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Background: With the increase in human population, the consumption of livestock products such as sheep meat has also increased. Sheep are the reservoir and shedder of Escherichia coli that can be transmitted to humans. Aims: Characterization of fecal E. coli isolated from sheep in slaughterhouse. Methods: Stool specimens were collected from 30 apparently healthy sheep from different flocks in Shiraz industrial slaughterhouse. The resistance of E. coli isolates against 10 antibiotics was determined by disk diffusion method. The presence of three major extended spectrum beta-lactamase (ESBL) genes and five tetracycline resistance genes as well as seven virulence genes were investigated by polymerase chain reaction (PCR) technique. Using the microtiter plate method, the biofilm formation ability of E. coli isolates was investigated. Results: The highest frequency of resistance was to amoxicillin (100%) followed by tetracycline (25%). All E. coli isolates were susceptible to gentamicin and nitrofurantoin, and only one isolate was resistant to the tested third-generation cephalosporins. Multidrug resistance phenotype was observed in 16.7% of the isolates. bla TEM (25%) was the most prevalent ESBL gene and tetA (62.5%) was the most prevalent tetracycline resistance gene in the isolates. crl, csgA, fimH, and bcsA genes were present in all isolates, and the prevalence of papC and afa genes was 95.8% and 83.3%, respectively. In total, 62.5% of the isolates were biofilm producers. Conclusion: According to the concept of One Health, the presence of virulent antibiotic-resistant biofilm producing strains of E. coli in sheep is a risk to public health.

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Knowledge on the characteristics of different infection models of avian colibacillosis is mandatory for performing reliable experimental studies. This study compares the characteristics of two infection models of colibacillosis (by intratracheal and subcutaneous routes) in broilers. Broilers (125), 35 days old, were randomly allocated to four experimental (n = 20) and three control (n = 15) groups: 1) negative control; 2) intratracheal infection control; 3) subcutaneous infection control; 4) intratracheal infection (IT); 5) intratracheal infection with florfenicol administration (ITF); 6) subcutaneous infection (SC); and 7) subcutaneous infection with florfenicol administration (SCF). Clinical signs and mortalities were recorded, and gross examination of carcasses was performed. On days 3 and 5 postchallenge (PC), 5 birds/group were euthanatized. Despite similar onset and type of clinical signs and mortality of birds in the IT and SC groups, especially on early days PC, birds in the SC group had lower body weight than IT birds. Lung injuries were more prominent in the IT group than the SC group. Birds of the SC group showed cellulitis and severely injured kidneys in contrast to the IT group. On day 3 PC, the number of positive heart blood samples for bacterial growth in the ITF group was half that of the IT group, whereas SC and SCF birds had similar positive numbers. Infection by the subcutaneous route results in more severe disease. The intratracheal route produces results more similar to colibacillosis under field conditions with regard to clinical signs, pathogenesis, and response to therapy, albeit it is more difficult to perform than a subcutaneous challenge.

Un estudio comparativo sobre dos modelos de infección de colibacilosis en pollos de engorde: Características clínicas, patogénesis y respuesta a la terapia. El conocimiento de las características de los diferentes modelos de infección de colibacilosis aviar es necesario para realizar estudios experimentales confiables. Este estudio compara las características de dos modelos de infección de colibacilosis (por vía intratraqueal y por vía subcutánea) en pollos de engorde. Pollos de engorde (n = 125), de 35 días de edad, se asignaron aleatoriamente a cuatro grupos experimentales (n = 20) y tres controles (n = 15): 1) control negativo (NC), y grupos 2 y 3) controles de infección intratraqueal o subcutánea (ITC o SCC), 4) infección intratraqueal (IT), 5) infección intratraqueal con administración de florfenicol (ITF), 6) infección subcutánea (SC), y 7) infección subcutánea con administración de florfenicol (SCF). Se registraron los signos clínicos y la mortalidad, y se realizó un examen macroscópico de las canales. En los días tres y cinco posteriores a la exposición (PC), se sacrificaron 5 aves por grupo. A pesar de que fueron similares el inicio y tipo de signos clínicos y la mortalidad en las aves de los grupos inoculados por infección intratraqueal y subcutánea, especialmente en los primeros días después del desafío, las aves de los grupos inoculado por vía subcutánea tenían un peso corporal más bajo que las aves inoculadas por la vía intratraqueal. Las lesiones pulmonares fueron más prominentes en el grupo inoculado por vía intratraqueal que en el grupo inoculado por vía subcutánea. Las aves del grupo inoculado por vía subcutánea mostraron celulitis y riñones severamente lesionados en contraste con el grupo inoculado por vía intratraqueal. En el día tres después del desafío, el número de muestras de sangre del corazón positivas para crecimiento bacteriano en el grupo con infección intratraqueal y con administración de florfenicol fue la mitad que en el grupo inoculado intratraquealmente, mientras que las aves inoculadas por vía subcutánea e inoculadas subcutáneamente con administración de florfenicol tuvieron números positivos similares. En conclusión, la infección por vía subcutánea resulta en una enfermedad más severa. La vía intratraqueal produce resultados más similares a la colibacilosis en condiciones de campo con respecto a los signos clínicos, la patogenia y la respuesta a la terapia, aunque es más difícil de realizar que un desafío subcutáneo.

