Antibiotic resistance of Enterococcus faecalis from persistent endodontic infections / Resistencia antibiótica de Enterococcus faecalis provenientes de infecciones endodónticas persistentes

Enterococci are important nosocomial pathogens due to their intrinsic multiresistance and the acquisition of new antibiotic resistance genes (ARG). Enterococcus faecalis has been shown to be one of the main pathogens in persistent endodontic infections, therefore, the main objective of this study was to evaluate the phenotype and resistance genotype of strains of E. faecalis isolated from teeth with persistent endodontic lesions, to the most commonly prescribed antibiotics in dentistry. Thirteen strains of E. faecalis of different pulsotype were analyzed to evaluate the susceptibility to antibiotics, amoxicillin, amoxicillin/clavulanic acid, tetracycline, erythromycin and metronidazole, using the Epsilometer test (E- test) and the presence of beta-lactamases with nitrocefin test. Finally, the detection of ARG was performed with a molecular polymerase chain reaction (PCR) technique and confirmed by the sequencing of the amplification products. Fisher's exact test was used, using 95 % confidence. Regarding the phenotype of resistance, the evaluated strains, independent of the pulsotype, were totally resistant to the action of metronidazole. Antibiotics with higher minimum inhibitory concentration (MIC) after metronidazole include tetracycline and erythromycin. In contrast, lower MIC are applied to the combination of amoxicillin with clavulanic acid. The nitrocefin test was positive only in one strain. Genotypically, two genetically distant strains isolated from a single patient, presented a genotype of resistance to erythromycin, determined by the presence of the ermB gene. No statistically significant relationship was found between phenotypic resistance and the presence of ARG in relation to erythromycin (p> 0.05). It was concluded that isolates of E. faecalis from persistent endodontic infections showed phenotypes of resistance to several antimicrobial agents, all of which were susceptible to amoxicillin/clavulanic acid. Periodic evaluation of susceptibility to antibiotics is suggested as an important practice for the surveillance of antibiotic resistance in oral strains.

Los enterococos son importantes patógenos nosocomiales debido a su multi resistencia intrínseca y la adquisición de nuevos genes de resistencia a los antibióticos (ARG). Enterococcus faecalis es uno de los principales patógenos en infecciones endodónticas persistentes, por lo tanto, el objetivo principal de este estudio fue evaluar el fenotipo y el genotipo de resistencia de cepas de E. faecalis aisladas de dientes con lesiones endodóncicas persistentes, a los antibióticos comúnmente recetados en odontología. Se analizaron 13 cepas de E. faecalis de diferentes pulsotipos para evaluar la susceptibilidad a los antibióticos, amoxicilina, amoxicilina / ácido clavulánico, tetraciclina, eritromicina y metronidazol, utilizando la prueba de Epsilometría (E-test) y la presencia de beta-lactamasas con prueba de nitrocefina. Finalmente, la detección de ARG se realizó con una técnica molecular de reacción en cadena de la polimerasa (PCR) y se confirmó mediante la secuenciación de los productos de amplificación. Se utilizó la prueba exacta de Fisher, con un 95 % de confianza. En cuanto al fenotipo de resistencia, las cepas evaluadas, independientes del pulsotipo, fueron totalmente resistentes a la acción del metronidazol. Los antibióticos con los valores más altos de concentración mínima inibitoria (CMI) después del metronidazol incluyen tetraciclina y eritromicina. En contraste, las CMI mas bajas se aplican a la combinación de amoxicilina con ácido clavulánico. La prueba de nitrocefina fue positiva solo en una cepa. Genotípicamente, dos cepas distantes genéticamente, aisladas de un mismo paciente fueron positivas para el gen ermB. No se encontró una relación estadísticamente significativa entre la resistencia fenotípica y la presencia de ARG en relación con la eritromicina (p> 0,05). Se concluyó que los aislamientos de E. faecalis de infecciones endodónticas persistentes mostraron fenotipos de resistencia a varios agentes antimicrobianos, todos los cuales fueron susceptibles a amoxicilina / ácido clavulánico. Se sugiere una evaluación periódica de la susceptibilidad a los antibióticos como una práctica importante para la vigilancia de la resistencia a los antibióticos en las cepas orales.

Vigilância da resistência a antibióticos contra o Helicobacter pylori na região do Biobío (Chile) em uma década / Antibiotic resistance surveillance of helicobacter pylori at the biobío region (chile) in a decade

