scholarly journals Levels of pathogen virulence and host resistance both shape the antibody response to an emerging bacterial disease

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Daisy E. Gates ◽  
Molly Staley ◽  
Luc Tardy ◽  
Mathieu Giraudeau ◽  
Geoffrey E. Hill ◽  
...  
Keyword(s):  
Host Resistance ◽  
Serum Antibody ◽  
Bacterial Disease ◽  
Free Living ◽  
House Finches ◽  
Pathogen Virulence ◽  
Pathogen Load ◽  
Virulent Strains ◽  
Susceptible Populations ◽  
Antibody Levels

AbstractQuantifying variation in the ability to fight infection among free-living hosts is challenging and often constrained to one or a few measures of immune activity. While such measures are typically taken to reflect host resistance, they can also be shaped by pathogen effects, for example, if more virulent strains trigger more robust immune responses. Here, we test the extent to which pathogen-specific antibody levels, a commonly used measure of immunocompetence, reflect variation in host resistance versus pathogen virulence, and whether these antibodies effectively clear infection. House finches (Haemorhous mexicanus) from resistant and susceptible populations were inoculated with > 50 isolates of their novel Mycoplasma gallisepticum pathogen collected over a 20-year period during which virulence increased. Serum antibody levels were higher in finches from resistant populations and increased with year of pathogen sampling. Higher antibody levels, however, did not subsequently give rise to greater reductions in pathogen load. Our results show that antibody responses can be shaped by levels of host resistance and pathogen virulence, and do not necessarily signal immune clearance ability. While the generality of this novel finding remains unclear, particularly outside of mycoplasmas, it cautions against using antibody levels as implicit proxies for immunocompetence and/or host resistance.

scholarly journals Contrasting evolution of virulence and replication rate in an emerging bacterial pathogen

2019 ◽  
Vol 116 (34) ◽  
pp. 16927-16932 ◽  
Author(s):  
Luc Tardy ◽  
Mathieu Giraudeau ◽  
Geoffrey E. Hill ◽  
Kevin J. McGraw ◽  
Camille Bonneaud
Keyword(s):  
Host Resistance ◽  
Bacterial Pathogen ◽  
Mediating Effect ◽  
Replication Rate ◽  
House Finches ◽  
Pathogen Virulence ◽  
Virulence Evolution ◽  
Evolution Of Virulence ◽  
Immune Manipulation ◽  
The Relationship

Host resistance through immune clearance is predicted to favor pathogens that are able to transmit faster and are hence more virulent. Increasing pathogen virulence is, in turn, typically assumed to be mediated by increasing replication rates. However, experiments designed to test how pathogen virulence and replication rates evolve in response to increasing host resistance, as well as the relationship between the two, are rare and lacking for naturally evolving host–pathogen interactions. We inoculated 55 isolates of Mycoplasma gallisepticum, collected over 20 y from outbreak, into house finches (Haemorhous mexicanus) from disease-unexposed populations, which have not evolved protective immunity to M. gallisepticum. We show using 3 different metrics of virulence (body mass loss, symptom severity, and putative mortality rate) that virulence has increased linearly over >150,000 bacterial generations since outbreak (1994 to 2015). By contrast, while replication rates increased from outbreak to the initial spread of resistance (1994 to 2004), no further increases have occurred subsequently (2007 to 2015). Finally, as a consequence, we found that any potential mediating effect of replication rate on virulence evolution was restricted to the period when host resistance was initially increasing in the population. Taken together, our results show that pathogen virulence and replication rates can evolve independently, particularly after the initial spread of host resistance. We hypothesize that the evolution of pathogen virulence can be driven primarily by processes such as immune manipulation after resistance spreads in host populations.

scholarly journals Host exposure history modulates the within-host advantage of virulence in a songbird-bacterium system

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Ariel E. Leon ◽  
Arietta E. Fleming-Davies ◽  
Dana M. Hawley
Keyword(s):  
Bacterial Pathogen ◽  
Host Immunity ◽  
Prior Exposure ◽  
Immune Memory ◽  
House Finches ◽  
Pathogen Virulence ◽  
Host Protection ◽  
Pathogen Load ◽  
High Virulence ◽  
Pathogen Exposure

