Infection with Clostridioides difficile ribotype 046 in a paediatric liver transplant patient.

Clostridioides difficile causes nosocomial diarrhoea associated with antibiotic use and immunodeficiency. Although the number of paediatric C. difficile infections (CDIs) has increased worldwide, there are few studies on the molecular characterization of strains causing CDIs among children. We report the clinical features and strain molecular characterization of a CDI in a female child with a history of liver transplantation at 7 months of age. This is the first report of the 046 ribotype causing paediatric diarrhoea.

The Adaptor Protein Myd88 Is a Key Signaling Molecule in the Pathogenesis of Irinotecan-Induced Intestinal Mucositis.

Intestinal mucositis is a common side effect of irinotecan-based anticancer regimens. Mucositis causes cell damage, bacterial/endotoxin translocation and production of cytokines including IL-1 and IL-18. These molecules and toll-like receptors (TLRs) activate a common signaling pathway that involves the Myeloid Differentiation adaptor protein, MyD88, whose role in intestinal mucositis is unknown. Then, we evaluated the involvement of TLRs and MyD88 in the pathogenesis of irinotecan-induced intestinal mucositis. MyD88-, TLR2- or TLR9-knockout mice and C57BL/6 (WT) mice were given either saline or irinotecan (75 mg/kg, i.p. for 4 days). On day 7, animal survival, diarrhea and bacteremia were assessed, and following euthanasia, samples of the ileum were obtained for morphometric analysis, myeloperoxidase (MPO) assay and measurement of pro-inflammatory markers. Irinotecan reduced the animal survival (50%) and induced a pronounced diarrhea, increased bacteremia, neutrophil accumulation in the intestinal tissue, intestinal damage and more than twofold increased expression of MyD88 (200%), TLR9 (400%), TRAF6 (236%), IL-1ß (405%), IL-18 (365%), COX-2 (2,777%) and NF-κB (245%) in the WT animals when compared with saline-injected group (P<0.05). Genetic deletion of MyD88, TLR2 or TLR9 effectively controlled the signs of intestinal injury when compared with irinotecan-administered WT controls (P<0.05). In contrast to the MyD88-/- and TLR2-/- mice, the irinotecan-injected TLR9-/- mice showed a reduced survival, a marked diarrhea and an enhanced expression of IL-18 versus irinotecan-injected WT controls. Additionally, the expression of MyD88 was reduced in the TLR2-/- or TLR9-/- mice. This study shows a critical role of the MyD88-mediated TLR2 and TLR9 signaling in the pathogenesis of irinotecan-induced intestinal mucositis.

Virulence factors and biofilm production by isolates of Bacteroides fragilis recovered from dog intestinal tracts.

Bacteroides fragilis colonizes dog guts both as a commensal and as an opportunistic pathogen. This study aims to evaluate virulence factors of 13 B. fragilis strains isolated from dog intestinal tracts and their ability for biofilm formation. Capsules were detected in all the evaluated strains. A total of 61.5% of all strains were biofilm producers. These attributes most likely play an important role in B. fragilis persistent colonization in the gut.

Zinc treatment ameliorates diarrhea and intestinal inflammation in undernourished rats.

BACKGROUND: WHO guidelines recommend zinc supplementation as a key adjunct therapy for childhood diarrhea in developing countries, however zinc's anti-diarrheal effects remain only partially understood. Recently, it has been recognized that low-grade inflammation may influence stunting. In this study, we examined whether oral zinc supplementation could improve weight, intestinal inflammation, and diarrhea in undernourished weanling rats. METHODS: Rats were undernourished using a northeastern Brazil regional diet (RBD) for two weeks, followed by oral gavage with a saturated lactose solution (30 g/kg) in the last 7 days to induce osmotic diarrhea. Animals were checked for diarrhea daily after lactose intake. Blood was drawn in order to measure serum zinc levels by atomic absorption spectroscopy. Rats were euthanized to harvest jejunal tissue for histology and cytokine profiles by ELISA. In a subset of animals, spleen samples were harvested under aseptic conditions to quantify bacterial translocation. RESULTS: Oral zinc supplementation increased serum zinc levels following lactose-induced osmotic diarrhea. In undernourished rats, zinc improved weight gain following osmotic diarrhea and significantly reduced diarrheal scores by the third day of lactose intake (p < 0.05), with improved jejunum histology (p < 0.0001). Zinc supplementation diminished bacterial translocation only in lactose-challenged undernourished rats (p = 0.03) compared with the untreated challenged controls and reduced intestinal IL-1ß and TNF-α cytokines to control levels. CONCLUSION: Altogether our findings provide novel mechanisms of zinc action in the setting of diarrhea and undernutrition and support the use of zinc to prevent the vicious cycle of malnutrition and diarrhea.

