Prospective comparative multi-centre study on imported Plasmodium ovale wallikeri and Plasmodium ovale curtisi infections

BACKGROUND

Few previous retrospective studies suggest that Plasmodium ovale wallikeri seems to have a longer latency period and produces deeper thrombocytopaenia than Plasmodium ovale curtisi. Prospective studies were warranted to better assess interspecies differences.

METHODS

Patients with imported P. ovale spp. infection diagnosed by thick or thin film, rapid diagnostic test (RDT) or polymerase chain reaction (PCR) were recruited between March 2014 and May 2017. All were confirmed by DNA isolation and classified as P. o. curtisi or P. o. wallikeri using partial sequencing of the ssrRNA gene. Epidemiological, analytical and clinical differences were analysed by statistical methods.

RESULTS

A total of 79 samples (35 P. o. curtisi and 44 P. o. wallikeri) were correctly genotyped. Males predominate in wallikeri group (72.7%), whereas were 48.6% in curtisi group. Conversely, 74.3% of curtisi group were from patients of African ethnicity, whilst 52.3% of Caucasians were infected by P. o. wallikeri. After performing a multivariate analysis, more thrombocytopaenic patients (p = 0.022), a lower number of platelets (p = 0.015), a higher INR value (p = 0.041), and shorter latency in Caucasians (p = 0.034) were significantly seen in P. o. wallikeri. RDT sensitivity was 26.1% in P. o. curtisi and 42.4% in P. o. wallikeri. Nearly 20% of both species were diagnosed only by PCR. Total bilirubin over 3 mg/dL was found in three wallikeri cases. Two patients with curtisi infection had haemoglobin under 7 g/dL, one of them also with icterus. A wallikeri patient suffered from haemophagocytosis. Chemoprophylaxis failed in 14.8% and 35% of curtisi and wallikeri patients, respectively. All treated patients with various anti-malarials which included artesunate recovered. Diabetes mellitus was described in 5 patients (6.32%), 4 patients of wallikeri group and 1 curtisi.

CONCLUSIONS

Imported P. o. wallikeri infection may be more frequent in males and Caucasians. Malaria caused by P. o. wallikeri produces more thrombocytopaenia, a higher INR and shorter latency in Caucasians and suggests a more pathogenic species. Severe cases can be seen in both species. Chemoprophylaxis seems less effective in P. ovale spp. infection than in P. falciparum, but any anti-malarial drug is effective as initial treatment. Diabetes mellitus could be a risk factor for P. ovale spp. infection.

Ophthalmic Econazole Hydrogels for the Treatment of Fungal Keratitis

Econazole is a feasible alternative treatment in the management of fungal keratitis. Nevertheless, its low water solubility is considered the main limitation to the incorporation into ophthalmic formulations. In this work, econazole nitrate is solubilized by using cyclodextrins to achieve an optimum therapeutic concentration. Phase solubility diagrams suggest α-cyclodextrin as the most effective cyclodextrin and later the inclusion complex formed with this one was characterized in solution by 1D, 2D-NMR, and molecular modeling. Econazole-α-cyclodextrin inclusion complex was included in 2 types of ocular hydrogels: a natural polysaccharides ion-sensitive hydrogel and a hyaluronic acid hydrogel. Both of them show no ocular irritation in the hen's egg test on chorioallantoic membrane assay and a controlled econazole release over time. Permeability studies suggest that hydrogels do not modify the econazole nitrate permeability through bovine cornea in comparison with an econazole-α-cyclodextrin inclusion complex solution. Finally, ocular biopermanence studies performed using positron emission tomography show these hydrogels present a high retention time on the eye. Results suggest the developed formulations have a high potential as vehicles for the econazole topical ocular administration as fungal keratitis treatment.

