Adherence to infection control recommendations is critical to prevent spread of this novel yeast.

Knowledge of the environmental distribution of C. neoformans/C. gattii is important in the epidemiology and ecology of the etiological agent, which causes cryptococcosis, a deadly disease worldwide. The aim of this report is to describe the presence of C. neoformans/C. gattii in new environmental niches in Colombia. A total of 837 environmental samples were collected from six different species of trees across four cities; molecular type was determined by PCR fingerprinting and RFLP. Molecular type VNI and VGIII were isolated from different species of trees, resulting in two novel niches for this pathogen: Tabebuia guayacan and Roystonea regia.

Introduction: The average annual incidence of cryptococcosis in Colombia is 0.23 cases per 100,000 inhabitants in the general population, and 1.1 cases per 1000 in inhabitants with Acquired Immune Deficiency Syndrome (AIDS). In addition, the causal fungus has been isolated from the environment, with serotypes A-B and C in different regions. This study aims to determine the genetic association between clinical and environmental isolates of C. neoformans/C. gattii in Colombia. Methods: Multilocus sequence typing (MLST) was used to identify possible clones, providing information about the epidemiology, ecology, and etiology of this pathogen in Colombia. Results: A total of 110 strains, both clinical (n=61) and environmental (n=49), with 21 MLST sequence types (ST) of C. neoformans (n =14STs) and C. gattii (n=7STs) were identified. The STs which shared clinical and environmental isolate sources were grouped in different geographical categories; for C. neoformans, ST93 was identified in six departments, ST77 in five departments; and for C. gattii, ST25 was identified in three departments and ST79 in two. Conclusions: High genetic diversity was found in isolates of C. neoformans/gattii by MLST, suggesting the presence of environmental sources harboring strains which may be sources of infection for humans, especially in immunocompromised patients; these data contribute to the information available in the country on the distribution and molecular variability of C. neoformans and C. gattii isolates recovered in Colombia.

The environmental isolation of Cryptococcus spp. is typically a difficult undertaking. Collecting samples in the field is costly in terms of travel, personnel time and materials. Furthermore, the recovery rate of Cryptococcus spp. may be very low, thereby requiring a large number of samples to be taken without any guarantee of success. Ecological niche modeling is a tool that has traditionally been used to forecast the distribution of plant and animal of species for biodiversity and conservation purposes. Here, we use it in a public health application to produce risk area maps for cryptococcal disease in Colombia. The Genetic Algorithm for Ruleset Production (GARP) was used to create models for Cryptococcus neoformans (C. neoformans) and Cryptococcus gattii (C. gattii), based on environmental sampling and clinical records data recorded since 1987. These maps could be used to focus public health messaging related to cryptococcal disease, and it enables us to characterize the ecological niche for Cryptococcus in Colombia. We found that the ecological niche for C. gattii in Colombia is quite diverse, establishing itself in sub-tropical and temperate ecoregions within the country. This suggests that C. gattii is highly adaptive to different ecological conditions in Colombia and different regions of the world.

Background: Cryptococcus neoformans is an opportunistic fungal pathogen that can cause meningitis in immunocompromised individuals. The objective of this work was to study the relationship between the phenotypes and genotypes of isolates of clinical origin from different cities in Colombia. Methods: Genome classification of 29 clinical isolates of C. neoformans var. grubii was performed using multilocus sequence typing (MLST), and genomic sequencing was used to genotype protein-coding genes. Pathogenicity was assessed in a larval model, and melanin production and capsule size were evaluated in vitro and in vivo. Results: Eleven MLST sequence types (STs) were found, the most frequent being ST69 (n = 9), ST2, ST93, and ST377 (each with n = 4). In the 29 isolates, different levels of pigmentation, capsule size and pathogenicity were observed. Isolates classified as highly pathogenic showed a tendency to exhibit larger increases in capsule size. In the analysis of polymorphisms, 48 non-synonymous variants located in the predicted functional domains of 39 genes were found to be associated with capsule size change, melanin, or pathogenicity. Conclusions: No clear patterns were found in the analysis of the phenotype and genotype of Cryptococcus. However, the data suggest that the increase in capsule size is a key variable for the differentiation of pathogenic isolates, regardless of the method used for its induction.

Cryptococcosis is a potentially fatal opportunistic mycosis that affects the lungs and central nervous system. It has been suggested that certain strains of C. neoformans/C. gattii may have the potential to be more virulent according to the molecular type. This study aims to investigate the association between virulence in the G. mellonella model and genotypic diversity of Colombian clinical and environmental isolates of C. neoformans/C. gattii. A total of 33 clinical and 12 environmental isolates were selected according to their geographical origin and sequence types (STs). Pathogenicity was determined using the G. mellonella model, and the cell and capsular size before and after inoculation was determined. For C. neoformans, virulence in G. mellonella revealed that death occurred on average on day 6 (p < 0.05) and that ST5C, 6C, 25C and 71C were the most virulent. In C. gattii, death occurred at 7.3 days (p < 0.05), and ST47C, 58C, 75A and 106C were the most virulent. Capsular size increased for both species after passage in G. mellonella. In conclusion, the pathogenicity of Cryptococcus strains in the G. mellonella invertebrate model is independent of molecular type or pathogenicity factor, even within the same ST, but it is possible to find variable degrees of pathogenicity.

Background: Candida auris is characterized for having a high genetic variability among species. MALDI-TOF MS library contains spectra from only three strains of C. auris, which makes difficult the identification process and gives low scores at the species level. Our aim was to construct and validate an internal library to improve C. auris identification with Colombian clinical strains. Methods: From 30 clinical strains, 770 mass spectra were obtained for the construction of the database. The validation was performed with 300 strains to compare the identification results in the BDAL and C. auris Colombia libraries. Results: Our library allowed a complete, 100% identification of the evaluated strains and a significant improvement in the scores obtained, showing a better performance compared to the Bruker BDAL library. Conclusions: The strengthening of the database is a great opportunity to improve the scoring and C. auris identification. Library data are available via ProteomeXchange with identifier PXD016387.

Realpe: identificación bioquímica y serotipificación María Elena Realpe: coordinación de las actividades del programa de vigilancia por el laboratorio de la enfermedad diarreica aguda del Grupo de Microbiología Todos los autores participaron en el análisis de resultados y la revisión del manuscrito. Caracterización molecular de aislamientos de Molecular characterization of Shigella sonnei isolates recovered by the Laboratory Surveillance Program for Acute Diarrheal Disease in ColombiaIntroduction: In Colombia, Shigella sonnei is one of the most frequently isolated serotypes (53.4%) in human clinical samples associated with diarrheal acute disease. The identification of DNA restriction patterns by pulsed field gel electrophoresis is the basis for the molecular surveillance of S. sonnei. Objective: To establish the basis for the molecular surveillance of S. sonnei in Colombia using pulsedfield gel electrophoresis. Materials and methods:We studied 102 of 2,048 S. sonnei isolates referred by the National Laboratory Network between 1997 and March, 2013; the selection was made according to the antimicrobial multiresistance profile, the source of samples, and the relation to outbreaks. The genetic profile was determined by pulsed field gel electrophoresis using the restriction enzymes XbaI and BlnI in accordance with the PulseNet International protocol. The electrophoretic patterns were analyzed with the GelCompare II, version 4.0 software. Results:We obtained 42 electrophoretic patterns with a 70% to 100% similarity. The most frequent pattern was COIN08J16X01.0017 with 17.6%, followed by patterns COIN04J16X01.0004 with