In vitro effect photodynamic therapy with differents photosensitizers on cariogenic microorganisms.

BACKGROUND: Antimicrobial photodynamic therapy has been proposed as an alternative to suppress subgingival species. This results from the balance among Streptococcus sanguis, Streptococcus mutans and Candida albicans in the dental biofilm. Not all the photosensitizers have the same photodynamic effect against the different microorganims. The objective of this study is to compare in vitro the photodynamic effect of methylene blue (MB), rose Bengal (RB) and curcumin (CUR) in combination with white light on the cariogenic microorganism S. mutans, S. sanguis and C. albicans. RESULTS: Photodynamic therapy with MB, RB and CUR inhibited 6 log 10 the growth of both bacteria but at different concentrations: 0.31-0.62 µg/ml and 0.62-1.25 µg/ml RB were needed to photoinactivate S. mutans and S. sanguis, respectively; 1.25-2.5 µg/ml MB for both species; whereas higher CUR concentrations (80-160 µg/ml and 160-320 µg/ml) were required to obtain the same reduction in S. mutans and S. sanguis viability respectively. The minimal fungicidal concentration of MB for 5 log10 CFU reduction (4.5 McFarland) was 80-160 µg/ml, whereas for RB it ranged between 320 and 640 µg/ml. For CUR, even the maximum studied concentration (1280 µg/ml) did not reach that inhibition. Incubation time had no effect in all experiments. CONCLUSIONS: Photodynamic therapy with RB, MB and CUR and white light is effective in killing S. mutans and S. sanguis strains, although MB and RB are more efficient than CUR. C. albicans required higher concentrations of all photosensitizers to obtain a fungicidal effect, being MB the most efficient and CUR ineffective.

Photodynamic fungicidal efficacy of hypericin and dimethyl methylene blue against azole-resistant Candida albicans strains.

Antimicrobial photodynamic therapy (aPDT) is an emerging alternative to treat infections based on the use of photosensitisers (PSs) and visible light. To investigate the fungicidal effect of PDT against azole-resistant Candida albicans strains using two PSs with a different mechanism of action, hypericin (HYP) and 1,9-dimethyl methylene blue (DMMB), comparing their efficacy and the reactive oxygen species (ROS) species involved in their cytotoxicity. Azole-resistant and the azole-susceptible C. albicans strains were used. Solutions of 0.5 and 4 McFarland inoculum of each Candida strain were treated with different concentrations of each PS, and exposed to two light-emitting diode light fluences (18 and 37 J cm⁻²). Mechanistic insight was gained using several ROS quenchers. The minimal fungicidal concentration of HYP for ≥3 log10 CFU reduction (0.5 McFarland) was 0.62 µmol l⁻¹ for most strains, whereas for DMMB it ranged between 1.25 and 2.5 µmol l⁻¹. Increasing the fluence to 37 J cm⁻² allowed to reduce the DMMB concentration. Higher concentrations of both PSs were required to reach a 6 log10 reduction (4 McFarland). H2O2 was the main phototoxic species involved in the fungicidal effect of HYP-aPDT whereas ¹O2 was more important for DMMB-based treatments. aPDT with either HYP or DMMB is effective in killing of C. albicans strains independent of their azole resistance pattern. HYP was more efficient at low fungal concentration and DMMB at higher concentrations.

Detection and characterization of a ST6 clone of vanB2-Enterococcus faecalis from three different hospitals in Spain.

Thirteen vancomycin-resistant and teicoplanin-susceptible Enterococcus faecalis isolates were recovered from unrelated patients in three Spanish hospitals from November 2009 to December 2010. All isolates carried the vanB2 gene, showed indistinguishable or closely-related PFGE patterns and were ascribed to the sequence type ST6 (included into the high-risk clonal-complex CC2). They showed a multiresistance phenotype (erythromycin, tetracycline, ciprofloxacin and high-level-resistance to streptomycin, gentamicin and kanamycin) and harboured the aac(6')-aph(2"), ant(6)-Ia, and tet(M)+/-tet(L) genes. All isolates produced gelatinase and harboured the gelE gene, but not the esp or hyl genes. The inclusion of the vanB2 gene into the Tn5382 transposon was demonstrated in one isolate. Clonal dissemination of vanB2-containing the E. faecalis strain is demonstrated.

Tinea capitis caused by Trichophyton soudanense and Microsporum audouinii in an adult: a case report.

This report presents a rare case of tinea capitis caused by Trichophyton soudanense and Microsporum audouinii in a 31-year-old woman from Senegal. The patient showed atrophic skin lesions causing cicatricial alopecia, scarring being caused by two aetiological agents uncommon in Spain.

