Q fever: A neglected disease of camels in Giza and Cairo Provinces, Egypt

Abstract

Background and aim: Q fever is a zoonotic disease caused by Coxiella burnetii. Cattle, sheep, and goat are the main reservoir of C. burnetii. In Egypt, the epidemiological data about C. burnetii in camels are limited. Therefore, the current study was conducted to identify C. burnetii infection in camels by different molecular tools and to estimate its seropositivity through the detection of anti-C. burnetii antibodies in camel sera.

Materials and methods: Blood samples were collected 112 from camels in Giza and Cairo Provinces, Egypt. All blood samples were screened by trans-quantitative polymerase chain reaction (trans-qPCR) for C. burnetii and positive samples subjected to standard PCR using the superoxide dismutase enzyme coding gene of C. burnetii. Sera of studied camels were examined for the presence of antibodies against C. burnetii using enzyme-linked immunosorbent assay.

Results: Out of 112 camels, 19 were positive for C. burnetii by qPCR with an overall prevalence of 16.9% (18.6% in Giza and 15.1% in Cairo Provinces, respectively). The seroprevalence of anti-C. burnetii IgG antibodies in the examined camels was 4.5% (5/112).

Conclusions: Trans-qPCR assay is a rapid and sensitive tool for the detection of C. burnetii in acute stage. Camels should be considered one of the major reservoirs for C. burnetii in Egypt.

Keywords: Coxiella burnetii; camel; enzyme-linked immunosorbent assay; standard polymerase chain reaction; trans-quantitative polymerase chain reaction.

Figure-1

Amplification plots of suspected Coxiella burnetii using SYBR Green-based quantitative polymerase chain reaction.

Figure-2

A 1.5% agarose gel electrophoresis of Coxiella burnetii polymerase chain reaction using CB1 and CB2 gene. Lane M: 100 bp DNA ladder, lane +ve: control positive, lane −ve: control negative, lane 1 presents 250 bp amplicon of C. burnetii positive sample, while lanes 2 and 3 present C. burnetii negative samples.