ABSTRACT BACKGROUND: Helicobacter pylori infection in Chile remains as a public and private health-care system's challenge, with a prevalence of the infection over 70%. Nowadays, antibiotic treatment of the infection is mandatory to prevent the arising of severe associated diseases but failures in the eradication therapy mainly due to clarithromycin resistance has been observed worldwide and first line eradication therapy seems to be not effective anymore in several geographical areas. Thus, health-care systems are committed to maintain an epidemiological surveillance upon the evolution of the antibiotic resistance of this priority 2 pathogen. OBJECTIVE: This work reports a 10 years surveillance of the primary antibiotic resistance of H. pylori clinical isolates at the Biobío region-Chile, and the evolution of resistance toward amoxicillin, clarithromycin, levofloxacin, metronidazole, and tetracycline among the species. METHODS: H. pylori strains were investigated during the periods 2005-2007 (1435 patients analysed) and 2015-2017 (220 patients analysed) by inoculating a saline homogenate biopsy onto the surface of Columbia agar (Oxoid, Basingstoke, UK) - supplemented with 7% horse red blood cells plus DENT inhibitor (Oxoid, Basingstoke, UK) - following by incubation at 37ºC under 10% CO2 atmosphere for five days. Antibiotic resistance pattern of the isolates was assessed using the disk diffusion test in Müeller-Hinton agar supplemented with 7% horse red blood cells followed by incubation for further three days under 10% CO2 atmosphere. Statistical analysis was done using the SPSS v22 software and P values <0.05 were considered statistically significant. RESULTS: A total of 41% of 1435 patients were detected to be infected with H. pylori by bacteriological culture in 2005-2007 period, meanwhile 32.7% from 220 patients were also infected in 2015-2017 period. The clinical isolates of H. pylori are mostly susceptible to amoxicillin and tetracycline (both over 98% of strains), but less susceptible to levofloxacin in both periods analysed (over 79% of the strains). On the other hand, metronidazole continuous showing the highest score of resistant isolates (over 40% of resistant strains), although an 18% fewer resistant strains were observed in 2015-2017 period. Clarithromycin, the key antibiotic in eradication therapies, has an increased frequency of resistant strain isolated in the decade (22.5% in 2005-2007 and 29.2% in 2015-2017). Multidrug resistant strains (two, three and four antibiotics) were also detected in both periods with the highest scores for simultaneous resistance to clarithromycin-metronidazole (18%) and clarithromycin-metronidazole-levofloxacin (12.5%) resistant strains. According to gender, the isolates resistant to amoxicillin, clarithromycin and metronidazole were more frequent in female, with a specific increment in amoxicillin and clarithromycin resistance. CONCLUSION: The frequency of clarithromycin resistance (29.2%) detected in 2015-2017 suggests that conventional triple therapy is no longer effective in this region.

RESUMO CONTEXTO: A infecção por Helicobacter pylori no Chile permanece como um desafio do sistema de saúde público e privado, com prevalência da infecção acima de 70%. Hoje em dia, o tratamento antibiótico da infecção é obrigatório para prevenir o surgimento de graves doenças associadas, mas falhas na terapia de erradicação, principalmente devido à resistência à claritromicina, têm sido observadas em todo o mundo, e a terapia de erradicação de primeira linha parece não ser mais eficaz em várias áreas geográficas. Assim, os sistemas de saúde estão comprometidos em manter uma vigilância epidemiológica sobre a evolução da resistência aos antibióticos deste patógeno prioritário tipo 2. OBJETIVO: Este trabalho relata uma vigilância de 10 anos da resistência antibiótica primária de isolados clínicos de H. pylori na região do Biobío-Chile, e a evolução da resistência em relação à amoxicilina, claritromicina, levofloxacina, metronidazol e tetraciclina entre as espécies. MÉTODOS: As cepas de H. pylori foram investigadas durante os períodos 2005-2007 (1435 pacientes analisados) e 2015-2017 (220 pacientes analisados) inoculando uma biópsia de homogeneizado fisiológico na superfície do agar Columbia (Oxoid, Basingstoke, Reino Unido) - suplementado com 7% de glóbulos vermelhos do cavalo mais o inibidor de DENTE (Oxoid, Basingstoke, Reino Unido) - seguindo pela incubação em 37ºC a atmosfera de 10% de CO2 por cinco dias. O padrão de resistência aos antibióticos dos isolados foi avaliado utilizando-se o teste de difusão em disco em agar Müeller-Hinton suplementado com 7% de glóbulos vermelhos de cavalo seguidos de incubação por mais três dias a atmosfera de 10% de CO2. A análise estatística foi realizada utilizando-se o software SPSS V22 e os valores de P<0,5 foram considerados estatisticamente significantes. RESULTADOS: Um total de 41% dos 1435 pacientes foram detectados como contaminados por H. pylori pela cultura bacteriológica no período 2005-2007, ao mesmo tempo 32,7% de 220 pacientes foram contaminados igualmente no período 2015-2017. Os isolados clínicos de H. pylori são principalmente suscetíveis à amoxicilina e tetraciclina (tanto mais de 98% das cepas), mas menos suscetíveis à levofloxacina em ambos os períodos analisados (mais de 79% das cepas). Por outro lado, o metronidazol permaneceu mostrando a maior pontuação de resistentes isolados (mais de 40% de cepas resistentes), embora tenham sido observados 18% menos cepas resistentes no período de 2015-2017. A claritromicina, o antibiótico-chave em terapias de erradicação, tem uma frequência aumentada de cepa resistente isolada na década (22,5% em 2005-2007 e 29,2% em 2015-2017). Cepas multirresistentes (dois, três e quatro antibióticos) também foram detectadas em ambos os períodos com os maiores escores de resistência simultânea à claritromicina-metronidazol (18%) e claritromicina-metronidazol-levofloxacina (12,5%) cepas resistentes. De acordo com o sexo, os isolados resistentes à amoxicilina, claritromicina e metronidazol foram mais frequentes no sexo feminino, com incremento específico em amoxicilina e resistência à claritromicina. CONCLUSÃO: A frequência de resistência à claritromicina (29,2%) detectada em 2015-2017 sugere que a terapia tripla convencional não é mais efetiva nesta região.

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

Resumen 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.

Abstract 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.

