Prevalence of Brucella Contamination in Unpasteurized Dairy Products in Sistan Region, Iran, Using PCR Assay
Document Type : Original Article
Authors
1 DVM graduated, Faculty of veterinary medicine, university of Zabol, Zabol, Iran
2 Department of Food Hygiene, Faculty of Veterinary Medicine, University of Zabol, Zabol, Iran
3 Department of Pathobiology, Faculty of Veterinary Medicine, University of Zabol, Zabol, Iran
4 Zabol veterinary office, Sistan and Baluchestan provincial veterinary service, Iranian veterinary organization, Zabol, Iran
10.22084/avr.2025.31331.1011
Abstract
Brucellosis is one of the most widespread zoonotic diseases globally, posing a signi cant public health and economic burden. It is primarily transmitted to humans through the consumption of contaminated milk and raw dairy products, or by direct contact with infected animals. This study aimed to determine the prevalence of Brucella contamination in unpasteurized dairy products sold in the Sistan region, Iran, utilizing the Polymerase Chain Reaction (PCR) method. A total of 175 unpasteurized traditional dairy samples were collected from various distribution centers in Zabol city. These samples included 35 samples each of milk, yogurt, cheese, buttermilk, and ice cream. DNA extraction was performed using the boiling method. Following DNA extraction, PCR was conducted to detect the presence of Brucella bacteria and identify the species, speci cally targeting Brucella abortus and Brucella melitensis. The results revealed that only one sample (0.58% of 175 tested samples) was positive for Brucella. This positive sample was identied as Brucella abortus, and it originated from one of the 35 milk samples analyzed, indicating a prevalence of 2.86% in unpasteurized milk samples.
This low prevalence of Brucella infection in the Sistan region, compared to findings from other past studies in the area, is likely attributable to the recent, systematic, and annual free vaccination campaigns against brucellosis in livestock throughout the Sistan region. These ndings highlight the effectiveness of ongoing vaccination efforts in reducing the spread of brucellosis in the region.
This low prevalence of Brucella infection in the Sistan region, compared to findings from other past studies in the area, is likely attributable to the recent, systematic, and annual free vaccination campaigns against brucellosis in livestock throughout the Sistan region. These ndings highlight the effectiveness of ongoing vaccination efforts in reducing the spread of brucellosis in the region.
Keywords
[1] Ahmadi A, Saadati D, Najimi M, Ganjali H. Com-
parison of PCR and conventional serological meth-
ods for detection of Brucella spp. in ovine and
caprine blood serum. Archives of Razi Institute.
2021 Sep 1;76(3):445.
[2] Al-Khalaf SS, Mohamad BT, Nicoletti P. Control
of brucellosis in Kuwait by vaccination of cattle,
sheep and goats with Brucella abortus strain 19 or
Brucella melitensis strain Rev. 1. Tropical animal
health and production. 1992 Mar;24(1):45-9.
[3] Baily GG, Krahn JB, Drasar BS, Stoker NG. De-
tection of Brucella melitensis and Brucella abortus
by DNA ampli cation. J Trop Med Hyg. 1992 Aug
1;95(4):271-5.
[4] Batrinou A, Strati IF, Tsantes AG, Papa-
paraskevas J, Dimou I, Vourvidis D, Kyrma A,
Antonopoulos D, Halvatsiotis P, Houhoula D.
The importance of complementary PCR analysis
in addition to serological testing for the detec-
tion of transmission sources of Brucella spp. in
Greek Ruminants. Veterinary Sciences. 2022 Apr
17;9(4):193.
[5] Bricker BJ, Halling SM. Differentiation of Brucella
abortus bv. 1, 2, and 4, Brucella melitensis, Bru-
cella ovis, and Brucella suis bv. 1 by PCR. Journal
of clinical microbiology. 1994 Nov;32(11):2660-6.
[6] Dadar M, Bendrey R, Taylor GM, Shahali Y. The
history of brucellosis in the Middle East: insights
for contemporary health challenges. Frontiers in
Microbiology. 2025 May 30;16:1571087.
Prevalence of Brucella Contamination in Unpasteurized Dairy Products in Sistan Region, Iran, Using PCR
Assay: 21{25 24
[7] G lowacka P, Z_ akowska D, Naylor K, Niemcewicz
M, Bielawska-Drozd A. Brucella{virulence factors,
pathogenesis and treatment. Polish journal of mi-
crobiology. 2018 Jun 30;67(2):151.
[8] Golshani M, Buozari S. A review of brucellosis in
Iran: epidemiology, risk factors, diagnosis, con-
trol, and prevention. Iranian biomedical journal.
2017 Nov;21(6):349.
[9] Hull NC, Schumaker BA. Comparisons of bru-
cellosis between human and veterinary medicine.
