Distribution of Aspergillus species and prevalence of azole resistance in clinical and environmental samples from a Spanish hospital during a three-year study period.

BACKGROUND: Surveillance studies are crucial for updating trends in Aspergillus species and antifungal susceptibility information. OBJECTIVES: Determine the Aspergillus species distribution and azole resistance prevalence during this 3-year prospective surveillance study in a Spanish hospital. MATERIALS AND METHODS: Three hundred thirty-five Aspergillus spp. clinical and environmental isolates were collected during a 3-year study. All isolates were screened for azole resistance using an agar-based screening method and resistance was confirmed by EUCAST antifungal susceptibility testing. The azole resistance mechanism was confirmed by sequencing the cyp51A gene and its promoter. All Aspergillus fumigatus strains were genotyped using TRESPERG analysis. RESULTS: Aspergillus fumigatus was the predominant species recovered with a total of 174 strains (51.94%). The rest of Aspergillus spp. were less frequent: Aspergillus niger (14.93%), Aspergillus terreus (9.55%), Aspergillus flavus (8.36%), Aspergillus nidulans (5.37%) and Aspergillus lentulus (3.28%), among other Aspergillus species (6.57%). TRESPERG analysis showed 99 different genotypes, with 72.73% of the strains being represented as a single genotype. Some genotypes were common among clinical and environmental A. fumigatus azole-susceptible strains, even when isolated months apart. We describe the occurrence of two azole-resistant A. fumigatus strains, one clinical and another environmental, that were genotypically different and did not share genotypes with any of the azole-susceptible strains. CONCLUSIONS: Aspergillus fumigatus strains showed a very diverse population although several genotypes were shared among clinical and environmental strains. The isolation of azole-resistant strains from both settings suggest that an efficient analysis of clinical and environmental sources must be done to detect azole resistance in A. fumigatus.

Summation of peaks and L34 ribosomal protein in the presence and absence of antibiotics enables susceptibility testing using MALDI-TOF mass spectrometry in 2h from Escherichia coli-positive blood cultures.

INTRODUCTION: We have developed a MALDI-TOF-mediated phenotypic method, which determines antibiotic susceptibility (AS) from positive blood cultures (BCs) in 2h. We developed a software for process automation. We report results on Escherichia coli-positive BCs with cefotaxime (CTX) and ciprofloxacin (CIP). METHODS: We studied CIP and CTX activity in 18 and 17 real E. coli-positive BCs, and in 56 and 45 spiked BCs, respectively. Positive BCs were incubated for 2h without any antibiotics, and with 2mg/l and 4mg/l of CIP and CTX. The extraction was performed using ethanol/formic acid. Spectra were processed with specifically developed software which compares the peaks' intensity and the size of specific peaks. RESULTS: The set cut-off point was a 3-fold decrease in the summation of all peaks and/or the 5382m/z peak value (ribosomal protein L34). In simulated BCs, the correlation of CIP 2mg/l and 4mg/l with Etest® was 94.6% and 98.2%, respectively; for CTX 2mg/l and 4mg/l, this correlation was 95.6%. In real BCs, the correlations were 100% for CIP (2mg/l and 4mg/l) and 88.2% and 94.1% for CTX 2mg/l and 4mg/l, respectively. Resistant isolates were always correctly classified. CONCLUSION: This method provides accurate, fast and inexpensive AS information. The method can be automated, making it easier to implement in a microbiology laboratory routine.

Fast methods of fungal and bacterial identification. MALDI-TOF mass spectrometry, chromogenic media. / Métodos rápidos de identificación de bacterias y hongos. Espectrometría de masas MALDI-TOF, medios cromogénicos.

MALDI-TOF mass spectrometry is now a routine resource in Clinical Microbiology, because of its speed and reliability in the identification of microorganisms. Its performance in the identification of bacteria and yeasts is perfectly contrasted. The identification of mycobacteria and moulds is more complex, due to the heterogeneity of spectra within each species. The methodology is somewhat more complex, and expanding the size of species libraries, and the number of spectra of each species, will be crucial to achieve greater efficiency. Direct identification from blood cultures has been implemented, since its contribution to the management of severe patients is evident, but its application to other samples is more complex. Chromogenic media have also contributed to the rapid diagnosis in both bacteria and yeast, since they accelerate the diagnosis, facilitate the detection of mixed cultures and allow rapid diagnosis of resistant species.

Screening for parasite infections in immigrant children from low-income countries.

INTRODUCTION: In Spain, minors represent approximately 20% of the immigration flow. Many of these immigrants come from countries in the tropics and sub-tropics where intestinal parasitic infections caused by helminths and protozoa are one of the major causes of human disease. The main objective of the present work was to describe parasite infections in a group of immigrant children. METHODS: A prospective evaluation was performed in 373 minors from Sub-Saharan Africa, North Africa, and Latin America. Details were collected from the medical records and physical examination. Urine, stool and peripheral blood samples were obtained for serological and routine laboratory tests. Direct and indirect parasitological tests were also performed. RESULTS: At least 1 parasitic disease was diagnosed in 176 (47.1%) immigrant children, while 77 (20.6%) minors were infected with two or more parasites. The number of parasites was highest in children from Sub-Saharan Africa compared with the rest of the areas of origin (p<.001), and in children from urban areas compared with those from rural areas (OR 1.27 [1.059-1.552], p=.011). The most frequent causes of multiple parasite infection were filariasis plus strongyloidiasis and filariasis plus schistosomiasis. Intestinal parasite infection was diagnosed in 38 cases (13.8%). Logistic regression analysis revealed that for each month of stay, the probability of a positive finding in the stool sample decreased by 0.02% [ß=-0.020, (p=.07)]. CONCLUSIONS: The high infection rates of parasite diseases in immigrant children point to the need for screening protocols for certain infectious diseases in these children according to their country of origin and their length of residence in Spain.

[Epidemiology of Clostridium difficile-associated disease (CDAD) in Salamanca]. / Epidemiología de la Enfermedad Asociada a Clostridium difficile (EACD) en Salamanca.

INTRODUCTION: Clostridium difficile infection is considered a major cause of nosocomial diarrhoea in developed countries and is increasingly becoming more important as an etiologic agent of community diarrhoea, also in patients without risk factors. METHOD: Beginning in May 2011, the aim of our study is to know the characteristics of patients suffering from C. difficile Associated Disease in Salamanca University Hospital, collecting their data in a survey conducted for this purpose. A case was defined as a patient with compatible clinical and positive microbiological diagnosis. RESULTS: After 18 months of study, 41 cases had been documented representing an incidence of 1.15 cases per 10,000 patient-days. Patients were hospitalized (37) or health care associated (4), females (54%), age ≥ 65 years (56%) with prior antibiotic treatment (80%), most had diarrhea after the third day of admission, less than three weeks and without blood. Most were treated with metronidazole alone (78%), 19% with metronidazole and vancomycin, and the remaining percentage was resolved without treatment. Recurrences were about 20% and 7 (17%) died. CONCLUSIONS: The characteristics of our patients with C. difficile - associated disease are the same as those reported by other authors. Local surveillance is important in order to study the endemic and epidemic C. difficile infection. According to published epidemiological changes, we should be able to develop strategies from the Microbiology laboratories that will improve diagnosis of the disease.