideran descartarlos. Los resultados de este estudio pueden servir para dar adecuada consejería a las personas que se realizan técnicas de reproducción asistida, de tal modo de tomar decisiones informadas respecto de la criopreservación.

ABSTRACT Background and objetive: Although embryo cryopreservation is frequently used as part of assisted reproductive technology, quantitave information addressing how infertile couples live the experience of having cryopreserved embryos is lacking in Chile. The aim of this study is to examine men and women's perception and beliefs regarding their cryopreserved embryos, as well as their perspective on embryo donation and disposition. Methods: 153 women and men with frozen embryos from a public hospital, Instituto de Investigactiones Materno Infantil, and a private clinic, Clínica Las Condes, in Santiago, Chile, responded between May 2015 and May 2016 to an anonymous online survey addressing their perceptions and beliefs concerning their cryopreserved embryos. Results: Respondents considered their frozen embryos to be equivalent to a child (53.2%) or a potential child (40.7%). Only 8% regard them as an organized group of cells. Over 60% of respondents disagree with destroying surplus embryos or using them for research. Participants from the public hospital are more willing to donate their embryos to another couple than those from the private center (61% vs 40%; P=0.016); 34% of respondents agreed to donate surplus embryos to same sex couples. Conclusion: This study reveals that Chilean couples are emotionally bound to their frozen embryos, and that discarding them is not an option. The results from this survey will help strengthen counseling for couples to enable them to make informed decisions regarding their surplus embryos.

Percepciones y creencias sobre criopreservación embrionaria en mujeres y hombres que se realizan técnicas de reproducción asistida en Santiago, Chile.

BACKGROUND AND OBJETIVE: Although embryo cryopreservation is frequently used as part of assisted reproductive technology, quantitave information addressing how infertile couples live the experience of having cryopreserved embryos is lacking in Chile. The aim of this study is to examine men and women's perception and beliefs regarding their cryopreserved embryos, as well as their perspective on embryo donation and disposition. Methods: 153 women and men with frozen embryos from a public hospital, Instituto de Investigactiones Materno Infantil, and a private clinic, Clínica Las Condes, in Santiago, Chile, responded between May 2015 and May 2016 to an anonymous online survey addressing their perceptions and beliefs concerning their cryopreserved embryos. RESULTS: Respondents considered their frozen embryos to be equivalent to a child (53.2%) or a potential child (40.7%). Only 8% regard them as an organized group of cells. Over 60% of respondents disagree with destroying surplus embryos or using them for research. Participants from the public hospital are more willing to donate their embryos to another couple than those from the private center (61% vs 40%; P=0.016); 34% of respondents agreed to donate surplus embryos to same sex couples. CONCLUSION: This study reveals that Chilean couples are emotionally bound to their frozen embryos, and that discarding them is not an option. The results from this survey will help strengthen counseling for couples to enable them to make informed decisions regarding their surplus embryos.

INTRODUCCIÓN Y OBJETIVOS: Aunque la criopreservación embrionaria es frecuentemente utilizada como parte de las técnicas de reproducción asistida, no existe información cuantitativa de cómo las parejas infértiles viven la experiencia de tener embriones criopreservados en Chile. El objetivo del estudio fue examinar las percepciones y creencias que tienen mujeres y hombres respecto de sus embriones criopreservados, sus perspectivas respecto de la donación reproductiva y destino de los embriones remanentes. METODOLOGÍA: 153 mujeres y hombres con embriones criopreservados provenientes de un hospital público, Instituto de Investigaciones Materno Infantil y un centro privado, Clínica Las Condes, en Santiago, Chile, respondieron durante mayo 2015 a mayo 2016 un cuestionario en línea, anónimo, respecto de sus percepciones y creencias sobre criopreservación embrionaria. RESULTADOS: Los encuestados reconocen a sus embriones criopreservados como un hijo (53.2%) o un proyecto de hijo (40.7%). Sólo 8% los considera un grupo organizado de células; sobre el 60% rechaza la opción de descartarlos o usarlos para investigación. Los participantes del hospital público tenían mayor disposición a donar sus embriones remanentes a otras parejas que aquellos del privado (61% vs 40%; P=0.016). Un 34% de las personas encuestadas estuvo de acuerdo con donar embriones a parejas de un mismo sexo. CONCLUSIÓN: Este estudio muestra que las personas chilenas tienen un vínculo emocional con sus embriones criopreservados y no consideran descartarlos. Los resultados de este estudio pueden servir para dar adecuada consejería a las personas que se realizan técnicas de reproducción asistida, de tal modo de tomar decisiones informadas respecto de la criopreservación.