Infection ecology & epidemiology. 2018 Jan
1;8(1):1500846.
[10] Javadi A, Akrami Nojadeh G, Javadi MR, Ah-
mad Khanli M. A serological survey of ovine
and caprine brucellosis in slaughterhouses of East
Azerbaijan province during 2004. Veterinary Clin-
ical Pathology The Quarterly Scienti c Journal.
2007 May 22;1(1 (1) Spring):15-9.
[11] Kaboutari J, Shari H, Yousefzade A, Mashayekhi
K, Khoshkam M, Afsharipour N. Seroprevalence
of ovine and caprine anti-Brucella antibodies in
south of Kerman province (Iran, 2012). Research
Veterinary of Journal. 2015, 70,4:371-375.
[12] Khurana SK, Sehrawat A, Tiwari R, Prasad M,
Gulati B, Shabbir MZ, Chhabra R, Karthik K,
Patel SK, Pathak M, Iqbal Yatoo M. Bovine
brucellosis{a comprehensive review. Veterinary
Quarterly. 2021 Dec 15;41(1):61-88.
[13] Lai S, Chen Q, Li Z. Human brucellosis: an ongo-
ing global health challenge. China CDC Weekly.
2021 Feb 5;3(6):120.
[14] Liu Z, Gao L, Wang M, Yuan M, Li Z. Long
ignored but making a comeback: a world-
wide epidemiological evolution of human brucel-
losis. Emerging microbes & infections. 2024 Dec
31;13(1):2290839.
[15] Luo B, Wang Q, Yang S, Song X, Li Z. Epidemi-
ological, clinical, and laboratory characteristics of
581 human brucellosis cases in Xinjiang, China.
Frontiers in Microbiology. 2025 May 7;16:1541277.
[16] Mohammadi N, Najimi M, Saadati D, and Tekeh
F. 'Contamination Rate of Aborted Fetal Sheep
with Brucella melitensis. Gonbad-e Qabus Coun-
try. Iranian Journal of Infectious Diseases and
Tropical Medicine, 2019. 24:27-32.
[17] Moussa IM, Omnia ME, Amin AS, Ashgan MH,
Selim SA. Evaluation of the currently used poly-
merase chain reaction assays for molecular detec-
tion of Brucella species. Afr J Microbiol Res. 2011
Jun 18;5(12):1511-20.
[18] Narouei MR, Saadati D, Najimi M, Gangali H,
Shah Karami F. Prevalence and risk factors of
Brucella infection in sheep and goats in the Sis-
tan region by PCR method. Journal of Zoonotic
Diseases. 2022 Jul 1;6(3):129-37.
[19] Qureshi KA, Parvez A, Fahmy NA, Abdel Hady
BH, Kumar S, Ganguly A, Atiya A, Elhassan
GO, Alfadly SO, Parkkila S, Aspatwar A. Bru-
cellosis: epidemiology, pathogenesis, diagnosis
and treatment{a comprehensive review. Annals of
medicine. 2023 Dec 12;55(2):2295398.
[20] Tulu D. Bovine brucellosis: epidemiology, public
health implications, and status of brucellosis in
Ethiopia. Veterinary Medicine: Research and Re-
ports. 2022 Jan 7:21-30.
[21] Zhang N, Huang D, Wu W, Liu J, Liang F, Zhou
B, Guan P. Animal brucellosis control or eradica-
tion programs worldwide: a systematic review of
experiences and lessons learned. Preventive veteri-
nary medicine. 2018 Nov 15;160:105-15.
parison of PCR and conventional serological meth-
ods for detection of Brucella spp. in ovine and
caprine blood serum. Archives of Razi Institute.
2021 Sep 1;76(3):445.
[2] Al-Khalaf SS, Mohamad BT, Nicoletti P. Control
of brucellosis in Kuwait by vaccination of cattle,
sheep and goats with Brucella abortus strain 19 or
Brucella melitensis strain Rev. 1. Tropical animal
health and production. 1992 Mar;24(1):45-9.
[3] Baily GG, Krahn JB, Drasar BS, Stoker NG. De-
tection of Brucella melitensis and Brucella abortus
by DNA ampli cation. J Trop Med Hyg. 1992 Aug
1;95(4):271-5.
[4] Batrinou A, Strati IF, Tsantes AG, Papa-
paraskevas J, Dimou I, Vourvidis D, Kyrma A,
Antonopoulos D, Halvatsiotis P, Houhoula D.
The importance of complementary PCR analysis
in addition to serological testing for the detec-
tion of transmission sources of Brucella spp. in
Greek Ruminants. Veterinary Sciences. 2022 Apr
17;9(4):193.
