Veterinary Parasitology 187 (2012) 431–435 Contents lists available at SciVerse ScienceDirect Veterinary Parasitology jo u rn al hom epa ge : www.elsevier.com/locate/vetpar Point mutations in the Theileria annulata cytochrome b gene is associated with buparvaquone treatment failure Hassan Sharifiyazdi a , Fatemah Namazi b , Ahmad Oryan b,∗ , Reza Shahriari c , Mostafa Razavi b a Department of Clinical Sciences, School of Veterinary Medicine, Shiraz University, Shiraz, Iran b Department of Pathobiology, School of Veterinary Medicine, Shiraz University, Shiraz, Iran c Veterinary Organization, Shiraz Branch, Shiraz, Iran a r t i c l e i n f o Article history: Received 2 June 2011 Received in revised form 31 December 2011 Accepted 6 January 2012 Keywords: Theileriosis Theileria annulata cytochrome b gene Mutation Buparvaquone pathology PCR a b s t r a c t Theileriosis is an economically important haemoprotozoal disease with high morbidity and mortality in cattle. Buparvaquone is very effective in the treatment of Theileria infections in cattle. The present study reported an outbreak of bovine tropical theileriosis in Fars Province, southern Iran with buparvaquone treatment failure associated with mutations in drug-binding sites of its causative agent. The infected animals (n = 8) exhibited poor condition, fever, anemia, rough coat and superficial lymph node enlargement. Both blood smears and lymph nodes punctures were positive and further molecular examination revealed that these animals were infected with Theileria annulata. Death occurred in seven of the eight infected animals in spite of the buparvaquone treatment. At molecular study, two types of important single-base muta- tions were observed in the cytochrome b gene of the parasite. These changes resulted in amino acid mutations in the parasite cytochrome b from serine (AGT) 109 to glycine (GGT) for the six dead cases and proline (CCT) 233 to serine (TCT) for one dead case within strongly Q o drug-binding sites. In contrast, neither of these mutations was found in the parasite cytochrome b for the buvarvaquone-treated animal. It seems that these mutation sites are associated with resistance to buparvaquone, a hydroxynaphthoquinone compound. © 2012 Elsevier B.V. All rights reserved. 1. Introduction Bovine theileriosis is transmitted by several species of Hyalomma (Robinson, 1982) and cause acute anemia and icterus with high mortality and morbidity. Theileriosis is highly prevalent in Africa, southern Europe, the Near East and Far East and Central Asia (Brown, 1990, 1997) and threatens an estimated 250 million cattle. The diagnosis of clinical theileriosis is usually based on detection of the macroschizont-infected leukocytes in Giemsa-stained lymph node biopsy smears or the presence of the piroplasms in the peripheral blood smears ∗ Corresponding author. Tel.: +98 7112286950; fax: +98 7112286940. E-mail address: oryan@shirazu.ac.ir (A. Oryan). (Anon, 2008). The molecular techniques seems to be more sensitive, as well as being more specific for diagnosis when compared with other methods (Ilhan et al., 1998; Shayan et al., 1998; Leemans et al., 1999; Gubbels et al., 1999; Martin-Sanchez et al., 1999), and may therefore facilitate determination of latent infections (Aktas et al., 2006; ˙ Ic ¸ a et al., 2007). In the endemic areas, the affected indigenous cattle breeds present, mainly, a subacute condition and are resis- tant to re-infection upon recovery. Imported breeds or crossbred animals are more susceptible with high mortal- ity (Brown, 1990; Preston et al., 1992). Nazifi et al. (2010) showed that the Iranian indigenous cattle in compari- son with Holsteins had a lower parasitemia rate, weaker response to Theileria annulata infection and significantly lower levels of acute phase proteins. The mortality rate 0304-4017/$ – see front matter © 2012 Elsevier B.V. All rights reserved. doi:10.1016/j.vetpar.2012.01.016