High Helicobacter pylori resistance to metronidazole and clarithromycin in Brazilian children and adolescents.

OBJECTIVE: The aim of the present study was to assess the primary and secondary resistance of Helicobacter pylori strains to clarithromycin, amoxicillin, furazolidone, tetracycline, and metronidazole, the conventional antibiotics presently used in Brazilian children and adolescents. METHODS: Seventy-seven consecutive H pylori strains, 71 of 77 strains obtained from patients without previous eradication treatment for H pylori infection, and 6 strains from patients in whom previous eradication treatment had failed. RESULTS: Global rate of resistance was 49.3% (38/77): 40% of strains were resistant to metronidazole, 19.5% to clarithromycin, and 10.4% to amoxicillin. All of the tested H pylori strains were susceptible to furazolidone and tetracycline. Multiple resistance were detected in 18.2% (14/77 patients) of the strains: 6 of 14 (43%) simultaneously resistant to clarithromycin and metronidazole; 5 of 14 (36%) to amoxicillin and metronidazole; 2 of 14 (14%) to amoxicillin, clarithromycin, and metronidazole; and 1 of 14 (7%) to clarithromycin and amoxicillin. CONCLUSIONS: The high resistance rate to metronidazole and clarithromycin observed in clinical H pylori isolates can exclude these antimicrobials in empirical eradication treatment in Brazil. Otherwise, furazolidone and tetracycline presented no resistance. Properly assessing the risks and benefits, these 2 antimicrobials and their derivatives could be used in empirical eradication schedules, both associated with amoxicillin, which showed a low resistance rate despite its wide use in pediatric patients.

Prevalência da infecção por Helicobacter pylori e de parasitoses intestinais em crianças do Parque Indígena do Xingu / Prevalence of Helicobacter pylori infection and intestinal parasitosis in children of the Xingu Indian Reservation

OBJETIVO: Avaliar a prevalência da infecção por Helicobacter pylori e sua associação com parasitoses intestinais em crianças da comunidade indígena do Parque Indígena do Xingu. MÉTODOS: Foram incluídas 245 crianças indígenas entre 2 e 9 anos, de seis aldeias da região do rio Xingu, afluente do Amazonas. H. pylori foi detectado pelo teste respiratório com ureia-13C. Foram coletadas amostras de ar expirado, em jejum e 30 minutos após a ingestão de 50 mg de ureia-13C diluída em 100 mL de água aromatizada com suco de maracujá. Foram coletadas amostras de fezes de 202/245 (82,4 por cento) crianças para exame protoparasitológico. RESULTADOS: A prevalência do H. pylori foi de 73,5 por cento. Foi observada associação significativa do H. pylori com maior idade entre as diferentes aldeias e etnias. Resultaram positivas para a presença de parasitas 97,5 por cento (198/202) das amostras de fezes, sem associação com a infecção por H. pylori. Encontrou-se, na análise multivariada, uma relação entre a infecção por giárdia e o H. pylori. As etnias Kisêjê [odds ratio (OR) = 3,36] e Kaibi (OR = 4,00), e as aldeias Tuiararé (OR = 8,10), Ngojwere (OR = 4,10), Capivara (OR = 4,88), Diauarum (OR = 1,85) e Pavuru (OR = 1,40) foram fatores de risco para a infecção por H. pylori. CONCLUSÕES: Foi encontrada alta prevalência de H. pylori e de parasitose intestinal em crianças nas comunidades presentemente investigadas. No entanto, houve diferença significativa na prevalência do H. pylori entre as diversas aldeias estudadas. Verificou-se associação entre a presença de giárdia e a infecção por H. pylori.

