Burkholderia species in human infections in Mexico: Identification of B. cepacia, B. contaminans, B. multivorans, B. vietnamiensis,B. pseudomallei and a new Burkholderia species.

BACKGROUND: Burkholderia sensu stricto is comprised mainly of opportunistic pathogens. This group is widely distributed in the environment but is especially important in clinical settings. In Mexico, few species have been correctly identified among patients, most often B. cepacia is described. METHODOLOGY/PRINCIPAL FINDINGS: In this study, approximately 90 strains identified as B. cepacia with the VITEK2 system were isolated from two medical centers in Mexico City and analyzed by MLSA, BOX-PCR and genome analysis. The initial identification of B. cepacia was confirmed for many strains, but B. contaminans, B. multivorans and B. vietnamiensis were also identified among clinical strains for the first time in hospitals in Mexico. Additionally, the presence of B. pseudomallei was confirmed, and a novel species within the B. cepacia complex was documented. Several strains misidentified as B. cepacia actually belong to the genera Pseudomonas, Stenotrophomonas and Providencia. CONCLUSIONS/SIGNIFICANCE: The presence of different Burkholderia species in Mexico was confirmed. Correct identification of Burkholderia species is important to provide accurate treatment for immunosuppressed patients.

Description of two fatal cases of melioidosis in Mexican children with acute pneumonia: case report.

BACKGROUND: Melioidosis is an infectious disease caused by Burkholderia pseudomallei. In Mexico, the disease is rarely diagnosed in humans and there is no evidence of simultaneous environmental isolation of the pathogen. Here, we describe clinical profiles of fatal cases of melioidosis in two children, in a region without history of that disease. CASE PRESENTATION: About 48 h before onset of symptoms, patients swam in a natural body of water, and thereafter they rapidly developed fatal septicemic illness. Upon necropsy, samples from liver, spleen, lung, cerebrospinal fluid, and bronchial aspirate tissues contained Burkholderia pseudomallei. Environmental samples collected from the locations where the children swam also contained B. pseudomallei. All the clinical and environmental strains showed the same BOX-PCR pattern, suggesting that infection originated from the area where the patients were swimming. CONCLUSIONS: The identification of B. pseudomallei confirmed that melioidosis disease exists in Sonora, Mexico. The presence of B. pseudomallei in the environment may suggest endemicity of the pathogen in the region. This study highlights the importance of strengthening laboratory capacity to prevent and control future melioidosis cases.

Plant growth-promoting bacteria isolated from wild legume nodules and nodules of Phaseolus vulgaris L. trap plants in central and southern Mexico.

Central southern Mexico contains highly diverse legumes. In this study, nodule-associated bacteria (NAB) were isolated from wild legume nodules and from nodules on Phaseolus vulgaris plants used as a plant-trap in soils from the same areas as the wild legumes. The bacteria were identified through the 16S rRNA gene sequence analysis, tested for plant growth-promoting (PGP) activities and the production of antimicrobial compounds, and analyzed for potential nodulation by amplifying the nodC gene. Several genera with PGP activity were isolated from legume nodules, including Achromobacter, Acinetobacter, Bacillus, Brevibacillus, Brevibacterium, Burkholderia, Cupriavidus, Dyella, Ensifer, Enterobacter, Herbaspirillum, Kosakonia, Labrys, Microbacterium, Moraxella, Paraburkholderia, Pseudomonas, Rhizobium, Stenotrophomonas; and Aeromonas, Marinococcus Pseudarthrobacter and Pseudoxanthomonas were found in plant legume nodules for the first time. Pseudomonas was the most common bacteria, and Mimosa pudica was colonized by the largest number of genera (6 different genera). A Burkholderia strain from the Burkholderia cepacia complex and a firmicutes strain harbor the nodC gene, identifying them as potential novel nodulating bacteria and showing that most of the strains isolated in this study were NAB. The most frequent PGP activity identified among the strains isolated from wild legumes was IAA synthesis. Two bacteria, Stenotrophomonas sp. and Rhizobium sp., synthesized more than 250 µg/ml, which is more than the level of synthesis reported in this study for Azospirillum brasilense Sp7 (59.77 µg/ml). Nitrogen fixation and antimicrobial compound production were not common, but the production of siderophores was frequently found among all the strains. This study shows that diverse NAB with PGP activity are very common in the legume nodules from central southern Mexico.

