Colistin Resistance Genes in Broiler Chickens in Tunisia

Simple Summary The extensive use of colistin in livestock is recognized as the main cause of the emergence of colistin resistance in Gram-negative bacteria. This phenomenon represents a public health concern, as colistin is one of the last-resort antibiotics against multidrug-resistant deadly infections in human medicine. In the present survey, DNA extracted from cloacal swabs from 195 broiler chickens in Tunisia was tested by PCR for the ten mobilized colistin resistance (mcr) genes known so far. Of the 195 animals tested, 81 (41.5%) were mcr-1 positive. These results confirm the urgent nature of antimicrobial resistance in the Tunisian poultry sector and suggest the need for cautious use of colistin in the veterinary field. Colistin is a polymyxin antibiotic that has been used in veterinary medicine for decades, as a treatment for enterobacterial digestive infections as well as a prophylactic treatment and growth promoter in livestock animals, leading to the emergence and spread of colistin-resistant Gram-negative bacteria and to a great public health concern, considering that colistin is one of the last-resort antibiotics against multidrug-resistant deadly infections in clinical practice. Previous studies performed on livestock animals in Tunisia using culture-dependent methods highlighted the presence of colistin-resistant Gram-negative bacteria. In the present survey, DNA extracted from cloacal swabs from 195 broiler chickens from six farms in Tunisia was tested via molecular methods for the ten mobilized colistin resistance (mcr) genes known so far. Of the 195 animals tested, 81 (41.5%) were mcr-1 positive. All the farms tested were positive, with a prevalence ranging from 13% to 93%. These results confirm the spread of colistin resistance in livestock animals in Tunisia and suggest that the investigation of antibiotic resistance genes by culture-independent methods could be a useful means of conducting epidemiological studies on the spread of antimicrobial resistance

Occurrence of chicken infectious anemia virus in industrial and backyard tunisian broilers: Preliminary results

Chicken infectious anemia virus (CIAV) is an economically important and widely distributed immunosuppressive agent in chickens. This study performed an epidemiological investigation on CIAV circulation in 195 Tunisian broilers, belonging to 13 lots from five industrial farms and in one rural farm. Fifteen animals were detected positive by a VP1 nested PCR. The amplicons were molecularly characterised by complete genome sequencing. All positive samples obtained in this study were from the rural farm, whereas the industrial farms sampled were negative. Nucleotide and amino acid sequence analyses showed a high degree of similarity among the sequences obtained, suggesting the circulation of a single CIAV strain in the positive lot. Phylogenetic analysis based on the CIAV VP1 nucleotide sequence and/or the complete genome showed that the sequences obtained in this study clustered with CIAV strains previously detected in Tunisia, Italy and Egypt, belonging to genogroup II. Our results highlight the need for constant CIAV surveillance in backyard chicken production

Presence of sandfly-borne phleboviruses of two antigenic complexes (Sandfly fever Naples virus and Sandfly fever Sicilian virus) in two different bio-geographical regions of Tunisia demonstrated by a microneutralisation-based seroprevalence study in dogs

International audienceBACKGROUND: Sandfly-borne phleboviruses are present in North Africa where they can infect humans in regions where Leishmania infantum, the causative agent of zoonotic visceral leishmaniasis in the Western Mediterranean basin is present affecting both humans and dogs. We investigated the capacity of dogs to be used as sentinels for sandfly-borne phleboviruses as previously shown for leishmaniasis.FINDINGS: A total of 312 sera were collected from guard dogs in two different bioclimatic regions (governorates of Kairouan and Bizerte) of Tunisia where zoonotic visceral leishmaniasis has been reported. These sera were tested for the presence of neutralising antibodies against 3 phleboviruses: Toscana virus, Punique virus and Sicilian virus. In the governorate of Kairouan, seroprevalence rates of 7.5%, 43.5%, and 38.1% were observed for Toscana, Punique and Sicilian virus, respectively. A high proportion of sera from the governorate of Bizerte were hemolyzed and showed high cytotoxicity for the cells and subsequently precluded detailed interpretation of this batch. However, validated results for 27 sera were in agreement with data observed in the governorate of Kairouan.CONCLUSIONS: Toscana virus is present in the governorate of Kairouan but at a lower rate compared to Punique and Sicilian viruses. These three sandfly-borne phleboviruses can infect dogs. Direct detection and isolation of the viruses are now to be attempted in animals as well as in humans. Our findings showed that guard dogs are good sentinels for virus transmitted by sandflies and strongly suggested that the high seroprevalence rates observed in dogs merit further attention

Eucalyptus globulus extract protects upon acetaminophen-induced kidney damages in male rat