OBJECTIVE: To evaluate the prevalence of Helicobacter pylori infection and its association with intestinal parasitoses in children from indigenous communities of the Xingu Indian Reservation, in Brazil. METHODS: A total of 245 Native Brazilian children between 2 and 9 years of age, from six villages of the Xingu River region, a tributary of the Amazon River, were assessed. H. pylori was detected using the 13C-urea breath test. Breath samples were collected at baseline and 30 minutes after ingestion of 50 mg of 13C-urea diluted with 100 mL of water flavored with passion fruit juice and sweetener. Stool samples were collected for the stool ova and parasites exam for 202/245 (82.4 percent) children. RESULTS: The overall prevalence of H. pylori was 73.5 percent. A significant association of H. pylori with increased age was observed among the different villages and ethnic groups. Positive results for the presence of parasites - 97.5 percent (198/202) - from the stool samples collected showed no association with H. pylori. Giardia showed an association with H. pylori in the multivariate analysis. Risk factors for H. pylori infection were observed in Kisêjê and Kaibi ethnic groups (OR [odds ratio] = 3.36 and 4.00, respectively), as well as in Tuiararé, Ngojwere, Capivara, Diauarum, and Pavuru villages (OR = 8.10, 4.10, 4.88, 1.85, and 1.40, respectively). CONCLUSIONS: H. pylori infection is highly prevalent in these communities, as well as intestinal parasitoses. However, there were significant differences in the prevalence of H. pylori among the diverse villages studied. Giardia was closely associated with H. pylori infection.

Prevalence of Helicobacter pylori infection and intestinal parasitosis in children of the Xingu Indian Reservation.

OBJECTIVE: To evaluate the prevalence of Helicobacter pylori infection and its association with intestinal parasitoses in children from indigenous communities of the Xingu Indian Reservation, in Brazil. METHODS: A total of 245 Native Brazilian children between 2 and 9 years of age, from six villages of the Xingu River region, a tributary of the Amazon River, were assessed. H. pylori was detected using the (13)C-urea breath test. Breath samples were collected at baseline and 30 minutes after ingestion of 50 mg of (13)C-urea diluted with 100 mL of water flavored with passion fruit juice and sweetener. Stool samples were collected for the stool ova and parasites exam for 202/245 (82.4%) children. RESULTS: The overall prevalence of H. pylori was 73.5%. A significant association of H. pylori with increased age was observed among the different villages and ethnic groups. Positive results for the presence of parasites - 97.5% (198/202) - from the stool samples collected showed no association with H. pylori. Giardia showed an association with H. pylori in the multivariate analysis. Risk factors for H. pylori infection were observed in Kisêjê and Kaibi ethnic groups (OR [odds ratio] = 3.36 and 4.00, respectively), as well as in Tuiararé, Ngojwere, Capivara, Diauarum, and Pavuru villages (OR = 8.10, 4.10, 4.88, 1.85, and 1.40, respectively). CONCLUSIONS: H. pylori infection is highly prevalent in these communities, as well as intestinal parasitoses. However, there were significant differences in the prevalence of H. pylori among the diverse villages studied. Giardia was closely associated with H. pylori infection.

Prevalência de parasitoses intestinais em crianças do Parque Indígena do Xingu / Prevalence of intestinal parasitoses in children at the Xingu Indian Reservation

