دانلود رایگان ترجمه مقاله روش های تشخیصی بیماری تب مالت (نشریه Omicsonline 2016)

یک بررسی در مورد روش های تشخیصی بیماری تب مالت

A Review on Diagnostic Methods of Brucellosis

Abstract

We reviewed different diagnostic methods of brucellosis in different livestock and humans. Bacteriological diagnosis, immunohistochemistry (an alternative technique for direct diagnosis) and different molecular methods for Brucella species genotyping are among the direct methods for diagnosis of brucellosis discussed in this review. The well-established indirect methods for diagnosis of brucellosis, serological and brucellin allergic skin tests were also critically conferred. Finally, for effective control and prevention of brucellosis around the world, the direct diagnostic methods are advised in order to develop vaccine against the circulating Brucella strain in the specific country.

1 Introduction

Brucellosis is an ancient disease that can possibly be traced back to the 5th plague of Egypt around 1600 BC. Recent examination of the ancient Egyptian bones, dating to around 750 BC, showed evidence of sacroilitis and other osteoarticular lesions, common complications of brucellosis [1]. David Bruce isolated Brucella melitensis (B. melitensis) (Micrococcus melitensis at that time) in 1887 from the spleen of a British soldier who died from a febrile illness (Malta fever) common among military personnel stationed on Malta. For almost 20 years aіer isolation of M. melitensis, Malta fever remained a mystery and was thought to be a vector-borne disease until Нemistocles Zammit accidentally demonstrated the zoonotic nature of the disease in 1905 by isolating B. melitensis from goat’s milk. It was believed that goats were not the source of infection since they did not become ill when inoculated with Brucella cultures. Нe discovery that healthy goats could be carriers of the disease has been termed one of the greatest advances ever made in the study of epidemiology [2,3].

Brucellosis is caused by Gram-negative coccobacilli of the genus Brucella [4,5]. In livestock, the disease results in significant economic losses due to reproductive impairment caused by abortion, stillbirth or weak calves and neonatal mortality, infertility [6]. In humans, Brucella spp. infection causes a febrile disease that may be associated with a broad spectrum of symptoms, and it may be fatal in some cases [5,7]. Currently, there are ten spp. described in the genus Brucella. Each one may infect diوٴerent host spp., but each Brucella spp. has a preference for its host spp., B. melitensis (sheep and goats), B. abortus (cattle), B. suis (pigs), B. ovis (rams), B. canis (dogs), B. microti (rodents-Microtus arvalis), B. neotomae (rodents – Neotoma lepida), B. pinnipedialis (pinnipeds), B. ceti (cetacea), and B. inopinata (originally isolated from a human patient, but its preferential host is not known) [8,9]. Нree of this Brucella spp. can be subdivided in biotypes [10,11].

Нerefore, three biotypes (1-3) have been identified in B. melitensis; eight biotypes (1-7,9) in B. abortus; and five biotypes (1-5) in B. suis [12]. All Brucella spp. are considered potentially pathogenic for humans, with the exceptions of B. neotomae, B. microti, and B. ovis [6,9].

A precise diagnosis of Brucella spp. infection is important for the control of the disease in animals and consequently in man. Clinical diagnosis is based usually on the history of reproductive failures in livestock, but it is a presumptive diagnosis [13] that must be confirmed by laboratory methods [13,14]. Нe “gold standard” in the diagnosis of brucellosis is bacterial isolation from blood or bone marrow specimens that requires long cultivation periods (4 to 7 days up to 40 days) and oіen the blood cultures are unsuccessful [15]. Serological tests, such as serum agglutination test (SAT), rose Bengal plate test (RBPT), complement fixation test (CFT), and enzyme-linked immunosorbent assay (ELISA) are still frequently used [5,16]. Since the routine identification and diوٴerentiation of brucellosis suspected specimens, based on culture isolation and phenotypic characterization, requires biosafety level-3 (BSL-3) protocols for the high risk of laboratoryacquired infections [17], molecular methods have been explored in order to overcome these diٹculties. Furthermore, the polymerase chain reaction (PCR)-based assays have shown a higher sensitivity with respect to the standard microbiological assay for the diagnosis of brucellosis [18].

Нerefore, the objectives of this paper are to review a diagnostic methods that are used for isolation, screening, monitoring or epidemiological surveillance and complementary or confirmatory for brucellosis in livestock and humans.