Cavitary pneumonia caused by nocardia otitidiscaviarum

We report a case of cavitary pneumonia caused by N. otitidiscaviarum in a man with diabetes mellitus and thrombocytopenia treated with systemic corticosteroid. Taxonomic identification involved phenotypic testing and molecular identification that was carried out by DNA sequencing of the 16SrRNA gene.

Cavitary pneumonia caused by Nocardia otitidiscaviarum.

We report a case of cavitary pneumonia caused by N. otitidiscaviarum in a man with diabetes mellitus and thrombocytopenia treated with systemic corticosteroid. Taxonomic identification involved phenotypic testing and molecular identification that was carried out by DNA sequencing of the 16SrRNA gene.

Successful treatment of chromoblastomycosis of 36 years duration caused by Fonsecaea monophora.

We report a case of chromoblastomycosis in a 67-year-old female farmer, which involved a large (20 x 30 cm) cicatricial erythematous plaque on the inner side of her right thigh. The lesion was initially a small nodule which gradually extended over 36 years. Direct microscopic examination revealed a granulomatous lesion with muriform cells surrounded by giant cells. The mould recovered in cultures was dark olivaceous and identified as Fonsecaea monophora by ribosomal internal transcribe spacer (ITS) sequence data. The lesion was successfully cured after 4 months treatment with itraconazole, but there was a relapse.

First Spanish case of nocardiosis caused by Nocardia takedensis.

Nocardia takedensis is a recently described species isolated from soil. The first clinical isolate in Japan has recently been reported. This report describes the first clinical isolate of N. takedensis in Spain from a respiratory specimen.

Is Rotavirus contributing to an increase of diarrhoea in a region of Spain?

Diarrhoeal illnesses are the most frequent of notifiable diseases in Aragon. Physicians notify diarrhoea cases with presumed infectious origin on a weekly basis. Following an increase in 2005-2006, we aimed to identify the responsible organism(s) in order to inform control measures. We described seasonality of diarrhoea notifications for 1998-2004 and 2005-2006. We calculated correlations between diarrhoea notifications and enteric pathogens diagnosed in two Aragonese laboratories, and applied linear regression using coefficients of determination (r2). In 2005-2006 the winter peak of diarrhoea notifications increased from 2494 to 3357 weekly cases (34.6%) and the peak in Rotavirus diagnoses from 15 to 39 weekly cases. The correlation of diarrhoea notifications with Rotavirus was 0.05 in 1998-2004 and 0.42 in 2005-2006. The model for 1998-2004 included Salmonella enterica, Giardia lamblia and Clostridium difficile (r2=0.08) and for 2005-2006 Rotavirus and Astrovirus (r2=0.24). Our results suggest that Rotavirus contributed to the increase of diarrhoea notifications. We recommend determining the disease burden of Rotavirus in order to guide vaccination policies.

Genotyping of Mycobacterium tuberculosis over two periods: a changing scenario for tuberculosis transmission.

OBJECTIVE: To evaluate changes in the molecular epidemiology of tuberculosis (TB) in Zaragoza, Spain, over a decade that has seen large social and health changes, including the attenuation of the human immunodeficiency virus (HIV) epidemic and increased immigration. DESIGN: A population-based molecular study was conducted using standard restriction fragment length polymorphism IS6110 typing that included all patients with bacteriologically confirmed TB living in the Zaragoza area from 2001 to 2004. The current situation was compared with that described in a previous study from 1993 to 1995. RESULTS: A total of 454 Mycobacterium tuberculosis isolates were genotyped; 239 (52.6%) were grouped in 45 clusters composed of 2 to 85 isolates. Independent risk factors for clustering were identified. The main differences with the previous study were the increase of TB cases among immigrants, a decrease in HIV-TB co-infected patients and the occurrence of a large TB outbreak involving 85 patients (M. tuberculosis Zaragoza [MTZ] strain). CONCLUSION: A change in the epidemiological pattern of TB has been observed in the last years. TB transmission is more common among the Spanish-born population, while foreign birth is significantly less associated with clustering. A single epidemic strain caused 18.7% of all TB cases.

Mycobacterium malmoense lymphadenitis in Spain: first two cases in immunocompetent patients.

Reported here are two cases of Mycobacterium malmoense lymphadenitis that occurred in two immunocompetent children in Spain. To the best of our knowledge, these are the first documented cases of extrapulmonary infection by M. malmoense in Spain. This report serves to draw attention to this emerging nontuberculous mycobacterium that is gaining increasing recognition as a pulmonary and extrapulmonary pathogen in different countries.

