Sihem HAMDI

Mrs. Sihem HAMDI

Ecole Nationale de Médecine Vétérinaire de Sidi Thabet, Tunis, Tunisia
orcid

Research Focus & Metrics

Academic Career Length

5Years (2022-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

View All Publications
15 November 2022 in Pathogens
Verified
Journal Article
Open access
PDF file
SHSihem HAMDI
Sihem HAMDI
MMMoez Mhadhbi
Moez Mhadhbi
Mourad Ben SaidMourad Ben Said
Mourad Ben Said
AMAmine Mosbah
Amine Mosbah
GMGharbi Mohamed
Gharbi Mohamed
LMLilia Messadi
Lilia Messadi
We conducted a 5-month-long screening of Anaplasma spp. and Anaplasma ovis infection in sheep from central Tunisia. During this longitudinal study, we investigated the infection dynamics using both direct and indirect assessments validated with a polymerase chain reaction (PCR) as the gold standard method. The experimental design included 84 male lambs aged from 6 to 8 months, and 32 ewes, both chosen randomly from June to November with a periodicity of 2 weeks approximately between June and September, and 1 month between September and November. A total of 9 field visits were carried out in this period during which animals were clinically examined and biological samples were extracted. Thus, a total of 716 blood smears, 698 sera from the nine sampling dates, as well as 220 blood samples from the first and the ninth sampling dates were collected from apparently healthy lambs and ewes, respectively, and analyzed by competitive enzyme-linked immunosorbent assay (cELISA) and polymerase chain reaction (PCR) assay, for the detection of Anaplasma antibodies and A. ovis DNA, respectively. Sera were analyzed by competitive enzyme-linked immunosorbent assay (cELISA) and PCR, for the detection of Anaplasma antibodies and A. ovis DNA, respectively. The Anaplasma spp. initial seroprevalence rate was 33.3% in lambs and 100% in ewes, and it then flowed in an upward trend to reach a maximum of 52.6% in lambs, whereas in ewes, the Anaplasma spp. seroprevalence rate remained unchanged and equal to 100%. Meanwhile, the A. ovis initial molecular prevalence was 22.6% at the first visit and 26.3% at the last visit in lambs, whereas in ewes, the molecular prevalence rates of A. ovis were higher in both the first and the last visit estimated at 100% and 85.7%, respectively. The Kappa coefficient between cELISA and PCR indicated a moderate level of agreement on the first sampling date (0.67) and a low agreement level on the last (0.43). Furthermore, an exploratory data analysis using a multimodal machine learning approach highlighted the underlying pattern of each analytical technique used in this study. In this prospect, we were able to establish the performance of each technique at detecting Anaplasma spp. in sheep. The combination of these approaches should improve the field assessment while promoting a data-based decision in precision epidemiology. The genetic follow-up test relevant to A. ovis msp4 sequences revealed three different genotypes, two of which were previously described in Italy.

11 May 2023 in Preprints.org
Verified
Preprint
Open access
PDF file
SHSihem HAMDI
Sihem HAMDI
LSLimam Sassi
Limam Sassi
MRMourad Rekik
Mourad Rekik
MDMokhtar Dhehibi
Mokhtar Dhehibi
HMHatem Cheikh M’hamed
Hatem Cheikh M’hamed
GMGharbi Mohamed
Gharbi Mohamed
Conservation agriculture (CONS A) is a sustainable agriculture system which is based on rota-tion crops with no tillage. It has various environmental advantages compared to conventional agriculture (CONV A), namely decrease water evaporation, erosion and CO2 emission. We report herein the first study aiming evaluation of the impact of this type of sustainable agri-culture on sheep gastrointestinal parasites. Two lamb groups aged between 6 and ten months were randomly included to graze separately on CONS A and CONV A pastures. Each group was constituted of two batches of three lambs which were followed up for two rearing months during which liveweight, haematological parameters variation and digestive parasites were studied. At the end of the study period, lambs were slaughtered and the carcass yield was determined and a helminthological autopsy was performed on digestive tracts to estimate different parasitological indicators. There was no difference between lambs rearing on CONS A and those rearing on CONV A for all parasite indicators (infestation intensity, abundance and prevalence), the same trend was also obtained for haematological parameters, liveweight evolution and carcass yield. These results prove that there is no impact of the CONS A on the sheep digestive parasitism. Further studies are needed to support these findings on a bigger animal samples and to investigate the impact of this agriculture on other parasites and for other animal species.

21 September 2023 in Frontiers in Veterinary Science
Verified
Journal Article
Open access
SHSihem HAMDI
Sihem HAMDI
LSLimam Sassi
Limam Sassi
MRMourad Rekik
Mourad Rekik
MDMokhtar Dhehibi
Mokhtar Dhehibi
HMHatem Cheikh M'HAmed
Hatem Cheikh M'HAmed
MGMohamed Gharbi
Mohamed Gharbi
Conservation agriculture (CONS A) is a sustainable agriculture system based on crop rotation with no tillage. It has various environmental advantages compared to conventional agriculture (CONV A): decreased water evaporation, erosion, and CO2 emissions. In this first study of its kind, we aim to evaluate the impact of this type of agriculture on sheep gastrointestinal parasites. Two lamb groups aged between 5 and 10 months were randomly included to graze separately on CONS A and CONV A pastures. Each group was composed of two batches of three lambs, and these were followed up for two rearing months. Liveweight, hematological parameter variation, and digestive parasites were studied. At the end of the study period, lambs were slaughtered the carcass yield was determined, and a helminthological autopsy was performed on the digestive tracts of the animals to estimate different parasitological indicators. There was no difference between lambs reared on CONS A and those reared on CONV A for all parasite indicators (infestation intensity, abundance, and prevalence). The same trend was also obtained for hematological parameters, liveweight evolution, and carcass yield. These results prove that there is no impact of CONS A on the sheep's digestive parasitism. Further studies are needed to support these findings on larger animal samples and to investigate the impact of conservation agriculture on other parasite species. Similar studies could also be conducted on ruminant species.