OBJETIVO: Avaliar a prevalência da parasitose intestinal em crianças indígenas de 2 a 9 anos. MÉTODOS: Para a realização do exame protoparasitológico, foram convidadas todas as crianças de 2 a 9 anos, de seis aldeias localizadas no Médio e Baixo Xingu: Pavuru, Moygu, Tuiararé, Diauarum, Capivara e Ngojwere. Para a conservação das amostras de fezes, foi utilizado o kit coletor Paratest® (Diagnostek, Brasil). As amostras foram transportadas para São Paulo. A pesquisa de helmintos e protozoários foi feita através do método de Hoffman, com posterior pesquisa de ovos e cistos por microscopia óptica. Foram feitas duas coletas com intervalo de 1 ano. RESULTADOS: Não houve diferença significativa entre as idades médias das crianças provenientes das seis aldeias. Resultaram positivas para a presença de parasitas, 97,5 por cento (198/202) e 96,1 por cento (98/102) na primeira e segunda coletas, respectivamente, sem associação estatística entre a idade. Realizaram o exame parasitológico de fezes nos 2 anos, 89/102 (87,3 por cento). Após 1 ano, não houve diferença na proporção de pacientes infestados por protozoários (93,3 por cento em 2007 contra 93,3 por cento em 2008, McNemar = 0,01, p = 0, 1) ou por helmintos (37,1 por cento em 2007 contra 38,2 por cento em 2008, McNemar = 0,03, p = 0,85). Houve diferença significativa quanto à prevalência de Entamoeba coli em 2007 (43,8 por cento) e 2008 (61,8 por cento) (McNemar's Chi 6,1; p = 0,0135). Não houve diferenças significativas quanto aos outros parasitas após comparação dos dois resultados. CONCLUSÃO: A alta prevalência de parasitose intestinal foi compatível com o alto índice de contaminação ambiental dessa comunidade.

OBJECTIVE: To evaluate the prevalence of intestinal parasitoses in Native Brazilian children from 2 to 9 years old. METHODS: A search for ova and parasites was conducted in the stools of children between 2 to 9 years old living in six indigenous villages located in the Middle and Lower Xingu River, to wit: Pavuru, Moygu, Tuiararé, Diauarum, Capivara, and Ngojwere. The study utilized the Paratest kit® (Diagnostek, Brazil) to preserve collected stools. Fecal samples were shipped to the Laboratory of the Pediatric Gastroenterology Division of the UNIFESP/EPM, in São Paulo, for analysis. The search for ova and parasites was performed utilizing the Hoffman method, and later through optical microscopic evaluation. Fecal samples were collected one year apart from each other. RESULTS: There were no significant statistical differences between the mean ages of the children from the six indigenous villages studied. The search for ova and parasites found positive results for the stools of 97.5 percent (198/202) and 96.1 percent (98/102) of children in the first and second collections, respectively. There was no statistical association with the children's age. The search performed one year later found no differences in the proportion of parasites identified in the first collection for protozoa (93.3 percent in 2007 versus 93.3 percent in 2008, McNemar = 0.01, p = 0.1) or for helminths (37.1 percent in 2007 versus 38.2 percent in 2008, McNemar = 0.03, p = 0.85). There were significant differences in prevalence of Entamoeba coli between 2007 (43.8 percent) and 2008 (61.8 percent) (McNemar Chi 6.1; p = 0.0135). There were no significant differences for other parasites when comparing the results of the two studies. CONCLUSION: The high prevalence of intestinal parasitosis matched the elevated rates of environmental contamination in this indigenous community.

Prevalence of intestinal parasitoses in children at the Xingu Indian Reservation.

OBJECTIVE: To evaluate the prevalence of intestinal parasitoses in Native Brazilian children from 2 to 9 years old. METHODS: A search for ova and parasites was conducted in the stools of children between 2 to 9 years old living in six indigenous villages located in the Middle and Lower Xingu River, to wit: Pavuru, Moygu, Tuiararé, Diauarum, Capivara, and Ngojwere. The study utilized the Paratest kit® (Diagnostek, Brazil) to preserve collected stools. Fecal samples were shipped to the Laboratory of the Pediatric Gastroenterology Division of the UNIFESP/EPM, in São Paulo, for analysis. The search for ova and parasites was performed utilizing the Hoffman method, and later through optical microscopic evaluation. Fecal samples were collected one year apart from each other. RESULTS: There were no significant statistical differences between the mean ages of the children from the six indigenous villages studied. The search for ova and parasites found positive results for the stools of 97.5% (198/202) and 96.1% (98/102) of children in the first and second collections, respectively. There was no statistical association with the children's age. The search performed one year later found no differences in the proportion of parasites identified in the first collection for protozoa (93.3% in 2007 versus 93.3% in 2008, McNemar = 0.01, p = 0.1) or for helminths (37.1% in 2007 versus 38.2% in 2008, McNemar = 0.03, p = 0.85). There were significant differences in prevalence of Entamoeba coli between 2007 (43.8%) and 2008 (61.8%) (McNemar Chi 6.1; p = 0.0135). There were no significant differences for other parasites when comparing the results of the two studies. CONCLUSION: The high prevalence of intestinal parasitosis matched the elevated rates of environmental contamination in this indigenous community.

