Tunisian Toxoplasma gondii strains genotyping by the use of AK69 marker

<p>Abstract</p> <p>Background</p> <p>Clinical manifestation due to infection by <it>Toxoplasma gondii </it>is closely linked to the infecting strain of the parasite. Several genetic markers are available to determinate its genotype but few of them are able to discriminate between the three predominant lineages, namely types I, II and III. The number of markers decreases when atypical, recombinant/mixed genotypes need to be identified.</p> <p>Findings</p> <p>In our study, the contribution of sequence polymorphisms in the AK69 gene as typing markers for <it>T. gondii </it>was investigated for the first time in an epidemiological study. The coding region of the marker was amplified, sequenced and aligned for different <it>Toxoplasma </it>strains. The identified nucleotide polymorphism at 12 positions was able to highly discriminate between the different congenital toxoplasmosis Tunisian strains. Moreover the high detection sensitivity level of the marker enabled unambiguous identification of mixed/recombinant genotypes directly.</p> <p>Conclusion</p> <p>It can be, thus, very useful for direct typing in areas where such genotypes are frequently encountered, mainly in the African continent.</p

Survey of the parasite Toxoplasma gondii in human consumed ovine meat in Tunis City.

International audienceToxoplasmosis has been recognized as parasitic zoonosis with the highest human incidence. The human infection by the parasite can lead to severe clinical manifestations in congenital toxoplasmosis and immunocompromised patients. Contamination occurs mainly by foodborne ways especially consumption of raw or undercooked meat. In contrast to other foodborne infections, toxoplasmosis is a chronic infection which would make its economic and social impact much higher than even previously anticipated. Ovine meat was advanced as a major risk factor, so we investigated its parasite survey, under natural conditions. Serological MAT technique and touchdown PCR approaches were used for prevalence determination of the parasite in slaughtered sheep intended to human consumption in Tunis City. The genotyping was carried by SNPs analysis of SAG3 marker. Anti-Toxoplasma antibodies were present in 38.2% of young sheep and in 73.6% of adult sheep. Molecular detection revealed the contamination of 50% of ewes' tissue. Sequencing and SNPs analysis enabled unambiguous typing of meat isolates and revealed the presence of mixed strains as those previously identified from clinical samples in the same area. Our findings conclude that slaughtered sheep are highly infected, suggesting them as a major risk factor of Toxoplasma gondii transmission by meat consumption. Special aware should target consequently this factor when recommendations have to be established by the health care commanders

Seroprevalence of Toxoplasma gondii infection among horses in Tunisia.

International audienceBACKGROUND: The present study was conducted to investigate the serological survey of Toxoplasma antibodies in local.horses from three major regions: a neighbourhood of a city in the North (Sidi Thabet), a neighbourhood of a city on the coast (Monastir) and a neighbourhood of a city in the middle (Battan) of Tunisia (North of Africa). METHODS: A total of 158 serum samples were obtained from clinically healthy horses which consisted of 111 (32 female, 79 male) 2-10 years old and 47 (11 female, 36 male) older than 10 years. All of the horses were tested for antibodies to T. gondii using the Modified Agglutination Test (MAT). RESULTS: According to MAT results, antibodies to T. gondii were found in 28 (17.7%) of 158 sera with the titers of 1:20 in 20 horses, 1:40 in 1 horse, 1:80 in 2 horses, 1:160 in 2 horses, 1:320 in 1 horse and ≥1:640 in 2 horses. Anti-T. gondii antibodies were found in 18 (16.2%) of 111 horses (2-10 years old) and 10 (21.2%) of 47 horses (older than 10 years old). Six (13.9%) out of 43 female had anti-toxoplasma antibodies and 22 (19.1%) from 115 males remained positive. CONCLUSION: Statistically significant differences in age groups and genders were observed between the seropositive and seronegative horses using the Chi square X(2) test. Other statistical correlation was also reported concerning horse breed

A new IgG immunoblot kit for diagnosis of toxoplasmosis in pregnant women.

International audienceThe determination of the accurate immune status of pregnant women is crucial in order to prevent congenital toxoplasmosis. Equivocal results with conventional serological techniques are not uncommon when IgG titers are close to the cut-off value of the test, so that a confirmatory technique is needed. For this purpose, we developed a homemade immunoblot (IB) using soluble extract of Toxoplasma gondii tachyzoites and assessed it by testing 154 positive, 100 negative, and 123 equivocal sera obtained from pregnant women. In order to select the more valuable bands in terms of sensitivity and specificity, we used the Youden Index (YI). The highest YIs were those given by the 32, 36, 98, 21, and 33 bands. The simultaneous presence on the same blot of at least 3 bands showed a much higher YI (0.964) and was adapted as the positivity criterion. The analysis of results showed that our homemade IB correlated well with the commercial LDBIO Toxo II IgG® kit recently recommended as a confirmatory test (96.7% of concordance)

[Relapse of Plasmodium malariae malaria 20 years after living in an endemic area].

International audienceINTRODUCTION:Malaria has been eradicated in Tunisia since 1979. Although it continues to be evoked in the case of fever after travel to an endemic zone, its diagnosis is however difficult during relapses, notably when they are delayed.OBSERVATION:A 50 year-old man having lived in Mauritania from 1978 to 1982 was hospitalized for interstitial pneumopathy and urarthritis. In spite of treatment with broad spectrum antibiotics, the fever accompanied by abundant sweating persisted. A thick blood drop and blood smear was requested and led to the diagnosis of Plasmodium malariae malaria.DISCUSSION:This observation recalls the possibility of parasitic upsurge of some plasmodial species. It should prompt physicians to be careful and evoke malaria in the case of fever in subjects having stayed, even several years before, in an endemic zone. This would permit early diagnosis and treatment

Multiscale predictability of Cutaneous Leishmaniasis in Morocco and Tunisia through the AMO-NAO coupling and its modulation of regional rainfall

Posted January 17, 2024 on medRxiv.The development of effective Early Warning Systems (EWS) for climate-driven zoonotic diseases has been hindered by a lack of predictors with adequate lead time for effective interventions. Atmosphere-Ocean coupled phenomena present predictability beyond the atmospheric deterministic limits and therefore are potentially useful climate drivers to be integrated in mathematical models. While the El Niño-Southern Oscillation (ENSO) has been used to forecast disease dynamics in equatorial and tropical regions, there is a lack of similar applications for temperate areas, likely because of the perceived unpredictability of atmospheric systems such as the North Atlantic Oscillation (NAO). This study challenges this notion by establishing a connection between the NAO and its oceanic counterpart, the Atlantic Multidecadal Oscillation (AMO), revealing common low-frequency components that strongly modulate Cutaneous Leishmaniasis (CL) in Northern Africa. We demonstrate not only short-term couplings, such as the known NAO’s impact on seasonal rainfall, which subsequently affects CL incidence, but we also uncover a significant lagged effect of approximately three years on rainfall and four years on CL incidence. Our findings reveal a unified, multiscale mechanism that influences CL epidemiology across different time scales, underscoring the predictive skill for short and long term time frames, which should be integrated in CL forecasting models

Electrophoretic pattern of the direct PCR on sheep hearts.

<p>C- corresponds to negative control of PCR; MW: 100bp ladder; 1–9: amplification of different sheep isolates and C+ corresponds to the positive control of the reaction.</p

Table 1. Summary of antibodies prevalence.

<p>Ni: Initial number of tested serums; N+: Number of sera with positive reaction; N–: Number of sera with negative reaction; %: percentage of seroprevalence.</p