Molecular analysis of enteropathogenic Escherichia coli (EPEC) isolates from healthy food-producing animals and humans with diarrhoea.

Enteropathogenic Escherichia coli (EPEC) is a pathogen associated with acute diarrhoea in humans. To determine whether EPEC isolated from healthy food-producing animals possesses the same virulence gene repertoire as EPEC isolated from human with diarrhoea, we compared six typical EPEC (tEPEC) and 20 atypical EPEC (aEPEC) from humans with diarrhoea and 42 aEPEC from healthy animals (swine, sheep and buffaloes), using pulsed-field gel electrophoresis (PFGE), virulence markers, serotyping and subtyping of eae and tir genes. We found that human and animal isolates shared virulence genes, including nleB, nleE and nleF, which were associated with human diarrhoea. Serogroups and serotypes identified in isolates of food-producing animals such as O26:H11, O128:H2, O76:H7, O103, O108, O111 and O145, have previously been implicated in human disease. The subtypes eae and tir were also shared between human and animal isolates, being eae-γ1 and eae-ß1 the most prevalent in both groups, while the most common tir subtypes were α and ß. Despite PFGE analysis demonstrating that EPEC strains are heterogeneous and there was no prevalent clone identified, EPEC isolated from humans and food-producing animals shared some characteristics, such as virulence genes associated with human diarrhoea, indicating that food-producing animals could play a role as reservoirs for those genes.

Root coverage of multiple gingival recessions treated with coronally advanced flap associated with xenogeneic acellular dermal matrix or connective tissue graft: a 6-month split-mouth controlled and randomized clinical trial.

OBJECTIVES: This study aimed to compare xenogeneic dermal matrix (XDM) to connective tissue graft (CTG) associated with coronally advanced flap (CAF) in treating Miller's class I and II (RT1) multiple gingival recession in a split-mouth randomized clinical trial. MATERIALS AND METHODS: Fifteen patients with bilateral Miller's class I and II multiple recessions were selected. The patient's side receiving each treatment was randomly allocated to receive XDM or CTG. The clinical parameters were measured at baseline and 6 months of follow-up. RESULTS: At 6 months, no significant difference in the root coverage (RC) (95.28 ± 6.89% for CTG and 92.68 ± 7.35% for XDM) and the keratinized tissue (KT) gain (0.91 ± 0.46 mm for CTG and 0.74 ± 0.39 mm for XDM) was observed between groups (p > 0.05). The CTG group presented higher complete root coverage (CRC) than XDM (60% and 33%, respectively) (p = 0.045). Multiple logistic regression indicated that the XDM (p = 0.01) and the XDM and KT interaction (p = 0.02) negatively interfered in the CRC. A 1-mm increase in the baseline KT when using XDM increases almost 6 times the chance of achieving CRC, and XDM reached a similar CRC probability to CTG when the receptor area presented at least 2 mm of KT. CONCLUSIONS: Both treatments were effective for treating multiple gingival recession; similar KT gain, GR reduction, and RC were obtained for CTG and XDM, while CTG promoted higher CRC than XDM. Moreover, the amount of KT at baseline was determinant for CRC when treating multiple gingival recession with XDM. CLINICAL RELEVANCE: XDM produces limited CRC in sites with a reduced amount of KT. TRIAL REGISTRATION: Brazilian Clinical Trials Registry (REBEC) number RBR-56NZQ6.

Comparative Analysis Using Pulsed-Field Gel Electrophoresis Highlights a Potential Transmission of Salmonella Between Asymptomatic Buffaloes and Pigs in a Single Farm.

