First evidence of Klebsiella pneumoniae infection in Aceh cattle: Pathomorphology and antigenic distribution in the lungs

Background and Aim: Klebsiella pneumoniae is an emerging zoonotic and foodborne pathogen worldwide. Hypervirulent K. pneumoniae (hvKp) was reported as the causative agent of bovine mastitis. This is the first study in Indonesia that has been conducted to determine the capsular serotype of K. pneumoniae, pulmonary gross pathology and histopathology, and distribution of hvKp in the lungs of Aceh cattle. Materials and Methods: The presence of K. pneumoniae in Aceh cattle was investigated in two slaughterhouses in Banda Aceh and Aceh Besar, Indonesia. Lung tissues with gross pathological lesions were collected from 15 cattle presenting with depression, dehydration, or cachexia. The confirmation and capsular serotyping of K. pneumoniae isolates were performed using polymerase chain reaction. The tissues were stained with hematoxylin-eosin and immunohistochemistry to observe the histopathological lesions and the distribution of the hvKp antigens. Results: The pneumonic lesions identified in the lungs of Aceh cattle included hyperemia, hemorrhage, consolidation, and atelectasis. K. pneumoniae was isolated in all 15 lung tissues with pathological pneumonic lesions. Two patterns of infection were observed histopathologically. Acute infection was characterized by hyperemia, inflammatory cell infiltration, hemorrhage, bronchiolar epithelium hyperplasia, bronchial and bronchiolar obstruction with purulent exudates, edema, and atelectasis. On the other hand, chronic infection was defined by macrophage infiltration, emphysema, bronchial dilatation, pleural fibrosis, and alveolar wall thickening by interstitial fibrosis. Immunohistochemical staining using monospecific antisera induced by the hvKp isolate confirmed the presence of K. pneumoniae-specific antigens in the acute infection, predominantly in the bronchiolar, vascular, and alveolar areas. In contrast, generally diffuse infiltrates were found in the pleura and interstitial alveolar areas in chronic infection. Conclusion: hvKp can be detected in the lungs of Aceh cattle, representing acute and chronic infections. The distribution of Klebsiella antigens in the lung tissue was consistent with the histopathological findings.

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Significance of a Positive Toxoplasma Immunoglobulin M Test Result in the United States

Journal of Clinical Microbiology ◽

10.1128/jcm.01663-15 ◽

2015 ◽

Vol 53 (11) ◽

pp. 3601-3605 ◽

Cited By ~ 39

Author(s):

Reshika Dhakal ◽

Kiran Gajurel ◽

Christelle Pomares ◽

Jeanne Talucod ◽

Cynthia J. Press ◽

...

Keyword(s):

United States ◽

Chronic Infection ◽

Serological Test ◽

Acute Infection ◽

The United States ◽

Immunoglobulin M ◽

Reference Laboratory ◽

Test Results ◽

Chronic Infections ◽

Content Type

A positiveToxoplasmaimmunoglobulin M (IgM) result is often interpreted as a marker of an acute infection. However, IgM can persist for several years, andToxoplasmacommercial IgM diagnostic test kits can yield a number of false-positive results. For these reasons, a chronicToxoplasmainfection can be erroneously classified as an acute infection, resulting in serious adverse consequences, especially in pregnant women, leading to emotional distress and unnecessary interventions, including termination of pregnancy. Interpretation ofToxoplasmaserology at a reference laboratory can help differentiate a recently acquired infection from a chronic infection. Serological test results for 451 patients with positiveToxoplasmaIgM and IgG test results obtained at nonreference laboratories (NRLs) that were referred to Palo Alto Medical Foundation Toxoplasma Serology Laboratory (PAMF-TSL) to determine whether the patient was acutely or chronically infected were retrospectively reviewed. PAMF-TSL results established that of the 451 patients, 335 (74%) had a chronic infection, 100 (22%) had an acute infection, and 7 (2%) were not infected, and for 9 (2%), results were indeterminate. PositiveToxoplasmaIgM and IgG test results obtained at NRLs cannot accurately distinguish between acute and chronic infections. To do so, testing at reference laboratories is required, as mandated in 1997 in a letter from the Food and Drug Administration (FDA) to clinicians and laboratories in the United States.

