Molecular typing of clinical isolates of Cryptococcus neoformans/Cryptococcus gattii species complex from Northeast Mexico

Abstract

Cryptococcosis is caused by members of the Cryptococcus neoformans/Cryptococcus gattii species complex. Based on molecular identification, these two species have been further differentiated into molecular types. The aim of this work was to characterize clinical cryptococcal isolates recovered from six hospitals in Northeast Mexico from 1995 to 2011. One hundred and sixty-six isolates, which were characterized by biochemical tests and in vitro susceptibility to amphotericin B, fluconazole, and voriconazole, and M13 PCR fingerprinting, were included in this study. Utilizing phenotypic tests, 153 isolates (92.16 %) were identified as C. neoformans and 13 (7.83 %) as C. gattii. All isolates were susceptible to all antifungals tested. Employing M13 PCR fingerprinting, eight molecular types were detected. VNI was the most common genotype (124 cases; 74.6 %), followed by VNII (15 cases; 9 %), VNIII (8 cases; 4.8 %), VNIV (6 cases; 3.6 %), VGI (6 cases; 3.6 %), VGII (3 cases; 1.8 %), and VGIII and VGIV (2 cases, 1.2 % each). We confirm the presence of C. gattii in clinical isolates in Northeast Mexico, and a high clonal diversity in the studied strains of C. neoformans/C. gattii species complex.

Ecoepidemiology of Cryptococcus gattii in Developing Countries

“…C. gattii sensu stricto (s.s.) (genotype AFLP4/VGI) is a major aetiologic agent of cryptococcosis among immunocompetent patients from Brazil [ 25 , 26 , 27 ], Colombia [ 29 ], Mexico [ 33 , 34 ], Honduras [ 32 ], and Peru [ 35 ] and has caused pneumonia in a renal transplant patient from Argentina [ 21 ]. This pathogen has also been involved with a fatal infection in Cuba in an imported cheetah from South Africa [ 31 ].…”

“…C. deuterogattii (genotype AFLP6/VGII) has been isolated from clinical samples and has been involved in meningitis, cutaneous diseases, and lung infection in immunocompetent and HIV-positive patients from Brazil [ 25 , 26 , 36 , 37 , 38 ], Colombia [ 29 ], Mexico [ 33 , 34 ], and French Guiana [ 45 ]. From Brazil, it was also reported causing disease in dogs [ 39 , 40 ].…”

“…The species C. bacillisporus (genotype AFLP5/VGIII) has been isolated from clinical samples from Colombian immunocompetent patients [ 29 ], as well as from patients in Mexico [ 33 , 34 ], Cuba [ 88 ], Brazil [ 25 ], Guatemala, Paraguay, and Venezuela [ 48 ]. In the environment, Corymbia ficifolia and Ficus spp.…”

Expansion of the Emerging Fungal Pathogen Cryptococcus bacillisporus Into America: Linking Phylogenetic Origin, Geographical Spread and Population Under Exposure Risk

“…Allele types for each locus and the sequence type (ST), determined by the combination of the seven allele types, were assigned by matching the sequences with those present in the C. gattii MLST database 1 . A phylogenetic tree was reconstructed comparing the ST of the Chilean isolate with 69 different STs from VGIII global isolates previously reported ( Byrnes et al, 2011 ; Lizarazo et al, 2014 ; Singer et al, 2014 ; Springer et al, 2014 ; González et al, 2016 ). Analysis was performed by MEGA software v6.06 2 using maximum likelihood algorithm, Tamura-Nei model, nearest-neighbor-interchange method starting from a neighbor-joining tree for tree inference, and bootstrap analysis on 1000 random repeats as phylogeny test.…”

“…By comparison, C. bacillisporus (VGIII) was identified in patients with HIV/AIDS in the United States, especially in Southern California, with fewer cases in Oregon, Washington, New Mexico, New Jersey, Michigan, and Alaska. Outside the United States, infections were reported in Latin America from Mexico, Colombia, Brazil, Paraguay, Argentina, Venezuela, and Guatemala ( Byrnes et al, 2011 ; Walraven et al, 2011 ; Lockhart et al, 2013 ; Lizarazo et al, 2014 ; Singer et al, 2014 ; Springer et al, 2014 ; González et al, 2016 ; Vélez and Escandón, 2017 ; Berejnoi et al, 2019 ). However, a recent veterinary isolation in a domestic animal was reported for the first time in central Chile, in the locality of Limache, 15 kilometers south of the city of Valparaíso (30°59′S, 71°17′W), extending its southern geographical limit to a geographical area where it has never been recorded before (non-endemic species) ( Vieille et al, 2018 ).…”