Chapter 21
Cultivation of Leptospira interrogans Within Rat Peritoneal
Dialysis Membrane Chambers
Andre Alex Grassmann and Melissa J. Caimano
Abstract
In order to sustain its zoonotic lifecycle, leptospires must adapt to growth within the host milieu. Signals
encountered within the mammal also trigger regulatory programs required by Leptospira for the expression
of virulence-related gene products. The complex transcriptional, antigenic, and physiological changes
leptospires undergo within the mammal are collectively referred to as “host adaptation.” In this chapter,
we describe the procedures for the generation of host-adapted Leptospira spp. by cultivation within dialysis
membrane chambers (DMCs) implanted in rat peritoneal cavities. In this model, Leptospira spp. diluted in
EMJH medium are sequestered within sterile dialysis membrane tubing closed at both ends. The chamber
then is surgically implanted within the peritoneal cavity of a rat and incubated for 7–10 days. During this
period, leptospires are exposed to many, if not all, of the physiological and nutritional cues required for host
adaptation while at the same time protected from clearance by host innate and adaptive immune defenses.
Key words Host adaptation, Dialysis membrane chambers, In vivo model, Bacterial cultivation,
Leptospirosis, Spirochetes
1 Introduction
L. interrogans is maintained in nature within a zoonotic cycle in
which rats are the primary reservoir [1–3]. Infection begins when a
reservoir or an incidental host, including humans, comes into
contact with water or soil contaminated with urine from animal
reservoir. Following acquisition, leptospires switch from a freeliving to a parasitic lifestyle, a complex, multifactorial process
often referred to as “host adaptation.” Once in the bloodstream,
leptospires rapidly disseminate to multiple tissues. The outcome of
these early events differs dramatically depending on whether infection occurs in a reservoir-competent or reservoir-incompetent (i.e.,
incidental) host. In reservoir hosts, leptospires are cleared within
Nobuo Koizumi and Mathieu Picardeau (eds.), Leptospira spp.: Methods and Protocols, Methods in Molecular Biology, vol. 2134,
https://doi.org/10.1007/978-1-0716-0459-5_21, © Springer Science+Business Media, LLC, part of Springer Nature 2020
Electronic supplementary material: The online version of this chapter (https://doi.org/10.1007/978-1-07160459-5_21) contains supplementary material, which is available to authorized users.
229
Cultivation of Leptospira interrogans Within Rat Peritoneal
Dialysis Membrane Chambers
Andre Alex Grassmann and Melissa J. Caimano
Abstract
In order to sustain its zoonotic lifecycle, leptospires must adapt to growth within the host milieu. Signals
encountered within the mammal also trigger regulatory programs required by Leptospira for the expression
of virulence-related gene products. The complex transcriptional, antigenic, and physiological changes
leptospires undergo within the mammal are collectively referred to as “host adaptation.” In this chapter,
we describe the procedures for the generation of host-adapted Leptospira spp. by cultivation within dialysis
membrane chambers (DMCs) implanted in rat peritoneal cavities. In this model, Leptospira spp. diluted in
EMJH medium are sequestered within sterile dialysis membrane tubing closed at both ends. The chamber
then is surgically implanted within the peritoneal cavity of a rat and incubated for 7–10 days. During this
period, leptospires are exposed to many, if not all, of the physiological and nutritional cues required for host
adaptation while at the same time protected from clearance by host innate and adaptive immune defenses.
Key words Host adaptation, Dialysis membrane chambers, In vivo model, Bacterial cultivation,
Leptospirosis, Spirochetes
1 Introduction
L. interrogans is maintained in nature within a zoonotic cycle in
which rats are the primary reservoir [1–3]. Infection begins when a
reservoir or an incidental host, including humans, comes into
contact with water or soil contaminated with urine from animal
reservoir. Following acquisition, leptospires switch from a freeliving to a parasitic lifestyle, a complex, multifactorial process
often referred to as “host adaptation.” Once in the bloodstream,
leptospires rapidly disseminate to multiple tissues. The outcome of
these early events differs dramatically depending on whether infection occurs in a reservoir-competent or reservoir-incompetent (i.e.,
incidental) host. In reservoir hosts, leptospires are cleared within
Nobuo Koizumi and Mathieu Picardeau (eds.), Leptospira spp.: Methods and Protocols, Methods in Molecular Biology, vol. 2134,
https://doi.org/10.1007/978-1-0716-0459-5_21, © Springer Science+Business Media, LLC, part of Springer Nature 2020
Electronic supplementary material: The online version of this chapter (https://doi.org/10.1007/978-1-07160459-5_21) contains supplementary material, which is available to authorized users.
229