Citation: Ameen, A.M.; Abdulaziz, N.S.; Ghaffar, N.M. Molecular Detection and Associated Risk Factors of Brucella melitensis in Aborted Sheep and Goats in Duhok Province, Iraq. Pathogens 2023, 12, 544. https://doi.org/10.3390/ pathogens12040544 Academic Editor: Valentina Virginia Ebani Received: 26 February 2023 Revised: 21 March 2023 Accepted: 27 March 2023 Published: 1 April 2023 Copyright: © 2023 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https:// creativecommons.org/licenses/by/ 4.0/). pathogens Article Molecular Detection and Associated Risk Factors of Brucella melitensis in Aborted Sheep and Goats in Duhok Province, Iraq Alind M. Ameen 1 , Nadhim S. Abdulaziz 2 and Nacheervan M. Ghaffar 3, * 1 Duhok Veterinary Directorate, Ministry of Agriculture and Water Resources, Duhok 42001, Iraq 2 University of Zakho, Zakho International Road, Duhok 42002, Iraq 3 College of Veterinary Medicine, University of Duhok, Zakho Road, Zakho 42001, Iraq * Correspondence: nacheervan.ghaffar@uod.ac; Tel.: +964-(750)464-2285 Abstract: Brucellosis in sheep and goats has a significant economic and zoonotic impact on the livestock population of Duhok province, Iraq. A total of 681 blood samples from aborted sheep and goats were collected from different flocks in seven districts of Duhok and tested using real-time polymerase chain reaction (RT-PCR). Logistic regression was used for the analysis of the potential risk factors associated with RT-PCR positivity. Results revealed an overall prevalence of 35.45% (CI = 2.57) and 23.8% 18 (CI = 0.44) in sheep and goats, respectively. A statistically significant (p = 0.004) difference in prevalence was found between the two species. RT-PCR detected more positive cases in older-aged animals (OR = 0.7164; p = 0.073). A significant difference was found in RT-PCR positivity in relation to different risk factors, including body condition, treatment taken, and abortion frequency (<0.001). The phylogenetic tree based on the 16S rRNA gene indicated that the isolates belonged to B. melitensis and shared a common ancestor and were genetically related to the United States of America (USA), Greece, China, and Nigeria. This study demonstrates that brucellosis is widely prevalent in the study regions. Therefore, the study suggests the implementation of preventive control measures for brucellosis. Keywords: sheep and goats; B. melitensis; risk factor; RT-PCR 1. Introduction Brucellosis is one of the most important and common bacterial zoonoses. It is widespread worldwide and has major economic and public health significance [1]. Brucel- losis causes substantial losses in domestic animals, mainly sheep, goats, and cows. It is a major zoonotic disease that can cause reproductive disorders in animals. The most common Brucella spp. that cause brucellosis are Brucella abortus (B. abortus) in cattle, Brucella melitensis (B. melitensis) or Brucella ovis (B. ovis) in small ruminants, Brucella suis (B. suis) in pigs, and Brucella canis (B. canis) in dogs [2–4]. These species are Gram-negative coccobacilli, faculta- tive intracellular, non-motile, and non-spore forming bacteria. Currently, with a preference for different hosts, twelve Brucella species have been reported [5]. Brucella is a highly infectious bacterium, as even 10–100 cells are sufficient to cause systemic infection [6,7]. According to the World Health Organization (WHO), Food and Agriculture Organiza- tion (FAO), and World Organization for Animal Health (WOAH), brucellosis is still one of the most important and prevalent zoonoses worldwide. Brucellosis is also classified as one of the seven neglected diseases, due lacking a distinctive clinical presentation in humans [8]. Brucellosis has an important impact on animal industries and human health world- wide. Although brucellosis has been eliminated in many developed countries based on proper prevention and eradication, it remains endemic in large regions, mainly in Africa, the Middle East (including Iraq), the Mediterranean Basin, and the Indian subcontinent. In addition, in some developed countries with limited resources, low income, and frequent Pathogens 2023, 12, 544. https://doi.org/10.3390/pathogens12040544 https://www.mdpi.com/journal/pathogens