Buffaloes and pigs play an important epidemiological roll in the Salmonella infection cycle, and asymptomatic animals can act as key component in the dissemination of the disease by horizontal, vertical, and cross-species transmission. Our study aimed and was able to confirm evidences of a cross-species transmission of Salmonella Agona between asymptomatic buffaloes and pigs. Also, we described Salmonella infection within the pig production phases, involving serotypes Agona, Senftenberg and Schwarzengrund. Rectal samples were collected from Jafarabadi buffaloes (n = 25) and Piau pigs (n = 32), located on a single farm. Salmonella Agona was isolated from lactating buffaloes, gilts, pregnant sows, and weaned pigs, Salmonella Schwarzengrund from lactating sows and Salmonella Senftenberg from gilts, pregnant sows, lactating sows, and weaned pigs. Pulsed-field Gel Electrophoresis protocol (PFGE) was performed and revealed four different profiles. Profile 1 (Salmonella Agona), isolated from a pregnant sow, a gilt and two lactating buffaloes, revealed a indistinguishable PFGE pattern, confirming evidences of potential cross-species transmission. Profile 2 (Salmonella Agona), 3 (Salmonella Senftenberg), and 4 (Salmonella Schwarzengrund), isolated from pigs, revealed important indistinguishable PFGE patterns, evidencing Salmonella infection within the pig production phases. Considering the epidemiological relevance of buffaloes and pigs in the cycle of Salmonella infection, confirmation of a potential cross-species transmission of Salmonella Agona and potential Salmonella infection within the pig production phases highlights the importance of the correct establishment of preventive health strategies in farms, in special the importance of avoiding contact between buffaloes and pigs, since cross-species transmission can occur, increasing the risk of spreading the disease.

Characterization of CMY-2-type beta-lactamase-producing Escherichia coli isolated from chicken carcasses and human infection in a city of South Brazil.

BACKGROUND: Food-producing animals, mainly poultry, have been associated with the maintenance and dissemination of antibiotic-resistant bacteria, such as plasmid-mediated AmpC (pAmpC)-producing Enterobacteriaceae, to humans, thus impacting food safety. Many studies have shown that Escherichia coli strains isolated from poultry and humans infections share identical cephalosporin resistance, suggesting that transmission of resistance from poultry meat to humans may occur. The aim of this study was to characterize pAmpC-producing E. coli strains isolated from chicken carcasses and human infection in a restrict area and to determine their antimicrobial resistance profiles, and molecular type by multilocus sequence typing (MLST) and pulsed-field gel electrophoresis (PFGE). RESULTS: A total of 14 pAmpC-producing E. coli strains were isolated, including eight strains from chicken carcasses and six strains from human infections (from urine, tissue and secretion). The blaCMY-2 gene was identified in all pAmpC-producing E. coli strains by polymerase chain reaction (PCR) and DNA sequencing. High percentages of strains resistant to tetracycline, nalidixic acid and sulfamethoxazole-trimethoprim (78-92%) were detected, all of which were considered multidrug-resistant. Among the non-beta-lactam resistance genes, the majority of the strains showed tetA, tetB, sulI and sulII. No strain was considered an extended-spectrum beta-lactamases (ESBL) producer, and the blaTEM-1 gene was found in 2 strains isolated from human infection. Six strains from chicken carcasses and four strains from humans infections were linked to an ISEcp1-like element. Through MLST, 11 sequence types were found. Three strains isolated from human infection and one strain isolated from chicken carcasses belonged to the same sequence type (ST354). However, considerable heterogeneity between the strains from chicken carcasses and humans was confirmed by PFGE analysis. CONCLUSION: This study showed the prevalence of E. coli strains producing blaCMY-2 linked to ISEcp1 that were present in both chickens and humans in a restricted area. Our results also suggest the presence of a highly diverse strains that harbor pAmpC, indicating no clonal dissemination. Therefore, continuous monitoring and comparative analyses of resistant bacteria from humans and food-producing animals are needed.

Detecção de Listeria spp de importância em saúde pública em diferentes pontos da obtenção do leite e da elaboração de queijos tipo Minas Frescal / Detection of Listeria spp important in public health from different points of milk obtaining and elaboration of Minas Frescal cheese

Queijos tipo Minas frescal podem veicular microrganismos patogênicos. Este estudo objetivou isolar Listeria spp. e identificar as espécies L. innocua, L. seeligeri, L. ivanovii e L. monocytogenes na obtenção do leite e na elaboração de queijos tipo Minas frescal e detectar a presença de genes de virulência. Foram realizadas coletas em cinco pequenas propriedades rurais produtoras deste tipo de queijo em Jaboticabal-São Paulo. Foram coletadas amostras de suabes de fezes bovinas, amostras de mãos de ordenhador, balde de ordenha, leite, água, superfície de elaboração de queijos, mãos de manipulador do queijo, peneiras, bandejas, fôrmas e escumadeiras. O gênero Listeria spp. teve alta prevalência nas amostras, entretanto, nenhuma das espécies pesquisadas foi identificada. Assim, conclui-se que a presença de Listeria spp. em alta percentagem representa potencial risco de contaminação de Queijos tipo Minas frescal e exige uma vigilância contínua para a presença deste gênero.

