Bistability and bacterial infections.
Bacterial infections occur when the natural host defenses are overwhelmed by invading bacteria. The main component of the host defense is impaired when neutrophil count or function is too low, putting the host at great risk of developing an acute infection. In people with intact immune systems, neut...
| Main Authors: | , , |
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| Format: | Article |
| Language: | English |
| Published: |
Public Library of Science (PLoS)
2010-01-01
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| Series: | PLoS ONE |
| Online Access: | http://europepmc.org/articles/PMC2864736?pdf=render |
| _version_ | 1811203659385536512 |
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| author | Roy Malka Eliezer Shochat Vered Rom-Kedar |
| author_facet | Roy Malka Eliezer Shochat Vered Rom-Kedar |
| author_sort | Roy Malka |
| collection | DOAJ |
| description | Bacterial infections occur when the natural host defenses are overwhelmed by invading bacteria. The main component of the host defense is impaired when neutrophil count or function is too low, putting the host at great risk of developing an acute infection. In people with intact immune systems, neutrophil count increases during bacterial infection. However, there are two important clinical cases in which they remain constant: a) in patients with neutropenic-associated conditions, such as those undergoing chemotherapy at the nadir (the minimum clinically observable neutrophil level); b) in ex vivo examination of the patient's neutrophil bactericidal activity. Here we study bacterial population dynamics under fixed neutrophil levels by mathematical modelling. We show that under reasonable biological assumptions, there are only two possible scenarios: 1) Bacterial behavior is monostable: it always converges to a stable equilibrium of bacterial concentration which only depends, in a gradual manner, on the neutrophil level (and not on the initial bacterial level). We call such a behavior type I dynamics. 2) The bacterial dynamics is bistable for some range of neutrophil levels. We call such a behavior type II dynamics. In the bistable case (type II), one equilibrium corresponds to a healthy state whereas the other corresponds to a fulminant bacterial infection. We demonstrate that published data of in vitro Staphylococcus epidermidis bactericidal experiments are inconsistent with both the type I dynamics and the commonly used linear model and are consistent with type II dynamics. We argue that type II dynamics is a plausible mechanism for the development of a fulminant infection. |
| first_indexed | 2024-04-12T02:59:01Z |
| format | Article |
| id | doaj.art-e90dc04d5bc6444db6e72d6c47521cca |
| institution | Directory Open Access Journal |
| issn | 1932-6203 |
| language | English |
| last_indexed | 2024-04-12T02:59:01Z |
| publishDate | 2010-01-01 |
| publisher | Public Library of Science (PLoS) |
| record_format | Article |
| series | PLoS ONE |
| spelling | doaj.art-e90dc04d5bc6444db6e72d6c47521cca2022-12-22T03:50:44ZengPublic Library of Science (PLoS)PLoS ONE1932-62032010-01-0155e1001010.1371/journal.pone.0010010Bistability and bacterial infections.Roy MalkaEliezer ShochatVered Rom-KedarBacterial infections occur when the natural host defenses are overwhelmed by invading bacteria. The main component of the host defense is impaired when neutrophil count or function is too low, putting the host at great risk of developing an acute infection. In people with intact immune systems, neutrophil count increases during bacterial infection. However, there are two important clinical cases in which they remain constant: a) in patients with neutropenic-associated conditions, such as those undergoing chemotherapy at the nadir (the minimum clinically observable neutrophil level); b) in ex vivo examination of the patient's neutrophil bactericidal activity. Here we study bacterial population dynamics under fixed neutrophil levels by mathematical modelling. We show that under reasonable biological assumptions, there are only two possible scenarios: 1) Bacterial behavior is monostable: it always converges to a stable equilibrium of bacterial concentration which only depends, in a gradual manner, on the neutrophil level (and not on the initial bacterial level). We call such a behavior type I dynamics. 2) The bacterial dynamics is bistable for some range of neutrophil levels. We call such a behavior type II dynamics. In the bistable case (type II), one equilibrium corresponds to a healthy state whereas the other corresponds to a fulminant bacterial infection. We demonstrate that published data of in vitro Staphylococcus epidermidis bactericidal experiments are inconsistent with both the type I dynamics and the commonly used linear model and are consistent with type II dynamics. We argue that type II dynamics is a plausible mechanism for the development of a fulminant infection.http://europepmc.org/articles/PMC2864736?pdf=render |
| spellingShingle | Roy Malka Eliezer Shochat Vered Rom-Kedar Bistability and bacterial infections. PLoS ONE |
| title | Bistability and bacterial infections. |
| title_full | Bistability and bacterial infections. |
| title_fullStr | Bistability and bacterial infections. |
| title_full_unstemmed | Bistability and bacterial infections. |
| title_short | Bistability and bacterial infections. |
| title_sort | bistability and bacterial infections |
| url | http://europepmc.org/articles/PMC2864736?pdf=render |
| work_keys_str_mv | AT roymalka bistabilityandbacterialinfections AT eliezershochat bistabilityandbacterialinfections AT veredromkedar bistabilityandbacterialinfections |