First molecular characterization of Cryptosporidium in Yemen N. A. ALYOUSEFI 1 , M. A. K. MAHDY 1,2 *, Y. A. L. LIM 1 , L. XIAO 3 and R. MAHMUD 1 1 Department of Parasitology, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia 2 Department of Parasitology, Faculty of Medicine, Sana’a University, Sana’a, Yemen 3 Division of Foodborne, Waterborne and Environmental Diseases, National Center for Emerging and Zoonotic Infectious Diseases, Centers for Disease Control and Prevention, Atlanta, GA, USA (Received 4 August 2012; revised 23 September and 10 October 2012; accepted 15 October 2012; first published online 1 February 2013) SUMMARY Cryptosporidium is a protozoan parasite of humans and animals and has a worldwide distribution. The parasite has a unique epidemiology in Middle Eastern countries where the IId subtype family of Cryptosporidium parvum dominates. However, there has been no information on Cryptosporidium species in Yemen. Thus, this study was conducted in Yemen to examine the distribution of Cryptosporidium species and subtype families. Fecal samples were collected from 335 patients who attended hospitals in Sana’a city. Cryptosporidium species were determined by PCR and sequence analysis of the 18 s rRNA gene. Cryptosporidium parvum and C. hominis subtypes were identified based on sequence analysis of the 60 kDa glycoprotein (gp60) gene. Out of 335 samples, 33 (9·9%) were positive for Cryptosporidium. Of them, 97% were identified as C. parvum whilst 1 case (3%) was caused by C. hominis. All 7 C. parvum isolates subtyped belonged to the IIaA15G2R1 subtype. The common occurrence of the zoonotic IIa subtype family of C. parvum highlights the potential occurrence of zoonotic transmission of cryptosporidiosis in Yemen. However, this postulation needs confirmation with future molecular epidemiological studies of cryptosporidiosis in both humans and animals in Yemen. Key words: Cryptosporidium, genotyping, subtyping, Yemen. INTRODUCTION Cryptosporidium is a protozoan parasite in humans and animals and has a worldwide distribution. Cryptosporidium infection has been implicated as a cause of multiple waterborne and foodborne out- breaks of diarrhoea (MacKenzie et al. 1994; Fayer et al. 2000; Slifko et al. 2000). Humans can also acquire the infection through direct contact with humans (anthroponotic transmission) or animals (zoonotic transmission). Although cryptosporidiosis causes self-limiting diarrhoea in immunocompetent persons, it may lead to life-threatening diarrhoea in immunocompromised patients (DuPont et al. 1995; Kjos et al. 2005). The disease has also been considered as a predictor of malnutrition in early childhood (Huang and White, 2006). The genus Cryptosporidium is a multispecies complex. To date, approximately 27 species and more than 60 genotypes have been identified (Fayer and Santin, 2009; Fayer, 2010; Traversa, 2010; Elwin et al. 2012). Most of the species or genotypes infect a particular host with a few notable exceptions. Cryptosporidium parvum infects humans and several species of animals, and is the major species respon- sible for zoonotic cryptosporidiosis in many devel- oped countries. Another species, C. hominis, commonly infects humans and is responsible for anthroponotic transmission, with high prevalence in developing countries compared with industrial nations (Raccurt, 2007; Xiao, 2009). Subtyping of C. parvum based on 60 kDa glycoprotein (gp60) gene identified at least 12 subtype families (IIa – IIl). The zoonotic IIa subtype is predominant in developed nations and rarely isolated from humans in developing nations where the anthroponotic IIc subtype family is the most common cause of human C. parvum infec- tions. The C. parvum IIa subtype family has a high genetic diversity with IIaA15G2R1 being predomi- nant in calves and the major subtype infecting human and cattle in some countries (Xiao, 2009, 2010). The epidemiology of Cryptosporidium in Middle Eastern countries is different from other developing countries as earlier studies reported that C. parvum had higher prevalence than C. hominis in Saudi Arabia (Al-Brikan et al. 2008), Kuwait (Sulaiman et al. 2005), Jordan (Hijjawi et al. 2010), Turkey (Tamer et al. 2007), and Iran (Nazemalhosseini- Mojarad et al. 2011). However, in nearby Egypt, C. hominis was more prevalent than C. parvum (Eida et al. 2009; Abd El Kader et al. 2011). Subtype analysis based on gp60 has shown that the IId subtype family is the predominant subtype in Middle Eastern countries whereas the IIc subtype family is the dominant C. parvum in developing countries (Xiao, 2010). In Yemen, cryptosporidiosis is an endemic disease with prevalence ranging from 1% to 50% (Al-Shibani et al. 2009; Al-Shamiri et al. 2010; Alyousefi et al. * Corresponding author: Department of Parasitology, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia. E-mail: alsharaby9@yahoo.com 729 Parasitology (2013), 140, 729–734. © Cambridge University Press 2013 doi:10.1017/S0031182012001953