Shigatoxigenic and atypical enteropathogenic Escherichia coli in fish for human consumption

ABSTRACT Shigatoxigenic and enteropathogenic Escherichia coli with virulence and multidrug resistance profile were isolated from Nile tilapia. This study finding is of great importance to public health because they help understand this pathogen epidemiology in fish and demonstrate how these animals can transmit E. coli related diseases to humans.

Role of hypothetical protein YicS in the pathogenicity of Avian Pathogenic Escherichia coli in vivo and in vitro.

Avian Pathogenic Escherichia coli (APEC) strains belong to the extra-intestinal pathogenic group of E. coli (ExPEC) that causes colibacillosis in poultry. A variety of putative virulence factors of APEC are recognized as potent causes of pathogenicity, the mechanisms underlying their pathogenicity are still not fully understood. The role of yicS in the virulence of pathogenic E. coli is still unclear. Thus, yicS may be related to biofilm formation, which in some bacteria plays a role in pathogenicity. Therefore, the fact that this gene appears to be under positive selection pressure suggests that yicS may be associated with the pathogenicity of APEC. To better understand the role of yicS protein in APEC biological characteristics and pathogenicity, we deleted yicS in an APEC Swollen Head Syndrome strain (APEC strain SCI-07) and studied its effects by comparing wild type and isogenic mutants through comprehensive in vitro and in vivo assays. We demonstrated that yicS plays a role in pathogenicity of APEC. We suggest that the yicS gene, which encodes an exporter protein, has a significant role in biofilm formation, motility, invasion of CEC-32 and Hep-2 cells and APEC pathogenicity in a day-old chick model.

Shigatoxigenic and atypical enteropathogenic Escherichia coli in fish for human consumption.

Shigatoxigenic and enteropathogenic Escherichia coli with virulence and multidrug resistance profile were isolated from Nile tilapia. This study finding is of great importance to public health because they help understand this pathogen epidemiology in fish and demonstrate how these animals can transmit E. coli related diseases to humans.

Carrier flies of multidrug-resistant Escherichia coli as potential dissemination agent in dairy farm environment.

The life cycle of synanthropic flies and their behavior, allows them to serve as mechanical vectors of several pathogens. Given that flies can carry multidrug-resistant (MDR) bacteria, this study aimed to investigate the spread of genes of antimicrobial resistance in Escherichia coli isolated from flies collected in two dairy farms in Brazil. Besides antimicrobial resistance determinants, the presence of virulence genes related to bovine colibacillosis was also assessed. Of 94 flies collected, Musca domestica was the most frequently found in the two farms. We isolated 198 E. coli strains (farm A=135 and farm B=63), and >30% were MDR E. coli. We found an association between blaTEM and phenotypical resistance to ampicillin, or chloramphenicol, or tetracycline; and blaCTX-M and resistance to cefoperazone. A high frequency (86%) of phylogenetic group B1 among MDR strains and the lack of association between multidrug resistance and virulence factors suggest that antimicrobial resistance possibly is associated with the commensal bacteria. Clonal relatedness of MDR E. coli performed by Pulsed-Field Gel Electrophoresis showed wide genomic diversity. Different flies can carry clones, but with distinct antimicrobial resistance pattern. Sanger sequencing showed that the same class 1 integron arrangement is displayed by apparently unrelated strains, carried by different flies. Our conjugation results indicate class 1 integron transfer associated with tetracycline resistance. We report for the first time, in Brazil, that MDR E. coli is carried by flies in the milking environment. Therefore, flies can act as carriers for MDR strains and contribute to dissemination routes of antimicrobial resistance.

Molecular characterization and potential sources of aqueous humor bacterial contamination during phacoemulsification with intraocular lens implantation in dogs.

