Publications by authors named "Liliana Losada"

The annotated genome of , a recently discovered drug-resistant pathogen, was determined by employing the Oxford Nanopore MinION platform and the Funannotate pipeline. The genome size and the number of protein-coding genes are notably larger than those of the most common etiological agent of aspergillosis, .

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  • The lab studied a specific gene encoding an arginine methyltransferase that influences aflatoxin production and developmental processes in a fungus responsible for contaminating various oil seed crops.
  • RNA sequencing revealed that this gene affects over 2000 other genes, including many related to stress responses and a potential new compound synthesis.
  • Interestingly, while the gene was not crucial for the fungus's ability to cause disease in animals, its increased expression led to higher mortality rates compared to the standard strain.
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Burkholderia pseudomallei, the aetiological agent of melioidosis, is an inhabitant of soil and water in many tropical and subtropical regions worldwide. It possesses six distinct type VI secretion systems (T6SS-1 to T6SS-6), but little is known about most of them, as they are poorly expressed in laboratory culture media. A genetic screen was devised to locate a putative repressor of the T6SS-2 gene cluster and a MarR family transcriptional regulator, termed TctR, was identified.

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Aspergillus flavus is a saprophytic fungus that infects corn, peanuts, tree nuts and other agriculturally important crops. Once the crop is infected the fungus has the potential to secrete one or more mycotoxins, the most carcinogenic of which is aflatoxin. Aflatoxin contaminated crops are deemed unfit for human or animal consumption, which results in both food and economic losses.

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Pneumococcal pneumonia has decreased significantly since the implementation of the pneumococcal conjugate vaccine (PCV), nevertheless, in many developing countries pneumonia mortality in infants remains high. We have undertaken a study of the nasopharyngeal (NP) microbiome during the first year of life in infants from The Philippines and South Africa. The study entailed the determination of the sp.

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Background: The genus Bordetella consists of nine species that include important respiratory pathogens such as the 'classical' species B. bronchiseptica, B. pertussis and B.

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Bordetella hinzii is known to cause respiratory disease in poultry and has been associated with a variety of infections in immunocompromised humans. In addition, there are several reports of B. hinzii infections in laboratory-raised mice.

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We used ribonucleic acid sequencing to profile transcription within biliary fluid from a patient with cholangitis; samples were collected before and after treatment with fluconazole and drainage. transcriptomes at the infection site distinguished treated from untreated cholangitis. After treatment, 1131 genes were differentially expressed in biliary fluid.

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Urologic and kidney problems are common in women across their life span and affect their daily life, including physical activity, sexual relations, social life, and future health. Urological health in women is still understudied and the underlying mechanisms of female urological dysfunctions are not fully understood. The Society for Women's Health Research (SWHR) recognized the need to have a roundtable discussion where researchers and clinicians would define the current state of knowledge, gaps, and recommendations for future research directions to transform women's urological health.

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Article Synopsis
  • Researchers sequenced genomes of various Escherichia coli strains, including types that produce Shiga toxin, and found 39 plasmids containing virulence genes.
  • Some plasmids were linked to antibiotic resistance against multiple drug classes and heavy metals, with two plasmids showing resistance to six different types of antibiotics.
  • The study suggests that plasmids carrying these resistance and virulence traits can circulate widely among different E. coli serotypes, regardless of their origins.
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Bacterial persistence due to antibiotic tolerance is a critical aspect of antibiotic treatment failure, disease latency, and chronic or reemergent infections. The levels of persisters is especially notable for the opportunistic Gram-negative pathogens from the Burkholderia and Pseudomonas genera. We examined the rate of drug tolerant persisters in Burkholderia pseudomallei, Burkholderia thailandensis, Burkholderia cepacia complex organisms, and Pseudomonas aeruginosa at mid-log growth in LB broth culture.

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Invasive aspergillosis (IA) due to Aspergillus fumigatus is a major cause of mortality in immunocompromised patients. The discovery of highly fertile strains of A. fumigatus opened the possibility to merge classical and contemporary genetics to address key questions about this pathogen.

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Article Synopsis
  • Bordetella bronchiseptica can infect both mammals and birds.
  • The study presents genome sequences from 53 different isolates of the bacteria found in various land and water animals.
  • This research will help scientists learn more about how the bacteria evolve, adapt to different hosts, and its ability to cause disease.
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Aflatoxin contamination of food and livestock feed results in significant annual crop losses internationally. Aspergillus flavus is the major fungus responsible for this loss. Additionally, A.

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Bordetella hinzii is a Gram-negative bacterium known to infect poultry, humans, rabbits, and rodents. It is an opportunistic pathogen in immunocompromised humans, and some strains cause mild to moderate respiratory disease in turkeys. Little is known as to the degree of genetic diversity within the species or the genetic basis for virulence.

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The DNA sequence of the O-antigen gene clusters of Escherichia coli serogroups O62, O68, O131, O140, O142, and O163 was determined, and primers based on the wzx (O-antigen flippase) and/or wzy (O-antigen polymerase) genes within the O-antigen gene clusters were designed and used in PCR assays to identify each serogroup. Specificity was tested with E. coli reference strains, field isolates belonging to the target serogroups, and non-E.

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Receipt of broad-spectrum antibiotics enhances Candida albicans colonization of the GI tract, a risk factor for haematogenously-disseminated candidiasis. To understand how antibiotics influence C. albicans colonization, we treated mice orally with vancomycin or a combination of penicillin, streptomycin, and gentamicin (PSG) and then inoculated them with C.

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Background: Microbiome studies incorporate next-generation sequencing to obtain profiles of microbial communities. Data generated from these experiments are high-dimensional with a rich correlation structure but modest sample sizes. A statistical model that utilizes these microbiome profiles to explain a clinical or biological endpoint needs to tackle high-dimensionality resulting from the very large space of variable configurations.

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Iron plays a critical role in survival and virulence of the opportunistic pathogen Aspergillus fumigatus. Two transcription factors, the GATA-factor SreA and the bZip-factor HapX oppositely monitor iron homeostasis with HapX activating iron acquisition pathways (e.g.

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The soil fungus Rhizoctonia solani is a pathogen of agricultural crops. Here, we report on the 51,705,945 bp draft consensus genome sequence of R. solani strain Rhs1AP.

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We utilized RNAseq analysis of the Aspergillus fumigatus response to early hypoxic condition exposure. The results show that more than 89% of the A. fumigatus genome is expressed under normoxic and hypoxic conditions.

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Among the species that cause blue mold, isolates of Penicillium expansum are the most prevalent and virulent species, causing more than 50 percent of postharvest decay. We report the draft genome sequence of P. expansum R19 in order to identify fungal virulence factors and to understand the mechanism of infection.

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Article Synopsis
  • An emerging pathogen, Bordetella holmesii, is being linked to more cases resembling pertussis, or whooping cough.
  • Analysis of the genomes from 9 clinical isolates reveals that they are genetically similar and lack the virulence factors typically seen in Bordetella pertussis.
  • The genomic information can be used to develop new markers for identifying B. holmesii.
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Background: The unfolded protein response (UPR) is a network of intracellular signaling pathways that supports the ability of the secretory pathway to maintain a balance between the load of proteins entering the endoplasmic reticulum (ER) and the protein folding capacity of the ER lumen. Current evidence indicates that several pathogenic fungi rely heavily on this pathway for virulence, but there is limited understanding of the mechanisms involved. The best known functional output of the UPR is transcriptional upregulation of mRNAs involved in ER homeostasis.

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