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Evolutionary Genomics of Niche-Specific Adaptation to the Cystic Fibrosis Lung in Pseudomonas aeruginosa

Molecular Biology and Evolution ◽

10.1093/molbev/msaa226 ◽

2020 ◽

Author(s):

Jeremy R Dettman ◽

Rees Kassen

Keyword(s):

Cystic Fibrosis ◽

Pseudomonas Aeruginosa ◽

Positive Selection ◽

Chronic Infection ◽

Iron Homeostasis ◽

Acute Infection ◽

Whole Genome Sequence ◽

Chronic Infections ◽

Environmental Strain ◽

Single Strain

Abstract The comparative genomics of the transition of the opportunistic pathogen Pseudomonas aeruginosa from a free-living environmental strain to one that causes chronic infection in the airways of cystic fibrosis (CF) patients remain poorly studied. Chronic infections are thought to originate from colonization by a single strain sampled from a diverse, globally distributed population, followed by adaptive evolution to the novel, stressful conditions of the CF lung. However, we do not know whether certain clades are more likely to form chronic infections than others and we lack a comprehensive view of the suite of genes under positive selection in the CF lung. We analyzed whole-genome sequence data from 1,000 P. aeruginosa strains with diverse ecological provenances including the CF lung. CF isolates were distributed across the phylogeny, indicating little genetic predisposition for any one clade to cause chronic infection. Isolates from the CF niche experienced stronger positive selection on core genes than those derived from environmental or acute infection sources, consistent with recent adaptation to the lung environment. Genes with the greatest differential positive selection in the CF niche include those involved in core cellular processes such as metabolism, energy production, and stress response as well as those linked to patho-adaptive processes such as antibiotic resistance, cell wall and membrane modification, quorum sensing, biofilms, mucoidy, motility, and iron homeostasis. Many genes under CF-specific differential positive selection had regulatory functions, consistent with the idea that regulatory mutations play an important role in rapid adaptation to novel environments.

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Long-Term Relationships: the Complicated Interplay between the Host and the Developmental Stages of Toxoplasma gondii during Acute and Chronic Infections

Microbiology and Molecular Biology Reviews ◽

10.1128/mmbr.00027-15 ◽

2015 ◽

Vol 79 (4) ◽

pp. 387-401 ◽

Cited By ~ 40

Author(s):

Kelly J. Pittman ◽

Laura J. Knoll

Keyword(s):

Toxoplasma Gondii ◽

Chronic Infection ◽

Developmental Stages ◽

Acute Infection ◽

The Body ◽

Sexual Cycle ◽

Parasitic Infections ◽

Chronic Infections ◽

Content Type ◽

Cyst Form

SUMMARYToxoplasma gondiirepresents one of the most common parasitic infections in the world. The asexual cycle can occur within any warm-blooded animal, but the sexual cycle is restricted to the feline intestinal epithelium.T. gondiiis acquired through consumption of tissue cysts in undercooked meat as well as food and water contaminated with oocysts. Once ingested, it differentiates into a rapidly replicating asexual form and disseminates throughout the body during acute infection. After stimulation of the host immune response,T. gondiidifferentiates into a slow-growing, asexual cyst form that is the hallmark of chronic infection. One-third of the human population is chronically infected withT. gondiicysts, which can reactivate and are especially dangerous to individuals with reduced immune surveillance. Serious complications can also occur in healthy individuals if infected with certainT. gondiistrains or if infection is acquired congenitally. No drugs are available to clear the cyst form during the chronic stages of infection. This therapeutic gap is due in part to an incomplete understanding of both host and pathogen responses during the progression ofT. gondiiinfection. While many individual aspects ofT. gondiiinfection are well understood, viewing the interconnections between host and parasite during acute and chronic infection may lead to better approaches for future treatment. The aim of this review is to provide an overview of what is known and unknown about the complex relationship between the host and parasite during the progression ofT. gondiiinfection, with the ultimate goal of bridging these events.

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Viral antigen and extensive division maintain virus-specific CD8 T cells during chronic infection

Journal of Experimental Medicine ◽

10.1084/jem.20061937 ◽

2007 ◽

Vol 204 (4) ◽

pp. 941-949 ◽

Cited By ~ 167

Author(s):

Haina Shin ◽

Shawn D. Blackburn ◽

Joseph N. Blattman ◽

E. John Wherry

Keyword(s):

