Nippostrongylus brasiliensis

Nippostrongylus brasiliensis	Contents	Rev: 09/04/2025
Rat Hookworm	Classification	Biology and Ecology
	Morphology and Anatomy	Life Cycle
Return to Nippostrongylus Menu	Economic Importance	Ecosystem Functions and Services
	Distribution	Management
Return to Helligmonellidae Menu	Feeding	References
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Classification:

Chromadorea
Chromadoria

Rhabditida
Rhabditina
Infraorder Rhabditomorpha
Heligmosomoidea: Helligmonellidae
Nippostyrongylinae
Nippostrongylus brasiliensis (Travassos, 1914) Lane, 1923

Type species of the genus

Synonyms:

Morphology and Anatomy:

from genus description:

Small nematodes, 2-5 mm long, forming sinistral ventral coils.
Cephalic vesicle present.
Mouth triangular, surrounded by 4 cephalic papillae and amphidial pores.
Cuticle finely striated;
Synlophe well developed with pointed ridges,from just posterior to cephalic vesicle and ending anterior to bursa in male and at vulval level in female. 14 ridges present at mid-body; type A carene supported by hypertrophied left lateral ridge; axis of orientation of ridges passing through ventral-right and dorsal left sides, inclined at 45 degr. from sagittal axis; ridges 2 to 4 well developed; ridges 5 and 6 larger than other ridges in dorsal side of axis of orientation;
Esophagus club-shaped.
Nerve ring slightly posterior to midlevel of esophagus; excretory pore and deirids at midlevel between nerve ring and esophago-intestinal junction.

Nippostrongylus brasiliensis; Gravid female from intestine of mouse
Source: Hoving, 2013; Wikipedia

Females: Monodelphic, prodelphic Vulva posterior, about 120 um from tail tip. Cuticle distended at prevulval level forming small prepuce in some worms. Tail conical with blunt end.

	Males: Bursa asymmetric with larger right lobe partly folding over dorsal lobe. See original description for detail;s of bursal rays. Spicules alate, similar in length, distally united, not strongly twisted, to form pointed end, Gubernaculum small
	Reported median body size for this species (Length mm; width micrometers; weight micrograms) - Click:

Distribution:

A gastrotinetstinal parasite of rodents, primarily rats.

Nippostrongylus. brasiliensis is well-adapted to parasitizing rats and can produce eggs for long periods in the host tissues. It is less well edapted as a parasite of mice in which the immune response prevents egg production by day 8 and adults are expelled by day 10 (Locksley and Robertson, 2007). However, inbred and mutant mouse strains are useful for understanding the biology of the immune response

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Biology and Ecology:

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Life Cycle:

A widely studied parasite due to its simple lifecycle and its utility as a model system.

The direct lifecycle with five stages is similar to those of the human hookworms Necator americanus and Ancylostoma duodenale, Eggs deposited in fecal material into soil hatch to L1 juveniles and molt twice to become the infective L3 stage.

Life cycle of Nippostrongylus brasiliensis in rat. Illustrrated by Angela Debenetti in Galan-Puchades et al., (2025)

The infection takes place in two phases:

Phase 1: The L3 stage penetrates through intact skin in as little as 4 hours. Inside the host, the L3 juveniles invade the venous circulation system and are carried into the lungs, where they become trapped in the capillaries. When they into the L4 stage, they rupture the capillaries and are released into the alveoli, where they are coughed up through the trachea and swallowed.

Phase 2: When they reach the small intestine, 3-4 days after the initial infection, the nematodes undergo the final molt into the adult stage. Egg laying commences by the 6th day after infection (Locksley and Robertson, 2007). Eggs are defecated by the host; egg hatch and infection of new hosts occurs

Laboratory mice infected with N. brasiliensis can develop emphysema during Phase 1 of the infection. Damage includes dilation of distal airspaces due to the loss of alveolar septa during the initial infection of the lungs;. the infection can result in deterioration of the lung, destruction to the alveoli, and long-term airway hyperresponsiveness. The damage is consistent with emphysema and chronic obstructive pulmonary disorder (COPD). This infection can lead to chronic low level hemorrhaging of the lung and loss of body mass of the host (Marsland et al., 2008)..

Ecophysiological Parameters:

For Ecophysiological Parameters for this species, click	If species level data are not available, click for genus level parameters

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Ecosystem Functions and Services:

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Management:

Levamisole is an effective anthelminthic for treatment of infected rats.

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References:

Durette-Desset, M.C. 1970. Le genre Nippostrongylus Lane, 1923 (Nematoda: Heligmosomatidae). Annales de Parasitologie Humaine et Comparee, 45:815-821.

Galan-Puchades, M.T., Gomez-Samblas, M., Trelis, M., Osuna, A., Bueno-Marï¿½, R., Saez-Durï¿½n, S., Conn, D.B. and Fuentes, M.V., 2025. New data on the life cycle of Nippostrongylus brasiliensis (Travassos, 1914) (Nematoda: Heligmosomidae): development of eggs and larval stages in the intestine of naturally infected Rattus norvegicus (Berkenhout, 1769). Parasitology Research, 124(2):1-10.

Hoving, J.C. 2013. PLoS Neglected Tropical Diseases Issue Image Vol. 7(8) August 2013

Locksley, R.M., and Robertson, M. 2007. Immunity: The Immune Response in Infectious and Inflammatory Disease. By Anthony L. DeFranco. N.p.: New Science, 274-275.

Marsland, B.J., Kurrer, M., Reissmann, R., Harris,N.L. and Kopf, M. 2008. Nippostrongylus brasiliensis infection leads to the development of emphysema associated with the induction of alternatively activated macrophages. European Journal of Immunology 38:479-488.

Shaker, S.K.,Dyer, A. and Storey, D.M. 1992. Treatment of Nippostrongylus brasiliensis in normal and SPF rats using tetramisole loaded with zeolite. Journal of Helminthology 66:288-292.

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