[Analysis of molecular fingerprint and virulence factors of Helicobacter pylori strains]. / Análise das impressões digitais de DNA e de fatores de virulência de linhagens de Helicobacter pylori.

BACKGROUND: Helicobacter pylori is now accepted as the most important agent of gastritis in humans, as well as a risk factor for peptic ulcer disease and gastric carcinoma. The outcome of the infection is related to several factors, among them bacterial ones such as cagA and vacA s1m1 genotype. Random amplified polymorphic DNA (RAPD)-PCR, has been used to generate DNA fingerprints to evaluate similarity among strains within a bacterial species. AIM: To assess the association between RAPD fingerprinting, virulence factors and the disease. METHODS: H. pylori was isolated from 112 patients (41 with gastritis; 19 with gastric ulcers; 38 with duodenal ulcer disease; and 14 with gastroesophageal reflux disease). Allelic variants of cagA and vacA were identified using the polymerase chain reaction (PCR) and the fingerprints were generated by RAPD-PCR. RESULTS: There was a strong association between the genotype vacA s1m1 and duodenal ulcers. Although RADP-PCR is a very useful tool in genotyping H. pylori, no significant correlation between the diseases studied and DNA fingerprint was detected neither with fingerprint and different vacA and, cagA genotypes. CONCLUSIONS: The extension of our analysis to patients with well-characterized gastric diseases may provide significant information on the relationship between vacA genotypes and clinical outcomes of H. pylori infection.

Differentially expressed genes in response to amoxicillin in Helicobacter pylori analyzed by RNA arbitrarily primed PCR.

Because the molecular mechanism of amoxicillin resistance in Helicobacter pylori seems to be partially explained by several mutational changes in the pbp1A gene, the aim of the present study was to evaluate the gene expression pattern in response to amoxicillin in the Amx(R) Hardenberg strain using RNA arbitrarily primed PCR (RAP-PCR). In the experiments, c. 100 differentially expressed RAP-PCR products were identified using five arbitrary primers. The cDNAs that presented the highest levels of induction or repression were cloned and sequenced, and the sequences were compared with those present in databases using the blast search algorithm. The differential expression of the isolated cDNAs was confirmed by real-time PCR. The preliminary results showed that amoxicillin alters the expression of five cDNAs involved in biosynthesis, two involved with pathogenesis, four related to cell envelope formation, two involved in cellular processes, three related with transport and binding proteins, one involved with protein degradation, one involved with energy metabolism and seven hypothetical proteins. Further analysis of these cDNAs will allow a better comprehension of both the molecular mechanism(s) of amoxicillin resistance and the adaptative mechanism(s) used by H. pylori in the presence of this antibiotic.

Análise das impressões digitais de DNA e de fatores de virulência de linhagens de Helicobacter pylori / Analysis of molecular fingerprint and virulence factors of Helicobacter pylori strains

RACIONAL: Helicobacter pylori é hoje aceito como o principal agente etiológico de gastrite em seres humanos e fator de risco para úlcera péptica e câncer gástrico. A evolução da infecção está relacionada a diversos fatores, inclusive bacterianos, como presença do gene cagA e o genótipo vacA s1m1, associados ao desenvolvimento de úlcera e adenocarcinoma gástrico. A técnica de RAPD ("random amplified polimorphic") tem sido amplamente utilizada para obtenção de impressões digitais de DNA para examinar a similaridade entre linhagens. OBJETIVOS: Avaliar a presença de cagA e alelos do vacA em amostras de H. pylori e associar os achados com a doença apresentada e também investigar possível clonicidade entre os fatores de virulência e as doenças com a impressão digital de DNA gerada pelo RAPD-PCR. MÉTODOS: Foram incluídas 112 amostras provenientes de pacientes com diferentes laudos endoscópicos: gastrite (n = 41), esofagite de refluxo (n = 14), úlcera gástrica (n = 19) e úlcera duodenal (n = 38). A análise dos fatores de virulência da bactéria foi feita por PCR e as impressões digitais de DNA foram estabelecidas pelo método de RAPD-PCR. RESULTADOS: Os resultados obtidos indicam que houve uma associação significativa entre úlcera duodenal e o mosaico vacA s1m1. Analisando-se os padrões de bandas geradas pelo RAPD-PCR, sete diferentes dendogramas foram construídos e não foi possível detectar associação significativa entre os agrupamentos, sugerindo que as amostras não possuem perfil clonal. CONCLUSÃO: Os resultados reforçam a importância do gene vacA como um marcador de virulência do H. pylori. O RAPD da impressão digital de DNA realizado foi incapaz de associar o padrão de bandas com as enfermidades e os genótipos de vacA e cagA.