Primary antibiotic resistance and its relationship with cagA and vacA genes in Helicobacter pylori isolates from Algerian patients

Abstract The epidemiology of Helicobacter pylori resistance to antibiotics is poorly documented in Africa and especially in Algeria. The aim of our study was to determine the antibiotic resistance rates, as well as its possible relationship with VacA and CagA virulence markers of isolates from Algerian patients. One hundred and fifty one H. pylori isolate were obtained between 2012 and 2015 from 200 patients with upper abdominal pain. Antimicrobial susceptibility testing was performed for amoxicillin, clarithromycin, metronidazole, ciprofloxacin, rifampicin and tetracycline. Molecular identification of H. pylori and the detection of vacA and cagA genes were performed using specific primers. We found that H. pylori was present in 83.5% of collected biopsies, 54.9% of the samples were cagA positive, 49.67% were vacA s1m1, 18.30% were vacA s1m2 and 25.49% were vacA s2m2. Isolates were characterized by no resistance to amoxicillin (0%), tetracycline (0%), rifampicin (0%), a high rate of resistance to metronidazole (61.1%) and a lower rate of resistance to clarithromycin (22.8%) and ciprofloxacin (16.8%). No statically significant relationship was found between vagA and cagA genotypes and antibiotic resistance results (p > 0.5) except for the metronidazole, which had relation with the presence of cagA genotype (p = 0.001).

Susceptibilidad antimicrobiana de microorganismos anaerobios aislados de infecciones endodónticas primarias a amoxicilina y metronidazol y su asociación con los parámetros clínicos: serie de casos / Antimicrobial susceptibility of anaerobic microorganisms isolated from primary endodontic infections to amoxicillin and metronidazole and its association with clinical parameters: case series

El objetivo de este estudio es describir la composición de la microbiota anaerobia estricta/aerotolerante en infecciones endodónticas primarias, su susceptibilidad antimicrobiana, y la asociación con los parámetros clínicos. Se tomaron muestras de siete pacientes con necrosis pulpar sintomática o asintomática. Se utilizaron técnicas para la conservación, cultivo, incubación e identificación de anaerobios estrictos/aerotolerantes. Para determinar la susceptibilidad antimicrobiana a amoxicilina y metronidazol, se utilizó el método de dilución en agar. Se aislaron un total de 32 cepas, 20 (62,5 %) fueron anaerobios estrictos/aerotolerantes, y 8 (25 %) anaerobios facultativos. El microorganismo anaerobio estricto/aerotolerante más frecuente fue Fusobacterium nucleatum, se aisló en tres casos, todos relacionados con algún tipo de dolor, y en dos casos estuvo relacionado con Prevotella spp. Se encontró una colonia de F. nucleatum resistente a amoxicilina y con producción de ß-lactamasa, y otra de F. nucleatum resistente a metronidazol. Una colonia de P. propionicum/avidus presentó resistencia intermedia a amoxicilina y con producción de ß-lactamasa. Se encontró la presencia de bacterias anaerobias estrictas/aerotolerantes en los pacientes con infecciones endodónticas primarias. Existen algunos microrganismos relacionados con algún tipo de dolor, como F. nucleatum y P. micra. Los hallazgos muestran presencia de F. nucleatum resistentes a los antimicrobianos evaluados.

The objective of this study is to describe the composition of the strict / aerotolerant anaerobic microbiota in primary endodontic infections, antimicrobial susceptibility, and the association with clinical variables. Samples were taken from seven patients with symptomatic or asymptomatic pulp necrosis. conservation techniques, cultivation, incubation and identification of strict / aerotolerant anaerobes. We used the agar dilution method to determine the antimicrobial susceptibility to amoxicillin and metronidazole. A total of 32 strains, 20 (62.5 %) were isolated were strict / aerotolerant anaerobes, and 8 (25 %) facultative anaerobe organisms. The strict anaerobe / more Fusobacterium nucleatum was frequently aerotolerant, it was isolated in three cases, all related to some type of pain, and in two cases it was related to Prevotella spp. a colony of F. nucleatum resistant to amoxicillin and ß-lactamase production was found, and another F. nucleatum resistant to metronidazole. A colony of P. propionicum / avidus presented intermediate amoxicillin and ß-lactamase producing resistance. Conclusions: the presence of strict anaerobic bacteria / aerotolerant in patients with primary endodontic infections was found. There is some related pain, as F. nucleatum and P. micra microorganisms. The findings show the presence of F. nucleatum resistant to the antimicrobial organisms evaluated.

Long-term evaluation of the antimicrobial susceptibility and microbial profile of subgingival biofilms in individuals with aggressive periodontitis

This study evaluates the antimicrobial susceptibility and composition of subgingival biofilms in generalized aggressive periodontitis (GAP) patients treated using mechanical/antimicrobial therapies, including chlorhexidine (CHX), amoxicillin (AMX) and metronidazole (MET). GAP patients allocated to the placebo (C, n = 15) or test group (T, n = 16) received full-mouth disinfection with CHX, scaling and root planning, and systemic AMX (500 mg)/MET (250 mg) or placebos. Subgingival plaque samples were obtained at baseline, 3, 6, 9 and 12 months post-therapy from 3–4 periodontal pockets, and the samples were pooled and cultivated under anaerobic conditions. The minimum inhibitory concentrations (MICs) of AMX, MET and CHX were assessed using the microdilution method. Bacterial species present in the cultivated biofilm were identified by checkerboard DNA-DNA hybridization. At baseline, no differences in the MICs between groups were observed for the 3 antimicrobials. In the T group, significant increases in the MICs of CHX (p < 0.05) and AMX (p < 0.01) were detected during the first 3 months; however, the MIC of MET decreased at 12 months (p < 0.05). For several species, the MICs significantly changed over time in both groups, i.e., Streptococci MICs tended to increase, while for several periodontal pathogens, the MICs diminished. A transitory increase in the MIC of the subgingival biofilm to AMX and CHX was observed in GAP patients treated using enhanced mechanical therapy with topical CHX and systemic AMX/MET. Both protocols presented limited effects on the cultivable subgingival microbiota.