Virulence factors and biofilm production by isolates of Bacteroides fragilis recovered from dog intestinal tracts

Bacteroides fragilis colonizes dog guts both as a commensal and as an opportunistic pathogen. This study aims to evaluate virulence factors of 13 B. fragilis strains isolated from dog intestinal tracts and their ability for biofilm formation. Capsules were detected in all the evaluated strains. A total of 61.5% of all strains were biofilm producers. These attributes most likely play an important role in B. fragilis persistent colonization in the gut.

Effect of subinihibitory and inhibitory concentrations of Plectranthus amboinicus (Lour.) Spreng essential oil on Klebsiella pneumoniae.

We evaluated the antimicrobial activity and some mechanisms used by subinhibitory and inhibitory concentrations of the essential oil, obtained from leaves of Plectranthus amboinicus, against a standard strain of Klebsiella pneumoniae and 5 multiresistant clinical isolates of the bacteria. The minimal inhibitory concentration (MIC) and minimal bactericidal concentration (MBC), the rate of kill and the pH sensitivity of the essential oil were determined by microdilution tests performed in 96-well plates. Subinhibitory and inhibitory concentrations of the essential oil were tested in order to check its action on K. pneumoniae membrane permeability, capsule expression, urease activity and cell morphology. The MIC and MBC of the essential oil were 0.09±0.01%. A complete inhibition of the bacterial growth was observed after 2 h of incubation with twice the MIC of the essential oil. A better MIC was found when neutral or alkaline pH broth was used. Alteration in membrane permeability was found by the increase of crystal violet uptake when the bacteria were incubated with twice the MIC levels of the essential oil. The urease activity could be prevented when all the subinhibitory concentrations were tested in comparison to the untreated group (p<0.001). Alteration of the bacterial morphology besides inhibition of the capsule expression was verified by atomic force microscopy, and Anthony's stain method, respectively. Our data allow us to conclude that the essential oil of P. amboinicus can be a good candidate for future research.

Effects of Myrcia ovata Cambess., essential oil on planktonic growth of gastrointestinal microorganisms and biofilm formation of Enterococcus faecalis

The essential oil from the leaves of Myrcia ovata Cambess., commonly used in Brazil for the treatment of gastric illnesses, was screened for antimicrobial activity and action in the formation of microbial biofilms by Enterococcus faecalis. The oil was obtained by hydrodistillation using a clevenger-type system. Its chemical composition was analyzed using GC and GC-MS. Both MIC and MBC of the essential oil were determined by broth microdilution techniques and agar dilution method. The essential oil showed antimicrobial activity against E. faecalis, Escherichia coli, Pseudomonas aeruginosa, Salmonella choleraesuis, Staphylococcus aureus, Streptococcus pneumoniae and Candida parapsilosis. The results showed that the essential oil of M. ovata Cambess. was effective against the formation of biofilm by E. faecalis when compared with the control. Four volatile compounds, representing 92.1 percent of the oil, were identified and geranial was the major component (50.4 percent). At the best of our knowledge, this is the first report of the chemical composition and antimicrobial activity of the essential oil from leaves of M. ovata.

O oleo essencial de Lippia gracilis Schauer, Verbenaceae, em ratos diabeticos / The essential oil from Lippia gracilis Schauer, Verbenaceae, in diabetic rats

