Encephalitic Listeriosis in Small Ruminants in Oman: Pathophysiology,
Antimicrobial Sensitivity and Molecular Characterization
Haytham Ali1,2,ø,*, Hossam G Tohamy3,
Ruqayia Al-Hattali4, Hibatallah Al-Habsi4,
Khalid Al-Habsi1, Elshafie I Elshafie1,5,Aliya
Al-Ansari6 and Mahmoud S El-Neweshy4,7,ø
1Department
of Animal and Veterinary Sciences, College of Agricultural and
Marine Sciences, Sultan Qaboos University, Muscat, Sultanate of
Oman; 2Department of Pathology, Faculty of Veterinary
Medicine, Zagazig University, Zagazig, Egypt; 3Department
of Pathology, Faculty of Veterinary Medicine, Alexandria University,
Alexandria, Egypt; 4Central
Laboratory for Animal Health, Ministry of Agriculture, Fisheries,
and Water ResourcesMuscat
Sultanate of Oman; 5Central
Veterinary Research Laboratory, P.O. Box 8067, Al Amarat, Khartoum,
Sudan; 6Department of Biology, College of Science, Sultan
Qaboos University, Muscat, Sultanate of Oman; 7Department
of Pathology, Faculty of Veterinary Medicine, Kafrelsheikh
University, Kafrelsheikh, Egypt.
Ø Contributed
equally.
*Corresponding author:
h.ali@squ.edu.om
Abstract
Listeriosis is an infectious and fatal disease of
domestic mammals and humans caused by Listeria monocytogenes (L.
monocytogenes). This study discusses the prevalence, pathology,
microbiology, and molecular characterization of reported encephalitic
listeriosis cases in caprine and ovine species in the north of Oman between 2017
and 2019. Thirty suspected small ruminants (goats=20 and sheep=10) were reported
from eight outbreaks in northern Oman during the 3 years. The overall morbidity,
mortality, and case fatality in goats were 5.8, 5.5 and 95%, respectively, while
in sheep, were 8.4, 4.2 and 50%, respectively. Animals under 12 months of age
had a case fatality rate of 100% compared to 50% in animals older
than one year. The
clinical signs in all reported cases were fever, anorexia, deviated
neck, and circling. Necropsied animals showed no
significant gross lesions. Microscopically, microabscesses, hemorrhages, and
perivascular cuffs were observed in the hindbrain along with positive
immunostaining of intracellular L. monocytogens antigens in the
mononuclear and polymorph nuclear cells. Two L. monocytogenes isolates
(A4 and E7) from two goats had multiple antimicrobial-resistant indices
scores of 0.5 and 0.3 respectively which is above the
Krumperman permissible threshold (>0.2), indicating a high-risk source of
contamination by the resistant antibiotics in the study area. Encephalitic
listeriosis was further confirmed through the 16sRNA molecular characterization
and phylogenetic analysis of the two listeria isolates. Here we report two
multidrug-resistant L. monocytogens isolates from goats in Oman, which
pose a serious public health threat to both humans and animals.
To Cite This Article:
Ali H, Tohamy HG, Al-Hattali R, Al-Habsi H, Al-Habsi
K, Elshafie EI, Al-Ansari A and El-Neweshy MS, 2023.
Encephalitic listeriosis in small
ruminants in Oman: pathophysiology, antimicrobial sensitivity, and molecular
characterization. Pak Vet J, 44(1): 87-92.
http://dx.doi.org/10.29261/pakvetj/2023.117