Antimicrobial resistance of Helicobacter pylori strains to five antibiotics, including levofloxacin, in Northwestern Turkey

INTRODUCTION: Antibiotic resistance is the main factor that affects the efficacy of current therapeutic regimens against Helicobacter pylori. This study aimed to determine the rates of resistance to efficacy clarithromycin, amoxicillin, tetracycline, levofloxacin and metronidazole among H. pylori strains isolated from Turkish patients with dyspepsia. METHODS: H. pylori was cultured from corpus and antrum biopsies that were collected from patients with dyspeptic symptoms, and the antimicrobial susceptibility of H. pylori was determined using the E-test (clarithromycin, amoxicillin, tetracycline, metronidazole and levofloxacin) according to the EUCAST breakpoints. Point mutations in the 23S rRNA gene of clarithromycin-resistant strains were investigated using real-time PCR. RESULTS: A total of 98 H. pylori strains were isolated, all of which were susceptible to amoxicillin and tetracycline. Of these strains, 36.7% (36/98) were resistant to clarithromycin, 35.5% (34/98) were resistant to metronidazole, and 29.5% (29/98) were resistant to levofloxacin. Multiple resistance was detected in 19.3% of the isolates. The A2143G and A2144G point mutations in the 23S rRNA-encoding gene were found in all 36 (100%) of the clarithromycin-resistant strains. Additionally, the levofloxacin MIC values increased to 32 mg/L in our H. pylori strains. Finally, among the clarithromycin-resistant strains, 27.2% were resistant to levofloxacin, and 45.4% were resistant to metronidazole. CONCLUSIONS: We conclude that treatment failure after clarithromycin- or levofloxacin-based triple therapy is not surprising and that metronidazole is not a reliable agent for the eradication of H. pylori infection in Turkey. .

Hidradenite supurativa (acne inversa): revisão da literatura e relato de caso sobre o tratamento cirúrgico de lesão pré-esternal / Hidradenitis suppurativa (acne inversa): review of the literature and case report on the surgical treatment of a presternal lesion

A Hidradenite Supurativa é uma doença crônica debilitante, estigmatizante e de difícil tratamento. A doença apresenta várias características clínicas, podendo ocorrer isolada ou simultaneamente em diversas localizações, geralmente simétricas, distribuídas na "linha do leite". Afeta a pele onde há maior quantidade de glândulas apócrinas intertriginosas, em ordem decrescente: axilas, região ano-genital, aréolas e sulco inframamário. Seu curso insidioso inicia com nódulos subcutâneos que se rompem e/ou coalescem, formando abscessos na derme profunda, extremamente doloridos. As lesões frequentemente drenam exudato purulento fétido, com importante prejuízo à qualidade de vida. Com a progressão da doença, ocorre formação de fistulas, comedões, fibrose, contraturas dérmicas e endurecimento da pele. Suas maiores chances de cura estão no diagnóstico precoce e tratamento individualizado, que abrange medidas farmacológicas, comportamentais e cirúrgicas. O tratamento cirúrgico tem sido considerado a medida curativa mais efetiva. A decisão entre as diversas modalidades vai depender do estágio, apresentação e comprometimento local e incluem incisão e drenagem dos abscessos, deroofing, marsupialização, eletrocirurgia, laser Nd:YAG, laser de CO2 e excisão cirúrgica extensa. As opções de reconstrução incluem cicatrização por segunda intenção, enxerto de pele total imediato ou tardio, fechamento primário e retalhos. O caso relatado de lesões préesternais apresentava características clínicas e histológicas compatíveis com HS, sendo esta uma localização incomum na Literatura. O resultado pós-operatório da ressecção de toda a lesão com fechamento primário mostrou-se resolutivo após longo tempo de seguimento. Mais ensaios clínicos randomizados são necessários para estipular o melhor manejo na HS.

Hidradenitis suppurativa is a chronic debilitating and stigmatizing disease that is difficult to treat. The disease presents several clinical characteristics, which may occur alone or simultaneously in various locations, generally symmetrical and distributed in the "milk line". It affects the following areas of the skin where intertriginous apocrine glands are numerous, in the descending order: axilla, anogenital region, areolas, and inframammary crease. Its insidious progression begins with formation of subcutaneous nodules that rupture and/or coalesce, forming extremely painful abscesses in the deep dermis. The lesions often drain foul purulent exudate, with significant damage to quality of life. As the disease progresses, formation of fistulas, comedones, fibrosis, dermal contractures, and hardening of the skin occur. The highest chances of cure are lie in early diagnosis and individualized treatment, which covers pharmacological, behavioral, and surgical measures. Surgical treatment has been considered a more effective curative measure. The decision between the different modalities will depend on the stage, presentation, and local commitment and include incision and drainage of abscesses, deroofing, marsupialization, electrosurgery, Nd:YAG laser, CO2 laser, and extensive surgical excision. The reconstruction options include healing by second intention, immediate or delayed full-thickness skin graft, primary closure, and flaps. The reported case of presternal injuries presented clinical and histological characteristics compatible with hidradenitis suppurativa; this location has been rarely reported in the literature. The postoperative results of complete resection of the lesion with primary closure indicated resolution over a long follow-up period. More randomized clinical trials are needed to determine the best management strategy for hidradenitis suppurativa.