[5] Bricker BJ, Halling SM. Differentiation of Brucella
abortus bv. 1, 2, and 4, Brucella melitensis, Bru-
cella ovis, and Brucella suis bv. 1 by PCR. Journal
of clinical microbiology. 1994 Nov;32(11):2660-6.
[6] Dadar M, Bendrey R, Taylor GM, Shahali Y. The
history of brucellosis in the Middle East: insights
for contemporary health challenges. Frontiers in
Microbiology. 2025 May 30;16:1571087.
Prevalence of Brucella Contamination in Unpasteurized Dairy Products in Sistan Region, Iran, Using PCR
Assay: 21{25 24
[7] G lowacka P, Z_ akowska D, Naylor K, Niemcewicz
M, Bielawska-Drozd A. Brucella{virulence factors,
pathogenesis and treatment. Polish journal of mi-
crobiology. 2018 Jun 30;67(2):151.
[8] Golshani M, Buozari S. A review of brucellosis in
Iran: epidemiology, risk factors, diagnosis, con-
trol, and prevention. Iranian biomedical journal.
2017 Nov;21(6):349.
[9] Hull NC, Schumaker BA. Comparisons of bru-
cellosis between human and veterinary medicine.
Infection ecology & epidemiology. 2018 Jan
1;8(1):1500846.
[10] Javadi A, Akrami Nojadeh G, Javadi MR, Ah-
mad Khanli M. A serological survey of ovine
and caprine brucellosis in slaughterhouses of East
Azerbaijan province during 2004. Veterinary Clin-
ical Pathology The Quarterly Scienti c Journal.
2007 May 22;1(1 (1) Spring):15-9.
[11] Kaboutari J, Shari H, Yousefzade A, Mashayekhi
K, Khoshkam M, Afsharipour N. Seroprevalence
of ovine and caprine anti-Brucella antibodies in
south of Kerman province (Iran, 2012). Research
Veterinary of Journal. 2015, 70,4:371-375.
[12] Khurana SK, Sehrawat A, Tiwari R, Prasad M,
Gulati B, Shabbir MZ, Chhabra R, Karthik K,
Patel SK, Pathak M, Iqbal Yatoo M. Bovine
brucellosis{a comprehensive review. Veterinary
Quarterly. 2021 Dec 15;41(1):61-88.
[13] Lai S, Chen Q, Li Z. Human brucellosis: an ongo-
ing global health challenge. China CDC Weekly.
2021 Feb 5;3(6):120.
[14] Liu Z, Gao L, Wang M, Yuan M, Li Z. Long
ignored but making a comeback: a world-
wide epidemiological evolution of human brucel-
losis. Emerging microbes & infections. 2024 Dec
31;13(1):2290839.
[15] Luo B, Wang Q, Yang S, Song X, Li Z. Epidemi-
ological, clinical, and laboratory characteristics of
581 human brucellosis cases in Xinjiang, China.
Frontiers in Microbiology. 2025 May 7;16:1541277.
[16] Mohammadi N, Najimi M, Saadati D, and Tekeh
F. 'Contamination Rate of Aborted Fetal Sheep
with Brucella melitensis. Gonbad-e Qabus Coun-
try. Iranian Journal of Infectious Diseases and
Tropical Medicine, 2019. 24:27-32.
[17] Moussa IM, Omnia ME, Amin AS, Ashgan MH,
Selim SA. Evaluation of the currently used poly-
merase chain reaction assays for molecular detec-
tion of Brucella species. Afr J Microbiol Res. 2011
Jun 18;5(12):1511-20.
[18] Narouei MR, Saadati D, Najimi M, Gangali H,
Shah Karami F. Prevalence and risk factors of
Brucella infection in sheep and goats in the Sis-
tan region by PCR method. Journal of Zoonotic
Diseases. 2022 Jul 1;6(3):129-37.
[19] Qureshi KA, Parvez A, Fahmy NA, Abdel Hady
BH, Kumar S, Ganguly A, Atiya A, Elhassan
GO, Alfadly SO, Parkkila S, Aspatwar A. Bru-
cellosis: epidemiology, pathogenesis, diagnosis
and treatment{a comprehensive review. Annals of
medicine. 2023 Dec 12;55(2):2295398.
[20] Tulu D. Bovine brucellosis: epidemiology, public
health implications, and status of brucellosis in
Ethiopia. Veterinary Medicine: Research and Re-
ports. 2022 Jan 7:21-30.
[21] Zhang N, Huang D, Wu W, Liu J, Liang F, Zhou
B, Guan P. Animal brucellosis control or eradica-
tion programs worldwide: a systematic review of
experiences and lessons learned. Preventive veteri-
nary medicine. 2018 Nov 15;160:105-15.
)