AbstractThe host immune response can exert strong selective pressure on pathogen virulence, particularly when host protection against reinfection is incomplete. Since emerging in house finch populations, the bacterial pathogen Mycoplasma gallisepticum (MG) has been increasing in virulence. Repeated exposure to low-doses of MG, a proxy for what birds likely experience while foraging, provides significant but incomplete protection against reinfection. Here we sought to determine if the within-host, pathogen load advantage of high virulence is mediated by the degree of prior pathogen exposure, and thus the extent of immune memory. We created variation in host immunity by experimentally inoculating wild-caught, MG-naïve house finches with varying doses and number of exposures of a single pathogen strain of intermediate virulence. Following recovery from priming exposures, individuals were challenged with one of three MG strains of distinct virulence. We found that the quantitative pathogen load advantage of high virulence was strongly mediated by the degree of prior exposure. The greatest within-host load advantage of virulence was seen in hosts given low-dose priming exposures, akin to what many house finches likely experience while foraging. Our results show that incomplete host immunity produced by low-level prior exposure can create a within-host environment that favors more virulent pathogens.

Antibody response of carp, Cyprinus carpio to the cestode, Bothriocephalus acheilognathi

Parasitology ◽  
1999 ◽  
Vol 118 (6) ◽  
pp. 635-639 ◽  
Author(s):  
P. NIE ◽  
D. HOOLE
Keyword(s):  
Antibody Response ◽  
Cyprinus Carpio ◽  
Serum Antibody ◽  
Infected Fish ◽  
Immune Protection ◽  
Carp Cyprinus Carpio ◽  
Bothriocephalus Acheilognathi ◽  
Protection Against Infection ◽  
Antibody Levels ◽  
Antibody Secreting Cells

The humoral antibody response and the number of pronephric antibody-secreting cells were examined in naturally Bothriocephalus acheilognathi-infected carp. Cyprinus carpio, and in those injected intraperitoneally with an extract of the cestode. In the extract-injected fish, specific antibody was detected 3 weeks after a second injection given 2 weeks after the primary injection, and antibody levels persisted for more than 200 days. A third injection also enhanced the antibody level in the extract-injected carp. The numbers of antibody-secreting cells were significantly higher in carp injected 3 times with the extract than in the control. In naturally-infected fish, the serum antibody levels and the number of pronephric antibody-secreting cells were higher in infected fish than in uninfected individuals although this difference was not statistically significant. The relevance of these results to immune protection against infection is discussed.

scholarly journals Low Immunogenicity of Intravesical Phage Therapy for Urogenitary Tract Infections

Antibiotics ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 627
Author(s):  
Sławomir Letkiewicz ◽  
Marzanna Łusiak-Szelachowska ◽  
Ryszard Międzybrodzki ◽  
Maciej Żaczek ◽  
Beata Weber-Dąbrowska ◽  
...  
Keyword(s):  
Clinical Trial ◽  
Bacterial Infections ◽  
Phage Therapy ◽  
Serum Antibody ◽  
Multidrug Resistant ◽  
Antibody Responses ◽  
Urogenital Infections ◽  
Reliable Model ◽  
Tract Infections ◽  
Antibody Levels

Patients with chronic urinary and urogenital multidrug resistant bacterial infections received phage therapy (PT) using intravesical or intravesical and intravaginal phage administration. A single course of PT did not induce significant serum antibody responses against administered phage. Whilst the second cycle of PT caused a significant increase in antibody levels, they nevertheless remained quite low. These data combined with good therapy results achieved in some patients suggest that this mode of PT may be an efficient means of therapy for urogenital infections and a reliable model for a clinical trial of PT.

Specific serum antibody levels and periodontal destruction.

1984 ◽  
Vol 19 (6) ◽  
pp. 614-617 ◽  
Author(s):  
H. K. Hrodek ◽  
R. Gmur ◽  
U. Saxlr ◽  
B. Guggenheim
Keyword(s):  
Serum Antibody ◽  
Specific Serum ◽  
Periodontal Destruction ◽  
Antibody Levels

The Influence of Tonsillectomy on Total Serum Antibody Levels

2014 ◽  
Vol 80 (5) ◽  
pp. 377-379 ◽  
Author(s):  
G. Pidelaserra Martí ◽  
K. G. Isdahl Mohn ◽  
R. J. Cox ◽  
K. A. Brokstad
Keyword(s):  
Serum Antibody ◽  
Total Serum ◽  
Antibody Levels

scholarly journals Stability over Time of Serum Antibody Levels to Human Papillomavirus Type 16