BACKGROUND: Helicobacter pylori is now accepted as the most important agent of gastritis in humans, as well as a risk factor for peptic ulcer disease and gastric carcinoma. The outcome of the infection is related to several factors, among them bacterial ones such as cagA and vacA s1m1 genotype. Random amplified polymorphic DNA (RAPD)-PCR, has been used to generate DNA fingerprints to evaluate similarity among strains within a bacterial species. AIM: To assess the association between RAPD fingerprinting, virulence factors and the disease. METHODS: H. pylori was isolated from 112 patients (41 with gastritis; 19 with gastric ulcers; 38 with duodenal ulcer disease; and 14 with gastroesophageal reflux disease). Allelic variants of cagA and vacA were identified using the polymerase chain reaction (PCR) and the fingerprints were generated by RAPD-PCR. RESULTS: There was a strong association between the genotype vacA s1m1 and duodenal ulcers. Although RADP-PCR is a very useful tool in genotyping H. pylori, no significant correlation between the diseases studied and DNA fingerprint was detected neither with fingerprint and different vacA and, cagA genotypes. CONCLUSIONS: The extension of our analysis to patients with well-characterized gastric diseases may provide significant information on the relationship between vacA genotypes and clinical outcomes of H. pylori infection.

Multiple mutations in or adjacent to the conserved penicillin-binding protein motifs of the penicillin-binding protein 1A confer amoxicillin resistance to Helicobacter pylori.

BACKGROUND: Amoxicillin-based therapies are highly effective for the treatment of Helicobacter pylori infections, but the efficacy may decrease as the incidence of amoxicillin resistance is increasing. So far, the molecular mechanism underlying stable amoxicillin resistance has only been identified for a few naturally occurring amoxicillin-resistant (Amx) H. pylori isolates, and is mediated by mutations in penicillin-binding protein 1A (PBP1A). In this study the molecular mechanism underlying amoxicillin resistance of seven additional Amx H. pylori isolates has been established. METHODS: H. pylori strain 26695 (minimal inhibitory concentration (MIC) 0.125 mg/l) was naturally transformed with total DNA and pbp1A polymerase chain reaction (PCR) products from the seven Amx H. pylori isolates, and the MIC of amoxicillin and pbp1A gene sequence of the obtained Amx transformants were determined. RESULTS: Replacement of the wild-type pbp1A gene of H. pylori reference strain 26695 by the pbp1A gene of the Amx H. pylori isolates resulted in an increased MIC (0.5-1.0 mg/l). Sequence analysis of the smallest PBP1A fragments able to transfer the resistance indicated that several amino acid substitutions in or adjacent to the second (SKN402-404) and third (KTG555-557) conserved penicillin-binding protein motifs (PBP-motifs) mediate amoxicillin resistance in H. pylori. This was confirmed by site-directed mutagenesis using oligonucleotides that contained defined mutations in or adjacent to these PBP-motifs. CONCLUSION: In naturally occurring Amx H. pylori isolates, amoxicillin resistance is mediated by various mutational changes located in or adjacent to the second and third PBP-motifs of the PBP1A. Although we cannot exclude the role of the other genes in amoxicillin resistance, it is likely that multiple mutational changes in the PBP1A gene are the predominant cause of amoxicillin resistance in H. pylori. The findings of this study currently preclude the rapid detection of amoxicillin resistance in H. pylori by molecular tests.