O óleo essencial das folhas de Lippia gracilis Schauer, Verbenaceae, foi examinado por CG e CG-MS. Quinze constituintes foram identificados, onde o carvacrol, p-cimeno e o γ-terpineno foram as substâncias majoritárias. No estudo in vitro, a solução a 5 por cento do óleo de L. gracilis Schauer apresentou atividade antibacteriana para Staphylococcus aureus isolado de úlcera infectada de paciente diabético. O estudo avaliou a atividade antibacteriana da solução a 5 por cento do óleo de L. gracilis Schauer em modelo experimental em diabetes utilizando ratos albinos Wistar machos com membro pélvico infectado com cepa de Staphylococcus aureus. No experimento foram utilizados 28 ratos Wistar distribuídos em quatro grupos (G1-branco, G2-controle negativo, G3-controle positivo, G4-teste) de sete ratos. Quando comparado o grupo G4 com G3, observou-se que a solução a 5 por cento promoveu uma redução nas CFU/mL após 24h da administração do inóculo (S.aureus sem L. gracilis Schauer 10(8) ± 313 versus S.aureus com L. gracilis Schauer 13,28 ± 4,03). Os resultados foram expressos através do cálculo da média±EPM) e análise de variança (ANOVA). A diferença entre a concentração inibitória mínima no estudo in vitro foi determinada pelo teste Turkey (p<0.05). O teste Newman-Keuls com nível de significância (p<0.05) foi utilizado para o cálculo dos resultados obtidos no experimento in vivo. A solução a 5 por cento do óleo essencial de Lippia gracilis Schauer apresentou boa atividade antibacteriana tanto no estudo in vivo como no in vitro.

The essential oil from Lippia gracilis Schauer (Verbenaceae) leaves was examined by GC and GC-MS. Fifteen constituents were identified. Carvacrol, p-cymene and γ-terpinene were found to be the major components. In the in vitro study, 5 percent solution of the Lippia gracilis Schauer oil presented antibacterial activity against Staphylococcus aureus isolated from diabetic patients with infected ulcers. The study evaluated the antibacterial activity of the 5 percent solution of the Lippia gracilis Schauer oil on the experimental model of diabetic adult male albino Wistar rats with leaft pelvic limb infected by Staphylococcus aureus strain. In this experiment, 28 diabetic Wistar rats were used, randomly distributed in four different groups of seven rats, (G1-white; G2-negative control; G3-positive control and G4-test). When comparing group G4 with G3, it was observed that the 5 percent solution presented a reduced CFU/mL level showing the antibacterial effect of the oil 24 hours after the administration of the inoculum (S .aureus without Lippia gracilis Schauer 108 ±313 versus S.aureus with Lippia gracilis Schauer 13.28±4.03). The results were expressed as mean±S.E.M. One-way analysis of the variance (ANOVA) was used. The differences between the minimum inhibitory concentration in vitro test were determined by the Tukey test (p<0.05). The Newman-Keuls test with level of significance (p<0.05) was used to measure the results in vivo. The findings have shown that 5 percent solution of the Lippia gracilis Schauer oil presented antibacterial activity in vitro and in vivo.

Effects of myrcia ovata cambess. Essential oil on planktonic growth of gastrointestinal microorganisms and biofilm formation of enterococcus faecalis.

The essential oil from the leaves of Myrcia ovata Cambess., commonly used in Brazil for the treatment of gastric illnesses, was screened for antimicrobial activity and action in the formation of microbial biofilms by Enterococcus faecalis. The oil was obtained by hydrodistillation using a clevenger-type system. Its chemical composition was analyzed using GC and GC-MS. Both MIC and MBC of the essential oil were determined by broth microdilution techniques and agar dilution method. The essential oil showed antimicrobial activity against E. faecalis, Escherichia coli, Pseudomonas aeruginosa, Salmonella choleraesuis, Staphylococcus aureus, Streptococcus pneumoniae and Candida parapsilosis. The results showed that the essential oil of M. ovata Cambess. was effective against the formation of biofilm by E. faecalis when compared with the control. Four volatile compounds, representing 92.1 % of the oil, were identified and geranial was the major component (50.4 %). At the best of our knowledge, this is the first report of the chemical composition and antimicrobial activity of the essential oil from leaves of M. ovata.

Association of free amino acids with caries experience and mutans streptococci levels in whole saliva of children with early childhood caries.