T Cells ◽

T Cell ◽

Cd8 T Cells ◽

Chronic Infection ◽

Viral Antigen ◽

Acute Infection ◽

Cd8 T Cell ◽

Long Term Memory ◽

Chronic Infections

Efficient maintenance of memory CD8 T cells is central to long-term protective immunity. IL-7– and IL-15–driven homeostatic proliferation is essential for long-term memory CD8 T cell persistence after acute infections. During chronic infections, however, virus-specific CD8 T cells respond poorly to these cytokines. Yet, virus-specific CD8 T cells often persist for long periods of time during chronic infections. We have addressed this apparent paradox by examining the mechanism for maintaining virus-specific CD8 T cells during chronic infection. We find that homeostatic cytokines (e.g., IL-7/15), inflammatory signals, and priming of recent thymic emigrants are not sufficient to maintain virus-specific CD8 T cells over time during chronic infection. Rather, our results demonstrate that viral peptide is required for virus-specific CD8 T cell persistence during chronic infection. Moreover, this viral antigen-dependent maintenance results in a dramatically different type of T cell division than is normally observed during memory T cell homeostasis. Rather than undergoing slow, steady homeostatic turnover during chronic viral infection, CD8 T cells undergo extensive peptide-dependent division, yet cell numbers remain relatively stable. These results indicate that antigen-specific CD8 T cell responses during persisting infection are maintained by a mechanism distinct from that after acute infection.

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Aerosolized bovine lactoferrin reduces neutrophils and pro-inflammatory cytokines in mouse models of Pseudomonas aeruginosa lung infections

Biochemistry and Cell Biology ◽

10.1139/bcb-2016-0050 ◽

2017 ◽

Vol 95 (1) ◽

pp. 41-47 ◽

Cited By ~ 23

Author(s):

Piera Valenti ◽

Alessandra Frioni ◽

Alice Rossi ◽

Serena Ranucci ◽

Ida De Fino ◽

...

Keyword(s):

Pseudomonas Aeruginosa ◽

Mouse Models ◽

Chronic Infection ◽

Bacterial Load ◽

Acute Infection ◽

Lung Infection ◽

Bovine Lactoferrin ◽

Chronic Infections ◽

Airway Infections ◽

Lung Infections

Lactoferrin (Lf), an iron-chelating glycoprotein of innate immunity, produced by exocrine glands and neutrophils in infection/inflammation sites, is one of the most abundant defence molecules in airway secretions. Lf, a pleiotropic molecule, exhibits antibacterial and anti-inflammatory functions. These properties may play a relevant role in airway infections characterized by exaggerated inflammatory response, as in Pseudomonas aeruginosa lung infection in cystic fibrosis (CF) subjects. To verify the Lf role in Pseudomonas aeruginosa lung infection, we evaluated the efficacy of aerosolized bovine Lf (bLf) in mouse models of P. aeruginosa acute and chronic lung infections. C57BL/6NCrl mice were challenged with 106 CFUs of P. aeruginosa PAO1 (acute infection) or MDR-RP73 strain (chronic infection) by intra-tracheal administration. In both acute and chronic infections, aerosolized bLf resulted in nonsignificant reduction of bacterial load but significant decrease of the neutrophil recruitment and pro-inflammatory cytokine levels. Moreover, in chronic infection the bLf-treated mice recovered body weight faster and to a higher extent than the control mice. These findings add new insights into the benefits of bLf as a mediator of general health and its potential therapeutic applications.

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Dampening Host Sensing and Avoiding Recognition inPseudomonas aeruginosaPneumonia

Journal of Biomedicine and Biotechnology ◽

10.1155/2011/852513 ◽

2011 ◽

Vol 2011 ◽

pp. 1-10 ◽

Cited By ~ 14

Author(s):

Cristina Cigana ◽

Nicola Ivan Lorè ◽

Maria Lina Bernardini ◽

Alessandra Bragonzi

Keyword(s):

Chronic Infection ◽

Acute Infection ◽

Immune Surveillance ◽

Opportunistic Pathogen ◽

Bacterial Virulence ◽

Chronic Infections ◽

Pathogenic Variants ◽

Wide Range ◽

Life Threatening ◽

Normal Immune Response

Pseudomonas aeruginosais an opportunistic pathogen and causes a wide range of acute and chronic infections.P. aeruginosainfections are kept in check by an effective immune surveillance in the healthy host, while any imbalance or defect in the normal immune response can manifest in disease. Invasive acute infection in the immunocompromised patients is mediated by potent extracellular and cell bound bacterial virulence factors. Life-threatening chronic infection in cystic fibrosis patients is maintained by pathogenic variants that contribute to evade detection and clearance by the immune system. Here, we reviewed the molecular basis of receptor-mediated recognition ofP. aeruginosaand their role in initiating inflammation and the colonization. In addition, the consequence of theP. aeruginosagenetic adaptation for the antibacterial defence and the maintaining of chronic infection are discussed.