RESISTANCE TO AMOXICILLIN, CLARITHROMYCIN AND CIPROFLOXACIN OF Helicobacter pylori ISOLATED FROM SOUTHERN BRAZIL PATIENTS / Resistência à amoxicilina, claritromicina e ciprofloxacina de Helicobacter pylori isolados de pacientes do Sul do Brasil

Introduction: Helicobacter pylori is a bacteria which infects half the world population and is an important cause of gastric cancer. The eradication therapy is not always effective because resistance to antimicrobials may occur. The aim of this study was to determine the susceptibility profile of H. pylori to amoxicillin, clarithromycin and ciprofloxacin in the population of Southern Brazil. Material and methods: Fifty four samples of H. pylori were evaluated. The antibiotics susceptibility was determined according to the guidelines of the British Society for Antimicrobial Chemotherapy and the Comité de l'Antibiogramme de la Société Française de Microbiologie. Results: Six (11.1%) H. pylori isolates were resistant to clarithromycin, one (1.9%) to amoxicillin and three (5.5%) to ciprofloxacin. These indices of resistance are considered satisfactory and show that all of these antibiotics can be used in the empirical therapy. Conclusion: The antibiotics amoxicillin and clarithromycin are still a good option for first line anti-H. pylori treatment in the population of Southern Brazil.

Introdução: Helicobacter pylori é uma bactéria que infecta metade da população mundial e é considerada importante causa de câncer gástrico. A terapia de erradicação nem sempre é eficaz, pois pode ocorrer a resistência aos antimicrobianos. Este estudo determinou a sensibilidade de H. pylori frente à amoxicilina, claritromicina e ciprofloxacina na população do Sul do Brasil. Material e métodos: Foram avaliadas 54 amostras de H. pylori. A sensibilidade aos antibióticos foi determinada segundo as orientações da British Society for Antimicrobial Chemotherapy e do Comité de l'Antibiogramme de la Société Française de Microbiologie. Resultados e discussão: Sete (13%) isolados de H. pylori foram resistentes à claritromicina, um (1,9%) à amoxicilina e três (5,5%) à ciprofloxacina. Estes índices são satisfatórios e demonstram que esses antibióticos podem ser utilizados na terapia empírica. Conclusão: Os antibióticos amoxicilina e claritromicina ainda são uma boa opção no tratamento de primeira linha anti-H. pylori na população do Sul do Brasil.

Estudo da ação antimicrobiana conjunta de extratos aquosos de Tansagem (Plantago major l, Plantaginaceae) e Romã (Punica granatum l, Punicaceae) e interferência dos mesmos na ação da amoxicilina in vitr / Study of the joint antimicrobial action of aqueous extracts of broadleaf plantain (Plantago major l, Plantaginaceae) and Pomegranate (Punica granatum l, Punicaceae) and their interference in the in vitro activity of amoxicillin

O uso de plantas medicinais no tratamento de doenças (fitoterapia) é uma prática de diversos povos, sendo realizada desde a Antiguidade. Diversos estudos são realizados para determinar a eficácia dessas plantas, sendo desconhecida a existência de interações e interferências na combinação das mesmas, quer seja benéfica, quer cause algum dano para o organismo. A fim de descobrir a existência dessas interações ou a interferência na ação do antibiótico amoxicilina testou-se Punica granatum e Plantago major contra as bactérias Staphylococcus aureus e Escherichia coli. A matéria prima foi obtida nas regiões de Montes Claros e Curvelo e seus extratos aquosos foi obtido através da decocção. A Concentração Inibitória Mínima (CIM) dos extratos foi determinada pela técnica de microdiluição em caldo. Para o teste de interferência realizou-se o teste de disco-difusão. No teste de microdiluição em caldo, Punica granatum apresentou CIM de 6,25% contra o S. aureus e de 25% contra E. coli. O extrato de Plantago major não apresentou atividade contra as bactérias. O teste de disco-difusão confirmou a existência de interações, sendo apenas quatro resultados significativos (Amoxicilina + Plantago major Pura (PgP), Amoxicilina + Plantago major Diluição 1 (PgD1) e Amoxicilia + Plantago major Diluição 2 (PgD2) contra E. coli e Amoxicilina + PgP contra S. aureus). Conclui-se que existe interação dos extratos entre si e dos extratos com a amoxicilina, o que também pode acontecer com outros antibióticos e gerar riscos para a população. Portanto é indispensável à realização de testes que complementem essa pesquisa oferecendo mais informação à população para segurança na utilização de plantas medicinais. informações à população assegurando sua segurança na utilização de plantas medicinais.

