Genetic diversity and geographic distribution of Mycobacterium bovis from cattle in Mexico

Abstract

Se obtuvieron patrones moleculares (espoligotipos) de 878 aislados de Mycobacterium bovis de ganado de diferentes regiones de México entre los años 2009 y 2010. Setenta y dos por ciento (72 %) de los espoligotipos cayeron en nueve grupos y 27 % de los aislados dentro de sólo dos espoligotipos; 149 fueron espoligotipos individuales. Los dos espoligotipos predominantes, arbitrariamente identificados como SP1 y SP2, se distribuyen en la mayor parte del territorio nacional, en especial en la zona centro de México en ganado especializado en producción de leche. A pesar de la amplia distribución geográfica de los espoligotipos de mayor frecuencia, algunos muestran cierta localización, en especial los encontrados en zonas geográficas distantes, como es el caso de Chihuahua y Baja California. Aunque pocos, algunos espoligotipos muestran patrones moleculares distintos a los mostrados por los espoligotipos de mayor frecuencia, sugiriendo fuentes de infección desconocida. La mayoría de los Estados con ganadería predominantemente lechera muestran espoligotipos comunes, lo que sugiere intercambio regional frecuente de ganado. Algunos espoligotipos son comunes en ganado para leche y ganado para carne, lo que sugiere transmisión entre estas dos poblaciones; se desconoce, sin embargo, si los animales de carne infectados provienen de explotaciones extensivas o si son de engordas ubicadas dentro de la explotación lechera. Se propone la tipificación rutinaria de aislados de M. bovis obtenidos en todos los laboratorios de diagnóstico y mejorar la captura de información epidemiológica de los casos, para hacer mejores conclusiones epidemiológicas de la distribución espacial de las cepas de este agente en el territorio nacional.

Phylogenomics analysis of Mycobacterium bovis strains from Mexico: Insight report on its Phylogeography

“…It is the whole genome sequencing analysis combined with genotyping tools, that are being carried out [13,14,27,[39][40][41]. It is true, several studies have shown about the molecular epidemiology but also of the geographical distribution of the ecotypes of the MTBC, mostly using the spoligotypes patterns, or a combination of whole sequencing (WGS) and spoligotypes [8,23,24,29,33,34].…”

“…However, despite the close degree of relationship between the analyzed strains, the National phylogenomic tree (Figures 2A-B; 3A) showed that there is no total grouping trend by zone, since groups are formed with two different states and/or municipalities or with more than two, with the exception of group 1 and 3 indicated in the tree that concentrate strains from the same state/ municipality: Jalisco and Ensenada respectively, while group 2 and 4 are made up of strains from two different states: Coahuila and Querétaro, spadesq_145, spadesq_112 and spadesc_378 for group 2; spadesc_193 and spadesq_131 for group 4, which come from relatively distant states (Figure 3A-B). The presence of strains from the states of Hidalgo (spadesh_269, spadesh_231 and spadesh_232), Querétaro (spadesq_404 and spadesq464) and Jalisco (spadesj_380 and spadesj_381) was also observed, with a greater difference in relation to the rest that are separated from the groups formed (Figure 2A-B), whose particular characteristics can be studied, as well as analyze what has led these strains to move away from the rest within the same geographical area (Figure 3A) [8,23,24,29,33].…”

“…Intense efforts to determine the spread of bTB and the molecular epidemiology of M. bovis transmission status are worldwide [8][9][10][11][12][13]. Most of the reports on bovine tuberculosis (bTB) have focused on genotyping M. bovis strains using Restriction Fragment scale can support the National Program for control, surveillance, and eradication of bTB, avoiding the slaughtering of herds [3,23]. Milián., et al 2012 [23,24] achieved a study of molecular patterns of M. bovis isolates between 2009 and 2010 to characterize outbreaks in infectious disease but is limited in endemic regions with no financial limitations.…”

“…Two Spoligotyping studies have provided data of the most frequent spoligotypes patterns at regional, national and international levels. The transmission and the genomic dynamics [6,11,14,[23][24][25][26]. Moreover, Nava., et al 2015 [27] used VNTR's and spoligotyping to analyze and study M. bovis isolates of 16 states of the Mexican Republican [28][29][30][31].…”

“…Since in Mexico, studies on M. bovis isolates from different states of the Mexican Republic have doing since long time ago toward the use of different genetic tools such as Spoligotpyping, RFLPs, VNTRs, SNPs and WGS (REFS) which have provided knowledge about that strains vary by geography, and have defined strain families based on the presence or absence of spacers in the direct repeat region of the MTBC genome. But spoligotyping diversity is determined at a single locus and not evolutive origin and phylogenetic distances can be reliably infered or calculated [19,[21][22][23]31,32,36]. A deeper insight into the analysis of whole-genome sequences (WGS), may allow to enhance understanding of the global population structure, phylogeography and evolutionary history [13,14,28,[39][40][41].…”