A research status of Libyostrongylus genus in ostriches (Struthio camelus): a review

Ushbu tezisda Libyostrongylus avlodiga mansub 3 ta turdagi nematoda haqida olimlar tomonidan o‘rganilganlik holati bayon etilgan.

FUNDAMENTAL VA AMALIY MIKROBIOLOGIYANING BUGUNGI HOLATI VA RIVOJLANISH ISTIQBOLLARI: YOSH OLIMLAR NIGOHI Respublika ilmiy-amaliy anjumani · Toshkent, 2026-yil 30-oktabr

VI YOSH OLIMLAR TADQIQOTLARI VA INNOVATSION ISHLANMALAR DOI 10.66073/ReFocus-Conf/3010135

A RESEARCH STATUS OF LIBYOSTRONGYLUS GENUS IN OSTRICHES (STRUTHIO CAMELUS): A REVIEW Ibragimova Sohiba Uktam qizi1*, Gandjaeva Lola2 Khorezm Mamun Academy Kimyo International University in Tashkent Abstract: This paper outlines the current state of research regarding three nematode species belonging to the genus Libyostrongylus. Keywords: Libyostrongylus douglassii, Libyostrongylus dentatus, Libyostrongylus magnus, distribution. Annotatsiya: Ushbu tezisda Libyostrongylus avlodiga mansub 3 ta turdagi nematoda haqida olimlar tomonidan o‘rganilganlik holati bayon etilgan. Kalit so‘zlar: Libyostrongylus douglassii, Libyostrongylus dentatus, Libyostrongylus magnus, tarqalish. Аннотация: В данной статье представлен обзор современного состояния исследований трех видов нематод, относящихся к роду Libyostrongylus. Ключевые слова: Libyostrongylus douglassii, Libyostrongylus dentatus, Libyostrongylus magnus, распространение. According to the data given by Ederli N. B. some ostrich-specific nematodes were determined for the first time by Arthur Douglass who gathered small nematodes from a proventriculus of an ostrich in South Africa in 1880 and these nematodes were sent to Cobbold who determined the worms and called this new species as Strongylus douglassii in the honor of their collector and announced this in the paper published under the name “New entozoon from the ostriches” in 1882. Later, Lane laid the foundation of the Libyostrongylus genus for some African Trichostrongylidae, where Libyostrongylus douglassii is the type species from ostriches, and Libyostrongylus hebrenicutus (Lane, 1923), is the type species for gorillas [3]. Gilbert described a new species Libyostrongylus magnus, being defined solely in ostriches in the African continent, without recent reports in the world. Ortlepp established the genus Paralibyostrongylus; being Paralibyostrongylus vondwei Ortlepp, 1939, the type species and Paralibyostrongylus hebrenicutus, and Paralibyostrongylus nigeriae Baylis, 1928 included in this new genus. Hoberg E.P. et al. reported a third species, called Libyostrongylus dentatus (Hoberg, Lloyd, and Omar, 1995), because of the existence of prominent esophageal teeth [3,4]. The original geographical distribution of Libyostrongylus sp. is Africa; however, Libyostrongylus douglassii and Libyostrongylus dentatus have been documented from several non-African countries, thus having been introduced with ostriches imported for farming [1,2,3]. In ostriches, the trichostrongylid nematodes Libyostrongylus douglassii (most common), Libyostrongylus dentatus, and Libyostrongylus magnus are found in the openings of the deep proventricular glands and under the koilin layer of the proventriculus and the gizzard [3]. All of these can infect the proventriculus of ostriches [3]. The most usual species is Libyostrongylus douglassii, which has been recorded by Reinecke (1983) [3], Fockema et al. (1985) [3], Pintori et al. (2000) in Italy; Paliy A.P. et al. (2020) in Ukraine [3]. Libyostrongylus dentatus was recorded by Hoberg E.P. et al. (1995) in North America [4], Bonadimon et al. (2006) in Brazil [3], Ederli, N.B. and Oliveira, F.C.R. (2015) in