Bacterial contamination of the anterior chamber during cataract surgery is one of the main responsible for endophthalmitis postoperative. Phacoemulsification is a less invasive technique for cataract treatment, although it does not exclude the possibility of contamination. In this study, bacterial contaminants of aqueous humor collected pre- and post-phacoemulsification with intraocular lens implantation (IOL) of twenty dogs were identified. As the conjunctival microbiota constitute a significant source of anterior chamber contamination, bacterial isolates from aqueous humor were genetically compared with those present in the conjunctival surface of the patients. Three dogs presented bacterial growth in both aqueous humor and conjunctival surface samples. Bacterial isolates from these samples were grouped according to their genetic profiles by repetitive-element PCR (rep-PCR) and their representatives were identified by 16S rRNA sequencing. Isolates from conjunctival surface were identified as Enterobacter spp., Staphylococcus spp. and S. aureus; and from aqueous humor samples as Enterobacter spp., Pantoea spp., Streptococcus spp. and Staphylococcus spp., respectively in decreasing order of prevalence. According to the rep-PCR analysis, 16.6% of Enterobacter spp. isolates from conjunctival surface were genetically similar to those from aqueous humor. The rest of isolates encountered in aqueous humor were genetically distinct from those of conjunctival surface. The significant genetic diversity of bacterial isolates found in the aqueous humor samples after surgery denoted the possibility of anterior chamber contamination during phacoemulsification by bacteria not only from conjunctival surface but also from different sources related to surgical environment.

Virulence Genes and Antimicrobial Resistance in Escherichia coli from Cheese Made from Unpasteurized Milk in Brazil.

Cow raw milk cheese is widely eaten in Brazil. These products may be contaminated with pathogenic bacteria. In this work, we investigated the presence of Escherichia coli in raw milk cheese from different States in Brazil. From 147 "Minas" cheese samples, 28 cheeses were positive for E. coli. Among 39 E. coli isolates of the cheeses, one was positive for eae and negative for bpfA and efa1/lifA using PCR, and so was classified as atypical Enteropathogenic E. coli (aEPEC). Two other isolates were positive for extraintestinal pathogenic E. coli (ExPEC) genes. The aEPEC isolate belongs to serogroup O127 and was classified in A phylogenetic group, and ExPEC isolates were found in O73:H12 (EC-2 strain) and O64474:H8 (EC-9 strain) serotype. This ExPEC belongs to A and C phylogenetic group, respectively. Most of E. coli strains belonged to Clermont phylogenetic groups A (28.2%), C, and E (23.1%). Six strains (15.4%) of E. coli were positive for group B1 and two (5.1%) for B2. E. coli isolates presented an aggregative (46.0%) and diffuse (12.6%) adherence pattern to HeLa cells, and the other isolates did not show adhesion (41.4%). Four E. coli isolates (10.3%) were shown to produce moderate biofilm. The antimicrobial resistance rate was tetracycline (25.6%), followed by ampicillin (17.9%), cefoxitin (7.7%), nalidixic acid (5.1%), and amoxicillin-clavulanic acid (2.6%). One strain was resistant to three antimicrobials (tetracycline, ampicillin, and nalidixic acid). The presence of these microorganisms, the O127 strain, and a new serogroup in Brazil is a potential risk for public health.

Genome-Wide Survey of Genes Under Positive Selection in Avian Pathogenic Escherichia coli Strains.

The ability to obtain bacterial genomes from the same host has allowed for comparative studies that help in the understanding of the molecular evolution of specific pathotypes. Avian pathogenic Escherichia coli (APEC) is a group of extraintestinal strains responsible for causing colibacillosis in birds. APEC is also suggested to possess a role as a zoonotic agent. Despite its importance, APEC pathogenesis still has several cryptic pathogenic processes that need to be better understood. In this work, a genome-wide survey of eight APEC strains for genes with evidence of recombination revealed that ∼14% of the homologous groups evaluated present signs of recombination. Enrichment analyses revealed that nine Gene Ontology (GO) terms were significantly more represented in recombinant genes. Among these GO terms, several were noted to be ATP-related categories. The search for positive selection in these APEC genomes revealed 32 groups of homologous genes with evidence of positive selection. Among these groups, we found several related to cell metabolism, as well as several uncharacterized genes, beyond the well-known virulence factors ompC, lamB, waaW, waaL, and fliC. A GO term enrichment test showed a prevalence of terms related to bacterial cell contact with the external environment (e.g., viral entry into host cell, detection of virus, pore complex, bacterial-type flagellum filament C, and porin activity). Finally, the genes with evidence of positive selection were retrieved from genomes of non-APEC strains and tested as were done for APEC strains. The result revealed that none of the groups of genes presented evidence of positive selection, confirming that the analysis was effective in inferring positive selection for APEC and not for E. coli in general, which means that the study of the genes with evidence of positive selection identified in this study can contribute for the better understanding of APEC pathogenesis processes.