1998 ◽  
Vol 177 (6) ◽  
pp. 1710-1714 ◽  
Author(s):  
Veronika af Geijersstam ◽  
Mari Kibur ◽  
Zhaohui Wang ◽  
Pentti Koskela ◽  
Eero Pukka la ◽  
...  
Keyword(s):  
Human Papillomavirus ◽  
Serum Antibody ◽  
Human Papillomavirus Type 16 ◽  
Antibody Levels ◽  
Over Time

Study of Antibody Levels in Children with Purulent Otitis Media

1980 ◽  
Vol 89 (3_suppl) ◽  
pp. 117-120 ◽  
Author(s):  
P. Branefors ◽  
T. Dahlberg ◽  
O. Nylén
Keyword(s):  
Otitis Media ◽  
Serum Antibody ◽  
Acute Otitis Media ◽  
High Serum ◽  
Haemophilus Influenzae Type ◽  
Enzyme Linked Immunosorbent Assay ◽  
Polysaccharide Antigens ◽  
Antibody Titers ◽  
Iga Antibody ◽  
Antibody Levels

A series of episodes of acute otitis media were studied with reference to the bacterial findings in the nasopharynx and the specific antibody response in a group of children nine months to ten years of age, with previous frequent episodes of acute otitis media, Serum IgG, IgM and IgA antibody levels against five polysaccharide antigens, namely Haemophilus influenzae type b and Streptococcus pneumoniae types 3, 6, 19 and 23, were studied by means of an enzyme-linked immunosorbent assay. The selection of polysaccharide antigens was based on isolation frequency. The sera to be tested were tenfold serially diluted. An extinction of 0.2 over the base was taken as the end-point titer and expressed as in-log10. The results showed that most children including those under three years of age showed increasing homologous antibody titers at an infection, or had already initially very high antibody titers, especially of the IgG class. The titers reached levels of 104 to 105. In some cases, however, it could be shown that high serum antibody titers did not give protection against a new infection with the same serological type of bacteria. It was also demonstrated that most children, regardless of age, had IgG and IgM titers against the heterologous antigens. In some cases the levels were quite high (103 to 104). However, the IgA antibody levels were lower and in a considerable number of samples antibodies were not even detectable.

scholarly journals Longitudinal analysis of virus load, serum antibody levels and virus neutralizing activity in vitro in cases with less severe COVID-19

2020 ◽  
Author(s):  
Bertram Flehmig ◽  
Michael Schindler ◽  
Natalia Ruetalo ◽  
Ramona Businger ◽  
Manfred Bayer ◽  
...  
Keyword(s):  
Serum Antibody ◽  
Disease Onset ◽  
Igg Antibodies ◽  
Virus Load ◽  
Neutralizing Activity ◽  
N Protein ◽  
Life Threatening ◽  
Antibody Levels ◽  
The Relationship

Background: Patients infected with SARS-CoV-2 exhibit a highly variable clinical course, varying from barely discernible signs of disease, to moderate flu-like symptoms and, occasionally, with life-threatening pneumonia and/or cytokine storm. The relationship between the nasopharyngeal virus load, IgA and IgG antibodies to both the S1-RBD-protein and the N-protein as well the neutralizing activity (NAbs) against SARS-CoV-2 in the blood of moderately afflicted COVID-19 patients has not been investigated longitudinally so far. Methods: Several new serological methods to examine these parameters were developed and validated for the longitudinal investigation in three patients of a family which underwent a mild course of COVID-19. Findings: We observed that the virus load had almost completely disappeared after about four weeks, whereas serum antibodies showed a contrasting course. IgA levels to S1-RBD-protein and, to a lesser extent, to the N-protein, peaked about three weeks after clinical disease onset but declined soon thereafter. IgG levels rose continuously, reaching a plateau approximately six weeks after disease onset. NAbs in serum reached a peak about four weeks after disease onset but dropped to a lower level about six weeks later. Interpretation: Our data establishes associations of virus neutralization and a serological immune response foremost against Sars-CoV-2 S1-RDB-protein in a longitudinal manner.

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