Activated sludge and UV-C254 for Sapovirus, Aichivirus, Astrovirus, and Adenovirus processing

In this study, the detection rates of four enteric viruses, Human Astrovirus (HAstVs), Aichivirus (AiVs), Human Adenovirus (HAdVs), and Sapovirus (SaVs) are carried out to assess the virological quality of the treated wastewater. A total of 140 samples was collected from wastewater treatment plant WWTP of Tunis-City. Real-time RT-PCR and conventional RT-PCR results showed high frequencies of detection of the four enteric viruses investigated at the entry and exit of the biological activated sludge procedure and a significant reduction in viral titers after tertiary treatment with UV-C254 irradiation. These results revealed the ineffectiveness of the biological activated sludge treatment in removing viruses and the poor quality of the treated wastewater intended for recycling, agricultural reuse, and safe discharge into the natural environment. The UV-C254 irradiation, selected while considering the non-release of known disinfection by-products because of eventual reactions with the large organic and mineral load commonly present in the wastewater.

Epidemiological Analyses of the First Incursion of the Epizootic Hemorrhagic Disease Virus Serotype 8 in Tunisia, 2021-2022

Epizootic hemorrhagic disease (EHD) is a non-contagious arthropod-transmitted viral disease and a World Organization for Animal Health (WOAH)-listed disease of domestic and wild ruminants since 2008. EHDV is transmitted among susceptible animals by a few species of midges of genus Culicoides. During the fall of 2021, a large outbreak caused by the epizootic hemorrhagic disease virus (EHDV), identified as serotype 8, was reported in Tunisian dairy and beef farms with Bluetongue virus (BTV)-like clinical signs. The disease was detected later in the south of Italy, in Spain, in Portugal and, more recently, in France, where it caused severe infections in cattle. This was the first evidence of EHDV-8 circulation outside Australia since 1982. In this study, we analyzed the epidemiological situation of the 2021-2022 EHDV outbreaks reported in Tunisia, providing a detailed description of the spatiotemporal evolution of the disease. We attempted to identify the eco-climatic factors associated with infected areas using generalized linear models (GLMs). Our results demonstrated that environmental factors mostly associated with the presence of C. imicola, such as digital elevation model (DEM), slope, normalized difference vegetation index (NDVI), and night-time land surface temperature (NLST)) were by far the most explanatory variables for EHD repartition cases in Tunisia that may have consequences in neighboring countries, both in Africa and Europe through the spread of infected vectors. The risk maps elaborated could be useful for disease control and prevention strategies.

Experimental infection of cattle, sheep, and goats with the newly emerged epizootic hemorrhagic disease virus serotype 8

Epizootic hemorrhagic disease virus serotype 8 (EHDV-8) emerged in Europe for the first time in late 2022. In this study, we investigated the kinetics of EHDV-8 infection in cattle, sheep, and goats.  Following experimental infection with EHDV-8, four out of five calves displayed fever, while another calf exhibited ulcerative and crusty lesions of the muzzle. RNAemia peaked at day 7 post infection in all calves and remained relatively stable till the end of the study, at 78 days post infection. Infectious virus was isolated up to 21 days post infection in one calf. As far as small ruminants are concerned, one sheep experienced fever and two out of five had consistent RNAemia that lasted until the end of the study. Remarkably, infectious virus was evidenced at day 7 post infection in one sheep. In goats, no RNA was observed. All infected animals seroconverted, and a neutralizing immune response was observed in all species, with calves exhibiting a more robust response than sheep and goats. Our study provides insights into the kinetics of EHDV-8 infection and the host immune responses. We also highlight that sheep may also play a role in EHDV-8 epidemiology. Altogether, the data gathered in this study could have important implications for disease control and prevention strategies, providing crucial information to policy makers to mitigate the impact of this viral disease on livestock.

Development and validation of an RT-qPCR for detection and quantitation of emerging epizootic hemorrhagic disease virus serotype 8 RNA from field samples

Epizootic hemorrhagic disease virus (EHDV) is a Culicoides-transmitted virus circulating in multiple serotypes. It has become a concern in the European Union as a novel strain of the serotype 8 (EHDV-8) of clear Northern African origin, has been recently discovered in symptomatic cattle in Italy (islands of Sardinia and Sicily), Spain, and Portugal. Current molecular typing methods targeting the S2 nucleotide sequences -coding for the outermost protein of the virion VP2- are not able to detect the novel emerging EHDV-8 strain as they enrolled the S2 sequence of the unique EHDV-8 reference strain isolated in Australia in 1982. Thus, in this study, we developed and validated a novel typing assay for the detection and quantitation of the novel EHDV-8 RNA from field samples, including blood of ruminants and insects. This molecular tool will certainly support EHDV-8 surveillance and control.

Detection of Enteroviruses and SARS-CoV-2 in Tunisian Wastewater

Monitoring the circulation of enteric viruses in environmental wastewater is a valuable tool for preventing the emergence of waterborne and food-borne diseases in humans. The detection of viruses was performed in five Tunisian wastewater treatment plants, three located in the Grand Tunis City (WWTP 1, WWTP 2, WWTP 3) and two in the Sahel of Tunisia (WWTP 4, WWTP 4), known as very developed and crowded zones, to assess the effectiveness of three biological wastewater treatment procedures namely natural oxidizing lagoons, rotating biodisks procedure, activated sludge procedure, and one tertiary sewage treatment using UV-C254 reactor for this enteric viruses' removal. Thus, 242 sewage samples were collected between June 2019 and May 2020 from different lines of wastewater treatment procedures implemented in the five wastewater treatment plants investigated. SARS-CoV-2 was analyzed using real-time multiplex reverse-transcription polymerase chain reaction (multiplex real-time RT-PCR) and enteroviruses using reverse-transcription polymerase chain reaction (RT-PCR). The enteroviruses detection showed 93% and 73% respective high frequencies only in the two WWTPs of the Grand Tunis (WWTP 1 and WWTP 2). SARS-CoV-2 was detected in 58% of the all wastewater samples collected from the five studied WWTPs with a respective dominance of N gene (47%), S gene (42%), RdRp gene (42%) and at last E gene (20%). These enteroviruses and SARS-CoV-2 detection were revealed in all steps of the wastewater treatment procedures, so poor virological quality is found at the exit of each biological and tertiary step of treatment investigated. For the first time in Tunisia, these results highlighted the enterovirus and SARS-CoV-2 detection with high rates, and the ineffectiveness of the biological and UV-C254 treatment implemented to remove these viruses. The preliminary results of SARS-CoV-2 circulation in Tunisian wastewater confirmed the wide positivity rate underlined by other works worldwide and allowed showing a move towards integrating wastewater as a way for this virus to spread in different areas and environments. So, this last result about SARS-CoV-2 circulation allowed us to caution about the strong probability of diffusion of this hazardous virus through water and sewage; despite its enveloped character and nature, as a labile and sensitive virus in these environments. Thus, establishing a national surveillance strategy is needed to improve the sanitary quality of treated wastewater and prevent public health problems related to these viruses in treated wastewater.

Characterization of Epizootic Hemorrhagic Disease Virus Serotype 8 in Naturally Infected Barbary Deer (Cervus elaphus barbarus) and Culicoides (Diptera: Ceratopogonidae) in Tunisia

Epizootic hemorrhagic disease (EHD) is a Culicoides-borne disease of domestic and wild ruminants caused by EHD virus (EHDV). This virus circulates in multiple serotypes. In late September 2021, a novel strain belonging to EHDV-8 was reported in cattle farms in Central-Western Tunisia, and in the fall of 2022, the same virus was also detected in Italy and Spain. In the present study, we described EHDV-8 occurrence in deer and, a preliminary identification of the potential Culicoides species responsible for virus transmission in selected areas of Tunisia. EHDV-8 was identified in deer carcasses found in 2021 and 2022 in the national reserve of El Feidja, Jendouba, Northwestern Tunisia, and isolated on cell culture. Instead, insect vectors were collected in October 2021 only in the areas surrounding the city of Tozeur (Southern Tunisia) where EHDV-8 cases in cattle were confirmed. Morphological identification showed that 95% of them belonged to the Culicoides kingi and Culicoides oxystoma species and both species tested positive for EHDV-8 RNA. C. imicola was not detected in this collection and EHDV-8 RNA was not evidenced in vector pools collected in 2020, prior to official EHDV-8 emergence. EHDV whole genome sequences were also obtained directly from infected biological samples of deer and positive vectors. EHDV-8 sequences obtained from deer and vectors share a nucleotide identity ranging from 99.42 to 100% and amino acid identity from 99.18 to 100% across all genome segments with the EHDV-8/17 TUN2021 reference sequence.