[Helicobacter pylori eradication in patients with peptic ulcer after two treatment failures: a prospective culture-guided study]. / Erradicación de Helicobacter pylori en pacientes con úlcera péptica tras fracaso de dos tratamientos previos: estudio prospectivo guiado por cultivo.

AIM: To determine the effectiveness of a third, culture-guided, treatment of H. pylori infection after two unsuccessful attempts. PATIENTS AND METHODS: Forty-two consecutive patients with a diagnosis of peptic ulcer were included in an open prospective and multicenter study. After two unsuccessful attempts at eradication (demonstrated by positive urea breath test), all patients underwent endoscopy and H. pylori infection was confirmed by urease test, histology and culture (Pylori-Agar, Bio Merieux, France). Antibiotic susceptibility to metronidazole, amoxicillin, tetracycline and clarithromycin was defined by E-test. Thirty-nine patients received a two-week quadruple culture-guided therapy defined by the protocol, which considered sensitivity data and previous allergies to antibiotics (one culture was contaminated, one patient refused treatment and one was allergic to tetracycline and amoxicillin and was resistant to metronidazole and clarithromycin). Compliance was monitored by pill counting and eradication was defined as a negative urea breath test six weeks after the end of treatment. RESULTS: Sensitivity data were obtained in 41 patients. Intention-to-treat analysis revealed that overall eradication was achieved in 60% (24/40). Eighteen strains (43.9%) were resistant to metronidazole, 21 (51.2%) were resistant to clarithromycin and 8 (19.5%) were resistant to both drugs. None of the strains were resistant to amoxicillin or tetracycline. We used mainly two kinds of quadruple therapy in the 39 patients. Despite good compliance with treatment based on omeprazole (20 mg/12 h), bismuth subcitrate (120 mg/6 h), tetracycline (500 mg/4 h) and clarithromycin (500 mg/ 12 h) (OBTC) eradication was achieved in only 9 of 19 patients (47.4%; CI: 24.4-71.1) (one patient failed to attend the urea breath test). Nineteen clarithromycin-resistant patients received amoxicillin (1,000 mg/12 h) instead of clarithromycin (OBTA) and this treatment was effective in 14 (73.7%; CI: 48.8-90.9). Eradication was achieved in one patient who was allergic to amoxicillin and resistant to clarithromycin and metronidazole and who received ciprofloxacin (500 mg/8 h) instead of clarithromycin (OBTCipro). No clinical factors associated with eradication failure were found. CONCLUSIONS: Despite the use of two-week, high-dose, quadruple and culture-guided combinations of drugs, a third treatment was frequently unsuccessful. The lowest eradication rate was obtained in patients with H. pylori strains sensitive to all antibiotics; therefore, we believe that other factors could influence eradication rates. New prospective and randomized studies are needed in this subgroup of patients to find effective treatments.

Third line treatment for Helicobacter pylori: a prospective, culture-guided study in peptic ulcer patients.

BACKGROUND: A third line treatment is needed in roughly 5% of patients infected with Helicobacter pylori. Few data have been reported on efficacy of treatment regimens in these patients. METHODS: A prospective trial was designed to study the effectiveness of third line treatment of H. pylori infection in ulcer patients. Two-week quadruple, culture-guided, combinations were used in 31 consecutive patients. Susceptibility to metronidazole and clarithromycin were studied by E-test, and thereafter a predetermined treatment regimen was used. Compliance was evaluated by pill count, and eradication defined by negative urea breath test at 6 weeks. RESULTS: Two main quadruple regimens were used in 29 patients. In spite of good compliance, the combination of omeprazole, tetracycline, bismuth and clarithromycin (OTBC) showed an eradication rate (per protocol analysis) of 36% (five out of 14; CI: 12.8-64.9), and if amoxycillin was used (OTBA) the rate was 67% (eight out of 12; CI: 34.9-90.1). The difference was not significant. No clinical factor was found to be associated with failure to eradicate. CONCLUSIONS: Third line treatment often fails to eradicate H. pylori infection. New strategies need to be developed and tested for this common clinical situation.

[Multidrug-resistant Salmonella a significant clinical problem?]. / Salmonella multirresistente: un problema clinico real?

The incidence of infections caused by Salmonella strains resistant to antibiotics, including ampicillin, chloramphenicol, streptomycin, sulfonamides, tetracycline and even amoxicyllin-clavulanate, is increasing. We present two cases that illustrate the potential severity of infections caused by multidrug-resistant Salmonella and also the difficulty of reaching a differential diagnosis with inflammatory bowel disease.