Optimal Proliferation and Differentiation of Chlamydia Trachomatis

Stochastic Modeling of In Vitro Bactericidal Potency

We provide a Galton-Watson model for the growth of a bacterial population in the presence of antibiotics. We assume that bacterial cells either die or duplicate, and the corresponding probabilities depend on the concentration of the antibiotic. Assuming that the mean offspring number is given by [Formula: see text] for some [Formula: see text], where c stands for the antibiotic concentration we obtain weakly consistent, asymptotically normal estimator both for [Formula: see text] and for the minimal inhibitory concentration, a relevant parameter in pharmacology. We apply our method to real data, where Chlamydia trachomatis bacterium was treated by azithromycin and ciprofloxacin. For the measurements of Chlamydia growth quantitative polymerase chain reaction technique was used. The 2-parameter model fits remarkably well to the biological data.

Stochastic Chlamydia Dynamics and Optimal Spread

Chlamydia trachomatis is an important bacterial pathogen that has an unusual developmental switch from a dividing form (reticulate body or RB) to an infectious form (elementary body or EB). RBs replicate by binary fission within an infected host cell, but there is a delay before RBs convert into EBs for spread to a new host cell. We developed stochastic optimal control models of the Chlamydia developmental cycle to examine factors that control the number of EBs produced. These factors included the probability and timing of conversion, and the duration of the developmental cycle before the host cell lyses. Our mathematical analysis shows that the observed delay in RB-to-EB conversion is important for maximizing EB production by the end of the intracellular infection.