Epizootic Hemorrhagic Disease Virus Serotype 8, Italy, 2022

We describe the detection of epizootic hemorrhagic disease virus (EHDV) serotype 8 in cattle farms in Sardinia and Sicily in October-November 2022. The virus has a direct origin in North Africa; its genome is identical (>99.9% nucleotide sequence identity) to EHDV serotype 8 strains detected in Tunisia in 2021.

Epizootic Haemorrhagic Disease Virus Serotype 8 in Tunisia, 2021

Epizootic haemorrhagic disease (EHD) is a Culicoides-borne viral disease caused by the epizootic haemorrhagic disease virus (EHDV) associated with clinical manifestations in domestic and wild ruminants, primarily white-tailed deer (Odocoileus virginianus) and cattle (Bos taurus). In late September 2021, EHDV was reported in cattle farms in central/western Tunisia. It rapidly spread throughout the country with more than 200 confirmed outbreaks. We applied a combination of classical and molecular techniques to characterize the causative virus as a member of the serotype EHDV-8. This is the first evidence of EHDV- 8 circulation since 1982 when the prototype EHDV-8 strain was isolated in Australia. This work highlights the urgent need for vaccines for a range of EHDV serotypes.

Culex pipiens distribution in Tunisia: Identification of suitable areas through Random Forest and MaxEnt approaches

BACKGROUND

Tunisia has experienced several West Nile virus (WNV) outbreaks since 1997. Yet, there is limited information on the spatial distribution of the main WNV mosquito vector Culex pipiens suitability at the national level.

OBJECTIVES

In the present study, our aim was to predict and evaluate the potential and current distribution of Cx. pipiens in Tunisia.

METHODS

To this end, two species distribution models were used, i.e. MaxEnt and Random Forest. Occurrence records for Cx. pipiens were obtained from adult and larvae sampled in Tunisia from 2014 to 2017. Climatic and human factors were used as predictors to model the Cx. pipiens geographical distribution. Mean decrease accuracy and mean decrease Gini indices were calculated to evaluate the importance of the impact of different environmental and human variables on the probability distribution of Cx. pipiens.

RESULTS

Suitable habitats were mainly distributed next to oases, in the north and eastern part of the country. The most important predictor was the population density in both models. The study found out that the governorates of Monastir, Nabeul, Manouba, Ariana, Bizerte, Gabes, Medenine and Kairouan are at highest epidemic risk.

CONCLUSIONS

The potential distribution of Cx. pipiens coincides geographically with the observed distribution of the disease in humans in Tunisia. Our study has the potential for driving control effort in the fight against West Nile vector in Tunisia.

Molecular mechanisms and clonal lineages of colistin-resistant bacteria across the African continent: A scoping review

Colistin (also known as Polymyxin E), a polymyxin antibiotic discovered in the late 1940s, has recently reemerged as a last-line treatment option for multidrug-resistant infections. However, in recent years, colistin-resistant pathogenic bacteria have been increasingly reported worldwide. Accordingly, the presented review was undertaken to identify, integrate and synthesize current information regarding the detection and transmission of colistin-resistant bacteria across the African continent, in addition to elucidating their molecular mechanisms of resistance. PubMed, Google Scholar, and Science Direct were employed for study identification, screening and extraction. Overall, based on the developed literature review protocol and associated inclusion/exclusion criteria, 80 studies published between 2000 and 2021 were included comprising varying bacterial species and hosts. Numerous mechanisms of colistin resistance were reported, including chromosomal mutation(s) and transferable plasmid-mediated colistin resistance (encoded by mcr genes). Perhaps unexpectedly, mcr-variants have exhibited rapid emergence and spread across most African regions. The genetic variant mcr-1 is predominant in humans, animals, and the natural environment, and is primarily carried by IncHI2- type plasmid. The highest numbers of studies reporting the dissemination of colistin-resistant Gram-negative bacteria were conducted in the North African region.

AB0539 DEPRESSION, SELF-ESTEEM AND QUALITY OF LIFE IN SJÖGREN’S SYNDROME

Background

Sjögren’s syndrome (SS) is a connective tissue disease characterized by a triad of fatigue, pain and dryness. SS is a chronic condition with important repercussions on functioning and a source of significant suffering. Therefore, the assessment of depressive symptoms, self-esteem and quality of life (QOL) is important in the clinical and research context.

Objectives

We aimed to describe the clinical picture, depression, QOL and self-esteem of patients followed for SS and to study their association with disease activity.

Methods

This is a descriptive and analytical cross-sectional study including 42 patients with SS diagnosed based on the criteria of the American European Consensus Group of 2002 (AECG). Depression was evaluated by the Beck 13 scale, QOL by the SF-36 and self- esteem by the Rosenberg scale. Disease activity was assessed by EULAR Sjörgen Syndrome Disease Activity Index (ESSDAI).

Results

The average age was 54.5 ±15.67 years and the sex ratio was 0.2. Assessment of disease activity of these patients showed an average activity score of 8.23 ±6.39 with low activity in 16 patients (38.1%), moderate activity in 18 patients (42.9%) and severe activity in 8 patients (19%). The QOL measured by SF-36 was impaired in all areas with averages ranging from 39.76 for physical limit to 66.28 for emotional limit. Depression score evaluated by the Beck scale was 8.42 ±7.05on average with 59.5% of the patients having depression. The self-esteem score evaluated by Rosenberg scale was 32.8 ± 5.7on average. Self-esteem was rated as low to very low in 30.95% of patients.

Disease activity score was correlated to Beck’s depression score (r= 0.545; p= 0.001); and Rosenberg’s self-esteem score (r= -0.51; p= 0.001). Likewise, we found a correlation between the SF-36 score and Beck’s depression score; the SF-36 score and Rosenberg’s self-esteem score (p< 0.05).

Conclusion

As QOL, self esteem and depression were correlated to disease activity, taking into account these aspects in SS can improve the overall management of the disease.

References

[1]Milin M, Cornec D, Chastaing M, Griner V, Berrouiguet S, Nowak E, et al. Sicca symptoms are associated with similar fatigue, anxiety, depression, and quality-of-life impairments in patients with and without primary Sjögren’s syndrome. Joint Bone Spine. déc 2016;83(6):681‑5.

[2]Rajagopalan K, Abetz L, Mertzanis P, Espindle D, Begley C, Chalmers R, et al. Comparing the discriminative validity of two generic and one disease-specific health-related quality of life measures in a sample of patients with dry eye. Value Health J Int Soc Pharmacoeconomics Outcomes Res. avr 2005;8(2):168‑74.

[3]Shen C-C, Yang AC, Kuo BI-T, Tsai S-J. Risk of Psychiatric Disorders Following Primary Sjögren Syndrome: A Nationwide Population-based Retrospective Cohort Study. J Rheumatol. juill 2015;42(7):1203‑8.

[4]Stevenson HA, Jones ME, Rostron JL, Longman LP, Field EA. UK patients with primary Sjögren’s syndrome are at increased risk from clinical depression. Gerodontology. sept 2004;21(3):141‑5.

