Identification, Genotyping and Antimicrobial Susceptibility Testing of Brucella spp. Isolated from Livestock in Egypt

Aman Ullah Khan; Waleed S Shell; Falk Melzer; Ashraf E Sayour; Eman Shawkat Ramadan; Mandy C Elschner; Amira A Moawad; Uwe Roesler; Heinrich Neubauer; Hosny El-Adawy

doi:10.3390/microorganisms7120603

Identification, Genotyping and Antimicrobial Susceptibility Testing of Brucella spp. Isolated from Livestock in Egypt

Microorganisms. 2019 Nov 22;7(12):603. doi: 10.3390/microorganisms7120603.

Authors

Aman Ullah Khan^{1

2

3}, Waleed S Shell⁴, Falk Melzer¹, Ashraf E Sayour⁵, Eman Shawkat Ramadan⁶, Mandy C Elschner¹, Amira A Moawad^{1

2

7}, Uwe Roesler², Heinrich Neubauer¹, Hosny El-Adawy^{1

8}

Affiliations

¹ Institute of Bacterial Infections and Zoonoses, Friedrich-Loeffler-Institut, 07743 Jena, Germany.
² Institute for Animal Hygiene and Environmental Health, Free University of Berlin, 14163 Berlin, Germany.
³ Department of Pathobiology, College of Veterinary and Animal Sciences, 35200 Jhang, Pakistan.
⁴ Central Laboratory for Evaluation of Veterinary Biologics, Agricultural Research Center, 11517 Abbasaia-Cairo, Egypt.
⁵ Department of Brucellosis, Animal Health Research Institute, Agricultural Research Center, 12618 Dokki-Giza, Egypt.
⁶ Animal Reproduction Research Institute, Agricultural Research Center, 12556 Al Ahram-Giza, Egypt.
⁷ Provincial Laboratory, Institute of Animal Health Research, 35516 Mansoura, Egypt.
⁸ Faculty of Veterinary Medicine, Kafr Elsheikh University, 33516 Kafr El-Sheikh, Egypt.

Abstract

Brucellosis is a highly contagious zoonosis worldwide with economic and public health impacts. The aim of the present study was to identify Brucella (B.) spp. isolated from animal populations located in different districts of Egypt and to determine their antimicrobial resistance. In total, 34-suspected Brucella isolates were recovered from lymph nodes, milk, and fetal abomasal contents of infected cattle, buffaloes, sheep, and goats from nine districts in Egypt. The isolates were identified by microbiological methods and matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS). Differentiation and genotyping were confirmed using multiplex PCR for B. abortus, Brucella melitensis, Brucella ovis, and Brucella suis (AMOS) and Bruce-ladder PCR. Antimicrobial susceptibility testing against clinically used antimicrobial agents (chloramphenicol, ciprofloxacin, erythromycin, gentamicin, imipenem, rifampicin, streptomycin, and tetracycline) was performed using E-Test. The antimicrobial resistance-associated genes and mutations in Brucella isolates were confirmed using molecular tools. In total, 29 Brucella isolates (eight B. abortus biovar 1 and 21 B. melitensis biovar 3) were identified and typed. The resistance of B. melitensis to ciprofloxacin, erythromycin, imipenem, rifampicin, and streptomycin were 76.2%, 19.0%, 76.2%, 66.7%, and 4.8%, respectively. Whereas, 25.0%, 87.5%, 25.0%, and 37.5% of B. abortus were resistant to ciprofloxacin, erythromycin, imipenem, and rifampicin, respectively. Mutations in the rpoB gene associated with rifampicin resistance were identified in all phenotypically resistant isolates. Mutations in gyrA and gyrB genes associated with ciprofloxacin resistance were identified in four phenotypically resistant isolates of B. melitensis. This is the first study highlighting the antimicrobial resistance in Brucella isolated from different animal species in Egypt. Mutations detected in genes associated with antimicrobial resistance unravel the molecular mechanisms of resistance in Brucella isolates from Egypt. The mutations in the rpoB gene in phenotypically resistant B. abortus isolates in this study were reported for the first time in Egypt.

Keywords: Brucella; Egypt; antimicrobial resistance; mutation; resistance-associated genes.