characterization and antimicrobial resistance analysis of avian pathogenic escherichia coli isolated from italian turkey flocks

ABSTRACT This study investigated the occurrence of avian pathogenic Escherichia coli (APEC) in a finishing turkey commercial farm, carrying out longitudinal surveys involving 3 consecutive flocks. The diversity and the distribution of the E. coli strains detected during colisepticemia outbreaks were examined. The strains were isolated, serogrouped, assessed for the presence of virulence-associated genes, typed by random amplification of polymorphic DNA (RAPD), and antimicrobial resistance analysis was then carried out. Escherichia coli O78 and O2 were predominantly found. Moreover, based on the somatic antigens used in the study, strains were recovered that were nontypeable. On one occasion, an E. coli O111 strain was found in turkeys. The E. coli isolates differed in terms of antibiotic resistance and RAPD profile. All strains possessed the virulence genes that enabled them to be considered APEC. Strains not only differed between flocks, but also within the same flock. These findings point out the importance of addressing colibacillosis therapy on the basis of a sensitivity test

Additional data on the population distribution of human serum albumin genes; three new variants

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/66298/1/j.1469-1809.1973.tb01829.x.pd

Epidemiology of Avian pathogenic Escherichia coli (APEC) in a finisching male turkey farm: longitudinal survey of three consecutive production cycles.

The purpose of this study was to investigate the epidemiology of APEC (Avian Pathogenic Escherichia coli), in a finishing male turkey commercial farm, conducting longitudinal surveys of three consecutive production cycles. The diversity and the distribution of APEC strains during the production cycles were examined using microbiological and molecular techniques. APEC isolates were serotyped, assessed for the presence of virulence-associated genes (pathogenic potential – pathotype) and for resistance to antibiotics (resistotype). Random Amplified Polymorphic DNA (RAPD) was applied to analyse their genetic relationship. Strains of high genetic homology were grouped into the same RAPD cluster (RAPD type). Sampling included, when colisepticemic or articular lesions were observed, viscera and joints from day one until 14 weeks. In the first cycle, APEC O78 was the most prevalent serotype with all isolates sharing the same resistotype and pathotype. Seven of them were included in the same RAPD cluster indicating high genetic similarity. In this cycle, APEC O111 was detected and this represents, to our knowledge, In the second cycle, APEC O2 isolates predominated at the beginning, while O78 strains appeared later until the end of the survey. APEC O2 were classified in two resistotypes, same pathotype and RAPD type. APEC 078 belonged to three resistotypes, same pathotype and three RAPD types. APEC O78 strains, differently from serotype O2, were detected from both colisepticemic viscera (such as brain, pericardium, lungs) and joints. The articular tropism of this serotype is unique as it was observed only in APEC O78 strains of this cycle and of the previous one. Moreover, RAPD molecular studies identified a specific articular O78 cluster, including two strains, which was different from other RAPD clusters including O78 and O2 colisepticemic strains

Importanza della diagnosi di laboratorio nei casi di zoppia del pollo e del tacchino

L\u2019utilizzo degli strumenti di laboratorio, come descritto in questi tre casi clinici, \ue8 di fondamentale importanza per l\u2019inquadramento diagnostico della zoppia nel pollo e nel tacchino. Il primo caso clinico (A) si \ue8 presentato in un allevamento di polli da carne in cui, dall\u2019et\ue0 di due settimane, una percentuale elevata di soggetti esibiva zoppia monolaterale che non rispondeva a trattamento con vitamina D e calcio. Gli animali mostravano grave discondroplasia tibiale, osteomielite e fragilit\ue0 ossea. Dalle analisi batteriologiche e biomolecolari si dimostrava che l\u2019agente causale della osteomielite era Streptococcus gallolyticus subsp. gallolyticus. La sua scarsa sensibilit\ue0 agli antibiotici ha reso difficile ma non impossibile il successo terapeutico con amoxicillina. \uc9 la prima segnalazione in Italia della presenza di questo batterio nel pollo. Il secondo caso (B) ha coinvolto un allevamento di tacchini da carne maschi. Gli episodi di zoppia, iniziati alla decima settimana di et\ue0, costringevano gli animali a non deambulare correttamente diventando cachettici. Le lesioni comprendevano osteomielite nella testa del femore con artrite purulenta nella articolazione coxofemorale ed alla corrispondente tibiotarsometatarsale. L\u2019isolamento ripetuto in sede di lesione di Escherichia coli sierotipo O78 confermava il suo elevato tropismo per le articolazioni ed il midollo osseo. Tutti gli E. coli O78 isolati sono APEC (Avian Pathogenic E. coli) con una origine clonale diversa da quelli presenti negli organi setticemici. Trattamenti antibiotici mirati o di massa basati sull\u2019antibiogramma sono stati in grado di prevenire nuovi casi o ridurre la gravit\ue0 di quelli gi\ue0 esistenti. Il terzo caso (C) \ue8 stato osservato in un allevamento di tacchini da carne maschi. Gli animali, dall\u2019et\ue0 di 80 giorni, hanno iniziato a presentare difficolt\ue0 di deambulazione. La lesione pi\uf9 comunemente evidenziata era una infiltrazione di essudato lattiginoso non purulento tra i fasci dei muscoli flessori delle dita e i tendini che poco interessava l\u2019articolazione tibiotarsometatarsale. Ornithobacterium rhinotracheale \ue8 stato isolato con difficolt\ue0 dal liquido patologico di un tacchino ma la sua presenza, con PCR, dimostrata da pi\uf9 soggetti