[5]Kang J-H, Lin H-C. Comorbidities in patients with primary Sjogren’s syndrome: a registry-based case-control study. J Rheumatol. Juin 2010;37(6):1188‑94. Page 88

[6]Cui Y, Li L, Yin R, Zhao Q, Chen S, Zhang Q, et al. Depression in primary Sjögren’s syndrome: a systematic review and meta-analysis. Psychol Health Med. févr 2018;23(2):198‑209.

[7]Bax HI, Vriesendorp TM, Kallenberg CGM, Kalk WWI. Fatigue and immune activity in Sjögren’s syndrome. Ann Rheum Dis. mars 2002;61(3):284.

[8]Cui Y, Xia L, Li L, Zhao Q, Chen S, Gu Z. Anxiety and depression in primary Sjögren’s syndrome: a cross-sectional study. BMC Psychiatry. 16 2018;18(1):131.

Disclosure of Interests

None declared

AB1481 RedOx HOMEOSTASIS AND ANTIOXIDANT RESPONSE DEFENSE IN SKELETAL MUSCLE PERFORMANCE IN THE ELDERLY

Background

Aging is accompanied by a progressive decline in physical activity due to a loss of skeletal muscle mass and strength considered as a geriatric characteristic defined as sarcopenia. This latter may be associated with joint damage, all of which may predispose older people to the risk of falls. Few evidences suggest that oxidative stress plays a key role in the pathophysiology of sarcopenia.

Objectives

The aim of this study was to clarify the relationship between sarcopenia and oxidative stress. To this end, measurements of antioxidant enzyme activities as well as levels of lipid oxidation products were performed on plasma and/or red blood cells.

Methods

All the participants (age ≥ 65) were classified into two groups according to the SARC-F score: non-sarcopenic patients (SARC-F <4; n=50) and sarcopenic (SARC-F ≥4; n=50). Redox biomarkers: antioxidant enzymes (erythrocyte superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPx) activities) as well as, lipid peroxidation products (plasma malondialdehyde (MDA), and conjugated dienes (CD) levels), were measured using spectrophotometric methods.

Results

SOD levels were significantly higher in the group of sarcopenic patients than in non- sarcopenic subjects (3.20 ± 1.00 U/mg Hb vs. 2.41 ± 0.88 U/mg Hb, respectively, p= 0.007). Similarly, catalase levels were significantly higher in sarcopenic patients compared with non sarcopenicsubjects (0.13 ± 0.04 U/mg Hb vs. 0.11 ± 0.03 U/mg Hb, respectively, p= 0.008). However, no significant differences in GPx levels were detected (p= 0.254). An accumulation of lipid oxidation biomarkers MDA (17.14 ± 3.13 nmol/mg protein vs. 10.39 ± 2.60 nmol/mg protein) and CD (0.24 ± 0.09 nmol/mg protein vs. 0.17 ± 0.06 nmol/mg protein) was observed in the plasma of sarcopenic patients compared with non- sarcopenic subjects(p< 0. 001 and p= 0.003, respectively).

Conclusion

Sarcopenia is associated with oxidative stress as shown by increased levels of antioxidant enzyme activities (SOD, GPx) and lipid peroxidation products (MDA, CD).

References

[1]Liguori I, et al Clin Interv Aging. 2018;13:757-772

[2]Ghzaiel I et al, Antioxidants2021, 10, 1772. https://doi.org/10.3390/antiox10111772

Disclosure of Interests

None declared

AB0607 Vascular involvement in Behçet’s Disease

Background

Behçet’s disease (BD) is a multisystemic inflammatory vasculitis, which can affect all types and sizes of blood vessels. It diagnosis is based on a multitude of classification criteria, which include vascular complications associated to this vasculitis.

Objectives

In this study, we reported the main characteristics of vascular involvement in patients with BD.

Methods

In total, 243 patients with BD were, retrospectively, collected in the Internal Medicine Department over 18 years.

Results

Vascular involvement was present in 72 patients (29.6%), whose 57 men and 15 women. The mean age was 32.9 years (range: 5-56 years). It revealed the disease in 26.3% of cases. Venous involvement was predominant, found in 68% of patients. Venous thrombosis interested: the upper limbs (51%), the lower limbs (38.7%), the pulmonary veins (18.3%), the inferior vena cava (12.2%) and the cerebral veins in 1 patient. Superficial venous thrombosis was present in 20.8% of cases. Arterial involvement was present in 11.1% of patients. It included pulmonary artery aneurysms in 8 cases and occlusion of the central retinal artery in one patient. The other associated systemic manifestations were: skin and mucous membrane disorders (100%), joint involvement (34.7%), ocular (29.2%), neurological (27.8%) and cardiac involvement in 7 patients. Treatment was based on long term curative anticoagulation (70%), corticosteroid therapy (50%) and immunosuppressive treatment in 21% of cases. Embolization was performed in two patients with good results.

Conclusion

Our study illustrates the frequency and the polymorphism of vascular involvement in BD.

References

[1]Kechrid Laouani C; Rev Med Int 2021; 42: A360

Disclosure of Interests

None declared

AB1448 DEEP VENOUS THROMBOSIS IN YOUNG ADULTS: INCIDENCE AND RISK FACTORS

Background

After a first venous thromboembolic (VTE) episode, recurrence is frequent and associated with significant morbidity and mortality.

Objectives

Our aim is to identify the risk factors for recurrent VTE in young subjects and to assess the risk-benefit ratio of continuing long-term anticoagulant treatment.

Methods

We carried out a retrospective study including 100 patients with deep vein thrombosis (DVT) admitted to the Internal Medicine Department at Fattouma Bourguiba University Hospital in Monastir between 2011 and 2020.

Results

In our study, the gender ratio was 1.17. The mean age was 34.49 years ± 9.19. Lower extremity deep venous thrombosis (LEDVT) was the most common location (90%). Pulmonary embolism (PE) was found in 8% of cases. The most frequent risk factors were obesity: BMI>30 (40%), bed rest (20%), personal history of DVT (18%), smoking (16%), recent surgery dating less than one month (14%), and recent trauma (12%). The etiological assessment had concluded to inherited thrombophilia in 41 cases: protein S deficiency (23%), protein C deficiency (8%), activated protein C resistance (8%), and antithrombin III deficiency (2%); acquired thrombophilia in 28 cases: hyperhomocysteinemia (HH) in 19 cases and antiphospholipid syndrome (APLS) in 9 cases; Behçet’s disease in 10 cases and systemic lupus erythematosus in 5 cases. No cases of neoplasia were detected. The treatment was based on low molecular weight heparin (LMWH), relayed by vitamin k antagonists (VKAs), and physical therapy (graduated compression stockings and early mobilization). Duration of the treatment of DVT in the young adult depends on the nature and extent of the thrombosis, the underlying risk factors, and etiologies. Among the 100 hospitalized patients, recurrent DVT was detected in 20% of cases: 17% of patients reported a history of DVT with a mean number of previous episodes of 2, and only 3% developed DVT during their follow-up. The mean time to recurrence was three years. Recurrence was located on the same side in most cases (70%). In our study, only Behçet’s disease was associated with an increased risk of DVT recurrence (p: 0.015, OR: 5.46, CI [1.38-21.56]). Gender, age, venous insufficiency, and bed rest had no significant influence on the risk of recurrence (p>0.05).

Conclusion

Young adults should be assessed for acquired and also genetic factors, which would suggest extending the duration of anticoagulant therapy in high-risk patients, reducing the incidence of post-thrombotic syndrome and VTE recurrence. Further studies are needed to evaluate the association of Behçet’s disease with DVT recurrence.