OBJECTIVE: The aim of the present study was to identify the free amino acid content in whole saliva of children with (CE) and without early childhood caries (CF) (ECC), correlating these findings with caries experience and mutans streptococci (MS) levels in saliva. DESIGN: Seventy-eight healthy children, both genders, 6-71 months age, were selected to participate in the study. Following examination for dmft scores calculation, unstimulated whole saliva was collected from all 78 participants, stored at -80 degrees C, and used for amino acid analysis, on a Biochem 20 plus amino acid analyzer. Stimulated whole saliva was collected from 52 children, transported, diluted and plated on MSB agar medium for detection of MS in cfu/mL. RESULTS: Forty different free amino acids were identified in whole saliva, with great variation in their concentration. A statistically significant relation was found between caries experience and the presence of free proline and glycine. While proline (p=0.0182) was more frequently absent in the CF group, the absence of glycine (p=0.0397) was more often observed in the CE group. In the presence of higher levels of MS, free glycine reduced the risk of experiencing dental caries (p=0.0419). Conversely, the presence of proline was found to increase the risk of experiencing the disease (p=0.0492). CONCLUSIONS: The presence of free proline and absence of free glycine in children with ECC, highly contaminated with MS, increased the chances of experiencing dental caries in the present population. Further studies are needed to better understand this phenomenon.

Comparative study of the microbial profile from bilateral canine otitis externa.

Fifty dogs with bilateral otitis externa were studied over a 10-month period. The exudates of both external ears were obtained, using sterile swabs, and microorganisms were isolated according to standard microbiological techniques. Antimicrobial susceptibility testing of Staphylococcus intermedius was done by the agar diffusion method. There was bacterial and/or fungal growth in all of the samples. These were all polymicrobial infections. Anaerobic bacteria were not isolated in any sample. The most common pathogens isolated were S. intermedius and Malassezia pachydermatis. A statistically significant difference (P < 0.05) was observed in the isolation pattern between the right and left ears in 34 of the 50 animals (68%). High resistance rates of S. intermedius strains to penicillin, ampicillin, erythromycin, tetracycline, and clindamycin were found. The results suggest that in bilateral canine otitis externa, each ear should be cultured separately and considered as separate units.

Correlation between Enterococcus faecalis biofilms development stage and quantitative surface roughness using atomic force microscopy.

Biofilms are assemblages of microorganisms and their associated extracellular products at an interface and typically with an abiotic or biotic surface. The study of the morphology of biofilms is important because they are associated with processes of biofouling, corrosion, catalysis, pollutant transformation, dental caries, drug resistance, and so forth. In the literature, biofilms have been examined by atomic force microscopy (AFM), which has proven to be a potent tool to study different aspects of the biofilm development on solid surfaces. In this work, we used AFM to investigate topographical changes during the development process of Enterococcus faecalis biofilms, which were generated on sterile cellulose nitrate membrane (CNM) filters in brain heart infusion (BHI) broth agar blood plates after 24, 36, 72, 192, and 360 h. AFM height images showed topographical changes due to biofilm development, which were used to characterize several aspects of the bacterial surface, such as the presence of extracellular polymeric substance, and the biofilm development stage. Changes in the development stage of the biofilm were shown to correlate with changes in the surface roughness as quantified through the mean roughness.

Effect of sodium alendronate on alveolar bone resorption in experimental periodontitis in rats.

BACKGROUND: Bisphosphonates are potent inhibitors of bone resorption and were shown to inhibit bone resorption in experimental periodontitis by unknown mechanisms. We studied the effect of the aminobisphosphonate sodium alendronate (SA) in experimental periodontitis. Wistar rats were subjected to ligature placement around the second upper left molars. METHODS: Animals were treated with SA 0.01 to 0.25 mg/kg subcutaneously (sc), either 1 hour before (prophylactic) or starting 5 days after (therapeutic) periodontitis induction and daily until the rats were sacrificed (11 days). Controls received saline. Animals were weighed daily. Alveolar bone loss was measured as the difference (in millimeters) between the cusp tip and the alveolar bone. The periodontium and the surrounding gingivae were examined at histopathology, and the neutrophil influx into the gingivae was assayed using myeloperoxidase activity. The local bacterial flora was assessed through culture of the gingival tissue in standard aerobic and anaerobic media. RESULTS: Alveolar bone loss was significantly and dose dependently inhibited by SA either as a prophylactic or therapeutic treatment compared to the control. SA reduced tissue lesion at histopathology, with partial preservation of the periodontium, coupled to decreased myeloperoxidase activity compared to the control. The reduced neutrophil influx was also shown in carrageenan-induced peritonitis, used as a control experiment for this parameter. SA also significantly inhibited the growth of pigmented bacilli and Fusobacterium nucleatum, which are important in the pathogenesis of periodontal disease. SA also inhibited the in vitro growth of isolated Peptostreptococcus sp. CONCLUSION: Sodium alendronate preserves alveolar bone resorption and has anti-inflammatory and antibacterial activities in experimental periodontitis.