The use of medicinal plants in treating diseases (herbal medicine) is a practice of many peoples, being done since ancient times. Several studies are conducted to determine the effectiveness of these plants, but the existence of interactions and interference with their combined use, whether beneficial or detrimental to the body, are unknown. In order to discover the existence of these interactions or interferences in the activity of the antibiotic amoxicillin, we tested in this research Punica granatum and Plantago major against Staphylococcus aureus and Escherichia coli. The raw material was obtained in the regions of Montes Claros and Curvelo, and their aqueous extracts were obtained from decoction. The minimum inhibitory concentration (MIC) of the extracts was determined by the broth microdilution technique. For interference, we performed the disk diffusion test. In the broth microdilution test, Punica granatum had MICs of 6.25% against S.aureus and 25% against E. coli. The Plantago major extract showed no activity against the bacteria. The disk diffusion test confirmed the existence of interactions and only four significant results (amoxicillin + pure Punica granatum (PgP), amoxicillin + Punica granatum dilution 1 (PgD1) and amoxicillin + Punica granatum dilution 2 (PgD2) against E. coli and amoxicillin + PgP against S. aureus). We conclude, as a result, that there really is interaction between the extracts themselves and between the extracts and amoxicillin, which can also occur with other antibiotics and cause some risk to the population. Therefore, it is essential to carry out tests to complement this research, providing more information to the public and ensuring the safety in the use of medicinal plants.

Changes in the Eradication Rate of Conventional Triple Therapy for Helicobacter pylori Infection in Korea / 대한소화기학회지

Although, the prevalence of Helicobacter pylori infection in Korea has declined owing to the eradication therapy, recent seroprevalence of H. pylori infection is still reported to be as high as 54.4%. Until now, "standard regimen" for eradication of H. pylori has been conventional triple therapy consisting of proton pump inhibitor, amoxicillin, and clarithromycin. However, with the increase in antibiotic resistance, especially against clarithromycin, the eradication rate of conventional triple therapy has steadily declined during the past 13 years in Korea. Present eradication rate of standard triple therapy is reported to be less than 80%, which is the Maginot line of efficacy for the currently available regimen. Therefore, new first line eradication regimen is needed to enhance the eradication rate of H. pylori infection.

New Therapeutic Strategies against Helicobacter pylori / 대한소화기학회지

The standard therapy for Helicobacter pylori infection in Korea is a triple-drug regimen consisting of a proton pump inhibitor with two antibiotics such as clarithromycin, amoxicillin, and metronidazole. However, as the eradication rate of this regimen has declined over the past decade, this prompted the formulation of new therapeutic regimens. New therapeutic strategies against H. pylori infection that had been tried all over the world include sequential therapy, concomitant therapy, and tailored therapy This article will review the basic concepts and the results of previous clinical trials on the aforementioned new therapeutic regiments.

Evaluation of antimicrobial activity and cell viability of Aloe vera sponges

Background: Aloe vera L., member of the Liliaceae family, has been shown to stimulate cell proliferation and contribute to healing and angiogenesis, has anti-bacterial, anti-fungal and anti-inflammatory activity. In addition, Aloe vera can be used as a support for drug transport. Our objective is to evaluate antimicrobial activity and cytotoxicity of sponges of Aloe vera L. for use as a carrying support of drugs. Results: In this work, sponge of free Aloe vera (AV) loaded with amoxicillin (AMX) or nystatin (NYS) at 1% w/w, were prepared and physico-chemically characterized via X-ray diffraction, Fourier Transform Infrared Spectroscopy and thermal analysis. Antimicrobial potency of AV sponge alone, loaded with AMX or NYS, against strains of Streptococcus mutans, Staphylococcus aureus, Aggregatibacter actinomycetemcomitans, Enterococcus faecalis and Candida albicans was determined. Osteoblasts and human gingival fibroblasts were cultivated on AV, Aloe vera loaded with amoxicillin (AV/AMX) and Aloe vera loaded with nystatin (AV/NYS) and cellular viability was assessed. The physico-chemical characterization performed suggested that the loaded drugs were dispersed in the sponge and those interactions between the AV sponge and the loaded drugs were weak. Furthermore, AV loaded with AMX or NYS demonstrated antimicrobial potency and osteoblasts and fibroblasts were viable after 24 hrs on free AV, and AV loaded with AMX or NYS. Conclusions: Our results indicate that sponges of free AV, loaded with AMX or NYS, are biocompatible and exhibit antimicrobial activity.

Substitutions in Penicillin-Binding Protein 1 in Amoxicillin-Resistant Helicobacter pylori Strains Isolated from Korean Patients

BACKGROUND/AIMS: A worldwide increase in amoxicillin resistance in Helicobacter pylori is having an adverse effect on eradication therapy. In this study, we investigated the mechanism of the amoxicillin resistance of H. pylori in terms of amino acid substitutions in penicillin-binding protein 1 (PBP1). METHODS: In total, 150 H. pylori strains were isolated from 144 patients with chronic gastritis, peptic ulcers, or stomach cancer. The minimum inhibitory concentrations (MICs) of the strains were determined with a serial 2-fold agar dilution method. The resistance breakpoint for amoxicillin was defined as >0.5 microg/mL. RESULTS: Nine of 150 H. pylori strains showed amoxicillin resistance (6%). The MIC values of the resistant strains ranged from 1 to 4 microg/mL. A PBP1 sequence analysis of the resistant strains revealed multiple amino acid substitutions: Val16-->Ile, Val45-->Ile, Ser414-->Arg, Asn562-->Tyr, Thr593-->Ala, Gly595-->Ser, and Ala599-->Thr. The natural transformation of these mutated genes into amoxicillin-sensitive strains was performed in two separate pbp1 gene segments. A moderate increase in the amoxicillin MIC was observed in the segment that contained the penicillin-binding motif of the C-terminal portion, the transpeptidase domain. CONCLUSIONS: pbp1 mutation affects the amoxicillin resistance of H. pylori through the transfer of the penicillin-binding motif.