Plants have historically been used in treating many diseases. Eucalyptus globules, a rich source of bioactive compounds, and have been shown to possess antioxidative properties. The purpose of this study, carried out on male Wistar rats, was to evaluate the beneficial effects of Eucalyptus globulus extract upon acetaminophen-induced damages in kidney. Our study is realized in the Department of Biology, Faculty of Sciences of Sfax (Tunisia). 32 Wistar male rats; were divided into 4 batches: a control group (n=8), a group of rats treated with acetaminophen (900 mg/kg) by intraperitoneal injection during 4 days (n=8), a group receiving Eucalyptus globulus extract (130 mg of dry leaves/kg/day) in drinking water during 42 days after 2 hours of acetaminophen administration (during 4 days) (n=8) and group received only Eucalyptus (n=8) during 42 days. After 6 weeks, animals from each group were rapidly sacrificed by decapitation. Blood serum was obtained by centrifugation. Under our experimental conditions, acetaminophen poisoning resulted in an oxidative stress evidenced by statistically significant losses in the activities of catalase (CAT), superoxide-dismutase (SOD), glutathione-peroxidase (GPX) activities and an increase in lipids peroxidation level in renal tissue of acetaminophen-treated group compared with the control group. Acetaminophen also caused kidneydamage as evident by statistically significant (p<0.05) increase in levels of creatinine and urea and decreased levels of uric acid and proteins in blood. Histological analysis demonstrated alteration of proximal tubules, atrophy of the glomerule and dilatation of urinary space. Previous administration of plant extract is found to alleviate this acetaminophen-induced damage

Cactus (Opuntia ficus indica f. inermis) fruit juice protects against ethanol-induced hematological and biochemical damages in rats

A putative beneficial effect of Opuntia ficus indica f. inermis prickly pear juice (OFIj) was tested on ethanol-induced hematological and biochemical damages in rats. Our results show that chronic ethanol treatment (300 mg/100 g body weight for 90 days) of Wistar rats (group 2) significantly reduced red blood cells (RBC) and platelet (Plt) counts, hemoglobin (Hb) content, mean corpuscular hemoglobin (MCH) and mean corpuscular hemoglobin concentration (MCHC) whereas white blood cells (WBC) counts and the mean corpuscular volume (MCV) significantly increased as compared to the controls rats treated with same distilled water (group 1). In addition, serum activities of alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphatase (ALP), lactate dehydrogenase (LDH) and γ-glutamyl transpeptidase (γ-GT) as well as urea, creatinine, cholesterol and triglycerides concentrations significantly increased in ethanol-fed rats. Furthermore, serum, hepatic and renal lipid peroxidation levels were also increased in animals given ethanol compared to the controls. In alcoholic rats co-treated with 4 ml OFIj / 100 g b.w. (group 3), all the above cited parameters were maintained to near-normal values. In group 4 only 4 ml OFIj / 100 g b.w. was given, no changed parameters was shown. Therefore, OFIj appeared to be a promising agent for protection against ethanol toxicity.Key words: Opuntia, alcohol, blood, liver, kidney, toxicity

Effects of MgCl2 supplementation on blood parameters and kidney injury of rats exposed to CCl4

The purpose of this study was to evaluate the beneficial effects of magnesium (Mg) supplementation upon carbon tetrachloride (CCl4) toxicity. Our study was carried out on 24 Wistar male rats divided into 4 batches. During a 6 week period, one group served as a control, two groups received Mg (after 4 weeks one of these groups was then treated with CCl4), and a final group was treated with CCl4 only. Under our experimental conditions, CCl4 poisoning resulted in oxidative stress indicated by a significant increase in lipid peroxidation level in renal tissues. The blood levels of creatinine and urea increased while the blood level of uric acid and proteins decreased. CCl4 also induced an increase in superoxide dismutase (SOD) and glutathione peroxidase (GPX) activity in kidneys, in the number of red blood cells (RBC), and in hemoglobin content (Hb) and mean cell hemoglobin concentration (MCHC). However, white blood cell count (WBC), platelet count (Pl) and catalase activity (CAT) all decreased significantly. Treatment with Mg was found to alleviate most of CCl4-induced damage by decreasing lipid peroxidation and by correcting changed hematological parameters, and catalase, glutathione peroxidase and superoxide-dismutase activities. The results provide strong evidence that Mg supplementation is beneficial in protecting the kidneys from CCl4 toxicity

Colistin Resistance Genes in Broiler Chickens in Tunisia

Colistin is a polymyxin antibiotic that has been used in veterinary medicine for decades, as a treatment for enterobacterial digestive infections as well as a prophylactic treatment and growth promoter in livestock animals, leading to the emergence and spread of colistin-resistant Gram-negative bacteria and to a great public health concern, considering that colistin is one of the last-resort antibiotics against multidrug-resistant deadly infections in clinical practice. Previous studies performed on livestock animals in Tunisia using culture-dependent methods highlighted the presence of colistin-resistant Gram-negative bacteria. In the present survey, DNA extracted from cloacal swabs from 195 broiler chickens from six farms in Tunisia was tested via molecular methods for the ten mobilized colistin resistance (mcr) genes known so far. Of the 195 animals tested, 81 (41.5%) were mcr-1 positive. All the farms tested were positive, with a prevalence ranging from 13% to 93%. These results confirm the spread of colistin resistance in livestock animals in Tunisia and suggest that the investigation of antibiotic resistance genes by culture-independent methods could be a useful means of conducting epidemiological studies on the spread of antimicrobial resistance