Pé diabético: análise bacteriológica de 141 casos / Diabetic foot infection: bacteriologic analysis of 141 patients

Diabetes mellitus (DM) é uma doença progressiva que apresenta complicações freqüentes, em especial a infecção nos pés. Realizamos um estudo prospectivo com 141 pacientes com DM e úlceras infectadas nos pés, conduzido no Centro Integrado de Diabetes e Hipertensão da UFC no período de março/2000 a novembro/2001. A maioria apresentava infecção avaliada como graus I e II da classificação de Wagner. As amostras foram cultivadas utilizando-se meios seletivos, e a identificação bacteriana e os antibiogramas foram realizados através de metodologia convencional e automatizados. Os patógenos mais freqüentemente isolados foram as enterobactérias (83,7 por cento), Staphylococcus aureus (43,3 por cento) e bactérias anaeróbias (17 por cento). Cepas de Streptococcus pyogenes foram isoladas de 7,8 por cento dos pacientes. Cepas produtoras de beta-lactamase de espectro ampliado e cepas de Staphylococcus aureus resistentes à oxacilina foram isoladas de 6 por cento e 11,6 por cento dos pacientes, respectivamente. A resistência aos antimicrobianos vem se tornando cada vez mais comum, mesmo em pacientes com infecção adquirida na comunidade. Investimentos em diagnóstico etiológico das infecções e estratégias racionais no uso de antimicrobianos fazem-se necessários na tentativa de evitar tratamentos inadequados e suas já conhecidas conseqüências.

[Diabetic foot infection. Bacteriologic analysis of 141 patients]. / Pé diabético: análise bacteriológica de 141 casos.

Diabetes mellitus (DM) is a progressive disease with chronic complications. Feet problems represent one of the most important complications. In a prospective study, we analyzed 298 species of bacteria isolated from 141 patients with community-acquired diabetic foot ulcers. The study was undertaken at a diabetic center and at the Federal University of Ceará, Brazil, from March/2000 to November/2001. The majority of patients had mild to moderate infections and was classified as Wagner's grades I and II. The samples were cultured using selective media. The identification and the susceptibility tests were done by conventional and automated methods. The most frequently occurring pathogens were Enterobacteriaceae (83.7%), Staphylococcus aureus (43.3%) and anaerobic bacteria (17%). Streptococcus pyogenes was recovered from 7.8% of the patients. ESBL producing strains were detected in 6% and methicillin resistant Staphylococcus aureus strains were recovered from 11.6% of the patients. Resistance among bacteria has increased largely, and became common even in community-acquired infections. Improvements in the routine etiologic diagnostics and antibiotic use strategies are required to avoid inadequate treatment and its well known dramatic consequences.

Teste de sensibilidade a antimicrobianos: técnica de difusäo em ágar para Bacteroides resistentes à bile / Antimicrobial susceptibility testing: disk diffusion method for bile-resistance Bacteroides

Uma modificaçäo da técnica de difusäo em ágar de BARRY et al. (1970), para testar a sensibilidade de Bacteroides bile-resistentes a antimicrobianos, é sugerida neste trabalho. Foram utilizadas 101 amostras de bactérias anaeróbicas estritas isoladas de espécimes fecais e de nateriais clínicos de pacientes provenientes do Hospital Universitário Walter Cantídio da Universidade Federal do Ceará. Após caracterizaçäo a nível de gênero, a sensibilidade das cepas isoladas frente a penicilina G e clorafenicol foi determinada através da técnica da camada sobposta e da técnica de referência de diluiçäo em ágar. Os resultados encontrados foram comparados utilizando-se a análise de regressäo linear pelo método da "percentagem de erro ligada" de METZLER e DEHAAN. Uma boa correlaçäo entre as CIMs e os diâmetros dos halos de inibiçäo para pencilinaG foi encontrada. Para o cloranfenicol, a correlaçäo näo pode ser estabelecida, visto näo terem sido isoladas cepas resistentes a este antimicrobiano. A técnica proposta mostrou-se reproduzível para os antibióticos testados