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Rolo J.,New University of Lisbon | Miragaia M.,New University of Lisbon | Turlej-Rogacka A.,Polish National Medicines Institute | Empel J.,Polish National Medicines Institute | And 8 more authors.
PLoS ONE | Year: 2012

Background: Several studies have addressed the epidemiology of community-associated Staphylococcus aureus (CA-SA) in Europe; nonetheless, a comprehensive perspective remains unclear. In this study, we aimed to describe the population structure of CA-SA and to shed light on the origin of methicillin-resistant S. aureus (MRSA) in this continent. Methods and Findings: A total of 568 colonization and infection isolates, comprising both MRSA and methicillin-susceptible S. aureus (MSSA), were recovered in 16 European countries, from community and community-onset infections. The genetic background of isolates was characterized by molecular typing techniques (spa typing, pulsed-field gel electrophoresis and multilocus sequence typing) and the presence of PVL and ACME was tested by PCR. MRSA were further characterized by SCCmec typing. We found that 59% of all isolates were associated with community-associated clones. Most MRSA were related with USA300 (ST8-IVa and variants) (40%), followed by the European clone (ST80-IVc and derivatives) (28%) and the Taiwan clone (ST59-IVa and related clonal types) (15%). A total of 83% of MRSA carried Panton-Valentine leukocidin (PVL) and 14% carried the arginine catabolic mobile element (ACME). Surprisingly, we found a high genetic diversity among MRSA clonal types (ST-SCCmec), Simpson's index of diversity = 0.852 (0.788-0.916). Specifically, about half of the isolates carried novel associations between genetic background and SCCmec. Analysis by BURP showed that some CA-MSSA and CA-MRSA isolates were highly related, suggesting a probable local acquisition/loss of SCCmec. Conclusions: Our results imply that CA-MRSA origin, epidemiology and population structure in Europe is very dissimilar from that of USA. © 2012 Rolo et al. Source

Soufi L.,Institute of Veterinary Research of Tunisia | Soufi L.,University of La Rioja | Soufi L.,Research Center Biomedica Of La Rioja Cibir | Saenz Y.,Research Center Biomedica Of La Rioja Cibir | And 12 more authors.
Vector-Borne and Zoonotic Diseases | Year: 2012

Thirty-seven Salmonella enterica isolates obtained from poultry meat in Tunisia were included in this study for characterization of antibiotic resistance mechanisms. High percentages of resistance were detected to ampicillin, sulfonamides, tetracycline, nalidixic acid, and streptomycin (32.4%-89.2%), and lower percentages to amoxicillin-clavulanic acid, kanamycin, amikacin, trimethoprim-sulfamethoxazol, and chloramphenicol (2.7%-18.9%). All strains showed susceptibility to ceftazidime, cefotaxime, gentamicin, and ciprofloxacin. Class 1 integrons were detected in 30% of Salmonella isolates, and four different gene cassette arrangements were detected, including genes implicated in resistance to aminoglycosides (aadA1 and aadA2) and trimethoprim (dfrA1). Four different Pc variants (PcW, PcH1, PcH1 TTN-10, PcW TGN-10) with inactive P2 have been found among these isolates. Integron-positive isolates were ascribed to eight different serotypes. A Salmonella Schwarzengrund isolate harbored a new class 1 integron containing the qacH-dfrA1b-aadA1b-catB2 gene cassette arrangement, with the very unusual PcH1 TTN-10 promoter, which has been registered in GenBank (accession no. HQ874651). Different plasmid replicon types were demonstrated among integron-positive isolates: IncI1 (8 isolates), IncN (8), IncP (2), IncFIB (2), and IncFII (2). Ten different pulsed-field gel electrophoresis profiles were detected among the 11 integron-positive isolates and 8 different sequence types were identified by multilocus sequence typing, one of them (registered as ST867) was new, detected in 3 Salmonella Zanzibar isolates. A high diversity of clones is observed among poultry Salmonella isolates and a high proportion of them show a multiresistant phenotype with very diverse mobile genetic structures that could be implicated in bacterial dissemination in different environments. © 2012 Mary Ann Liebert, Inc. Source

Najwa D.,Institute of Veterinary Research of Tunisia | Najwa D.,Laboratory of the National Bone Marrow Transplantation Center | Salah A.M.,Institute of Veterinary Research of Tunisia | Yolanda S.,Research Center Biomedica Of La Rioja Cibir | And 6 more authors.
Journal of Chemotherapy | Year: 2016