Disclosure of Interests

None declared

Hiding in plain sight - Wildlife as a neglected reservoir and pathway for the spread of antimicrobial resistance: A narrative review

Antimicrobial resistance represents a global health problem, with infections due to pathogenic antimicrobial resistant bacteria (ARB) predicted to be the most frequent cause of human mortality by 2050. The phenomenon of antimicrobial resistance has spread to and across all ecological niches, and particularly in livestock used for food production with antimicrobials consumed in high volumes. Similarly, hospitals and other healthcare facilities are recognized as significant “hotspots” of ARB and antimicrobial resistance genes (ARGs); however, over the past decade, new and previously overlooked ecological niches are emerging as hidden reservoirs of ARB/ARGs. Increasingly extensive and intensive industrial activities, degradation of natural environments, burgeoning food requirements, urbanization, and global climatic change have all dramatically affected the evolution and proliferation of ARB/ARGs, which now stand at extremely concerning ecological levels. While antimicrobial resistant bacteria and genes as they originate and emanate from livestock and human hosts have been extensively studied over the past 30 years, numerous ecological niches have received considerably less attention. In the current descriptive review, the authors have sought to highlight the importance of wildlife as sources/reservoirs, pathways and receptors of ARB/ARGs in the environment, thus paving the way for future primary research in these areas.

High rates of antibiotic resistance and biofilm production in Escherichia coli isolates from food products of animal and vegetable origins in Tunisia: a real threat to human health

The aim of this study was to compare the antibiotic susceptibility of eighty Escherichia coli isolates from vegetables and food products of animal origin in Tunisia, and to study their genes encoding antibiotic resistance and in vitro biofilm forming capacity. Antimicrobial susceptibilities were determined, as well as PCR investigation of genes associated with antibiotic resistance. Biofilm formation was tested using four different methods: the microtiter plate-, MTT-staining-, XTT-staining-, and the Congo Red Agar assays. High antibiotic resistance rates were observed for amoxicillin (68.7%), amoxicillin/clavulanic acid (73.7%), gentamicin (68.7%), kanamycin (66.2%), nalidixic acid (36.2%), streptomycin (68.7%) and tetracycline (35%). The majority of isolates was multidrug resistant and biofilm producer. MTT testing showed that vegetables isolates were significantly higher biofilm producers compared to foods of animal origins. This study showed that E. coli isolates from food products were reservoirs of genes encoding antibiotic-resistance and have a high propensity to produce biofilm.

Serological evidence of Rift Valley fever in domestic ruminants in Tunisia underlines the need for effective surveillance

Background:

Rift Valley fever (RVF) is an infectious zoonotic disease infecting, mainly, domestic ruminants and causing significant economic and public health problems. RVF is a vector-borne disease transmitted by mosquitoes.

Aim:

In this work, we tried to seek any RVF virus circulation in Tunisia.

Methods:

Thus, we investigated 1,723 sera from different parts of Tunisia, collected in 2009 and 2013–2015 from sheep, goats, cattle, and dromedaries. All sera were assessed using enzyme-linked immunosorbent assay techniques.

Results:

Eighty-seven sera were detected positive and 11 doubtful. All of them were investigated by the virus-neutralization technique (VNT), which confirmed the positivity of three sera.

Conclusion:

This is the first case of RVF seropositive confirmed by the VNT in Tunisian ruminants. Such a result was expected considering the climate, entomology, and geographic location of the country. Further investigations must enhance our findings to understand the RVF epidemiologic situation better and implement risk-based surveillance programs and effective control strategies.

Inactivation of Hepatovirus A in wastewater by 254 nm ultraviolet-C irradiation

Hepatovirus A is known as a waterborne and foodborne virus that can be transmitted from one person to another through contaminated water and raw food. Therefore, it is necessary to survey the circulation of this type of enteric virus in the wastewater to prevent prospective outbreaks. Wastewater samples collected from WWTP El Menzeh I and Charguia I have been the subject for physicochemical, bacteriological (MPN) and virological analyses. Hepatovirus A (HAV) detection was carried out using the standard reverse transcription-polymerase chain reaction (RT-PCR). Hepatovirus A was detected respectively in 62% (63/102) and 66% (92/140) of the collected wastewater samples at El Menzeh I and Charguia I WWTPs. The treated effluent by natural oxidizing lagoon procedure was characterized by a poor physical-chemical and virological qualities but with excellent bacteriological quality. Consequently, this effluent is not suitable to be recycled and reused in agriculture or even dismissed in the environment. The treated sewage by activated sludge and rotating biodisk procedures turned out to be of a very good physical-chemical quality but with a poor bacteriological and virological quality. After tertiary UV-C₂₅₄ nm irradiation, the faecal indicator bacteria concentration was mostly reduced and removed. These findings confirmed the need for improvement and upgrade of the treatment processes used in these two studied sewage purification plants and the necessity of implementation and establishment of a proper national virological standard to control the circulation rates of enteric viruses in Tunisian municipal wastewater.

Spatial distribution and habitat selection of culicoides imicola: The potential vector of bluetongue virus in Tunisia

The increasing threat of vector-borne diseases (VBDs) represents a great challenge to those who manage public and animal health. Determining the spatial distribution of arthropod vector species is an essential step in studying the risk of transmission of a vector-borne pathogen (VBP) and in estimating risk levels of VBD. Risk maps allow better targeting surveillance and help in designing control measures. We aimed to study the geographical distribution of Culicoides imicola, the main competent vector of Bluetongue virus (BTV) in sheep in Tunisia. Fifty-three records covering the whole distribution range of C.imicola in Tunisia were obtained during a 2-year field entomological survey (August 2017 – January 2018 and August 2018 – January 2019). The ecological niche of C. imicola is described using ecological-niche factor analysis (ENFA) and Mahalanobis distances factor analysis (MADIFA). An environmental suitability map (ESM) was developed by MaxEnt software to map the optimal habitat under the current climate background. The MaxEnt model was highly accurate with a statistically significant area under curve (AUC) value of 0.941. The location of the potential distribution of C. imicola is predicted in specified regions of Tunisia. Our findings can be applied in various ways such as surveillance and control program of BTV in Tunisia.

Attenuation of 7-ketocholesterol- and 7β-hydroxycholesterol-induced oxiapoptophagy by nutrients, synthetic molecules and oils: Potential for the prevention of age-related diseases

Age-related diseases for which there are no effective treatments include cardiovascular diseases; neurodegenerative diseases such as Alzheimer's disease; eye disorders such as cataract and age-related macular degeneration; and, more recently, Severe Acute Respiratory Syndrome (SARS-CoV-2). These diseases are associated with plasma and/or tissue increases in cholesterol derivatives mainly formed by auto-oxidation: 7-ketocholesterol, also known as 7-oxo-cholesterol, and 7β-hydroxycholesterol. The formation of these oxysterols can be considered as a consequence of mitochondrial and peroxisomal dysfunction, leading to increased in oxidative stress, which is accentuated with age. 7-ketocholesterol and 7β-hydroxycholesterol cause a specific form of cytotoxic activity defined as oxiapoptophagy, including oxidative stress and induction of death by apoptosis associated with autophagic criteria. Oxiaptophagy is associated with organelle dysfunction and in particular with mitochondrial and peroxisomal alterations involved in the induction of cell death and in the rupture of redox balance. As the criteria characterizing 7-ketocholesterol- and 7β-hydroxycholesterol-induced cytotoxicity are often simultaneously observed in major age-related diseases (cardiovascular diseases, age-related macular degeneration, Alzheimer's disease) the involvement of these oxysterols in the pathophysiology of the latter seems increasingly likely. It is therefore important to better understand the signalling pathways associated with the toxicity of 7-ketocholesterol and 7β-hydroxycholesterol in order to identify pharmacological targets, nutrients and synthetic molecules attenuating or inhibiting the cytotoxic activities of these oxysterols. Numerous natural cytoprotective compounds have been identified: vitamins, fatty acids, polyphenols, terpenes, vegetal pigments, antioxidants, mixtures of compounds (oils, plant extracts) and bacterial enzymes. However, few synthetic molecules are able to prevent 7-ketocholesterol- and/or 7β-hydroxycholesterol-induced cytotoxicity: dimethyl fumarate, monomethyl fumarate, the tyrosine kinase inhibitor AG126, memantine, simvastatine, Trolox, dimethylsufoxide, mangafodipir and mitochondrial permeability transition pore (MPTP) inhibitors. The effectiveness of these compounds, several of which are already in use in humans, makes it possible to consider using them for the treatment of certain age-related diseases associated with increased plasma and/or tissue levels of 7-ketocholesterol and/or 7β-hydroxycholesterol.