Wild birds and urban pigeons as reservoirs for diarrheagenic Escherichia coli with zoonotic potential.

In order to describe the role of wild birds and pigeons in the transmission of shiga toxigenic Escherichia coli (STEC) and enteropathogenic Escherichia coli (EPEC) to humans and other animals, samples were collected from cloacae and oropharynx of free-living wild birds and free-living pigeons. Two STEC (0.8%) and five EPEC strains (2.0%) were isolated from wild birds and four EPEC strains (2.0%) were recovered from pigeons. Serogroups, sequence types (STs) and virulence genes, such as saa, iha, lpfA O113, ehxA, espA, nleB and nleE, detected in this study had already been implicated in human and animal diseases. Multidrug resistance (MDR) was found in 25.0% of the pigeon strains and in 57.0% of the wild bird strains; the wild birds also yielded one isolate carrying extended-spectrum ß-lactamases (ESBLs) gene bla CTX-M-8. The high variability shown by PFGE demonstrates that there are no prevalent E. coli clones from these avian hosts. Wild birds and pigeons could act as carriers of multidrug-resistant STEC and EPEC and therefore may constitute a considerable hazard to human and animal health by transmission of these strains to the environment.

Captive and free-living urban pigeons (Columba livia) from Brazil as carriers of multidrug-resistant pathogenic Escherichia coli.

Thirty Escherichia coli isolates from captive and free-living pigeons in Brazil were characterised. Virulence-associated genes identified in pigeons included those which occur relatively frequently in avian pathogenic E. coli (APEC) from commercial poultry worldwide. Eleven of 30 E. coli isolates from pigeons, belonging mainly to B1 and B2 phylogenetic groups, had high or intermediate pathogenicity for 1-day-old chicks. The frequency of multi-drug resistant (MDR) E. coli in captive pigeons was relatively high and included one isolate positive for the extended-spectrum ß-lactamase (ESBL) gene blaCTX-M-8. Pulsed field gel electrophoresis (PFGE) showed high heterogeneity among isolates. There is potential for pigeons to transmit antibiotic resistant pathogenic E. coli to other species through environmental contamination or direct contact.

Variants of astA gene among extra-intestinal Escherichia coli of human and avian origin.

Many Escherichia coli strains harbour astA, which is the gene encoding the enteroaggregative E. coli heat-stable enterotoxin (EAST1). This gene is embedded in a putative transposase (ORF1) and presents polymorphism in diarrheagenic strains. Although astA and orf1 are detected in extraintestinal strains, little is known about polymorphism and differential gene transcription in this pathotype. In the present work, extraintestinal E. coli from humans (ExPEC - Extraintestinal Pathogenic E. coli) and poultry (APEC - Avian Pathogenic E. coli) were assayed to verify the presence of astA/orf1 and possible polymorphisms in these genes. Three astA/orf1 patterns were detected via Sanger sequencing. Pattern 1 was novel and represented an astA pseudogene. Pattern 2 and pattern 3 presented distinct amino acids within the reading frame encoding astA and were identical to the sequences found in EAEC 17-2 and EAEC 042, respectively. Regarding the frame encoding ORF1, all mutations detected in the three patterns were neutral. The transcripts of astA/orf1 in vitro were underregulated in strains possessing the pattern 1 sequence. The results demonstrate that the same astA sequences may be detected in diarrheagenic and extra-intestinal E. coli. However, extraintestinal isolates may also present an astA pseudogene that has not been reported in diarrheagenic E. coli.