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Complete genome characterization of human noroviruses allows comparison of minor alleles during acute and chronic infections

Access Microbiology ◽

10.1099/acmi.0.000203 ◽

2021 ◽

Author(s):

Daniel Kelly ◽

Khuzwayo C. Jere ◽

Alistair C. Darby ◽

David J. Allen ◽

Miren Iturriza-Gómara

Keyword(s):

Chronic Infection ◽

Massively Parallel Sequencing ◽

Acute Infection ◽

Age Groups ◽

Structural Protein ◽

Chronic Infections ◽

Bioinformatics Pipeline ◽

High Genetic Diversity ◽

Human Noroviruses ◽

Minor Alleles

Human noroviruses (HuNoVs) circulate globally, affect all age groups and place a substantial burden upon health services. High genetic diversity leading to antigenic variation plays a significant role in HuNoV epidemiology, driving periodic global emergence of epidemic variants. Studies have suggested that immunocompromised individuals may be a reservoir for such epidemic variants, but studies investigating the diversity and emergence of HuNoV variants in immunocompetent individuals are underrepresented. To address this, we sequenced the genomes of HuNoVs present in samples collected longitudinally from one immunocompetent (acute infection) and one immunocompromised (chronic infection) patient. A broadly reactive HuNoV capture-based method was used to concentrate the virus present in these specimens prior to massively parallel sequencing to recover near complete viral genomes. Using a novel bioinformatics pipeline, we demonstrated that persistent minor alleles were present in both acute and chronic infections, and that minor allele frequencies represented a larger proportion of the population during chronic infection. In acute infection, minor alleles were more evenly spread across the genome, although present at much lower frequencies, and therefore difficult to discern from error. By contrast, in the chronic infection, more minor alleles were present in the minor structural protein. No non-synonymous minor alleles were detected in the major structural protein over the short sampling period of the HuNoV chronic infection, suggesting where immune pressure is variable or non-existent, epidemic variants could emerge over longer periods of infection by random chance.

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Molecular characterization of KPC-2-producing Klebsiella pneumoniae ST258 isolated from bovine mastitis

Brazilian Journal of Microbiology ◽

10.1007/s42770-021-00445-y ◽

2021 ◽

Author(s):

Jesús Silva-Sanchez ◽

Humberto Barrios-Camacho ◽

Emmanuel Hernández-Rodriguez ◽

Josefina Duran-Bedolla ◽

Alejandro Sanchez-Perez ◽

...

Keyword(s):

Klebsiella Pneumoniae ◽

Molecular Characterization ◽

Bovine Mastitis

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Characterization of Neutralizing Antibody Responses Elicited by Clade A Envelope Immunogens Derived from Early Transmitted Viruses

Journal of Virology ◽

10.1128/jvi.00389-08 ◽

2008 ◽

Vol 82 (12) ◽

pp. 5912-5921 ◽

Cited By ~ 15

Author(s):

Zane Kraft ◽

Katharine Strouss ◽

William F. Sutton ◽

Brad Cleveland ◽

For Yue Tso ◽

...

Keyword(s):

Chronic Infection ◽

Neutralizing Antibodies ◽

Acute Infection ◽

Variable Region ◽

Neutralizing Antibody ◽

Antibody Responses ◽

Virus Envelope ◽

Variable Regions ◽

Clade B ◽

Region Length

ABSTRACT The vast majority of studies with candidate immunogens based on the human immunodeficiency virus envelope (Env) have been conducted with Env proteins derived from clade B viruses isolated during chronic infection. Whether non-clade B Env protein immunogens will elicit antibodies with epitope specificities that are similar to those of antibodies elicited by clade B Envs and whether the antibodies elicited by Envs derived from early transmitted viruses will be similar to those elicited by Envs derived from viruses isolated during chronic infection are currently unknown. Here we performed immunizations with four clade A Envs, cloned directly from the peripheral blood of infected individuals during acute infection, which differed in lengths and extents of glycosylation. The antibody responses elicited by these four Envs were compared to each other and to those elicited by a well-characterized clade B Env immunogen derived from the SF162 virus, which was isolated during chronic infection. Only one clade A Env, the one with the fewer glycosylation sites, elicited homologous neutralizing antibodies (NAbs); these did not target the V1, V2, or V3 regions. In contrast, all four clade A Envs elicited anti-V3 NAbs against “easy-to-neutralize” clade B and clade A isolates, irrespective of the variable region length and extent of glycosylation of the Env used as an immunogen. These anti-V3 NAbs did not access their epitopes on homologous and heterologous clade A, or B, neutralization-resistant viruses. The length and extent of glycosylation of the variable regions on the clade A Env immunogens tested did not affect the breadth of the elicited NAbs. Our data also indicate that the development of cross-reactive NAbs against clade A viruses faces similar hurdles to the development of cross-reactive anti-clade B NAbs.

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