AB0346 RHUPUS SYNDROME: CLINICAL ANALYSIS OF 21 PATIENTS

Background:

Rhupus syndrome is a clinical condition characterized by a combination of the clinical and immunologic features of rheumatoid arthritis (RA) and systemic lupus erythematosus (SLE) (1). However, this definition did not establish whether Rhupus syndrome is a distinct clinical entity or is an overlap between RA and SLE. To date, fewer than 200 cases of Rhupus have been reported (1).

Objectives:

Our purpose was to analyze the clinical and serological characteristics of patients with Rhupus and compare them with patients with SLE.

Methods:

We undertook a retrospective study covering 10 years (2009 to 2019) of experience in our University Hospital: Department of Internal Medicine and department of Rheumatology. 238 patients hospitalized were evaluated during this period. The clinical and laboratory parameters of 21 patients with Rhupus syndrome were compared with those of 217 SLE without RA patients

Results:

Twenty one patients were included (all fulfilled ACR criteria for SLE as well as for RA).They were 19 female and 2 male. The mean age of patients at the disease onset was 43.5 years. Among these, 9 patients (42.8%) were diagnosed with RA at the onset of disease and then developed SLE over an average period of 6.2 years. Six patients (28.5%) had a diagnosis of SLE prior to the RA diagnosis with an interval of 8.6 years between diagnoses. Six patients (28.5%) were diagnosed with RA and SLE concomitantly. Patients with Rhupus experienced more often arthritis, joint swelling, morning stiffness and joint erosions then patients with SLE alone (p<0.001). Comparison of extra-articular manifestations showed that, renal involvement was less often in patients with Rhupus when compared to patients with SLE-alone. There were no significant differences in the prevalence of malar rash, serositis, neurological and hematological features between the Rhupus and SLE-alone groups. Rheumatoid factor and anticyclic citrullinated peptide (CCP) antibody were significantly more prevalent in the Rhupus group than in the control group. The incidences of increased erythrocyte sediment rate (ESR) and C-reactive protein (CRP) were also significantly higher in Rhupus patients. (Table 1)

Table 1.

Comparison of clinical and biological features between Rhupus Syndrome (Rhupus Group) and SLE-alone patients (Control Group).

Rhupus GroupN=21 (%)Control GroupN=217 (%)pMalar rash12 (57.1)120 (55.3)0.87serositis6 (28.5)47 (21.7)0.46Lupus nephritis4 (19)56 (25.8)0.49Hemolytic anemia1 (4.7)8 (3.6)1Leucopenia8 (38)90 (41.4)0.15Thrombopenia4 (19)27 (12.4)1Polyarthritis21 (100)54 (24.8)<0.001Erosion of joint21 (100)0<0.001Increased ESR20 (95.2)155 (71.4)0.019Increased CRP18 (85.7)88 (40.5)<0.001Anti-DNA antibodies16 (76.1)134 (61.7)0.61Anti-Sm antibodies6 (28.5)63 (29)0.57Rhumatoide Factor12 (57.1)52 (23.9)0.04Anti-CCP antibody6 (28.5)14 (6.5)0.027

CRP: C-reactive protein, ESR: erythrocyte sediment rate, Anti-CCP: anticyclic citrullinated peptide antibody.

Conclusion:

Patients sharing features of both RA and SLE have been observed infrequently. In fact, the incidence of Rhupus syndrome in SLE patients is estimated at 1.3% (2). In our study, this incidence was 8.8%. The findings of our study are consistent with those of most studies with respect to the frequencies arthritis, lupus related features, and serological disorders (2,3).

References:

[1]Rubini E, Foddai SG, Radin M, Cecchi I, Rossi D, Sciascia S, et al. Ab1177 How to Define Rhupus Syndrome: Systematic Review of the Current Literature. Ann Rheum Dis. 2019 Jun 1;78(Suppl 2):2049–50.

[2]Li J, Wu H, Huang X, Xu D, Zheng W, Zhao Y, et al. Clinical Analysis of 56 Patients with Rhupus Syndrome: Manifestations and Comparisons with Systemic Lupus Erythematosus. Medicine(Baltimore). 2014; 93(10): 958-63.

[3]Liu T, Li G, Mu R, Ye H, Li W, Li Z. Clinical and laboratory profiles of rhupus syndrome in a Chinese population: a single-centre study of 51 patients. Lupus. 2014;23(9):958–63.

Disclosure of Interests:

None declared

AB0273 HYPERSENSIVITY REACTIONS TO NON STEROID ANTI INFLAMMATORY DRUGS: A BOUT 87 CASES

Background:

Non-steroidal anti-inflammatory drugs (NSAIDs) are one of the leading causes of hypersensitivity reactions to drugs. The pathogenesis may be immunological mechanisms (allergic reactions) or non specific immunological reactions often incriminated in cross reactivity independently of chemical structure of these molecules. Understanding of the underlying mechanism is necessary for prevention and choice of safe alternatives [1, 2].

Objectives:

Analyze all cases of non-steroidal anti-inflammatory drugs cutaneous eruption reported to sfax pharmacovigilance service since January 2015 to December 2020 and evaluate the possibility of cross-reactions between different molecules in this class.

Methods:

We conducted a retrospective study of all cases reported to sfax pharmacovigilance department. An enquiry of pharmacovigilance was performed in patients who presented side effects to AINS. The imputability study was carried out by the French method of Imputability. Medical history specifies if there is a re-administration to assess tolerance and cross-reactivity.

Results:

Our study included 87 patients whose average age was 45, 8 years. The sex ratio (F/M) was 1.18. lysine salicylate acetyl is the most incriminated (31%), then mefenamic acid (19.5%), diclofenac (19.5 %), ketoprofen in (9.2%), piroxicam in (6.9 %), ibuprofen in (5.4%), celocoxib in (3.4%), tiaprofenic acid in (1.1%) and naproxen in 1.1% of cases. The most common skin injury was urticaria in 29 cases (33.3%). Fixed drug eruption was observed in 17 cases. Maculopapular rash was observed in 19 cases, anaphylaxis in 5 cases and 4 cases of photosensitivity were observed. In our study we found cross-reactivity between (NSAIDs) in 8 patients.

Conclusion:

The diagnostic approach is often based on the controlled administration of the drug to assess tolerance and to identify safe alternatives. In cases of intolerance to COX 1 inhibitors, cross-reactions to selective cox 2 inhibitors are very rare [3].

References:

[1]Inmaculada Dona, Maria Salas, James R Perkins and al. Hypersensitivity Reactions to Non-Steroidal Anti-Inflammatory Drugs. Curr Pharm Des 2016; 22(45):6784-6802.

[2]Flavia Angeletti, Franziska Meier, Nadja Zöller, Markus Meissner, Roland Kaufmann, Eva Maria Valesky. Hypersensitivity reactions to non-steroidal anti-inflammatory drugs (NSAIDs) - a retrospective study. J Dtsch Dermatol Ges 2020 Dec; 18(12):1405-1414.

[3]N Blanca-López, J A Cornejo-García, M C Plaza-Serón, and al. Hypersensitivity to Nonsteroidal Anti-inflammatory Drugs in Children and Adolescents: Cross-Intolerance Reactions. J Investig Allergol Clin Immunol 2015; 25(4):259-69.

