First report of Chlamydophila abortus infection in the dromedary camel (Camelus dromedarius) population in eastern Algeria

Chlamydiosis in Animals

The Chlamydiaceae family consists of Gram-negative, obligate intracellular bacteria that replicate within the cells of a diverse range of hosts. These hosts include domesticated animals such as cats, dogs, and livestock, as well as wildlife like koalas and birds, exotic species such as reptiles and amphibians, and humans. Chlamydial infection can result in various clinical signs, including respiratory diseases, reproductive failures, ocular pathologies, and enteritis, though the infected organism may remain asymptomatic. In recent years, chlamydial nomenclature has undergone several revisions due to the wide range of hosts, the frequent discovery of novel strains, and the reclassification of existing ones. Given this and the clinical significance of these infections, ranging from asymptomatic to fatal, an updated review is essential. This article outlines key characteristics of Chlamydia species and provides an updated overview of their nomenclature, offering a concise reference for future research on chlamydial diseases.

The one-humped camel: The animal of future, potential alternative red meat, technological suitability and future perspectives

The 2020 world population data sheet indicates that world population is projected to increase from 7.8 billion in 2020 to 9.9 billion by 2050 (Increase of more than 25%). Due to the expected growth in human population, the demand for meats that could improve health status and provide therapeutic benefits is also projected to rise. The dromedary also known as the Arabian camel, or one-humped camel ( Camelus dromedarius), a pseudo ruminant adapted to arid climates, has physiological, biological and metabolic characteristics which give it a legendary reputation for surviving in the extreme conditions of desert environments considered restrictive for other ruminants. Camel meat is an ethnic food consumed across the arid regions of Middle East, North-East Africa, Australia and China. For these medicinal and nutritional benefits, camel meat can be a great option for sustainable meat worldwide supply. A considerable amount of literature has been published on technological aspects and quality properties of beef, lamb and pork but the information available on the technological aspects of the meat of the one humped camel is very limited. Camels are usually raised in less developed countries and their meat is as nutritionally good as any other traditional meat source. Its quality also depends on the breed, sex, age, breeding conditions and type of muscle consumed. A compilation of existing literature related to new technological advances in packaging, shelf-life and quality of camel meat has not been reviewed to the best of our knowledge. Therefore, this review attempts to explore the nutritional composition, health benefits of camel meat, as well as various technological and processing interventions to improve its quality and consumer acceptance. This review will be helpful for camel sector and highlight the potential for global marketability of camel meat and to generate value added products.

Serosurvey and associated risk factors for Chlamydia abortus infection in Dromedary camels in Egypt

Chlamydia abortus (C. abortus) is a gram-negative, obligate intracellular bacterium that causes major public health problems in human and reproductive problems in animals. The information about the epidemiology of this pathogen among camels in Egypt is very rare. This study aimed to evaluate the existence of antibodies against C. abortus in camels and assess the related risk factors for infection. A total of 410 blood samples were collected from camels from three Egyptian governorates and examined using commercial ELISA kit. The overall seroprevalence rate was 6.6% and the higher C. abortus seropositivity rate was found in Giza governorate. Location, sex and infestation by ectoparasites did not influence on the seroprevalence of the disease. In addition, age, herd size, contact with small ruminants and history of abortion were identified as risk factors for C. abortus infection according to the univariate analysis. Based on multivariate analysis, age group of 4-8 years, small herd size, contact of camels with sheep and goats, and history of abortion were found to be significant risk factors for chlamydiosis transmission in camels. These factors had odds ratios of 4.23, 3.51, 2.84, and 2.5, respectively. These results suggest that camels have a role in the epidemiology of C. abortus infection. This promotes awareness and severe public health concern about infectious camel illnesses, allowing for additional diagnostic advancements and effective management techniques to be developed.

Serological and molecular survey of brucellosis and chlamydiosis in dromedary camels from Tunisia

The present sero-epidemiological survey was designed and conducted to scrutinize the current status of camel-related brucellosis and chlamydiosis in Tunisia. Whole blood and serum samples were collected from 470 dromedaries (Camelus dromedarius) from eight different Tunisian governorates. Serum samples were subjected to indirect enzyme-linked immunosorbent assay (iELISA). The detection of Brucella and Chlamydia DNA was performed using conventional PCR targeting the bcsp-31 and 16 S rRNA gene, respectively. Overall, 10/470(2.12%) and 27/470 (5.75%) camels were revealed seropositive to Brucella and Chlamydia, respectively. Multivariate logistic regression analysis showed different risk factors associated with these infections. Meaningful high rates of seropositivity of brucellosis (9.5%; p = 0.000; OR=64.193) and chlamydiosis (22.6%; p = 0.000; OR=42.860) were noted among camels showing previous abortions in particular for aged females. Besides, Chlamydia seropositivity is significantly important during winter (12.5%; p = 0.009; OR= 27.533), and in camels raised in small farms (11.4%, p = 0.000, OR=86.052). Molecular analysis revealed no positivity from all analyzed blood samples. These findings indicate the involvement of camels in the epidemiology of these abortive infectious diseases. This raises awareness and serious public health concern for infectious camel diseases in order to develop further diagnostic improvements and effective control strategies.

