@article {dupont_inoculum_1989,
	title = {Inoculum {Size} in {Shigellosis} and {Implications} for {Expected} {Mode} of {Transmission}},
	journal = {The Journal of Infectious Diseases},
	volume = {159},
	number = {6},
	year = {1989},
	pages = {1126{\textendash}1128},
	issn = {0022-1899},
	doi = {10.1093/infdis/159.6.1126},
	url = {https://doi.org/10.1093/infdis/159.6.1126},
	author = {DuPont, Herbert L. and Levine, Myron M. and Hornick, Richard B. and Formal, Samuel B.}
}
@article {kotloff_modified_1995,
	title = {A modified {Shigella} volunteer challenge model in which the inoculum is administered with bicarbonate buffer: clinical experience and implications for {Shigella} infectivity},
	journal = {Vaccine},
	volume = {13},
	number = {16},
	year = {1995},
	month = {jan},
	pages = {1488{\textendash}1494},
	abstract = {{In the absence of a definitive immunologic correlate of protection against shigellosis, promising Shigella vaccine candidates have been selected based on their ability to confer resistance against experimental challenge with wild-type Shigella in healthy adult volunteers. A limitation of this model has been the low and often variable attack rate of illness among controls, necessitating repeated inpatient studies to demonstrate statistically significant results. In this study, the Shigella challenge model was modified by using bicarbonate buffer instead of skimmed milk as the delivery vehicle to enhance survival of the ingested challenge inoculum. To determine the ability of the modified model to detect protective efficacy, 11 veteran volunteers (previously challenged with S. flexneri 2a in bicarbonate buffer) and 12 immunologically naive control subjects were challenged with 1.4 {\texttimes} 103 c.f.u. S. flexneri 2a. Shigellosis occurred in 3 veterans and 11 control subjects (27 vs 92\%},
	keywords = {bacillary dysentery, infectivity, vaccines, volunteers},
	issn = {0264-410X},
	doi = {10.1016/0264-410X(95)00102-7},
	url = {https://www.sciencedirect.com/science/article/pii/0264410X95001027},
	author = {Kotloff, Karen L. and Nataro, James P. and Losonsky, Genevieve A. and Wasserman, Steven S. and Hale, Thomas L. and Taylor, David N. and Sadoff, Jerald C. and Levine, Myron M.}
}
@article {levine_pathogenesis_1973,
	title = {Pathogenesis of {Shigella} dysenteriae 1 ({Shiga}) {Dysentery}},
	journal = {The Journal of Infectious Diseases},
	volume = {127},
	number = {3},
	year = {1973},
	pages = {261{\textendash}270},
	abstract = {The Shiga bacillus is exceptional among enteric pathogens in possessing two potential pathogenetic modes of action, invasiveness and enterotoxin. The role of each was investigated. ,Two fully virulent (invasive toxigenic) and two modified (noninvasive toxigenic and invasive nontoxigenic) Shiga strains were defined in animal and in-vitro models. The virulent strains produced disease in volunteers in doses as low as 101 organisms. Illness was characterized by fever, short-lived diarrhea, and passage of scanty stools of blood and mucus. During illness, the pathogen was isolated from one of 16 samples of small-intestinal contents, and free toxin could not be demonstrated. Concomitantly, large numbers of Shiga organisms were excreted in stool. The major lesions were in the large bowel where clinical colitis was confirmed by proctoscopy and biopsy. Large numbers of a noninvasive toxigenic strain (106-1011 organisms) were well tolerated by 85 of 86 men. One volunteer had dysentery after the organism had reverted to an invasive form. In contrast, an invasive nontoxigenic strain caused shigellosis in monkeys and volunteers. Epithelial penetration is the cardinal virulence property of Shigella dysenteriae 1. The role of Shiga toxin in human disease remains to be defined.},
	issn = {0022-1899},
	doi = {10.1093/infdis/127.3.261},
	url = {https://doi.org/10.1093/infdis/127.3.261},
	author = {Levine, Myron M. and DuPont, Herbert L. and Formal, Samuel B. and Hornick, Richard B. and Takeuchi, Akio and Gangarosa, Eugene J. and Snyder, Merrill J. and Libonati, Joseph P.}
}
