Pilar Marín-Casanova

Microbiological Characteristics and Susceptibility Patterns of Strains of Rhodotorula Isolated from Clinical Samples

The members of the genus Rhodotorula show a marked ubiquity. In man, they have been isolated from faeces, nails, skin, sputum, digestive tract and adenoids, forming part of the normal human flora, although in recent years cases have been reported of both local and systemic infection by this yeast. There are virtually no studies in the literature on the sensitivity of this genus to the antifungal agents in common clinical use. Therefore, it is considered of interest to study the microbiological characteristics and the susceptibility patterns of Rhodotorula isolated from clinical samples. A total of 35 different strains of Rhodotorula were studied. In vitro susceptibility testing to 5-fluorocytosine, amphotericin B, ketoconazole, fluconazole and itraconazole was performed. All the strains were considered sensitive to 5-fluorocytosine, amphotericin B, ketoconazole and itraconazole and resistant to fluconazole. As a conclusion, we can state that all the antifungal agents tested, except fluconazole, are useful medicaments for the treatment of infections by the Rhodotorula genus.

Diversity of bla genes and low incidence of CTX-M in plasmid-mediated AmpC-producing Escherichia coli clinical isolates

The aim of this study was to characterize plasmid‐mediated AmpC (pAmpC)‐producing Escherichia coli clinical isolates. A total of 101 strains with AmpC‐susceptibility pattern were prospectively included. All isolates were tested by multiplex PCR to detect different bla genes. Phylogenetic groups were determined by a multiplex PCR assay. Antimicrobial susceptibility was tested by a microdilution commercial method. Presence of blapAmpC was detected in 79 (78.2%) of the strains; in these pAmpC‐producing isolates, blaTEM was detected in 41 (51.9%) strains, blaSHV in 5 (6.3%) strains, blaOXA in 3 (3.8%) strains, and blaCTX‐M in 3 (3.8%) strains. blaVIM and blaKPC were detected in one strain. Sixteen strains belonged to phylogroup A, 27 to B1, 20 to B2, and 16 to D. As conclusion, the majority of the strains of E. coli with AmpC‐susceptibility pattern are pAmpC positive, although the association of extended‐spectrum beta‐lactamases (ESBL) and pAmpC is unusual.

First report of acute postoperative endophthalmitis caused by Rothia mucilaginosa after phacoemulsification

We aimed at reporting the first case of rapidly progressive acute postoperative endophthalmitis after phacoemulsification cataract surgery in an immunocompetent patient caused by Rothia mucilaginosa. An immunocompetent patient manifested endophthalmitis signs 48 hours after an uncomplicated cataract surgery by phacoemulsification. A bacteria of the family Micrococcaceae was cultured in the vitreous biopsy, namely R. mucilaginosa. The patient did not show a favorable clinical response after vitrectomy and systemic, intravitreal, and topical fortified antibiotics. The patient’s eye was very painful, and consequently, it deemed necessary to perform an evisceration. R. mucilaginosa may be an aggressive etiologic agent for postoperative endophthalmitis. Although the isolated R. mucilaginosa was susceptible to empirical treatment, it was impossible to control the infection with standard treatment, probably due to its ability to create a biofilm around the intraocular lens.

Direct identification of microorganisms from thioglycolate broth by MALDI-TOF MS

We developed an easy MALDI-TOF MS-based assay to identify microorganisms directly from thioglycolate broth. A total of 101 positive thioglycolate broths inoculated with 15 different kinds of samples were evaluated. In 91 samples (90.1%), direct MALDI-TOF MS identifications were the same as those obtained after conventional laboratory procedures including subcultures. In 10 samples misidentified by direct processing, yeasts or mixed cultures grew in the thioglycolate subcultures, or high cellular debris hampered a correct analysis. This rapid method can provide a fast, clinically- relevant species-level identification without disturbing the daily workflow in clinical microbiology laboratories.

Candida nivariensis as a New Emergent Agent of Vulvovaginal Candidiasis: Description of Cases and Review of Published Studies.

AbstractCandida nivariensis is a new emergent agent related to human infections in the vaginal tract and other localizations, but the phenotypic characteristics are very similar to Candida glabrata and can be misidentified and underdiagnosed. We described four cases of vulvovaginitis identified by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry and confirmed the results with PCR amplification and sequencing of the entire ITS genomic region (ITS1, ITS2 and 5.8 rRNA). We reinforce the need for new diagnostic tools for the correct identification of yeast infections.