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BACKGROUND: Uropathogenic Escherichia coli (UPEC) are the principal cause of urinary tract infections (UTIs) which can be either hospital- or community-acquired. The most crucial factor in the persistence and recurrence of UTIs is the biofilm formation ability of UPEC, which protects them against antimicrobial treatment. AIM: To investigate the genetic relatedness, biofilm formation ability, and biofilm-related genes in UPEC isolated from hospital- and community-acquired UTI patients. METHODS: In vitro biofilm formation ability of 100 UPEC isolates, collected from the urine samples of 49 inpatients and 51 outpatients with UTIs, was assessed by the microtitre plate method. The association between the presence of fimH, papC, sfa/focDE, csgA, crl, afa, flu, and bcsA genes and biofilm formation ability of UPEC was statistically analysed. The genetic relatedness of UPEC isolates was evaluated by enterobacterial repetitive intergenic consensus polymerase chain reaction (ERIC-PCR). FINDINGS: Overall, 99% of the UPEC isolates showed in vitro biofilm formation ability, and 27% of the isolates were moderate to strong biofilm producers. Only the presence of sfa/focDE gene was significantly associated with moderate and strong biofilm formation by the UPEC isolates. Analysis of dendrograms revealed higher genetic similarities among UPEC isolates of inpatients compared with outpatients. CONCLUSION: Based on the results, selection of effective therapeutic approaches, which can affect both biofilm formation and enclosed UPEC, is important for preventing recurrent UTIs. The common UPEC clones among inpatients in different hospital units emphasize the need for more rigid control measures to prevent the spread of UPEC in hospitalized patients and to reduce the occurrence of hospital-acquired UTIs.

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AIMS: To determine the prevalence of cross-species sharing of Escherichia coli between healthy dogs and humans living in the same household. METHODS AND RESULTS: Two faecal E. coli isolates from 25 healthy dog-owner pairs and 16 healthy control humans were tested using three fingerprinting methods. The prevalence of within-household sharing of E. coli was 4, 8 and 8% using pulsed-field gel electrophoresis, randomly amplified polymorphic DNA and enterobacterial repetitive intergenic consensus-PCR analyses respectively. Within-household bacterial sharing was more prevalent than across-household sharing (P < 0·05). According to questionnaire analyses avoiding the dog-owner behaviours such as allowing a dog to kiss or lick the owner's face, sharing people food with dog and feeding it raw meat may decrease the chance of cross-species E. coli sharing. CONCLUSIONS: Direct contact between humans and dogs and environmental reservoirs may be important routes for cross-species sharing of bacteria. Good personal hygiene and appropriate veterinary care for pets can minimize this risk. SIGNIFICANCE AND IMPACT OF THE STUDY: Due to the importance of canine pathogenic E. coli reservoir hypothesis, close contacts between humans and dogs raises public health concerns. Determining the rate of cross-species bacterial sharing and confirm its accuracy by different fingerprinting techniques will help to find ways for reducing the economic impact of E. coli infections. This study support claims that public health concerns regarding the cross-species sharing of E. coli are warranted but this risk is minimal.

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