Recently, the pathogen that causes melioidosis, Burkholderia pseudomallei, was found in the Gulf Coast region of Mississippi, United States of America, associated with human cases and as bacteria in ...the soil of affected areas. Therefore, the Centers for Disease Control and Prevention has declared the pathogen as endemic in the continental United States for the first time. This viewpoint discusses some issues that the research, public health communities, and government agencies need to address.
The scientific community is making significant efforts to be inclusive and to promote diversity and equity. The microbial sciences are not the exception, and organizations, such as the American ...Society for Microbiology (ASM), are implementing strategic plans to advance these initiatives. However, one unexplored topic is whether the recruitment of minoritized microbiologists should use tailored programs for the success of trainees and faculty. Some challenges and opportunities are presented for consideration while developing recruitment, retention, and advancement programs in the microbial sciences.
Abstract
The emergence and evolution of pathogenic Escherichia coli strains associated with animal and human infections continues being a topic of active investigation in recent years. Latin America ...has responded to this thread establishing the Latin American Coalition for Escherichia coli Research (LACER), a multidisciplinary group of scientists applying principles of the One Health initiative. LACER is integrating animal, human and environmental health for the mutual benefit of all, while reducing the impact of human disease. Here, I depict the usefulness of this approach by providing three examples from several priority areas in E. coli research and comparing them to the activities performed by LACER, which are enhancing collaborative efforts in biomedical research and providing a translational platform to connect with epidemiological studies and public health policy makers. The manuscript concludes with a brief historical description regarding the establishment of LACER, emphasizing the importance of collaboration between health professionals of different international organizations and not only across one specific country, to effectively combat current and future E. coli infections. The benefits of utilizing ‘One Health’ concepts in the establishment of LACER should encourage other professionals studying zoonotic or environmentally acquired human infections to implement effective international collaborations to combat common problems.
The ‘One Health’ initiative provides a framework to establish international collaborations such as the LACER network.
The Latin American Coalition for Escherichia coli Research (LACER) was created as a network of investigators using One Health approaches trying to understand infections caused by regional E. coli ...isolates and to sound the alarm due to the evolution of strains that are multiresistant to antibiotics (resistome) that also display different virulence profiles (virulome). After the COVID19 pandemic, a major concern by investigators has been the appearance of more virulent and resistant strains. Recently, a paper published in Microbiology Spectrum by Brazilian investigators (Fuga B., et al. Microbiol Spectr 10:e0125621, 2022, https://doi.org/10.1128/spectrum.01256-21) has used a genomic approach to demonstrate that during a period of 45 years, a wide resistome and virulome has converged, resulting in the appearance and persistence of high-risk clones affecting humans, animals and the environment, and its rapid dissemination is becoming an unattended international threat.
Here we exploit the natural properties of a synthetic nanoparticle (NP) scaffold as a subunit vaccine against enterohemorrhagic
(EHEC). Two EHEC-specific immunogenic antigens, namely, LomW and EscC, ...either alone or in combination, were covalently linked on the surface of gold nanoparticles (AuNPs) and used to immunize mice prior to challenge with EHEC O157:H7 strain 86-24. LomW is a putative outer membrane protein encoded in bacteriophage BP-933W, while EscC is a structural type III secretion system protein which forms a ring in the outer membrane. The resulting AuNP preparations, AuNP-LomW and AuNP-EscC, showed that the nanoparticles were able to incorporate the antigens, forming stable formulations that retained robust immunogenicity
after subcutaneous immunization. When administered subcutaneously, AuNP-LomW or AuNP-EscC or a combination containing equivalent amounts of both candidates resulted in higher IgG titers in serum and secretory IgA titers in feces. The serum IgG titers correlated with a significant reduction in EHEC intestinal colonization after 3 days postinoculation. In addition, we showed that serum from antigen-coated AuNP-immunized mice resulted in a reduction of adherence to human intestinal epithelial cells for EHEC, as well as for two other
pathotypes (enteropathogenic
EPEC, encoding EscC, and enteroaggregative
EAEC, encoding LomW). Further, the serum had antigen-specific bactericidal properties, engaging the classical complement pathway. Overall, our results demonstrate the immunogenicity and stability of a novel nanovaccine against EHEC. These results also strengthen the prospect of development of a synthetic nanoparticle vaccine conjugated to
antigens as a promising platform against other enteric pathogens.