Antimicrobial resistance phenotypes, tetracycline, sulphonamide resistance genes, and integrons were analysed in 48 Escherichia coli isolates recovered from urine cultures of diabetic patients in Tunisia. Twenty-one were susceptible to all antibiotics tested. High rates of resistance were observed for amoxicillin (39.5%), trimethoprim-sulphamethoxazole (33.3%), sulphonamide (33.3%), and tetracycline (31.2%). Resistance to imipenem was not detected, and ESBL producing isolates were not recovered. Our analysis assigned 26, 13, 3, and 5 isolates to phylogroups A, B1, B2, and D, respectively. It is worthy to note that all the resistant isolates belonged to phylogroups A (15 isolates) and B1 (12 isolates), while for the 21 susceptible isolates, phylogroups A, B1, B2, and D were found in 11, 2, 3, and 5 isolates, respectively. Among 15 tetracycline-resistant isolates, the tetA and tetB genes were detected in three and four isolates, respectively. Among 17 sulphonamide resistant isolates, 12, 3, and 1 isolates harboured sul1, sul2, and sul3, respectively. sul1 and sul2 genes occurred simultaneously in three isolates. Integrons were detected in 11 isolates. Ten isolates harboured the class 1 integron and three the class 2 integron. The variable regions (VRs) of the class 1 integrons were analysed in the 10 in1-positive isolates, and the following gene cassette arrangements were detected: dfrA12-orfF-aadA2-cmIA1-aadA1-qacH-IS440-sul3 (one isolate), dfrA15-aadA1 (three isolates), dfrA5 (one isolate), dfrA17- aadA5 (one isolate), dfrA1-aadA1 (one isolate), and dfrA14 (one isolate). The VR of class 2 integron was analysed in the in2-positive isolates, and only one gene cassette arrangement was detected, dfrA1-sat-aadA1. Pulsed-field gel electrophoresis (PFGE) analysis of resistant isolates showed that all were unrelated. Our results highlight the moderate antibiotic resistance in the clinical isolates as well as their heterogeneous genetic background. © 2016 Edizioni Scientifiche per l’Informazione su Farmaci e Terapia. Source

Raddaoui A.,Laboratory of the National Bone Marrow Transplantation Center | Raddaoui A.,University of Carthage | Simoes A.S.,New University of Lisbon | Baaboura R.,Laboratory of the National Bone Marrow Transplantation Center | And 9 more authors.
PLoS ONE | Year: 2015

Background Pneumococcal disease, a major cause of morbidity and mortality globally, has higher incidence among young children, the elderly and the immunocompromised of all ages. In Tunisia, pneumococcal conjugate vaccines (PCVs) are not included in the national immunization program. Also, few studies have described the epidemiology of S. pneumoniae in this country and, in particular, no molecular typing studies have been performed. The aim of this study was to evaluate serotype distribution, antimicrobial resistance and clonality of Streptococcus pneumoniae isolated from neutropenic patients in Tunisia. Methods Fifty-nine S. pneumoniae were isolated from infection (n = 31) and colonization (n = 28) sites of patients (children and adults) attending the National Centre of Bone Marrow Transplantation in Tunis between 2005-2011. All isolates were characterized by serotype, antimicrobial resistance pattern and multilocus sequence typing (MLST). Results The majority (66.1%) of the isolates belonged to five serotypes all included in PCVs: 6B, 9V, 14, 19F and 23F. The potential coverage of the 10-valent and 13-valent PCV was of 71.2% and 76.3% respectively. Resistance rates were very high and 69.5% of the isolates were multidrug resistant: non-susceptibility rates to penicillin, amoxicillin and cefotaxime were 66.1%, 40.7%and 27.1%, respectively; resistance rates to erythromycin, clindamycin, tetracycline, chloramphenicol and trimethoprim-sulfamethoxazole, were 69.5%, 61.0%, 37.3%, 22.0% and 67.8%, respectively. The most frequent serotypes had STs characteristic of multidrug resistant international clones known to be highly successful and important causes of pneumococcal infection: Spain 23F-ST81, France 9V/14-ST156, Spain 6B-ST90, 19FST320, and Portugal 19F-ST177. Conclusions The majority of S. pneumoniae strains recovered from immunocompromised patients in Tunisia are representatives of multidrug resistant pandemic clones that express serotypes targeted by PCVs. To contain the burden of pneumococcal disease and improve treatment choices among Tunisian immunocompromised patients PCVs should be offered to all of them. © 2015 Raddaoui et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. Source

Soufi L.,Institute of Veterinary Research of Tunisia | Soufi L.,University of La Rioja | Saenz Y.,Research Center Biomedica Of La Rioja Cibir | Vinue L.,University of La Rioja | And 8 more authors.
International Journal of Food Microbiology | Year: 2011

The antimicrobial resistance phenotype and genotype, the flanking regions of sulphonamide resistance genes and the integrons were analyzed in 166 Escherichia coli isolates recovered from poultry meat in Tunisia. High percentages of resistance were detected to ampicillin, streptomycin, nalidixic acid, sulphonamide and tetracycline (66-95%), and lower percentages to gentamicin, amoxicillin-clavulanic acid and cefoxitin (1-4%). The blaTEM, tet(A)/tet(B), aph(3')-Ia, aac(6')-Ib-cr, aac(3)-II and cmlA genes were identified in 92, 82, 29, 2, 2 and 7 isolates, respectively. Class 1 and/or class 2 integrons were detected in 52% of E. coli isolates and five different gene cassette arrangements were identified in the variable regions of class 1 integrons, which included antimicrobial resistance determinants. Sixty-eight isolates contained the sul1 gene and 37 of them presented this gene into a class 1 integron structure. The sul3 gene was detected associated with non-classic class 1 integrons in 4 out of 46 sul3-positive isolates. The sul2 gene was detected in 66 isolates, 51 of them were linked to strA/B genes in seven different genetic structures. Seventy-three-per-cent of integron-positive isolates presented resistance to at least five different antimicrobial families versus 38.7% of integron-negative isolates. Our study highlights the role of commensal E. coli isolates from poultry meat as an important reservoir for sulphonamide resistance genes and integrons carrying antimicrobial resistance genes. © 2010 Elsevier B.V. Source

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