Antimicrobial Resistance and Virulence Factors of Escherichia coli in Cheese Made from Unpasteurized Milk in Three Cities in Brazil.

The production of cheeses from unpasteurized milk is still widespread in Brazil, even with a legal ban imposed on its marketing. The manufacture of this cheese is a public health problem, due to the use of raw milk and the poor hygienic conditions throughout the supply chain process. Contamination may occur from several sources and involve several different pathogenic microorganisms, such as Escherichia coli. The latter can cause different clinical manifestations depending on the pathotype involved. Furthermore, some isolates manifest antimicrobial resistance and may be a risk for public health. The purpose of the current study was to investigate the presence of potentially pathogenic E. coli in raw-milk cheese in Brazil and their possible risk to public health. A total of 83 cheeses were collected from three different cities and 169 E. coli isolates were characterized for the presence of enteropathogenic E. coli, Shigatoxigenic E. coli, enterotoxigenic E. coli, extraintestinal pathogenic E. coli (ExPEC) virulence genes, phylogenetic type, antimicrobial resistance, O serogroup, and pulsed-field gel electrophoresis. The number of samples positive for E. coli was highest in Aracaju (90.32%, 28/31). The prevalence of samples positive for potential ExPEC genes was similar for Uberaba and Aracaju (23.07%); the most prevalent ExPEC virulence genes were tsh, iucD, and papC. Isolates from Uberaba had a higher prevalence of resistance to tetracycline (38.46%), amoxicillin/clavulanic acid (58.85%), and ampicillin (61.54%) than the other cities. Overall, antimicrobial resistance genes tetB, blaTEM, and blaCMY-2 were the most prevalent genes (26.32%, 15.79%, and 28.95%, respectively) and the most prevalent serotypes were O4 (8%), 018 (12%), and O23 (8%). Clones originating from the same regions and from different regions were observed. These results emphasize the presence of a potential danger for humans in the consumption of raw-milk cheeses in three cities in Brazil due to the presence of antimicrobial resistance, which should be monitored.

Complete Genomic Sequence of an Avian Pathogenic Escherichia coli Strain of Serotype O7:HNT.

Avian pathogenic Escherichia coli (APEC) is associated with colibacillosis in poultry. Here, we present the first complete sequence of an APEC strain of the O7:HNT serotype and ST73 sequence type, isolated from a broiler with cellulitis. Complete genomes of APEC with distinct genetic backgrounds may be useful for comparative analysis.

Fimbria-Encoding Gene yadC Has a Pleiotropic Effect on Several Biological Characteristics and Plays a Role in Avian Pathogenic Escherichia coli Pathogenicity.

The extraintestinal pathogen termed avian pathogenic Escherichia coli (APEC) is known to cause colibacillosis in chickens. The molecular basis of APEC pathogenesis is not fully elucidated yet. In this work, we deleted a component of the Yad gene cluster (yadC) in order to understand the role of Yad in the pathogenicity of the APEC strain SCI-07. In vitro, the transcription level of yadC was upregulated at 41°C and downregulated at 22°C. The yadC expression in vivo was more pronounced in lungs than in spleen, suggesting a role in the early steps of the infection. Chicks infected with the wild-type and mutant strains presented, respectively, 80% and 50% mortality rates. The ΔyadC strain presented a slightly decreased ability to adhere to HeLa cells with or without the d-mannose analog compared with the wild type. Real-time PCR (RT-PCR) assays showed that fimH was downregulated (P < 0.05) and csgA and ecpA were slightly upregulated in the mutant strain, showing that yadC modulates expression of other fimbriae. Bacterial internalization studies showed that the ΔyadC strain had a lower number of intracellular bacteria recovered from Hep-2 cells and HD11 cells than the wild-type strain (P < 0.05). Motility assays in soft agar demonstrated that the ΔyadC strain was less motile than the wild type (P < 0.01). Curiously, flagellum-associated genes were not dramatically downregulated in the ΔyadC strain. Taken together, the results show that the fimbrial adhesin Yad contributes to the pathogenicity and modulates different biological characteristics of the APEC strain SCI-07.

