title: Antimicrobial resistance of F4+ Escherichia coli isolated from Swine in Italy.
abstract: Four-hundred and forty-two F4+ pathogenic Escherichia coli were isolated in a period of 10 years (2002-2011), from pigs that were suffering from diarrhoea belonging to Italian swine herds. The strains were analysed for their susceptibility to 12 antimicrobials using the disc diffusion method. During the study period, a statistically significant proportion of isolates resistant to enrofloxacin (14.5-89.3%), marbofloxacin (5.4-60.7%), flumequine (49.1-92.9%), danofloxacin (21.6-80%), florfenicol (9.8-64.3%), thiamphenicol (50-92%) and cefquinome (3.8-44%) was recorded. An increase in resistance (not statistically significant) to gentamicin (63.6-85.7%), apramycin (61.8-82.1%), trimethoprim-sulphamethoxazole (75-89.3%), tetracycline (97-100%) and erythromycin (92.4-100%) was also observed. Based on antimicrobial multiresistance, the strains were collected into three groups: I. resistant to 2-5 antimicrobials; II. resistant to 6-8 antimicrobials; III. resistant to 9-12 antimicrobials. The number of isolates belonging to the first group showed a statistically significant decrease (P < 0.05; R(2)  = 0.896; r = -0.9608), while the isolates belonging to the second and third groups showed a statistically significant increase in resistance (P < 0.05; R(2)  = 0.753; r = 0.8890 and P < 0.05; R(2)  = 0.727; r = 0.8701, respectively) over the period of study. The results of this study suggest the need for continued monitoring of the development of resistance.
authors.affiliation: Istituto Zooprofilattico Sperimentale della Lombardia e dell'Emilia Romagna (IZSLER), Brescia, Italy.
authors.forename: A
authors.initials: A
authors.lastname: Luppi
authors.forename: P
authors.initials: P
authors.lastname: Bonilauri
authors.forename: M
authors.initials: M
authors.lastname: Dottori
authors.forename: Y
authors.initials: Y
authors.lastname: Gherpelli
authors.forename: G
authors.initials: G
authors.lastname: Biasi
authors.forename: G
authors.initials: G
authors.lastname: Merialdi
authors.forename: G
authors.initials: G
authors.lastname: Maioli
authors.forename: P
authors.initials: P
authors.lastname: Martelli
mesh_terms: D000818:Animals; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D000942:Antigens, Bacterial / Q000378:metabolism; D002511:Cephalosporins / Q000494:pharmacology; D003967:Diarrhea / Q000382:microbiology / Q000662:veterinary*; D052978:Disk Diffusion Antimicrobial Tests / Q000662:veterinary; D024881:Drug Resistance, Bacterial; D000077422:Enrofloxacin; D004926:Escherichia coli / Q000145:classification / Q000187:drug effects* / Q000302:isolation & purification; D004927:Escherichia coli Infections / Q000382:microbiology / Q000662:veterinary*; D029968:Escherichia coli Proteins / Q000378:metabolism; D036781:Fimbriae Proteins / Q000378:metabolism; D024841:Fluoroquinolones / Q000494:pharmacology; D007558:Italy / Q000453:epidemiology; D013552:Swine; D013553:Swine Diseases / Q000453:epidemiology* / Q000382:microbiology*; D013839:Thiamphenicol / Q000031:analogs & derivatives / Q000494:pharmacology
chemical_list: D000900:Anti-Bacterial Agents; D000942:Antigens, Bacterial; D002511:Cephalosporins; D029968:Escherichia coli Proteins; D024841:Fluoroquinolones; C026888:K88 antigen, E coli; D036781:Fimbriae Proteins; C068581:danofloxacin; D000077422:Enrofloxacin; C080260:marbofloxacin; C035534:florfenicol; D013839:Thiamphenicol; C012976:flumequine; C068212:cefquinome
keywords: F4+ Escherichia coli; antimicrobial resistance; disc diffusion; pig