Sensibilidad in vitro a amoxicilina y claritromicina de Helicobacter pylori obtenido de biopsias gástricas de pacientes en zona de bajo riesgo para cáncer gástrico / Antimicrobial susceptibility of Helicobacter pylori with chronic gastritis

Introducción. La infección por Helicobacter pylori prevalece en más de la mitad de la población mundial. Es prioritario evaluar la sensibilidad actual in vitro de H. pylori a los antimicrobianos usados en los protocolos de erradicación, fundamentalmente para determinar los patrones y resolver la infección. Objetivo. Determinar la prevalencia de la infección y la sensibilidad antibiótica de H. pylori en biopsias gástricas. Materiales y métodos. Se investigan la prevalencia de la infección y la sensibilidad antibiótica de H. pylori de 203 pacientes con gastritis crónica procedentes de Tumaco (Nariño), mediante pruebas histopatológicas (escala Dixon) y microbiológicas (cultivo en agar sangre con suplemento de antibióticos) y, además, su resistencia a amoxicilina y claritromicina mediante el método de dilución en agar. Resultados. La prevalencia de la infección para H. pylori con pruebas histopatológicas y microbiológicas es de 88,7 % y 84,7 % respectivamente; la prevalencia de resistencia de H. pylori a amoxicilina y claritromicina y a ambos antibióticos, fue de 20,5 %, 19,8 % y 10,96 %, respectivamente. Conclusiones. Los resultados de este estudio indican que es alta la incidencia de H. pylori resistente a claritromicina y amoxicilina en pacientes de Tumaco con gastritis crónica. También, se encontraron cepas multirresistentes a claritromicina y amoxicilina.

Introduction. Infection by Helicobacter pylori is prevalent in approximately half the world´s population.However, the susceptibility of H. pylori to antimicrobial agents must be evaluated by in vitro methods in order to determine the susceptibility levels and to guide treatment regimes. Objective. The prevalence of infection and antibiotic susceptibility was evaluated in gastric biopsies containing H. pylori. Materials and methods. The prevalence of infection and antibiotic susceptibility was investigated in 203 patients with chronic gastritis from Tumaco, Colombia. Diagnosis was confirmed by histopathological evidence (Dixon scale) and microbiological (culture on blood agar supplemented with antibiotics).The antibiotic resistance of H. pylori was measured by its response toantimicrobial amoxicillin and clarithromycin using the agar dilution method. Results. The prevalence of infection for H. pylori with histopathological and microbiological tests was88.7% and 84.7% respectively. The prevalence of resistance of H. pylori to antimicrobial amoxicillin was 20.5%, to clarithromycin 19.8%, and to both antibiotics concurrently, 10.9%. Conclusions. A high incidence of clarithromycin-resistant and amoxicillin-resistant H. pylori was discovered in patients from Tumaco with chronic gastritis. Dual drug-resistant strains of H. pylori to clarithromycin and amoxicillin were also present.

Regional Difference of Antibiotic Resistance of Helicobacter pylori Strains in Korea / 대한소화기학회지

BACKGROUND/AIMS: This study was performed to compare the prevalence rates of primary antibiotic resistance in Helicobacter pylori (H. pylori) isolates among different regions of Korea. METHODS: H. pylori were isolated from gastric mucosal biopsy specimens of 99 Koreans who lived in Gyeonggi (n=40), Kangwon province (n=40) and Busan (n=19) from April to August in 2008. All the patients had no history of H. pylori eradication therapy. The susceptibilities of the H. pylori isolates to amoxicillin, clarithromycin, metronidazole, tetracycline, azithromycin, ciprofloxacin, levofloxacin, and moxifloxacin were tested according to the agar dilution method. RESULTS: There was a difference in resistance to clarithromycin in three institutes located among Gyeonggi (32.5%), Kangwon province (12.5%) and Busan (42.1%) by One way ANOVA test (p=0.027) and nonparametric Kruskal Wallis test (p=0.027). However, by post-hoc analysis, there was no statistically significant difference among three regions. Similarly, the other 7 antibiotics (amoxicillin, metronidazole, tetracycline, azithromycin, ciprofloxacin, levofloxacin and moxifloxacin) did not show any significant difference. CONCLUSIONS: There was no significant regional difference of the primary antibiotic resistance of H. pylori. However, the included patient number might not be enough for this conclusion demanding further evaluations.

Regional Difference of Antibiotic Resistance of Helicobacter pylori Strains in Korea / 대한소화기학회지

BACKGROUND/AIMS: This study was performed to compare the prevalence rates of primary antibiotic resistance in Helicobacter pylori (H. pylori) isolates among different regions of Korea. METHODS: H. pylori were isolated from gastric mucosal biopsy specimens of 99 Koreans who lived in Gyeonggi (n=40), Kangwon province (n=40) and Busan (n=19) from April to August in 2008. All the patients had no history of H. pylori eradication therapy. The susceptibilities of the H. pylori isolates to amoxicillin, clarithromycin, metronidazole, tetracycline, azithromycin, ciprofloxacin, levofloxacin, and moxifloxacin were tested according to the agar dilution method. RESULTS: There was a difference in resistance to clarithromycin in three institutes located among Gyeonggi (32.5%), Kangwon province (12.5%) and Busan (42.1%) by One way ANOVA test (p=0.027) and nonparametric Kruskal Wallis test (p=0.027). However, by post-hoc analysis, there was no statistically significant difference among three regions. Similarly, the other 7 antibiotics (amoxicillin, metronidazole, tetracycline, azithromycin, ciprofloxacin, levofloxacin and moxifloxacin) did not show any significant difference. CONCLUSIONS: There was no significant regional difference of the primary antibiotic resistance of H. pylori. However, the included patient number might not be enough for this conclusion demanding further evaluations.