FOR CITATION Ibragimova S., Gandjaeva L. A research status of Libyostrongylus genus in ostriches (Struthio camelus): a review // Proceedings of the Republican Scientific and Practical Conference “Status and Development Prospects of Fundamental and Applied Microbiology: The Viewpoint of Young Scientists”. – Tashkent, 2026. – P. 478–480. DOI: https://doi.org/10.66073/ReFocus-Conf/3010135

Brazil [69], Andrade J.G. et al. (2013, 2018) in Ethiopia [2]. Libyostrongylus magnus was reported only in South Africa [3], Libyostrongylus magnus was described in the Ukraine in ostriches originating from Ethiopia [1]. Hoberg et al. (1995) [4] were able to re-examine some specimens deposited in the International Institute of Parasitology which was previously identified as Libyostrongylus douglassii in 1933 in Ethiopia. They identified those nematodes as Libyostrongylus magnus. Libyostrongylus magnus (Gilbert, 1937) [1] was described as having long ovejector, but it can be distinguished from Libyostrongylus dentatus by the larger number of eggs inside. Based on the data by Reinecke (1983), Libyostrongylus spp. is considered the most pathogenic nematode, responsible for 50% of the mortality of juvenile birds and occasionally killing adults [5]. Differentiation of these species has become possible because of studies conducted by Ederli et al., which describe the infective larvae of these nematodes. According to the data by Ederli, N.B.; Oliveira, F.C.R, Libyostrongylus douglassii is distributed worldwide and has been found in several countries on five continents, excluding Asia and Antarctica nematodes [3]. Fockema A. et al. (1985) determined Libyostrongylus douglassii (L4 larvae of the nematode) in the proventriculus of ostriches in South Africa in the year of 1985 and treated ostriches with Fenbendazole at dosage rate of 15 mg/kg [3,4]. Hoberg E.P. et al. (1995) gathered specimens of Libyostrongylus sp. at the time of the necropsy from 2 adult ostriches on farms in North Carolina and Texas and made comparisons. During the necropsy of the ostriches, two species of Libyostrongylus sp. were defined; one of them was gravid female specimens of Libyostrongylus douglassii [4]. Sotiraki S.T. et al. (2001) recorded nematode eggs looking like strongylid-type eggs that were characterized as L. douglassii or C. struthionis in fecal samples in Greece, researchers informed that it was not possible to differentiate them at this stage and larval cultures were not performed [3]. Ponce G. F. et al. (2002) also determined the eggs of Libyostrongylus sp. in the feces of ostriches from the Spanish, Netherlands, Belgium and Portuguese. According to the scholar, eggs found in the feces were similar to those of Codiostomum struthionis, a non-pathogenic roundworm. According to the data offered by Cork S.C. (2005), it was not clear how Libyostrongylus spp. arrived in New Zealand, and it was probably entered with live ostrich imports in the 1990s. The nematode, Libyostrongylus douglassii was determined in samples from debilitated ostriches on the North Island farm in May 2004 using in-vitro larval culture and examination of adult parasite morphology [3,4]. British researchers, Ederli N.B. et al. (2008, 2015), examined the proventriculus of 10 ostriches too, and there were both species of Libyostrongylus sp. in all analyzed proventriculus [3]. In 2013, Andrade J.G. et al. focused on investigating the genetic characterization supporting a different evolutionary history of blood-sucking nematodes, including Libyostrongylus douglassii and Libyostrongylus dentatus, for the first time in Brazil [2]. After several years, fecal samples were gathered from wild ostriches (Struthio molybdophanes) in Ethiopia by Andrade J.G. et al. (2018) to verify Libyostrongylus spp. infections. To perform this duty, researchers did a coproculture, and to identify infective larvae, general morphology and morphometry were done [1].