Recent advances and public health implications for environmental exposure to Chlamydia abortus: from enzootic to zoonotic disease

Environmental transmission of Chlamydia abortus as a result of enzootic disease or disease outbreaks and the threats posed by this pathogen has been previously reported, however a state-of-the-science review of these reports and the identification of future research priorities in this area is still lacking. This study provides an overview of the current knowledge of host–pathogen–environment interactions, addressing public health risks and identifying critical questions and research gaps. We performed a systematic PubMed and Web of Science search for publications related to Chlamydia abortus in the past four decades, and we reviewed and combined the evidence critically discussing and commenting the results. A total of 182 studies, 5 chapters of specific books and the “OIE terrestrial manual” were included in this review. There were substantial variations between the studies in topic addressed and experimental design. Overall, the literature largely supports the crucial role played by environmental exposure on the acquisition of zoonotic disease caused by Chlamydia abortus. We also identify the paucity of information related to interspecies transmission and pathogen adaptation in relation to environmental dissemination and zoonotic risk. This analysis further highlights the need for additional research given that environmental transmission represents a serious risk not only to susceptible patients (pregnant women and immunocompromised individuals), but also for other species including wildlife.

Seroprevalence and Risk Factors Associated with Chlamydia abortus Infection in Sheep and Goats in Eastern Saudi Arabia

Chlamydia abortus (C. abortus) is intracellular, Gram-negative bacterium that cause enzootic abortion in sheep and goats. Information on C. abortus seroprevalence and flock management risk factors associated with C. abortus seropositivity in sheep and goats in Saudi Arabia are scarce. The objectives of this study were to (i) estimate the animal, flock, and within-flock seroprevalence of C. abortus among Eastern Province sheep and goat flocks and (ii) identify the flock management and animal risk factors associated with C. abortus seropositivity in Eastern Province, Saudi Arabia. A cross-sectional study with a two-stage sampling process was carried out in the Eastern Province, Saudi Arabia, between 2015 and 2016. A total of 1717 sheep and 1101 goat serum samples were collected from 21 sheep and 14 goat flocks, then were tested for C. abortus antibodies using a commercial ELISA Kit. In addition, vaginal swabs and aborted tissue samples were collected from sheep (n = 48) and goats (n = 15) with recent history of abortion for detection of C. abortuspmp gene using PCR. A questionnaire was constructed to collect information about flock management and animal risk factors possibly associated with C. abortus infection in sheep and goats. The true sheep and goat-level seroprevalences were 11.1% (95% CI: 9.7–12.7) and 10.6% (95% CI: 8.8–12.5), respectively. The true flock-level seroprevalence was 100% for both sheep and goats. However, the average within sheep and goat flocks true seroprevalences were 9.6% (95% CI: 1.8–22.9) and 9.3% (95% CI: 1.8–19.5), respectively. Multivariable logistic regression revealed that introduction of new sheep to the flocks (OR = 2.6; 95% CI: 1.5–4.4), type of breeding system (OR = 1.8; 95% CI: 1.0–3.4), flocks allowing females in (OR = 1.9; 95% CI: 1.1–3.3) or females out (OR = 2.2; 95% CI: 1.1–4.3), and sheep age 1.4–2.8 years (OR = 1.9; 95% CI: 1.3–2.9) were potential risk factors for C. abortus seropositivity in sheep flocks. However, in goat flocks, the introduction of new goats to the flocks (OR: 1.9; 95% CI: 1.2–3.0) was identified as a risk factor, whereas good farm hygiene (OR: 0.3; 95% CI: 0.2–0.7) was identified as a protective factor. C. abortus pmp gene was identified in 45 (93.8%) and 15 (100%) of samples collected from sheep and goats, respectively. These results could be used to implement efficient management measures to prevent and control C. abortus infection in sheep and goats in Eastern Province, Saudi Arabia, but also could be used to reduce the risk of C. abortus infection in sheep and goat flocks with similar management practices in other regions.