Enterohemorrhagic
O157:H7 is a human pathogen and the causative agent of diarrhea and hemorrhagic colitis, which can progress to hemolytic uremic syndrome. These complications represent a serious global public health problem that requires laborious public health interventions and safety control measures to combat recurrent outbreaks worldwide. Today, there are no effective interventions for the control of EHEC infections, and, in fact, the use of antibiotics is counterindicated for EHEC disease. Therefore, a viable alternative for the prevention of human infections is the development of vaccines; however, no such vaccines are approved for human use. In this study, we developed a novel gold nanoparticle platform which acts as a scaffold for the delivery of various antigens, representing a nanovaccine technology which can be applied to several disease models.
A renewed interest in Shiga toxin-producing Escherichia coli (STEC) strains was sparked due to the appearance of an outbreak in 2011, causing 3,816 diarrheal cases and some deaths in Europe. The ...causative strain was classified as enteroaggregative E. coli of serotype O104:H4 that had acquired Shiga toxin genes. The ability of STEC O104:H4 to cause disease relies greatly on the bacteria's capacity to colonize, persist, and produce Shiga toxin. However, not much is known about the colonization factors of this strain. Because long polar fimbriae (lpf) lpf1 and lpf2 operons encode important colonization factors in other STEC isolates and E. coli O104:H4 possesses both loci, we hypothesized that Lpf is required for adhesion and colonization. In this study, isogenic lpfA1 and lpfA2 major fimbrial subunit mutants were constructed. To determine their role in O104:H4's virulence, we assessed their ability to adhere to non-polarized and polarized intestinal epithelial cells. The ΔlpfA1 showed decreased adherence in both cell systems, while the ΔlpfA2 only showed a decrease in adherence to polarized Caco-2 cells. We also tested the O104:H4 mutants' ability to form biofilm and found that the ΔlpfA1 was unable to form a stable biofilm. In an in vivo murine model of intestinal colonization, the ΔlpfA1 had a reduced ability to colonize the cecum and large intestine, consistent with the in vitro data. Further, we tested the lpfA1 mutants' ability to compete against the wild type. We found that in the in vitro and in vivo models, the presence of the wild type O104:H4 facilitates increased adherence of the ΔlpfA1 to levels exceeding that of the wild type. Overall, our data demonstrated that Lpf1 is one of the factors responsible for O104:H4 intestinal adhesion and colonization.
...LACER does not have a complex leadership team; instead, members are frequently consulted and participate in the decision-making process of all activities planned. ...LACER members are devoted to ...improving the quality of education by sharing resources and allowing other groups to have access to equipment, reagents, and protocols that they might not have in their own laboratory.
The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is the etiological agent responsible for the coronavirus disease 2019 (COVID-19). The high rate of mutation of this virus is ...associated with a quick emergence of new viral variants that have been rapidly spreading worldwide. Several mutations have been documented in the receptor-binding domain (RBD) of the viral spike protein that increases the interaction between SARS-CoV-2 and its cellular receptor, the angiotensin-converting enzyme 2 (ACE2). Mutations in the spike can increase the viral spread rate, disease severity, and the ability of the virus to evade either the immune protective responses, monoclonal antibody treatments, or the efficacy of current licensed vaccines. This review aimed to highlight the functional virus classification used by the World Health Organization (WHO), Phylogenetic Assignment of Named Global Outbreak (PANGO), Global Initiative on Sharing All Influenza Data (GISAID), and Nextstrain, an open-source project to harness the scientific and public health potential of pathogen genome data, the chronological emergence of viral variants of concern (VOCs) and variants of interest (VOIs), the major findings related to the rate of spread, and the mutations in the spike protein that are involved in the evasion of the host immune responses elicited by prior SARS-CoV-2 infections and by the protection induced by vaccination.
Colonization of the host epithelia by pathogenic Escherichia coli is influenced by the ability of the bacteria to interact with host surfaces. Because the initial step of an E. coli infection is to ...adhere, invade, and persist within host cells, some strategies used by intestinal and extraintestinal E. coli to infect host cell are presented.
This review highlights recent progress understanding how extraintestinal pathogenic E. coli strains express specific adhesins or invasins that allow colonization of the urinary tract or the meninges, while intestinal E. coli strains are able to colonize different regions of the intestinal tract using other specialized adhesins or invasins. Finally, evaluation of different diets and environmental conditions regulating the colonization of these pathogens is discussed.
Discovery of new interactions between pathogenic E. coli and the host epithelial cells unravels the need for more mechanistic studies that can provide new clues regarding how to combat these infections.
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