Disclosure of Interests:

None declared

AB0059 STUDY OF THE ANTI-INFLAMMATORY EFFECT OF CINNAMOMUM VERUM IN RATS

Background:

Inflammatory response is a common physiological response that protects the host of many harmful stimuli such as toxins, local injuries and pathogens. Today, non-steroidal anti-inflammatory drugs are the most commonly prescribed for the treatment of many inflammatory treatments. However, long term administration of these NSAIDs causes many adverse effects, including gastrointestinal ulcers and bleeding and kidney damage. Therefore, the need for new anti-inflammatory drugs with fewer side effects is required.

Objectives:

The aim of our study was to evaluate the anti-inflammatory activity of Cinnamomum verum (C. Verum) on rats while testing the dose effect and the typical effect of the solvent.

Methods:

The edema was induced by injection of carrageenan solution (CARR) in paw of rats according to the method of Winter et al, 1963. The measurements of volumes of right hind paw of each rat were taken before induction of edema and each 1 h, 2 h, 3 h, 4 h and 5 h after the injection of carrageenan. 7 groups of 6 rats received, one hour before the injection of the carrageenan, different treatment: G1= witness, G2=CARR + saline solution, G3= CARR+ Acetylsalicylic acid, G4= CARR + C. verum- MeOH 100, G5= CARR + C. verum- MeOH 300, G6= CARR + CARR + C. verum- EtOH 100 and G7= CARR + C.verum- EtOH 300.

Results:

For this test, the volume of edema increases with time, this increase is greater in the group treated with saline solution than with the extracts of C.Verum and with Acetylsalicylic acid. The extracts of C. Verum administered intraperitoneally one hour before the injection of the carrageenan, reduced the edema in the third hour after.

Conclusion:

The interesting anti-inflammatory activity of Cinnamomum verum recorded in this work may at least in part support its popular use in traditional medicine [1, 2].

References:

[1]Mirza Muhammad Fahd Qadir, Attya Bhatti, Muhammad Usman Ashraf, Mansur Abdullah Sandhu, Sidrah Anjum, Peter John. Immunomodulatory and therapeutic role of Cinnamomum verum extracts in collagen-induced arthritic BALB/c mice. Inflammopharmacology 2018 Feb;26(1):157-170.

[2]Heping Cao, Joseph F Urban Jr, Richard A Anderson. Cinnamon polyphenol extract affects immune responses by regulating anti- and proinflammatory and glucose transporter gene expression in mouse macrophages. J Nutr 2008 May;138(5):833-40.

Disclosure of Interests:

None declared

AB0395 RENAL INVOLVEMENT IN HENOCH-SCHÖNLEIN PURPURA

Background:

Henoch-Schönlein purpura (HSP), also known as rheumatic purpura, is an immune complex vasculitis affecting small vessels with dominant IgA deposits. Clinical manifestations mainly involve cutaneous purpura, arthralgias and/or arthritis, acute enteritis and glomerulonephritis. HSP is more common among children than adults. Kidney damage is the principal prognostic determinant in HSP. The aim of this study is to evaluate the renal manifestations of HSP.

Objectives:

The aim of this study is to evaluate the renal manifestations of HSP.

Methods:

This was a retrospective study of 35 patients with diagnosed HSA, who were admitted between the time period may 2008 and november 2018. All of these patients met the American College of Rheumatology classification criteria for a diagnosis of HSP. Renal involvement was defined as the presence of proteinuria or hematuria.

Results:

The study group consisted of 35 patients, 20 women (57%) and 15 men (43%). The mean age was 48.8± 18.7 years. The incidence rates of skin, joint, gastrointestinal and central nervous system involvement were 91.4, 77.1, 54.2 and 2.8%, respectively. Elevated serum IgA levels occurred in 5.7 %. Six patients (17.1%) were given corticosteroids during the first 3 months of their HSP, which were indicated for severe gastrointestinal (n=5) or renal involvement (n=1). Eighteen of the thirty five patients (51.42%) had renal involvement. There were 12 women and six men. All patients had proteinuria (100%). Hematuria has been identified in 11 patients (61.1%) and renal insufficiency in 4 patients (22.2%). The renal involvement was mainly detected in the first month. Renal biopsy was affected in four patients (22.2%). An endocapillary glomerulonephritis was found in 3 patients and an extra capillary necrotizing glomerulonephritis in one patient. The immunofluorescence showed the presence of IgA deposits in 4 patients.

Conclusion:

Renal involvement dominates the prognosis for the disease. The most common clinical expression is the association of microscopic hematuria with proteinuria.

Disclosure of Interests:

None declared

Genetic characterization of extended-spectrum β-lactamase-producing Enterobacteriaceae from a biological industrial wastewater treatment plant in Tunisia with detection of the colistin-resistance mcr-1 gene

This study evaluated the occurrence of extended-spectrum β-lactamases (ESBL) and associated resistance genes, integrons, and plasmid types, as well as the genetic relatedness of enterobacterial isolates in the wastewater treatment plant (WWTP) of La Charguia, Tunis City (Tunisia). A total of 100 water samples were collected at different points of the sewage treatment process during 2017-2019. Antimicrobial susceptibility was conducted by the disc-diffusion method. blaCTX-M, blaTEM and blaSHV genes as well as those encoding non-β-lactam resistance, the plasmid types, occurrence of class1 integrons and phylogenetic groups of Escherichia coli isolates were determined by PCR/sequencing. Genomic relatedness was determined by multi-locus sequence typing (MLST) for selected isolates. In total, 57 ESBL-producer isolates were recovered (47 E. coli, eight Klebsiella pneumoniae, 1 of the Citrobacter freundii complex and 1 of the Enterobacter cloacae complex). The CTX-M-15 enzyme was the most frequently detected ESBL, followed by CTX-M-27, CTX-M-55 and SHV-12. One E. coli isolate harboured the mcr-1 gene. The following phylogroups/sequence types (STs) were identified among ESBL-producing E. coli isolates: B2/ST131 (subclade-C1), A/ST3221, A/ST8900, D/ST69, D/ST2142, D/ST38, B1/ST2460 and B1/ST6448. High numbers of isolates harboured the class 1 integrons with various gene cassette arrays as well as IncP-1 and IncFIB plasmids. Our findings confirm the importance of WWTPs as hotspot collectors of ESBL-producing Enterobacteriaceae with a high likelihood of spread to human and natural environments.

Rabies in Tunisia: A spatio-temporal analysis in the region of CapBon-Nabeul

Human rabies is a significant public health concern in Tunisia. However, the spatiotemporal spread pattern of rabies in dogs, the major reservoir and vector, and its determinants are poorly understood. We collected geographic locations and timeline of reported animal rabies cases in the region of CapBon (study area), for the years 2015-2019 and integrated them in Geographical Information System (GIS) approach to explore the spatio-temporal pattern of dog rabies. The results show that roads and irrigated areas can act as ecological corridors to viral spread. Our study showed that there was a significant seasonal variation in the number of cases of rabies recorded, with a strong peak in spring and lower peak in winter and summer. These findings may play a role in updating and directing public health policy, as well as providing opportunities for authorities to explore control options in time and space. A better knowledge of the ecology and dog population dynamics is still necessary and important to achieve an effective rabies control.