Functional changes of dendritic cells in hypersensivity reactions to amoxicillin

A better understanding of dendritic cell (DC) involvement in responses to haptenic drugs is needed, because it represents a possible approach to the development of an in vitro test, which could identify patients prone to drug allergies. There are two main DC subsets: plasmacytoid DC (pDC) and myeloid DC (mDC). β-lactams form hapten-carrier conjugates and may provide a suitable model to study DC behavior in drug allergy reactions. It has been demonstrated that drugs interact differently with DC in drug allergic and non-allergic patients, but there are no studies regarding these subsets. Our aim was to assess the functional changes of mDC and pDC harvested from an amoxicillin-hypersensitive 32-year-old woman who experienced a severe maculopapular exanthema as reflected in interleukin-6 (IL-6) production after stimulation with this drug and penicillin. We also aim to demonstrate, for the first time, the feasibility of this method for dendritic cell isolation followed by in vitro stimulation for studies of drug allergy physiopathology. DC were harvested using a double Percoll density gradient, which generates a basophil-depleted cell (BDC) suspension. Further, pDC were isolated by blood DC antigen 4-positive magnetic selection and gravity filtration through magnetized columns. After stimulation with amoxicillin, penicillin and positive and negative controls, IL-6 production was measured by ELISA. A positive dose-response curve for IL-6 after stimulation with amoxicillin and penicillin was observed for pDC, but not for mDC or BDC suspension. These preliminary results demonstrate the feasibility of this methodology to expand the knowledge of the effect of dendritic cell activation by drug allergens.

La resistencia a antibióticos en Helicobacter pylori / The resistance to antibiotics in Helicobacter pylori

Se hizo una revisión sobre el tema de la resistencia a antibióticos en Helicobacter pylori dirigida a especialistas de la salud, particularmente a los gastroenterólogos. Se sabe que la actualización constante resulta una importante herramienta para combatir la infección por H. pylori y evitar el aumento de la resistencia del microorganismo a los antibióticos de elección en nuestro país. Se abordaron los mecanismos moleculares de acción de los antibióticos más empleados en las terapias erradicadoras (metronidazol, amoxicilina, tetraciclina y claritromicina); así como los genes del microorganismo involucrado en la resistencia a cada antibiótico. Se aportaron datos sobre otros antibióticos menos usados, como la levofloxacina y ciprofloxacina. Se incluyeron, además, los métodos más usados para detectar la resistencia de la bacteria a cada antibiótico.

A review on the topic of resistance to antibiotics in Helicobacter pylori directed to health specialists and, particularly, to gastroenterologists was made. It is known that the constant updating is an important tool to fight H. pylori infection and to prevent the increase of the resistance of the microorganism to election antibiotics in our country. The mollecular mechanisms of action of the antibiotics most commonly used in erradication therapies (metronidazole, amoxicillin, tetracycline and claritromicine), as well as the genes of the microorganism involved in the resistance to every antibiotic, were approached. Data on other less used antibiotics, such as levofloxacin and ciprofloxacin were given. The most used methods to detect the resistance of the bacterium to each antibiotic were also included.

Inhibitory activity of garlic (Allium sativum) extract on multidrug-resistant Streptococcus mutans.

Garlic (Allium sativum) extract has been known to have inhibitory activity on various pathogenic bacteria, viruses and fungi. The objective of present investigation was to study in vitro inhibitory activity of garlic extract on multidrug-resistant (MDR) strains of Streptococcus mutans isolated from human carious teeth. Filter sterilized aqueous extract of garlic was prepared and used in the present study. For isolation of S. mutans, extracted human carious teeth were cultured in Todd-Hewit broth and Mitis-Salivarius-Bacitracin agar. S. mutans was characterized by colony morphology, biochemical tests and other conventional bacteriological procedures. Disk sensitivity tests and broth dilution methods were used to determine antibiotic sensitivity profile and inhibitory activity of garlic extract on S. mutans isolated from carious teeth. Of 105 carious teeth tested, 92 (87.6%) isolates of S. mutans were recovered, among which 28 (30.4%) were MDR since they were resistant to four or more antibiotics. The highest rate of resistance was observed for tetracycline (30.4%) and least resistance (0%) to teichoplanin and vancomycin while 22.8% and 23.9% of the isolates were resistant to penicillin and amoxicillin, respectively. Chlorhexidine minimum inhibitory concentration (MIC) for MDR and non-MDR S. mutans varied from 2 to 16 microg ml(-1) and from 0.25 to 1 microg ml(-1), respectively (P<0.05). All isolates, MDR and non-MDR of S. mutans were sensitive to garlic extract with the MIC ranging from 4 to 32 microg ml(-1). Considering in vitro data obtained in the present study, mouthwashes or toothpaste containing optimum concentration of garlic extract could be used for prevention of dental caries.