Cupriavidus agavae sp. nov., a species isolated from Agave L. rhizosphere in northeast Mexico.

During the isolation of bacteria from the Agave L. rhizosphere in northeast Mexico, four strains with similar BOX-PCR patterns were collected. The 16S rRNA gene sequences of all four strains were very similar to each other and that of the type strains of Cupriavidus metallidurans CH34T (98.49 % sequence similarity) and Cupriavidus necator N-1T (98.35 %). The genome of strain ASC-9842T was sequenced and compared to those of other Cupriavidus species. ANIb and ANIm values with the most closely related species were lower than 95%, while the in silico DNA-DNA hybridization values were also much lower than 70 %, consistent with the proposal that they represent a novel species. This conclusion was supported by additional phenotypic and chemotaxonomic analyses. Therefore, the name Cupriavidus agavae sp. nov. is proposed with the type strain ASC-9842T (=LMG 26414T=CIP 110327T).

El controvertido complejo Burkholderia cepacia, un grupo de especies promotoras del crecimiento vegetal y patógenas de plantas, animales y humanos / The controversial Burkholderia cepacia complex, a group of plant growth promoting species and plant, animals and human pathogens

El complejo Burkholderia cepacia está formado por 22 especies conocidas como patógenos oportunistas en personas inmunocomprometidas, especialmente en aquellas con fibrosis quística. También se aíslan de infecciones nosocomiales y son difíciles de erradicar debido a su capacidad intrínseca para resistir una gran variedad de antibióticos. En general, estas especies presentan genomas de gran tamaño (hasta 9 Mpb) divididos en 2-5 replicones. Esta característica aporta una gran versatilidad metabólica, que se considera importante para habitar el suelo, el agua, las plantas, incluso los nódulos en leguminosas. Algunas especies del complejo B. cepacia exhiben actividades benéficas, como biorremediación, biocontrol y promoción del crecimiento vegetal. No obstante, debido a su papel en infecciones de humanos, su uso en la agricultura está restringido. El complejo B. cepacia es un tema constante de estudio debido a su impacto en el sector salud y su potencial en la agricultura. En este trabajo se examina la historia del complejo B. cepacia y se revisa la información reciente relacionada con este grupo de bacterias.

The Burkholderia cepacia complex is a group of 22 species, which are known as opportunistic pathogens in immunocompromised people, especially those suffering from cystic fibrosis. It is also found in nosocomial infections and is difficult to eradicate due to intrinsic resistance to several antibiotics. The species have large genomes (up to 9 Mbp), distributed into 2-5 replicons. These features significantly contribute to genome plasticity, which makes them thrive in different environments like soil, water, plants or even producing nodules in legume plants. Some B. cepacia complex species are beneficial in bioremediation, biocontrol and plant-growth promotion. However, because the B. cepacia complex is involved in human infection, its use in agriculture is restricted. B. cepacia complex is being constantly studied due to the health problems that it causes and because of its agricultural potential. In this review, the history of B. cepacia complex and the most recently published information related to this complex are revised.

Misidentification of Burkholderia pseudomallei and Other Burkholderia Species From Pediatric Infections in Mexico.

Burkholderia pseudomallei and Burkholderia cepacia complex are poorly studied in Mexico. The genotypic analysis of 38 strains isolated from children with pneumonia were identified and showed that both Burkholderia groups were present in patients. From our results, it is plausible to suggest that new species are among the analyzed strains.

[The controversial Burkholderia cepacia complex, a group of plant growth promoting species and plant, animals and human pathogens]. / El controvertido complejo Burkholderia cepacia, un grupo de especies promotoras del crecimiento vegetal y patógenas de plantas, animales y humanos.

The Burkholderia cepacia complex is a group of 22 species, which are known as opportunistic pathogens in immunocompromised people, especially those suffering from cystic fibrosis. It is also found in nosocomial infections and is difficult to eradicate due to intrinsic resistance to several antibiotics. The species have large genomes (up to 9 Mbp), distributed into 2-5 replicons. These features significantly contribute to genome plasticity, which makes them thrive in different environments like soil, water, plants or even producing nodules in legume plants. Some B. cepacia complex species are beneficial in bioremediation, biocontrol and plant-growth promotion. However, because the B. cepacia complex is involved in human infection, its use in agriculture is restricted. B. cepacia complex is being constantly studied due to the health problems that it causes and because of its agricultural potential. In this review, the history of B. cepacia complex and the most recently published information related to this complex are revised.