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.

Various Inc-type plasmids and lineages of Escherichia coli and Klebsiella pneumoniae spreading blaCTX-M-15,blaCTX-M-1 and mcr-1 genes in camels in Tunisia.

OBJECTIVES: Resistance to extended-spectrum cephalosporins, fluoroquinolones and colistin is under constant scrutiny in food-producing animals worldwide. However, little is known about camels, which provide milk and meat for human consumption, and are attractions for tourists to ride in arid regions. This study assessed the role of camels as potential reservoirs of these resistance determinants. METHODS: Faecal swabs were collected from 232 camels in Tunisia between April 2016 and July 2018. Enterobacteriaceae were detected on MacConkey agar and extended-spectrum ß-lactamase (ESBL)-producers on the same medium supplemented with cefotaxime. Antimicrobial resistance was assessed by disc diffusion, and ESBL-producing isolates were further characterised by phylogrouping (for Escherichia coli, E. coli) and multilocus sequence typing. Genetic support of the blaESBL and mcr-1 genes was identified by plasmid-typing and Southern blot. RESULTS: E. coli were identified in 163 of 232 (70.3%) and Klebsiella pneumoniae (K. pneumoniae) in 16 of 232 (6.9%) of the dominant flora. Three E. coli and one K. pneumoniae (1.3% and 0.4%, respectively) were found on cefotaxime-enriched media. One K. pneumoniae and one E. coli from a tourist farm harboured the blaCTX-M-15 gene on an IncY plasmid, while the two E. coli from the butchery sector displayed the blaCTX-M-15 gene on an IncI1 plasmid and colocalisation of the blaCTX-M-1 and mcr-1 genes on an IncHI2 plasmid. CONCLUSIONS: This study reported ESBL-producing Enterobacteriaceae in Tunisian camels from both tourist and meat-producing sectors. This was the first description of the mcr-1 gene in a meat-producing camel. Although not alarming, this context needs specific attention to avoid camels becoming a bigger reservoir for multidrug-resistant Enterobacteriaceae.

Coxiella burnetii in Tunisian dromedary camels (Camelus dromedarius): Seroprevalence, associated risk factors and seasonal dynamics.

Q fever, caused by Coxiella burnetii, is a zoonotic disease responsible of abortion in ruminants. Few studies have investigated the prevalence of this infection in camels (Camelus dromedarius). The present report aimed to highlight the epidemiological status and identify the risk factors associated with C. burnetii infection in one-humped dromedary that is the most productive livestock species in arid areas. A total of 534 sera of healthy camels were collected in eight governorates from southern and central Tunisia. Samples were tested by an indirect Enzyme linked Immunosorbent Assay (ELISA). Results were analyzed using the Chi-square test and logistic regression. Overall, 237 camels (44%, 95%CI: 0.40-0.49) were seropositive to C. burnetii. Statistical analysis pointed out four potential risk factors associated with infection. A meaningful high seropositivity was observed in female camels with a previous history of abortion (70%) (OR = 4.186, 95%CI: 2.05-8.51). Seroprevalence was higher in aged camels (>10 years-old) (48%) (OR = 2.91, 95%CI: 1.37-6.17). Besides, camels, intended for meat production from small herds showed a high level of infection (52%) (OR = 2.43, 95%CI: 1.3-4.5). Coxiellosis evolved in dromedary herds throughout the year, however infection was significantly important in autumn (60%) (OR = 4.13, 95%CI: 1.86-9.17) and winter (56%) (OR = 5.52, 95%CI: 2.50-12.16). Bioclimatic stage, gender, tick infestation and contact with other ruminants were not risk factors in camel's infection by C. burnetii. Our reports confirm that Tunisian one-humped dromedaries had been exposed to this bacterium and could contribute to its dissemination among farmers and other livestock animals. Furthers studies are required to evaluate the prevalence of Q fever among people professionally exposed like farmers, veterinarians and slaughterhouse workers.