Phytochemical profile and antioxidant properties of leaves extracts from Posidonia oceanica (L.) Delile and their allelopathic potential on terrestrial plant species

Dichloromethane, chloroform, ethyl acetate and ethanol extracts obtained from Posidonia oceanica (L.) leaves, were examined in order to determine their total phenolic, flavonoid, flavonol, anthocyanin and condensed tannins contents as well as their antioxidant and allelopathic activities. The qualitative phytochemical analysis of crude extracts confirmed the presence of coumarins in dichloromethane, chloroform and ethyl acetate extracts. The antioxidant activity estimated using the DPPH assay was significantly more pronounced for the ethyl acetate extract (IC50 = 1.19±0.018 mg/mL) than that of the other extracts. The allelopathic effect against the seeds of Carum carvi (L.) and Foeniculum vulgare (Mill.) indicated that, depending on concentration, the extracts from the leaves of P. oceanic (L.) inhibited or stimulated at different concentrations the germination, shoot and root elongation of seedlings growth. The results of this study suggest that P. oceanica (L.) extracts could be useful as a natural source of health-promoting effects and herbicides.                     KEY WORDS: Posidonia oceanic (L.), Phytochemical profile, Phenolic compounds, Antioxidant activity, Carum carvi (L.), Foeniculum vulgare (Mill)   Bull. Chem. Soc. Ethiop. 2020, 34(3), 437-447. DOI: https://dx.doi.org/10.4314/bcse.v34i3.1

Genetic characterization of ESBL-producing Escherichia coli and Klebsiella pneumoniae isolated from wastewater and river water in Tunisia: predominance of CTX-M-15 and high genetic diversity

Aquatic environments are crucial hotspots for the dissemination of antibiotic resistant microorganisms and resistance genes. Thus, the purpose of this study was to investigate the occurrence and the genetic characterization of cefotaxime-resistant (CTX^R) Enterobacteriaceae at a Tunisian semi-industrial pilot plant with biological treatment (WWPP) and its receiving river (Rouriche River, downstream from WWPP) located in Tunis City, during 2017-2018. We collected 105 and 15 water samples from the WWPP and the Rouriche River, respectively. Samples were screened to recover ESBL-producing Enterobacteriaceae (ESBL-E) and isolates were characterized for phenotype/genotype of antimicrobial resistance, integrons, plasmid types and molecular typing (multilocus sequence typing, MLST). Among 120 water samples, 33 and 4 contained ESBL-producing E. coli and K. pneumoniae isolates, respectively. Most isolates were multidrug resistant and produced CTX-M-15 (28 isolates), CTX-M-1 (4 isolates), CTX-M-55 (2 isolates), CTX-M-27 (one isolate), SHV-12 (one isolate) and VEB beta-lactamases (one isolate). All K. pneumoniae were CTX-M-15-positive. Four colistin-resistant isolates were found (MIC 4-8 μg/ml), but they were negative for the mcr genes tested. Class 1 integrons were detected in 21/25 trimethoprim/sulfamethoxazole-resistant isolates, and nine of them carried the gene cassette arrays: aadA2 + dfrA12 (n = 4), aadA1 + dfrA15 (n = 2), aadA5 + dfrA17 (n = 2) and aadA1/2 (n = 1). The IncP and IncFIB plasmids were found in 30 and 16 isolates, respectively. Genetic lineages detected were as follows: E. coli (ST48-ST10 Cplx, ST2499, ST906, ST2973 and ST2142); K. pneumoniae: (ST1540 and ST661). Our findings show a high rate of CTX-M-15 and high genetic diversity of ESBL-E isolates from WWPP and receiving river water.

The Effectiveness of Activated Sludge Procedure and UV-C254 in Norovirus Inactivation in a Tunisian Industrial Wastewater Treatment Plant

The molecular detection of Norovirus GI and Norovirus GII in the Tunisian industrial wastewater treatment plant of Charguia I was conducted to test the effectiveness of secondary biological treatment using the activated sludge procedure and the UV-C₂₅₄ tertiary treatment radiation using a UV disinfection prototype to upgrade the quality of the purified wastewater. A total of 140 sewage samples were collected from the two lines of sewage treatment procedures. Norovirus GI and Norovirus GII have been found and quantified using Real-Time Reverse Transcription Polymerase Chain Reaction (qRT-PCR) in 66.4 and 86.4% of the collected wastewater samples. The Norovirus GI and GII mean concentration values got in the treated effluents showed a significant decrease of Norovirus viral content rates detected from upstream to downstream of activated sludge procedures and at the output of UV-C₂₅₄ treatment. These findings characterise and denote for the first time the effectiveness of biological and UV-C254 treatment for Norovirus GI and Norovirus GII removal in Tunis City, northern Tunisia. Also, these data underlined the fact that purified sewage makes up a route of gastroenteritis virus transmission and a cause of viral gastroenteritis associated with water-borne and food-borne outbreaks.

Detection of enzootic circulation of a new strain of West Nile virus lineage 1 in sentinel chickens in the north of Tunisia

Tunisia has experienced various West Nile disease outbreaks. Notwithstanding the serological and molecular confirmations in humans, horses and birds, the human surveillance system can still be improved. Three sentinel chicken flocks were placed in different Tunisian endemic regions and followed up from September 2016 to January 2017. A total of 422 sera from Sejnene (north of Tunisia), 392 from Moknine (east coast of Tunisia) and 386 from Tozeur (south of Tunisia) were tested for West Nile-specific antibodies and viral RNA. The WNV elisa positive rate in sentinel chickens in Sejnene was 10.7% (95% CI: 5.08-21.52). No positive samples were detected in Moknine. In Tozeur, the overall serological elisa positive rate during the study period was 9.8% (95% CI:4.35-21.03). West Nile virus nucleic acid was detected in two chickens in Sejnene.Phylogenetic analysis of one of the detected partial NS3 gene sequences showed that recent Tunisian WNV strain belong to WNV lineage 1 and is closely related to Italian strains detected in mosquitoes in 2016 and in a sparrow hawk in 2017. This report showed the circulation, first molecular detection and sequencing of WNV lineage 1 in chickens in the north of Tunisia and highlights the use of poultry as a surveillance tool to detect WNV transmission in a peri-domestic area.

The performance of biological and tertiary wastewater treatment procedures for rotaviruses A removal

Enteric viruses, generally found in sewage, are recognized as the main cause of waterborne and foodborne public health outbreaks. Among leading enteric viruses, the Rotavirus A (RVA) detection in wastewater appeared to be a novel approach to monitor the emergence of these viruses in some countries where the viral gastroenteritis surveillance is almost absent such as in Tunisia. The RVA detection and quantification in an industrial sewage purification plant of Charguia I (Tunis, Tunisia) were achieved to evaluate the performance of activated sludge procedures coupled to a macrofiltration monolamp ultraviolet irradiation type C (UV-C₂₅₄) disinfection reactor. This UV-C₂₅₄ system was preceded by a fiberglass cartridge filter system with an average porosity of 45 μm to clarify the water and thus increase its UV transmittance. A total of 140 composite sewage samples was collected from this line of treatment and analyzed for RVA detection. The detection and the viral load quantification of RVA were performed using real-time reverse transcription polymerase chain reaction (RT-PCR). The virological results showed in general that RVA were detected at high frequency of 98% (137/140). In fact, the RVA detection rates at the exit of the two studied wastewater treatment were about 100% at the exit of the activated sludge procedure. It means that all wastewater sampled at this last step of treatment was positive for RVA detection. On the other hand, 92.5% of the wastewater samples taken at the exit of the monolamp UV-C₂₅₄ reactor were positive for the RVA. However, the RVA quantification results expressed as viral load showed a significant reduction in the means of RVA viral loads at the exit of the biological activated sludge procedure and the tertiary UV-C₂₅₄ treatment, showing in general an improved treated wastewater virological quality. Therefore, the RVA load removal rates recorded at the two successive stages of treatment, the activated sludge and the UV-C₂₅₄ treatment, were around 85% and 73%, respectively, as compared to the one with 100% registered for the raw wastewater. In addition, good physical-chemical and bacteriological qualities of the treated sewage were found at the exit of the two considered wastewater treatment procedures. The present investigation represents the first Tunisian environmental report showing the good effectiveness and performance of the biological and the tertiary treatments for RVA removal. Therefore, an improved and an optimized tertiary disinfection treatment was needed since it could be a good means for getting better viral water quality and for minimizing the transmission and dissemination of human infectious viral diseases.

mcr-1 encoding colistin resistance in CTX-M-1/CTX-M-15- producing Escherichia coli isolates of bovine and caprine origins in Tunisia. First report of CTX-M-15-ST394/D E. coli from goats