High primary antibiotic resistance of Helicobacter Pylori strains isolated from dyspeptic patients: A prevalence cross-sectional study in Spain

BACKGROUND

The rate of H. pylori resistance to different antibiotics is increasing and determines the selection of eradication therapy. The aim of this study was to determine the resistance patterns of H. pylori strains in our area.

METHODS

Biopsies from gastric corpus for microbiological culture and antibiotic resistance were obtained in patients undergoing upper gastrointestinal endoscopy for dyspepsia. Selective Agar Pylori for isolation of the bacteria and Agar Mueller-Hinton supplemented with blood to test the sensitivity to antibiotics were used. Presence of H. pylori was confirmed using direct observation with phase-contrast microscopy and/or smears stained with acridine orange. In vitro bacterial susceptibility to amoxicillin, clarithromycin, rifampicin, tetracycline, metronidazole, and levofloxacin was tested using diffusion MIC test strips. Minimum inhibitory concentration values were determined based on the 6th version of the EUCAST (European Committee on Antimicrobial Susceptibility Testing) Clinical Breakpoint (2016).

RESULTS

Two hundred and seventeen patients were included (58.1% female, median age 64 years, range 25-92). H. pylori was identified in 108 patients (49.8%); culture and antibiogram were completed in 77 of them (71.3% of H. pylori-positive patients). The resistance rates were as follows: levofloxacin 38.7%, rifampicin 33.3%, metronidazole 27% and clarithromycin 22.4%. No case of amoxicillin or tetracycline resistance was identified. Dual clarithromycin-metronidazole resistance was observed in 10% of strains, whereas multiple drug-resistant was observed in 14.2%.

CONCLUSIONS

Resistance rate of H. pylori to antibiotics is high in the northwest of Spain. The high resistance to levofloxacin and clarithromycin advises against their wide empirical use of these antibiotics in eradication regimens.

[Scedosporium apiospermum brain abscess. Report of one case with literature review]

Scedosporium apiospermum is a fungus found in the soil and in contaminated water and commonly cause cutaneous infections and is a rare cause of central nervous system infection. Invasive infection is usually associated with immunosuppresion. The authors present a 73-year-old woman with chronic renal disease who presented with headache for 2 weeks. Computerized tomography scans revealed a ring-enhancing lesion in left temporal lobe. An urgent craniotomy was performed and the lesion was totally removed. The patient died 5 days later. Scedosporium apiospermum was isolated in the culture of the extirpated lesion. The authors review the previously reported cases of brain abscess for Scedosporium apiospermum.

Combined used of RAPD and touchdown PCR for epidemiological studies of Aspergillus fumigatus

INTRODUCTION

Aspergillus fumigatus is a filamentous fungus that acts as an opportunistic pathogen and has emerged as a major problem in immunosuppressed patients. Nosocomial outbreaks of aspergillosis are becoming more frequent, but their identification and epidemiological characterization is slow and difficult.

OBJECTIVE

Description of a fast, sensitive, specific method to identify and fingerprint A. fumigatus using methodology available in clinical laboratories.

METHODS

We studied several strains of A. fumigatus isolated from patients with invasive aspergillosis (n = 4), the hospital environment (n = 5) and reference cultures (n = 1), as well as other close phylogenetic fungal species from patients (n = 1), hospital environment (n = 6) and reference cultures (n = 1). A. fumigatus was identified by both touchdown PCR and conventional phenotyping methods. Genotyping was performed with random amplification of polymorphic DNA (RAPD) analysis, comparing the results from two primers (OPZ-19 and R-108) and different amplification protocols with regard to band resolution and reproducibility.

RESULTS

Touchdown PCR and phenotype results were identical. Best RAPD results were obtained with the R-108 primer and considerably longer ramp times between annealing and extension.

CONCLUSION

RAPD analysis is a fast, reliable tool for DNA fingerprinting. Patterns may be easier to repeat and interpret when longer ramp times are used. Touchdown PCR combined with RAPD analysis is a sensitive, accurate method for managing clinical outbreaks of Aspergillus fumigatus.