Phylogenetic characterization of serum plus antibiotic-resistant extraintestinal Escherichia coli obtained from the liver of poultry carcasses in Pernambuco / Caracterização filogenética de Escherichia coli extraintestinal soro- e antibiótico-resistentes isoladas do fígado de carcaças de frango em Pernambuco

In this study, avian extraintestinal Escherichia coli obtained from the liver of poultry carcasses approved for human consumption in the State of Pernambuco-Brazil were tested for antibiotic plus serum-resistance. Liver samples (n=110) were obtained from one slaughterhouse and 88 bacterial isolates were identified as Escherichia coli. The antibiotic-resistance profiles of antibiotics used in human and/or veterinary practice were accessed by the disk-diffusion method. Phenotypes with high resistance to streptomycin (84.0%), tetracycline (44.7%), amikacin (29.8%), gentamicin (21.3%) and ciprofloxacin (21.3%) were identified. Resistance to antibiotics such as ceftazidime, amoxicillin-clavulanic acid and imipenem was also recorded. Twenty isolates with distinct antibiotic-resistance and susceptibility profiles were selected for serum resistance assays, phylogenetic characterization and detection of the iss gene. We have shown that multidrug resistant isolates were often simultaneously resistant to broiler and human sera. Phylogenetic characterization of serum- plus antibiotic-resistant isolates have shown three belonging to group D, eleven to group B1, one to group B2, and five to group A. We concluded that commensal E. coli strains isolated from the liver of healthy poultry carcasses can harbor and potentially share multidrug- plus virulence genes found in pathogenic pathotypes. This suspicion was not related to specific phylogenetic groups or presence of the iss gene.(AU)

Neste estudo, isolados de Escherichia coli extraintestinal aviária obtidos a partir do fígado de carcaças de aves aprovadas para consumo humano no Estado de Pernambuco-Brasil foram testados para resistência a antibióticos e soro. As amostras de fígado (n = 110) foram obtidas de um abatedouro, sendo 88 isolados bacterianos identificados como Escherichia coli. Os perfis de resistência a antibióticos de uso humano e/ou veterinário foram determinados pelo método de disco-difusão. Foram identificados fenótipos com alta resistência à estreptomicina (84,0%), tetraciclina (44,7%), amicacina (29,8%), gentamicina (21,3%) e ciprofloxacina (21,3%). A resistência a antibióticos utilizados na medicina humana e/ou veterinária, tais como a ceftazidima, amoxicilina-ácido clavulânico, estreptomicina e imipenem também foi registrada. Vinte amostras com perfis distintos de resistência/sensibilidade a antibióticos foram selecionadas para os ensaios de resistência ao soro, caracterização filogenética e detecção do gene iss. Foi demonstrado que isolados resistentes a múltiplas drogas foram também simultaneamente resistentes ao soro de frangos e ao soro humano. A caracterização filogenética desses isolados mostraram três pertencentes ao grupo D, onze ao grupo B1, um ao grupo B2 e cinco ao grupo A. Conclui-se que E. coli comensais isoladas do fígado de carcaças de aves saudáveis podem abrigar e potencialmente compartilhar genes de resistência a drogas e de virulência encontrados em patotipos patogênicos. Essa suspeita não foi relacionada com grupos filogenéticos específicos ou com a presença do gene iss.(AU)

Coliform risk assessment through use of the clam Anomalocardia brasiliana as animal sentinel for shellfish harvesting areas in Brazil's northeast.

Outbreaks of food-borne diseases related to consumption of contaminated shellfish have been reported in many countries, but not in Brazil, possibly due to deficient reporting. Here we investigated the suitability of the clam Anomalocardia brasiliana as an animal sentinel for coliform monitoring in shellfish harvesting areas of Brazil's northeast. Samples of shellfish meats (40 clams per sample; n = 8 per collection) were collected at random from April 2009 through March 2010 in the bay area of Mangue Seco (state of Pernambuco). The numbers of thermotolerant coliforms were analyzed through the most probable number technique, and these contamination levels were tentatively correlated with the precipitation recorded on the day of sampling or 24 to 48 h beforehand. A. brasiliana shellfish meats from local retail shops (250 g per sample/ n = 3 per market) sold frozen were also investigated from August 2010 through June 2011. We found that the highest coliform contamination levels were correlated with recent rainfall events, limited to 24 h before sampling. However, irrespective of the rainfall level, the mean contamination above the Brazilian legal threshold of < 3 × 10(2) MPN/ 100 g for shellfish harvesting areas ranged from 18.7 to 93.7 % of samples analyzed monthly. Additionally, a large number of samples obtained from retail shops were also highly contaminated by coliforms during rainy periods, and therefore were not proper for human consumption. We conclude that A. brasiliana can be successfully used to monitor the contamination levels of coliforms in shellfish harvesting areas in Brazil's northeast coast.