The objective of this study was to isolate and characterize ESBL-producing Escherichia coli (ESBL-EC) from raw bovine and caprine milk samples, as well as from bovine faeces in Tunisia. Therefore, 120 bovine faecal samples and 9 caprine raw milk samples were collected from 2 extensive dairy-cow-farms and 5 ovine farms, respectively. In addition, 94 raw bovine milk samples, from containers and holding tanks from 50 small public-markets in the North of Tunisia, were processed for the isolation of cefotaxime-resistant E. coli (CTX^R). Antimicrobial susceptibility testing was carried out by disc-diffusion/broth-microdilution methods. The presence of genes encoding ESBL, as well as those encoding colistin (mcr-1 to 5 genes)- sulfonamide-, tetracycline-, gentamicin-, quinolone and chloramphenicol-resistance and class 1 integrons were tested by PCR (and sequencing in some cases). ESBL-EC isolates were further characterized by phylogrouping and MLST/PFGE typing. Eight samples (3.6%) contained ESBL-EC isolates (3/2 from raw bovine/goat milk and 3 from cattle faeces) and one isolate/sample was characterized. Four ESBL-EC isolates, all of bovine origin (3 faeces/1 milk), were resistant to colistin (MIC: 8-16 μg/ml), harboured the mcr-1 gene and carried IncP- and IncFIB-type plasmids. The 8 ESBL-EC strains had the following characteristics: a) bovine faeces: mcr-1/CTX-M-1/D-ST1642 (3 strains); b) raw milk: mcr-1/CTX-M-1/A-ST10 (1 strain); CTX-M-15/B1-ST394 (3 strains), and CTX-M-15/A-ST46 (1 strain). Most of bovine ESBL-EC isolates were multidrug-resistant (4/5). Our results showed that ESBL-EC were detected in bovine and caprine samples (CTX-M-1/CTX-M-15 producers), being some of them colistin-resistant (associated with mcr-1 gene), and they belonged to international clonal lineages.

Detection of Sapoviruses in two biological lines of Tunisian hospital wastewater treatment

The efficiency of rotating biodisks and natural oxidizing lagoon procedures is investigated at a Tunisian semi-industrial pilot plant, El Menzeh I, where the wastewater is mainly provided by three different neighbouring hospital clinics. Throughout 2011, 102 wastewater samples were collected from the two mentioned wastewater treatment procedures. Results showed that the Sapovirus (SaV) frequency was approximately 29.4% using the real-time reverse transcription polymerase chain reaction (RT-PCR) technique, and about 16.6% using the conventional RT-PCR. Also, the SaV genogroups and genotypes were identified and genotyping revealed that all of the four Tunisian SaV strains obtained belonged to the two genogroups GIV.1 and GGI.3. In addition, two new genotypes, D and C, were detected. A moderate decrease in the SaV frequencies was observed at the exit of the two treatment processes and the SaV removal rate was around 90% in the natural oxidizing lagoons and 94% in the rotating biodisks procedure showing the temperate sensitivity of these viruses to the implemented biological wastewater. Therefore, an urgent disinfection process should be implemented downstream of the two biological treatment procedures for safe release of treated effluent in the different natural environments. Abbreviations: NoV: Noroviruses; SaV: Sapoviruses; EC: Electrical Conductivity; COD: Chemical Oxygen Demand; BOD5: Biological Oxygen Demand; SS: Suspended Solids; NH4-N: Ammonium Nitrogen; P-PO4: Ortho-Phosphate; AlCl3: aluminum chloride.

High occurrence of enterotoxigenic isolates and low antibiotic resistance rates of Staphylococcus aureus isolated from raw milk from cows and ewes

This study aimed to analyse the frequency of genes encoding virulence factors and to characterize resistance profiles of Staphylococcus aureus isolated from raw milk. In total, 47 and 9 S. aureus isolates were recovered from 150 and 100 raw bovine and ovine milk samples, respectively, in Tunisia. The majority of isolates was resistant to penicillin, and no methicillin-resistant S. aureus was detected. Eighteen and two isolates harboured etd and eta genes respectively. Sixteen enterotoxin-encoding genes were detected (n, %): sed (25, 44·6%), sec (16, 28·6%), sei (16, 28·6%), seh (13, 23·2%), seln (13, 23·2%), sell (10, 17·8%), seg (9, 16%), selu (8, 14·3%), selq (7, 12·5%), selo (7, 12·5%), selm (7, 12·5%), seb (7, 12·5%), sea (6, 10·7%), selk (3, 5·4%), ser (1, 1·8%) and selp (1, 1·8%). Ten isolates carried the tsst1 gene. All isolates carried the haemolysin toxin (hla, hld and hlg). The immune evasion cluster system-type B was predominant (20 isolates) followed by C (3 isolates), A and E (1 isolate each). The occurrence of enterotoxigenic S. aureus in raw milk constitutes a potential risk for human health. SIGNIFICANCE AND IMPACT OF THE STUDY: This paper describes the characteristics of Staphylococcus aureus isolated from raw milk samples from healthy cows and ewes collected from small family farms in Tunisia. Fifty-six strains were analysed by determining their antibiotic susceptibility and genes encoding antibiotic resistance and virulence factors. Methicillin-resistant strains were not detected, and overall low level of antimicrobial resistance was reported. However, our strains harboured several genes encoding virulence factors and 87·5% of them carried at least one gene encoding for enterotoxins showing a high risk of spread of food-borne diseases.

Epizootic haemorrhagic disease virus circulation in Tunisia

Epizootic haemorrhagic disease virus (EHDV) was detected for the first time in Tunisia and in other Northern African countries in 2006. The objective of the present study was to investigate whether EHDV circulated in Tunisian livestock before and after the officially-reported outbreak of 2006. Thus, serum samples from cattle and dromedaries collected in different time periods (before and after 2006) and from different regions of Tunisia were screened for the presence of EHDV antibodies. Serological investigations conducted on cattle and dromedary sera collected in 2000 and 2001 demonstrated no virus circulation on these dates. However, viral circulation was evidenced in 2012 and 2013, although no EHDV cases were officially reported in these years. Serum-neutralization assessed on few ELISA positive samples, confirmed the presence of antibodies against EHDV serotype 6, which was the serotype involved in the EHDV outbreak in the Maghreb region in 2006.

Multidrug Resistance and the Predominance of blaCTX-M in Extended Spectrum Beta-Lactamase-Producing Enterobacteriaceae of Animal and Water Origin

The aim of this work was the genetic characterization of cefotaxime-resistant enterobacteria from animals (53 samples), the surface water of rivers (17 samples), and wastewater treatment plants (43 samples) in Tunisia. A total of 48 (42.4%) cefotaxime-resistant isolates were recovered. An extended spectrum beta-lactamase (ESBL) phenotype with a positive double-disk synergy test (DDST) was exhibited by 34 (70.8%) and 14 (29.1%) isolates from water and animal origins, respectively. Isolates from water were identified as: Escherichia coli (n = 17), Hafnia spp. (n = 13), Citrobacter spp. (n = 1), Enterobacter cloacae (n = 1), Klebsiella pneumoniae (n = 1), and K. oxytoca (n = 1). Animal isolates were identified as: E. coli (n = 11), E. cloacae (n = 1), Hafnia spp. (n = 1), and K. pneumoniae (n = 1). PCR investigation of blaCTX-M, blaTEM, and blaSHV genes showed that amongst the 48 isolates with a positive DDST, 41 (87.5%) carried the blaCTX-M gene, 1 isolate harbored the blaSHV gene, and 1 isolate coharbored blaCTX-M with blaSHV genes. The class 1 and 2 integrons were detected in 27 (56.2%) and 1 (2%) isolates, respectively. Our study showed a significant occurrence of ESBL-producing enterobacteria in animals and aquatic environments with a predominance of blaCTX-M genes.