The influence of endoscopic procedures upon the contamination of Helicobacter pylori cultures.

BACKGROUND: Among the various diagnostic methods for the detection of Helicobacter pylori infection, histological examination and microbiological processing of gastric biopsy samples are assumed to be the gold standard techniques. AIMS: Since H. pylori culture can be affected by the presence of non-H. pylori bacteria, we evaluated the efficacy of endoscope disinfection and the influence of endoscopic procedures on culture contamination. PATIENTS AND METHODS: The procedures used during the first two routine endoscopies were evaluated during 28 consecutive days. Endoscopy room, forceps and endoscopic channel were analyzed before and after the beginning of normal procedures. After disinfection, a biopsy simulation was performed to verify the gastric bacteria. RESULTS: Endoscope disinfection removed all organisms from forceps and endoscopic channel with 100% efficacy. The most frequent non-H. pylori bacteria detected were Streptococcus bovis, Enterobacter hormaechei, and Staphylococcus aureus. The sensibility of the H. pylori culture was affected by the presence of non-H. pylori bacteria. CONCLUSION: The risk of transmission of microorganisms was not detectable when sterilized biopsy forceps and stringent disinfection standards were employed. Whilst S. bovis and E. hormaechei may be common in gastric microbial flora, the presence of P. aeruginosa and S. aureus indicated that the manipulation of biopsies could be responsible for culture contamination with these bacteria.

The influence of endoscopic procedures upon the contamination of Helicobacter pylori cultures

RACIONAL E OBJETIVOS: Dentre os vários métodos diagnósticos empregados na detecção da infecção por Helicobacter pylori, o diagnóstico histológico e a análise microbiológica de biopsia gástrica são consideradas as técnicas mais sensíveis. Entretanto, a sensibilidade da cultura de H. pylori pode ser reduzida pela presença de outras bactérias. Desse modo, avaliou-se a eficácia da desinfecção do endoscópio e a influência dos procedimentos endoscópicos na contaminação da cultura bacteriana. Para tal, as duas primeiras endoscopias durante 28 dias consecutivos foram estudadas. A sala de endoscopia, o fórceps e o canal do endoscópio foram analisados antes e depois do início dos procedimentos endoscópicos rotineiros. Depois da desinfecção, uma simulação de coleta de biopsia foi realizada para verificar a presença das bactérias gástricas. RESULTADOS: A desinfecção do endoscópio foi capaz de remover todos os organismos do fórceps e do canal do endoscópio. As bactérias não-H. pylori mais freqüentemente detectadas foram Streptococcus bovis, Enterobacter hormaechei e Staphylococcus aureus. Em alguns casos a sensibilidade da cultura do H. pylori foi reduzida pela presença de bactérias contaminantes. CONCLUSAO: Não houve risco de transmissão de microorganismos quando fórceps esterilizados e desinfecção adequada foram empregadas. A presença de S. bovis e E. hormaechei parece ser comum na microflora gástrica; por outro lado, a detecção de P. aeruginosa e S. aureus indica que a manipulação de biopsias pode ser responsável pela contaminação da cultura por essas bactérias.

Detection of high-level tetracycline resistance in clinical isolates of Helicobacter pylori using PCR-RFLP.

Tetracycline is one of four antibiotics commonly used for the treatment of Helicobacter pylori infection, but its effectiveness is decreasing as the incidence of tetracycline resistance is increasing. In five Brazilian tetracycline-resistant (Tet(R)) H. pylori isolates, high-level tetracycline resistance is mediated by the triple-base-pair substitution AGA(926-928)-->TTC in both 16S rRNA genes, as was previously observed in two independent high-level Tet(R) H. pylori strains. A polymerase chain reaction-based restriction fragment length polymorphism (PCR-RFLP) assay was developed for the detection of the AGA(926-928)-->TTC substitution, and confirmed the presence of the aforementioned triple-base-pair substitution in all five Brazilian Tet(R) isolates. This PCR-RFLP-based approach distinguishes the high-level Tet(R) isolates from low-level Tet(R) and Tet(S) H. pylori strains and thus allows the direct detection of Tet(R) H. pylori isolates.

