Serological and Molecular Investigation of Brucella Species in Dogs in Pakistan

Abstract

Brucellosis is an important bacterial zoonosis caused by B. abortus and B. melitensis in Pakistan. The status of canine brucellosis caused by B. canis remains obscure. In total, 181 serum samples were collected from stray and working dogs in two different prefectures viz. Faisalabad (n = 87) and Bahawalpur (n = 94). Presence of antibodies against B. canis and B. abortus/B. melitensis was determined using the slow agglutination test (SAT) and ELISA, respectively. Real-time PCR was performed to detect and differentiate Brucella DNA at the species level. In Faisalabad, the serological prevalence was found to be 9.2% (8/87) and 10.3% (9/87) by SAT and ELISA, respectively. Only one of the ELISA positive samples (1.15%) yielded amplification for B. abortus DNA. In Bahawalpur, 63.8% (60/94) samples were found positive by SAT; however, none of the samples was positive by ELISA or by real-time PCR. Location, age (≥1 year) and body condition (weak) were found to be associated with B. canis infection, whereas presence of wounds was found to be associated with B. abortus infection only. These findings point towards a risk of transmission from dog to livestock and humans and vice versa. The study expects to draw the attention of concerned authorities towards infection prevention and animal welfare. This study warrants further epidemiological investigation on brucellosis in pet dogs and their owners. To the best of our knowledge, this is first ever report on B. canis and B. abortus in dogs in Pakistan.

Serological and Molecular Detection of Bovine Brucellosis at Institutional Livestock Farms in Punjab, Pakistan

“…Brucellosis is an established professional health hazard in Pakistan [11,[43][44][45]. Both B. abortus and B. melitensis have been identified [2][3][4][5][46][47][48]. Despite a great influx of brucellosis reporting in the recent past, livestock holders seem to be unaware of the infection [35].…”

“…At the farms level, institutional-owned livestock farms tend to be less susceptible to the infection, maybe because of better screening, culling, hygiene and veterinary health facilitation programs than private livestock farms and a statistically significant difference (p < 0.05) has been reported [21,34,39,41], however disagreement does exist [42]. One of the major causes of brucellosis outbreaks especially at private-owned farms is the breach in biosecurity, i.e., the introduction of carrier animals (i.e., most often subclinical infected animals) into the existing herd without prior screening [4,49]. The infection remains unsuspected until abortion storm occurs and/or animals are screened for brucellosis.…”

“…They are non-spore forming, non-motile, non-hemolytic and facultative intra-cellular living, Gram-negative coccobacilli. Although Brucellae show a certain host preference, e.g., B. abortus prefers bovines and B. melitensis small ruminants, cross-species transmission does occur when different animals are in close contact with each other [1][2][3][4][5][6]. Brucellosis occurs worldwide, especially in developing and tropical countries, whereas North and Central Europe, Australia, New Zealand, Japan, and Canada are considered as being free from conventional brucellosis in domestic animals [7].…”

Epidemiology and Associated Risk Factors for Brucellosis in Small Ruminants Kept at Institutional Livestock Farms in Punjab, Pakistan

“…This genus comprises; B. melitensis, B. abortus, B. suis, B. canis, B. ovis, and B. neotome (classical Brucella species), B. ceti and B. pinipedialis from marine mammals, B. microti from voles, B. inopinata from human females, B. papionis from baboons and recently B. vulpis from red foxes (1)(2)(3)(4)(5)(6). Based upon host preference; B. abortus predominantly infects bovines, B. melitensis small ruminants, B. canis dogs, B. suis pigs, and B. ovis rams, however, infection in non-prefered hosts is transmissible (7)(8)(9). In developing countries, a higher prevalence rate is observed where it causes abortion and retention of fetal membranes (10).…”

Serological and Molecular Investigation of Brucellosis in Breeding Equids in Pakistani Punjab

“…Humans contract brucellosis mainly through consumption of unpasteurized contaminated dairy milk [ 4 ]. “Nonpreferred” hosts (e.g., equids) are susceptible when in close contact with the infected “preferred” hosts [ 5 , 6 , 7 , 8 ]. In domestic ruminants, abortion storms during the last trimester, hyperthermia, and retention of fetal membranes and then intermittent fever, arthralgia, and myalgia in acute cases and neurologic disorders in chronic cases in humans are characteristic signs [ 9 ].…”