Characterization and antimicrobial resistance patterns of Escherichia coli isolated from feces of healthy broiler chickens / Padrões da caracterização e resistência a antimicrobianos de Escherichia coli isolada das fezes de frangos de corte saudáveis

Avian pathogenic Escherichia coli (APEC) strains are isolated from lesions of poultry presenting colibacillosis, which is a disease that causes either systemic or localized clinical signs. Such strains share many characteristics with E. coli strains that cause extra-intestinal illness in humans. There is not a consensus on how to define the APEC pathotype with regard to the presence of virulence traits. On the other hand, in the past few years, five minimal predictors for APEC detection were proposed. The E. coli isolates in this work were tested through polymerase chain reaction (PCR) to the five proposed minimal predictors and cva C. The strains presenting them were categorized as potential APEC. The APEC and non-APEC categories showed high resistance (> 50%) to cephalotin, erythromycin, streptomycin, sulphametoxazol/trimethoprim, ampicillin, and amoxicillin. Potential APEC strains were significantly more resistant to cephalotin (p < 0.05) and neomcycin (p < 0.01) than non-APEC. These latter were significantly more resistant to tetracycline (p < 0.01) than the potential APEC strains. These results demonstrate that feces of poultry present E. coli strains with resistant features, showing or not the potential of causing colibacillosis in poultry. Because APEC and extra-intestinal illness in humans may be similar, these resistant strains are of interest to public health.(AU)

Cepas de Escherichia coli patogênica para aves (APEC) estão isoladas das lesões de frangos com colibacilose, uma doença que causa sinais clínicos sistêmicos ou localizados. As APEC compartilham algumas características com as cepas de Escherichia coli que produzem doenças extraintestinais nos seres humanos. Ainda não há um consenso sobre a definição de patotipos das cepas de APEC, no que diz respeito à presença das características de virulência. Entretanto, nos últimos anos, foram definidos cinco indicadores mínimos para a identificação de patotipos das cepas de APEC. Os isolados de E. coli utilizados neste trabalho foram testados por meio de reação em cadeia de polimerase (PCR) para os cinco indicadores mínimos e para cva C. Os isolados que possuíam os cinco indicadores mínimos foram definidos como potenciais cepas de APEC. As categorias APEC e não APEC apresentaram alta resistência (> 50%) à cefalotina, eritromicina, estreptomicina, sulfametoxazol mais trimetoprim, ampicilina e amoxicilina. Possíveis cepas de APEC foram significativamente mais resistentes à cefalotina (p < 0,05) e neomicina (p < 0,01) do que as cepas não-APEC. Estas foram significativamente mais resistentes à tetraciclina (p < 0,01) do que as possíveis cepas de APEC. Esses resultados demonstram que as fezes dos frangos de corte albergam cepas de E.coli com características de resistência, apresentando ou não potencialidade de causar colibacilose. Em função das características de similaridade entre APEC e doenças extraintestinais nos seres humanos, estas cepas resistentes são de interesse à saúde pública.(AU)

Frequencies of virulence genes and pulse field gel electrophoresis fingerprints in Escherichia coli isolates from canine pyometra.

Escherichia coli is the most common bacterial agent isolated from canine pyometra. The frequencies of 24 virulence genes and pulsed field gel electrophoresis (PFGE) profiles were determined for 23 E. coli isolates from cases of canine pyometra in Brazil. The frequencies of virulence genes were 91.3% fimH, 91.3% irp-2, 82.6% fyuA, 56.5% iroN, 47.8% traT, 39.1% usp, 34.8% sfaD/E, 34.8% tsh, 30.4% papC, 30.4% hlyA, 26.1% papGIII, 26.1% cnf-1, 21.7% papE/F, 21.7% iss, 17.4% iutA, 17.4% ompT, 17.4% cvaC, 17.4% hlyF, 17.4% iucD, 13.0% iucC, 13.0% astA, 4.3% papGII, 0% afaB/C and 0% papGI. The high frequency of yersiniabactin (fyuA and irp2) and salmochelin (iroN) genes suggests that iron uptake systems might be important in the pathogenesis of canine pyometra. PFGE profiles of 19 isolates were heterogeneous, confirming that E. coli isolates from canine pyometra are unlikely to be epidemic clones.