Mutations in the 23S rRNA gene are associated with clarithromycin resistance in Helicobacter pylori isolates in Brazil.

BACKGROUND: Resistance of Helicobacter pylori to clarithromycin has been associated with A2142G and A2143G point mutations in the 23S rRNA gene. Thus, the purpose of the present study was to determine the prevalence of each mutation in 52 clarithromycin-resistant H. pylori strains and to characterize the influence each type of mutation on the MIC. METHODS: The MIC for clarithromycin was determined by the agar dilution method, and the point mutations of H. pylori were detected by PCR followed by restriction fragment length polymorphism. RESULTS: Clarithromycin MICs ranged from 2 to >256 microgram ml-1 among the 52 strains included in this study. Both the A2142G and the A2143G mutations were present in 94.2% of clarithromycin-resistant H. pylori strains examined. A relationship was observed between the presence of the A2142G mutation and the highest MIC values (p = 0.01). CONCLUSION: In an H. pylori-infected population, the A2142G mutation may incur to a greater probability of treatment failure if clarithromycin is used.

Analysis of antimicrobial susceptibility and virulence factors in Helicobacter pylori clinical isolates.

BACKGROUND: In this study, we evaluated the prevalence of primary resistance of Brazilian H. pylori isolates to metronidazole, clarithromycin, amoxicillin, tetracycline, and furazolidone. In addition, the vacA, iceA, cagA and cagE genotypes of strains isolated from Brazilian patients were determined and associated with clinical data in an effort to correlate these four virulence markers and antibiotic resistance. METHODS: H. pylori was cultured in 155 H. pylori-positive patients and MICs for metronidazole, clarithromycin, amoxicillin, tetracycline, and furazolidone were determined by the agar dilution method. Genomic DNA was extracted, and allelic variants of vacA, iceA, cagA and cagE were identified by the polymerase chain reaction. RESULTS: There was a strong association between the vacA s1/cagA -positive genotype and peptic ulcer disease (OR = 5.42, 95% CI 2.6-11.3, p = 0.0006). Additionally, infection by more virulent strains may protect against GERD, since logistic regression showed a negative association between the more virulent strain, vacA s1/cagA-positive genotype and GERD (OR = 0.26, 95% CI 0.08-0.8, p = 0.03). Resistance to metronidazole was detected in 75 patients (55%), to amoxicillin in 54 individuals (38%), to clarithromycin in 23 patients (16%), to tetracycline in 13 patients (9%), and to furazolidone in 19 individuals (13%). No significant correlation between pathogenicity and resistance or susceptibility was detected when MIC values for each antibiotic were compared with different vacA, iceA, cagA and cagE genotypes. CONCLUSION: The analysis of virulence genes revealed a specific association between H. pylori strains and clinical outcome, furthermore, no significant association was detected among pathogenicity and resistance or susceptibility.

Clinical relevance of the cagA, vacA and iceA genotypes of Helicobacter pylori in Brazilian clinical isolates.

Infection with Helicobacter pylori strains harboring determinants of pathogenicity may lead to a strong inflammatory response in gastric mucosa. In this work, we examined the frequency of the cagA, vacA and iceA genotypes in H. pylori strains isolated from Brazilian patients and correlated these with the clinical manifestations. H. pylori was isolated from 165 patients [30 with non-ulcer dyspepsia cases (NUD); 93 peptic ulcer disease (PUD): 31 gastric ulcers (GU) and 62 duodenal ulcer disease (DU); 18 with erosive gastritis (EG); and 24 gastroesophageal reflux disease (GERD)]. Allelic variants of cagA, vacA and iceA were identified using the polymerase chain reaction. More than one H. pylori strain was detected in 28 cases (17%), and these were excluded from the statistical analysis. We were unable to confirm an association between iceA status and clinical outcome. There was a strong association between the genotype cagA-positive vacA s1 and PUD. However, logistic regression analysis showed that vacA s1 was the only predictive factor for PUD (OR=4.19; 95% CI 1.95-8.98). The presence of the less virulent strain vacA s2 was related to GERD (OR=8.59; 95% CI 2.85-25.91). Our results support the hypothesis that virulent strains may protect against the development of GERD.